Руководство по ansys mechanical 2020

1. Интерфейс и работа в Mechanical и/или в MAPDL

• В новой версии появилась возможность импорта и присвоения углов ориентации элементов из внешнего файла, что весьма полезно при работе с не изотропными материалами.

Рисунок 1. Инструмент импорта углов ориентации элементов

• Добавлены логические простые опции для присвоения материалов импортированным дорожкам, диэлектрикам и перемычкам, в том числе и многим объектам сразу.

Рисунок 2. Присвоение материалов дорожкам

Рисунок 3. Присвоение материалов сразу нескольким импортированным объектам

• Добавлена опция импорта иерархии исходной сборки (Assembly Hierarchy), которая автоматически воссоздает группировку геометрии в CAD при импорте.

Рисунок 4. Путь до опции Assembly Hierarchy

Рисунок 5. Настройка для восстановления группировки исходного CAD файла

• Уже пожалуй традиционно добавлены новые трекеры результатов: на этот раз посвященные сходимости и проникающему давлению среды в контакте.

Рисунок 6. Новые трекеры результатов

• При планировании решения на удаленной машине теперь можно также активировать передачу дополнительных файлов в ту или другую сторону.

Рисунок 7. Поля для дополнительных файлов

• Импортированные внешние данные отныне стало можно удалять. Если вдруг у объекта статус только для чтения (Read Only), то его предварительно нужно отключить.

Рисунок 8. Удаление внешних данных

• Объекты Commands для добавления командных вставок теперь доступны для работы с объектами Point Mass, Thermal Point Mass, и Distributed Mass. Нововведение поддерживается решателями MAPDL и RBD.

Рисунок 9. Командные вставки для точечной и распределенной масс.

• При постановке FSI расчета с системой System Coupling, соответствующей объект в дереве Mechanical получил возможность присвоения к целым телам (Body).

Рисунок 10. Присвоение System Coupling Region к объему

• Продолжается интеграция LS-DYNA и Workbench: в новой версии теперь расчет LS-DYNA можно вызвать прямо из окна Mechanical (правда только при включенном ACT).

Рисунок 11. Вызов расчета в LS-DYNA из окна Mechanical

• Для решения задач подмоделирования и расчетов тепловых напряжений в новой версии можно использовать внешний файл с данными (rst или rth) напрямую вместо соответствующей связи на странице проекта Workbench. Такой подход позволяет более гибко использовать данные разных проектов и решателей (файл с данными может быть получен в том числе и из MAPDL). Путь до файла задается в свойствах объекта импортируемой нагрузки Import Load.

Рисунок 12. Выбор внешнего файла в качестве импортируемой нагрузки

• Среди инструментов умного выбора появился новый – возможность выбирать геометрию в одной плоскости, по одной совпадающей координате, т.е. более строгий подход, чем просто by Same Location.

Рисунок 13. Новые инструменты умного выбора (согласно плоскости)

Рисунок 14. Результат применения опции выбора поверхностей в одной плоскости с одинаковой координатой X.

• Во вкладке Convert To, которая служит для выбора объектов одной топологии на основе объектов другой топологии (например граней, которым принадлежат уже выбранные ребра), добавлена галочка Shared, позволяющая ограничивать выборку только общими объектами для всех выделенных.

Рисунок 15. Результат применения новой опции Shared

• В Mechanical добавлена возможность определять армирование внутри конструкции для 3D Static structural и 3D Steady-state thermal расчетов (шаблон Thermal-stress также поддерживается). Армирование задается независимо от сетки на основе линий (Line Bodies) для дискретного подхода и на основе поверхностей (Surface Bodies) – для размазанного.
  Чтобы указать определенное тело в качестве армирования нужно выбрать его в дереве и далее задать в свойстве Model Type опцию “Reinforcement”

Рисунок 16. Тела для армирования

Рисунок 17. Задание армирования

• Для линий (дискретное армирование), также требуется указать соответствующее сечение Cross Section и материал Material Assignment.
  Для поверхностей (размазанное армирование), опцию однородной мембраны (homogeneous membrane) можно включить “Yes (по умолчанию)” или выключить “No”. Для опции Homogeneous Membrane требуются параметры Thickness и Material Assignment.

Рисунок 18. Настройки армирования

• Опция Homogeneous membrane формирует армирование с плоским напряженным состоянием (structural) или анизотропным тепловым потоком (thermal). Когда опция Homogeneous Membrane выключена “No”, армирование создается с одноосным напряженным состоянием (structural) или одноосным тепловым потоком (thermal). 
  Ориентация армирующего волокна указывается при помощи системы координат соответствующего тела, либо при помощи объекта element orientation.
  В случае когда опция Homogeneous Membrane выключена “No”, потребуется площадь сечения волокна и их расположение для создания армирующего слоя с равноудаленными волокнами.

Рисунок 19. Настройки армирования

• Определение армирования через тела линии и поверхности используется для создания армирующих элементов и в процессе решения эти элементы не представлены в сетке в Mechanical, но будут видны в файле результатов. Объект тепловыделения Heat generation, прикладываемый к телу армирования будет присвоен к слоям/волокнам в процессе решения.
  Результаты на слоях/волокнах армирования можно просматривать путем прикрепления их либо к телам, либо к выборке, состоящей из них.

Рисунок 20. Контурные графики результатов армирования.

• Ранее в Mechanical уже была добавлена возможность приложения давления к Solid телам напрямую без SURF154/SURF153 элементов (опция Direct в свойстве Applied by окна свойств давления). Теперь это работает и для граней элементов оболочек (3D) / ребер(2D).
  При помощи опции “Direct”, нагрузки прикладываются напрямую к граням элементов и, следовательно, улучшается время решения модели, а также используемая память, поскольку surface effect элементы не создаются.  Эта опция не поддерживает наличие в модели трещин Cracks, SMART crack growth, нелинейной адаптивности Nonlinear Adaptive region, метода подконструкций и циклической симметрии.

Рисунок 21. Опция приложения давления напрямую

• Для улучшения точности решения, Mechanical теперь использует MAPDL команду SHSD для shell-solid контакта по умолчанию в конструкционных расчетах.
  Эта команда создает дополнительные контактные элементы для улучшения точности решения.
  Опция поддерживается ТОЛЬКО для Bonded контакта с “MPC” формулировкой и настройкой Constraint type  — “Projected”, “Displacement Only” или “Projected U to ROT”.

Рисунок 22. Настройки для улучшенной работы Shell-Solid контакта.

Рисунок 23. Shell solid контакт в сочетании с SHSD командой обладает улучшенной точностью решения (за счет создания более гладких результатов)

• Опция сохранения именованных наборов (preserve named selections) в процессе решения задачи с нелинейной адаптивностью сетки (non-linear adaptive region), которая вызывает перестроение сетки в процессе решения, больше не является бета функцией – она переехала в основной функционал.

Рисунок 24. Опция для сохранения именованных наборов при перестроении сетки

Рисунок 25. Сохранение именованных наборов.

• Удаленные граничные условия, а именно Remote Displacement, Remote Force и Moment можно прикреплять к телам с нелинейной адаптивностью Non-linear Adaptive Region. Поддерживаются все три типа поведения deformable, coupled и rigid.
• Static structural расчет в Workbench Mechanical теперь позволяет определять расчет как квазистатический. Такой расчет предполагается использовать вместо Transient, когда в задаче переходный процесс является очень медленным.
  В Quasi Static задаче используется алгоритм Backward-Euler, а также рассматриваются диссипативная энергия (damping energy) и выполненная работа внешних сил.

Рисунок 26. Свойство для включения квазистатического расчета

• Кроме того, квазистатический расчет теперь поддерживается при любой физике, т.е. в том числе и в сопряженных расчетах.

Рисунок 27. Сравнение сходимости в квазистатическом и Full Transient подходах в сопряженной задаче.

• В задаче с давлением теперь можно учесть изменение площади приложения при деформировании. Для этого добавлена настройка Loaded Area с вариантами Deformed и Initial.
  Опция “Initial” подразумевает рассматривание выбранной поверхности как постоянной в процессе расчета. При использовании же опции “Deformed”, как раз и учитывается изменение площади поверхности в результате деформирования в ходе расчета. Для обычного объекта давления опция по умолчанию “Deformed”, в то время как опция по умолчанию для импортированного давления — “Initial”.

Рисунок 28. Опция для учета изменения площади приложения давления.

• Настройки перезапуска (Restart controls) в Mechanical теперь поддерживают создание точек перезапуска для определенного шага нагружения. Для реализации требуется выбрать опцию «Specify» и далее указать номер Load Step Number. Если перезапуск выполняется с помощью точки перезапуска внутри шага нагружения, то опция по умолчанию Program Controlled в Auto Time Stepping для этого шага нагружения не будет менять информацию о подшагах или приращениях по времени. Перезапущенное решение в этих случаях использует подшаги или приращения по времени, указанные для предыдущего решения (которое было без перезапуска).

Рисунок 29. Точки перезапуска по шагам

• Для обратного решения (inverse analysis) в Static Structural, Mechanical теперь поддерживает новое свойство с названием Reverse Direction For Inverse Steps и применимо оно только когда все шаги являются обратными. Когда опция включена “Yes”, перемещения прикладываются в противоположном направлении на обратных шагах. Это также сказывается и на графическом отображении – через противоположно направленную стрелку и словом reverse в аннотации.

Рисунок 30. Изменение знака перемещений в обратном решении

• В MSUP harmonic расчете, теперь можно выбрать способ задания демпфирования из двух возможных вариантов: “Damping Ratio” или “Constant Structural Damping Coefficient”. По умолчанию “Damping Ratio”, а когда выбрано “Constant Structural Damping Coefficient”, в решатель MAPDL отправляется команда DMPSTR (В прошлых версиях, только команда DMPR поддерживалась как свойство damping ratio).

Рисунок 31. Выбор подхода к заданию демпфирования

• Все опции Tabular Loading теперь поддерживаются для импортируемых нагрузок в задаче с циклической симметрией.

Рисунок 32. Доступные настройки табличного нагружения в задаче с циклической симметрией.

Рисунок 33. Предварительный показ импортированной нагрузки и результат расчета

• Coupled Field расчеты теперь поддерживают 2D тела с plane stress поведением и неединичной толщиной.
• Данные по максимальной невязке (Maximum residual force) доступны в Solution Information
• Результаты Force Reaction и Moment Reaction Probes теперь поддерживаются вместе с Missing Mass и Rigid Response эффектами для доступных нагрузок RS Base Excitations
• Изменения коснулись также и объекта Bolt Pretension – теперь по умолчанию для 3D случая берется цилиндрический шарнир (cylindrical joint) вокруг оси Z. Иными словами, внутри болта образуется не PRETS179, а MPC184, и работает это не только с болтами из Solid элементов, но и с Beam болтами тоже. Традиционно в узле шарнира обязательно будет создана локальная декартова система координат. Такой подход позволяет получать корректные результаты при больших поворотах болтового соединения.

Рисунок 34. Сравнение старого и нового Bolt Pretension в задаче с большими перемещениями

• Настройки контактных элементов для опций закрывания начальной интерференции больше не зависят от команды KBC. Начальное проникновение или зазор теперь закрываются даже если выбрано пошаговое приложение нагрузки step-applied (по умолчанию в transient).
• Робастность нелинейного решения улучшена для задач с MPC контактом и включенным инструментом predictor. Улучшения особенно видны в ситуациях с большими поворотами или плохой сходимостью.

Рисунок 35. Улучшение сходимости задач с MPC контактом.

• Условие тепловой изоляции или insulated thermal condition (KEYOPT(3) = 2 в target элементе) теперь доступно для расчета с тепловым контактом. Конвекция и излучение в окружающую среду игнорируются, когда контакт открыт в дальнем поле (far-field status).
• Добавлена возможность построения Quad Dominant сетки для 3D размазанного армирования.

Рисунок 36. Сетка из четырехугольников на размазанном армировании

• Добавлена новая команда BFPORT, которая позволяет прикладывать объемную нагрузку на тело (например объемное тепловыделение HGEN) к армирующим элементам в любом месте pre-processing или solution. Таким образом, функционал, требуемый для моделирования PCB с независимым от сетки армированием становится завершенным.
• Добавлен новый элемент для 2D теплового армирования (REINF263), совместимый с 2D тепловыми solid элементами (PLANE292 (2D, 4 узла) и PLANE293 (2D, 8 узлов)). Таким образом, семья элементов армирования для 2D/3D тепловых расчетов становится завершенной.
• Плоские Coupled-field элементы PLANE222 и PLANE223 теперь позволяют вводить толщину и ставить таким образом 2-D plane или plane stress модели.
• Enhanced strain формулировки для SOLID185 (и total и simplified) теперь поддерживаются в обратном расчете (Inverse Solution) как совместно с mixed u/P формулировкой, так и без нее. Таким образом успешно удовлетворены запросы от газотурбинной промышленности, а также значительно расширена применимость обратного расчета и улучшена точность для задач с преобладанием изгиба.

Рисунок 37. Прямое и обратное решение лопатки

• Расширен список моделей материалов, для которых можно выполнить подгон параметров (Curve Fitting) по экспериментальным данным (модели пластичности, ориентированные в числе прочего на задачи термомеханической усталости (TMF)):
  • Chaboche Kinematic Hardening
  • Bilinear Isotropic Hardening
  • Rate Dependent Plasticity с моделями Peryzna, Pierce и EVH
  • Kinematic Static Recovery
  • Isotropic Static Recovery
  • Isotropic Elasticity
• Кроме того, набор данных об одноосном нагружении (Uniaxial Loading) теперь может содержать данные о циклическом и нециклическом поведении, а также в целом увеличена точность и эффективность процесса Curve Fitting.

Рисунок 38. Экспериментальные данные для Curve Fitting в MAPDL

Рисунок 39. Выбор модели для Curve Fitting в MAPDL

• Также для расчетов малоцикловой (LCF) и термомеханической (TMF) усталости добавлен новый инструмент с названием Cycle-Jump, позволяющий ускорять решение таких задач путем «перепрыгивания» части циклов на основе определенного критерия (плавность глобального тренда).

Рисунок 40. Типичное развитие какого-либо параметра решения циклической задачи

Рисунок 41. График развития эквивалентной пластической деформации для двух подходов к решению циклической задачи. Число перепрыгнутых циклов: 57 из 100

Рисунок 42. Cycle-jump решение согласуется с эталонным в конечный момент времени (показано эквивалентное напряжение)

• Улучшено масштабирование для моделей с линейным контактом.

Рисунок 43. Сравнение по производительности на примере модели турбины.

• Поддержка Intel MPI 2018 Update 3 в этой версии не менялась.
• Поддержка IBM MPI в этой версии прекращена.
• Поддержка OpenMPI v3.1.5 является новшеством в этой версии (только для Linux).
• Поддержка Microsoft MPI обновлена с v7.1 на v10.0 (только для Windows).

1. Механика разрушения и метод расчета развития трещины SMART.

• Расчет параметров механики разрушения теперь поддерживает приложение нормальных и касательных усилий на поверхности трещины через команды SF и SFE. Поддерживаются solid элементы 185, 186, и 187 (UMM включен или выключен).

Рисунок 44. Поддерживаемые усилия.

• Подход к моделированию роста трещины SMART теперь можно использовать для трещин смешанного режима разрушения. Поддерживается как статический, так и усталостный рост трещины. Рост трещины смешанного типа основан на критерии максимального окружного напряжения, а для усталостного роста трещины, используется размах эквивалентного коэффициента интенсивности напряжения.

Рисунок 45. Прогноз направления развития трещины смешанного типа

Рисунок 46. Результат моделирования развития трещины методом SMART.

• Метод SMART для расчета роста трещины (статического и усталостного) поддерживает наличие начальной деформации initial strain (определяется она через команду INISTATE,SET,DTYP,EPEL). Как только сетка изменяется из-за перестроения в процессе SMART расчета, начальные деформации накладываются со старой сетки на новую.
• Кроме закона Пэриса, Mechanical теперь также поддерживает еще два закона циклического роста трещины: Walker и Forman, а также табличный ввод напрямую.

Рисунок 47. Моделируемое соотношение размаха коэффициента интенсивности и приращения трещины

• Закон Walker.

• • Модификация закона Пэриса
  • Прогнозирует da/dN на II этапе усталостного роста трещины
  • Учитывает коэффициент асимметрии R
  • Y —  Постоянная материала (обычно около 0.5, но может варьироваться от 0.3 до 1)
  • Логарифмическая интерполяция температуры для постоянной C₀
     
• Закон Forman

• Модификация закона Пэриса
• Прогнозирует da/dN на II и III этапах усталостного роста трещины
• Учитывает эффекты от коэффициента асимметрии R и вязкости разрушения K_C
• Логарифмическая интерполяция температуры для постоянной C₀

1. ANSYS AQWA

• Обновлен инструмент построения графиков результатов: больше гибкости в определении величины для абсциссы, до 20 дополнительных величин для ввода было добавлено, разрешены операции дублирования и копирования графиков.

Рисунок 48. Новые величины для построения графиков в AQWA

• Вся «старая» документация Aqwa Legacy Documentation (по продуктам AQWA вне Workbench) добавлена в общую систему ANSYS Online Help. Теперь там вся документация по AQWA (кроме AqwaGS).

Рисунок 49. Aqwa Legacy Documentation в ANSYS Online Help

1. Явная динамика (Explicit Dynamics и Workbench LS-DYNA)

• Наиболее ярким нововведением в области явной динамики в Workbench является долгожданная поддержка SPH расчетов (гидродинамика гладких частиц) как в Explicit Dynamics, так и в Workbench LS-DYNA. Реализуется через опцию Particle в свойствах геометрического тела и обладает всеми необходимыми аспектами визуализации и настройками в Analysis Settings.

Рисунок 50. Расчет птицестойкости в среде Explicit Dynamics

• Два соответствующих шаблона (Workbench LS-DYNA и Restart Workbench LS-DYNA) были переименованы в LS-DYNA и LS-DYNA Restart

1. LS-DYNA версия 12.0

• Стоит также отметить и ряд некоторых дополнений в новой версии самой LS-DYNA.
• Добавлены модели аккумуляторных модулей (4 модели в зависимости от масштаба/детализации).

• Solid элементы: internal/external shorts, cell
• Оболочки Composite Tshells: internal/external shorts, cell/module
• Макро модель: internal/external shorts, pack/battery
• Бессеточная модель: external shorts, module/pack/battery

• Специально для задач вроде пересечения водных преград вброд была добавлена неявная несжимаемая формулировка SPH (IISPH) – она допускает больший размер шага по времени.

Рисунок 51. Модель пересечения вброд водной преграды

• Добавлены модели парашютов и мембран из пористого материала для 2D и 3D FSI расчетов.

Рисунок 52. Модель парашюта

Рисунок 53. Модель медицинской маски.

• Добавлена возможность связывания электромагнитного решения с ICFD решателем (в частности ICFD сетки можно задавать как проводники). Это может быть полезно для задач электростатики или исследования коротких замыканий, вызываемых попаданием воды. ​

Рисунок 54. Сопряженный EM+ICFD расчет: разъемы аккумулятора закорочены водой

• Для ICFD добавлена первая версия решателя immersed interface solver, пока только в SMP и без FSI, а также возможность создания скользящей сетки.

Рисунок 55. Скользящая сетка

• Кроме того добавлена возможность задания полного набора 2D и 3D регулярных и нерегулярных форм волн для глубоко/средне/мелководных течений воды.

Рисунок 56. Нерегулярные океанические волны (высококачественный рендер результата)

• Добавлен решатель химии литий-ионных аккумуляторов, а также Electrochemistry-Thermal-Mechanical сопряжение.

Рисунок 57. Сопряженный расчет удара по литий-ионному аккумулятору

• Добавлен метод Moment-Consistent Smoothed Particle Galerkin (MC-SPG) широко применяющийся в расчетах разрушения материала и больших перемещений (явный динамический метод, возникший в 2018 году, выпускается впервые в версии 12.0). Кроме того, улучшена точность и эффективность исходного SPG метода, разработанного в 2015 году. Методика поддерживает Thermal-mechanical сопряжение, а также допускается погружение балочных элементов.

Рисунок 58. Расчет сверления кости.

• Методика Structured-ALE поддерживает усечение сеточного домена, а также возможность постановки задачи продолжительного низкоскоростного течения (*EOS_MURNAGHAN). Шаг по времени увеличивается путем снижения скорости звука. Этот подход является физически обоснованным, если сокращенная скорость звука все еще в 10 раз превышает скорость течения.

Рисунок 59. Сравнение результатов расчета птицестойкости в Structured-ALE

• В области NVH стало больше опций для вычисления исходящей акустической мощности (три опции на основе SSD (*FREQUENCY_DOMAIN_SSD)):

• Классический ERP (основан на теории плоской волны)
• Скорректированный ERP (с коррекцией коэффициента излучения)
• Испускаемая мощность по интегралу Рэлея

Рисунок 60. Три результата по излучаемой акустической мощности

• В расчете усталости добавлена возможность моделировать рост усталостного повреждения, а также, соответственно, процесс усталостного разрушения.

Рисунок 61. Модель усталостного разрушения

ANSYS Mechanical User’s Guide

ANSYS, Inc. Southpointe 275 Technology Drive Canonsburg, PA 15317 [email protected] http://www.ansys.com (T) 724-746-3304 (F) 724-514-9494

Release 15.0 November 2013 ANSYS, Inc. is certified to ISO 9001:2008.

Copyright and Trademark Information © 2013 SAS IP, Inc. All rights reserved. Unauthorized use, distribution or duplication is prohibited. ANSYS, ANSYS Workbench, Ansoft, AUTODYN, EKM, Engineering Knowledge Manager, CFX, FLUENT, HFSS and any and all ANSYS, Inc. brand, product, service and feature names, logos and slogans are registered trademarks or trademarks of ANSYS, Inc. or its subsidiaries in the United States or other countries. ICEM CFD is a trademark used by ANSYS, Inc. under license. CFX is a trademark of Sony Corporation in Japan. All other brand, product, service and feature names or trademarks are the property of their respective owners.

Disclaimer Notice THIS ANSYS SOFTWARE PRODUCT AND PROGRAM DOCUMENTATION INCLUDE TRADE SECRETS AND ARE CONFIDENTIAL AND PROPRIETARY PRODUCTS OF ANSYS, INC., ITS SUBSIDIARIES, OR LICENSORS. The software products and documentation are furnished by ANSYS, Inc., its subsidiaries, or affiliates under a software license agreement that contains provisions concerning non-disclosure, copying, length and nature of use, compliance with exporting laws, warranties, disclaimers, limitations of liability, and remedies, and other provisions. The software products and documentation may be used, disclosed, transferred, or copied only in accordance with the terms and conditions of that software license agreement. ANSYS, Inc. is certified to ISO 9001:2008.

U.S. Government Rights For U.S. Government users, except as specifically granted by the ANSYS, Inc. software license agreement, the use, duplication, or disclosure by the United States Government is subject to restrictions stated in the ANSYS, Inc. software license agreement and FAR 12.212 (for non-DOD licenses).

Third-Party Software See the legal information in the product help files for the complete Legal Notice for ANSYS proprietary software and third-party software. If you are unable to access the Legal Notice, please contact ANSYS, Inc. Published in the U.S.A.

Table of Contents Overview ……………………………………………………………………………………………………………………………….. xxv Application Interface …………………………………………………………………………………………………………………. 1 Mechanical Application Window ………………………………………………………………………………………………. 1 Windows Management …………………………………………………………………………………………………………… 2 Main Windows ………………………………………………………………………………………………………………………. 3 Tree Outline ……………………………………………………………………………………………………………………. 3 Understanding the Tree Outline …………………………………………………………………………………….. 4 Correlating Tree Outline Objects with Model Characteristics ……………………………………………….. 6 Suppressing Objects ……………………………………………………………………………………………………. 8 Filtering the Tree ………………………………………………………………………………………………………… 9 Details View …………………………………………………………………………………………………………………… 11 Parameterizing a Variable ……………………………………………………………………………………………. 19 Geometry Window …………………………………………………………………………………………………………. 20 Viewing the Legend …………………………………………………………………………………………………… 21 Discrete Legends in the Mechanical Application ………………………………………………………… 21 Print Preview …………………………………………………………………………………………………………………. 21 Report Preview ………………………………………………………………………………………………………………. 22 Publishing the Report ………………………………………………………………………………………………… 23 Sending the Report …………………………………………………………………………………………………… 23 Comparing Databases ……………………………………………………………………………………………….. 23 Customizing Report Content ……………………………………………………………………………………….. 24 Contextual Windows …………………………………………………………………………………………………………….. 25 Selection Information Window ………………………………………………………………………………………….. 25 Activating the Selection Information Window …………………………………………………………………. 25 Understanding the Selection Modes …………………………………………………………………………….. 26 Using the Selection Information Window Toolbar ……………………………………………………………. 33 Selecting, Exporting, and Sorting Data …………………………………………………………………………… 36 Worksheet Window ………………………………………………………………………………………………………… 38 Graph and Tabular Data Windows ……………………………………………………………………………………… 39 Exporting Data …………………………………………………………………………………………………………. 41 Messages Window ………………………………………………………………………………………………………….. 43 Graphics Annotation Window …………………………………………………………………………………………… 44 Section Planes Window ……………………………………………………………………………………………………. 44 Manage Views Window ……………………………………………………………………………………………………. 44 The Mechanical Wizard Window ………………………………………………………………………………………… 44 Main Menus ……………………………………………………………………………………………………………………….. 44 File Menu ……………………………………………………………………………………………………………………… 44 Edit Menu ……………………………………………………………………………………………………………………… 45 View Menu ……………………………………………………………………………………………………………………. 45 Units Menu ……………………………………………………………………………………………………………………. 47 Tools Menu ……………………………………………………………………………………………………………………. 48 Help Menu ……………………………………………………………………………………………………………………. 48 Toolbars …………………………………………………………………………………………………………………………….. 48 Standard Toolbar ……………………………………………………………………………………………………………. 49 Graphics Toolbar …………………………………………………………………………………………………………….. 50 Context Toolbar ……………………………………………………………………………………………………………… 53 Named Selection Toolbar …………………………………………………………………………………………………. 69 Unit Conversion Toolbar …………………………………………………………………………………………………… 69 Graphics Options Toolbar …………………………………………………………………………………………………. 69 Edge Graphics Options ……………………………………………………………………………………………………. 71 Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Mechanical User’s Guide Tree Filter Toolbar …………………………………………………………………………………………………………… 73 Interface Behavior Based on License Levels ………………………………………………………………………………. 73 Environment Filtering …………………………………………………………………………………………………………… 74 Customizing the Mechanical Application ………………………………………………………………………………….. 74 Specifying Options …………………………………………………………………………………………………………. 74 Setting Variables …………………………………………………………………………………………………………….. 85 Using Macros …………………………………………………………………………………………………………………. 86 Working with Graphics ………………………………………………………………………………………………………….. 86 Selecting Geometry ………………………………………………………………………………………………………… 87 Selecting Nodes …………………………………………………………………………………………………………….. 96 Creating a Coordinate System by Direct Node Selection …………………………………………………. 100 Specifying Named Selections by Direct Node Selection ………………………………………………….. 101 Selecting Elements ……………………………………………………………………………………………………….. 101 Defining Direction ………………………………………………………………………………………………………… 104 Using Viewports …………………………………………………………………………………………………………… 106 Controlling Graphs and Charts ………………………………………………………………………………………… 106 Managing Graphical View Settings …………………………………………………………………………………… 107 Creating a View ……………………………………………………………………………………………………….. 107 Applying a View ………………………………………………………………………………………………………. 108 Renaming a View …………………………………………………………………………………………………….. 108 Deleting a View ………………………………………………………………………………………………………. 108 Replacing a Saved View …………………………………………………………………………………………….. 108 Exporting a Saved View List ……………………………………………………………………………………….. 108 Importing a Saved View List ………………………………………………………………………………………. 109 Copying a View to Mechanical APDL …………………………………………………………………………… 109 Creating Section Planes …………………………………………………………………………………………………. 109 Adding a Section Plane …………………………………………………………………………………………….. 111 Using Section Planes ………………………………………………………………………………………………… 112 Modifying a Section Plane …………………………………………………………………………………………. 113 Deleting a Section Plane …………………………………………………………………………………………… 113 Controlling the Viewing Orientation …………………………………………………………………………………. 113 Viewing Annotations …………………………………………………………………………………………………….. 114 Specifying Annotation Preferences ……………………………………………………………………………… 119 Controlling Lighting ………………………………………………………………………………………………………. 121 Inserting Comments, Images, and Figures ………………………………………………………………………….. 121 Mechanical Hotkeys ……………………………………………………………………………………………………………. 122 Wizards ……………………………………………………………………………………………………………………………. 122 The Mechanical Wizard ………………………………………………………………………………………………….. 123 Steps for Using the Application ……………………………………………………………………………………………….. 125 Create Analysis System ……………………………………………………………………………………………………….. 125 Define Engineering Data ……………………………………………………………………………………………………… 126 Attach Geometry ……………………………………………………………………………………………………………….. 126 Define Part Behavior …………………………………………………………………………………………………………… 129 Define Connections ……………………………………………………………………………………………………………. 132 Apply Mesh Controls and Preview Mesh …………………………………………………………………………………. 133 Establish Analysis Settings …………………………………………………………………………………………………… 134 Define Initial Conditions ………………………………………………………………………………………………………. 136 Applying Pre-Stress Effects for Implicit Analysis ……………………………………………………………………….. 138 Applying Pre-Stress Effects for Explicit Analysis ………………………………………………………………………… 140 Apply Loads and Supports …………………………………………………………………………………………………… 143 Solve ……………………………………………………………………………………………………………………………….. 145 Review Results …………………………………………………………………………………………………………………… 146

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Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

Mechanical User’s Guide Create Report (optional) ……………………………………………………………………………………………………… 147 Analysis Types ……………………………………………………………………………………………………………………….. 149 Design Assessment Analysis …………………………………………………………………………………………………. 149 Electric Analysis …………………………………………………………………………………………………………………. 152 Explicit Dynamics Analysis …………………………………………………………………………………………………… 155 Using Explicit Dynamics to Define Initial Conditions for Implicit Analysis …………………………………. 176 Linear Dynamic Analysis Types ……………………………………………………………………………………………… 179 Harmonic Response Analysis …………………………………………………………………………………………… 179 Harmonic Response (Full) Analysis Using Pre-Stressed Structural System …………………………………. 188 Harmonic Response Analysis Using Linked Modal Analysis System …………………………………………. 189 Linear Buckling Analysis …………………………………………………………………………………………………. 192 Modal Analysis …………………………………………………………………………………………………………….. 196 Random Vibration Analysis …………………………………………………………………………………………….. 202 Response Spectrum Analysis …………………………………………………………………………………………… 207 Magnetostatic Analysis ……………………………………………………………………………………………………….. 212 Rigid Dynamics Analysis ……………………………………………………………………………………………………… 216 Preparing a Rigid Dynamics Analysis ………………………………………………………………………………… 217 Command Reference for Rigid Dynamics Systems ……………………………………………………………….. 226 IronPython References ……………………………………………………………………………………………… 226 The Rigid Dynamics Object Model ………………………………………………………………………………. 226 Rigid Dynamics Command Objects Library …………………………………………………………………… 227 Command Use Examples ………………………………………………………………………………………….. 241 Screw Joint ………………………………………………………………………………………………………. 242 Constraint Equation …………………………………………………………………………………………… 242 Joint Condition: Initial Velocity ……………………………………………………………………………… 245 Joint Condition: Control Using Linear Feedback ……………………………………………………….. 245 Non-Linear Spring Damper ………………………………………………………………………………….. 247 Spherical Stop …………………………………………………………………………………………………… 248 Export of Joint Forces ………………………………………………………………………………………….. 250 Breakable Joint …………………………………………………………………………………………………. 252 Rigid Body Theory Guide ………………………………………………………………………………………………… 252 Degrees of freedom …………………………………………………………………………………………………. 253 Shape Functions ……………………………………………………………………………………………………… 257 Equations of Motion ………………………………………………………………………………………………… 259 Time Integration ……………………………………………………………………………………………………… 263 Geometric Correction and Stabilization ……………………………………………………………………….. 265 Contact and Stops …………………………………………………………………………………………………… 266 References …………………………………………………………………………………………………………….. 272 Static Structural Analysis ……………………………………………………………………………………………………… 272 Steady-State Thermal Analysis ………………………………………………………………………………………………. 277 Thermal-Electric Analysis …………………………………………………………………………………………………….. 281 Transient Structural Analysis ………………………………………………………………………………………………… 285 Transient Structural Analysis Using Linked Modal Analysis System ………………………………………………. 294 Transient Thermal Analysis …………………………………………………………………………………………………… 297 Special Analysis Topics ………………………………………………………………………………………………………… 301 Electromagnetics (EM) — Mechanical Data Transfer ………………………………………………………………. 302 Importing Data into a Thermal or Structural (Static or Transient) Analysis …………………………… 303 Importing Data into a Harmonic Analysis ……………………………………………………………………… 305 Exporting Results from a Thermal or Structural Analysis ………………………………………………….. 308 External Data Import ……………………………………………………………………………………………………… 310 External Data Export ……………………………………………………………………………………………………… 317 Fluid-Structure Interaction (FSI) ……………………………………………………………………………………….. 317 Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Mechanical User’s Guide One-Way Transfer FSI ……………………………………………………………………………………………….. 318 Two-Way Transfer FSI ……………………………………………………………………………………………….. 318 Using Imported Loads for One-Way FSI ………………………………………………………………………… 319 Face Forces at Fluid-Structure Interface ………………………………………………………………….. 321 Face Temperatures and Convections at Fluid-Structure Interface …………………………………. 321 Volumetric Temperature Transfer …………………………………………………………………………… 322 CFD Results Mapping ………………………………………………………………………………………….. 322 Icepak to Mechanical Data Transfer ………………………………………………………………………………….. 322 Mechanical-Electronics Interaction (Mechatronics) Data Transfer ……………………………………………. 324 Overall Workflow for Mechatronics Analysis ………………………………………………………………….. 324 Set up the Mechanical Application for Export to Simplorer ………………………………………………. 325 Polyflow to Mechanical Data Transfer ……………………………………………………………………………….. 325 Simplorer/Rigid Dynamics Co-Simulation …………………………………………………………………………. 327 Simplorer Pins ………………………………………………………………………………………………………… 329 Static Analysis From Rigid Dynamics Analysis …………………………………………………………………….. 330 Submodeling ……………………………………………………………………………………………………………….. 331 Understanding Submodeling …………………………………………………………………………………….. 332 Shell-to-Solid Submodels …………………………………………………………………………………….. 333 Nonlinear Submodeling ………………………………………………………………………………………. 334 Structural Submodeling Workflow ………………………………………………………………………………. 334 Thermal Submodeling Workflow ………………………………………………………………………………… 339 System Coupling ………………………………………………………………………………………………………….. 342 Supported Capabilities and Limitations ……………………………………………………………………….. 343 Variables Available for System Coupling ………………………………………………………………………. 344 System Coupling Related Settings in Mechanical …………………………………………………………… 345 Fluid-Structure Interaction (FSI) — One-Way Transfers Using System Coupling ………………………. 347 Thermal-Fluid-Structural Analyses using System Coupling ………………………………………………. 348 Restarting Structural Mechanical Analyses as Part of System Coupling ………………………………. 350 Generating Mechanical Restart Files ………………………………………………………………………. 350 Specifying a Restart Point in Mechanical …………………………………………………………………. 351 Making Changes in Mechanical Before Restarting …………………………………………………….. 351 Recovering the Mechanical Restart Point after a Workbench Crash ………………………………. 351 Running Mechanical as a System Coupling Participant from the Command Line ………………….. 352 Troubleshooting Two-Way Coupling Analysis Problems ………………………………………………….. 353 Product Licensing Considerations when using System Coupling ………………………………………. 353 Thermal-Stress Analysis ………………………………………………………………………………………………….. 354 One-way Acoustic Coupling Analysis ………………………………………………………………………………… 358 Rotordynamics Analysis …………………………………………………………………………………………………. 360 Fracture Analysis …………………………………………………………………………………………………………… 361 Fracture Analysis Workflows ………………………………………………………………………………………. 361 Limitations of Fracture Analysis ………………………………………………………………………………….. 363 Multi-Point Constraint (MPC) Contact for Fracture ………………………………………………………….. 363 Composite Analysis ……………………………………………………………………………………………………….. 364 Shell Modeling Workflow ………………………………………………………………………………………….. 364 Solid Modeling Workflow ………………………………………………………………………………………….. 366 Specifying Geometry ……………………………………………………………………………………………………………… 371 Geometry Basics ………………………………………………………………………………………………………………… 371 Multibody Behavior ………………………………………………………………………………………………………. 372 Working with Parts ……………………………………………………………………………………………………….. 372 Associativity ………………………………………………………………………………………………………………… 372 Integration Schemes ……………………………………………………………………………………………………… 373 Color Coding of Parts …………………………………………………………………………………………………….. 373

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Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

Mechanical User’s Guide Working with Bodies ……………………………………………………………………………………………………… 374 Hide or Suppress Bodies ………………………………………………………………………………………………… 375 Hide or Show Faces ……………………………………………………………………………………………………….. 375 Assumptions and Restrictions for Assemblies, Parts, and Bodies …………………………………………….. 376 Solid Bodies ………………………………………………………………………………………………………………………. 376 Surface Bodies …………………………………………………………………………………………………………………… 376 Assemblies of Surface Bodies ………………………………………………………………………………………….. 376 Thickness Mode ……………………………………………………………………………………………………………. 377 Importing Surface Body Models ………………………………………………………………………………………. 377 Importing Surface Body Thickness …………………………………………………………………………………… 378 Surface Body Shell Offsets ………………………………………………………………………………………………. 378 Specifying Surface Body Thickness …………………………………………………………………………………… 380 Specifying Surface Body Layered Sections …………………………………………………………………………. 383 Defining and Applying a Layered Section …………………………………………………………………….. 383 Viewing Individual Layers ………………………………………………………………………………………….. 384 Layered Section Properties ………………………………………………………………………………………… 385 Notes on Layered Section Behavior …………………………………………………………………………….. 385 Faces With Multiple Thicknesses and Layers Specified ………………………………………………………….. 386 Line Bodies ……………………………………………………………………………………………………………………….. 387 Mesh-Based Geometry ………………………………………………………………………………………………………… 388 CDB Import Element Types ……………………………………………………………………………………………… 397 Assembling Mechanical Models ……………………………………………………………………………………………. 398 Rigid Bodies ……………………………………………………………………………………………………………………… 401 2D Analyses ………………………………………………………………………………………………………………………. 402 Using Generalized Plane Strain ………………………………………………………………………………………… 404 Symmetry …………………………………………………………………………………………………………………………. 405 Types of Regions …………………………………………………………………………………………………………… 406 Symmetry Region ……………………………………………………………………………………………………. 407 Explicit Dynamics Symmetry ………………………………………………………………………………… 409 General Symmetry ………………………………………………………………………………………… 410 Global Symmetry Planes ………………………………………………………………………………… 410 Periodic Region ………………………………………………………………………………………………………. 411 Electromagnetic Periodic Symmetry ………………………………………………………………………. 411 Periodicity Example ………………………………………………………………………………………. 412 Cyclic Region ………………………………………………………………………………………………………….. 414 Cyclic Symmetry in a Static Structural Analysis …………………………………………………………. 416 Applying Loads and Supports for Cyclic Symmetry in a Static Structural Analysis ………. 416 Reviewing Results for Cyclic Symmetry in a Static Structural Analysis ……………………… 417 Cyclic Symmetry in a Modal Analysis ……………………………………………………………………… 418 Applying Loads and Supports for Cyclic Symmetry in a Modal Analysis …………………… 418 Analysis Settings for Cyclic Symmetry in a Modal Analysis …………………………………….. 419 Reviewing Results for Cyclic Symmetry in a Modal Analysis …………………………………… 419 Cyclic Symmetry in a Thermal Analysis ……………………………………………………………………. 425 Applying Loads for Cyclic Symmetry in a Thermal Analysis ……………………………………. 425 Reviewing Results for Cyclic Symmetry in a Thermal Analysis ………………………………… 425 Symmetry Defined in DesignModeler ……………………………………………………………………………….. 425 Symmetry in the Mechanical Application ………………………………………………………………………….. 426 Named Selections ………………………………………………………………………………………………………………. 429 Defining Named Selections …………………………………………………………………………………………….. 432 Specifying Named Selections by Geometry Type …………………………………………………………… 433 Specifying Named Selections using Worksheet Criteria …………………………………………………… 434 Promoting Scoped Objects to a Named Selection ……………………………………………………………….. 441 Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Mechanical User’s Guide Displaying Named Selections ………………………………………………………………………………………….. 442 Using Named Selections ………………………………………………………………………………………………… 446 Using Named Selections via the Toolbar ………………………………………………………………………. 446 Scoping Analysis Objects to Named Selections ……………………………………………………………… 448 Including Named Selections in Program Controlled Inflation ……………………………………………. 448 Importing Named Selections ……………………………………………………………………………………… 448 Exporting Named Selections ……………………………………………………………………………………… 449 Displaying Interior Mesh Faces ………………………………………………………………………………………… 449 Converting Named Selection Groups to Mechanical APDL Application Components …………………. 450 Mesh Numbering ……………………………………………………………………………………………………………….. 451 Path (Construction Geometry) ………………………………………………………………………………………………. 453 Surface (Construction Geometry) ………………………………………………………………………………………….. 459 Remote Point …………………………………………………………………………………………………………………….. 460 Specify a Remote Point ………………………………………………………………………………………………….. 461 Geometry Behaviors and Support Specifications ………………………………………………………………… 464 Remote Point Features …………………………………………………………………………………………………… 466 Point Mass ………………………………………………………………………………………………………………………… 468 Thermal Point Mass …………………………………………………………………………………………………………….. 469 Cracks ……………………………………………………………………………………………………………………………… 471 Defining a Pre-Meshed Crack ………………………………………………………………………………………….. 473 Interface Delamination and Contact Debonding ………………………………………………………………………. 474 Interface Delamination Application ………………………………………………………………………………….. 475 Contact Debonding Application ………………………………………………………………………………………. 478 Interface Delamination and ANSYS Composite PrepPost (ACP) ………………………………………………. 479 Gaskets ……………………………………………………………………………………………………………………………. 480 Gasket Bodies ………………………………………………………………………………………………………………. 481 Gasket Mesh Control ……………………………………………………………………………………………………… 481 Gasket Results ……………………………………………………………………………………………………………… 482 Setting Up Coordinate Systems ……………………………………………………………………………………………….. 483 Creating Coordinate Systems ……………………………………………………………………………………………….. 483 Initial Creation and Definition …………………………………………………………………………………………. 483 Establishing Origin for Associative and Non-Associative Coordinate Systems ……………………………. 484 Setting Principal Axis and Orientation ………………………………………………………………………………. 486 Using Transformations …………………………………………………………………………………………………… 487 Creating a Coordinate System Based on a Surface Normal …………………………………………………….. 487 Importing Coordinate Systems ……………………………………………………………………………………………… 488 Applying Coordinate Systems as Reference Locations ……………………………………………………………….. 488 Using Coordinate Systems to Specify Joint Locations ………………………………………………………………… 489 Creating Section Planes ………………………………………………………………………………………………………. 489 Create Construction Surface …………………………………………………………………………………………………. 491 Transferring Coordinate Systems to the Mechanical APDL Application …………………………………………. 492 Setting Connections ………………………………………………………………………………………………………………. 493 Connections Folder …………………………………………………………………………………………………………….. 493 Connections Worksheet ………………………………………………………………………………………………………. 494 Connection Group Folder …………………………………………………………………………………………………….. 497 Common Connections Folder Operations for Auto Generated Connections …………………………………… 501 Contact ……………………………………………………………………………………………………………………………. 503 Contact Overview …………………………………………………………………………………………………………. 503 Contact Formulation Theory …………………………………………………………………………………………… 504 Contact Settings …………………………………………………………………………………………………………… 506 Scope Settings ………………………………………………………………………………………………………… 507 Definition Settings …………………………………………………………………………………………………… 510

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Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

Mechanical User’s Guide Advanced Settings …………………………………………………………………………………………………… 515 Geometric Modification ……………………………………………………………………………………………. 525 Supported Contact Types ……………………………………………………………………………………………….. 528 Setting Contact Conditions Manually ……………………………………………………………………………….. 529 Contact Ease of Use Features …………………………………………………………………………………………… 530 Controlling Transparency for Contact Regions ………………………………………………………………. 530 Displaying Contact Bodies with Different Colors ……………………………………………………………. 530 Displaying Contact Bodies in Separate Windows ……………………………………………………………. 531 Hiding Bodies Not Scoped to a Contact Region ……………………………………………………………… 532 Renaming Contact Regions Based on Geometry Names ………………………………………………….. 532 Identifying Contact Regions for a Body ………………………………………………………………………… 533 Create Contact Debonding ……………………………………………………………………………………….. 533 Flipping Contact and Target Scope Settings ………………………………………………………………….. 533 Merging Contact Regions That Share Geometry …………………………………………………………….. 534 Saving or Loading Contact Region Settings ………………………………………………………………….. 534 Resetting Contact Regions to Default Settings ………………………………………………………………. 535 Locating Bodies Without Contact ……………………………………………………………………………….. 535 Locating Parts Without Contact ………………………………………………………………………………….. 535 Contact in Rigid Dynamics ……………………………………………………………………………………………… 535 Best Practices for Specifying Contact Conditions …………………………………………………………………. 538 Joints ………………………………………………………………………………………………………………………………. 542 Joint Characteristics ………………………………………………………………………………………………………. 542 Joint Types ………………………………………………………………………………………………………………….. 545 Joint Properties ……………………………………………………………………………………………………………. 553 Joint Stiffness ………………………………………………………………………………………………………………. 562 Manual Joint Creation ……………………………………………………………………………………………………. 564 Example: Assembling Joints ……………………………………………………………………………………………. 566 Example: Configuring Joints ……………………………………………………………………………………………. 576 Automatic Joint Creation ……………………………………………………………………………………………….. 589 Joint Stops and Locks …………………………………………………………………………………………………….. 590 Ease of Use Features ……………………………………………………………………………………………………… 594 Detecting Overconstrained Conditions ……………………………………………………………………………… 597 Mesh Connection ………………………………………………………………………………………………………………. 598 Springs …………………………………………………………………………………………………………………………….. 606 Beam Connections ……………………………………………………………………………………………………………… 614 Spot Welds ……………………………………………………………………………………………………………………….. 616 End Releases ……………………………………………………………………………………………………………………… 619 Body Interactions in Explicit Dynamics Analyses ………………………………………………………………………. 619 Properties for Body Interactions Folder ……………………………………………………………………………… 621 Contact Detection …………………………………………………………………………………………………… 621 Formulation ……………………………………………………………………………………………………………. 623 Shell Thickness Factor ………………………………………………………………………………………………. 624 Body Self Contact ……………………………………………………………………………………………………. 625 Element Self Contact ………………………………………………………………………………………………… 625 Tolerance ……………………………………………………………………………………………………………….. 625 Pinball Factor ………………………………………………………………………………………………………….. 626 Time Step Safety Factor …………………………………………………………………………………………….. 626 Limiting Time Step Velocity ……………………………………………………………………………………….. 626 Edge on Edge Contact ……………………………………………………………………………………………… 626 Interaction Type Properties for Body Interaction Object ……………………………………………………….. 627 Frictionless Type ……………………………………………………………………………………………………… 627 Frictional Type ………………………………………………………………………………………………………… 627 Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Mechanical User’s Guide Bonded Type ………………………………………………………………………………………………………….. 628 Reinforcement Type …………………………………………………………………………………………………. 630 Identifying Body Interactions Regions for a Body ………………………………………………………………… 632 Bearings …………………………………………………………………………………………………………………………… 632 Configuring Analysis Settings …………………………………………………………………………………………………. 635 Analysis Settings for Most Analysis Types ………………………………………………………………………………… 635 Step Controls ……………………………………………………………………………………………………………….. 635 Solver Controls …………………………………………………………………………………………………………….. 639 Restart Analysis ……………………………………………………………………………………………………………. 644 Restart Controls ……………………………………………………………………………………………………………. 644 Creep Controls ……………………………………………………………………………………………………………… 646 Cyclic Controls ……………………………………………………………………………………………………………… 646 Radiosity Controls …………………………………………………………………………………………………………. 647 Options for Analyses ……………………………………………………………………………………………………… 648 Damping Controls ………………………………………………………………………………………………………… 653 Nonlinear Controls ………………………………………………………………………………………………………… 655 Output Controls ……………………………………………………………………………………………………………. 658 Analysis Data Management …………………………………………………………………………………………….. 664 Rotordynamics Controls …………………………………………………………………………………………………. 666 Visibility ……………………………………………………………………………………………………………………… 666 Steps and Step Controls for Static and Transient Analyses ………………………………………………………….. 666 Role of Time in Tracking …………………………………………………………………………………………………. 667 Steps, Substeps, and Equilibrium Iterations ………………………………………………………………………… 667 Automatic Time Stepping ………………………………………………………………………………………………. 668 Guidelines for Integration Step Size ………………………………………………………………………………….. 669 Analysis Settings for Explicit Dynamics Analyses ………………………………………………………………………. 670 Explicit Dynamics Step Controls ………………………………………………………………………………………. 671 Explicit Dynamics Solver Controls …………………………………………………………………………………….. 675 Explicit Dynamics Euler Domain Controls ………………………………………………………………………….. 678 Explicit Dynamics Damping Controls ………………………………………………………………………………… 680 Explicit Dynamics Erosion Controls …………………………………………………………………………………… 681 Explicit Dynamics Output Controls …………………………………………………………………………………… 682 Explicit Dynamics Data Management Settings ……………………………………………………………………. 685 Recommendations for Analysis Settings in Explicit Dynamics ………………………………………………… 685 Explicit Dynamics Analysis Settings Notes …………………………………………………………………………. 689 Setting Up Boundary Conditions ……………………………………………………………………………………………… 691 Boundary Condition Scoping Method ……………………………………………………………………………………. 691 Types of Boundary Conditions ………………………………………………………………………………………………. 694 Inertial Type Boundary Conditions ……………………………………………………………………………………. 694 Acceleration …………………………………………………………………………………………………………… 694 Standard Earth Gravity ……………………………………………………………………………………………… 698 Rotational Velocity …………………………………………………………………………………………………… 700 Load Type Boundary Conditions ………………………………………………………………………………………. 703 Pressure ………………………………………………………………………………………………………………… 705 Pipe Pressure ………………………………………………………………………………………………………….. 708 Pipe Temperature ……………………………………………………………………………………………………. 710 Hydrostatic Pressure ………………………………………………………………………………………………… 712 Force …………………………………………………………………………………………………………………….. 716 Remote Force …………………………………………………………………………………………………………. 719 Bearing Load ………………………………………………………………………………………………………….. 723 Bolt Pretension ……………………………………………………………………………………………………….. 727 Moment ………………………………………………………………………………………………………………… 731

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Mechanical User’s Guide Generalized Plane Strain …………………………………………………………………………………………… 734 Line Pressure ………………………………………………………………………………………………………….. 737 PSD Base Excitation …………………………………………………………………………………………………. 740 RS Base Excitation ……………………………………………………………………………………………………. 741 Joint Load ………………………………………………………………………………………………………………. 742 Thermal Condition …………………………………………………………………………………………………… 744 Temperature …………………………………………………………………………………………………………… 747 Convection …………………………………………………………………………………………………………….. 749 Radiation ……………………………………………………………………………………………………………….. 753 Heat Flow ………………………………………………………………………………………………………………. 757 Heat Flux ……………………………………………………………………………………………………………….. 759 Internal Heat Generation …………………………………………………………………………………………… 762 Voltage ………………………………………………………………………………………………………………….. 764 Current ………………………………………………………………………………………………………………….. 766 Electromagnetic Boundary Conditions and Excitations …………………………………………………… 769 Magnetic Flux Boundary Conditions ………………………………………………………………………. 769 Conductor ………………………………………………………………………………………………………… 771 Solid Source Conductor Body ………………………………………………………………………….. 771 Voltage Excitation for Solid Source Conductors …………………………………………………… 773 Current Excitation for Solid Source Conductors …………………………………………………… 774 Stranded Source Conductor Body ……………………………………………………………………. 775 Current Excitation for Stranded Source Conductors …………………………………………….. 777 Motion Load …………………………………………………………………………………………………………… 779 Fluid Solid Interface …………………………………………………………………………………………………. 782 Detonation Point …………………………………………………………………………………………………….. 784 Support Type Boundary Conditions ………………………………………………………………………………….. 788 Fixed Supports ……………………………………………………………………………………………………….. 789 Displacements ………………………………………………………………………………………………………… 791 Remote Displacement ………………………………………………………………………………………………. 794 Velocity …………………………………………………………………………………………………………………. 798 Impedance Boundary ………………………………………………………………………………………………. 800 Frictionless Face ………………………………………………………………………………………………………. 803 Compression Only Support ……………………………………………………………………………………….. 805 Cylindrical Support ………………………………………………………………………………………………….. 808 Simply Supported ……………………………………………………………………………………………………. 809 Fixed Rotation ………………………………………………………………………………………………………… 811 Elastic Support ……………………………………………………………………………………………………….. 813 Conditions Type Boundary Conditions ………………………………………………………………………………. 815 Coupling ……………………………………………………………………………………………………………….. 815 Constraint Equation …………………………………………………………………………………………………. 817 Pipe Idealization ……………………………………………………………………………………………………… 819 Direct FE Type Boundary Conditions …………………………………………………………………………………. 822 Nodal Orientation ……………………………………………………………………………………………………. 822 Nodal Force ……………………………………………………………………………………………………………. 823 Nodal Pressure ………………………………………………………………………………………………………… 825 Nodal Displacement ………………………………………………………………………………………………… 827 Nodal Rotation ……………………………………………………………………………………………………….. 829 EM (Electro-Mechanical) Transducer ……………………………………………………………………………. 831 Remote Boundary Conditions …………………………………………………………………………………………. 833 Imported Boundary Conditions ……………………………………………………………………………………….. 834 Imported Body Force Density …………………………………………………………………………………….. 838 Imported Body Temperature ……………………………………………………………………………………… 839 Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Mechanical User’s Guide Imported Convection Coefficient ……………………………………………………………………………….. 840 Imported Displacement ……………………………………………………………………………………………. 840 Imported Force ……………………………………………………………………………………………………….. 841 Imported Heat Flux ………………………………………………………………………………………………….. 841 Imported Heat Generation ………………………………………………………………………………………… 841 Imported Initial Strain ………………………………………………………………………………………………. 842 Imported Initial Stress ………………………………………………………………………………………………. 843 Recommendations and Guidelines for Mapping of Initial Stress and Strain Data …………….. 844 Imported Pressure …………………………………………………………………………………………………… 845 Imported Remote Loads …………………………………………………………………………………………… 846 Imported Surface Force Density …………………………………………………………………………………. 846 Imported Temperature ……………………………………………………………………………………………… 846 Imported Velocity ……………………………………………………………………………………………………. 847 Spatial Varying Loads and Displacements ……………………………………………………………………………….. 847 Defining Boundary Condition Magnitude ……………………………………………………………………………….. 848 Using Results ………………………………………………………………………………………………………………………… 857 Introduction to the Use of Results …………………………………………………………………………………………. 857 Result Definitions ………………………………………………………………………………………………………………. 858 Applying Results Based on Geometry ……………………………………………………………………………….. 858 Scoping Results ……………………………………………………………………………………………………………. 861 Solution Coordinate System ……………………………………………………………………………………………. 863 Material Properties Used in Postprocessing ……………………………………………………………………….. 865 Clearing Results Data …………………………………………………………………………………………………….. 865 Averaged vs. Unaveraged Contour Results …………………………………………………………………………. 866 Peak Composite Results …………………………………………………………………………………………………. 874 Layered and Surface Body Results ……………………………………………………………………………………. 875 Unconverged Results …………………………………………………………………………………………………….. 876 Handling of Degenerate Elements ……………………………………………………………………………………. 877 Structural Results ……………………………………………………………………………………………………………….. 877 Deformation ………………………………………………………………………………………………………………… 879 Stress and Strain …………………………………………………………………………………………………………… 882 Equivalent (von Mises) ……………………………………………………………………………………………… 883 Maximum, Middle, and Minimum Principal …………………………………………………………………… 883 Maximum Shear ……………………………………………………………………………………………………… 884 Intensity ………………………………………………………………………………………………………………… 884 Vector Principals ……………………………………………………………………………………………………… 885 Error (Structural) ……………………………………………………………………………………………………… 885 Thermal Strain ………………………………………………………………………………………………………… 886 Equivalent Plastic Strain ……………………………………………………………………………………………. 887 Equivalent Creep Strain …………………………………………………………………………………………….. 888 Equivalent Total Strain ……………………………………………………………………………………………… 888 Membrane Stress …………………………………………………………………………………………………….. 888 Bending Stress ………………………………………………………………………………………………………… 889 Stabilization Energy ………………………………………………………………………………………………………. 889 Strain Energy ……………………………………………………………………………………………………………….. 890 Linearized Stress …………………………………………………………………………………………………………… 890 Damage Results ……………………………………………………………………………………………………………. 892 Contact Results …………………………………………………………………………………………………………….. 895 Frequency Response and Phase Response …………………………………………………………………………. 898 Stress Tools ………………………………………………………………………………………………………………….. 904 Maximum Equivalent Stress Safety Tool ………………………………………………………………………. 905 Maximum Shear Stress Safety Tool ……………………………………………………………………………… 907

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Mechanical User’s Guide Mohr-Coulomb Stress Safety Tool ……………………………………………………………………………….. 908 Maximum Tensile Stress Safety Tool …………………………………………………………………………….. 910 Fatigue (Fatigue Tool) …………………………………………………………………………………………………….. 912 Fracture Results ……………………………………………………………………………………………………………. 912 Fracture Tool …………………………………………………………………………………………………………… 915 Defining a Fracture Result …………………………………………………………………………………………. 915 Contact Tool ………………………………………………………………………………………………………………… 916 Contact Tool Initial Information ………………………………………………………………………………….. 920 Beam Tool ……………………………………………………………………………………………………………………. 922 Beam Results ……………………………………………………………………………………………………………….. 923 Shear-Moment Diagram ……………………………………………………………………………………………. 924 Structural Probes ………………………………………………………………………………………………………….. 926 Energy (Transient Structural and Rigid Dynamics Analyses) ……………………………………………… 936 Reactions: Forces and Moments …………………………………………………………………………………. 937 Joint Probes ……………………………………………………………………………………………………………. 944 Response PSD Probe ………………………………………………………………………………………………… 946 Spring Probes …………………………………………………………………………………………………………. 947 Bearing Probes ……………………………………………………………………………………………………….. 947 Beam Probes ………………………………………………………………………………………………………….. 948 Bolt Pretension Probes ……………………………………………………………………………………………… 948 Generalized Plain Strain Probes ………………………………………………………………………………….. 948 Gasket Results ……………………………………………………………………………………………………………… 948 Campbell Diagram Chart Results ……………………………………………………………………………………… 949 Thermal Results …………………………………………………………………………………………………………………. 952 Temperature ………………………………………………………………………………………………………………… 952 Heat Flux …………………………………………………………………………………………………………………….. 952 Heat Reaction ………………………………………………………………………………………………………………. 953 Error (Thermal) …………………………………………………………………………………………………………….. 953 Thermal Probes …………………………………………………………………………………………………………….. 953 Magnetostatic Results …………………………………………………………………………………………………………. 955 Electric Potential …………………………………………………………………………………………………………… 955 Total Magnetic Flux Density ……………………………………………………………………………………………. 955 Directional Magnetic Flux Density ……………………………………………………………………………………. 955 Total Magnetic Field Intensity ………………………………………………………………………………………….. 956 Directional Magnetic Field Intensity …………………………………………………………………………………. 956 Total Force …………………………………………………………………………………………………………………… 956 Directional Force ………………………………………………………………………………………………………….. 956 Current Density ……………………………………………………………………………………………………………. 956 Inductance ………………………………………………………………………………………………………………….. 956 Flux Linkage ………………………………………………………………………………………………………………… 957 Error (Magnetic) ……………………………………………………………………………………………………………. 958 Magnetostatic Probes ……………………………………………………………………………………………………. 958 Electric Results …………………………………………………………………………………………………………………… 960 Electric Probes ……………………………………………………………………………………………………………… 961 Fatigue Results ………………………………………………………………………………………………………………….. 961 Fatigue Material Properties …………………………………………………………………………………………….. 962 Fatigue Analysis and Loading Options ………………………………………………………………………………. 963 Reviewing Fatigue Results ………………………………………………………………………………………………. 966 User Defined Results …………………………………………………………………………………………………………… 970 Overview …………………………………………………………………………………………………………………….. 970 Characteristics ……………………………………………………………………………………………………………… 971 Application ………………………………………………………………………………………………………………….. 972 Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Mechanical User’s Guide Node-Based Scoping …………………………………………………………………………………………………….. 973 User Defined Result Expressions ………………………………………………………………………………………. 974 User Defined Result Identifier ………………………………………………………………………………………….. 977 Unit Description …………………………………………………………………………………………………………… 978 User Defined Results for the Mechanical APDL Solver ………………………………………………………….. 979 User Defined Results for Explicit Dynamics Analyses ……………………………………………………………. 983 Result Outputs …………………………………………………………………………………………………………………… 988 Chart and Table ……………………………………………………………………………………………………………. 988 Contour Results ……………………………………………………………………………………………………………. 991 Coordinate Systems Results ……………………………………………………………………………………………. 991 Nodal Coordinate Systems Results ………………………………………………………………………………. 991 Elemental Coordinate Systems Results ………………………………………………………………………… 992 Rotational Order of Coordinate System Results ……………………………………………………………… 993 Eroded Nodes in Explicit Dynamics Analyses ……………………………………………………………………… 993 Euler Domain in Explicit Dynamics Analyses ………………………………………………………………………. 995 Path Results …………………………………………………………………………………………………………………. 996 Probes ………………………………………………………………………………………………………………………. 1001 Overview and Probe Types ………………………………………………………………………………………. 1001 Probe Details View …………………………………………………………………………………………………. 1003 Surface Results …………………………………………………………………………………………………………… 1007 Vector Plots ……………………………………………………………………………………………………………….. 1010 Result Summary Worksheet …………………………………………………………………………………………… 1010 Result Utilities ………………………………………………………………………………………………………………….. 1011 Adaptive Convergence …………………………………………………………………………………………………. 1011 Animation …………………………………………………………………………………………………………………. 1011 Capped Isosurfaces ……………………………………………………………………………………………………… 1014 Dynamic Legend …………………………………………………………………………………………………………. 1015 Exporting Results ………………………………………………………………………………………………………… 1016 Generating Reports ……………………………………………………………………………………………………… 1017 Renaming Results Based on Definition ……………………………………………………………………………. 1017 Results Legend …………………………………………………………………………………………………………… 1017 Results Toolbar …………………………………………………………………………………………………………… 1019 Solution Combinations ………………………………………………………………………………………………… 1019 Understanding Solving …………………………………………………………………………………………………………. 1023 Solve Modes and Recommended Usage ……………………………………………………………………………….. 1025 Using Solve Process Settings ………………………………………………………………………………………………. 1027 Solution Restarts ………………………………………………………………………………………………………………. 1032 Solving Scenarios ……………………………………………………………………………………………………………… 1040 Solution Information Object ……………………………………………………………………………………………….. 1042 Postprocessing During Solve ………………………………………………………………………………………………. 1048 Result Trackers …………………………………………………………………………………………………………………. 1049 Structural Result Trackers ……………………………………………………………………………………………… 1051 Thermal Result Trackers ………………………………………………………………………………………………… 1053 Explicit Dynamics Result Trackers …………………………………………………………………………………… 1054 Point Scoped Result Trackers for Explicit Dynamics ………………………………………………………. 1054 Body Scoped Result Trackers for Explicit Dynamics ………………………………………………………. 1059 Force Reaction Result Trackers for Explicit Dynamics …………………………………………………….. 1063 Spring Result Trackers for Explicit Dynamics ……………………………………………………………….. 1064 Viewing and Filtering Result Tracker Graphs for Explicit Dynamics …………………………………… 1064 Adaptive Convergence ………………………………………………………………………………………………………. 1065 File Management in the Mechanical Application …………………………………………………………………….. 1070 Solving Units …………………………………………………………………………………………………………………… 1071

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Mechanical User’s Guide Saving your Results in the Mechanical Application ………………………………………………………………….. 1132 Writing and Reading the Mechanical APDL Application Files …………………………………………………….. 1133 Converting Boundary Conditions to Nodal DOF Constraints (Mechanical APDL Solver) ………………….. 1135 Resolving Thermal Boundary Condition Conflicts ……………………………………………………………………. 1136 Resume Capability for Explicit Dynamics Analyses ………………………………………………………………….. 1136 Solving a Fracture Analysis …………………………………………………………………………………………………. 1137 Commands Objects ………………………………………………………………………………………………………………. 1141 Commands Object Features ……………………………………………………………………………………………….. 1141 Using Commands Objects with the MAPDL Solver ………………………………………………………………….. 1145 Using Commands Objects with the Rigid Dynamics Solver ………………………………………………………. 1149 Setting Parameters ………………………………………………………………………………………………………………. 1151 Specifying Parameters ……………………………………………………………………………………………………….. 1151 CAD Parameters ……………………………………………………………………………………………………………….. 1153 Using Design Assessment ……………………………………………………………………………………………………… 1157 Predefined Assessment Types ……………………………………………………………………………………………… 1159 Modifying the Predefined Assessment Types Menu ……………………………………………………………. 1160 Using Advanced Combination Options with Design Assessment ………………………………………….. 1160 Introduction …………………………………………………………………………………………………………. 1161 Defining Results …………………………………………………………………………………………………….. 1161 Using BEAMST and FATJACK with Design Assessment ………………………………………………………… 1163 Using BEAMST with the Design Assessment System …………………………………………………………… 1163 Introduction …………………………………………………………………………………………………………. 1163 Information for Existing ASAS Users …………………………………………………………………………… 1164 Attribute Group Types …………………………………………………………………………………………….. 1166 Code of Practise Selection ………………………………………………………………………………….. 1167 General Text …………………………………………………………………………………………………….. 1168 Geometry Definition …………………………………………………………………………………………. 1168 Load Dependant Factors ……………………………………………………………………………………. 1169 Material Definition ……………………………………………………………………………………………. 1170 Ocean Environment ………………………………………………………………………………………….. 1171 Available Results ……………………………………………………………………………………………………. 1171 AISC LRFD Results …………………………………………………………………………………………….. 1171 AISC WSD Results ……………………………………………………………………………………………… 1172 API LRFD Results ………………………………………………………………………………………………. 1173 API WSD Results ……………………………………………………………………………………………….. 1176 BS5950 Results …………………………………………………………………………………………………. 1182 DS449 High Results …………………………………………………………………………………………… 1182 DS449 Normal Results ……………………………………………………………………………………….. 1185 ISO Results ………………………………………………………………………………………………………. 1186 NORSOK Results ……………………………………………………………………………………………….. 1189 NPD Results …………………………………………………………………………………………………….. 1192 Using FATJACK with the Design Assessment System ………………………………………………………….. 1195 Introduction …………………………………………………………………………………………………………. 1195 Information for Existing ASAS Users …………………………………………………………………………… 1196 Solution Selection Customization ……………………………………………………………………………… 1197 Attribute Group Types …………………………………………………………………………………………….. 1198 Analysis Type Selection ……………………………………………………………………………………… 1198 General Text …………………………………………………………………………………………………….. 1199 Geometry Definition …………………………………………………………………………………………. 1199 Joint Inspection Points ……………………………………………………………………………………… 1200 SCF Definitions ………………………………………………………………………………………………… 1200 Material Definition ……………………………………………………………………………………………. 1201 Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Mechanical User’s Guide Ocean Environment ………………………………………………………………………………………….. 1202 Available Results ……………………………………………………………………………………………………. 1202 Damage Values ………………………………………………………………………………………………… 1203 Fatigue Assessment ………………………………………………………………………………………….. 1204 SCF Values ………………………………………………………………………………………………………. 1204 Stress Histogram Results ……………………………………………………………………………………. 1204 Stress Range Results …………………………………………………………………………………………. 1205 Changing the Assessment Type or XML Definition File Contents ………………………………………………… 1206 Solution Selection …………………………………………………………………………………………………………….. 1207 The Solution Selection Table …………………………………………………………………………………………. 1207 Results Availability ………………………………………………………………………………………………………. 1208 Solution Combination Behavior ……………………………………………………………………………………… 1209 Using the Attribute Group Object ………………………………………………………………………………………… 1211 Developing and Debugging Design Assessment Scripts ………………………………………………………….. 1212 Using the DA Result Object ………………………………………………………………………………………………… 1213 The Design Assessment XML Definition File …………………………………………………………………………… 1214 Attributes Format ……………………………………………………………………………………………………….. 1215 Attribute Groups Format ………………………………………………………………………………………………. 1218 Script Format ……………………………………………………………………………………………………………… 1219 Results Format ……………………………………………………………………………………………………………. 1222 Design Assessment API Reference ……………………………………………………………………………………….. 1225 DesignAssessment class ……………………………………………………………………………………………….. 1232 Example Usage ……………………………………………………………………………………………………… 1233 Typical Evaluate (or Solve) Script Output …………………………………………………………………….. 1234 Helper class ……………………………………………………………………………………………………………….. 1234 Example Usage ……………………………………………………………………………………………………… 1235 Typical Evaluate (or Solve) Script Output …………………………………………………………………….. 1235 Typical Solver Output ……………………………………………………………………………………………… 1235 MeshData class …………………………………………………………………………………………………………… 1236 Example Usage ……………………………………………………………………………………………………… 1236 Typical Evaluate (or Solve) Script Output …………………………………………………………………….. 1237 DAElement class …………………………………………………………………………………………………………. 1237 Example Usage ……………………………………………………………………………………………………… 1239 Typical Evaluate (or Solve) Script Output …………………………………………………………………….. 1239 DANode class …………………………………………………………………………………………………………….. 1239 Example Usage ……………………………………………………………………………………………………… 1240 Typical Evaluate (or Solve) Script Output …………………………………………………………………….. 1240 SectionData class ………………………………………………………………………………………………………… 1240 Example Usage ……………………………………………………………………………………………………… 1241 Typical Evaluate (or Solve) Script Output …………………………………………………………………….. 1241 AttributeGroup class ……………………………………………………………………………………………………. 1242 Example Usage ……………………………………………………………………………………………………… 1242 Typical Evaluate (or Solve) Script Output …………………………………………………………………….. 1242 Attribute class …………………………………………………………………………………………………………….. 1243 Example Usage ……………………………………………………………………………………………………… 1243 Typical Evaluate (or Solve) Script Output …………………………………………………………………….. 1244 SolutionSelection class ………………………………………………………………………………………………… 1244 Example Usage ……………………………………………………………………………………………………… 1244 Typical Evaluate (or Solve) Script Output …………………………………………………………………….. 1244 Solution class ……………………………………………………………………………………………………………… 1245 Example Usage ……………………………………………………………………………………………………… 1248 Typical Evaluate (or Solve) Script Output …………………………………………………………………….. 1249

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Mechanical User’s Guide SolutionResult class …………………………………………………………………………………………………….. 1249 Example Usage ……………………………………………………………………………………………………… 1254 Typical Evaluate (or Solve) Script Output …………………………………………………………………….. 1254 DAResult class ……………………………………………………………………………………………………………. 1255 Example Usage ……………………………………………………………………………………………………… 1256 Typical Evaluate (or Solve) Script Output …………………………………………………………………….. 1257 DAResultSet class ………………………………………………………………………………………………………… 1257 Example Usage ……………………………………………………………………………………………………… 1258 Typical Evaluate (or Solve) Script Output …………………………………………………………………….. 1259 Examples of Design Assessment Usage …………………………………………………………………………………. 1259 Using Design Assessment to Obtain Results from Mechanical APDL ……………………………………… 1260 Creating the XML Definition File ……………………………………………………………………………….. 1260 Creating the Script to be Run on Solve, MAPDL_S.py ………………………………………………….. 1263 Creating the Script to be Run on Evaluate All Results, MAPDL_E.py ……………………………….. 1264 Expanding the Example ………………………………………………………………………………………….. 1265 Using Design Assessment to Calculate Complex Results, such as Those Required by ASME ………… 1266 Creating the XML Definition File ……………………………………………………………………………….. 1266 Creating the Script to be Run on Evaluate …………………………………………………………………… 1268 EvaluateAllResults …………………………………………………………………………………………….. 1268 EvaluateDamage ………………………………………………………………………………………………. 1268 EvaluateCulmativeDamage ………………………………………………………………………………… 1269 Plot ……………………………………………………………………………………………………………….. 1269 Using Design Assessment to Perform Further Results Analysis for an Explicit Dynamics Analysis …. 1270 Creating the XML Definition File ……………………………………………………………………………….. 1270 Creating the Script to be Run on Evaluate …………………………………………………………………… 1272 Expanding the Example ………………………………………………………………………………………….. 1273 Using Design Assessment to Obtain Composite Results Using Mechanical APDL …………………….. 1273 Creating the XML Definition File ……………………………………………………………………………….. 1275 Creating the Script to be Run on Solve, SolveFailure.py ………………………………………… 1277 Creating the Script to be Run on Evaluate All Results, EvaluateFailure.py ………………… 1277 Using a Dictionary to Avoid a Long if/elif/else Statement. …………………………………………. 1277 Writing the MADPL .inp File from Within Design Assessment …………………………………. 1278 Running Mechanical APDL Multiple Times …………………………………………………………….. 1278 Expanding the Example ………………………………………………………………………………………….. 1279 Using Design Assessment to Access and Present Multiple Step Results ………………………………….. 1279 Creating the XML Definition File ……………………………………………………………………………….. 1279 Creating the Script to be Run on Evaluate …………………………………………………………………… 1280 Using Design Assessment to Perform an Explicit-to-Implicit Sequential Analysis ……………………… 1281 Creating the XML Definition File ……………………………………………………………………………….. 1281 Creating the Solve Script …………………………………………………………………………………………. 1281 Productivity Tools ………………………………………………………………………………………………………………… 1287 Generating Multiple Objects from a Template Object ………………………………………………………………. 1287 Tagging Objects ……………………………………………………………………………………………………………….. 1292 Creating Tags ……………………………………………………………………………………………………………… 1292 Applying Tags to Objects ………………………………………………………………………………………………. 1292 Deleting a Tag …………………………………………………………………………………………………………….. 1293 Renaming a Tag ………………………………………………………………………………………………………….. 1293 Highlighting Tagged Tree Objects …………………………………………………………………………………… 1293 Objects Reference ………………………………………………………………………………………………………………… 1295 Alert ………………………………………………………………………………………………………………………………. 1297 Analysis Settings ………………………………………………………………………………………………………………. 1298 Angular Velocity ……………………………………………………………………………………………………………….. 1299 Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Mechanical User’s Guide Beam ……………………………………………………………………………………………………………………………… 1300 Body ………………………………………………………………………………………………………………………………. 1302 Body Interactions ……………………………………………………………………………………………………………… 1304 Body Interaction ………………………………………………………………………………………………………………. 1306 Chart ……………………………………………………………………………………………………………………………… 1307 Commands ……………………………………………………………………………………………………………………… 1307 Comment ……………………………………………………………………………………………………………………….. 1309 Connections ……………………………………………………………………………………………………………………. 1309 Connection Group ……………………………………………………………………………………………………………. 1311 Construction Geometry …………………………………………………………………………………………………….. 1313 Contact Debonding ………………………………………………………………………………………………………….. 1313 Contact Region ………………………………………………………………………………………………………………… 1314 Object Properties — Most Structural Analyses …………………………………………………………………….. 1316 Object Properties — Explicit Dynamics Analyses …………………………………………………………………. 1317 Object Properties — Thermal and Electromagnetic Analyses …………………………………………………. 1317 Object Properties — Rigid Body Dynamics Analyses …………………………………………………………….. 1318 Contact Tool (Group) …………………………………………………………………………………………………………. 1318 Convergence …………………………………………………………………………………………………………………… 1320 Coordinate System ……………………………………………………………………………………………………………. 1321 Coordinate Systems ………………………………………………………………………………………………………….. 1324 Crack ……………………………………………………………………………………………………………………………… 1325 Direct FE (Group) ……………………………………………………………………………………………………………… 1327 End Release …………………………………………………………………………………………………………………….. 1328 Environment (Group) ………………………………………………………………………………………………………… 1329 Fatigue Tool (Group) …………………………………………………………………………………………………………. 1330 Figure …………………………………………………………………………………………………………………………….. 1333 Fluid Surface ……………………………………………………………………………………………………………………. 1334 Fracture ………………………………………………………………………………………………………………………….. 1335 Gasket Mesh Control …………………………………………………………………………………………………………. 1336 Geometry ……………………………………………………………………………………………………………………….. 1336 Global Coordinate System ………………………………………………………………………………………………….. 1339 Image …………………………………………………………………………………………………………………………….. 1340 Imported Layered Section ………………………………………………………………………………………………….. 1340 Imported Load (Group) ……………………………………………………………………………………………………… 1342 Imported Remote Loads …………………………………………………………………………………………………….. 1343 Imported Thickness ………………………………………………………………………………………………………….. 1345 Imported Thickness (Group) ……………………………………………………………………………………………….. 1347 Initial Conditions ………………………………………………………………………………………………………………. 1348 Initial Temperature ……………………………………………………………………………………………………………. 1349 Interface Delamination ……………………………………………………………………………………………………… 1350 Joint ………………………………………………………………………………………………………………………………. 1353 Layered Section ……………………………………………………………………………………………………………….. 1354 Loads, Supports, and Conditions (Group) ………………………………………………………………………………. 1355 Mesh ……………………………………………………………………………………………………………………………… 1357 Mesh Connection ……………………………………………………………………………………………………………… 1359 Mesh Control Tools (Group) ………………………………………………………………………………………………… 1361 Mesh Group (Group) …………………………………………………………………………………………………………. 1363 Mesh Grouping ………………………………………………………………………………………………………………… 1364 Mesh Numbering ……………………………………………………………………………………………………………… 1364 Modal …………………………………………………………………………………………………………………………….. 1365 Model …………………………………………………………………………………………………………………………….. 1366 Named Selections …………………………………………………………………………………………………………….. 1367

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Mechanical User’s Guide Numbering Control …………………………………………………………………………………………………………… 1370 Part ……………………………………………………………………………………………………………………………….. 1371 Path ……………………………………………………………………………………………………………………………….. 1372 Periodic/Cyclic Region ……………………………………………………………………………………………………….. 1373 Point Mass ………………………………………………………………………………………………………………………. 1375 Pre-Meshed Crack …………………………………………………………………………………………………………….. 1376 Pre-Stress ……………………………………………………………………………………………………………………….. 1377 Probe …………………………………………………………………………………………………………………………….. 1379 Project ……………………………………………………………………………………………………………………………. 1380 Remote Point …………………………………………………………………………………………………………………… 1381 Remote Points …………………………………………………………………………………………………………………. 1383 Result Tracker ………………………………………………………………………………………………………………….. 1383 Results and Result Tools (Group) ………………………………………………………………………………………….. 1385 Solution ………………………………………………………………………………………………………………………….. 1389 Solution Combination ……………………………………………………………………………………………………….. 1390 Solution Information …………………………………………………………………………………………………………. 1391 Spot Weld ……………………………………………………………………………………………………………………….. 1391 Spring ……………………………………………………………………………………………………………………………. 1393 Stress Tool (Group) ……………………………………………………………………………………………………………. 1395 Surface …………………………………………………………………………………………………………………………… 1397 Symmetry ……………………………………………………………………………………………………………………….. 1397 Symmetry Region …………………………………………………………………………………………………………….. 1398 Thermal Point Mass …………………………………………………………………………………………………………… 1399 Thickness ………………………………………………………………………………………………………………………… 1401 Validation ……………………………………………………………………………………………………………………….. 1402 Velocity ………………………………………………………………………………………………………………………….. 1404 Virtual Body …………………………………………………………………………………………………………………….. 1405 Virtual Body Group …………………………………………………………………………………………………………… 1407 Virtual Cell ………………………………………………………………………………………………………………………. 1407 Virtual Hard Vertex ……………………………………………………………………………………………………………. 1408 Virtual Split Edge ……………………………………………………………………………………………………………… 1409 Virtual Split Face ………………………………………………………………………………………………………………. 1410 Virtual Topology ………………………………………………………………………………………………………………. 1410 CAD System Information ………………………………………………………………………………………………………. 1413 General Information ………………………………………………………………………………………………………….. 1414 Troubleshooting ………………………………………………………………………………………………………………….. 1415 General Product Limitations ……………………………………………………………………………………………….. 1415 Problem Situations ……………………………………………………………………………………………………………. 1415 A Linearized Stress Result Cannot Be Solved. ……………………………………………………………………. 1416 A Load Transfer Error Has Occurred. ………………………………………………………………………………… 1417 Although the Exported File Was Saved to Disk ………………………………………………………………….. 1417 Although the Solution Failed to Solve Completely at all Time Points. …………………………………….. 1417 An Error Occurred Inside the SOLVER Module: Invalid Material Properties ………………………………. 1418 An Error Occurred While Solving Due To Insufficient Disk Space …………………………………………… 1419 An Error Occurred While Starting the Solver Module ………………………………………………………….. 1419 An Internal Solution Magnitude Limit Was Exceeded. …………………………………………………………. 1420 An Iterative Solver Was Used for this Analysis ……………………………………………………………………. 1420 At Least One Body Has Been Found to Have Only 1 Element ………………………………………………… 1420 At Least One Spring Exists with Incorrectly Defined Nonlinear Stiffness …………………………………. 1421 Animation Does not Export Correctly ……………………………………………………………………………… 1421 Application Not Closing as Expected ………………………………………………………………………………. 1422 Assemblies Missing Parts ……………………………………………………………………………………………… 1422 Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Mechanical User’s Guide CATIA V5 and IGES Surface Bodies ………………………………………………………………………………….. 1422 Constraint Equations Were Not Properly Matched ……………………………………………………………… 1422 Error Inertia tensor is too large ………………………………………………………………………………………. 1422 Failed to Load Microsoft Office Application ………………………………………………………………………. 1422 Illogical Reaction Results ………………………………………………………………………………………………. 1422 Large Deformation Effects are Active ………………………………………………………………………………. 1423 MPC equations were not built for one or more contact regions or remote boundary conditions …. 1423 One or More Contact Regions May Not Be In Initial Contact …………………………………………………. 1423 One or more MPC contact regions or remote boundary conditions may have conflicts …………….. 1424 One or More Parts May Be Underconstrained ……………………………………………………………………. 1424 One or More Remote Boundary Conditions is Scoped to a Large Number of Elements ……………… 1425 Problems Unique to Background (Asynchronous) Solutions ………………………………………………… 1425 Problems Using Solution ………………………………………………………………………………………………. 1426 Running Norton AntiVirusTM Causes the Mechanical Application to Crash ……………………………… 1427 The Correctly Licensed Product Will Not Run …………………………………………………………………….. 1427 The Deformation is Large Compared to the Model Bounding Box …………………………………………. 1428 The Initial Time Increment May Be Too Large for This Problem ……………………………………………… 1428 The Joint Probe cannot Evaluate Results ………………………………………………………………………….. 1429 The License Manager Server Is Down ………………………………………………………………………………. 1429 Linux Platform — Localized Operating System ……………………………………………………………………. 1429 The Low/High Boundaries of Cyclic Symmetry …………………………………………………………………. 1430 The Remote Boundary Condition object is defined on the Cyclic Axis of Symmetry ………………….. 1430 The Solution Combination Folder …………………………………………………………………………………… 1430 The Solver Engine was Unable to Converge ……………………………………………………………………… 1431 The Solver Has Found Conflicting DOF Constraints ……………………………………………………………. 1432 Problem with RSM-Mechanical Connection ……………………………………………………………………… 1432 Unable to Find Requested Modes …………………………………………………………………………………… 1432 You Must Specify Joint Conditions to all Three Rotational DOFs ……………………………………………. 1433 Recommendations ……………………………………………………………………………………………………………. 1433 A. Glossary of General Terms …………………………………………………………………………………………………….. 1435 B. Tutorials ……………………………………………………………………………………………………………………………. 1439 Steady-State and Transient Thermal Analysis of a Circuit Board ………………………………………………….. 1439 Cyclic Symmetry Analysis of a Rotor — Brake Assembly ……………………………………………………………… 1449 Using Finite Element Access to Resolve Overconstraint ……………………………………………………………. 1464 Actuator Mechanism using Rigid Body Dynamics …………………………………………………………………… 1495 Track Roller Mechanism using Point on Curve Joints and Rigid Body Dynamics ……………………………. 1504 Simple Pendulum using Rigid Dynamics and Nonlinear Bushing ……………………………………………….. 1510 Fracture Analysis of a Double Cantilever Beam (DCB) using Pre-Meshed Crack ……………………………… 1515 Fracture Analysis of an X-Joint Problem with Surface Flaw using Internally Generated Crack Mesh …… 1522 Fracture Analysis of a 2D Cracked Specimen using Pre-Meshed Crack …………………………………………. 1528 Interface Delamination Analysis of Double Cantilever Beam ……………………………………………………… 1536 Delamination Analysis using Contact Based Debonding Capability ……………………………………………. 1555 Nonlinear Static Structural Analysis of a Rubber Boot Seal ………………………………………………………… 1569 C. Data Transfer Mesh Mapping ………………………………………………………………………………………………… 1595 Mapping Validation …………………………………………………………………………………………………………… 1612 D. LS-DYNA Keywords Used in an Explicit Dynamics Analysis ………………………………………………………….. 1617 Supported LS-DYNA Keywords ……………………………………………………………………………………………. 1617 LS-DYNA General Descriptions ……………………………………………………………………………………………. 1646 E. Workbench Mechanical Wizard Advanced Programming Topics …………………………………………………… 1649 Overview ………………………………………………………………………………………………………………………… 1649 URI Address and Path Considerations …………………………………………………………………………………… 1650 Using Strings and Languages ……………………………………………………………………………………………… 1651

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Mechanical User’s Guide Guidelines for Editing XML Files …………………………………………………………………………………………… 1652 About the TaskML Merge Process ………………………………………………………………………………………… 1652 Using the Integrated Wizard Development Kit (WDK) ………………………………………………………………. 1653 Using IFRAME Elements …………………………………………………………………………………………………….. 1653 TaskML Reference …………………………………………………………………………………………………………….. 1654 Overview Map of TaskML ………………………………………………………………………………………………. 1654 Document Element ……………………………………………………………………………………………………… 1655 simulation-wizard ………………………………………………………………………………………………….. 1655 External References ……………………………………………………………………………………………………… 1656 Merge ………………………………………………………………………………………………………………….. 1656 Script …………………………………………………………………………………………………………………… 1656 Object Grouping …………………………………………………………………………………………………………. 1657 object-group ………………………………………………………………………………………………………… 1657 object-groups ……………………………………………………………………………………………………….. 1658 object-type …………………………………………………………………………………………………………… 1658 Status Definitions ………………………………………………………………………………………………………… 1659 status ………………………………………………………………………………………………………………….. 1659 statuses ……………………………………………………………………………………………………………….. 1660 Language and Text ………………………………………………………………………………………………………. 1660 data …………………………………………………………………………………………………………………….. 1660 language ……………………………………………………………………………………………………………… 1660 string …………………………………………………………………………………………………………………… 1661 strings …………………………………………………………………………………………………………………. 1661 Tasks and Events …………………………………………………………………………………………………………. 1662 activate-event ……………………………………………………………………………………………………….. 1662 task …………………………………………………………………………………………………………………….. 1663 tasks ……………………………………………………………………………………………………………………. 1663 update-event ………………………………………………………………………………………………………… 1664 Wizard Content …………………………………………………………………………………………………………… 1664 body ……………………………………………………………………………………………………………………. 1664 group ………………………………………………………………………………………………………………….. 1665 iframe ………………………………………………………………………………………………………………….. 1666 taskref …………………………………………………………………………………………………………………. 1666 Rules ………………………………………………………………………………………………………………………… 1667 Statements …………………………………………………………………………………………………………… 1667 and ………………………………………………………………………………………………………………… 1667 debug ……………………………………………………………………………………………………………. 1667 if then else stop ……………………………………………………………………………………………….. 1668 not ………………………………………………………………………………………………………………… 1669 or ………………………………………………………………………………………………………………….. 1669 update …………………………………………………………………………………………………………… 1669 Conditions ……………………………………………………………………………………………………………. 1670 assembly-geometry ………………………………………………………………………………………….. 1670 changeable-length-unit ……………………………………………………………………………………. 1670 geometry-includes-sheets ………………………………………………………………………………….. 1670 level ………………………………………………………………………………………………………………. 1671 object …………………………………………………………………………………………………………….. 1671 zero-thickness-sheet …………………………………………………………………………………………. 1672 valid-emag-geometry ……………………………………………………………………………………….. 1673 enclosure-exists ……………………………………………………………………………………………….. 1673 Actions ………………………………………………………………………………………………………………… 1673 click-button …………………………………………………………………………………………………….. 1674 Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Mechanical User’s Guide display-details-callout ……………………………………………………………………………………….. 1674 display-help-topic …………………………………………………………………………………………….. 1675 display-outline-callout ………………………………………………………………………………………. 1675 display-status-callout ………………………………………………………………………………………… 1676 display-tab-callout ……………………………………………………………………………………………. 1676 display-task-callout …………………………………………………………………………………………… 1677 display-toolbar-callout ………………………………………………………………………………………. 1677 open-url …………………………………………………………………………………………………………. 1678 select-all-objects ………………………………………………………………………………………………. 1679 select-field ………………………………………………………………………………………………………. 1680 select-first-object ……………………………………………………………………………………………… 1680 select-first-parameter-field …………………………………………………………………………………. 1681 select-first-undefined-field …………………………………………………………………………………. 1682 select-zero-thickness-sheets ………………………………………………………………………………. 1682 select-enclosures ……………………………………………………………………………………………… 1682 send-mail ……………………………………………………………………………………………………….. 1682 set-caption ……………………………………………………………………………………………………… 1683 set-icon ………………………………………………………………………………………………………….. 1684 set-status ………………………………………………………………………………………………………… 1684 Scripting ……………………………………………………………………………………………………………………. 1685 eval …………………………………………………………………………………………………………………….. 1685 Standard Object Groups Reference ………………………………………………………………………………………. 1686 Tutorials …………………………………………………………………………………………………………………………. 1689 Tutorial: Adding a Link ………………………………………………………………………………………………….. 1689 Tutorial: Creating a Custom Task …………………………………………………………………………………….. 1691 Tutorial: Creating a Custom Wizard …………………………………………………………………………………. 1692 Tutorial: Adding a Web Search IFRAME …………………………………………………………………………….. 1693 Completed TaskML Files ……………………………………………………………………………………………….. 1695 Links.xml ……………………………………………………………………………………………………………… 1695 Insert100psi.xml ……………………………………………………………………………………………………. 1695 CustomWizard.xml …………………………………………………………………………………………………. 1696 Search.htm …………………………………………………………………………………………………………… 1697 CustomWizardSearch.xml ……………………………………………………………………………………….. 1698 Wizard Development Kit (WDK) Groups ………………………………………………………………………………… 1699 WDK: Tools Group ……………………………………………………………………………………………………….. 1699 WDK: Commands Group ……………………………………………………………………………………………….. 1700 WDK Tests: Actions ………………………………………………………………………………………………………. 1701 WDK Tests: Flags (Conditions) ………………………………………………………………………………………… 1701 F. Material Models Used in Explicit Dynamics Analysis …………………………………………………………………… 1703 Introduction ……………………………………………………………………………………………………………………. 1703 Explicit Material Library ……………………………………………………………………………………………………… 1705 Density …………………………………………………………………………………………………………………………… 1711 Linear Elastic ……………………………………………………………………………………………………………………. 1711 Isotropic Elasticity ……………………………………………………………………………………………………….. 1711 Orthotropic Elasticity …………………………………………………………………………………………………… 1712 Viscoelastic ………………………………………………………………………………………………………………… 1712 Test Data ………………………………………………………………………………………………………………………… 1713 Hyperelasticity …………………………………………………………………………………………………………………. 1713 Plasticity …………………………………………………………………………………………………………………………. 1719 Bilinear Isotropic Hardening ………………………………………………………………………………………….. 1719 Multilinear Isotropic Hardening ……………………………………………………………………………………… 1720 Bilinear Kinematic Hardening ………………………………………………………………………………………… 1720

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Mechanical User’s Guide Multilinear Kinematic Hardening ……………………………………………………………………………………. 1720 Johnson-Cook Strength ……………………………………………………………………………………………….. 1721 Cowper-Symonds Strength …………………………………………………………………………………………… 1723 Steinberg-Guinan Strength …………………………………………………………………………………………… 1724 Zerilli-Armstrong Strength ……………………………………………………………………………………………. 1725 Brittle/Granular ………………………………………………………………………………………………………………… 1727 Drucker-Prager Strength Linear ……………………………………………………………………………………… 1727 Drucker-Prager Strength Stassi ………………………………………………………………………………………. 1728 Drucker-Prager Strength Piecewise ………………………………………………………………………………… 1729 Johnson-Holmquist Strength Continuous ………………………………………………………………………… 1730 Johnson-Holmquist Strength Segmented ………………………………………………………………………… 1732 RHT Concrete Strength …………………………………………………………………………………………………. 1734 MO Granular ………………………………………………………………………………………………………………. 1740 Equations of State …………………………………………………………………………………………………………….. 1741 Background ……………………………………………………………………………………………………………….. 1741 Bulk Modulus ……………………………………………………………………………………………………………… 1742 Shear Modulus ……………………………………………………………………………………………………………. 1742 Ideal Gas EOS ……………………………………………………………………………………………………………… 1742 Polynomial EOS ………………………………………………………………………………………………………….. 1743 Shock EOS Linear ………………………………………………………………………………………………………… 1745 Shock EOS Bilinear ………………………………………………………………………………………………………. 1746 JWL EOS ……………………………………………………………………………………………………………………. 1748 Porosity ………………………………………………………………………………………………………………………….. 1750 Porosity-Crushable Foam ……………………………………………………………………………………………… 1750 Compaction EOS Linear ……………………………………………………………………………………………….. 1753 Compaction EOS Non-Linear …………………………………………………………………………………………. 1754 P-alpha EOS ……………………………………………………………………………………………………………….. 1756 Failure ……………………………………………………………………………………………………………………………. 1759 Plastic Strain Failure …………………………………………………………………………………………………….. 1760 Principal Stress Failure ………………………………………………………………………………………………….. 1760 Principal Strain Failure ………………………………………………………………………………………………….. 1761 Stochastic Failure ………………………………………………………………………………………………………… 1762 Tensile Pressure Failure ………………………………………………………………………………………………… 1764 Crack Softening Failure ………………………………………………………………………………………………… 1764 Johnson-Cook Failure …………………………………………………………………………………………………… 1767 Grady Spall Failure ………………………………………………………………………………………………………. 1768 Strength …………………………………………………………………………………………………………………………. 1769 Thermal Specific Heat ……………………………………………………………………………………………………….. 1769 Rigid Materials …………………………………………………………………………………………………………………. 1770 G. Explicit Dynamics Theory Guide …………………………………………………………………………………………….. 1771 Why use Explicit Dynamics? ……………………………………………………………………………………………….. 1771 What is Explicit Dynamics? …………………………………………………………………………………………………. 1771 The Solution Strategy …………………………………………………………………………………………………… 1772 Basic Formulations ………………………………………………………………………………………………………. 1772 Implicit Transient Dynamics …………………………………………………………………………………….. 1773 Explicit Transient Dynamics ……………………………………………………………………………………… 1773 Time Integration …………………………………………………………………………………………………………. 1774 Implicit Time Integration …………………………………………………………………………………………. 1774 Explicit Time Integration …………………………………………………………………………………………. 1774 Mass Scaling …………………………………………………………………………………………………………. 1776 Wave Propagation ……………………………………………………………………………………………………….. 1777 Elastic Waves ………………………………………………………………………………………………………… 1777 Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Mechanical User’s Guide Plastic Waves ………………………………………………………………………………………………………… 1777 Shock Waves …………………………………………………………………………………………………………. 1778 Reference Frame …………………………………………………………………………………………………………. 1779 Lagrangian and Eulerian Reference Frames …………………………………………………………………. 1779 Eulerian (Virtual) Reference Frame in Explicit Dynamics ………………………………………………… 1780 Post-Processing a Body with Reference Frame Euler (Virtual) ………………………………………….. 1782 Key Concepts of Euler (Virtual) Solutions ……………………………………………………………………. 1783 Multiple Material Stress States …………………………………………………………………………….. 1784 Multiple Material Transport ………………………………………………………………………………… 1786 Supported Material Properties ……………………………………………………………………………. 1786 Known Limitations of Euler Solutions …………………………………………………………………… 1786 Explicit Fluid Structure Interaction (Euler-Lagrange Coupling) ……………………………………………… 1786 Shell Coupling ………………………………………………………………………………………………………. 1788 Sub-cycling …………………………………………………………………………………………………………… 1788 Analysis Settings ………………………………………………………………………………………………………………. 1789 Step Controls ……………………………………………………………………………………………………………… 1789 Damping Controls ……………………………………………………………………………………………………….. 1790 Solver Controls …………………………………………………………………………………………………………… 1794 Erosion Controls …………………………………………………………………………………………………………. 1802 Remote Points in Explicit Dynamics ……………………………………………………………………………………… 1803 Explicit Dynamics Remote Points ……………………………………………………………………………………. 1803 Explicit Dynamics Remote Boundary Conditions ……………………………………………………………….. 1804 References ………………………………………………………………………………………………………………………. 1804 H. Content to be provided ……………………………………………………………………………………………………….. 1807 Introduction ……………………………………………………………………………………………………………………. 1807 Index …………………………………………………………………………………………………………………………………… 1809

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Overview ANSYS Mechanical is a Workbench application that can perform a variety of engineering simulations, including stress, thermal, vibration, thermo-electric, and magnetostatic simulations. A typical simulation consists of setting up the model and the loads applied to it, solving for the model’s response to the loads, then examining the details of the response with a variety of tools. The Mechanical application has «objects» arranged in a tree structure that guide you through the different steps of a simulation. By expanding the objects, you expose the details associated with the object, and you can use the corresponding tools and specification tables to perform that part of the simulation. Objects are used, for example, to define environmental conditions such as contact surfaces and loadings, and to define the types of results you want to have available for review. The following Help topics describe in detail how to use the Mechanical application to set up and run a simulation: • Application Interface • Steps for Using the Application • Analysis Types • Specifying Geometry • Setting Up Coordinate Systems • Setting Connections • Configuring Analysis Settings • Setting Up Boundary Conditions • Using Results • Understanding Solving • Commands Objects • Setting Parameters

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Mechanical Application Interface This section describes the elements of the Mechanical Application interface, their purpose and conditions, as well as the methods for their use. The following topics are covered in this section: Mechanical Application Window Windows Management Main Windows Contextual Windows Main Menus Toolbars Interface Behavior Based on License Levels Environment Filtering Customizing the Mechanical Application Working with Graphics Mechanical Hotkeys Wizards

Mechanical Application Window The functional elements of the interface include the following. Window Component

Description

Main Menus (p. 44)

This menu includes the basic menus such as File and Edit.

Standard Toolbar (p. 49)

This toolbar contains commonly used application commands.

Graphics Toolbar (p. 50)

This toolbar contains commands that control pointer mode or cause an action in the graphics browser.

Context Toolbar (p. 53)

This toolbar contains task-specific commands that change depending on where you are in the Tree Outline (p. 3).

Unit Conversion Toolbar (p. 69)

Not visible by default. This toolbar allows you to convert units for various properties.

Named Selection Toolbar (p. 69)

Not visible by default. This toolbar contains options to manage named selections.

Graphics Options Toolbar (p. 69)

This toolbar provides access to general graphics controls such as wireframe and mesh visibility.

Edge Graphics Options (p. 71)

This toolbar provides access to graphics features pertaining to edge display, such as the ability to distinguish mesh connectivity.

Tree Outline (p. 3)

Outline view of the simulation project. Always visible. Location in the outline sets the context for other controls. Provides access to object’s context menus. Allows renaming of objects. Establishes what details display in the Details View (p. 11).

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Application Interface Window Component

Description

Details View (p. 11)

The Details View (p. 11) corresponds to the Outline selection. Displays a details window on the lower left panel of the Mechanical application window which contains details about each object in the Outline.

Geometry Window (p. 20)

Displays and manipulates the visual representation of the object selected in the Outline. This window displays: • 3D Geometry • 2D/3D Graph • Spreadsheet • HTML Pages

Note The Geometry window may include splitter bars for dividing views. Reference Help

Opens an objects reference help page for the highlighted object.

Status Bar

Brief in-context tip. Selection feedback.

Splitter Bar

Application window has up to three splitter bars.

Windows Management The Mechanical window contains window panes that house graphics, outlines, tables, object details, and other views and controls. Window management features allow you to move, resize, tab-dock, and auto-hide window panes. A window pane that is «tab-docked» is collapsed and displayed at the side of the application interface. Auto-hide indicates that a window pane (or tab-docked group of panes) automatically collapses when not in use.

Auto-Hiding Panes are either pinned or unpinned . Toggle this state by clicking the icon in the pane title bar. A pinned pane occupies space in the window. An unpinned pane collapses to a tab on the periphery of the window when inactive. To examine an unpinned pane, move the mouse pointer over the tab. This causes the pane to open overtop of any other open window panes. Holding the mouse pointer over the tab keeps the tab visible. Clicking the tab actives the window pane (also causing it to remain visible). Pin the pane to restore it to its open state.

Moving and Docking Drag a window’s title bar to move and undock a window pane. Once you begin to drag the window, a number of dock targets (blue-filled arrows and circle) appear in the interface window. At this point you:

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Main Windows 1.

Move the mouse pointer over a target to preview the resulting location for the pane. Arrow targets indicate adjacent locations; a circular target allows tab-docking of two or more panes (to share screen space).

2.

Release the button on the target to move the pane. You can abort the drag operation by pressing the ESC key.

Tip You can also double-click a window’s title bar to undock the window and move it freely around the screen. Once undocked, you can resize the window by dragging its borders/corners.

Restore Original Window Layout Choose Rest Layout from the View>Windows menu to return to the default/original pane configuration.

Main Windows In addition to the menu and toolbar structure of the interface, there are three primary graphical user interface areas of the application, and include: • Tree Outline • Details View • Geometry Window Selecting a tree object in the Outline displays attributes and controls for the selected object in the Details view. The Geometry window displays your CAD model and, based on the tree object selected, displays pertinent information about object specifications and how they relate to the displayed geometry. The Geometry window is considered a “tab”. In addition to Geometry, there is a Print Preview tab and a Report Preview tab. These tabs provide alternative views of the currently selected Outline object. These user interface elements are described in more detail in the following sections: Tree Outline Details View Geometry Window Print Preview Report Preview

Tree Outline The object Tree Outline matches the logical sequence of simulation steps. Object sub-branches relate to the main object. For example, an analysis environment object, such as Static Structural, contains loads. You can right-click on an object to open a context menu which relates to that object. You can rename objects prior to and following the solution process. Refer to the Objects Reference section of the Help for a listing and description of all of the objects available in the application. The following is an example of the Outline window pane:

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Application Interface

Note Numbers preceded by a space at the end of an object’s name are ignored. This is especially critical when you copy objects or duplicate object branches. For example, if you name two force loads as Force 1 and Force 2, then copy the loads to another analysis environment, the copied loads are automatically renamed Force and Force 2. However, if you rename the loads as Force_1 and Force_2, the copied loads retain the same names as the two original loads. The following topics present further details related to the tree outline. Understanding the Tree Outline Correlating Tree Outline Objects with Model Characteristics Suppressing Objects Filtering the Tree

Understanding the Tree Outline The Tree Outline uses the following conventions: • Icons appear to the left of objects in the tree. Their intent is to provide a quick visual reference to the identity of the object. For example, icons for part and body objects (within the Geometry object folder) can help distinguish solid, surface and line bodies. • A symbol to the left of an item’s icon indicates that it contains associated subitems. Click to expand the item and display its contents. • To collapse all expanded items at once, double-click the Project name at the top of the tree. • Drag-and-drop function to move and copy objects. • To delete a tree object from the Tree Outline (p. 3), right-click on the object and select Delete. A confirmation dialog asks if you want to delete the object.

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Main Windows • Filter tree contents and expand the tree by setting a filter and then clicking the Expand on Refresh button.

Status Symbols As described below, a small status icon displays to the left of the object icon in the Tree Outline (p. 3). Status Symbol Name

Symbol

Example A load requires a nonzero magnitude.

Underdefined

Load attachments may break during an Update.

Error

Face could not be mapped meshed, or mesh of face pair could not be matched.

Mapped Face or Match Control Failure

The object is defined properly and/or any specific action on the object is successful.

Ok

Equivalent to «Ready to Answer!»

Needs to be Updated

A body or part is hidden.

Hidden

The symbol appears for a meshed body within the Geometry folder, or for a multibody part whose child bodies are all meshed.

Meshed

An object is suppressed.

Suppress

• Yellow lightning bolt: Item has not yet been solved. • Green lightning bolt: Solve in progress. • Green check mark: Successful solution. • Red lightning bolt: Failed solution. An overlaid pause icon indicates the solution could resume with the use of restart points.

Solve

• Green down arrow: Successful background solution ready for download. • Red down arrow: Failed background solution ready for download. See also Tree Outline (p. 3).

Note The state of an environment folder can be similar to the state of a Solution folder. The solution state can indicate either solved (check mark) or not solved (lightening bolt) depending on whether or not an input file has been generated.

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Application Interface

Correlating Tree Outline Objects with Model Characteristics The Go To feature provides you with instant visual correlation of objects in the tree outline as they relate to various characteristics of the model displayed in the Geometry window. To activate this feature, right-click anywhere in the Geometry window, choose Go To, then choose an option in the context menu. In some cases (see table below), you must select geometry prior to choosing the Go To feature. The resulting objects that match the correlation are highlighted in the tree outline and the corresponding geometry is highlighted on the model. For example, you can identify contact regions in the tree that are associated with a particular body by selecting the geometry of interest and choosing the Contacts for Selected Bodies option. The contact region objects associated with the body of the selected items will be highlighted in the tree and the contact region geometry will be displayed on the model. Several options are filtered and display only if specific conditions exist within your analysis. The Go To options are presented in the following table along with descriptions and conditions under which they appear in the context menu. Go To Option

Description / Application

Required Conditions for Option to Appear

Corresponding Bodies in Tree

Identifies body objects in the tree that correspond to selections in the Geometry window.

At least one vertex, edge, face, or body is selected.

Hidden Bodies in Tree

Identifies body objects in the tree that correspond to hidden bodies in the Geometry window.

At least one body is hidden.

Suppressed Bodies in Tree

Identifies body objects in the tree that correspond to suppressed bodies in the Geometry window.

At least one body is suppressed.

Bodies Without Contacts in Tree

Identifies bodies that are not in contact with any other bodies. When you are working with complex assemblies of more than one body, it is helpful to find bodies that are not designated to be in contact with any other bodies, as they generally cause problems for a solution because they are prone to rigid body movements.

Parts Without Contacts in Identifies parts that are not Tree in contact with any other parts. When you are working with complex assemblies of more than one multibody part, it is

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More than one body in an assembly.

More than one part in an assembly.

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Main Windows Go To Option

Description / Application

Required Conditions for Option to Appear

helpful to find parts that are not designated to be in contact with any other parts. For example, this is useful when dealing with shell models which can have parts that include many bodies each. Using this feature is preferred over using the Bodies Without Contact in Tree option when working with multibody parts mainly because contact is not a typical requirement for bodies within a part. Such bodies are usually connected by shared nodes at the time of meshing. Contacts for Selected Bodies

Identifies contact region objects in the tree that are associated with selected bodies.

Contacts Common to Selected Bodies

Identifies contact region objects in the tree that are shared among selected bodies.

Joints for Selected Bodies Identifies joint objects in the tree that are associated with selected bodies. Joints Common to Selected Bodies

Identifies joint objects in the tree that are shared among selected bodies.

At least one vertex, edge, face, or body is selected.

Springs for Selected Bod- Identifies spring objects in the tree ies that are associated with selected bodies. Mesh Controls for Selected Bodies

Identifies mesh control objects in the tree that are associated with selected bodies.

Mesh Connections for Selected Bodies

Highlights mesh connection objects in the tree that are associated with the selection.

At least one vertex, edge, face, or body is selected and at least one mesh connection exists.

Mesh Connections Common to Selected Bodies

Highlights mesh connection objects in the tree that are shared among selected bodies.

At least one vertex, edge, face, or body is selected.

Field Bodies in Tree

Identifies enclosure objects in the At least one body is an enclosure. tree that are associated with selected bodies.

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Application Interface Go To Option

Description / Application

Required Conditions for Option to Appear

Bodies With One Element Through the Thickness

Identifies bodies in the tree with one element in at least two directions (through the thickness).

At least one body with one element in at least two directions (through the thickness).

This situation can produce invalid results when used with reduced integration. See At Least One Body Has Been Found to Have Only 1 Element (p. 1420) in the troubleshooting section for details. Thicknesses for Selected Faces

Identifies objects with defined thicknesses in the tree that are associated with selected faces.

At least one face with defined thickness is selected.

Body Interactions for Selected Bodies

Identifies body interaction objects At least one body interaction is in the tree that are associated with defined and at least on body is selected bodies. selected.

Body Interactions Common to Selected Bodies

Identifies body interaction objects At least one body interaction is in the tree that are shared with defined and at least on body is selected bodies. selected.

Suppressing Objects Certain objects in the Mechanical application tree outline can be suppressed, meaning that they can be individually removed from any further involvement in the analysis. For example, suppressing a part removes the part from the display and from any further loading or solution treatment. For Geometry and Environment folders, the objects that you Suppress are removed from the solved process. For Solution folder, if you suppress a solved result object, the result information will be deleted for the suppressed result object. The suppressed object is not considered in the subsequent result evaluations. You can use this feature to leave out an under-defined result object and obtain values for other results under Solution. You can Unsuppress the result object and evaluate all results to get an updated result value. To suppress results objects from the context menu, right-click the result object, and then click Suppress. Click Yes to suppress the object, or No to cancel the message box.

How to Suppress or Unsuppress Objects If available, set the Suppressed option in the Details view to Yes. Conversely, you can unsuppress items by setting the Suppressed option to No. You can also suppress/unsuppress these items through context menu options available via a right mouse button click. Included is the context menu option Invert Suppressed Body Set, which allows you to reverse the suppression state of all bodies (unsuppressed bodies become suppressed and sup-

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Main Windows pressed bodies become unsuppressed). You can suppress the bodies in a named selection using either the context menu options mentioned above, or through the Named Selection Toolbar. Another way to suppress a body is by selecting it in the graphics window, then using a right mouse button click in the graphics window and choosing Suppress Body in the context menu. Conversely, the Unsuppress All Bodies option is available for unsuppressing bodies. Options are also available in this menu for hiding or showing bodies. Hiding a body only removes the body from the display. A hidden body is still active in the analysis.

Filtering the Tree At the top of the Tree Outline window is the Tree Filter toolbar.

This toolbar enables you to filter tree items by either showing or hiding objects which match one or more search terms. Filtering options include the following: Filter Type

Description

Name

Filters the tree for or removes one or more specified search terms.

Tag

Filters for tree objects marked with one or more specified tag names. See the Tagging Objects section.

Type

Provides a drop-down list of objects for which you can filter. The options include: • All — this default option displays all tree objects and requires you to make a selection to initiate the filter process. • Results • Boundary Conditions • Connections • Commands

State

Provides a drop-down list of filters for a selected state. State options include: • All states

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Application Interface Filter Type

Description • Suppressed • Not Licensed • Underdefined

Coordinate System

Provides a drop-down list of all coordinate systems in the tree. You can select to filter for All coordinate system objects or specify an individual coordinate system object. The filter displays all objects within the tree that employ the individually selected coordinate system.

Note Note that all coordinate systems display in the filter. There are cases where an object does not have a coordinate system property in its Details view, but it does have an associated coordinate system as a requirement. As a result, it may appear as though an unaccounted for coordinate system is present. This is especially true for the Global Coordinate System.

Note Performing a search for an object that does not exist in the tree results in all objects being displayed.

Toolbar Buttons The filter toolbar buttons perform the following actions. Refresh Search Refreshes the search criteria that you have specified following changes to the environment. Clear Search Clear the filter and returns the tree to the full view. Remove Turned off by default. Depressing this button turns the feature on and off. When active, it removes the objects in question from the tree display. Expand on Refresh Turned on by default so that your modifications are automatically captured. You may «un-click» this option to turn it off.

Using the Filter Feature To filter the tree outline: 1.

Select a filter type: • Name

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Main Windows • Tag • Type • State • Coordinate System 2.

For Name and Tag, enter one or more search terms. For the other filters, select an option from the drop-down list to further specify your inquiry.

3.

Click the Refresh Search button (or press Enter) to execute your search. If you want to eliminate content from the tree, click the Remove button and then click Refresh Search to remove the requested objects.

4.

When searching, the tree displays only objects matching your search criteria. If you enter multiple search terms, the tree shows only objects matching all of the specified terms. When removing objects, the requested objects do not display.

Details View The Details view is located in the bottom left corner of the window. It provides you with information and details that pertain to the object selected in the Tree Outline (p. 3). Some selections require you to input information (e.g., force values, pressures). Some selections are drop-down dialogs, which allow you to select a choice. Fields may be grayed out. These cannot be modified. The following example illustrates the Details view for the object called Geometry.

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Application Interface

For more information, see: Features (p. 13) Header (p. 13) Categories (p. 13) Undefined or Invalid Fields (p. 14) Decisions (p. 14) Text Entry (p. 15) 12

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Main Windows Numeric Values (p. 17) Ranges (p. 17) Increments (p. 17) Geometry (p. 18) Exposing Fields as Parameters (p. 19) Options (p. 19)

Features The Details view allows you to enter information that is specific to each section of the Tree Outline. It automatically displays details for branches such as Geometry, Model, Connections, etc. Features of the Details view include: • Collapsible bold headings. • Dynamic cell background color change. • Row selection/activation. • Auto-sizing/scrolling. • Sliders for range selection. • Combo boxes for boolean or list selection. • Buttons to display dialog box (e.g. browse, color picker). • Apply / Cancel buttons for geometry selection. • Obsolete items are highlighted in red.

Header The header identifies the control and names the current object.

The header is not a windows title bar; it cannot be moved.

Categories Category fields extend across both columns of the Details Pane:

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Application Interface

This allows for maximum label width and differentiates categories from other types of fields. To expand or collapse a category, double-click the category name.

Undefined or Invalid Fields Fields whose value is undefined or invalid are highlighted in yellow:

Decisions Decision fields control subsequent fields:

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Main Windows

Note The left column always adjusts to fit the widest visible label. This provides maximum space for editable fields in the right column. You can adjust the width of the columns by dragging the separator between them.

Text Entry Text entry fields may be qualified as strings, numbers, or integers. Units are automatically removed and replaced to facilitate editing:

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Application Interface

Inappropriate characters are discarded (for example, typing a Z in an integer field). A numeric field cannot be entered if it contains an invalid value. It is returned to its previous value. Separator Clarification Some languages use “separators” within numerical values whose meanings may vary across different languages. For example, in English the comma separator [,] indicates “thousand” (“2,300” implies “two thousand three hundred”), but in German the comma separator indicates “decimal” (“2,300” implies “two and three tenths”, equivalent to “2.300” in English). To avoid misinterpretation of numerical values you enter that include separators, you are asked to confirm such entries before they are accepted. For example, in English, if you enter “2,300”, you receive a message stating the following: “Entered value is 2,300. Do you want to accept the correction proposed below? 2300 To accept the correction, click Yes. To close this message and correct the number yourself, click No.

Note If an invalid entry is detected, an attempt is made to interpret the entry as numerical and you receive the message mentioned above if an alternate value is found. If an invalid value is entered, for example «a1.3.4», and no numerical alternative is found, the entry is rejected and the previous value is re-displayed.

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Main Windows

Numeric Values You can enter numeric expressions in the form of a constant value or expression, tabular data, or a function. See Defining Boundary Condition Magnitude (p. 848) for further information.

Ranges If a numeric field has a range, a slider appears to the right of the current value:

If the value changes, the slider moves; if the slider moves the value updates.

Increments If a numeric field has an increment, a horizontal up/down control appears to the right of the current value:

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Application Interface

The arrow button controls behave the same way a slider does.

Geometry Geometry fields filter out inappropriate selection modes. For example, a bearing load can only be scoped to a face. Geometries other than face will not be accepted.

Direction fields require a special type of selection:

Clicking Apply locks the current selection into the field. Other gestures (clicking Cancel or selecting a different object or field) do not change the field’s preexisting selection.

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Main Windows

Exposing Fields as Parameters A P appears beside the name of each field that may be treated as a parameter. Clicking the box exposes the field as a parameter. For more information, see Parameterizing a Variable (p. 19).

Options Option fields allow you to select one item from a short list. Options work the same way as Decisions (p. 14), but don’t affect subsequent fields. Options are also used for boolean choices (true/false, yes/no, enabled/disabled, fixed/free, etc.) Double-clicking an option automatically selects the next item down the list. Selecting an option followed by an ellipsis causes an immediate action.

Parameterizing a Variable Variables that you can parameterize display in the interface with a check box. Clicking the check box displays a blue capital «P», as illustrated below.

The boxes that appear in the Mechanical application apply only to the Parameter Workspace. Checking or unchecking these boxes will have no effect on which CAD parameters are transferred to Design Exploration. For more information, see «Setting Parameters» (p. 1151).

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Application Interface

Geometry Window The Geometry window displays the geometry model. All view manipulation, geometry selection, and graphics display of a model occurs in this window, which contains: • 3D Graphics. • A scale ruler. • A legend and a triad control (when you display the solution). • Contour results objects.

Note When you insert a Comment, the Geometry window splits horizontally; the HTML comment editor displays in the bottom of the window, and the geometric representation of the model displays at the top. For more information about editing comments, refer to the Comment object reference.

Features of the Geometry window are described in the following sections: Viewing the Legend

Displaying Shells for Large Deflections The display of shells may become distorted for large deformations such as in large deflection, explicit dynamics analyses, etc. A workaround is to disable shell thickness by toggling View> Thick Shells and Beams on the Main Menus (p. 44). Or, set a Workbench variable, UsePseudoShellDisp = 1, via Tools> Variable Manager. It may be necessary to toggle the deformation scaling from True Scale to Undeformed to True Scale again. Note that this option requires True Scaling to work properly.

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Main Windows

Viewing the Legend To view the legend, confirm that Legend is selected in the View menu. The legend is displayed in the top left corner of the graphics window when you select an object in the tree outline. Note that the legend is not accessible via any of the toolbars in any of the modules.

Repositioning Legend To reposition the legend within the graphics window, select the legend with your mouse, hold down the left mouse button and drag the mouse. Note that the multiple view window configuration does not allow for the legend to be permanently saved in a unique location. Resumption of a database file and toggling between a single view and multiple views will result in the legend being saved to its default position in the upper left corner of the graphics window.

Discrete Legends in the Mechanical Application • Geometry Legend: Contents is driven by Display Style selection in the Details view panel. • Joint Legend: Depicts the free degrees of freedom characteristic of the type of joint. • Results Legend: Content is accessible via the right mouse when the legend for a solved object in the Solution folder is selected.

Print Preview Print Preview runs a script to generate an HTML page and image. The purpose of the Print Preview tab is to allow you to view your results or graphics image.

The title block is an editable HTML table. The table initially contains the Author, Subject, Prepared For and Date information supplied from the details view of the Project tree node. To change or add this information, double click inside the table. The information entered in the table does not propagate any changes back to the details view and is not saved after exiting the Print Preview tab. The image is generated in the same way as figures in Report.

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Application Interface

Report Preview The Report Preview tab enables you to create a report based on the analyses in the Tree Outline. This report selects items in the Tree Outline, examines the worksheets for it, then appends any material data used in the analysis. The report generation process starts immediately, and, once started, it must run to completion before you can begin working in the interface again.

You can click the Report Preview tab to create a report that covers all analyses in the Tree Outline. The process starts immediately. Unlike prior report generators, this system works by extracting information from the user interface. It first selects each item in the Outline, then examines worksheets in a second pass, and finally appends any material data used in the analysis. The material data will be expressed in the Workbench standard unit system which most closely matches the Mechanical application unit system. Once started the report generation process must run to completion. Avoid clicking anywhere else in Workbench during the run because this will stop the report process and may cause an error. This approach to reporting ensures consistency, completeness, and accuracy. This section examines the following Report Preview topics: Publishing the Report Sending the Report Comparing Databases Customizing Report Content

Tables Most tables in the report directly correspond to the Details of an object or set of related objects. Object names appear across the top of the tables. By default, tables contain no more than six columns. This limit increases the likelihood that tables will fit on the screen and on printed pages. In the Report Options dialog you can increase or decrease the limit. For example, you may allow more columns if object names take up little space, if you have a high resolution screen, or print in landscape layout. The minimum is two columns, in which case no grouping of objects occurs and the Contents is equivalent to the Outline.

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Main Windows The system merges identical table cells by default. This reduces clutter and helps to reveal patterns. You can disable this feature in the Report Options dialog.

Note The Report Preview feature does not display table entries from the nonlinear joint stiffness matrix.

Figures and Images Figures and Images appear in the report as specified in the Outline. The system automatically inserts charts as needed. The system creates all bitmap files in PNG format. You may change the size of charts and figures in the Report Options dialog. For example, you may specify smaller charts due to few data points or bigger figures if you plan to print on large paper. For best print quality, increase the Graphics Resolution in the Report Options dialog.

Publishing the Report Click the Publish toolbar button to save your report as a single HTML file that includes the picture files in a given folder, or as an HTML file with a folder containing picture files. The first option produces a single MHT file containing the HTML and pictures. MHT is the same format used by Internet Explorer when a page is saved as a “Web Archive”. Only Internet Explorer 5.5 or later on Windows supports MHT. For the other two options, the HTML file is valid XHTML 1.0 Transitional. Full support for MHT file format by any other browser cannot be guaranteed.

Sending the Report Click the Send To button to send the report as an E-mail attachment, or to open the report in Microsoft Word or import the figures into Microsoft PowerPoint. When emailing, a single MHT file is automatically attached. Note that some email systems may strip or filter MHT files from incoming messages. If this occurs, email a ZIP archive of a published report or email the report from Microsoft Word. Sending a report to Word is equivalent to opening a published HTML file in the application. Sending a report to PowerPoint creates a presentation where one figure or image appears per slide. No other data is imported.

Comparing Databases Because the report content directly corresponds to the user interface, it is easy to determine exactly how two databases differ. Generate a report for the first database, open it in Word, save and exit. Open the report for the second database in Word and choose Tools>Compare Documents. In the dialog, uncheck the Find Formatting box and select the first file. Word highlights the differences, as illustrated here:

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Application Interface

Customizing Report Content Report customization falls into two categories: preferences in the Report Options dialog and the ability to run a modified report generator from a local or network location. This ability to externalize the system is shared by the Mechanical Wizard. It allows for modifications outside of the installation folder and reuse of a customized system by multiple users. To run report externally: 1. Copy the following folder to a different location: Program Files\ANSYS Inc\v150\AISOL\DesignSpace\DSPages\Language\en-us\Report2006. 2. Specify the location under Custom Report Generator Folder in the Report Options (for example: \\server\copied_Report2006_folder). The easiest customization is to simply replace Logo.png. The system uses that image on the wait screen and on the report cover page. The file Template.xml provides the report skeleton. Editing this file allows: • Reformatting of the report by changing the CSS style rules. • Addition of standard content at specific points inside the report body. This includes anything supported by XHTML, including images and tables. The file Rules.xml contains editable configuration information: • Standard files to include and publish with reports. The first is always the logo; other files could be listed as the images used for custom XHTML content. • Rules for excluding or bolding objects in the Contents. • Rules for applying headings when objects are encountered. • Selective exclusion of an object’s details. For example, part Color (extracted as a single number) isn’t meaningful in a report. • Exclusion of Graph figures for certain objects. This overrides the other four criteria used to decide if a Graph figure is meaningful. • Rules against comparing certain types of objects. • Object states that are acceptable in a “finalized” report. 24

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Contextual Windows • Search and replace of Details text. For example, the report switches «Click to Change» to «Defined». This capability allows for the use of custom terminology. • Insertion of custom XHTML content based on object, analysis and physics types, and whether the content applies to the details table, the chart or the tabular data. For example, report includes a paragraph describing the modal analysis bar chart. All files in the Report2006 folder contain comments detailing customization techniques.

Contextual Windows A number of other windows are available. Some appear when specific tools are activated; others are available from the View>Windows menu. This section discusses the following windows: Selection Information Window Worksheet Window Graph and Tabular Data Windows Messages Window Graphics Annotation Window Section Planes Window Manage Views Window The Mechanical Wizard Window

Selection Information Window The Selection Information window provides a quick and easy way for you to interrogate and find geometric information on items that you have selected on the model. The following topics are covered in this section: Activating the Selection Information Window Understanding the Selection Modes Using the Selection Information Window Toolbar Selecting, Exporting, and Sorting Data

Activating the Selection Information Window You can display the Selection Information window using any of the following methods: • Select the Selection Information button on the Standard Toolbar (p. 49). • Choose View>Windows>Selection Information from the Main Menus (p. 44). • Double-click the field on the Status Bar that displays the geometry description.

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Application Interface

An example Selection Information window is illustrated below.

Understanding the Selection Modes The supported selection modes are vertex, edge, face, body, and coordinate. Reported information for each mode is described below.

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Contextual Windows

Vertex Individual vertex location and average location are reported. If two vertices are selected, their distance and x, y, z distances are reported. The bodies that the vertex attaches to are also reported.

Node The information displayed for selected node is similar to a vertex with addition of the Node ID.

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Application Interface

Edge Combined and individual edge length and centroid are reported. The bodies that the edge attaches to are reported. The type of the edge is also reported. If an edge is of circle type, the radius of the edge is reported.

Face Combined and individual area and centroid are reported. The bodies that the face attaches to are reported. The type of the face is reported. If a face is of cylinder type, the radius of the face is also reported.

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Contextual Windows

Body Combined and individual volume, mass, and centroid are reported. The body name is reported. Your choice of the mass moment of inertia in the selected coordinate system or the principal is also reported. The choice is provided in the Selection Information Column Control dialog box (accessible from the Using the Selection Information Window Toolbar (p. 33)).

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Application Interface

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Contextual Windows

Coordinate If there is a mesh present, the picked point location and the closest mesh node ID and location are reported.

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Application Interface

In the case of a surface body model, the closest node will be located on the non-expanded mesh (that can be seen if you turn off the option View> Thick Shells and Beams). Non-expanded shell view:

Expanded shell view:

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Contextual Windows

Using the Selection Information Window Toolbar The toolbar located at the top of the Selection Information window includes the following controls:

Each of these controls is described below.

Coordinate System A Coordinate System drop down selection box is provided on the toolbar. You can select the coordinate system under which the selection information is reported. The centroid, location, and moment of inertia information respect the selected coordinate system.

For example, if a cylindrical coordinate system is selected, the vertex location is reported using the cylindrical coordinates.

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Application Interface

Selection Information Column Control If you click the Selection Information Column Control, a column control dialog box appears to give you control over what columns are visible and what columns you can hide. The choices that you made with the column control are retained for the application.

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Contextual Windows

Note The Moment of Inertia option is unchecked by default. The following example shows the effects of un-checking the centroid for face.

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Application Interface

Selection Information Row Control The Selection Information Row Control has three options: Show Individual and Summary, Show Individual, and Show Summary. Depending upon your choice, the individual and/or summary information is reported.

Selecting, Exporting, and Sorting Data This section describes how you can reselect rows, export data, and sort data in the Selection Information window. Each function is described below.

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Contextual Windows

Reselect Right click to reselect the highlighted rows.

Export Right click to export the table to a text file or Excel file.

Sort Click on the column header to sort the table.

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Application Interface

Worksheet Window The worksheet presents you with information about objects in the tree in the form of tables, charts and text, thereby supplementing the Details view. It is typically intended to summarize data for a collection of objects (for example, the Connections folder worksheet reveals the inputs for all contacts, joints and others) or to receive tabular inputs (for example, to specify the coefficients and the analyses to include in Solution Combinations).

Behavior • Dockable Worksheet By default, when you select an applicable object in the tree, a dockable Worksheet window displays alongside the Geometry window, allowing you to review both at once. You may, however, disable the display of the Worksheet window using the Worksheet toolbar button (see below). This preference is persisted in future sessions of the product. There are specific objects that ignore the preference, as outlined below. Worksheet Function

Worksheet Behavior When Object is Selected

Example Objects

Data input and display information

Automatically appears and gains focus

Constraint Equation, Solution Combination

Display information related to object settings

Automatically appears but does not gain focus

Analysis Settings

Display information related to objects within a folder

Appears only if display is Geometry folder, Contact folder turned on manually using the Worksheet toolbar button (see below)

• Worksheet Toolbar Button

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Contextual Windows For tree objects that include an associated Worksheet, the Worksheet button on the standard toolbar allows you to toggle the Worksheet window display on or off. The button is not available (grayed out) for objects that do not include a Worksheet. Worksheets designed to display many data items do not automatically display the data. The data readily appears however when you click the Worksheet button. This feature applies to the worksheets associated with the following object folders: Geometry, Coordinate System, Contact, Remote Points, Mesh, and Solution.

Features • Go To Selected items This useful feature allows you to find items in either the tree or Geometry window that match one or more rows of the worksheet. If the worksheet displays a tabular summary of a number of objects, select the rows of interest, right-click, and choose Go To Selected Items in Tree to instantly highlight items that match the contents of the Name column (leftmost column). Control is thus transferred to the tree or Geometry window, as needed. • Viewing Selected Columns When a worksheet includes a table with multiple columns, you can control which columns to display. To do so, right-click anywhere inside the table. From the context menu, check the column names of interest to activate their display. Some columns may ignore this setting and remain hidden should they be found inapplicable. To choose the columns that will display, right mouse click anywhere inside the worksheet table. From the context menu, click on any of the column names. A check mark signifies that the column will appear. There are some columns in the worksheet that will not always be shown even if you check them. For example, if all contact regions have a Pinball Region set to Program Controlled, the Pinball Radius will not display regardless of the setting.

Graph and Tabular Data Windows Whenever you highlight the following objects in the Mechanical application tree, a Graph window and Tabular Data window appear beneath the Geometry window. • Analysis Settings • Loads • Contour Results • Probes • Charts These windows are designed to assist you in managing analysis settings and loads and in reviewing results. The Graph window provides an instant graphical display of the magnitude variations in loads and/or results, while the Tabular Data window provides instant access to the corresponding data points. Below are some of the uses of these windows.

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Application Interface

Analysis Settings For analyses with multiple steps, you can use these windows to select the step(s) whose analysis settings you want to modify. The Graph window also displays all the loads used in the analysis. These windows are also useful when using restarts. See Solution Restarts (p. 1032) for more information.

Loads Inserting a load updates the Tabular Data window with a grid to enable you to enter data on a perstep basis. As you enter the data, the values are reflected in the Graph window.

A check box is available for each component of a load in order to turn on or turn off the viewing of the load in the Graph window. Components are color-coded to match the component name in the Tabular Data window. Clicking on a time value in the Tabular Data window or selecting a row in the Graph window will update the display in the upper left corner of the Geometry window with the appropriate time value and load data. As an example, if you use a Displacement load in an analysis with multiple steps, you can alter both the degrees of freedom and the component values for each step by modifying the contents in the Tabular Data window as shown above. If you wish for a load to be active in some steps and removed in some other steps you can do so by following the steps outlined in Activation/Deactivation of Loads (p. 637).

Contour Results and Probes For contour results and probes, the Graph and Tabular Data windows display how the results vary over time. You can also choose a time range over which to animate results. Typically for results the minimum and maximum value of the result over the scoped geometry region is shown. To view the results in the Geometry window for the desired time point, select the time point in the Graph window or Tabular Data window, then click the right mouse button and choose Retrieve Results. The Details view for the chosen result object will also update to the selected step.

Charts With charts, the Graph and Tabular Data windows can be used to display loads and results against time or against another load or results item.

Context Menu Options Presented below are some of the commonly used options available in a context menu that displays when you click the right mouse button within the Graph window and/or the Tabular Data window. The options vary depending on how you are using these windows (for example, loads vs. results). • Retrieve This Result: Retrieves and presents the results for the object at the selected time point.

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Contextual Windows • Insert Step: Inserts a new step at the currently selected time in the Graph window or Tabular Data window. The newly created step will have default analysis settings. All load objects in the analysis will be updated to include the new step. • Delete Step: Deletes a step. • Copy Cell: Copies the cell data into the clipboard for a selected cell or group of cells. The data may then be pasted into another cell or group of cells. The contents of the clipboard may also be copied into Microsoft Excel. Cell operations are only valid on load data and not data in the Steps column. • Paste Cell: Pastes the contents of the clipboard into the selected cell, or group of cells. Paste operations are compatible with Microsoft Excel. • Delete Rows: Removes the selected rows. In the Analysis Settings object this will remove corresponding steps. In case of loads this modifies the load vs time data. • Select All Steps: Selects all the steps. This is useful when you want to set identical analysis settings for all the steps. • Select All Highlighted Steps: Selects a subset of all the steps. This is useful when you want to set identical analysis settings for a subset of steps. • Activate/Deactivate at this step!: This allows a load to become inactive (deleted) in one or more steps. By default any defined load is active in all steps. • Zoom to Range: Zooms in on a subset of the data in the Graph window. Click and hold the left mouse at a step location and drag to another step location. The dragged region will highlight in blue. Next, select Zoom to Range. The chart will update with the selected step data filling the entire axis range. This also controls the time range over which animation takes place. • Zoom to Fit: If you have chosen Zoom to Range and are working in a zoomed region, choosing Zoom to Fit will return the axis to full range covering all steps. Result data is charted in the Graph window and listed in the Tabular Data window. The result data includes the Maximum and Minimum values of the results object over the steps.

Exporting Data Export Tabular Data Most of the loads and results in the Mechanical application are supported through the Graph and Tabular data windows. You can export the data in the Tabular Data window in a Text and Excel File Format. To export the data in the table, right-click the table, and then select Export. The right-click menu also provides copy and paste features for this same purpose.

Export Model Information You can also export a variety of model information to a tab delimited file that Excel can read directly. The following objects allow exporting without access to worksheet data: Contour Results Node-Based Named Selections Element-Based Named Selections Imported Loads Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Application Interface The following objects require the worksheet data to be active in order to export: Connections Contact Group Contact Initial Information Contact Tool Convergence Coordinate Systems Fatigue Sensitivities Frequency Response Geometry Mesh Solution Thermal Condition

Note When you select Top/Bottom as the Shell setting in the Details view for a surface body and export the result contours (such as stresses and strains), the export file contains two results for every node on a shell element. The first result is for the bottom face and the second result is for the top face. Steps to export 1.

Select an object in the tree.

2.

Click the Worksheet to give it focus (if applicable).

3.

Right-mouse click the selected object in the tree to produce the menu, then select Export.

4.

Specify a file name for the Excel file and save the file. Once saved, Excel opens automatically if installed on your computer.

Note You must right-mouse click on the selected object in the tree to use this Export feature. On Windows platforms, if you have the Microsoft Office 2002 (or later) installed, you may see an Export to Excel option if you right-mouse click in the Worksheet. This is not the Mechanical application Export feature but rather an option generated by Microsoft Internet Explorer.

Options Settings The Export the Mechanical application settings in the Options dialog box allows you to: Automatically Open Excel (Yes by default) Include Node Numbers (Yes by default) Include Node Location (No by default)

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Contextual Windows

Messages Window The Messages Window is a Mechanical application feature that prompts you with feedback concerning the outcome of actions you have taken in the Mechanical application. For example, Messages display when you resume a database, Mesh a model, or when you initiate a Solve. Messages come in three forms: • Error • Warning • Information By default the Messages Window is hidden, but displays automatically as a result of irregularities during Mechanical application operations. To display the window manually: select View>Windows>Messages. An example of the Messages Window is shown below.

In addition, the status bar provides a dedicated area (shown above) to alert you should one or more messages become available to view. The Messages Window can be auto-hidden or closed using the buttons on the top right corner of the window.

Note You can toggle between the Graph and Messages windows by clicking a tab. Once messages are displayed, you can: • Double-click a message to display its contents in a pop-up dialog box. • Highlight a message and then press the key combination Ctrl + C to copy its contents to the clipboard. • Press the Delete key to remove a selected message from the window. • Select one or more messages and then use the right mouse button click to display the following context menu options: – Go To Object — Selects the object in the tree which is responsible for the message. – Show Message — Displays the selected message in a popup dialog box. – Copy — Copies the selected messages to the clipboard. – Delete — Removes the selected messages.

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Application Interface – Refresh — Refreshes the contents of the Messages Window as you edit objects in the Mechanical application tree.

Graphics Annotation Window This window is displayed when you choose the User Defined Graphics Annotation button located on the Standard Toolbar. See the description of that button in the Standard Toolbar (p. 49) section for more information.

Section Planes Window The Section Plane window gives you access to the functionality for creating a cut or slice on your model so that you can view internal geometry, or mesh and results displays. For more information on this feature, see Creating Section Planes (p. 109).

Manage Views Window The Manage Views window gives you access to the functionality for saving graphical views and returning to a specific view at any time. For more information, see Managing Graphical View Settings (p. 107).

The Mechanical Wizard Window The Mechanical Wizard window appears in the right side panel whenever you click the Standard Toolbar (p. 49). See the The Mechanical Wizard (p. 123) section for details.

in the

Main Menus The main menus include the following items.

File Menu Edit Menu View Menu Units Menu Tools Menu Help Menu

File Menu Function

Description

Refresh All Data

Updates the geometry, materials, and any imported loads that are in the tree.

Save Project

Allows you to save the project.

Export

Allows you to export outside of the project. You can export a .mechdat file (when running the Mechanical application) that later can be imported into a new Workbench project. Note that only the data native to the Mechanical application is saved to the .mechdat file. External files (such as solver files) will not be exported. You can also export the mesh for input to any of the following: Fluent (.msh), Polyflow (.poly), CGNS (.cgns), and ICEM CFD (.prj).

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Main Menus Function

Description

Clear Generated Data

Clears all results and meshing data from the database depending on the object selected in the tree.

Close Mechanical

Exits the Mechanical application session.

Edit Menu Function

Description

Duplicate

Duplicates the object you highlight. The model and environment duplication is performed at the Project Schematic level (see Moving, Deleting, and Replacing Systems for details).

Duplicate Without Results

(Only available on solved result objects.) Duplicates the object you highlight, including all subordinate objects. Because the duplicated objects have no result data the process is faster than performing Duplicate.

Copy

Copies an object.

Cut

Cuts the object and saves it for pasting.

Paste

Pastes a cut or copied object.

Delete

Deletes the object you select.

Select All

Selects all items in the Model of the current selection filter type. Select All is also available in a context menu if you click the right mouse button in the Geometry window.

View Menu Function

Description

Shaded Exterior and Edges

Displays the model in the graphics window with shaded exteriors and distinct edges. This option is mutually exclusive with Shaded Exterior and Wireframe.

Shaded Exterior

Displays the model in the graphics window with shaded exteriors only. This option is mutually exclusive with Shaded Exterior and Edges and Wireframe. Displays the model in the Geometry window with a wireframe display rather than a shaded one (recommended for seeing gaps in surface bodies). This option is mutually exclusive with Shaded Exterior and Edges and Shaded Exterior. The Wireframe option not only applies to geometry, mesh, or named selections displayed as a mesh, but extends to probes, results, and variable loads to enable a better understanding of regions of interest.

Wireframe

When the View> Wireframe option is set, just the exterior faces of the meshed models are shown, not the interior elements. Note that when this option is on, green scoping is not drawn on probes. Also, elements are shown on probes and results, whereas the outline of the mesh is shown on isoline contour results. Selecting any of the edges options on contour results automatically closes Wireframe mode.

Graphics Options

Allows you to change the drawing options for edge connectivity. Most of these options are also available on the Edge Graphics Options toolbar. See the Edge Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Application Interface Function

Description Graphics Options (p. 71) section for additional details. This menu also provides the Draw Face Mode menu that allows you to change how faces are displayed as a function of back-face culling. Options include: • Auto Face Draw (default) — turning back-face culling on or off is program controlled. Using Section Planes is an example of when the application would turn this feature off. • Draw Front Faces — face culling is forced to stay on. Back-facing faces will not be drawn in any case, even if using Section Planes. • Draw Both Faces — back-face culling is turned off. Both front-facing and back-facing faces are drawn. See the Displaying Interior Mesh Faces section in the of the Help for a related discussion of how these options are used.

Cross Section Solids (Geometry)

Displays line body cross sections in 3D geometry. See Viewing Line Body Cross Sections (p. 388) for details.

Thick Shells and Beams

Toggles the visibility of the thickness applied to a shell or beam in the graphics window when the mesh is selected. See notes below.

Visual Expansion

Toggles the visibility of either a single cyclic sector mesh or the full symmetry mesh in a cyclic symmetry analysis. Toggling this option can help preview before solving the density of nodes on the sector boundaries, or it can help confirm the expanded mesh in each case.

Annotation PreferDisplays the Annotation Preferences dialog box. ences Annotations

Toggles the visibility of annotations in the graphics window.

Ruler

Toggles the visibility of the visual scale ruler in the graphics window.

Legend

Toggles the visibility of the results legend in the graphics window.

Triad

Toggles the visibility of the axis triad in the graphics window.

Eroded Nodes

Toggles the visibility of eroded nodes for explicit dynamics analyses.

Large Vertex Contours

Used in mesh node result scoping to toggle the size of the displayed dots that represent the results at the underlying mesh nodes.

Display Edge Direction

Displays model edge directions. The direction arrow appears at the midpoint of the edge. The size of the arrow is proportional to the edge length. Expand All — Restores tree objects to their original expanded state.

Outline

Collapse Environments — Collapses all tree objects under the Environment object(s). Collapse Models — Collapses all tree objects under the Model object(s). Named Selections — Displays the Named Selection Toolbar (p. 69). Unit Conversion — Displays the Unit Conversion Toolbar (p. 69).

Toolbars

Graphics Options — Displays the Graphics Options Toolbar (p. 69). Edge Graphics Options — Displays the Edge Graphics Options (p. 71). Tree Filter — Displays the Tree Filter Toolbar (p. 73). Joint Configure — Displays the Joint Configure Context Toolbar (p. 57).

Windows

Messages — Toggles the display of the Messages window.

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Main Menus Function

Description Mechanical Wizard — Toggles the display of a wizard on the right side of the window which prompts you to complete tasks required for an analysis. Graphics Annotations — Toggles the display of the Annotations window. Section Planes — Toggles the display of the Section Planes window. Selection Information — Toggles the display of the Selection Information window. Manage Views — Toggles the display of the Manage Views window. Tags — Toggles the display of the Tags window. Reset Layout — Restores the Window layout back to a default state.

Notes: • Displaying Shells for Large Deflections: The display of shells may become distorted for large deformations such as in large deflection or during an Explicit Dynamics analyses. A workaround for this is to disable Shell Thickness by toggling View>Thick Shells and Beams. Or, set a Workbench variable, UsePseudoShellDisp = 1, through Tools> Variable Manager. It may be necessary to toggle the deformation scaling from True Scale to Undeformed to True Scale again (see Scaling Deformed Shape in the Context Toolbar Section). Note that this option requires True Scaling to work properly. • Displaying Shells on Shared Entities: The display of shells is done on a nodal basis. Therefore, graphics plot only 1 thickness per node, although node thickness can be prescribed and solved on a per elemental basis. When viewing shell thickness at sharp face intersections or a shared body boundary, the graphics display may become distorted. • Displaying Contours and Displaced Shapes on Line Bodies: The contour result on a line body are expanded to be viewed on the cross section shape, but only one actual result exists at any given node and as a result no contour variations across a beam section occur. • Display Pipes using Pipe Idealizations: Although the solution will account for cross section distortions, the graphics rendering for the results display the cross sections in their original shape.

Units Menu Function

Description

Metric (m, kg, N, s, V, A)

Sets unit system.

Metric (cm, g, dyne, s, V, A) Metric (mm, kg, N, s, mV, mA) Metric (mm, t, N, s, mV, mA) Metric (mm, dat, N, s, mV, mA) Metric (µm, kg, µN, s, V, mA) U.S. Customary (ft, lbm, lbf, °F, s, V, A) U.S. Customary (in, lbm, lbf, °F, s, V, A) Degrees

Sets angle units to degrees.

Radians

Set angle units to radians.

rad/s

Sets angular velocity units to radians per second.

RPM

Sets angular velocity units to revolutions per minute.

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Application Interface Function

Description

Celsius

Sets the temperature values to degree Celsius (not available if you choose either of the U.S. Customary settings).

Kelvin

Sets the temperature values to Kelvin (not available if you choose either of the U.S. Customary settings).

Tools Menu Function

Description

Write Input File…

Writes the Mechanical APDL application input file from the active Solution branch. This option does not initiate a Solve.

Read Result File…

Reads the Mechanical APDL application result files (.rst, solve.out, and so on) in a directory and copies the files into the active Solution branch.

Solve Process Settings

Allows you to configure solve process settings.

Addins…

Launches the Addins manager dialog that allows you to load/unload third-party add-ins that are specifically designed for integration within the Workbench environment.

Options…

Allows you to customize the application and to control the behavior of Mechanical application functions.

Variable Manager

Allows you to enter an application variable.

Run Macro…

Opens a dialog box to locate a script (.vbs , .js ) file.

Help Menu Function

Description

Mechanical Help

Displays the Help system in another browser window.

About Mechanical

Provides copyright and application version information.

Note View menu settings are maintained between Mechanical application sessions except for the Outline items and Reset Layout in the Windows submenu.

Toolbars Toolbars are displayed across the top of the window, below the menu bar. Toolbars can be docked to your preference. The layouts displayed are typical. You can double-click the vertical bar in the toolbar to automatically move the toolbar to the left. The various toolbars are described in the following sections: Standard Toolbar Graphics Toolbar Context Toolbar Named Selection Toolbar Unit Conversion Toolbar Graphics Options Toolbar

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Toolbars Edge Graphics Options Tree Filter Toolbar

Standard Toolbar

The Standard Toolbar contains application-level commands, configuration toggles and important general functions. Each icon button and its description follows: Icon Button

Application-level command

Description

View Mechanical Wizard

Activates the Mechanical Wizard in the user interface.

View Object Generator

Activates the Object Generator window in the user interface.

Solve analysis with a given solve process setting.

Drop-down list to select a solve process setting.

Show Errors

Displays error messages associated with tree objects that are not properly defined.

New Section Plane

View a section cut through the model (geometry, mesh and results displays) as well as obtained capped displays on either side of the section. Refer to the Creating Section Planes (p. 109) section for details.

User Defined Graphics Annotation

Adds a text comment for a particular item in the Geometry window. To use: • Select button in toolbar. • Click a placement location on the geometry. A chisel-shaped annotation is anchored in 3D. • A blank annotation appears and the Graphics Annotation window is made visible or brought forward. • A new row is created for the annotation. • Type entry. To edit, double click the corresponding entry in the Graphics Annotation window and type new information. To delete, select the entry and press the delete key. To move, select the annotation in the geometry window and move while pressing down the left mouse button. To exit without creating an annotation, re-click the annotation button.

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Application Interface Icon Button

Application-level command

Description

New Chart and Table

Refer to the Chart and Table (p. 988) section for details.

New Simplorer Pin

For Rigid Dynamic analyses, Simplorer Pins are used to define/describe interface points between a Simplorer model and the joints of the Rigid Dynamics model.

New Comment

Adds a comment within the currently highlighted outline branch.

New Figure

Captures any graphic displayed for a particular object in the Geometry window.

New Image

Adds an image within the currently highlighted outline branch.

Image from File

Imports an existing graphics image.

Image to File

Saves the current graphics image to a file (.png, .jpg, .tif, .bmp, .eps).

Note The Aero Theme display mode in Windows 7 is incompatible with the screen capture used in Mechanical. If you are running Windows 7, select a Basic Theme display mode to restore this capability. Show/Hide Worksheet Window

Enables Worksheet window to be displayed for specific objects.

Selection Information

Activates the Selection Information Window (p. 25).

Graphics Toolbar The Graphics Toolbar sets the selection/manipulation mode for the cursor in the graphics window. The toolbar also provides commands for modifying a selection or for modifying the viewpoint. Each icon button and its description follows: Icon Button

Tool Tip Name Displayed Label

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Description Allows you to move and place the label of a load anywhere along the feature that the load is currently scoped to.

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Toolbars Icon Button

Tool Tip Name Displayed

Description

Direction

Chooses a direction by selecting either a single face, two vertices, or a single edge (enabled only when Direction field in the Details view has focus). See Pointer Modes.

Hit Point Coordinate

(Active only if you are setting a location, for example, a local coordinate system.) Enables the exterior coordinates of the model to display adjacent to the cursor and updates the coordinate display as the cursor is moved across the model. If you click with the cursor on the model, a label displays the coordinates of that location. This feature is functional on faces only. It is not functional on edges or line bodies.

Select Type

• Select Geometry: This option allows you to select geometric entities (bodies, faces, edges, and vertices). • Select Mesh: This option allows you to select nodes or a group of nodes by picking the node or nodes graphically or by defining a node or group of nodes as a Named Selection. Note that you must first generate the mesh.

Select Mode

Defines how geometry or node selections are made: • Single Select • Box Select • Box Volume Select • Lasso Select • Lasso Volume Select These options are used in conjunction with the selection filters (Vertex, Edge, Face, Body)

Note Selection shortcuts: • You can change your selection mode from Single Select to Box Select by holding the right mouse button and then clicking the left mouse button. • Given a generated mesh and that the Mesh Select option is active, holding the right mouse button and then clicking the left mouse button scrolls through the available selection options (single section, box selection, box volume, lasso, lasso volume).

Vertex

Designates vertex or node only for picking or viewing selection.

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Application Interface Icon Button

Tool Tip Name Displayed

Description

Edge

Designates edges only for picking or viewing selection.

Face

Designates faces only for picking or viewing selection.

Body

Designates bodies only for picking or viewing selection.

Extend Selection

Adds adjacent faces (or edges) within angle tolerance, to the currently selected face (or edge) set, or adds tangent faces (or edges) within angle tolerance, to the currently selected face (or edge) set.

Rotate

Activates rotational controls based on the positioning of the mouse cursor.

Pan

Moves display model in the direction of the mouse cursor.

Zoom

Displays a closer view of the body by dragging the mouse cursor vertically toward the top of the graphics window, or displays a more distant view of the body by dragging the mouse cursor vertically toward the bottom of the graphics window.

Box Zoom

Displays selected area of a model in a box that you define.

Fit

Fits the entire model in the graphics window.

Toggle Magnifier Window On/Off

Displays a Magnifier Window, which is a shaded box that functions as a magnifying glass, enabling you to zoom in on portions of the model. When you toggle the Magnifier Window on, you can: • Pan the Magnifier Window across the model by holding down the left mouse button and dragging the mouse. • Increase the zoom of the Magnifier Window by adjusting the mouse wheel, or by holding down the middle mouse button and dragging the mouse upward. • Recenter or resize the Magnifier Window using a right mouse button click and choosing an option from the context menu. Recenter the window by choosing Reset Magnifier. Resizing options include Small Magnifier, Medium Magnifier, and Large Magnifier for preset sizes, and Dynamic Magnifier Size On/Off for gradual size control accomplished by adjusting the mouse wheel. Standard model zooming, rotating, and picking are disabled when you use the Magnifier Window.

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Previous View

To return to the last view displayed in the graphics window, click the Previous View button on the toolbar. By continuously clicking you can see the previous views in consecutive order.

Next View

After displaying previous views in the graphics window, click the Next View button on the toolbar to scroll forward to the original view.

Set (ISO)

The Set ISO button allows you to set the isometric view. You can define a custom isometric viewpoint based on the current viewpoint Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

Toolbars Icon Button

Tool Tip Name Displayed

Description (arbitrary rotation), or define the «up» direction so that geometry appears upright.

Look at

Centers the display on the currently selected face or plane.

Manage Views

Displays the Manage Views window, which you can use to save graphical views.

Rescale Annotation

Adjusts the size of annotation symbols, such as load direction arrows.

Tags

Displays the Tags window, where you can mark objects in the tree with meaningful labels, which can then be used to filter the tree.

Viewports

Splits the graphics display into a maximum of four simultaneous views.

Keyboard Support The same functionality is available via your keyboard provided the NumLock key is enabled. The numbers correlate to the following functionality: 0 = View Isometric 1 = +Z Front 2 = -Y Bottom 3 =+X Right 4 = Previous View 5 = Default Isometric 6 = Next View 7 = -X Left 8 = +Y Top 9 = -Z Back . (dot) = Set Isometric

Context Toolbar The Context Toolbar configures its buttons based on the type of object selected in the Tree Outline (p. 3). The Context Toolbar makes a limited number of relevant choices more visible and readily accessible. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Application Interface Context Toolbars include: • Model Context Toolbar (p. 55) • Geometry Context Toolbar (p. 56) • Virtual Topology Context Toolbar (p. 56) • Symmetry Context Toolbar (p. 56) • Connections Context Toolbar (p. 57) • Joint Configure Context Toolbar (p. 57) • Coordinate System Context Toolbar (p. 57) • Meshing Context Toolbar (p. 58) • Fracture Context Toolbar (p. 58) • Gap Tool Context Toolbar (p. 58) • Environment Context Toolbar (p. 58) • Variable Data Toolbar (p. 59) • Solution Context Toolbar (p. 59) • Solution Information Toolbar (p. 59) • Vector Display Context Toolbar (p. 64) • Result Context Toolbar (p. 59) • Geometry (p. 62) • Comment Context Toolbar (p. 68) • Print Preview Context Toolbar (p. 69) • Report Preview Context Toolbar (p. 69)

Note • Some Context Toolbar items, such as Connections or Mesh Controls, can be hidden. • Some Context Toolbar items cannot be hidden (for simplicity and to avoid jumbling the screen). The toolbar appears blank when no options are relevant. • The toolbar displays a text label for the current set of options. • A Workbench Options dialog box setting turns off button text labels to minimize context toolbar width.

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Toolbars

Model Context Toolbar

The Model Context toolbar becomes active when the Model object is selected in the tree. The Model Context toolbar contains options for creating objects related to the model, as described below. Construction Geometry See the Path (Construction Geometry) (p. 453) and Surface (Construction Geometry) (p. 459) sections for details. Virtual Topology You can use the Virtual Topology option to reduce the number of elements in a model by merging faces and lines. This is particularly helpful when small faces and lines are involved. The merging will impact meshing and selection for loads and supports. See Virtual Topology Overview for details. Symmetry For symmetric bodies, you can remove the redundant portions based on the inherent symmetry, and replace them with symmetry planes. Boundary conditions are automatically included based on the type of analyses. Remote Point See the Remote Point (p. 460) section for details. Connections The Connections button is available only if a connection object is not already in the tree (such as a model that is not an assembly), and you wish to create a connections object. Connection objects include contact regions, joints, and springs. You can transfer structural loads and heat flows across the contact boundaries and “connect” the various parts. See the Contact section for details. A joint typically serves as a junction where bodies are joined together. Joint types are characterized by their rotational and translational degrees of freedom as being fixed or free. See the Joints section for details. You can define a spring (longitudinal or torsional) to connect two bodies together or to connect a body to ground. See the Springs section for details. Mesh Numbering The Mesh Numbering feature allows you to renumber the node and element numbers of a generated meshed model consisting of flexible parts. See the Mesh Numbering (p. 451) section for details. Solution Combination Use the Solution Combination option to combine multiple environments and solutions to form a new solution. A solution combination folder can be used to linearly combine the results from an arbitrary number of load cases (environments). Note that the analysis environments must be static structural with no solution convergence. Results such as stress, elastic strain, displacement, contact, and fatigue may be requested. To add a load case to the solution combination folder, right click on the worksheet view of the solution combination folder, choose add, and then select the scale factor and the environment name. An environment may be added more than once and its effects will be cumulative. You may suppress the effect of a load case by using the check box in the worksheet view or by deleting it through a right click. For more information, see Solution Combinations (p. 1019).

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Application Interface Named Selection You can create named selections to specify and control like-grouped items such as types of geometry. For more information, see Named Selections (p. 429).

Geometry Context Toolbar

The Geometry Context toolbar is active when you select the Geometry branch in the tree or any items within the Geometry branch. If you are using an assembly meshing algorithm, you can use the Geometry toolbar to insert a virtual body. Using the Geometry toolbar you can also apply a Point Mass or a Thermal Point Mass. You can also add a Commands object to individual bodies. For surface bodies, you can add a Thickness object or an Imported Thickness object to define variable thickness, or Layered Section objects to define layers applied to surfaces.

Construction Geometry

See Path (Construction Geometry) (p. 453) and Surface (Construction Geometry) (p. 459) for details.

Virtual Topology Context Toolbar The Virtual Topology Context toolbar includes the following controls: • Merge Cells button: For creating Virtual Cell objects in which you can group faces or edges. • Split Edge at + and Split Edge buttons: For creating Virtual Split Edge objects, which allow you to split an edge to create two virtual edges. • Split Face at Vertices button: For creating Virtual Split Face objects, which allow you to split a face along two vertices to create 1 to N virtual faces. The selected vertices must be located on the face that you want to split. • Hard Vertex at + button: For creating Virtual Hard Vertex objects, which allow you to define a hard point according to your cursor location on a face, and then use that hard point in a split face operation. •

and buttons: For cycling through virtual topology entities in the sequence in which they were created. If any virtual topologies are deleted or merged, the sequence is adjusted automatically. See Cycling Through Virtual Entities in the Geometry Window.

• Edit button: For editing virtual topology entities. • Delete button: For deleting selected virtual topology entities, along with any dependents if applicable.

Symmetry Context Toolbar The Symmetry Context toolbar includes an option to insert Symmetry Region, Periodic Region, or Cyclic Region objects where you can define symmetry planes.

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Toolbars

Connections Context Toolbar The Connections context toolbar includes the following settings and functions: • Connection Group button: Inserts a Connection Group object. • Contact drop down menu: Inserts one of the following: a manual Contact Region object set to a specific contact type, a Contact Tool object (for evaluating initial contact conditions), or a Solution Information object. • Spot Weld button: Inserts a Spot Weld object. • Mesh Connection button: Inserts a Mesh Connection object. • End Release button: Inserts an End Release object. • Body Interactions See Body Interactions in Explicit Dynamics Analyses (p. 619) for details. • Body-Ground drop-down menu: Inserts a type of Joint object, Spring object, or a Beam object, whose reference side is fixed. • Body-Body drop-down menu: Inserts a type of Joint object, Spring object, or a Beam object, where neither side is fixed. • Body Views toggle button: For joints, Mesh Connections, and Contacts, displays parts and connections in separate auxiliary windows. • Sync Views toggle button: When the Body Views button is engaged, any manipulation of the model in the Geometry window will also be reflected in both auxiliary windows. • Commands icon button: Inserts a Commands object.

Joint Configure Context Toolbar

The Joint Configure context toolbar includes the following settings and functions: • Configure, Set, and Revert buttons; and ∆ = field: Graphically configures the initial positioning of a joint. Refer to Example: Configuring Joints (p. 576) for details. • Assemble button: For joints, performs the assembly of the model, finding the closest part configuration that satisfies all the joints. This toolbar only displays when you have a Joint selected. It can be displayed manually by selecting View>Toolbars>Joint Configure.

Coordinate System Context Toolbar

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Application Interface The Coordinate System context toolbar includes the following options: • Create Coordinate System: use the Create Coordinate System button ( a coordinate system.

) on the toolbar to create

• Transform the coordinate system using one of the following features: – Translation: Offset X, Offset Y, or Offset Z. – Rotation: Rotate X, Rotate Y, or Rotate Z. – Flip: Flip X, Flip Y, or Flip Z. – Move Up and Move Down: scroll up or down through the Transformation category properties. – Delete: delete Transformation category properties.

Meshing Context Toolbar

The Meshing Context toolbar includes the following controls: • Update button — for updating a cell that references the current mesh. This will include mesh generation as well as generating any required outputs. • Mesh drop down menu — for implementing meshing ease of use features. • Mesh Control drop down menu — for adding Mesh Controls to your model. • Metric Graph button — for hiding and showing the Mesh Metrics bar graph.

Fracture Context Toolbar

The Fracture Context toolbar allows you to apply the objects associated with a Fracture Analysis, including Cracks as well as progressive failure features in the form of Interface Delamination and Contact Debonding objects.

Gap Tool Context Toolbar

The Gap Tool Context toolbar is used to have the Mechanical application search for face pairs within a specified gap distance that you specify.

Environment Context Toolbar

The Environment Context toolbar allows you to apply loads to your model. The toolbar display varies depending on the type of simulation you choose. For example, the toolbar for a Static Structural analysis is shown above.

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Toolbars

Variable Data Toolbar

The Variable Data toolbar allows you to view contours or the isoline representation of variable data, including spatial varying loads, imported loads, and thicknesses. You can also view the variable data as an isoline.

Note • The isoline option is drawn based on nodal values. When drawing isolines for imported loads that store element values (Imported Body Force Density, Imported Convection, Imported Heat Generation, Imported Heat Flux, Imported Pressure, and Imported Surface Force Density), the program automatically calculates nodal values by averaging values of the elements to which a node is attached. • This toolbar is not available for Imported Loads that are scoped to nodal-based Named Selections.

Solution Context Toolbar

The Solution toolbar applies to Solution level objects that either: • Never display contoured results (such as the Solution object), or • Have not yet been solved (no contours to display). The options displayed on this toolbar are based on the type of analysis that is selected. The example shown above displays the solution options for a static structural analysis. Objects created via the Solution toolbar are automatically selected in the Outline. Prior to a solution this toolbar always remains in place (no contours to display). A table in the Applying Results Based on Geometry (p. 858) section indicates which bodies can be represented by the various choices available in the drop-down menus of the Solution toolbar.

Solution Information Toolbar

Selecting the Solution Information object displays a corresponding toolbar. It’s options include the Result Tracker drop-down menu and the Retrieve button. The Retrieve feature allows you to track background solutions.

Result Context Toolbar

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Application Interface The Result toolbar applies to Solution level objects that display contour or vector results. The following subsections describe the options available on this toolbar. • Scaling Deformed Shape (p. 60) • Relative Scaling (p. 61) • Geometry (p. 62) • Contours Options (p. 62) • Edges Options (p. 63) • Vector Display Context Toolbar (p. 64) • Max, Min, and Probe Annotations (p. 66) • Display (p. 66)

Scaling Deformed Shape For results with an associated deformed shape, the Scaling combo box provides control over the onscreen scaling:

Scale factors precede the descriptions in parentheses in the list. The scale factors shown above apply to a particular model’s deformation and are intended only as an example. Scale factors vary depending on the amount of deformation in the model. You can choose a preset option from the list or you can type a customized scale factor relative to the scale factors in the list. For example, based on the preset list shown above, typing a customized scale factor of 0.6 would equate to approximately 3 times the Auto Scale factor. • Undeformed does not change the shape of the part or assembly. • True Scale is the actual scale. • Auto Scale scales the deformation so that it’s visible but not distorting. • The remaining options provide a wide range of scaling. The system maintains the selected option as a global setting like other options in the Result toolbar. As with other presentation settings, figures override the selection.

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Toolbars For results that are not scaled, the combo box has no effect.

Note Most of the time, a scale factor will be program chosen to create a deformed shape that will show a visible deflection to allow you to better observe the nature of the results. However, under certain conditions, the True Scale displaced shape (scale factor = 1) is more appropriate and is therefore the default if any of the following conditions are true: • Rigid bodies exist. • A user-defined spring exists in the model. • Large deflection is on. This applies to all analyses except for modal and linear buckling analyses (in which case True Scale has no meaning). Currently, if you are performing a Modal or Linear Buckling analysis that includes rigid body parts, the application is experiencing a limitation while scaling and/or animating results. The motion of rigid parts is subject to changes in the position of the center of mass (linear displacement) and changes in rotation (angular displacements). Because linear displacement and angular displacement are different concepts, a scaling (other than True) that satisfies both (and one which is calculated quickly) has not yet been implemented. Therefore, True scale is the best setting when animating rigid parts. For the best scaling results when working on a Modal analysis (where displacements are not true), use the Auto Scale option. However, when you have multiple scaling options selected, such as a body whose optimal scaling is True and another body whose optimal scaling is Auto Scale, then the graphical display of the motion of the bodies does not appear cleanly. For random vibration (PSD) and response spectrum analyses, Mechanical sets the scale factor to zero. In this case, the image of the finite element model does not deform.

Relative Scaling The combo list provides five «relative» scaling options. These options scale deformation automatically relative to preset criteria: • Undeformed • True Scale • 0.5x Auto • Auto Scale • 2x Auto • 5x Auto

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Application Interface

Geometry You can observe different views from the Geometry drop-down menu.

• Exterior This view displays the exterior results of the selected geometry. • IsoSurfaces This view displays the interior only of the model at the transition point between values in the legend, as indicated by the color bands. • Capped IsoSurfaces This view displays contours on the interior and exterior. When you choose Capped IsoSurfaces, a Capped Isosurface toolbar appears beneath the Result context toolbar. Refer to Capped Isosurfaces for a description of the controls included in the toolbar. • Section Planes This view displays planes cutting through the result geometry; only previously drawn Section Planes are visible. The model image changes to a wireframe representation.

Contours Options To change the way you view your results, click any of the options on this toolbar.

• Smooth This view displays gradual distinction of colors. • Contour This view displays the distinct differentiation of colors. • Isolines This view displays a line at the transition between values. 62

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Toolbars • Solid This view displays the model only with no contour markings.

Edges Options You can switch to wireframe mode to see gaps in surface body models. Red lines indicate shared edges. In addition, you can choose to view wireframe edges, include the deformed model against the undeformed model, or view elements. Showing a subdued view of the undeformed model along with the deformed view is especially useful if you want to view results on the interior of a body yet still want to view the rest of the body’s shape as a reference. An example is shown here.

The Show Undeformed Model option is useful when viewing any of the options in the Geometry dropdown menu.

• No Wireframe This view displays a basic picture of the body. • Show Undeformed Wireframe This view shows the body outline before deformation occurred. If the Creating Section Planes (p. 109) feature is active, choosing Show Undeformed WireFrame actually displays the wireframe with the deformations added to the nodes. This is intended to help you interpret the image when you drag the section plane anchor across smaller portions of the model. • Show Undeformed Model This view shows the deformed body with contours, with the undeformed body in translucent form. • Show Elements This view displays element outlines.

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Application Interface

Vector Display Context Toolbar Using the Graphics button, you can display results as vectors with various options for controlling the display.

• Click the Graphics button on the Result context toolbar to convert the result display from contours (default) to vectors. • When in vector display, a Vector Display toolbar appears with controls as described below.

Displays vector length proportional to the magnitude of the result. Displays a uniform vector length, useful for identifying vector paths. Controls the relative length of the vectors in incremental steps from 1 to 10 (default = 5), as displayed in the tool tip when you drag the mouse cursor on the slider handle. Displays all vectors, aligned with each element. Displays vectors, aligned on an approximate grid. Controls the relative size of the grid, which determines the quantity (density) of the vectors. The control is in uniform steps from 0 [coarse] to 100 [fine] (default = 20), as displayed in the tool tip when you drag the mouse cursor on the slider handle.

Note This slider control is active only when the adjacent button is chosen for displaying vectors that are aligned with a grid. Displays vector arrows in line form. Displays vector arrows in solid form.

• When in vector display, click the Graphics button on the Result context toolbar to change the result display back to contours. The Vector Display toolbar is removed. Presented below are examples of vector result displays.

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Toolbars

Uniform vector lengths identify paths using vector arrows in line form.

Course grid size with vector arrows in solid form.

Same using wireframe edge option.

Uniform vector lengths , grid display on section plane with vector arrows in solid form.

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Application Interface

Zoomed-in uniform vector lengths , grid display with arrow scaling and vector arrows in solid form.

Max, Min, and Probe Annotations

Toolbar buttons allow for toggling Max and Min annotations and for creating probe annotations. See also Viewing Annotations (p. 114).

Display

The Display feature on the Result Context Toolbar allows you to view: • All Bodies — Regions of the model not being drawn as a contour are plotted as translucent even for unscoped bodies as long as the bodies are visible (not hidden).

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Toolbars

• Scoped Bodies — (default setting) Regions of the model not being drawn as a contour are plotted as translucent for scoped bodies only. Unscoped bodies are not drawn.

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Application Interface • Results Only — Only the resultant contour or vector is displayed.

Limitations The following limitations apply to this feature: • The Scoped Bodies and Results Only options support geometry-based scoping (Geometry Selection property = Geometry) and Named Selections that are based on geometry selections or worksheet criteria. • The Scoped Bodies and Results Only options do not support Construction Geometry features Path and Surface. • The Results Only option does not support the Explicit Dynamics Solver (AUTODYN). • For the Scoped Bodies option for results that are scoped across multiple entities (vertices, edges, faces, or volumes), all of these entities may not display because there are times when only the nodes of one of the shared entities are used in the calculation.

Comment Context Toolbar

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Toolbars When you select the Comment button in the standard toolbar or when you select a Comment object already in the tree, the Comment Context toolbar and Comment Editor appear. The buttons at the top allow you to insert an image or apply various text formatting. To insert an image, click the button whose tool tip is Insert Image, then complete the information that appears in the dialog box. For the Image URL, you can use a local machine reference (C:\…) or a web reference (http:\\…).

Print Preview Context Toolbar

The Print Preview toolbar allows you to print the currently-displayed image, or send it to an e-mail recipient or to a Microsoft Word or PowerPoint file.

Report Preview Context Toolbar The Report Preview toolbar allows you to send the report to an e-mail recipient or to a Microsoft Word or PowerPoint file, print the report, save it to a file, or adjust the font size.

Named Selection Toolbar The Named Selection toolbar allows you to select, add to, and remove items from existing user-defined named selections as well as modify the visibility and suppression states. The specific features available on the toolbar are described in the Using Named Selections via the Toolbar (p. 446) section.

Unit Conversion Toolbar The Unit Conversion toolbar is a built-in conversion calculator. It allows conversion between consistent unit systems. The Units menu sets the active unit system. The status bar shows the current unit system. The units listed in the toolbar and in the Details view are in the proper form (i.e. no parenthesis). The Unit Conversions toolbar is hidden by default. To see it, select View> Toolbars> Unit Conversion.

Graphics Options Toolbar

The Graphics Options toolbar provides quick access to features that are useful for controlling the graphical display of models. The toolbar is displayed by default, but can be hidden (or turned back on) by selecting View> Toolbars> Graphics Options. Refer to the table below for the specific actions you can take using this toolbar’s features.

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Application Interface Icon Button

Tool Tip Name Displayed

Description

Toggle Show Vertices On or Off

Enabling the Show Vertices button highlights all vertices on the model. This feature is especially useful when examining complex assemblies where vertices might normally be hidden from view. It can also be used to ensure that edges are complete and not segmented unintentionally. Enabling Wireframe mode displays the model in the Geometry window with a wireframe display rather than a shaded one (recommended for seeing gaps in surface bodies). The Wireframe option not only applies to geometry, mesh, or named selections displayed as a mesh, but extends to probes, results, and variable loads to enable a better understanding of regions of interest.

Wireframe Mode On or Off

When Wireframe mode is set, just the exterior faces of the meshed models are shown, not the interior elements. Note that when this option is on, green scoping is not drawn on probes. Also, elements are shown on probes and results, whereas the outline of the mesh is shown on isoline contour results. Selecting any of the edges options on contour results automatically closes Wireframe mode.

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Show Mesh

Enabling the Show Mesh button displays the model’s mesh regardless of the selected tree object. When enabled, to make sure that Annotations display properly, also turn on Wireframe mode. See Note below.

Show all Coordinate Systems

Enabling the Show all Coordinate Systems button displays all available coordinate systems associated with the model – default as well as user defined.

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Toolbars Icon Button

Tool Tip Name Displayed

Description

Random Colors

By default, all loads, supports, named selections, and contacts are shown in one color. Enabling the Random Colors button displays each distinct load, support, named selection, or contact with a random color at each redraw.

Annotation Preferences

Displays the Annotation Preferences dialog box, in which you set preferences for annotation display.

Note As illustrated below, annotations may not always display properly when the Show Mesh button is activated. Turning on Wireframe mode accurately displays Annotations when Show Mesh is selected.

Edge Graphics Options

The Edge Graphics Options toolbar is a graphical display feature used for displaying the edges on a model; their connectivity and how they are shared by faces. The toolbar is displayed by default, but can be hidden (or turned back on) by selecting View>Toolbars>Edge Graphics Options. Refer to the table below for the specific actions you can take using this toolbar’s features. Also see the Assemblies of Surface Bodies (p. 376) section for details. Icon Button

Tool Tip Name Displayed

Description By Body Color: Displays body colors to represent boundary edges.

Edge Coloring

By Connection: Displays five different colors corresponding to five different categories of connectivity. The categories are: free (blue), single (red), double (black), triple (pink) and multiple (yellow). Free means that the edge is not shared by any faces. Single means that the edge is shared by one face and so on. The color scheme is also displayed in the Edge/Face Connectivity legend.

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Application Interface Icon Button

Tool Tip Name Displayed

Description Black: Turns off the edge/face connectivity display. The entire model is displayed in black. Hide Free: Hides only edges not shared by any faces.

Free

Show Free: Displays only edges not shared by any faces. Thick Free: Displays only edges not shared by any faces at a different edge thickness compared to the rest of the model. Hide Single: Hides only edges that are shared by one face.

Single

Show Single: Displays only that are shared by one face. Thick Single: Displays only edges that are shared by one face at a different edge thickness compared to the rest of the model. Hide Double: Hides only edges that are shared by two faces.

Double

Show Double: Displays only that are shared by two faces. Thick Double: Displays only edges that are shared by two faces at a different edge thickness compared to the rest of the model. Hide Triple: Hides only edges that are shared by three faces.

Triple

Show Triple: Displays only that are shared by three faces. Thick Triple: Displays only edges that are shared by three faces at a different edge thickness compared to the rest of the model. Hide Multiple: Hides only edges that are shared by more than three faces.

Multiple

Edge Direction

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Show Multiple: Displays only that are shared by more than three faces. Thick Multiple: Displays only edges that are shared by more than three faces at a different edge thickness compared to the rest of the model. Displays model edge directions. The direction arrow appears at the midpoint of the edge. The size of

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Interface Behavior Based on License Levels Icon Button

Tool Tip Name Displayed

Description the arrow is proportional to the edge length.

Edges Joined by Mesh Connection

Display the edges using coloring schema, by taking into account the mesh connection information.

For annotations scoped to lines (for example, annotations representing loads, Thicken annotations scoped named selections, point masses, and so to lines on), enabling this button thickens these lines so they are more easily identifiable on the screen.

Note The following restrictions apply when using the Edge Graphics Options functions on the mesh, as compared to their use on geometry: • Not all the buttons/options are functional, for example, Double always displays thin black lines. The width of the colored lines cannot be changed. They are always thick. • During slicing, the colors of shared element edges are not drawn. They display as black and appear only when the selected section plane is losing focus in the slice tool pane.

Tree Filter Toolbar The Tree Filter toolbar is used to filter the tree for objects or tags matching specified search terms For information on using this toolbar, see Filtering the Tree (p. 9). The Tree Filter toolbar is shown by default. To hide it, select View> Toolbars> Tree Filter. Mechanical will restore your last setting with each new session.

Interface Behavior Based on License Levels The licensing level that you choose automatically allows you to exercise specific features and blocks other features that are not allowed. Presented below are descriptions of how the interface behaves when you attempt to use features not allowed by a license level. • If the licensing level does not allow an object to be inserted, it will not show in the Insert menus. • If you open a database with an object that does not fit the current license level, the database changes to «read-only» mode. • If a Details view option is not allowed for the current license level, it is not shown.

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Application Interface • If a Details view option is not allowed for the current license level, and was preselected (either through reopening of a database or a previous combination of settings) the Details view item will become invalid and shaded yellow.

Note When you attempt to add objects that are not compatible with your current license level, the database enters a read-only mode and you cannot save data. However, provided you are using any license, you can delete the incompatible objects, which removes the read-only mode and allows you to save data and edit the database.

Environment Filtering The Mechanical interface includes a filtering feature that only displays model-level items applicable to the particular analysis type environments in which you are working. This provides a simpler and more focused interface. The environment filter has the following characteristics: • Model-level objects in the tree that are not applicable to the environments under a particular model are hidden. • The user interface inhibits the insertion of model-level objects that are not applicable to the environments of the model. • Model-level object properties (in the Details view of objects) that are not applicable to the environments under the model are hidden. The filter is enabled by default when you enter the Mechanical application. You can disable the filter by highlighting the Model object, clicking the right mouse button, and choosing Disable Filter from the context menu. To enable the filter, repeat this procedure but choose Auto Filter from the context menu. You can also check the status of the filter by highlighting the Model object and in the Details view, noting whether Control under Filter Options is set to Enabled or Disabled. The filter control setting (enabled or disabled) is saved when the model is saved and returns to the same state when the database is resumed.

Customizing the Mechanical Application Specifying Options (p. 74) Setting Variables (p. 85) Using Macros (p. 86)

Specifying Options You can control the behavior of functions in the Mechanical application through the Options dialog box. To access the Mechanical application options: 1. From the main menu, choose Tools> Options. An Options dialog box appears and the Mechanical application options are displayed on the left. 2. Click on a specific option.

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Customizing the Mechanical Application 3. Change any of the option settings by clicking directly in the option field on the right. You will first see a visual indication for the kind of interaction required in the field (examples are drop-down menus, secondary dialog boxes, direct text entries). 4. Click OK.

Note • If you enter a number with the thousand separator (in English, the thousand separator is a comma [,]), you will be asked to confirm the entry before it is accepted. For example, if you enter “2,300”, you receive a message stating the following: “Entered value is 2,300. Do you want to accept the correction proposed below? 2300 To accept the correction, click Yes. To close this message and correct the number yourself, click No. • Option settings within a particular language are independent of option settings in another language. If you change any options from their default settings, then start a new Workbench session in a different language, the changes you made in the original language session are not reflected in the new session. You are advised to make the same option changes in the new language session.

Mechanical Options The following Mechanical application options appear in the Options dialog box: Connections Convergence Import Export Fatigue Frequency Geometry Graphics Miscellaneous Report Analysis Settings and Solution Visibility Wizard

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Connections The Auto Detection category allows you to change the default values in the Details view for the following:

Note The auto contact detection on geometry attach can be turned on/off from the Workbench Options dialog box for the Mechanical application. See the Mechanical part of the Setting ANSYS Workbench Options section of the Help. • Tolerance: Sets the default for the contact detection slider; i.e., the relative distance to search for contact between parts. The higher the number, the tighter the tolerance. In general, creating contacts at a tolerance of 100 finds less contact surfaces than at 0. The default is 0. The range is from -100 to +100. • Face/Face: Sets the default preference1 (p. 76) for automatic contact detection between faces of different parts. The choices are Yes or No. The default is Yes. • Face/Edge: Sets the default preference1 (p. 76) for automatic contact detection between faces and edges of different parts. The choices are: – Yes – No (default) – Only Solid Body Edges – Only Surface Body Edges • Edge/Edge: Sets the default preference1 (p. 76) for automatic contact detection between edges of different parts. The choices are Yes or No. The default is No. • Priority: Sets the default preference1 (p. 76) for the types of contact interaction priority between a given set of parts. The choices are: – Include All (default) – Face Overrides – Edge Overrides • Revolute Joints: Sets the default preference for automatic joint creation of revolute joints. The choices are Yes and No. The default is Yes. • Fixed Joints: Sets the default preference for automatic joint creation of fixed joints. The choices are Yes and No. The default is Yes. 1

Unless changed here in the Options dialog box, the preference remains persistent when starting any Workbench project.

The Transparency category includes the following exclusive controls for this category. There are no counterpart settings in the Details view.

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Customizing the Mechanical Application • Parts With Contact: Sets transparency of parts in selected contact region so the parts are highlighted. The default is 0.8. The range is from 0 to 1. • Parts Without Contact: Sets transparency of parts in non-selected contact regions so the parts are not highlighted. The default is 0.1. The range is from 0 to 1. The Default category allows you to change the default values in the Details view for the following: • Type: Sets the definition type of contact. The choices are: – Bonded (default) – No Separation – Frictionless – Rough – Frictional • Behavior: Sets the contact pair. The choices are: – Program Controlled (default) – Asymmetric – Symmetric – Auto Asymmetric • Formulation: Sets the type of contact formulation method. The choices are: – Program Controlled (default) – Augmented Lagrange – Pure Penalty – MPC – Normal Lagrange • Update Stiffness: Enables an automatic contact stiffness update by the program. The choices are: – Program Controlled (default) – Never – Each Iteration – Each Iteration, Aggressive • Shell Thickness Effect (p. 508): This settings allows you to automatically include the thickness of surface bodies during contact calculations. The default setting is No. • Auto Rename Connections: Automatically renames joint, spring, contact region, and joint condition objects when Type or Scoping are changed. The choices are Yes and No. The default is Yes. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Convergence The Convergence category allows you to change the default values in the Details view for the following: • Target Change: Change of result from one adapted solution to the next. The default is 20. The range is from 0 to 100. • Allowable Change: This should be set if the criteria is the max or min of the result. The default is Max. The Solution category allows you to change the default values in the Details view for the following: • Max Refinement Loops: Allows you to change the number of loops. The default is 1. The range is from 1 to 10.

Import The Import category allows you to specify preferences for when you import data into Mechanical. Currently, these preferences are for importing delamination interfaces from the ANSYS Composite PrepPost (ACP) application. • Create Delamination Objects: This option controls the automatic creation of Interface Delamination objects in Mechanical when importing layered section data from ACP. When Interface layers are specified in ACP, Interface Delamination objects corresponding to Interface Layers are automatically inserted into the Mechanical Tree Outline under the Fracture object. The default setting is Yes. • Delete Invalid Objects: This option controls the deletion of Invalid Interface Delamination objects scoped to Interface Layers from ACP. When an Interface Layer specified in ACP is deleted, the corresponding Interface Delamination object is deleted in Mechanical when the project is refreshed. The default settings is No. This default setting suppresses invalid objects instead of automatically deleting them.

Export The Export category provides the following exclusive settings. There are no counterpart settings in the Details view. • Automatically Open Excel: Excel will automatically open with exported data. The default is Yes. • Include Node Numbers: Node numbers will be included in exported file. The default is Yes. • Include Node Location: Node location can be included in exported file. The default is No.

Fatigue The General category allows you to change the default values in the Details view for the following: • Design Life: Number of cycles that indicate the design life for use in fatigue calculations. The default is 1e9. • Analysis Type: The default fatigue method for handling mean stress effects. The choices are: – SN — None (default) – SN — Goodman – SN — Soderberg 78

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Customizing the Mechanical Application – SN — Gerber – SN — Mean Stress Curves The Goodman, Soderberg, and Gerber options use static material properties along with S-N data to account for any mean stress while Mean-Stress Curves use experimental fatigue data to account for mean stress. The Cycle Counting category allows you to change the default values in the Details view for the following: • Bin Size: The bin size used for rainflow cycle counting. A value of 32 means to use a rainflow matrix of size 32 X 32. The default is 32. The range is from 10 to 200. The Sensitivity category allows you to change the default values in the Details view for the following: • Lower Variation: The default value for the percentage of the lower bound that the base loading will be varied for the sensitivity analysis. The default is 50. • Upper Variation: The default value for the percentage of the upper bound that the base loading will be varied for the sensitivity analysis. The default is 150. • Number of Fill Points: The default number of points plotted on the sensitivity curve. The default is 25. The range is from 10 to 100. • Sensitivity For: The default fatigue result type for which sensitivity is found. The choices are: – Life (default) – Damage – Factor of Safety

Frequency The Frequency category allows you to change the default values in the Details view for the following: • Max Number of Modes: The number of modes that a newly created frequency branch will contain. The default is 6. The range is from 1 to 200. • Limit Search to Range: You can specify if a frequency search range should be considered in computing frequencies. The default is No. • Min Range (Hz): Lower limit of search range. The default is 0. • Max Range (Hz): Upper limit of search range. The default is 100000000. • Cyclic Phase Number of Steps: The number of intervals to divide the cyclic phase range (0 — 360 degrees) for frequency couplet results in cyclic modal analyses.

Geometry The Geometry category allows you to change the default values in the Details view for the following: • Nonlinear Material Effects: Indicates if nonlinear material effects should be included (Yes), or ignored (No). The default is Yes. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Application Interface • Thermal Strain Calculation: Indicates if thermal strain calculations should be included (Yes), or ignored (No). The default is Yes.

Note This setting applies only to newly attached models, not to existing models. The Material category provides the setting Prompt for Model Refresh on Material Edit. This setting relates to the material Assignment property. If you choose to edit a material or create/import a new material via this property, the application displays a message (illustrated below) reminding you to refresh the Model cell in the Workbench Project Schematic. The default setting is Yes. The message in Mechanical provides you with the option to not show the message again. This option is in addition to this method of changing this setting to No.

Graphics The Default Graphics Options category allows you to change the default values in the Details view for the following: • Max Number of Annotations to Show: A slider that specifies the number of annotations that are shown in the legend and the graphics. The possible values range from 0 to 50. The default is 10. • Show Min Annotation: Indicates if Min annotation will be displayed by default (for new databases). The default is No. • Show Max Annotation: Indicates if Max annotation will be displayed by default (for new databases). The default is No. • Contour Option: Selects default contour option. The choices are: – Smooth Contour – Contour Bands (default) – Isolines – Solid Fill • Flat Contour Tolerance: Flat contours (no variation in color) display if the minimum and maximum results values are equal. The comparison of the minimum and maximum values is made using scientific notation with the number of significant digits to the right of the decimal point as specified with the flat contour tolerance setting (3 to 9). Increasing this tolerance allows you to display contours for an otherwise too narrow range of values. Decreasing this tolerance prevents insignificant range variations from being contoured. This setting has a default value of 3.

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Customizing the Mechanical Application • Edge Option: Selects default edge option. The choices are: – No Wireframe (default) – Show Undeformed Wireframe – Show Undeformed Model – Show Elements • Highlight Selection: Indicates default face selection. The choices are: – Single Side (default) – Both Sides • Number of Circular Cross Section Divisions: Indicates the number of divisions to be used for viewing line body cross sections for circular and circular tube cross sections. The range is adjustable from 6 to 360. The default is 16. • Mesh Visibility: Indicates if mesh is automatically displayed when the Mesh object is selected in the Tree Outline, or if it’s only displayed when you select the Show Mesh button. The default is Automatic.

Miscellaneous The Miscellaneous category allows you to change the default values in the Details view for the following: • Load Orientation Type: Specifies the orientation input method for certain loads. This input appears in the Define By option in the Details view of the load, under Definition. – Vector (default) – Component The Image category includes the following exclusive controls for this category. There are no counterpart settings in the Details view. • Image Transfer Type: Defines the type of image file created when you send an image to Microsoft Word or PowerPoint, or when you select Print Preview. The choices are: – PNG (default) – JPEG – BMP The Post Processing (MAPDL Only) category includes the following controls for results files written by the Mechanical APDL solver: • Result File Caching: By holding substantial portions of a file in memory, caching reduces the amount of I/O associated with result file reading. The cache can, however, reduce memory that would otherwise be used for other solutions. The choices are: – System Controlled (default): The operating system determines whether or not the result file is cached for reading.

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Application Interface – Off: There is no caching during the reading of the result file. – Programmed Controlled: The Mechanical application determines whether or not the result file is cached for reading. The Save Options category includes the following controls for this category. • Save Project Before Solution: Sets the Yes / No default for the Save Project Before Solution setting located in the Project Details panel. Although you can set the default here, the solver respects the latest Save Project Before Solution setting in the Details panel. The default for this option is No. Selecting Yes saves the entire project immediately before solving (after any required meshing). If the project had never been previously saved, you can now select a location to save a new file. • Save Project After Solution: Sets the Yes / No default for the Save Project After Solution setting in the Project Details panel. The default for this option is No Selecting Yes Saves the project immediately after solving but before postprocessing. If the project had never been previously saved, nothing will be saved.

Note The save options you specify on the Project Details panel override the options specified in the Options dialog box and will be used for the current project.

Report The Figure Dimensions (in Pixels) category includes the following controls that allow you to make changes to the resolution of the report for printing purposes. • Chart Width — Default value equals 600 pixels. • Chart Height — Default value equals 400 pixels. • Graphics Width — Default value equals 600 pixels. • Graphics Height — Default value equals 500 pixels. • Graphics Resolution — Resolution values include: – Optimal Onscreen Display (1:1) – Enhanced Print Quality (2:1) – High-Resolution Print Quality (4:1) The Customization category includes the following controls: • Maximum Number of Table Columns: (default = 6 columns) Changes the number of columns used when a table is created. • Merge Identical Table Cells: merges cells that contain identical values. The default value is Yes. • Omit Part and Joint Coordinate System Tables: chooses whether to include or exclude Coordinate System data within the report. This data can sometimes be cumbersome. The default value is Yes.

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Customizing the Mechanical Application • Include Figures: specifies whether to include Figure objects as pictures in the report. You may not want to include figures in the report when large solved models or models with a mesh that includes many nodes and elements are involved. In these cases, figure generation can be slow, which could significantly slow down report generation. The default value is Yes.

Note This option applies only to Figure objects as pictures. Graph pictures, Engineering Data graphs, and result graphs (such as phase response in a harmonic analysis) are not affected and will appear regardless of this option setting.

• Custom Report Generator Folder: reports can be run outside of the Workbench installation directory by copying the Workbench Report2006 folder to a new location. Specify the new folder location in this field. See the Customize Report Content section for more information.

Analysis Settings and Solution The Solver Controls category allows you to change the default values in the Details view for the following: • Solver Type: Specifies which ANSYS solver will be used. The choices are: – Program Controlled (default) – Direct – Iterative • Use Weak Springs: specifies whether weak springs are added to the model. The Programmed Controlled setting automatically allows weak springs to be added if an unconstrained model is detected, if unstable contact exists, or if compression only supports are active. The choices include: – Program Controlled (default) – On – Off The Output Controls category allows you to change the default values in the Details view for the following: • Stress (Default setting = Yes) • Strain (Default setting = Yes) • Nodal Forces (Default setting = No) • Contact Miscellaneous (Default setting = No) • General Miscellaneous (Default setting = No) • Calculate Reactions (Default setting = Yes) • Calculate Thermal Flux (Default setting = Yes) Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Application Interface Output Controls (Modal): this category allows you to change the default value in the Details for the Store Modal Results option. The default setting is Program Controlled. The Output Controls (Random Vibration) category allows you to change the default value in the Details view for the following: • Keep Modal Results: include or remove modal results from the result file of random vibration analysis. The default setting is No. • Calculate Velocity: Write Velocity results to the results file. The default setting is Yes. • Calculate Acceleration: Write Acceleration results to the results file. The default setting is Yes. The Restart Controls category allows you to change the default value in the Details view for the following: • Generate Restart Points: Program Controlled (default setting) automatically generates restart points. Additional options include Manual, that provides user-defined settings, and Off, which restricts the creation of new restart points. • Retain Files After Full Solve: when restart points are requested, the necessary restart files are always retained for an incomplete solve due to a convergence failure or user request. However, when the solve completes successfully, you have the option to request to either keep the restart points by setting this field to Yes, or to delete them by setting this field to No. You can control these settings in the Details view of the Analysis Settings object under Restart Controls (p. 644), or here under Tools> Options in the Analysis Settings and Solution preferences list. The setting in the Details view overrides the preference setting. The Solution Information category allows you to change the default value in the Details view for the following: • Refresh Time: specifies how often any of the result tracking items under a Solution Information object get updated while a solution is in progress. The default is 2.5 s. • Activate FE Connection Visibility: specifies the value of the Activate Visibility property. The default setting is Yes. The Solution Settings category allows you to set the default value in the Details view for the following: • Results Availability: specifies what results to allow under the Solution object in Design Assessment systems when the Solution Selection object allows combinations. The default is Filter Combination Results. The Analysis Data Management category allows you to set the default value in the Details view for the Save MAPDL db control. Values are No (default) or Yes. The setting of the Future Analysis control (see Analysis Data Management Help section) can sometimes require the db file to be written. In this case, the Save MAPDL db control is automatically set to Yes.

Visibility This selection and category provides the Part Mesh Statistics setting. This setting allows you to display or hide the Statistics category in the Details view for Body and Part objects.

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Customizing the Mechanical Application

Wizard The Wizard Options category includes the following exclusive controls for this category. There are no counterpart settings in the Details view. • Default Wizard: This is the URL to the XML wizard definition to use by default when a specific wizard isn’t manually chosen or automatically specified by a simulation template. The default is StressWizard.xml. • Flash Callouts: Specifies if callouts will flash when they appear during wizard operation. The default is Yes. The Skin category includes the following exclusive controls for this category. There are no counterpart settings in the Details view. • Cascading Style Sheet: This is the URL to the skin (CSS file) used to control the appearance of the Mechanical Wizard. The default is Skins/System.css. The Customization Options category includes the following exclusive controls for this category. There are no counterpart settings in the Details view. • Mechanical Wizard URL: For advanced customization. See Appendix: Workbench Mechanical Wizard Advanced Programming Topics for details. • Enable WDK Tools: Advanced. Enables the Wizard Development Kit. The WDK adds several groups of tools to the Mechanical Wizard. The WDK is intended only for persons interested in creating or modifying wizard definitions. The default is No. See the Appendix: Workbench Mechanical Wizard Advanced Programming Topics for details.

Note • URLs in the Mechanical Wizard follow the same rules as URLs in web pages. • Relative URLs are relative to the location of the Mechanical Wizard URL. • Absolute URLs may access a local file, a UNC path, or use HTTP or FTP.

User Preferences File The Mechanical application stores the configuration information from the Options dialog box in a file called a User Preference File on a per user basis. This file is created the first time you start the Mechanical application. Its default location is: %APPDATA%\Ansys\v145\%AWP_LOCALE145%\dsPreferences.xml

Setting Variables Variables provide you the capability to override default settings. To set variables: 1.

Choose Variable Manager from the Tools menu.

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Right-click in the row to add a new variable.

3.

Enter a variable name and type in a value.

4.

Click OK. Variable name

Allowable Values

Description

DSMESH OUTPUT

filename

Writes mesher messages to a file during solve (default = no file written). If the value is a filename, the file is written to the temporary working folder (usually c:\temp). To write the file to a specific location, specify the full path.

DSMESH DEFEATUREPERCENT

a number between 1e-6 and 1e-3

Tolerance used in simplifying geometry (default = .0005).

Keep Modal Results

1

Set to 1 to include Modal analysis results in the result file for a Random Vibration Analysis.

Status The status box indicates if a particular variable is active or not. Checked indicates that the variable is active. Unchecked indicates that the variable is available but not active. This saves you from typing in the variable and removing it.

Using Macros The Mechanical application allows you to execute custom functionality that is not included in a standard Mechanical application menu entry via its Run Macro feature. The functionality is defined in a macro a script that accesses the Mechanical application programming interface (API). Macros can be written in Microsoft’s JScript or VBScript programming languages. Several macro files are provided with the ANSYS Workbench installation under \ANSYS Inc\v150\AISOL\DesignSpace\DSPages\macros. Macros cannot currently be recorded from the Mechanical application. To access a macro from the Mechanical application: 1.

Choose Run Macro… from the Tools menu.

2.

Navigate to the directory containing the macro.

3.

Open the macro. The functionality will then be accessible from the Mechanical application.

Working with Graphics Here are some tips for working with graphics: • You can use the ruler, shown at the bottom of the Geometry window, to obtain a good estimate of the scale of the displayed geometry or results (similar to using a scale on a geographic map). The ruler is useful when setting mesh sizes. • You can rotate the view in a geometry selection mode by dragging your middle mouse button. You can zoom in or out by rolling the mouse wheel.

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Working with Graphics • Hold the control key to add or remove items from a selection. You can paint select faces on a model by dragging the left mouse button. • You can pan the view by using the arrow keys. You can rotate the view by using the control key and arrow keys. • Click the interactive Controlling the Viewing Orientation (p. 113) to quickly change the graphics view. • Use the stack of rectangles in the lower left corner of the Geometry Window (p. 20) to select faces hidden by your current selection. • To rotate about a specific point in the model, switch to rotate mode and click the model to select a rotation point. Click off the model to restore the default rotation point. • To multi-select one or more faces, hold the Ctrl key and click the faces you wish to select, or use Box Select to select all faces within a box. The Ctrl key can be used in combination with Box Select to select faces within multiple boxes. • Click the Using Viewports (p. 106) icon to view up to four images in the Geometry Window (p. 20). • Controls are different for Graphs & Charts. More information is available in the following topics: Selecting Geometry Selecting Nodes Selecting Elements Defining Direction Using Viewports Controlling Graphs and Charts Managing Graphical View Settings Creating Section Planes Controlling the Viewing Orientation Viewing Annotations Controlling Lighting Inserting Comments, Images, and Figures

Selecting Geometry This section discusses cursor modes and how to select and pick geometry in the Geometry window. It includes information on the following: Pointer Modes (p. 88) Highlighting (p. 88) Picking (p. 88) Blips (p. 89) Painting (p. 89) Depth Picking (p. 89) Selection Filters (p. 90) Extend Selection Menu (p. 91) Selection Modes (p. 90) For Help on how to select mesh nodes and elements, see the Selecting Nodes and Selecting Elements sections. Many of the same selection and picking tools are employed for mesh selections.

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Pointer Modes The pointer in the graphics window is always either in a picking filter mode or a view control mode. When in a view control mode the selection set is locked. To resume the selection, repress a picking filter button. The Graphics Toolbar offers several geometry filters and view controls as the default state, for example, face, edge, rotate, and zoom. If a Geometry field in the Details View (p. 11) has focus, inappropriate picking filters are automatically disabled. For example, a pressure load can only be scoped to faces. If the Direction field in the Details View (p. 11) has focus, the only enabled picking filter is Select Direction. Select Direction mode is enabled for use when the Direction field has focus; you never choose Select Direction manually. You may manipulate the view while selecting a direction. In this case the Select Direction button allows you to resume your selection.

Highlighting Hovering your cursor over a geometry entity highlights the selection and provides visual feedback about the current pointer behavior (e.g. select faces) and location of the pointer (e.g. over a particular face). As illustrated here, the face edges are highlighted in colored dots.

Picking A pick means a click on visible geometry. A pick becomes the current selection, replacing previous selections. A pick in empty space clears the current selection. By holding the Ctrl key down, you can add additional selections or remove existing selections. Clicking in empty space with Ctrl depressed does not clear current selections. For information on picking nodes, see Selecting Nodes (p. 96).

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Working with Graphics

Blips As illustrated below, when you make a selection on a model, a crosshair “blip” appears.

The blip serves to: • Mark a picked point on visible geometry. • Represent a ray normal to the screen passing through all hidden geometry. When you make multiple selections using the Ctrl key, the blip is placed at the last selection entity. Clicking in empty space clears your current selection, but the blip remains in its last location. Once you have cleared a selection, hold the Ctrl key down and click in clear space again to remove the blip.

Note This is important for depth picking, a feature discussed below.

Painting Painting means dragging the mouse on visible geometry to select more than one entity. A pick is a trivial case of painting. Without holding the Ctrl key down, painting picks all appropriate geometry touched by the pointer.

Depth Picking Depth Picking allows you to pick geometry through the Z-order behind the blip. Whenever a blip appears above a selection, the graphics window displays a stack of rectangles in the lower left corner. The rectangles are stacked in appearance, with the topmost rectangle representing the visible (selected) geometry and subsequent rectangles representing geometry hit by a ray normal to the screen passing through the blip, front to back. The stack of rectangles is an alternative graphical

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Application Interface display for the selectable geometry. Each rectangle is drawn using the same edge and face colors as its associated geometry. Highlighting and picking behaviors are identical and synchronized for geometry and its associated rectangle. Moving the pointer over a rectangle highlights both the rectangle its geometry, and vice versa. Ctrl key and painting behaviors are also identical for the stack. Holding the Ctrl key while clicking rectangles picks or unpicks associated geometry. Dragging the mouse (Painting (p. 89)) along the rectangles picks geometry front-to-back or back-to-front.

Selection Filters The mouse pointer in the graphics window is either in a picking filter mode or a view control mode. A depressed button in the graphics toolbar indicates the current mode. Filter

Behavior

Vertices

Vertices are represented by concentric circles about the same size as a blip. The circumference of a circle highlights when the pointer is within the circle.

Edges

Painting may be used to pick multiple edges or to «paint up to» an edge (to avoid tediously positioning the pointer prior to clicking).

Faces

Allows selection of faces. Highlighting occurs by dotting the banding edges of the face.

Bodies

Picking and painting: select entire bodies. Highlighted by drawing a bounding box around the body. The stack shows bodies hidden behind the blip (useful for selecting contained bodies).

Selection Modes The Select Mode toolbar button allows you to select items designated by the Selection Filters through the Single Select or Box Select drop-down menu options. • Single Select (default): Click on an item to select it. • Box Select: Define a box that selects filtered items. When defining the box, the direction that you drag the mouse from the starting point determines what items are selected, as shown in the following figures:

– Dragging to the right to form the box selects entities that are completely enclosed by the box. – Visual cue: 4 tick marks completely inside the box.

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Working with Graphics

– Dragging to the left to form the box selects all entities that touch the box. – Visual cue: 4 tick marks that cross the sides of the box. • Box Volume Select: Available for node-based Named Selections only. Selects all the surface and internal node within the box boundary across the cross-section. The line of selection is normal to the screen. • Lasso Select: Available for node-based Named Selections only. Selects surface nodes that occur within the shape you define. • Lasso Volume Select: Available for node-based Named Selections only. Selects nodes that occur within the shape you define.

Note Selection shortcuts: • You can use the Ctrl key for multiple selections in both modes. • You can change your selection mode from Single Select to Box Select by holding the right mouse button and then clicking the left mouse button. • Given a generated mesh and that the Mesh Select option is active, holding the right mouse button and then clicking the left mouse button scrolls through the available selection options (single section, box selection, box volume, lasso, lasso volume).

Extend Selection Menu The Extend Selection drop-down menu is enabled only for edge or face selection mode and only with a selection of one or more edges or faces. The following options are available in the drop-down menu: • Extend to Adjacent – For faces, Extend to Adjacent searches for faces adjacent to faces in the current selection that meet an angular tolerance along their shared edge.

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Application Interface

Single face selected in part on the left.

Additional adjacent faces selected after Extend to Adjacent option is chosen.

– For edges, Extend to Adjacent searches for edges adjacent to edges in the current selection that meet an angular tolerance at their shared vertex.

Single edge selected in part on the left.

Additional adjacent edges selected after Extend to Adjacent option is chosen.

• Extend to Limits – For faces, Extend to Limits searches for faces that are tangent to the current selection as well as all faces that are tangent to each of the additional selections within the part. The selections must meet an angular tolerance along their shared edges.

Single face selected in part on the left.

Additional tangent faces selected after Extend to Limits option is chosen.

– For edges, Extend to Limits searches for edges that are tangent to the current selection as well as all edges that are tangent to each of the additional selections within the part. The selections must meet an angular tolerance along their shared vertices.

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Single edge selected in part on the left.

Additional tangent edges selected after Extend to Limits option is chosen.

• Extend to Instances (available only if CAD pattern instances are defined in the model): When a CAD feature is repeated in a pattern, it produces a family of related topologies (for example, vertices, edges, faces, bodies) each of which is named an «instance». Using Extend to Instances, you can use one of the instances to select all others in the model. As an example, consider three parts that are instances of the same feature in the CAD system. First select one of the parts.

Then, choose Extend to Instances. The remaining two part instances are selected.

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See CAD Instance Meshing for further information. • Extend to Connection – As described in Define Connections (p. 132), connections can be contact regions, joints, mesh connections, and so on. Available for faces only, the Extend to Connection option is especially useful for assembly meshing as an aid in picking faces related to flow volumes. For example, if you are using a Fluid Surface object to help define a virtual body, you can generate connections, pick one face on each body of the flow volume, and then select Extend to Connection. As a result, the faces related to the flow volume are picked to populate the Fluid Surface object. Extend to Connection searches for faces that are adjacent to the current selection as well as all faces that are adjacent to each of the additional selections within the part, up to and including all connections on the selected part. This does not include all faces that are part of a connection—it includes only those faces that are part of a connection and are also on the selected part. If an edge used by a connection is encountered, the search stops at the edge; a face across the edge is not selected. If there are no connections, all adjacent faces are selected. If the current selection itself is part of a connection, it remains selected but the search stops.

Note → Virtual Body and Fluid Surface objects are fluids concepts, and as such they are not supported by Mechanical solvers. → The extent of the faces that will be included depends greatly on the current set of connections, as defined by the specified connections criteria (for example, Connection Type, Tolerance Value, and so on). By modifying the criteria and regenerating the connections, a different set of faces may be included. Refer to Common Connections Folder Operations for Auto Generated Connections (p. 501) for more information. → The figures below illustrate simple usage of the Extend to Connection option. Refer to Defining Virtual Bodies in the Meshing help for a practical example of how you can use

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Working with Graphics the Extend to Connection option and virtual bodies together to solve assembly meshing problems.

Single face selected in part.

Single face selected in part. In this example, a multiple edge to single face connection is defined.

Additional connected faces selected after Extend to Connection option is chosen.

Additional connected faces selected after Extend to Connection option is chosen. When the connection is encountered, search stops at edge.

For all options, you can modify the angle used to calculate the selection extensions in the Workbench Options dialog box setting Extend Selection Angle Limit under Graphics Interaction.

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Selecting Nodes As with geometry selection, you use many of the same selection and picking tools for mesh node selections. Once you have generated the mesh on your model, you use picking tools to select individual or multiple nodes on a mesh. You use node selections to define objects such as a node-based coordinate system or node-based Named Selections as well as examining solution information about your node selections. This section describes the steps to perform node selections on a mesh. Additional topics included in this section, as show below, cover additional uses for the node selection capability. Node Selection (p. 96) Selection Modes for Node Selection (p. 97) View Node Information (p. 98) Select Mesh Nodes on a Result Contour (p. 99) Also see the following sections for the steps to create node-based coordinate systems and Named Selections. Creating a Coordinate System by Direct Node Selection Specifying Named Selections by Direct Node Selection

Node Selection To select individual nodes: 1.

Generate a mesh by highlighting the Mesh object and clicking the Generate Mesh button.

2.

From the Select Type list, choose Select Mesh.

3.

Choose the appropriate selection tool in the Select Mode list. For more information on the node-based selection modes, see Selection Modes for Node Selection (p. 97).

Note • The Vertex geometry selection option is the only selection option available to pick nodes. • When working with Line Bodies: Nodes can be selected using volume selection modes only (Box Volume Select or Lasso Volume Select). • When working with Line Bodies and Surface Bodies: it is recommended that you turn off the Thick Shells and Beams option (View>Thick Shells and Beams). This option changes the graphical display of the model’s thickness and as a result can affect how your node selections are displayed.

4.

Select individual nodes or define the shape to select nodes. You can now define a coordinate system or named selection from selected nodes.

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Selection Modes for Node Selection Selects individual nodes or a group of nodes on the surface. Single Select Selects all the surface nodes within the box boundary for all the surfaces oriented toward the screen.

Box Select

Selects all the surface and internal nodes within the box boundary across the crosssection. The line of selection is normal to the screen.

Box Volume Select

Is similar to the Box Select mode. Selects surface nodes that occur within the shape you define for surfaces oriented toward the screen.

Lasso Select

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Application Interface Similar to Box Volume Select mode. Selects the nodes that occur within the shape you define.

Lasso Volume Select

Tip • To select multiple nodes, press the Ctrl key or press the left mouse and then drag over the surface. You can also create multiple node groups at different locations using the Ctrl key. • To select all internal and surface nodes, use the Box Volume Select or Lasso Select tool and cover the entire geometry within the selection tool boundary.

View Node Information You can view information such as the location of each selected node and a summary of the group of nodes in the Selection Information window. A brief description of the selected nodes is also available on the Status Bar of the application window. To view node id and location information: 1. Select the nodes you want to include in a Named Selection. 2. Click View>Windows >Selection Information The following options are available as drop-down menu items in the Selection Information window. Selection Information Field

Description

Coordinate System

Updates the X, Y, and Z information based on the selected coordinate system.

Show Individual and Summary

Shows both the node Summary and information on each node.

Show Individual

Shows information related to each node.

Show Summary

Shows only a summary of selected nodes.

For more information see the Selection Information Toolbar section.

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Select Mesh Nodes on a Result Contour Nodes (from the original mesh) can be selected even if they don’t have values for the selected result, as in a path or surface scoped result.

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Application Interface The positions of selected nodes reported in the Selection Information window are those from nondeformed mesh.

Note If the graphics expansion is used (for shells and cyclic expansion, for example), the selection will work on the expanded graphics, while the reported node ID and position will be those in the non-expanded mesh. To eliminate confusion, switch the expansion off.

Creating a Coordinate System by Direct Node Selection You can select one or more nodes and then create a coordinate system directly in the Graphics window. The new coordinate system is created at the location of the selected node or the centroid of multiple nodes using the (X, Y, Z) locations, rather than the nodes themselves, to ensure that the location does not change upon re-meshing. To create a coordinate system from nodes in the Graphics window: 1.

Select one or more nodes as discussed in Selecting Nodes (p. 96).

2.

Right-click and select Create Coordinate System. A new coordinate system is created at the location of the selected node or the centroid of multiple nodes.

Note The mesh is not shown after coordinate system creation. To view the mesh again, from the Tree Outline, select Mesh.

If you re-mesh the body at this point, you will see that the coordinate system remains in the same location, as it is based on node location rather than node number.

Creating an Aligned Coordinate System You can also select an individual node and create an aligned coordinate system on a solved vector principal stress or strain result.

Note While you cannot create an aligned coordinate system based on multiple nodes, you can create a local coordinate system at the centroid with an axis oriented in the direction of the global coordinate system. To create an aligned coordinate system: 1.

From the Tree Outline, select a Vector Principal Stress or Vector Principal Strain result.

2.

Select a single node using the method outlined in Selecting Nodes (p. 96).

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Right-click in the Graphics window and select Create Aligned Coordinate System. A coordinate system is created. The Y-axis of the local coordinate system is oriented in the direction of S1 (direction of max. principal stress).

Note Vector Principal Stress and Vector Principal Strain results cannot be applied to line bodies or a node located on a line body. As a result, any automatically generated (aligned) coordinate system would be incorrect.

Specifying Named Selections by Direct Node Selection You create node-based Named Selections in the graphical viewer by scoping selections to single nodes, a group of surface nodes, or a group of nodes across a geometry cross-section.

Note You can make direct node selections when working with beams (line bodies) using the Worksheet. Direct graphical selection is also available but requires the appropriate selection tool (Select Mode) as described in the Node Selection section. To define node-based Named Selections: 1. Select individual nodes or define the shape to select nodes, as described in Selecting Nodes (p. 96).

Note For accuracy, ensure that the selected node lies within the scoped area of the result

2. In the Graphics window, right-click and select Create Named Selection. 3. Enter a name for the Named Selection and click OK.

Note • If you select a large number of nodes (order of magnitude: 10,000), you are prompted with a warning message regarding selection information time requirements. • Following a remesh or renumber, all nodes are removed from named selections. If named selections were defined with Scoping Method set to Worksheet and if the Generate on Remesh field was set to Yes in the Details view of the Named Selection folder, then the nodes are updated. Otherwise, node scoping does not occur and the named selection will be empty.

Selecting Elements Once you have generated the mesh on your model, you can select individual elements or multiple elements on a mesh using the appropriate selection filters (Body) and modes (Single Select and Box Select). The following topics describe element-based selection methods and features: Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Application Interface • Selecting Elements (p. 102) • Viewing Element Information (p. 103) • Specifying Element-Based Named Selections (p. 104)

Selecting Elements To select an element or elements: 1.

Generate the mesh by highlighting the Mesh object and clicking the Generate Mesh button.

2.

From the Select Type drop-down menu on the Graphics Toolbar, choose Select Mesh.

3.

Choose the desired selection tool from the Select Mode drop-down menu on the Graphics Toolbar. Active options include either Single Select or Box Selection.

4.

Select an individual element or multiple elements. To select multiple elements: • Hold the Ctrl key and click the desired elements individually. You can also deselect elements by holding down the Ctrl key clicking an already selected element. • Hold the left mouse button and drag the cursor across multiple elements. • Use the Box Select tool to select all elements within a box. The Ctrl key can also be used in combination with Box Select to select multiple boxes of elements.

Note • The Body Selection Filter must be used to pick elements. • As illustrated below for the example Named Selection, Graphically Selected Elements, when the Show Mesh feature is active, the elements of a named selection, or multiple named selections, are highlighted. Otherwise, the elements are drawn.

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Working with Graphics Show Mesh On

Show Mesh Off

• When working with Line Bodies and Surface Bodies: it is recommended that you turn off the Thick Shells and Beams option (View>Thick Shells and Beams). This option changes the graphical display of the model’s thickness and as a result can affect how your element selections are displayed. • The Select All (Ctrl+A) option is not available when selecting elements.

Viewing Element Information As illustrated below, you can view information about your element selections, such as Element Type, Element ID, as well as the body that the element is associated with using the Selection Information window. Once you have selected your desired element or elements, display the Selection Information window by selecting View>Windows >Selection Information.

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Note The Status Bar at the bottom of the application window also displays the number of elements you currently have selected. For additional information, see the Selection Information Toolbar section.

Specifying Element-Based Named Selections To create an element-based Named Selection: 1.

Select individual or multiple elements as described above.

2.

With your desired element selections highlighted, right-click the mouse and select Create Named Selection from the context menu.

3.

Enter a name for the Named Selection and click OK.

Element-based Named Selections are written into the MAPDL input file and this data can be used by the Command object for further processing.

Defining Direction Orientation may be defined by any of the following geometric selections: • A planar face (normal to). • A straight edge. • Cylindrical or revolved face (axis of ). • Two vertices. This section discusses the following topics: Direction Defaults (p. 105) Highlighting Geometry in Select Direction Mode (p. 105) Selecting Direction by Face (p. 105)

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Direction Defaults If you insert a load on selected geometry that includes both a magnitude and a direction, the Direction field in the Details view states a particular default direction. For example, a force applied to a planar face by default acts normal to the face. One of the two directions is chosen automatically. The load annotation displays the default direction.

Highlighting Geometry in Select Direction Mode Unlike other picking filters (where one specific type of geometry highlights during selection) the Select Direction filter highlights any of the following during selection: • Planar faces • Straight edges • Cylindrical or revolved faces • Vertices If one vertex is selected, you must hold down the Ctrl key to select the other. When you press the Ctrl key, only vertices highlight.

Selecting Direction by Face The following figure shows the graphic display after choosing a face to define a direction. The same display appears if you edit the Direction field later. • The selection blip indicates the hit point on the face. • Two arrows show the possible orientations. They appear in the lower left corner of the Geometry Window (p. 20) window.

If either arrow is clicked, the direction flips. When you finish editing the direction, the hit point (initially marked by the selection blip) becomes the default location for the annotation. If the object has a location as well as a direction (e.g. Remote Force), the location of the annotation will be the one that you specify, not the hit point.

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Note The scope is indicated by painting the geometry.

Using Viewports The Viewports toolbar button allows you to split the graphics display into a maximum of four simultaneous views. You can see multiple viewports in the Geometry Window (p. 20) window when any object in the tree is in focus except Project. You can choose one, horizontal, vertical, or four viewports. Each viewport can have separate camera angles, labels, titles, backgrounds, etc. Any action performed when viewports are selected will occur only to the active viewport. For example, if you animate a viewport, only the active viewport will be animated, and not the others.

A figure can be viewed in a single viewport only. If multiple viewports are created with the figure in focus, all other viewports display the parent of the figure.

Note Each viewport has a separate Section tool, and therefore separate Section Plane. The concept of copying a Section Plane from one window to the next does not exist. If you want Section Planes in a new window, you must create them in that window. Viewports are not supported in stepped analyses.

Controlling Graphs and Charts The following controls are available for Graphs/Charts for Adaptive Convergence (p. 1065), and Fatigue Results (p. 961) result items. Feature

Control

Pan

Right Mouse Button

Zoom

Middle Mouse Button

Box Zoom

Alt+Left Mouse Button

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Working with Graphics Rotate (3D only)

Left Mouse Button

Perspective Angle (3D only)

Shift+Left Mouse Button

Display Coordinates (2D only)

Ctrl+Left Mouse Button along graph line

Tips for working with graphs and charts: • Some features are not available for certain graphs. • Zoom will zoom to or away from the center of the graph. Pan so that your intended point of focus is in the center prior to zooming. • If the graph has a Pan/Zoom control box, this can be used to zoom (shrink box) or pan (drag box). • Double-clicking the Pan/Zoom control box will return it to its maximum size.

Managing Graphical View Settings Graphical view settings help to ensure a consistent graphical view. With the manage view functionality, you can save graphical views and return to a specific view at any time. To maintain a consistent model view list between multiple projects, you can export the graphical view list, and then import it into a different project. To view the Manage Views window, do one of the following: • In the toolbar, click the Manage Views

button.

• Select View>Windows>Manage Views. The Manage Views window opens. This section discusses the following topics: Creating a View Applying a View Renaming a View Deleting a View Replacing a Saved View Exporting a Saved View List Importing a Saved View List Copying a View to Mechanical APDL

Creating a View To save the current graphical view: 1.

In the Manage Views window, click the Create a View button. A new entry with the naming convention of “View #” is created in the Manage Views window. This entry is selected for renaming.

2.

If desired, enter a new name for the graphical view.

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Application Interface You can now return to this view at any time using this view entry.

Note You must save the project to save your created views in the Manage Views window.

Applying a View Saved graphical views are listed in the Manage Views window. You can return to a saved view at any time. To return to a saved graphical view: 1.

In the Manage Views window, select the view.

2.

Click the Apply View button.

The Geometry window reflects the saved graphical view.

Renaming a View To rename a saved graphical view: 1.

In the Manage Views window, select the view you want to rename.

2.

Click the Rename button, or press F2.

3.

Enter the new view name.

4.

Click the Apply button.

Deleting a View To delete a saved graphical view: 1.

In the Manage Views window, select the view you want to delete.

2.

Click the Delete button.

Replacing a Saved View To replace a saved view with the current graphical view: 1.

In the Manage Views window, select the view you want to update.

2.

Click the Replace saved view based on current graphics button.

Exporting a Saved View List You can export a saved graphical view list to an XML file. This file can then be imported into other projects. To export a saved view list:

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Working with Graphics 1.

In the Manage Views window, click the Export button. The Save As window appears.

2.

Navigate to the file directory where you want to store the XML file and enter the desired file name.

3.

Click Save.

Importing a Saved View List Saved view lists can be exported to XML files. You can then import a saved view list from an XML file to a different project. To import a saved graphical view list: 1.

In the Manage Views window, click the Import button. The Open window appears.

2.

Select the file you want to import.

3.

Click Open.

Copying a View to Mechanical APDL You can copy a saved graphical view as a Mechanical APDL command and insert the command into a Mechanical APDL file. The view in Mechanical APDL will then be consistent with the selected graphical view. To copy a graphical view to Mechanical APDL: 1.

In the Manage Views window, right-click a view and select Copy as MAPDL Command.

2.

Create or open an existing Commands (APDL) file.

3.

Paste the new Mechanical APDL command into the file. The settings structure is: /FOC /VIEW /ANG /DIST

4.

Select the Solve button, and the new view is available in the Commands (APDL) file.

Creating Section Planes The Section Plane feature creates cuts or slices on your model so that you can view internal geometry, mesh, and/or result displays. You can create as many as six Section Planes for a model. Once this maximum is met, the feature becomes disabled until less than six planes exist. Selecting the New Section Plane button ( ) in the Graphics toolbar initiates the function and displays the Section Planes window illustrated below.

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Application Interface

The Section Planes window provides the following capabilities. Icon Button

Application-Level Command New Section Plane Edit Section Plane Delete Section Plane Show Whole Elements (available when the Mesh object is selected)

Example 1: Section Plane Example As an example, consider the model shown below that is subjected to a horizontal and a vertical slice.

The mesh display will show 75% of the model while the geometry display will show 25% of the model.

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For additional information about the use of the Section Plane feature, see the following topics. Adding a Section Plane Using Section Planes Modifying a Section Plane Deleting a Section Plane

Adding a Section Plane To add a section plane: 1.

In the Section Planes window, click the New Section Plane button.

2.

Drag the mouse pointer across the geometry where you want to create a section plane.

The new section plane is listed in the Section Planes window with a default name of “Section Plane #.” The checkmark next to the plane’s name indicates it is an active section plane. 3.

You can construct additional Section Planes by clicking the New Section Plane button and dragging additional lines across the model. Note that activating multiple planes displays multiple sections:

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Application Interface

Using Section Planes • Maneuver between multiple planes by highlighting the plane names In the Section Planes window. • When you are on a Mesh display you can use the Show Whole Elements button to display the adjacent elements to the section plane which may be desirable in some cases. • For result displays, if the Section Plane feature is active, choosing Show Undeformed WireFrame from the Edges Options drop down menu on the Result Context Toolbar (p. 59) actually displays the wireframe with the deformations added to the nodes. This is intended to help you interpret the image when you drag the anchor across smaller portions of the model. • Unchecking all the planes effectively turns the Section Plane feature off.

Note that in incidences such as very large models where the accessible memory is exhausted, the New Section Plane tool will revert to a Hardware Slice Mode that prohibits visualization of the mesh on the cut-plane. The Section Plane acts differently depending if you are viewing a result, mesh, or geometry display. When viewing a result or a mesh, the cut is performed by a software algorithm. When viewing geometry, the cut is performed using a hardware clipping method. This hardware clipping cuts away the model in a subtractive method. The software algorithm cuts away the model but always starts with the whole model.

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Working with Graphics Geometry Display Example

Mesh Display Example

Note that the software algorithm caps the surfaces created by the section plane as opposed to the hardware clipping method. When capping, the software algorithm creates a visible surface at the intersection of the object and the section plane.»

Modifying a Section Plane To modify a section or capping plane: 1.

In the Section Planes window, select the plane you want to edit.

2.

Click the Edit Section Plane button. The section plane’s anchor appears.

3.

Drag the Section Plane or Capping Plane anchor to change the position of the plane.

You can click on the line on either side of the anchor to view the exterior on that side of the plane. The anchor displays a solid line on the side where the exterior is being displayed. Clicking on the same side a second time toggles between solid line and dotted line, i.e. exterior display back to section display. Note that for Geometry display, a capped view is always shown.

Deleting a Section Plane To delete a section or capping plane: 1.

In the Section Planes window, select the plane you want to delete.

2.

Click the Delete Section Plane button.

Controlling the Viewing Orientation The triad and rotation cursors allow you to control the viewing orientation as described below. Triad

• Located in lower right corner. • Visualizes the world coordinate system directions.

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Application Interface • Positive directions arrows are labeled and color-coded. Negative direction arrows display only when you hover the mouse cursor over the particular region. • Clicking an arrow animates the view such that the arrow points out of the screen. • Arrows and the isometric sphere highlight when you point at them. • Isometric sphere visualizes the location of the isometric view relative to the current view. • Clicking the sphere animates the view to isometric. Rotation Cursors

Click the Rotate button

to display and activate the following rotation cursors:

•

Free rotation.

•

Rotation around an axis that points out of the screen (roll).

•

Rotation around a vertical axis relative to the screen («yaw» axis).

•

Rotation around a horizontal axis relative to the screen («pitch» axis).

Cursor Location Determines Rotation Behavior The type of rotation depends on the starting location of the cursor. In general, if the cursor is near the center of the graphics window, the familiar 3D free rotation occurs. If the cursor is near a corner or edge, a constrained rotation occurs: pitch, yaw or roll. Specifically, the circular free rotation area fits the window. Narrow strips along the edges support pitch and yaw. Corner areas support roll. The following figure illustrates these regions.

Viewing Annotations Annotations provide the following visual information: • Boundary of the scope region by coloring the geometry for edges, faces or vertices. 114

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Working with Graphics • An explicit vertex within the scope. • A 3D arrow to indicate direction, if applicable. • Text description or a value. • A color cue (structural vs. thermal, etc.).

Note The custom annotations you add using Label remain visible even when you suppress the body. This section addresses the following types of annotations: Highlight and Selection Graphics (p. 115) Scope Graphics (p. 115) Annotation Graphics and Positioning (p. 116) Annotations of Multiple Objects (p. 117) Rescaling Annotations (p. 117) Solution Annotations (p. 118) In addition, you can also specify preferences for your annotations. For more information, see Specifying Annotation Preferences (p. 119).

Highlight and Selection Graphics You can interactively highlight a face. The geometry highlights when you point to it.

See Selecting Geometry (p. 87) for details on highlighting and selection.

Scope Graphics In general, selecting an object in the Tree Outline (p. 3) displays its Scope by painting the geometry and displays text annotations and symbols as appropriate. The display of scope via annotation is carried over into the Report Preview (p. 22) if you generate a figure. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Application Interface Contours are painted for results on the scoped geometry. No boundary is drawn.

Annotation Graphics and Positioning A label consists of a block arrow cross-referenced to a color-coded legend. For vector annotations, a 3D arrow originates from the tip of the label to visualize direction relative to the geometry.

Use the pointer after selecting the Label toolbar button the annotation to a different location within the scope.

for managing annotations and to drag

• If other geometry hides the 3D point (e.g. the point lies on a back face) the block arrow is unfilled (transparent).

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Working with Graphics • The initial placement of an annotation is at the pick point. You can then move it by using the Label toolbar button for managing annotations. • Drag the label to adjust the placement of an annotation. During the drag operation the annotation moves only if the tip lies within the scope. If the pointer moves outside the scope, the annotation stops at the boundary.

Annotations of Multiple Objects When multiple individual objects or a folder (such as environment, contact, or named selections) are selected in the Tree Outline (p. 3), an annotation for each one appears on the geometry. The default number of annotations shown is 10, but you can change it to any value from 0 to 50 in the Graphics options. For more information, see Graphics (p. 80). Note that, if you have a large number of objects, you may want to display each object as a different color. For more information, see the Random Colors toolbar button documentation.

Rescaling Annotations This feature modifies the size of annotation symbols, such as load direction arrows, displayed in the Mechanical application. For example, and as illustrated below, you can reduce the size of the pressure direction arrow when zooming in on a geometry selection. To change the size of an annotation, click the Rescale Annotation toolbar button (

).

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Solution Annotations Solution annotations work similar to Annotations of Multiple Objects (p. 117). The Max annotation has red background. The Min annotation has blue background. Probe annotations have cyan backgrounds.

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Working with Graphics

• By default, annotations for Max and Min appear automatically for results but may be controlled by buttons in the Result Context Toolbar (p. 59). in the Result Context Toolbar (p. 59). Probe an• You may create «probe» annotations by clicking notations show the value of the result at the location beneath the tip, when initially constructed. When probe annotations are created, they do not trigger the database to be marked as save being needed (i.e. you will not be prompted to save). Be sure to issue a save if you wish to retain these newly created probe annotations in the database. Changes to the unit system deletes active probe annotations. In addition, probe annotations are not displayed if a Mechanical application database is opened in a unit system other than the one in which it was saved; however, the probe annotations are still available and display when the Mechanical application database is opened in the original unit system. • If you apply a probe annotation to a very small thickness, such as when you scope results to an edge, the probe display may seem erratic or non-operational. This is because, for ease of viewing, the colored edge result display is artificially rendered to appear larger than the actual thickness. You can still add a probe annotation in this situation by zooming in on the thin region before applying the probe annotation. • To delete a probe annotation, activate the Label button key.

, select the probe, and then press the Delete

• Probes will be cleared if the results are re-solved. • After adding one or more probe annotations, if you increase the number of viewports, the probe annotations only appear in one of the viewports. If you then decrease the number of viewports, you must first highlight the header in the viewport containing the probe annotations in order to preserve the annotations in the resulting viewports. • See the Solution Context Toolbar (p. 59) for more information.

Specifying Annotation Preferences The Annotation Preferences dialog box controls the visibility of all annotations, including custom annotations and annotation labels, annotations on objects such as cracks, point masses, and springs, and the coordinate system display. To set your annotation preferences: 1.

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Application Interface The Annotation Preferences dialog box appears. By default, all annotations are selected, and thus set to visible. 2.

Under Basic Annotations, select or clear the check boxes for the following options: • Annotations: Toggles the visibility of annotations in the graphics window. • User Defined Graphics Annotations: Toggles the visibility of custom user annotation in the graphics window. • Annotation Labels: Toggles the visibility of annotation labels in the graphics window.

3.

Under Remote Boundary Conditions, select or clear the check boxes for the following options: • Point Masses: Toggles the visibility of annotations for point masses. • Springs: Toggles the visibility of annotations for springs. • Beam Connections: Toggles the visibility of annotations for beam connections. • Bearings: Toggles the visibility of annotations for bearings.

Note The size range for Point Masses and Springs is from 0.2-2 (Small-0.2, Default-1, Large-2).

4.

Under Remote Boundary Conditions, slide the indicator to specify the size of the annotations for Point Masses and Springs.

5.

Under Additional Display Preferences, select or clear the check boxes for the following options: • Crack Annotations: Toggles the visibility of annotations on crack objects. • Individual Force Arrows on Surface Reactions: Toggles the visibility of individual force arrows on surface reactions. • Body Scoping Annotations: Toggles the visibility of annotations on body scoping.

6.

Under Mesh Display, select or clear the check boxes for the following options: • Mesh Annotations: Toggles the visibility of mesh node and mesh element annotations in Named Selection displays. • Node Numbers: Toggles the visibility of mesh node numbers in Named Selection, Mesh, and Result displays. • Plot Elements Attached to Named Selections: Toggles the visibility of elements for all items in the Named Selections group. For nodal Named Selections, this option shows the full elements, while for face or body Named Selections this option shows just the element faces. This option does not affect Line Bodies. You must have the Show Mesh button toggled off to see the elements in the Named Selection.

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Working with Graphics 7.

When you are finished specifying your annotation preferences, click Apply Changes to apply your preferences and leave the dialog box open, or click OK to apply and close.

Controlling Lighting The Details view properties of the Model object provide lighting controls that affect the display in the Graphics Window.

Inserting Comments, Images, and Figures You can insert Comment objects, Image objects, or Figure objects under various parent objects in the Mechanical tree to add text or graphical information that pertain specifically to those parent objects. Refer to their individual objects reference pages for descriptions. Additional information on Figure objects is presented below. Figures allow you to: • Preserve different ways of viewing an object (viewpoints and settings). • Define illustrations and captions for a report. • Capture result contours, mesh previews, environment annotations etc., for later display in Report. Clicking the Figure button in the Standard Toolbar (p. 49) creates a new Figure object inside the selected object in the Tree Outline (p. 3). Any object that displays 3D graphics may contain figures. The new figure object copies all current view settings and gets focus in the Outline automatically. View settings maintained by a figure include: • Camera settings • Result toolbar settings • Legend configuration A figure’s view settings are fully independent from the global view settings. Global view settings are maintained independently of figures. Behaviors: • If you select a figure after selecting its parent in the Outline, the graphics window transforms to the figure’s stored view settings automatically (e.g. the graphics may automatically pan/zoom/rotate). • If you change the view while a figure is selected in the Outline, the figure’s view settings are updated. • If you reselect the figure’s parent in the Outline, the graphics window resumes the global view settings. That is, figure view settings override but do not change global view settings. • Figures always display the data of their parent object. For example, following a geometry Update and Solve, a result and its figures display different information but reuse the existing view and graphics options. Figures may be moved or copied among objects in the Outline to display different information from the same view with the same settings. • You may delete a figure without affecting its parent object. Deleting a parent object deletes all figures (and other children). Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Application Interface • In the Tree Outline (p. 3), the name of a figure defaults to simply Figure appended by a number as needed. • You may enter a caption for a figure as a string in the figure’s details. It is your responsibility to maintain custom captions when copying figures.

Mechanical Hotkeys To quickly perform certain actions in Mechanical, use the following hotkeys and hotkey combinations.

Tree Outline Actions F1: opens the Mechanical User’s Guide. F2: rename a selected tree object. Ctrl + S: save the project.

Graphics Actions F6: toggles between the Shaded Exterior and Edges, Shaded Exterior, and Wireframe views (also available on the View Menu). F7: executes Zoom to Fit option (also available on the Graphics Toolbar). F8: hide selected faces. F9: hide selected bodies. Ctrl + A: selects all entities based on the active selection filter (bodies, faces, edges, vertices, nodes).

Selection Filters These selection filters are also available on the Graphics Toolbar. Ctrl Ctrl Ctrl Ctrl

+ + + +

B: activate Body selection. E: activate Edge selection. F: activate Face selection. P: activate Vertex selection.

Wizards Wizards provide a layer of assistance above the standard user interface. They are made up of tasks or steps that help you interpret and work with simulations. Conceptually, the wizards act as an agent between you and the standard user interface. Wizards include the following features: • An interactive checklist for accomplishing a specific goal • A reality check of the current simulation • A list of a variety of high-level tasks, and guidance in performing the tasks • Links to useful resources

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Wizards • A series of Callout windows which provide guidance for each step

Note Callouts close automatically, or you may click inside a Callout to close it. Wizards use hyperlinks (versus command buttons) because they generally represent links to locations within the standard user interface, to content in the help system, or to a location accessible by a standard HTML hyperlink. The status of each step is taken in context of the currently selected Tree Outline (p. 3) object. Status is continually refreshed based on the Outline state (not on an internal wizard state). As a result you may: • Freely move about the Tree Outline (p. 3) (including between branches). • Make arbitrary edits without going through the wizards. • Show or hide the wizards at any time. Wizards are docked to the right side of the standard user interface for two reasons: • The Tree Outline (p. 3) sets the context for status determination. That is, the wizards interpret the Outline rather than control it. (The user interface uses a top-down left-right convention for expressing dependencies.) • Visual symmetry is maintained. To close wizards, click the . To show/hide tasks or steps, click the section header. Options for wizards are set in the Wizard (p. 85) section of the Options dialog box under the Mechanical application. The The Mechanical Wizard (p. 123) is available for your use in the Mechanical application.

The Mechanical Wizard The Mechanical Wizard appears in the right side panel whenever you click the in the toolbar. You at the top of the panel. To show or hide the can close the Mechanical Wizard at any time by clicking sections of steps in the wizard, click the section header.

Features of the Mechanical Wizard The Mechanical Wizard works like a web page consisting of collapsible groups and tasks. Click a group title to expand or collapse the group; click a task to activate the task. When activated, a task navigates to a particular location in the user interface and displays a callout with a message about the status of the task and information on how to proceed. Activating a task may change your tab selection, cursor mode, and Tree Outline (p. 3) selection as needed to set the proper context for proceeding with the task. You may freely click tasks to explore the Mechanical application. Standard tasks WILL NOT change any information in your simulation. Callouts close automatically based on your actions in the software. Click inside a callout to close it manually.

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Application Interface Most tasks indicate a status via the icon to the left of the task name. Rest your mouse on a task for a description of the status. Each task updates its status and behavior based on the current Tree Outline (p. 3) selection and software status. Tasks are optional. If you already know how to perform an operation, you don’t need to activate the task. Click the Choose Wizard task at the top of the Mechanical Wizard to change the wizard goal. For example, you may change the goal from Find safety factors to Find fatigue life. Changing the wizard goal does not modify your simulation. At your discretion, simulations may include any available feature not covered under Required Steps for a wizard. The Mechanical Wizard does not restrict your use of the Mechanical application. You may use the Mechanical Wizard with databases from previous versions of the Mechanical application. To enable the Mechanical Wizard, click

or select View> Windows> the Mechanical Wizard.

Types of the Mechanical Wizards There are wizards that guide you through the following simulations: • Safety factors, stresses and deformation • Fatigue life and safety factor • Natural frequencies and mode shapes • Optimizing the shape of a part • Heat transfer and temperatures • Magnetostatic results • Contact region type and formulation

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Steps for Using the Mechanical Application This section describes the overall workflow involved when performing any analysis in the Mechanical application. The following workflow steps are described: Create Analysis System Define Engineering Data Attach Geometry Define Part Behavior Define Connections Apply Mesh Controls and Preview Mesh Establish Analysis Settings Define Initial Conditions Applying Pre-Stress Effects for Implicit Analysis Applying Pre-Stress Effects for Explicit Analysis Apply Loads and Supports Solve Review Results Create Report (optional)

Create Analysis System There are several types of analyses you can perform in the Mechanical application. For example, if natural frequencies and mode shapes are to be calculated, you would choose a modal analysis. Each analysis type is represented by an analysis system that includes the individual components of the analysis such as the associated geometry and model properties. Most analyses are represented by one independent analysis system. However, an analysis with data transfer can exist where results of one analysis are used as the basis for another analysis. In this case, an analysis system is defined for each analysis type, where components of each system can share data. An example of an analysis with data transfer is a response spectrum analysis, where a modal analysis is a prerequisite. • To create an analysis system, expand the Standard Analyses folder in the Toolbox and drag an analysis type object “template” onto the Project Schematic. The analysis system is displayed as a vertical array of cells (schematic) where each cell represents a component of the analysis system. Address each cell by right-clicking on the cell and choosing an editing option. • To create an analysis system with data transfer to be added to an existing system, drag the object template representing the upstream analysis directly onto the existing system schematic such that red boxes enclose cells that will share data between the systems. After you up-click, the two schematics are displayed, including an interconnecting link and a numerical designation as to which cells share data. See Working through a System for more information.

Unit System Behavior When you start the Mechanical application, the unit system defaults to the same system used in the previous session. You can change this unit system, but subsequent Mechanical editors that you start Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Steps for Using the Application while the first one is open, will default to the unit system from the initial session. In the event that you change a unit system, numerical values are converted accordingly but there is no change in physical quantity.

Define Engineering Data A part’s response is determined by the material properties assigned to the part. • Depending on the application, material properties can be linear or nonlinear, as well as temperature-dependent. • Linear material properties can be constant or temperature-dependent, and isotropic or orthotropic. • Nonlinear material properties are usually tabular data, such as plasticity data (stress-strain curves for different hardening laws), hyperelastic material data. • To define temperature-dependent material properties, you must input data to define a property-versustemperature graph. • Although you can define material properties separately for each analysis, you have the option of adding your materials to a material library by using the Engineering Data tab. This enables quick access to and re-use of material data in multiple analyses. • For all orthotropic material properties, by default, the Global Coordinate System is used when you apply properties to a part in the Mechanical application. If desired, you can also apply a local coordinate system to the part. To manage materials, right-click on the Engineering Data cell in the analysis system schematic and choose Edit. See «Basics of Engineering Data» for more information.

Attach Geometry There are no geometry creation tools in the Mechanical application. You create your geometry in an external application or import an existing mesh file. Options to bring geometry into Mechanical; include: • From within Workbench using DesignModeler. See the DesignModeler Help for details on the use of the various creation tools available. • From a CAD system supported by Workbench or one that can export a file that is supported by ANSYS Workbench. See the CAD Systems section for a complete list of the supported systems. • From within Workbench using the External Model component system. This feature imports an ANSYS Mesh (.cdb) file. See the Mesh-Based Geometry section in the Specifying Geometry in the Mechanical Application Help. Before attaching geometry, you can specify several options that determine the characteristics of the geometry you choose to import. These options are: solid bodies, surface bodies, line bodies, parameters, attributes, named selections, material properties; Analysis Type (2D or 3D), allowing CAD associativity, importing coordinate systems (Import Work Points are only available in the DesignModeler application), saving updated CAD file in reader mode, “smart” refreshing of models with unmodified components, and allowing parts of mixed dimension to be imported as assembly components that have parts of

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Attach Geometry different dimensions. The availability of these options varies across the supported CAD systems. See the Geometry Preferences section for details.

Related Procedures Procedure Specifying geometry options

Condition Optional task that can be done before attaching geometry.

Procedural Steps 1. In an analysis system schematic, perform either of the following: • Right-click on the Geometry cell and choose Properties OR • Select the Geometry cell in the schematic for a standard analysis, then from the View drop-down menu, choose any option that includes Properties or Components. 2. Check boxes to specify Default Geometry Options and Advanced Geometry Defaults.

Attaching DesignModeler geometry to the Mechanical application

DesignModeler is running in an analysis system.

Double-click on the Model cell in the same analysis system schematic. The Mechanical application opens and displays the geometry.

DesignModeler is not running. Geometry is stored in an agdb file.

1. Select the Geometry cell in an analysis system schematic. 2. Browse to the agdb file from the following access points: • Right-click on the Geometry cell in the Project Schematic, Import Geometry and choose Browse. 3. Double-click on the Model cell in the schematic. The Mechanical application opens and displays the geometry.

Attaching CAD geometry to the Mechanical application

CAD system is running.

1. Select the Geometry cell in an analysis system schematic. 2. Right-click on the Geometry cell listed to select geometry for import. 3. If required, set geometry options for import into the Mechanical application by highlighting the Geometry cell and choosing settings under Preferences in the Properties Panel. 4. Double-click on the Model cell in the same analysis system schematic. The Mechanical application opens and displays the geometry.

CAD system is not running. Geometry is stored

1. Select the Geometry cell in an analysis system schematic. 2. Browse to the CAD file from the following access points:

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Steps for Using the Application Procedure

Condition in a native CAD system file, or in a CAD “neutral” file such as Parasolid or IGES.

Procedural Steps • Right-click on the Geometry cell in the Project Schematic and choose Import Geometry. 3. Double-click on the Model cell in the Project Schematic. The Mechanical application opens and displays the geometry.

CAD Interface Terminology The CAD interfaces can be run in either plug-in mode or in reader mode. • Attaching geometry in plug-in mode: requires that the CAD system be running. • Attaching geometry in reader mode: does not require that the CAD system be running.

Updating Geometry from Within the Mechanical Application You can update all geometry by selecting the Update Geometry from Source context menu option, accessible by right-clicking on the Geometry tree object or anywhere in the Geometry window. The following update options are also available: • Selective Update (p. 128) • Smart CAD Update (p. 129) Selective Update Using the Geometry object right-click menu option Update Selected Parts>Update: Use Geometry Parameter Values, you can selectively update individual parts and synchronize the Mechanical application model to the CAD model. This option reads the latest geometry and processes any other data (parameters, attributes, etc.) based on the current user preferences for that model.

Note Changes to either the number of turns or the thickness properties associated with a body do not update the CAD model. This update feature only applies parts that you select. It does not import new parts added in the CAD system following the original import or last complete update. Assembly Parameter values are always updated. In addition, this feature is not a tool for removing parts from the Mechanical application tree, however; it will remove parts which have been selected for update in WB, but that no longer exist in the CAD model if an update is successful (if at least one valid part is updated). The Update Selected Parts feature supports the associative geometry interfaces for: • DesignModeler • Autodesk Inventor

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Define Part Behavior • CATIA V5 • Creo Elements/Direct Modeling • Creo Parametric (formerly Pro/ENGINEER) • Solid Edge • NX • SolidWorks With the exception of AutoCAD, executing the selective update feature on any unsupported interface will complete a full update of the model. Smart CAD Update Using the Geometry Preferences, you enable the Smart CAD Update. Note that Geometry Preferences are supported by a limited number of CAD packages. See the Project Schematic Advanced Geometry Options table for details.

Define Part Behavior After attaching geometry, you can access settings related to part behavior by right-clicking on the Model cell in the analysis system schematic and choosing Edit …. The Mechanical application opens with the environment representing the analysis system displayed under the Model object in the tree. An Analysis Settings object is added to the tree. See the Establish Analysis Settings (p. 134) overall step for details. An Initial Condition object may also be added. See the Define Initial Conditions (p. 136) overall step for details. The Mechanical application uses the specific analysis system as a basis for filtering or making available only components such as loads, supports and results that are compatible with the analysis. For example, a Static Structural analysis type will allow only structural loads and results to be available. Presented below are various options provided in the Details view for parts and bodies following import.

Stiffness Behavior In addition to making changes to the material properties of a part, you may designate a part’s Stiffness Behavior as being flexible, rigid, or as a gasket. • Setting a part’s behavior as rigid essentially reduces the representation of the part to a single point mass thus significantly reducing the solution time. • A rigid part will need only data about the density of the material to calculate mass characteristics. Note that if density is temperature dependent, density will be evaluated at the reference temperature. For contact conditions, specify Young’s modulus. • Flexible and rigid behaviors are applicable only to static structural, transient structural, rigid dynamics, explicit dynamics, and modal analyses. Gasket behavior is applicable only to static structural analyses.

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Steps for Using the Application Flexible is the default Stiffness Behavior. To change, simply select Rigid or Gasket from the Stiffness Behavior drop-down menu. Also see the Rigid Bodies (p. 401) section or the Gasket Bodies section.

Note Rigid behavior is not available for the Samcef solver.

Coordinate Systems The Coordinate Systems object and its child object, Global Coordinate System, is automatically placed in the tree with a default location of 0, 0, 0, when a model is imported. For solid parts and bodies: by default, a part and any associated bodies use the Global Coordinate System. If desired, you can apply a apply a local coordinate system to the part or body. When a local coordinate system is assigned to a Part, by default, the bodies also assume this coordinate system but you may modify the system on the bodies individually as desired. For surface bodies, solid shell bodies, and line bodies: by default, these types of geometries generate coordinates systems on a per element type basis. It is necessary for you to create a local coordinate system and associated it with the parts and/or bodies using the Coordinate System setting in the Details view for the part/body if you wish to orient those elements in a specific direction.

Reference Temperature The default reference temperature is taken from the environment (By Environment), which occurs when solving. This necessarily means that the reference temperature can change for different solutions. The reference temperature can also be specified for a body and will be constant for each solution (By Body). Selecting By Body will cause the Reference Temperature Value field to specify the reference temperature for the body. It is important to recognize that any value set By Body will only set the reference temperature of the body and not actually cause the body to exist at that temperature (unlike the Environment Temperature entry on an environment object, which does set the body’s temperature).

Note Selecting By Environment can cause the body to exist at that temperature during the analysis but selecting By Body will only ever effect reference temperature. So if the environment temperature and the body have a different specification, thermal expansion effects can occur even if no other thermal loads are applied.

Note If the material density is temperature dependent, the mass that is displayed in the Details view will either be computed at the body temperature, or at 22°C. Therefore, the mass

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Define Part Behavior computed during solution can be different from the value shown, if the Reference Temperature is the Environment.

Note When nonlinear material effects are turned off, values for thermal conductivity, specific heat, and thermal expansion are retrieved at the reference temperature of the body when creating the ANSYS solver input.

Reference Frame The Reference Frame determines the analysis treatment perspective of the body for an Explicit Dynamics analysis. The Reference Frame property is available for solid bodies when an Explicit Dynamics system is part of the solution. The valid values are Langrangian (default) and Eulerian (Virtual). Eulerian is not a valid selection if Stiffness Behavior is set to Rigid.

Material Assignment Once you have attached your geometry, you can choose a material for the simulation. When you select a part in the tree outline, the Assignment entry under Material in the Details view lists a default material for the part. From the fly-out menu, you can: • Create a new material definition • Import a material • Edit the characteristics of the current material • Assign a material from the list of available materials.

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Steps for Using the Application When you edit the currently assigned material, create a material, or import a material, you work in the Engineering Data tab. Once you have completed any of those operations, you must refresh the model cell in the Project Schematic to bring new data into the Mechanical application.

Nonlinear Material Effects You can also choose to ignore any nonlinear effects from the material properties. • By default the program will use all applicable material properties including nonlinear properties such as stress-strain curve data. • Setting Nonlinear Effects to No will ignore any nonlinear properties only for that part. • This option will allow you to assign the same material to two different parts but treat one of the parts as linear. • This option is applicable only for static structural, transient structural, steady state thermal and transient thermal analyses.

Thermal Strain Effects For structural analyses, you can choose to have Workbench calculate a Thermal Strain result by setting Thermal Strain Effects to Yes. Choosing this option enables the coefficient of thermal expansion to be sent to the solver.

Cross Section When a line body is imported into the Mechanical application, the Details view displays the Cross Section field and associated cross section data. These read-only fields display the name and data assigned to the geometry in DesignModeler or the supported CAD system, if one was defined. See Line Bodies (p. 387) for further information.

Model Dimensions When you attach your geometry or model, the model dimensions display in the Details View (p. 11) in the Bounding Box sections of the Geometry or Part objects. Dimensions have the following characteristics: • Units are created in your CAD system. • ACIS and CATIA model units may be set. • Other geometry units are automatically detected and set. • Assemblies must have all parts dimensioned in the same units.

Define Connections Once you have addressed the material properties and part behavior of your model, you may need to apply connections to the bodies in the model so that they are connected as a unit in sustaining the applied loads for analysis. Available connection features are: • Contacts: defines where two bodies are in contact or a user manually defines contact between two bodies.

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Apply Mesh Controls and Preview Mesh • Joints: a contact condition in the application that is defined by a junction where bodies are joined together that has rotational and translational degrees of freedom. • Mesh Connections: used to join the meshes of topologically disconnected surface bodies that reside in different parts. • Springs: defines as an elastic element that connects two bodies or a body to “ground” that maintains its original shape once the specified forces are removed. • Bearings: are used to confine relative motion and rotation of a rotating machinery part. • Beam Connections: used to establish body to body or body to ground connections. • End Releases are used to release degrees of freedoms at a vertex shared by two or more edges of one or more line bodies. • Spot Welds: connects individual surface body parts together to form surface body model assemblies. Given the complex nature of bodies coming into contact with one another, especially if the bodies are in motion, it is recommended that you review the Connections section of the documentation.

Apply Mesh Controls and Preview Mesh Meshing is the process in which your geometry is spatially discretized into elements and nodes. This mesh along with material properties is used to mathematically represent the stiffness and mass distribution of your structure. Your model is automatically meshed at solve time. The default element size is determined based on a number of factors including the overall model size, the proximity of other topologies, body curvature, and the complexity of the feature. If necessary, the fineness of the mesh is adjusted up to four times (eight times for an assembly) to achieve a successful mesh. If desired, you can preview the mesh before solving. Mesh controls are available to assist you in fine tuning the mesh to your analysis. Refer to the Meshing Help for further details.

To preview the mesh in the Mechanical Application: See the Previewing Surface Mesh section.

To apply global mesh settings in the Mechanical Application: See the Global Mesh Controls section.

To apply mesh control tools on specific geometry in the Mechanical Application: See the Local Mesh Controls section.

To use virtual topology: All virtual topology operations in the Mechanical application are described in the Virtual Topology section of the Meshing Help.

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Steps for Using the Application

Establish Analysis Settings Each analysis type includes a group of analysis settings that allow you to define various solution options customized to the specific analysis type, such as large deflection for a stress analysis. Refer to the specific analysis types section for the customized options presented under “Preparing the Analysis”. Default values are included for all settings. You can accept these default values or change them as applicable. Some procedures below include animated presentations. Please view online if you are reading the PDF version of the help. Interface names and other components shown in the demos may differ from those in the released product. To verify/change analysis settings in the Mechanical application: 1.

Highlight the Analysis Settings object in the tree. This object was inserted automatically when you established a new analysis in the Create Analysis System (p. 125) overall step.

2.

Verify or change settings in the Details view of the Analysis Settings object. These settings include default values that are specific to the analysis type. You can accept or change these defaults. If your analysis involves the use of steps, refer to the procedures presented below.

To create multiple steps (applies to structural static, transient structural, rigid dynamics, steady-state thermal, transient thermal, magnetostatic, and electric analyses): You can create multiple steps using any one of the following methods: 1.

Highlight the Analysis Settings object in the tree. Modify the Number of Steps field in the Details view. Each additional Step has a default Step End Time that is one second more than the previous step. These step end times can be modified as needed in the Details view. You can also add more steps simply by adding additional step End Time values in the Tabular Data window. The following demonstration illustrates adding steps by modifying the Number of Steps field in the Details view.

Or 2.

Highlight the Analysis Settings object in the tree. Begin adding each step’s end time values for the various steps to the Tabular Data window. You can enter the data in any order but the step end time points will be sorted into ascending order. The time span between the consecutive step end times will form a step. You can also select a row(s) corresponding to a step end time, click the right mouse button and choose Delete Rows from the context menu to delete the corresponding steps. The following demonstration illustrates adding steps directly in the Tabular Data window.

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Establish Analysis Settings Or 3.

Highlight the Analysis Settings object in the tree. Choose a time point in the Graph window. This will make the corresponding step active. Click the right mouse button and choose Insert Step from the context menu to split the existing step into two steps, or choose Delete Step to delete the step. The following demonstration illustrates inserting a step in the Graph window, changing the End Time in the Tabular Data window, deleting a step in the Graph window, and deleting a step in the Tabular Data window.

Specifying Analysis Settings for Multiple Steps 1.

Create multiple steps following the procedure ”To create multiple steps” above.

2.

Most Step Controls, Nonlinear Controls, and Output Controls fields in the Details view of Analysis Settings are “step aware”, that is, these settings can be different for each step. Refer to the table in Analysis Settings for Most Analysis Types (p. 635) to determine which specific controls are step aware (designated as footnote 2 in the table). Activate a particular step by selecting a time value in the Graph window or the Step bar displayed below the chart in the Graph window. The Step Controls grouping in the Details view indicates the active Step ID and corresponding Step End Time. The following demonstration illustrates turning on the legend in the Graph window, entering analysis settings for a step, and entering different analysis settings for another step.

If you want to specify the same analysis setting(s) to several steps, you can select all the steps of interest as follows and change the analysis settings details. • To change analysis settings for a subset of all of the steps: – From the Tabular Data window: 1. Highlight the Analysis Settings object. 2. Highlight steps in the Tabular Data window using either of the following standard windowing techniques: → Ctrl key to highlight individual steps. → Shift key to highlight a continuous group of steps. 3. Click the right mouse button in the window and choose Select All Highlighted Steps from the context menu.

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Steps for Using the Application 4. Specify the analysis settings as needed. These settings will apply to all selected steps. – From the Graph window: 1. Highlight the Analysis Settings object. 2. Highlight steps in the Graph window using either of the following standard windowing techniques: → Ctrl key to highlight individual steps. → Shift key to highlight a continuous group of steps. 3. Specify the analysis settings as needed. These settings will apply to all selected steps. • To specify analysis settings for all the steps: 1. Click the right mouse button in either window and choose Select All Steps. 2. Specify the analysis settings as needed. These settings will apply to all selected steps. The following demonstration illustrates multiple step selection using the bar in the Graph window, entering analysis settings for all selected steps, selecting only highlighted steps in the Tabular Data window, and selecting all steps.

The Worksheet for the Analysis Settings object provides a single display of pertinent settings in the Details view for all steps.

Details of various analysis settings are discussed in «Configuring Analysis Settings» (p. 635).

Define Initial Conditions This step is based upon the selected type analysis. Workbench provides you with the ability to begin your analysis with an initial condition, a link to an existing solved or associated environment, or an initial temperature. For the following analysis types, a tree object is automatically generated allowing you to define specifications. For additional information, see the individual analysis types section. 136

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Define Initial Conditions Analysis Type

Tree Object

Description

Transient Structural

Initial Condi- By default, a transient structural analysis is at rest. However, you can tions folder define velocity as an initial condition by inserting a Velocity object under the Initial Conditions folder.

Explicit Dynamics

Initial Conditions folder: Pre-Stress object

Because an explicit dynamics analysis is better suited for short duration events, preceding it with an implicit analysis may produce a more efficient simulation especially for cases in which a generally slower (or rate-independent) phenomenon is followed by a much faster event, such as the collision of a pressurized container. For an Explicit Dynamics system, the Initial Conditions folder includes a Pre-Stress object to control the transfer of data from an implicit static or transient structural analysis to the explicit dynamics analysis. Transferable data include the displacements, or the more complete Material State (displacements, velocities, stresses, strains, and temperature). See Recommended Guidelines for Pre-Stress Explicit Dynamics (p. 141) for more information. An explicit dynamics analysis is at rest by default. However, for both Explicit Dynamics and Explicit Dynamics (LS-DYNA Export) systems, you can define velocity or angular velocity as initial conditions by inserting a Velocity object or Angular Velocity object under the Initial Conditions folder.

Modal

Pre-Stress object

A Modal analysis can use the stress results from a static structural analysis to account for stress-stiffening effect. See the Modal Analysis (p. 196) section for details.

Linear Buckling

Pre-Stress object

A Linear Buckling analysis must use the stress-stiffening effects of a static structural analysis. See the Linear Buckling Analysis (p. 192) section for details.

Harmonic Response (Full)

Pre-Stress object

A Harmonic Response (Full) analysis linked to a Static Structural analysis can use the stress results to account for stress-stiffening effect.

Random Vibration, Response Spectrum, Harmonic Response MSUP (Mode Superposition) linked, or Transient (MSUP) linked

Initial Condi- A Random Vibration, Response Spectrum, Harmonic (Mode Superposition tions folder: — MSUP) linked or a Transient (MSUP) linked analysis must use the mode Modal object shapes derived in a Modal analysis.

Steady-State Thermal

Initial Temperature object

For a Steady-State Thermal analysis, you have the ability to specify an initial temperature.

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Steps for Using the Application Analysis Type

Tree Object

Description

Transient Thermal

Initial Temperature object

For a Transient Thermal analysis, the initial temperature distribution should be specified.

Note Temperatures from a steady-state thermal or transient thermal analysis can be applied to a static structural or transient structural analysis as a Thermal Condition load. Depending upon the analysis type an object is automatically added to the tree. To define an initial condition in the Mechanical application: • For a Transient Structural analysis, use the Initial Conditions object to insert Velocity. For an Explicit Dynamics analysis, use the Initial Conditions object to insert Velocity, Angular Velocity. These values can be scoped to specific parts of the geometry. • For a Harmonic Response, Modal, Linear Buckling, or Explicit Dynamics analysis, use the Details view of the Pre-Stress object to define the associated Pre-Stress Environment. For an Explicit Dynamics analysis, use the Details view of this object to select either Material State (displacements, velocities, strains and stresses) or Displacements only modes, as well as the analysis time from the implicit analysis which to obtain the initial condition. For Displacements only, a Time Step Factor may be specified to convert nodal DOF displacements in the implicit solution into constant velocities for the explicit analysis according to the following expression: Velocity = Implicit displacement/(Initial explicit time step x time step factor)

Note The Displacements only mode is applicable only to results from a linear, static structural analysis.

• For a Random Vibration or Response Spectrum analysis, you must point to a modal analysis using the drop-down list of the Modal Environment field in the Details view. • For the Steady-State and Transient Thermal analyses, use the Details of the Initial Temperature object to scope the initial temperature value. For a Transient Thermal analysis that has a non-uniform temperature, you need to define an associated Initial Temperature Environment. • The Details view of the Modal (Initial Conditions) object for linked Mode Superposition Harmonic and Mode Superposition Transient analyses displays the name of the pre-stress analysis system in the PreStress Environment field, otherwise the field indicates None.

Applying Pre-Stress Effects for Implicit Analysis Mechanical leverages the power of linear perturbation technology for all pre-stress analyses performed within Mechanical. This includes pre-stress Modal analyses, Full Harmonic Response analysis using a Pre-Stressed Structural System analyses, as well as Linear Buckling analyses. The following features are available that are based on this technology: 138

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Applying Pre-Stress Effects for Implicit Analysis • Large deflection static analysis followed by pre-stress modal analysis. Thus the static analysis can be linear or nonlinear including large deflection effects.

Note – If performing a pre-stress modal analysis, it is recommended that you always include large deflection effects to produce accurate results in the modal analysis. – Pre-stress results should always originate from the same version of the application as that of the modal solution. – Although the modal results (including displacements, stresses, and strains) will be correctly calculated in the modal analysis, the deformed shape picture inside Mechanical will be based on the initial geometry, not the deformed geometry from the static analysis. If you desire to see the mode shapes based on the deformed geometry, you can take the result file into Mechanical APDL.

• True contact status as calculated at the time in the static analysis from which the eigen analysis is based. • Support for cyclic analysis. • Support for multiple result sets in the static analysis. For a pre-stressed eigen analysis, you can insert a Commands object beneath the Pre-Stress initial conditions object. The commands in this object will be executed just before the first solve for the prestressed modal analysis.

Pressure Load Stiffness If the static analysis has a pressure load applied “normal to” faces (3D) or edges (2-D), this could result in an additional stiffness contribution called the “pressure load stiffness” effect. This effect plays a significant role in linear buckling analyses. Different buckling loads may be predicted from seemingly equivalent pressure and force loads in a buckling analysis because in the Mechanical application a force and a pressure are not treated the same. As with any numerical analysis, we recommend that you use the type of loading which best models the in-service component. For more information, see the Mechanical APDL Theory Reference, under Structures with Geometric Nonlinearities> Stress Stiffening> Pressure Load Stiffness.

Restarts from Multiple Result Sets A property called Pre-Stress Define By is available in the Details view of the Pre-Stress object in the eigen analysis. It is set to Program Controlled by default which means that it uses the last solve point available in the parent static structural analysis as the basis for the eigen analysis. There are three more read only properties defined in the Details view of the Pre-Stress object – Reported Loadstep, Reported Substep and Reported Time which are set to Last, Last, and End Time or None Available by default depending on whether or not there are any restart points available in the parent static structural analysis. These read only properties show the actual load step, sub step and time used as the basis for the eigen analysis. You can change Pre-Stress Define By to Load Step, and then another property called Pre-Stress Loadstep will appear in the Details view. Pre-Stress Loadstep gives you an option to start from any Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Steps for Using the Application load step in the static structural analysis. If you use this property, then Mechanical will always pick the last substep available in that load step. You can see the actual reported substep and time as read only properties. The input value of load step should be less than or equal to the number of load steps in the parent static structural analysis. Loadstep 0 stands for the last load step available. You can change Pre-Stress Define By to Time, and then another property called Pre-Stress Time will appear in the Details view. Pre-Stress Time gives you an option to start from any time in the static structural analysis. If there is no restart point available at the time of your input, then Mechanical will pick the closest restart point available in the static structural analysis. You can see the actual reported load step, sub step and time as read only properties. The input value of time should be non-negative and it should be less than the end time of parent static structural analysis. Time 0 stands for end time of the parent analysis. If there is no restart point available in the input loadstep and the number of restart points in the parent analysis is not equal to zero, then the following error message appears: “There is no restart point available at the requested loadstep. Please change the restart controls in the parent static structural analysis to use the requested loadstep.”

Note If you use Pre-Stress Time, then Mechanical will pick the closest restart point available. It may not be the last sub step of a load step; and if it is some intermediate substep in a load step, then the result may not be reproducible if you make any changes in the parent static structural analysis or you solve it again. If there is no restart point available in the parent static structural analysis, then Reported Loadstep, Reported Substep and Reported Time are set to None Available regardless of the user input of LoadStep/Time but these will be updated to correct values once the analysis is solved with the correct restart controls for the parent structural analysis.

Contact Status You may choose contact status for the pre-stressed eigen analysis to be true contact status, force sticking, or force bonded. A property called Contact Status is available in the Details view of the PreStress object in the eigen analysis. This property controls the CONTKEY field of the Mechanical APDL PERTURB command. • Use True Status (default): Uses the current contact status from the restart snapshot. If the previous run for parent static structural is nonlinear, then the nonlinear contact status at the point of restart is frozen and used throughout the linear perturbation analysis. • Force Sticking: Uses sticking contact stiffness for the frictional contact pairs, even when the status is sliding (that is, the no sliding status is allowed). This option only applies to contact pairs whose frictional coefficient is greater than zero. • Force Bonding: Uses bonded contact stiffness and status for contact pairs that are in the closed (sticking/sliding) state.

Applying Pre-Stress Effects for Explicit Analysis Because an explicit dynamics analysis is better suited for short duration events, preceding it with an implicit analysis may produce a more efficient simulation especially for cases in which a generally slower (or rate-independent) phenomenon is followed by a much faster event, such as the collision of a pressurized container. To produce this combination, you can define pre-stress as an initial condition in an 140

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Applying Pre-Stress Effects for Explicit Analysis Explicit Dynamics system, specifying the transfer of either displacements only or the more complete Material State (displacements, velocities, stresses, and strains), from a static or transient structural analysis to an explicit dynamics analysis. Characteristics of the implicit to explicit pre-stress feature: • Applicable to 3-D analyses only. • The Material State mode, for mapping stresses, plastic strains, displacements, and velocities is valid for solid models only. • The displacements only mode is valid for solid, shell, and beam models. • The same mesh is required for both implicit and explicit analyses and only low order elements are allowed. If high order elements are used, the solve will be blocked and an error message will be issued. • For a nonlinear implicit analysis, the Strain Details view property in the Output Controls category under the Analysis Settings object must be set to Yes because plastic strains are needed for the correct results.

Recommended Guidelines for Pre-Stress Explicit Dynamics The following guidelines are recommended when using pre-stress with an Explicit Dynamics analysis: • Lower order elements must be used in the static or transient structural analysis used to pre-stress the Explicit Dynamics analysis. To do so, set the Mesh object property, Element Midside Nodes (Advanced category), to Dropped. • On the Brick Integration Scheme of all relevant bodies, use the Reduced option, to provide the most consistent results between the Static Structural or Transient Structural system and the Explicit Dynamics system. Such a selection amounts to a single integration point per lower order solid element. • For models containing Line or Surface bodies, the data transfer is limited to displacements only. In this mode, under Analysis Settings, the Static Damping option (under Damping) should be used to remove any dynamic oscillations in the stress state due to the imposed static displacements. • The temperature state is also transferred to the Explicit Dynamics analysis. The Unit System is taken care of automatically, and Internal Energy due to difference in temperature will be added to each element based on: Einternal = Einternal + Cp(T-Tref) Where: Cp = specific heat coefficient Tref = room temperature Note that stresses may still dissipate because the thermal expansion coefficient is not taken into account in the Explicit Dynamics analysis. Example — Drop Test on Pressurized Container:

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Steps for Using the Application

Pre-stress condition:

Transient stress distribution during drop test:

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Apply Loads and Supports

Pre-Stress Object Properties Mode Displacement Node-based displacements from a static analysis are used to initialize the explicit node positions. These displacements are converted to constant node-based velocities and applied for a pre-defined time in order to obtain the required displaced coordinates. During this times, element stresses and strains are calculated as normal by the explicit solver. Once the displaced node positions are achieved, all node-based velocities are set to 0 and the solution is completely initialized. This option is applicable to unstructured solids (hexahedral and tetrahedral), shells, and beams. Time Step Factor The initial time step from the explicit solution is multiplied by the time step factor. The resulting time is used with the nodal displacements from the ANSYS Mechanical analysis to calculate constant nodal velocities. These nodal velocities are applied to the explicit model over the resulting time in order to initialize the explicit nodes to the correct positions. Material State Node-based displacements, element stresses and strains, and plastic strains and velocities from an implicit solution are used to initialize an explicit analysis at cycle 0. This option is applicable to results from a linear static structural, nonlinear static structural, or transient dynamic Mechanical system. The ANSYS solution may be preceded with a steady-state thermal solution in order to introduce temperature differences into the solution. In this case, the accompanying thermal stresses due to the thermal expansion coefficient will be transferred but may dissipate since the thermal expansion coefficient is not considered in an explicit analysis. This option is only applicable to unstructured solid elements (hexahedral and tetrahedral). Pressure Initialization From Deformed State The pressure for an element is calculated from its compression, which is determined by the initial displacement of the element’s nodes. This is the default option and should be used for almost all implicit-explicit analyses. From Stress State The pressure for an element is calculated from the direct stresses imported from the implicit solution. This option is only available for materials with a linear equation of state. If the pressure for an element is already initialized, this calculation will be ignored. This is for a prestress analysis from an implicit solution that has been initialized from an INISTATE command and has an .rst file with all degrees of freedom fixed. Time The time at which results are extracted from the implicit analysis.

Apply Loads and Supports You apply loads and support types based on the type of analysis. For example, a stress analysis may involve pressures and forces for loads, and displacements for supports, while a thermal analysis may involve convections and temperatures. Loads applied to static structural, transient structural, rigid dynamics, steady-state thermal, transient thermal, magnetostatic, electric, and thermal-electric analyses default to either step-applied or ramped. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Steps for Using the Application That is, the values applied at the first substep stay constant for the rest of the analysis or they increase gradually at each substep. Load

Load

Full value applied

Substep Load step

at first substep 1

1 Final load value

2

2

Time (a) Stepped loads

Time (b) Ramped loads

You can edit the table of load vs. time and modify this behavior as needed. By default you have one step. However you may introduce multiple steps at time points where you want to change the analysis settings such as the time step size or when you want to activate or deactivate a load. An example is to delete a specified displacement at a point along the time history. You do not need multiple steps simply to define a variation of load with respect to time. You can use tables or functions to define such variation within a single step. You need steps only if you want to guide the analysis settings or boundary conditions at specific time points. When you add loads or supports in a static or transient analysis, the Tabular Data and Graph windows appear. You can enter the load history, that is, Time vs Load tabular data in the tabular data grid. Another option is to apply loads as functions of time. In this case you will enter the equation of how the load varies with respect to time. The procedures for applying tabular or function loads are outlined under the Defining Boundary Condition Magnitude (p. 848) section.

Note • You can also import or export load histories from or to any pre-existing libraries. • If you have multiple steps in your analysis, the end times of each of these steps will always appear in the load history table. However you need not necessarily enter data for these time points. These time points are always displayed so that you can activate or deactivate the load over each of the steps. Similarly the value at time = 0 is also always displayed. • If you did not enter data at a time point then the value will be either a.) a linearly interpolated value if the load is a tabular load or b.) an exact value determined from the function that defines the load. An “=” sign is appended to such interpolated data so you can differentiate between the data that you entered and the data calculated by the program as shown in the example below. Here the user entered data at Time = 0 and Time = 5. The value at Time = 1e-3, the end time of step 1, is interpolated.

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Solve

To apply loads or supports in the Mechanical Application: See the «Setting Up Boundary Conditions» (p. 691) section.

Solve The Mechanical application uses the same solver kernels that ANSYS Mechanical APDL (MAPDL) uses. At the Solve step, Mechanical passes its data to the appropriate MAPDL solver kernel, based on the type of analysis to be performed. That kernel then passes the solution data back to Mechanical, where you are able to look at the results. Because the same solver kernels are used, you will obtain the same results from Mechanical that you would if doing the same analysis in MAPDL. Based on the analysis type, the following solvers are available in Mechanical: • Mechanical ANSYS Parametric Design Language (MAPDL) Solver. • ANSYS Rigid Dynamics Solver: only available for Rigid Dynamics Analysis. • LS-DYNA Solver: only available for Explicit Dynamics analysis. • Explicit Dynamics Solver (AUTODYN): only available for Explicit Dynamics analysis. • Samcef Solver: only available for Static Structural and Modal analyses. You can execute the solution process on your local machine or on a remote machine such as a powerful server you might have access to. The Remote Solve Manager (RSM) feature allows you to perform solutions on a remote machine. Once completed, results are transferred to your local machine for post processing. Refer to the Solve Modes and Recommended Usage section for more details.

Solution Progress Since nonlinear or transient solutions can take significant time to complete, a status bar is provided that indicates the overall progress of solution. More detailed information on solution status can be obtained from the Solution Information object which is automatically inserted under the Solution folder for all analyses. The overall solution progress is indicated by a status bar. In addition you can use the Solution Information object which is inserted automatically under the Solution folder. This object allows you to i) view the actual output from the solver, ii) graphically monitor items such as convergence criteria for nonlinear problems and iii) diagnose possible reasons for convergence difficulties by plotting Newton-Raphson residuals. Additionally you can also monitor some result items such as displacement or temperature at a vertex or contact region’s behavior as the solution progresses.

Solve References for the Mechanical Application See the «Understanding Solving» (p. 1023) section for details on the above and other topics related to solving. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Review Results The analysis type determines the results available for you to examine after solution. For example, in a structural analysis, you may be interested in equivalent stress results or maximum shear results, while in a thermal analysis, you may be interested in temperature or total heat flux. The «Using Results» (p. 857) section lists various results available to you for postprocessing. To add result objects in the Mechanical application: 1.

Highlight a Solution object in the tree.

2.

Select the appropriate result from the Solution context toolbar or use the right-mouse click option.

To review results in the Mechanical application: 1.

Click on a result object in the tree.

2.

After the solution has been calculated, you can review and interpret the results in the following ways: • Contour results — Displays a contour plot of a result such as stress over geometry. • Vector Plots — Displays certain results in the form of vectors (arrows). • Probes — Displays a result at a single time point, or as a variation over time, using a graph and a table. • Charts — Displays different results over time, or displays one result against another result, for example, force vs. displacement. • Animation — Animates the variation of results over geometry including the deformation of the structure. • Stress Tool — to evaluate a design using various failure theories. • Fatigue Tool — to perform advanced life prediction calculations. • Contact Tool — to review contact region behavior in complex assemblies. • Beam Tool — to evaluate stresses in line body representations.

Note Displacements of rigid bodies are shown correctly in transient structural and rigid dynamics analyses. If rigid bodies are used in other analyses such as static structural or modal analyses, the results are correct, but the graphics will not show the deformed configuration of the rigid bodies in either the result plots or animation.

Note If you resume a Mechanical model from a project or an archive that does not contain result files, then results in the Solution tree can display contours but restrictions apply: • The result object cannot show a deformed shape; that is, the node-based displacements are not available to deform the mesh.

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Create Report (optional) • The result object cannot animate. • Contours are not available for harmonic results that depend upon both real and imaginary result sets.

See the «Using Results» (p. 857) section for more references on results.

Create Report (optional) Workbench includes a provision for automatically creating a report based on your entire analysis. The documents generated by the report are in HTML. The report generates documents containing content and structure and uses an external Cascading Style Sheet (CSS) to provide virtually all of the formatting information.

Report References for the Mechanical Application See the Report Preview (p. 22) section.

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Analysis Types You can perform several types of analyses in the Mechanical application using pre-configured analysis systems (see Create Analysis System (p. 125)). For doing more advanced analysis you can use Commands objects in the Mechanical interface. This allows you to enter sMechanical APDL application commands in the Mechanical application to perform the analysis. If you are familiar with the Mechanical APDL application commands, you will have the capability of performing analyses and techniques that are beyond those available using the analysis systems in Workbench. This section describes the following analysis types that you can perform in the Mechanical interface. Available features can differ from one solver to another. Each analysis section assumes that you are familiar with the nature and background of the analysis type as well as the information presented in the «Steps for Using the Mechanical Application» (p. 125) section. Design Assessment Analysis Electric Analysis Explicit Dynamics Analysis Linear Dynamic Analysis Types Magnetostatic Analysis Rigid Dynamics Analysis Static Structural Analysis Steady-State Thermal Analysis Thermal-Electric Analysis Transient Structural Analysis Transient Structural Analysis Using Linked Modal Analysis System Transient Thermal Analysis Special Analysis Topics

Design Assessment Analysis Introduction The Design Assessment system enables the selection and combination of upstream results and the ability to optionally further assess results with customizable scripts. Furthermore it enables the user to associate attributes, which may be geometry linked but not necessarily a property of the geometry, to the analysis via customizable items that can be added in the tree. Finally, custom results can be defined from the script and presented in the Design Assessment system to enable complete integration of a post finite element analysis process. The scripting language supported is python based. The location of the script and the available properties for the additional attributes and results can be defined via an XML file which can be easily created in any text editor and then selected by right clicking on the Setup cell on the system. The Design Assessment system must be connected downstream of another analysis system (the allowed system types are listed below in Preparing the Analysis). An Assessment Type must be set for each Design Assessment system. Predefined scripts are supplied to interface with the BEAMCHECK and FATJACK products. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types

Points to Remember • The BEAMCHECK and FATJACK assessment types are not available on Linux. • Design Assessment is not supported on the SUSE 10 x64 platform.

Preparing the Analysis Create Analysis System Basic general information about this topic … for this analysis type: Because a design assessment analysis is a postprocessing analysis, one or more upstream analysis systems (at this time, limited to Static Structural, Transient Structural, Harmonic Response, Modal, Response Spectrum, Random Vibration, and Explicit Dynamics systems) are a required prerequisite. The requirement then is for two or more analysis systems, including a Design Assessment analysis system, that share resources, geometry, and model data. From the Toolbox, drag one of the allowed system templates to the Project Schematic. Then, drag a Design Assessment template directly onto the first template, making sure that all cells down to and including the Model cell are shared. If multiple upstream systems are included, all must share the cells above and including the Model cell. Define Engineering Data Basic general information about this topic … for this analysis type: There are no specific considerations for a design assessment analysis. Attach Geometry Basic general information about this topic … for this analysis type: There are no specific considerations for a design assessment analysis. Define Part Behavior Basic general information about this topic … for this analysis type: There are no specific considerations for a design assessment analysis. Define Connections Basic general information about this topic

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Design Assessment Analysis … for this analysis type: There are no specific considerations for a design assessment analysis. Apply Mesh Controls/Preview Mesh Basic general information about this topic … for this analysis type: There are no specific considerations for a design assessment analysis. Establish Analysis Settings Basic general information about this topic … for this analysis type: There are no specific considerations for a design assessment analysis. Define Initial Conditions Basic general information about this topic … for this analysis type: You must point to a structure analysis in the Initial Condition environment field. Apply Loads and Supports Basic general information about this topic … for this analysis type: There are no specific considerations for a design assessment analysis. Solve Basic general information about this topic … for this analysis type: Solution Information continuously updates any listing output from the Design Assessment log files and provides valuable information on the behavior of the structure during the analysis. The file solve.out is provided for log information from any external process your analysis may use. Solve script and Evaluate script log files are produced by the solve and evaluate Python processes respectively. Select the log information that you want to display from the Solution Output drop down. Review Results Basic general information about this topic

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Analysis Types … for this analysis type: The following Mechanical results are available when Solution Combination is enabled for the design assessment analysis: • Stress Tool • Fatigue Tool • Contact Tool (for the following contact results: Frictional Stress, Penetration, Pressure, and Sliding Distance) • Beam Tool • Beam Results • Stresses • Elastic Strains • Deformations The results available for insertion will depend on the types of the systems selected for combination and the setting of the Results Availability field in the Details panel of the Design Assessment Solution object in the tree. In addition, DA Result objects will be available if they are enabled for the design assessment analysis.

Note Not all of the standard right-click menu options are available for DA Result objects. Cut, Copy, Paste, Copy to Clipboard, Duplicate, Rename, and Export are removed.

Electric Analysis Introduction An electric analysis supports Steady-State Electric Conduction. Primarily, this analysis type is used to determine the electric potential in a conducting body created by the external application of voltage or current loads. From the solution, other results items are computed such as conduction currents, electric field, and joule heating. An Electric Analysis supports single and multibody parts. Contact conditions are automatically established between parts. In addition, an analysis can be scoped as a single step or in multiple steps. An Electric analysis computes Joule Heating from the electric resistance and current in the conductor. This joule heating may be passed as a load to a Thermal analysis simulation using an Imported Load if the Electric analysis Solution data is to be transferred to Thermal analysis. Similarly, an electric analysis can accept a Thermal Condition from a thermal analysis to specify temperatures in the body for material property evaluation of temperature-dependent materials.

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Electric Analysis

Points to Remember A steady-state electric analysis may be either linear (constant material properties) or nonlinear (temperature dependent material properties). Additional details for scoping nonlinearities are described in the Nonlinear Controls section. Once an Electric Analysis is created, Voltage and Current loads can be applied to any conducting body. For material properties that are temperature dependent, a temperature distribution can be imported using the Thermal Condition option. In addition, equipotential surfaces can be created using the Coupling Condition load option.

Preparing the Analysis Create Analysis System Basic general information about this topic … for this analysis type: From the Toolbox, drag the Electric template to the Project Schematic. Define Engineering Data Basic general information about this topic … for this analysis type: When an Emag license is being used only the following material properties are allowed: Isotropic Resistivity, Orthotropic Resistivity, Relative Permeability, Relative Permeability (Orthotropic), Coercive Force & Residual Induction, B-H Curve, B-H Curve (Orthotropic), Demagnetization B-H Curve. You may have to turn the filter off in the Engineering Data tab to suppress or delete those material properties/models which are not supported for this license. Attach Geometry Basic general information about this topic … for this analysis type: Note that 3D shell bodies and line bodies are not supported in an electric analysis. Define Part Behavior Basic general information about this topic … for this analysis type: There are no specific considerations for an electric analysis. Define Connections

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Analysis Types Basic general information about this topic … for this analysis type: In an electric analysis, only bonded, face-face contact is valid. Any joints or springs are ignored. For perfect conduction across parts, use the MPC formulation. To model contact resistance, use Augmented Lagrange or Pure Penalty with a defined Electric Conductance. Apply Mesh Controls/Preview Mesh Basic general information about this topic … for this analysis type: Only higher order elements are allowed for an electric analysis. Establish Analysis Settings Basic general information about this topic … for this analysis type: For an electric analysis, the basic controls are: Step Controls (p. 635): used to specify the end time of a step in a single or multiple step analysis. Multiple steps are needed if you want to change load values, the solution settings, or the solution output frequency over specific steps. Typically you do not need to change the default values. Output Controls (p. 658) allow you to specify the time points at which results should be available for postprocessing. A multi-step analysis involves calculating solutions at several time points in the load history. However you may not be interested in all of the possible results items and writing all the results can make the result file size unwieldy. You can restrict the amount of output by requesting results only at certain time points or limit the results that go onto the results file at each time point. Analysis Data Management (p. 664) settings. Define Initial Conditions Basic general information about this topic … for this analysis type: There is no initial condition specification for an Electric analysis. Apply Loads and Supports Basic general information about this topic … for this analysis type:

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Explicit Dynamics Analysis The following loads are supported in a Steady-State Electric analysis: • Voltage • Current • Coupling Condition (Electric) • Thermal Condition Solve Basic general information about this topic … for this analysis type: The Solution Information object provides some tools to monitor solution progress. Solution Output continuously updates any listing output from the solver and provides valuable information on the behavior of the model during the analysis. Any convergence data output in this printout can be graphically displayed as explained in the Solution Information section. Review Results Basic general information about this topic … for this analysis type: Applicable results are all electric result types. Once a solution is available, you can contour the results or animate the results to review the responses of the model. For the results of a multi-step analysis that has a solution at several time points, you can use probes to display variations of a result item over the steps. You may also wish to use the Charts feature to plot multiple result quantities against time (steps). For example, you could compare current and joule heating. Charts can also be useful when comparing the results between two analysis branches of the same model.

Explicit Dynamics Analysis Introduction You can perform a transient explicit dynamics analysis in the Mechanical application using an Explicit Dynamics system. Additionally, the Explicit Dynamics (LS-DYNA Export) system is available to export the model in LS-DYNA .k file format for subsequent analysis with the LS-DYNA solver. Unless specifically mentioned otherwise, this section addresses both the Explicit Dynamics and Explicit Dynamics (LS-DYNA Export) systems. Special conditions for the Explicit Dynamics (LS-DYNA Export) system are noted where pertinent.

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Analysis Types An explicit dynamics analysis is used to determine the dynamic response of a structure due to stress wave propagation, impact or rapidly changing time-dependent loads. Momentum exchange between moving bodies and inertial effects are usually important aspects of the type of analysis being conducted. This type of analysis can also be used to model mechanical phenomena that are highly nonlinear. Nonlinearities may stem from the materials, (for example, hyperelasticity, plastic flows, failure), from contact (for example, high speed collisions and impact) and from the geometric deformation (for example, buckling and collapse). Events with time scales of less than 1 second (usually of order 1 millisecond) are efficiently simulated with this type of analysis. For longer time duration events, consider using a Transient Structural Analysis (p. 285) system. This section contains the following topics: Using Explicit Dynamics to Define Initial Conditions for Implicit Analysis

Points to Remember An explicit dynamics analysis typically includes many different types of nonlinearities including large deformations, large strains, plasticity, hyperelasticity, material failure etc. The time step used in an explicit dynamics analysis is constrained to maintain stability and consistency via the CFL condition, that is, the time increment is proportional to the smallest element dimension in the model and inversely proportional to the sound speed in the materials used. Time increments are usually on the order of 1 microsecond and therefore thousands of time steps (computational cycles) are usually required to obtain the solution. • Explicit dynamics analyses only support the mm, mg, ms solver unit system. This will be extended to support more unit systems in a future release. • 2-D Explicit Dynamics analyses are supported for Plane Strain and Axisymmetric behaviors. • When attempting to use the Euler capabilities in the Explicit Dynamics analysis system, the following license restrictions are observed: – Set-up and solve of Euler capabilities in the Explicit Dynamics system are supported for the full ANSYS Autodyn (acdi_ad3dfull) license. – Set-up but not solve of Euler capabilities in the Explicit Dynamics system are supported for the pre-post ANSYS Autodyn (acdi_prepost) license. – Set-up or solve of Euler capabilities in the Explicit Dynamics system are not supported for the ANSYS Explicit STR (acdi_explprof ) license. – Euler capabilities are not supported for the Explicit Dynamics (LS-DYNA Export) system. • (Linux only) In order to run a distributed solution on Linux, you must add the MPI_ROOT environment variable and set it to the location of the MPI software installation. It should be of the form: {ANSYS installation}/commonfiles/MPI/Platform/{version}/{platform} For example: usr/ansys_inc/v150/commonfiles/MPI/Platform/9.1/linx64 • Consideration should be given to the number of elements in the model and the quality of the mesh to give larger resulting time steps and therefore more efficient simulations. • A coarse mesh can often be used to gain insight into the basic dynamics of a system while a finer mesh is required to investigate nonlinear material effects and failure. 156

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Explicit Dynamics Analysis • The quality of the solution can be monitored by reviewing momentum and energy conservation graphs in the solution output. Low energy errors (<10% of initial energy) are indicative of good quality solutions. • The Explicit Dynamics solver is double precision. • The Explicit Dynamics (LS-DYNA Export) system allows for an LS-DYNA input file (otherwise known as a “keyword” file or a “.k” file) to be exported. This keyword file contains all the necessary information available in the Mechanical application environment to carry out the analysis with the LS-DYNA solver. The exported keyword file follows the same format as the one exported by the respective Mechanical APDL application. All the LS-DYNA keywords are implemented according to the “LS_DYNA Keyword Users Manual” version 971. All the LS-DYNA keywords that can currently be exported are described in detail in Supported LSDYNA Keywords (p. 1617). Any parameters that are not shown for a card are not used and their default values will be assigned for them by the LS-DYNA solver. Some descriptions of Workbench features that do not relate directly to keywords are given under ”General Descriptions” located at the end of this appendix. Since only an input file is generated during solve of an Explicit Dynamics (LS-DYNA Export) system, the Background and Remote solve options are not supported. • When using Commands objects with the Explicit Dynamics (LS-DYNA Export) system, be aware of the following: – Keyword cards read from Commands object content (renamed to «Keyword» snippets for the Explicit Dynamics (LS-DYNA Export) system) should not have any trailing empty lines if they are not intentional. This is due to the fact that some keywords have more than one mandatory card that can be entered as blank lines, in which case the default values for the card will be used. Hence trailing blank lines can be significant only if required, otherwise they may cause solver execution errors. – The first entry in the Commands object content must be a command name which is preceded by the * symbol. – Refer to LS-DYNA General Descriptions (p. 1646) regarding ID numbers entered in Commands object content. An explicit dynamics analysis can contain both rigid and flexible bodies. For rigid/flexible body dynamic simulations involving mechanisms and joints you may wish to consider using either the Transient Structural Analysis (p. 285) or Rigid Dynamics Analysis (p. 216) options. For more information about explicit dynamics analyses, see Appendix G (p. 1771).

Note The intent of this document is to provide an overview of an explicit dynamics analysis. Consult our technical support department to obtain a more thorough treatment of this topic.

Preparing the Analysis Create Analysis System Basic general information about this topic

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Analysis Types … for this analysis type: From the Toolbox drag an Explicit Dynamics or an Explicit Dynamics (LS-DYNA Export) template to the Project Schematic. Define Engineering Data Basic general information about this topic … for this analysis type: Material properties can be linear elastic or orthotropic. Many different forms of material nonlinearity can be represented including hyperelasticity, rate and temperature dependant plasticity, pressure dependant plasticity, porosity, material strength degradation (damage), material fracture/failure/fragmentation. For a detailed discussion on material models used in Explicit Dynamics, refer to Appendix F (p. 1703). Density must always be specified for materials used in an explicit dynamics analysis. Data for a range of materials is available in the Explicit material library. For Explicit Dynamics (LS-DYNA Export) systems, only the following material models are supported (also see *MAT_ keywords in Supported LS-DYNA Keywords (p. 1617)). Any models that are not mentioned in this list can be entered through the «Keyword Snippet» facility (see the LS-DYNA General Descriptions section): • Strength models – Linear Elastic → Isotropic → Orthotropic – Plasticity → Bilinear Isotropic Hardening → Multilinear Isotropic Hardening → Bilinear Kinematic Hardening → Johnson Cook – Hyperelastic: → Mooney-Rivlin → Polynomial → Yeoh → Ogden

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Explicit Dynamics Analysis – Rigid (there is no entry for this in the Engineering Data workspace of Workbench. See *MAT_RIGID in Supported LS-DYNA Keywords (p. 1617) for more details). • Equation of state (EOS) models – Linear (there is no entry for this in the Engineering Data workspace of Workbench. See *EOS_LINEAR_POLYNOMIAL in Supported LS-DYNA Keywords (p. 1617) for more details). – Shock • Failure models – Plastic Strain – Johnson Cook

Note For line bodies, the LS-DYNA solver only supports the following three material properties from the above list: Isotropic Linear Elastic, Bilinear Kinematic Hardening Plasticity and Rigid bodies. Additional material models that are supported by the LS-DYNA solver for line bodies can be added through the «Keyword Snippet» facility. Attach Geometry Basic general information about this topic … for this analysis type: Solid, Surface, and Line bodies can be present in an Explicit Dynamics analysis. Only symmetric cross sections are supported for line bodies in Explicit Dynamics analyses, except for the Explicit Dynamics (LS-DYNA Export) systems. The following cross sections are not supported: T-Sections, L-Sections, Z-Sections, Hat sections, Channel Sections. For I-Sections, the two flanges must have the same thickness. For rectangular tubes, opposite sides of the rectangle must be of the same thickness. For LS-DYNA Export systems all available cross sections in DesignModeler will be exported for analysis with the LS-DYNA solver. However there are some limitations in the number of dimensions that the LSDYNA solver supports for the Z, Hat and Channel cross sections. For more information consult the LS-DYNA Keywords manual. To prevent the generation of unnecessarily small elements (and long run times) try using DesignModeler to remove unwanted “small” features or holes from your geometry. Thickness can be specified for selected faces on a surface body by inserting a thickness object. Constant, tabular, and functional thickness are all supported. Symmetry is not supported when exporting to the LS-DYNA .k file. Stiffness Behavior Flexible behavior can be assigned to any body type.

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Analysis Types Rigid behavior can be applied to Solid and Surface bodies. Coordinate System Local Cartesian coordinate systems can be assigned to bodies. These will be used to define the material directions when using the Orthotropic Elasticity property in a material definition. The material directions 1, 2, 3 will be aligned with the local x, y and z axes of the local coordinate system.

Note Cylindrical coordinate systems are not supported for Explicit Dynamics systems. Reference Temperature This option defines the initial (time=0.0) temperature of the body. Reference Frame Available for solid bodies when an Explicit Dynamics system is part of the solution; the user has the option of setting the Reference Frame to Lagrangian (default) or Eulerian (Virtual). If Stiffness Behavior is defined as Rigid, Eulerian is not a valid setting. Rigid Materials For bodies defined to have rigid stiffness, only the Density property of the material associated with the body will be used. For Explicit Dynamics systems all rigid bodies must be discretized with a Full Mesh. This will be specified by default for the Explicit meshing physics preference. The mass and inertia of the rigid body will be derived from the elements and material density for each body. By default, a kinematic rigid body is defined and its motion will depend on the resultant forces and moments applied to it through interaction with other Parts of the model. Elements filled with rigid materials can interact with other regions via contact. Constraints can only be applied to an entire rigid body. For example, a fixed displacement cannot be applied to one edge of a rigid body, it must be applied to the whole body.

Note • Only symmetric cross-sections are supported for line bodies • Flexible and rigid bodies cannot be combined in Multi-body Parts. Bonded connections can be applied to connect rigid and flexible bodies • The Thickness Mode and Offset Type fields for surface bodies are not supported for Explicit Dynamics systems • Initial over-penetrations of nodes/elements of different bodies should be avoided or minimized if sliding contact is to be used. There are several methods available in Workbench to remove initial penetration

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Explicit Dynamics Analysis Define Part Behavior Basic general information about this topic … for this analysis type: Nonlinear effects are always accounted for in explicit dynamics analysis. Parts may be defined as rigid or flexible. In the solver, rigid parts are represented by a single point that carries the inertial properties together with a discretized exterior surface that represents the geometry. Rigid bodies should be meshed using similar Method mesh controls as those used for flexible bodies. The inertial properties used in the solver will be derived from the discretized representation of the body and the material density and hence may differ slightly from the values presented in the properties of the body in the Mechanical application GUI. At least one flexible body must be specified when using the ANSYS Autodyn solver. The solver requires this in order to calculate the time-step increments. In the absence of a flexible body, the time-step becomes underdefined. The boundary conditions allowed for the rigid bodies with explicit dynamics are: • Connections – Contact Regions: Frictionless, Frictional and Bonded. – Body Interactions: Frictionless, Frictional and Bonded. Bonded body interactions are not supported for LS-DYNA Export. – For ANSYS Autodyn, rigid bodies may not be bonded to other rigid bodies. • Initial Conditions: Velocity, Angular Velocity • Supports: Displacement, Fixed Support and Velocity. • Loads: Pressure and Force. Force is not supported for ANSYS Autodyn. For an Explicit Dynamics analysis, the following postprocessing features are available for rigid bodies: • Results and Probes: Deformation only — that is, Displacement, Velocity. • Result Trackers: Body average data only. If a multibody part consists only of rigid bodies, all of which share the same material assignment, the part will act as a single rigid body, even if the individual bodies are not physically connected. Define Connections Basic general information about this topic … for this analysis type: Line body to line body contact is possible if:

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Analysis Types • Contact Detection should be set to Proximity Based in the Body Interactions Details view. • Edge on Edge is set to Yes in the Body Interactions Details view. • The Interaction Type is defined as Frictional or Frictionless – bonded interactions and connections are not supported for line bodies. • LS-DYNA Export systems export the *CONTACT_AUTOMATIC_GENERAL and *CONTACT_AUTOMATIC_SINGLE_SURFACE keywords when a friction or frictionless Body Interaction is scoped to geometry that contains line bodies. The keywords handle contacts between line bodies only, and line bodies to other body types respectively. In the case where the Body Interaction is scoped to only line bodies, then only the *CONTACT_AUTOMATIC_GENERAL keyword is exported. Reinforcement body interaction should be supported in the case when only line bodies are scoped to a Body Interaction of Type = Reinforcement. The line bodies will then be tied to any solid body that they intersect. Reinforcement body interactions are not supported for LS-DYNA Export systems or for 2D Explicit Dynamics analyses. However utilizing Keyword Snippets under Contact Region objects should provide a suitable alternative. Body Interactions, Contact and Spot Welds are all valid in explicit dynamics analyses. Frictional, Frictionless and Bonded body interactions and contact options are available. Conditionally bonded contact can be simulated using the breakable property of each bonded region. Spot Welds can also be made to fail using the breakable property. Joints and Beam connections are not supported for explicit dynamics analyses. Springs are not supported for Explicit Dynamics (LS-DYNA Export) analyses. The Contact Tool is also not applicable to explicit dynamics analyses. By default, a Body Interaction object will be automatically inserted in the Mechanical application tree and will be scoped to all bodies in the model. This object activates frictionless contact behavior between all bodies that come into proximity during the analysis. For Explicit Dynamics (LS-DYNA Export) systems, bonded body interactions are not supported. Also, Contact Region objects with Auto Asymmetric Behavior or just Asymmetric Behavior are treated the same. Symmetric Behavior will create a _SURFACE_TO_SURFACE keyword for the contact and an Asymmetric Behavior will create a _NODES_TO_SURFACE keyword. For Explicit Dynamics (LS-DYNA Export) systems, contacts between line bodies and solids can be implemented using the Keyword Snippets facility available under the Manual Contact Region objects. Bonded contact is not supported in an explicit dynamics analysis for bodies that have their Reference Frame set to Eulerian (Virtual). A solver warning is shown to let the user know that such bodies will be ignored for bonds. Bonded contact is not support in a 2D explicit dynamics analysis. To avoid hourglassing problems, remote points should be used instead of bonded contact in certain situations.

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Explicit Dynamics Analysis Bonds are not recommended for joining tetrahedral meshes. Use multibodied parts or remote points instead. Setting Up Symmetry Basic general information about this topic … for this analysis type: There are general considerations when using Symmetry for an Explicit Dynamics Analysis. There are additional considerations if an Euler Domain is defined for an analysis. For symmetry to be applied to an Euler Domain, symmetry will have to be defined with the global coordinate system, not a local one, and it will need to be applied on geometry faces which lie on the global coordinate system planes. • If the symmetry is not defined with the global coordinate system, it is ignored and a warning is shown in the messages window saying that such symmetry will be ignored but the analysis continues to solve. • If the symmetry is not applied on faces which lie on the global coordinate system planes then an error is shown and the solution is terminated. In the case where symmetry is valid for use with Euler Domains, if the boundary of the Euler Domain which is parallel to the symmetry plane is bellow the symmetry plane, then that boundary will be moved to lie on the symmetry plane if the following conditions are true: • the Euler Domain Size Definition option in the Analysis settings is set to Program Controlled. • the Euler body is on the positive side of the global coordinate axis. Define Remote Points Basic general information about this topic … for this analysis type: When using Remote Points in Explicit Dynamics analyses: • Remote Points only work with the Explicit Dynamics system, not the Explicit Dynamics (LSDYNA Export) system. • The Behavior field must be set to Rigid. If it is set to Deformable the solution will terminate and an error will be generated. • Currently, only the remote displacement boundary condition is supported for Remote Points in Explicit Dynamics analyses. • Commands are not supported for Remote Points in Explicit Dynamics analyses. • Remote Points are not supported for 2D Explicit Dynamics analyses.

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Analysis Types It is possible to over-constrain bodies by having an incorrect mix of boundary conditions (loads and supports) and Remote Points applied. Remote Points effectively make a face act as rigid, and it is important to remember that remote points are defined per model and therefore may conflict when shared with another analysis type with different constraint requirements. Remote displacements are boundary conditions but are applied to remote points, and for the purpose of this document are not considered as constraining boundary conditions. Constraining boundary conditions (Restricted Fixed Support Use) Velocity Simply Supported Fixed Rotation Displacement Gravity Hydrostatic Pressure Detonation Point Examples of permitted boundary conditions (Unrestricted Use)

Pressure Acceleration Force Symmetry Planes Euler Boundary Flow Out Line Pressure

Remote point applied boundary conditions

Remote Displacement (treated as a Velocity)

The following rules apply when applying constraints and Remote Points to Flexible and Rigid Bodies in an Explicit Dynamics analysis. If incompatible conditions are applied, the pre-solve checks will identify the problem and inform the user prior to starting the Solve. FLEXIBLE BODY Example

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Conditions

Allowed? + Notes

Remote Point applied to one face.

Yes

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Explicit Dynamics Analysis FLEXIBLE BODY Example

Conditions

Allowed? + Notes

Remote Point and Remote Displacement Yes applied to one face.

Remote Point applied to two adjacent faces.

No The 2 faces share common nodes along one edge.

Remote Point applied to two faces that do not share any nodes.

Yes

Remote Point applied to two faces that do not share any nodes, with Remote Displacement applied to one of the Remote Points.

Yes

Remote Point on one face with Remote Displacement applied. Constraining boundary condition applied to adjacent face.

No

Remote Point on one face. Constraining boundary condition applied to adjacent face.

The boundary condition scope shares nodes with the scope of the Remote Displacement. No The boundary condition scope shares nodes with the scope of the Remote Point.

Remote Point on one face. Constraining Yes boundary condition on another but with no common scoped nodes.

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Analysis Types FLEXIBLE BODY Example

Conditions

Allowed? + Notes

Remote Point on one face with Remote Yes Displacement applied. Constraining boundary condition on another but with no common scoped nodes.

RIGID BODY Example

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Conditions

Allowed? + Notes

Remote Point applied to one face.

Yes This is largely superfluous as the body is rigid already so making the face rigid does not make any difference.

Remote Point and Remote Displacement applied to one face.

Yes

Remote Point applied to two adjacent faces.

Yes

Remote Point applied to two faces that do not share any nodes.

Yes

Remote Point applied to two faces that do not share any nodes, with Remote Displacement applied to one of the Remote Points.

Yes

Remote Point on one face. Constraining boundary condition on body.

Yes

This is largely superfluous as the body is rigid already so making the face rigid does not make any difference.

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Explicit Dynamics Analysis RIGID BODY Example

Conditions

Allowed? + Notes

Remote Point on one face with Remote Displacement applied. Constraining boundary condition on body.

No Two constraining boundary conditions on a Rigid body are not allowed.

Apply Mesh Controls/Preview Mesh Basic general information about this topic … for this analysis type: All mesh methods available in the Workbench meshing application can be utilized in Explicit Dynamics systems. • Swept Volume Meshing • Patch Dependant Volume Meshing • Hex Dominant Meshing • Patch Independent Tetrahedral Meshing • Multizone Volume Meshing • Patch dependant shell meshing • Patch independent shell meshing A smooth uniform mesh should be sought in the regions of interest for the analysis. Elsewhere, coarsening of the mesh may help to reduce the overall size of the problem to be solved. Use the Explicit meshing preference (set by default) to auto-assign the default mesh controls that will provide a mesh well suited for Explicit Dynamics analyses. This preference automatically sets the Rigid Body Behavior mesh control to Full Mesh. The Full Mesh setting is only applicable to Explicit Dynamics analyses. Other physics preferences can be used if better consistency is desired between implicit and explicit models. Swept/multi-zone meshes are preferred in Explicit Dynamics analyses so geometry slicing, combined with multibody part options in DesignModeler are recommended to facilitate hexahedral meshing. Alternatively use the patch independent tetrahedral meshing method to obtain more uniform element sizing and take advantage of automatic defeaturing. Define the element size manually to produce more uniform element size distributions especially on surface bodies. Midside nodes should be dropped from the mesh for all elements types (solids, surface and line bodies). Error/warning messages are provided if unsupported (higher order) elements are present in the mesh.

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Analysis Types Pyramid elements are not supported in Explicit Dynamics analyses. Any elements of this type are converted into two tetrahedral elements, and will warrant a warning in the message window of the Mechanical application. For Explicit Dynamics (LS-DYNA Export) systems, only the element types listed below are supported (partly due to LS-DYNA limitations). Any parts with a mesh containing unsupported elements will be excluded from the exported mesh. A warning is displayed specifying excluded parts. • Shells – 1st Order: triangles, quadrilaterals – 2nd Order: none • Solids – 1st Order: tetrahedrons, pyramids, wedges, hexahedrons, beams – 2nd Order: tetrahedrons

Note Pyramids are not recommended for LS-DYNA. A warning is issued if such elements are present in the mesh. When performing an implicit static structural or transient structural analysis to an Explicit Dynamics analysis, the same mesh is required for both the implicit and explicit analysis and only low order elements are allowed. If high order elements are used, the solve will be blocked and an error message will be issued. Establish Analysis Settings Basic general information about this topic … for this analysis type: The basic analysis settings for explicit dynamics analyses are: • Step Controls — The required input for step control is the termination time for the analysis. This should be set to your best estimate of the solution time required to simulate the event being modeled. You should normally allow the solver to determine its own time step size based on the smallest CFL condition in the model. The efficiency of the solution can be increased with the help of mass scaling options. Use this feature with caution. Too much mass scaling can give rise to non-physical results. An explicit dynamics solution may be started, interrupted and resumed at any point in time. For example, an existing solution that has reached its End Time may be extended to continue to review the progression of the mechanical phenomena simulated. The Resume From Cycle option allows you to select which Restart file you would like the Solve to resume the analysis from. See Resume Capability for Explicit Dynamics Analyses (p. 1136) for more information. Explicit dynamics analyses are always solved in a single analysis step.

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Explicit Dynamics Analysis Step Control options – Resume from cycle (option not available in LS-DYNA) – Maximum Number of Cycles in ANSYS Autodyn is replaced by Maximum time steps in LS-DYNA – Reference energy cycle (option not available in LS-DYNA) – The Maximum Element Scaling and Update frequency (options not available in LS-DYNA) • Solver Controls – These advanced controls allow you to control a range of solver features including element formulations and solution velocity limits. The defaults are applicable to wide range of applications. – Shell thickness update, shell inertia update, density update, minimum velocity, maximum velocity and radius cutoff options can only be set in ANSYS Autodyn. – Full shell integration and a selectable Unit System are available only in the LS-DYNA Export system. • Euler Domain Controls – There are three sets of parameters that are necessary to define the Euler Domain: the size of the whole domain (Domain Size Definition), the number of computational cells in the domain (Domain Resolution Definition), and the type of boundary conditions to be applied to the edges of the domain.

Note Euler capabilities are not supported for the Explicit Dynamics (LS-DYNA Export) system. The domain size can be defined automatically (Domain Size Definition = Program Controlled) or manually (Domain Size Definition = Manual). For both the automatic and manual options, the size is defined from a 3D origin point and the X, Y, and Z dimensions of the domain. For the automatic option, specify the Scope of the Domain Size Definition so that the origin and X, Y, and Z dimensions are set to create a box large enough to include all bodies in the geometry (Scope = All Bodies) or the Eulerian Bodies only (Scope = Eulerian Bodies Only). The automatically determined domain size can be controlled with three scaling parameters, one for each direction (X Scale Factor, Y Scale Factor, Z Scale Factor). The size of the domain is affected by the scale factors according to the following equations:

′ = 
   ′ =    ′=



(1) (2)

 

(3)

where

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Analysis Types lx, ly, lz are the lengths of the unscaled domain in the x, y, and z directions respectively. These parameters are obtained automatically from the mesh. l’x, l’y, l’z are the lengths of the scaled domain in the x, y, and z directions respectively. Fx, Fy, Fz are the scale factors for the x, y, and z directions respectively. For the Manual option of the Domain Size Definition, specify the origin of the Euler Domain (Minimum X Coordinate, Minimum Y Coordinate, Minimum Z Coordinate) and the dimension in each direction (X Dimension, Y Dimension, Z Dimension). The domain resolution specifies how many cells should be created in the X, Y, and Z directions of the domain. Use the Domain Resolution Definition field to specify how to determine the resolution: either the cell size (Cell Size), the number of cells in each of the X, Y, and Z directions (Cells per Component), or the total number of cells to be created (Total Cells). – For the Cell Size option, specify the size of the cell in the Cell Size parameter. The value specified is the dimension of the cell in each of the X, Y, and Z directions. The units used for the cell size follow the ones specified in the Mechanical application window and are displayed in the text box. The number of the cells in each direction of the domain are then determined from this cell size and the size of the domain with the following equations:

 =    =    = 

(4) (5) (6)

where Nx, Ny, Nz are the number of cells in the X, Y, and Z directions respectively. D is the dimension of the cell in each direction (this is the same in all directions). – For the Cells per Component option, enter the number of cells required in each of the X, Y, and Z directions (Number of Cells in X, Number of Cells in Y, Number of Cells in Z). – For the Total Cells option, specify Total Cells (the default is 250,000). The size of the cells will depend on the size of the Euler Domain. The size of the cell is calculated from the following equation:



      =      where Ntot is the total number of cells in the domain.

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Explicit Dynamics Analysis If any bodies are defined as Eulerian (Virtual), when Analysis Settings is selected in the outline view, the Euler domain bounding box is displayed in the graphics window. The Euler domain resolution is indicated by black node markers along each edge line of the Euler domain. The visibility of this can be controlled by the Display Euler Domain option in the Analysis Settings. You can set boundary conditions on each of the faces of the Euler Domain. The faces are labeled Lower X Face, Lower Y Face, Lower Z Face (which correspond to the faces with the minimum X, Y, and Z coordinates) and Upper X Face, Upper Y Face, and Upper Z Face (which correspond to the faces with the maximum X, Y, and Z coordinates). The values of the boundary conditions that can be set for each face are: – Flow Out Use the Flow Out boundary condition to flow out material through cell faces. The boundary condition makes the material state of the dummy cell outside the Euler domain the same as that of the cell adjacent to the Flow Out boundary, thus setting the gradients of velocity and stress to zero over the boundary. This approach simulates a far field solution at the boundary, but is only exact for outflow velocities higher than the speed of sound and is an approximation for lower velocities. Therefore, the Flow Out boundary condition is approximate in many cases, and should be placed as far as possible from region of interest and best at a location where the gradients are small. – Impedance Use the Impedance boundary condition to transmit waves through cell faces without reflection. The boundary condition predicts the pressure P in the dummy cell outside the Euler domain from the impedance, particle velocity, and the pressure of the cell adjacent to the Impedance boundary. Only the perpendicular component of the wave is transmitted without reflection. Therefore, the Impedance boundary condition is only approximate, and should be placed as far as possible from region of interest. – Rigid Use the Rigid boundary condition to prevent flow of material through cell faces. The cell faces are closed for material transport and act as rigid non-slip walls. The Rigid boundary condition takes the material state of the dummy cell outside the Euler domain as a mirrored image of the cell adjacent to the Wall boundary, thus setting the normal material velocity at the rigid wall to zero and leaving the tangential velocity unaffected. Euler Tracking is currently only By Body, which scopes the results to Eulerian bodies in the same manner as Lagrangian bodies. • Damping Controls – Damping is used to control oscillations behind shock waves and reduce hourglass modes in reduced integration elements. These options allow you to adapt the levels of damping, and formulation used for the analysis being conducted. Elastic oscillations in the solution can also be automatically damped to provide a quasi-static solution after a dynamic event. For Hourglass Damping, only one of either the Viscous Coefficient or Stiffness Coefficient, is used for the Flanagan Belytschko option — when running an explicit Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types dynamics analysis using the LS-DYNA solver, LS-DYNA does not allow for two coefficients to be entered in *CONTROL_HOURGLASS. Thus the non-zero coefficient determines the damping format to be either “Flanagan-Belytschko viscous” or “FlanaganBelytschko stiffness”, accordingly. If both are non-zero, the Stiffness Coefficient will be used.

Note Linear Viscosity in Expansion options are available only for ANSYS Autodyn. Hourglass damping in LS-DYNA is standard by default; in ANSYS Autodyn the same control is AUTODYN Standard.

• Erosion Controls – Erosion is used to automatically remove highly distorted elements from an analysis and is required for applications such as cutting and impact penetration. In an explicit dynamics analysis, erosion is a numerical tool to help maintain large time steps, and thus obtain solutions in appropriate time scales. Several options are available to initiate erosion. The default settings will erode elements which experience geometric strains in excess of 100%. The default value should be increased when modeling hyperelastic materials. Geometric strain limit and material failure criteria are not present in LSDYNA. • Output Controls – Solution output is provided in several ways: – Results files which are used to provide nodal and element data for contour and probe results such as deformation, velocity, stress and strain. Note that probe results will provide a filtered time history of the result data due to the relatively infrequent saving of results files. – Restart files should be stored less frequently than results files and can be used to resume an analysis. – Tracker data is usually stored much more frequently than results or restart data and thus is used to produce full transient data for specific quantities. – Output controls to save result tracker and solution output are not available for LS-DYNA. – When performing an implicit to explicit analysis, for a nonlinear implicit analysis, the Strain Details view property must be set to Yes because plastic strains are needed for the correct results. Define Initial Conditions Basic general information about this topic … for this analysis type: • You can define translational or angular velocity to a single body or to multiple bodies. In an explicit dynamics analysis, by default, all bodies are assumed to be at rest with no external constraint or load applied. It is not a requirement to apply these types of initial conditions to a body.

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Explicit Dynamics Analysis • An explicit dynamics solve can be performed if the model contains at least one initial condition (translational or angular velocity), or a non-zero constraint (displacement or velocity), or a valid load. • You can use the results of an implicit analysis as a pre-stress initial condition for an explicit dynamics analysis. For more information, see Applying Pre-Stress Effects for Explicit Analysis (p. 140). Apply Loads and Supports Basic general information about this topic … for this analysis type: • You can apply the following loads and supports in an explicit dynamics analysis: – Acceleration (p. 694) – Standard Earth Gravity (p. 698) – Pressure (p. 705) – Hydrostatic Pressure (p. 712) – Force (p. 716) – Line Pressure (p. 737) – Fixed Supports (p. 789) – Displacements (p. 791) – Displacements (p. 791) – Displacements (p. 791) – Detonation Point (p. 784) – Velocity (p. 798) – Impedance Boundary (p. 800) – Simply Supported (p. 809) – Fixed Rotation (p. 811) – Remote Displacement (p. 794) • Cylindrical coordinate systems are supported to define a single rotational displacement or velocity constraint on a rigid or flexible body. These coordinate systems are fixed, that is, they do not move with the body. • For Explicit Dynamics analyses, the y component (that is, Θ direction) of a velocity constraint defined with a cylindrical coordinate system has units of angular velocity.

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Analysis Types • For Explicit Dynamics analyses, the y component (that is, Θ direction) of a displacement constraint defined with a cylindrical coordinate system has units of rotation. • Step or time varying tabular loads can be applied in an explicit dynamics analysis. However, explicit dynamics does not support tabular data to specify the magnitude or components of Accelerations or Line Pressures. • For Explicit Dynamics analyses, functionally defined loads are supported for Pressure and Velocity but only when defined as varying in time. See «Setting Up Boundary Conditions» (p. 691). • For Explicit Dynamics (LS-DYNA) analyses, functionally defined loads are not supported. • Loads must be applied in a single step. • Loads and supports are not valid when applied to bodies having a Reference Frame of Eulerian (Virtual). • Detonation Points are only available for 3D Explicit Dynamics analyses, not for Explicit Dynamics (LS-DYNA Export) or 2D Explicit Dynamics analyses. • For Explicit Dynamics analyses, if multiple constraints (for example, displacements) are applied to a node then they must use the same coordinate system. This restriction is especially applicable at nodes on a shared topology such as an edge, where two adjacent faces, each with different constraints, may come together. These constraints must use the same coordinate system in their specification. • In the LS-DYNA solver, a Velocity or Displacement boundary condition (implemented with the *BOUNDARY_PRESCRIBED_MOTION keyword) will override a Fixed Support or a Simple Support or a Fixed Rotation boundary condition (implemented with the *BOUNDARY_SPC keyword). Hence if a body has a Velocity constraint and a Fixed Support applied to it, the whole body will move in the direction of the applied velocity. • The default unconstrained body is valid. It is not a requirement to constrain any DOF of a body In Explicit Dynamics systems. • An Explicit Dynamics solve can be performed if the model contains at least one Initial Condition (Translational or Rotational velocity) or a non-zero constraint (displacement or velocity) or a valid load. • The Remote Displacement boundary condition only works with the Explicit Dynamics system for 3D analyses, not the Explicit Dynamics (LS-DYNA Export) system or 2D Explicit Dynamics analyses. • A Remote Displacement boundary condition must have the Behavior field set to Rigid for an Explicit Dynamics analysis. An error will be reported if it is set to Deformable. If the Remote Displacement object is scoped to a Remote Point that has its Behavior set to Rigid, the Remote Displacement Behavior will automatically be set to Rigid also. Solve Basic general information about this topic … for this analysis type:

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Explicit Dynamics Analysis • Solution output – The Solution Information object provides a summary of the solution time increments and progress is continuously updated in the solution output. For distributed analyses, the parallel load balancing is also displayed. This is calculated for each slave as the CPU time taken on the slave divided by the average CPU time taken on all the slaves. For a perfectly balanced solution, all slaves will have a load balancing of one. Histograms of time step, energy and momentum are also available for real time monitoring of solution progress. – Choose Tools> Solve Process Settings to solve in the background either locally or remotely. Retrieve results while the analysis is running to get immediate feedback on progress and accuracy of the solution.

Note If you choose the My Computer, Background setting, it is necessary that you also click the Advanced… button and check Use Shared License, if possible, to obtain a successful solution.

• Result Tracker – Full transient time history data can be viewed after the insertion of Result Tracker objects. Body averaged data such as momentum and energy can be selected for display. Data at a specific location (position, velocity, stress etc.) can also be displayed. – The frequency at which Result Tracker information is provided is defined in the Save Result Tracker Data On option of the analysis settings. • Solve an Explicit Dynamics (LS-DYNA Export) system to produce the LS-DYNA keyword file. This can be used to directly solve with the LS-DYNA solver, outside of the Workbench environment. Review Results Basic general information about this topic … for this analysis type: • The following structural result types are available as results of an explicit dynamic analysis: – Deformation (p. 879) – Stress and Strain (p. 882) – Energy (Transient Structural and Rigid Dynamics Analyses) (p. 936) – Stress Tools (p. 904) – Structural Probes (p. 926) — Limited to: Deformation, Strain, Stress, Position, Velocity, Acceleration.

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Analysis Types • Once a solution is available you can display contour results or animate them to review the response of the structure through time.

Note For an explicit dynamics analysis, there is no results interpolation between the results sets. Specifying a time in the GUI will display results for the closest results set.

• Eroded nodes can be toggled on or off in the graphics display. • Probes can be used to display the variation in specific results over the saved time points in the analysis. The frequency at which data is available is defined in the Save Results On option of the analysis settings. This data should be specified prior to a solve. • You can use a Solution Information object to track, monitor, or diagnose problems that arise during a solution. • Additional results specific to an explicit dynamics analysis are available via User Defined Results for Explicit Dynamics Analyses (p. 983). • The Explicit Dynamics (LS-DYNA Export) system does not support the ability to review the results of a simulation using the LS-DYNA solver. Nevertheless results can be viewed with the lsprepost.exe application available at the ANSYS installation folder under ANSYS Inc\v150\ansys\bin\.

Using Explicit Dynamics to Define Initial Conditions for Implicit Analysis It is possible to initialize a Mechanical APDL implicit analysis from the results of an Explicit Dynamics analysis by using features of the Mechanical APDL command language. You can obtain results from the explicit analysis by using an Explicit Dynamics Workbench system followed by a Design Assessment system that uses a python script to extract the results and write the additional Mechanical APDL commands to a file. A Commands object can be added to the Transient or Static Structural system to include the execution of the Mechanical APDL commands from the file. A full description of the process follows, and an example has been detailed in the Design Assessment documentation.

Note This method is currently limited to cases where there is no change in mesh topology between the start of both the explicit and implicit analyses.

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Explicit Dynamics Analysis

Follows these steps to perform the explicit-to-implicit analysis: 1. Add an Explicit Dynamics analysis to the Workbench Project Schematic. 2. Add a Design Assessment system to the Explicit Dynamics system in the Project Schematic. You will create an XML Definition File for the Design Assessment system that specifies a python script to be run on “solve”. Set your Design Assessment type to be User Defined, and choose the XML Definition File that you created. 3. Create the python script to write to a file the necessary Mechanical APDL commands to initialize the implicit model. The script should: a. Get nodal deformations, stresses, and plastic strains from the end of the Explicit Dynamics analysis using the Design Assessment API. b. Write the Mechanical APDL commands: i.

Enter the preprocessor. Command(s): /PREP7

ii. Get initial nodal locations from the implicit analysis. Command(s): *GET, and so on iii. Redefine implicit elements to the deformed configuration by adding values from steps 3(a) and 3(b)(ii). Command(s): N, and so on iv. Specify reduced element integration if using solid elements. Workbench automatically converts explicit elements to implicit elements. However, due to explicit elements having only one integration point per element, it is necessary to specify this manually for the implicit elements in order that results can be transferred between the two analyses.

Note Explicit uses SHELL163 for shells and SOLID164 for solids. These get automatically converted to SHELL181 and SOLID185 respectively. Command(s): ET, 1, 185, , 1 and so on Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types v. Reenter the solution processor. Command(s): /SOLU vi. Set any necessary constraints on the model by modifying or adding to the boundary conditions defined during the explicit analysis (for example, in a metal forming analysis, you need to constrain the blank). Command(s): D, and so on vii. Import stresses from the Explicit Dynamics analysis. For solids, this will be one set of values per element. For shells, this will be one set of values for every layer within each element. Command(s): INISTATE , SET, DTYPE, STRESS Command(s): INISTATE , DEFINE, and so on viii.Import plastic strains and accumulated equivalent plastic strain from Explicit Dynamics analysis Command(s): INISTATE, SET, DTYPE, EPPL Command(s): INISTATE, DEFINE, and so on Command(s): INISTATE, SET, DTYPE, PLEQ Command(s): INISTATE, DEFINE, and so on ix. Solve analysis. Command(s): SOLVE 4. Add an implicit system, either Static Structural or Transient Structural. In this system include the file that was created with the Design Assessment script by adding a Commands object that reads in the file that was created by the python script. Command(s): /INPUT, and so on 5. When post processing, view results by issuing Mechanical APDL commands in order to view results with the initial deformed mesh. When post processing in the standard Workbench view, results will appear to deform in the opposite direction to the Explicit Dynamics analysis because it has not taken into account the redefined deformed mesh. To create graphic files showing the correctly deformed mesh, add a new Commands object under the Solution branch of the implicit analysis. Command(s): /SHOW, PNG Command(s): PLNSOL, and so on 6. When using shell elements, another step must be included in order to view the results. Shells only accept INISTATE in the element coordinate system and so when the stresses are initialized, they are not in the global coordinate system. Therefore, in order to view the results correctly, you must first change the solution to plot the results in the solution coordinate system. Command(s): /VIEW, , , -1 Command(s): /SHOW, PNG

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Linear Dynamic Analysis Types Command(s): PLNSOL, and so on

Linear Dynamic Analysis Types Applying external forces gradually to a structure does not cause it to experience any pulse or motion. You can solve structural responses with a simple static equilibrium analysis. That is, the structural elasticity forces and the external forces equilibrate one another. In reality, however, structures are subject to rapidly applied forces (or so-called dynamic forces), e.g., high-rise buildings, airplane wings, and drilling platforms are subject to wind gusts, turbulences, and ocean waves, respectively. These structures are in a state of motion as a result of the dynamic forces. To simulate and solve for the structural responses in a logical manner, a dynamic equilibrium analysis, or a dynamic analysis, is desirable. In a dynamic analysis, in addition to structural elasticity force, structural inertia and dissipative forces (or damping) are also considered in the equation of motion to equilibrate the dynamic forces. Inertia forces are a product of structural mass and acceleration while dissipative forces are a product of a structural damping coefficient and velocity. When performing a linear dynamic analysis, the application calculates structural responses based the assumption that a structure is linear. The following sections discuss the steps and requirements to perform different linear dynamic simulations. Harmonic Response Analysis Harmonic Response (Full) Analysis Using Pre-Stressed Structural System Harmonic Response Analysis Using Linked Modal Analysis System Linear Buckling Analysis Modal Analysis Random Vibration Analysis Response Spectrum Analysis

Harmonic Response Analysis Harmonic analyses are used to determine the steady-state response of a linear structure to loads that vary sinusoidally (harmonically) with time, thus enabling you to verify whether or not your designs will successfully overcome resonance, fatigue, and other harmful effects of forced vibrations.

Introduction In a structural system, any sustained cyclic load will produce a sustained cyclic or harmonic response. Harmonic analysis results are used to determine the steady-state response of a linear structure to loads that vary sinusoidally (harmonically) with time, thus enabling you to verify whether or not your designs will successfully overcome resonance, fatigue, and other harmful effects of forced vibrations. This analysis technique calculates only the steady-state, forced vibrations of a structure. The transient vibrations, which occur at the beginning of the excitation, are not accounted for in a harmonic analysis. In this analysis all loads as well as the structure’s response vary sinusoidally at the same frequency. A typical harmonic analysis will calculate the response of the structure to cyclic loads over a frequency range (a sine sweep) and obtain a graph of some response quantity (usually displacements) versus frequency. “Peak” responses are then identified from graphs of response vs. frequency and stresses are then reviewed at those peak frequencies.

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Analysis Types

Points to Remember A Harmonic Analysis is a linear analysis. Some nonlinearities, such as plasticity will be ignored, even if they are defined. All loads and displacements vary sinusoidally at the same known frequency (although not necessarily in phase). If the Reference Temperature is set as By Body and that temperature does not match the environment temperature, a thermally induced harmonic load will result (from the thermal strain assuming a nonzero thermal expansion coefficient). This thermal harmonic loading is ignored for all harmonic analysis. Mechanical offers the following solution methods for harmonic analyses: Mode Superposition (default) For the Mode Superposition (MSUP) method, the harmonic response to a given loading condition is obtained by performing the necessary linear combinations of the eigensolutions obtained from a Modal analysis. For MSUP, it is advantageous for you to select an existing modal analysis directly (although Mechanical can automatically perform a modal analysis behind the scene) since calculating the eigenvectors is usually the most computationally expensive portion of the method. In this way, multiple harmonic analyses with different loading conditions could effectively reuse the eigenvectors. For more details, refer to Harmonic Response Analysis Using Linked Modal Analysis System (p. 189). Full Using the Full method, you obtain harmonic response through the direct solution of the simultaneous equations of motion. In addition, a Harmonic Response analysis can be linked to, and use the structural responses of, a Static-Structural analysis. See the Harmonic Analysis Using Pre-Stressed Structural System section of the Help for more information. Variational Technology This property is available when the Solution Method is set to Full. When this property is set to No, the harmonic response uses the Full method, in which a direct solution of the simultaneous equations of motion are solved for each excitation frequency, i.e., frequency steps defined in the Solution Intervals. When this property is set to Yes, it uses Variational Technology to evaluate harmonic response for each excitation frequency based on one direct solution. This property is set to Program Controlled by default allowing the application to select the best solution method based on the model. For more technical information about Variational Technology, see the Harmonic Analysis Variational Technology Method section of the Mechanical APDL Theory Reference. This option is an alternate Solution Method that is based on the harmonic sweep algorithm of the Full method. For additional information, see the HROPT command in the MAPDL Command Reference. If a Command object is used with the MSUP method, object content is sent twice; one for the modal solution and another for the harmonic solution. For that reason, harmonic responses are double if a load command is defined in the object, e.g., F command.

Preparing the Analysis Create Analysis System

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Linear Dynamic Analysis Types Basic general information about this topic … for this analysis type: From the Toolbox, drag the Harmonic Response template to the Project Schematic. Define Engineering Data Basic general information about this topic … for this analysis type: Both Young’s modulus (or stiffness in some form) and density (or mass in some form) must be defined. Material properties must be linear but can be isotropic or orthotropic, and constant or temperature-dependent. Nonlinear properties, if any, are ignored. Attach Geometry Basic general information about this topic … for this analysis type: There are no specific considerations for a harmonic analysis. Define Part Behavior Basic general information about this topic … for this analysis type: You can define a Point Mass for this analysis type. Define Connections Basic general information about this topic … for this analysis type: Any nonlinear contact such as Frictional contact retains the initial status throughout the harmonic analysis. The stiffness contribution from the contact is based on the initial status and never changes. The stiffness as well as damping of springs is taken into account in a Full method of harmonic analysis. In a Mode Superposition harmonic analysis, the damping from springs is ignored. Apply Mesh Controls/Preview Mesh Basic general information about this topic … for this analysis type: There are no specific considerations for harmonic analysis.

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Analysis Types Establish Analysis Settings Basic general information about this topic … for this analysis type: For a Harmonic Analysis, the basic controls are: • Options — Here you specify the frequency range and the number of solution points at which the harmonic analysis will be carried out as well as the solution method to use and the relevant controls. Two solution methods are available to perform harmonic analysis: the Mode Superposition method, the Direct Integration (Full) method, and the Variational Technology method. – Mode Superposition (MSUP) method: In this method a modal analysis is first performed to compute the natural frequencies and mode shapes. Then the mode superposition solution is carried out where these mode shapes are combined to arrive at a solution. This is the default method, and generally provides results faster than the Full method or the Variational Technology method. The Mode Superposition method cannot be used if you need to apply imposed (nonzero) displacements. This method also allows solutions to be clustered about the structure’s natural frequencies. This results in a smoother, more accurate tracing of the response curve. The default method of equally spaced frequency points can result in missing the peak values. Without Cluster Option:

With Cluster Option:

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Linear Dynamic Analysis Types

The Store Results At All Frequencies option, when set to No, requests that only minimal data be retained to supply just the harmonic results requested at the time of solution. The availability of the results is therefore not determined by the settings in the Output Controls.

Note With this option set to No, the addition of new frequency or phase responses to a solved environment requires a new solution. Adding a new contour result of any type (stress or strain) or a new probe result of any type (reaction force or reaction moment) for the first time on a solved environment requires you to solve, but adding additional contour results or probe results of the same type does not share this requirement; data from the closest available frequency is displayed (the reported frequency is noted on each result).

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Analysis Types New and/or additional displacement contour results as well as bearing probe results do not share this requirement. These results types are basic data and are available by default. The values of frequency, type of contour results (stress or strain) and type of probe results (reaction force, reaction moment, or bearing) at the moment of the solution determine the contents of the result file and the subsequent availability of data. Planning these choices can significantly reduce the need to re-solve an analysis.

Caution Use caution when adding result objects to a solved analysis. Adding a new result invalidates the solution and requires the system to be re-solved, even if you were to add and then delete a result object.

– Full method: Calculates all displacements and stresses in a single pass. Its main disadvantages are: → It is more “expensive” in CPU time than the Mode Superposition method. → It does not allow clustered results, but rather requires the results to be evenly spaced within the specified frequency range. • Damping Controls allow you to specify damping for the structure in the Harmonic analysis. Controls include: Constant Damping Ratio, Stiffness Coefficient (beta damping), and a Mass Coefficient (alpha damping). They can also be applied as Material Damping using the Engineering Data tab. Element Damping: You can also apply damping through spring-damper elements. The damping from these elements is used only in a Full method harmonic analysis.

Note If multiple damping specifications are made the effect is cumulative.

• Analysis Data Management settings enable you to save solution files from the harmonic analysis. The default behavior is to only keep the files required for postprocessing. You can use these controls to keep all files created during solution or to create and save the Mechanical APDL application database (db file). Define Initial Conditions Basic general information about this topic For a Pre-Stressed Full Harmonic analysis, the preloaded status of a structure is used as a starting point for the Harmonic analysis. That is, the static structural analysis serves as

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Linear Dynamic Analysis Types an Initial Condition for the Full Harmonic analysis. See the Applying Pre-Stress Effects section of the Help for more information.

Note In the Pre-Stressed MSUP Harmonic Analysis, the prestress effects are applied using a Modal analysis. … for this analysis type: Currently, the initial conditions Initial Displacement and Initial Velocity are not supported for Harmonic analyses. Apply Loads and Supports Basic general information about this topic … for this analysis type: A Harmonic Response Analysis supports the following boundary conditions for a Solution Method setting of either Full or MSUP: Inertial Acceleration (Phase Angle not supported.) Loads • Pressure • Pipe Pressure (line bodies only) — Not supported for MSUP Solution Method. • Force (applied to a face, edge, or vertex) • Moment • Remote Force • Bearing Load (Phase Angle not supported.) • Line Pressure • Given a specified Displacement Supports Any type of linear Support can be used in harmonic analyses.

Note The Compression Only support is nonlinear but should not be utilized even though it behaves linearly in harmonic analyses. Conditions Constraint Equation Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types Direct FE (Node-based Named Selection scoping only) • Nodal Orientation (Phase Angle not supported.) • Nodal Force • Nodal Displacement

Note Support for boundary conditions varies for a Harmonic Response analysis that is linked to either a Static-Structural or Modal analysis. See the Harmonic Response Analysis Using Linked Modal Analysis System (p. 189) or the Harmonic Analysis Using Pre-Stressed Structural System sections of the Help for specific boundary condition support information. In a Harmonic Analysis, boundary condition application has the following requirements: • You can apply multiple boundary conditions to the same face. • All boundary conditions must be sinusoidally time-varying. • Transient effects are not calculated. • All boundary conditions must have the same frequency. • Boundary conditions supported with the Phase Angle property allow you to specify a phase shift that defines how the loads can be out of phase with one another. As illustrated in the example Phase Response below, the pressure and force are 45o out of phase. You can specify the preferred unit for phase angle (in fact all angular inputs) to be degrees or radians using the Units toolbar.

• An example of a Bearing Load acting on a cylinder is illustrated below. The Bearing Load, acts on one side of the cylinder. In a harmonic analysis, the expected behavior is that the other side of the cylinder is loaded in reverse; however, that is not the case. The applied load simply reverses sign (becomes tension). As a result, you should avoid the use of Bearing Loads in this analysis type.

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Linear Dynamic Analysis Types

Solve Basic general information about this topic … for this analysis type: Solution Information continuously updates any listing output from the solver and provides valuable information on the behavior of the structure during the analysis. Review Results Basic general information about this topic … for this analysis type: Two types of results can be requested for harmonic analyses: • Contour plots include stress, elastic strain, and deformation, and are basically the same as those for other analyses. For these results, you must specify an excitation frequency and a phase. The Sweeping Phase property in the details view for the result is the specified phase, in time domain, and it is equivalent to the product of the excitation frequency and time. Because Frequency is already specified in the Details view, the Sweeping Phase variation produces the contour results variation over time. The Sweeping Phase property defines the parameter used for animating the results over time. You can then see the total response of the structure at a given point in time, as shown below.

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Analysis Types Since each node may have different phase angles from one another, the complex response can also be animated to see the time-dependent motion. • Frequency Response and Phase Response charts which give data at a particular location over an excitation frequency range and a phase period (the duration of the Phase Response results, respectively). Graphs can be either Frequency Response graphs that display how the response varies with frequency or Phase Response plots that show how much a response lags behind the applied loads over a phase period.

Note You can create a contour result from a Frequency Response result type in a Harmonic Analysis using the Create Contour Result feature. This feature creates a new result object in the tree with the same Type, Orientation, and Frequency as the Frequency Response result type. However, the Phase Angle of the contour result has the same magnitude as the frequency result type but an opposite sign (negative or positive). The sign of the phase angle in the contour result is reversed so that the response amplitude of the frequency response plot for that frequency and phase angle matches with the contour results.

Harmonic Response (Full) Analysis Using Pre-Stressed Structural System Preparing the Analysis Create Analysis System Basic general information about this topic … for this analysis type: Because this analysis is linked to (and based on) structural responses, a Static-Structural analysis is a prerequisite. This setup allows the two analysis systems to share resources, such as engineering data, geometry, and the boundary condition type definitions that are defined the in the structural analysis. From the Toolbox, drag a Static-Structural template to the Project Schematic. Then, drag a Harmonic Response template directly onto the Solution cell of the Structural template. Establish Analysis Settings Basic general information about this topic … for this analysis type: The Analysis Settings associated with this type of analysis are outlined below. Options Group — See the Harmonic Analysis Options Group section for a complete listing of the Details properties for a Harmonic Response analysis. For a Harmonic Response Analysis using a linked a structural analysis system, only the Full Solution Method option is applicable, and therefore it is read-only.

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Linear Dynamic Analysis Types Output Controls — You can request Stress, Strain, Nodal Force, and Reaction results to be calculated. Define Initial Conditions Basic general information about this topic … for this analysis type: The Initial Conditions (Pre-Stress) object of the Harmonic Response analysis must point to the linked Static Structural analysis. See the Applying Pre-Stress Effects for Implicit Analysis Help section for more information about using a pre-stressed environment. Apply Loads and Supports Basic general information about this topic … for this analysis type: The following loads are allowed for linked Harmonic Response (Full) analysis: • Inertial: Acceleration (Phase Angle not supported.) • Direct FE (Node-based Named Selection scoping only) – Nodal Force – Nodal Pressure (Phase Angle not supported.) – Nodal Displacement — At least one non-zero Component is required for the boundary condition to be fully defined.

Note Any other boundary conditions must be defined in the prerequisite (parent) Structural Analysis, such as Support Type boundary conditions.

Harmonic Response Analysis Using Linked Modal Analysis System Preparing the Analysis Create Analysis System Basic general information about this topic … for this analysis type: Because this analysis is linked to (or based on) modal responses, a Modal analysis is a prerequisite. This setup allows the two analysis systems to share resources such as en-

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Analysis Types gineering data, geometry and boundary condition type definitions made in modal analysis.

Note The Mode Superposition harmonic is allowed to be linked to a pre-stressed modal analysis. From the Toolbox, drag a Modal template to the Project Schematic. Then, drag a Harmonic Response template directly onto the Solution cell of the Modal template. Establish Analysis Settings Basic general information about this topic … for this analysis type: Options — See the Harmonic Analysis Options Group section for a complete listing of the Details properties for a Harmonic analysis. Please note that for a Harmonic Analysis Using Linked Modal Analysis System, only the Mode Superposition option is applicable, and therefore is read-only. In addition, you can turn the Include Residual Vectors property On to execute the RESVEC command and calculate residual vectors. Also, Mode Frequency Range is not applicable because available modes are defined in the linked Modal system. Output Controls — You can request Stress, Strain, Nodal Force, and Reaction results to be calculated. For better performance, you can also choose to have these results expanded from Harmonic or Modal solutions. To expand reaction forces in the modal solution, set the Nodal Force property to Yes or Constrained Nodes. Define Initial Conditions Basic general information about this topic … for this analysis type: The Harmonic analysis must point to a Modal analysis in the Modal (Initial Conditions) object. This object also indicates whether the upstream Modal analysis is pre-stressed. If it is a pre-stress analysis, the name of the pre-stress analysis system is displayed in the Pre-Stress Environment field, otherwise the field indicates None. The Modal Analysis must extract enough modes to cover the frequency range. A conservative rule of thumb is to extract enough modes to cover 1.5 times the maximum frequency in the excitation.

Note Command objects can be inserted into Initial Conditions object to execute a restart of the solution process for the Modal Analysis. Apply Loads and Supports Basic general information about this topic

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Linear Dynamic Analysis Types … for this analysis type: The following loads are allowed for the linked analysis: Inertial Acceleration (Phase Angle not supported.) Loads • Pressure • Pipe Pressure (line bodies only) • Force (applied to a face, edge, or vertex) • Moment • Remote Force • Bearing Load (Phase Angle not supported.) • Line Pressure • Given a specified Displacement

Support Limitations Note the following analysis requirements. • Remote Force is not supported for vertex scoping. • Moment is not supported for vertex scoping on 3D solid bodies because a beam entity is created for the load application. • During a linked MSUP Transient analysis, if a Remote Force or Moment is specified with the Behavior property set to Deformable, the boundary conditions cannot be scoped to the edges of line bodies such that all of their nodes in combination are collinear.

Caution Mode Superposition (MSUP) Harmonic Analysis When you have a Modal Analysis that is pre-stressed by a Static Structural Analysis, you cannot include the following boundary conditions with non-zero magnitude values in the Static Structural Analysis. • Displacement • Remote Displacement • Pretension Bolt Load (Pre-adjustment)

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Linear Buckling Analysis Introduction Linear buckling (also called as Eigenvalue buckling) analysis predicts the theoretical buckling strength of an ideal elastic structure. This method corresponds to the textbook approach to elastic buckling analysis: for instance, an eigenvalue buckling analysis of a column will match the classical Euler solution. However, imperfections and nonlinearities prevent most real-world structures from achieving their theoretical elastic buckling strength. Thus, linear buckling analysis often yields quick but non-conservative results. A linear buckling analysis can be performed using the ANSYS or Samcef solver. Differences between the solvers are noted in the sections below. F

F

Snap-through buckling

Bifurcation point Limit load (from nonlinear buckling)

u (a)

u (b)

(a) Nonlinear load-deflection curve, (b) Linear (Eigenvalue) buckling curve A more accurate approach to predicting instability is to perform a nonlinear buckling analysis. This involves a static structural analysis with large deflection effects turned on. A gradually increasing load is applied in this analysis to seek the load level at which your structure becomes unstable. Using the nonlinear technique, your model can include features such as initial imperfections, plastic behavior, gaps, and large-deflection response. In addition, using deflection-controlled loading, you can even track the post-buckled performance of your structure (which can be useful in cases where the structure buckles into a stable configuration, such as «snap-through» buckling of a shallow dome).

Points to Remember • A Linear Buckling Analysis must be linked to (preceded by) a Static Structural Analysis. • The results calculated by the linear buckling analysis are buckling load factors that scale the loads applied in the static structural analysis. Thus for example if you applied a 10 N compressive load on a structure in the static analysis and if the linear buckling analysis calculates a load factor of 1500, then the predicted buckling load is 1500×10 = 15000 N. Because of this it is typical to apply unit loads in the static analysis that precedes the buckling analysis. • The buckling load factor is to be applied to all the loads used in the static analysis. • A structure can have infinitely many buckling load factors. Each load factor is associated with a different instability pattern. Typically the lowest load factor is of interest.

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Linear Dynamic Analysis Types • Note that the load factors represent scaling factors for all loads. If certain loads are constant (for example, self-weight gravity loads) while other loads are variable (for example, externally applied loads), you need to take special steps to ensure accurate results. One strategy that you can use to achieve this end is to iterate on the linear buckling solution, adjusting the variable loads until the load factor becomes 1.0 (or nearly 1.0, within some convergence tolerance). Consider, for example, a pole having a self-weight W0, which supports an externally-applied load, A. To determine the limiting value of A in a linear buckling analysis, you could solve repetitively, using different values of A, until by iteration you find a load factor acceptably close to 1.0.

• You can apply a nonzero constraint in the static analysis. The load factors calculated in the buckling analysis should also be applied to these nonzero constraint values. However, the buckling mode shape associated with this load will show the constraint to have zero value. • Buckling mode shape displays are helpful in understanding how a part or an assembly deforms when buckling, but do not represent actual displacements.

Preparing the Analysis Create Analysis System Basic general information about this topic … for this analysis type: From the Toolbox, drag a Linear Buckling or Linear Buckling (Samcef) template to the Project Schematic. Define Engineering Data Basic general information about this topic … for this analysis type: • Young’s modulus (or stiffness in some form) must be defined. • Material properties can be linear, isotropic or orthotropic, and constant or temperaturedependent. • Nonlinear properties, if any, are ignored. Attach Geometry Basic general information about this topic Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types … for this analysis type: There are no specific considerations for a linear buckling analysis. Define Part Behavior Basic general information about this topic … for this analysis type: There are no specific considerations for a linear buckling analysis. Define Connections Basic general information about this topic … for this analysis type: When the Formulation property is set to MPC, the Bonded and No Separation options of the Type property are valid linear contact behaviors for linear buckling analyses. Springs are taken into account if they are present in the static analysis. Apply Mesh Controls/Preview Mesh Basic general information about this topic … for this analysis type: There are no considerations specifically for a linear buckling analysis. Establish Analysis Settings Basic general information about this topic … for this analysis type: For linear buckling analysis the basic controls are: Options for Analyses (p. 648): Use the Number of Modes property to specify the number of buckling load factors and corresponding buckling mode shapes of interest. Typically the first (lowest) buckling load factor is of interest. Solver Controls: The default option, Program Controlled, allows the application to select the appropriate solver type. Options include Program Controlled, Direct, and Subspace. By default, the Program Controlled option uses the Direct solver. Output Controls (p. 658): By default only buckling load factors and corresponding buckling mode shapes are calculated. You can request Stress and Strain results to be calculated but note that “stress” results only show the relative distribution of stress in the structure and are not real stress values. In Analysis Data Management (p. 664), users can set the save the Mechanical APDL application database and delete unneeded file settings.

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Linear Dynamic Analysis Types Output controls are exposed for the ANSYS solver only. Define Initial Conditions Basic general information about this topic … for this analysis type: You must point to a static structural analysis of the same model in the initial condition environment. • Linear buckling analysis must be preceded by a static structural analysis. The solver for the static structural analysis (ANSYS or Samcef ) must match the solver for the linear buckling analysis. • If the static structural analysis has multiple result sets, the value from any restart point available in the static structural analysis can be used as the basis for the linear buckling analysis. See Restarts from Multiple Result Sets (p. 139) in the Applying Pre-Stress Effects Help section for more information. • The results calculated by the linear buckling analysis are buckling load factors that scale the loads applied in the static structural analysis. Thus for example if you applied a 10 N compressive load on a structure in the static analysis and if the linear buckling analysis calculates a load factor of 1500, then the predicted buckling load is 1500×10 = 15000 N. Because of this it is typical to apply unit loads in the static analysis that precedes the buckling analysis. • The buckling load factor is to be applied to all the loads used in the static analysis. Apply Loads and Supports Basic general information about this topic … for this analysis type: No loads are allowed in the linear buckling analysis. The supports as well as the stress state from the static structural analysis are used in the linear buckling analysis. See the Applying Pre-Stress Effects for Implicit Analysis Help Section for more information about using a pre-stressed environment. Solve Basic general information about this topic … for this analysis type: Solution Information continuously updates any listing output from the solver and provides valuable information on the behavior of the structure during the analysis. Review Results Basic general information about this topic … for this analysis type: Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types You can view the buckling mode shape associated with a particular load factor by displaying a contour plot or by animating the deformed mode shape. The contours represent relative displacement of the part. Buckling mode shape displays are helpful in understanding how a part or an assembly deforms when buckling, but do not represent actual displacements. “Stresses” from a Linear Buckling analysis do not represent actual stresses in the structure, but give you an idea of the relative stress distributions for each mode. Stress and Strain results are available only if requested before solution using Output Controls (p. 658).

Modal Analysis Introduction A modal analysis determines the vibration characteristics (natural frequencies and mode shapes) of a structure or a machine component. It can also serve as a starting point for another, more detailed, dynamic analysis, such as a transient dynamic analysis, a harmonic analysis, or a spectrum analysis. The natural frequencies and mode shapes are important parameters in the design of a structure for dynamic loading conditions. You can also perform a modal analysis on a prestressed structure, such as a spinning turbine blade. If there is damping in the structure or machine component, the system becomes a damped modal analysis. For a damped modal system, the natural frequencies and mode shapes become complex. For a rotating structure or machine component, the gyroscopic effects resulting from rotational velocities are introduced into the modal system. These effects change the system’s damping. The damping can also be changed when a Bearing is present, which is a common support used for rotating structure or machine component. The evolution of the natural frequencies with the rotational velocity can be studied with the aid of Campbell Diagram Chart Results. A modal analysis can be performed using the ANSYS or Samcef solver. Any differences are noted in the sections below. Rotordynamic analysis is not available with the Samcef solver.

Points to Remember • The Rotational Velocity load is not available in Modal Analysis when the analysis is linked to a Static structural analysis. • Prestressed modal analysis requires performing a static structural analysis first. In the modal analysis you can use the Initial Condition object to point to the Static Structural analysis to include prestress effects.

Preparing the Analysis Create Analysis System Basic general information about this topic … for this analysis type: From the Toolbox, drag a Modal or a Modal (Samcef) template to the Project Schematic. Define Engineering Data 196

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Linear Dynamic Analysis Types Basic general information about this topic … for this analysis type: Due to the nature of modal analyses any nonlinearities in material behavior are ignored. Optionally, orthotropic and temperature-dependent material properties may be used. The critical requirement is to define stiffness as well as mass in some form. Stiffness may be specified using isotropic and orthotropic elastic material models (for example, Young’s modulus and Poisson’s ratio), using hyperelastic material models (they are linearized to an equivalent combination of initial bulk and shear moduli), or using spring constants, for example. Mass may derive from material density or from remote masses.

Note Hyperelastic materials are supported for pre-stress modal analyses. They are not supported for standalone modal analyses. Attach Geometry Basic general information about this topic … for this analysis type: When 2D geometry is used, Generalized Plane Strain is not supported for the Samcef solver. When performing a Rotordynamic Analysis, the rotors can be easily generated using the Import Shaft Geometry feature of ANSYS DesignModeler. The feature uses a text file to generate a collection of line bodies with circular or circular tube cross sections. Define Part Behavior Basic general information about this topic … for this analysis type: You can define a Point Mass for this analysis type. Define Connections Basic general information about this topic … for this analysis type: • Joints are allowed in a modal analysis. They restrain degrees of freedom as defined by the joint definition. • The stiffness of any spring is taken into account and if specified, damping is also considered. • For the Samcef solver, only contacts, springs, and beams are supported. Joints are not supported. Apply Mesh Controls/Preview Mesh Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types Basic general information about this topic … for this analysis type: There are no special considerations for this analysis type. Establish Analysis Settings Basic general information about this topic … for this analysis type: Number of Modes: You need to specify the number of frequencies of interest. The default is to extract the first 6 natural frequencies. The number of frequencies can be specified in two ways: 1. The first N frequencies (N > 0), or 2. The first N frequencies in a selected range of frequencies. Solver Controls (p. 639): Two settings are available in this control – Damped and Solver Type. For Damped, you can specify if the modal system is undamped or damped. Depending on the selection made for Damped, different solver options are provided accordingly. Damped by default, it is set No and assumes the modal system is an undamped system. Solver Type (p. 640): Typically you should let the program choose the type of solver appropriate for your model in both undamped and damped modal systems.

Note • If a solver type of Unsymmetric, Full Damped or Reduced Damped is selected, the modal system cannot be followed by a Transient Structural, Harmonic Response, Random Vibration, or Response Spectrum system. However, for a MSUP Harmonic Analysis and a MSUP Transient Analysis, you can use the Reduced Damped solver with the Store Complex Solution property set to No. In this case, regular (non-complex) mode shapes are calculated and are used for mode superposition. Although complex frequencies are used for mode superposition, regular (non-complex) frequencies are reported in tabular data. In the presence of damping , the Reduced Damped solver with Store Complex Solution set to No is not equivalent to the Undamped solver. • If an undamped Modal analysis has a pre-stressed environment from a Static Structural Analysis with the Newton-Raphson Option set to Unsymmetric, the Program Controlled option selects Unsymmetric as the Solver Type setting (the MAPDL command MODOPT,UNSYM is issued).

Store Complex Solution: This control is only available when a damped solver type of Reduced Damped is selected. This control allows you to solve and store a damped modal system as an undamped modal system. By default, it is set to Yes.

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Linear Dynamic Analysis Types Cyclic Controls: When running a cyclic symmetry analysis, set the Harmonic Index Range to Program Controlled to solve for all harmonic indices, or to Manual to solve for a specific range of harmonic indices. Output Controls (p. 658): By default only mode shapes are calculated. You can request Stress and Strain results to be calculated but note that “stress” results only show the relative distribution of stress in the structure and are not real stress values. You can also choose whether or not to have these results stored for faster result calculations in linked systems. Damping Controls (p. 653): Two damping types, Stiffness Coefficient and Mass Coefficient, are available to set up a damped modal system. Stiffness Coefficient can be defined in two ways, either by Direct Input or by Damping Vs Frequency. Rotordynamics Controls (p. 666): Specify Rotordynamics Controls as needed when setting up a Rotordynamic Analysis. Analysis Data Management (p. 664) (applicable to Modal systems only) settings enable you to save specific solution files from the Modal analysis for use in other analyses. You can set the Future Analysis field to MSUP Analyses if you intend to use the modal results in a subsequent Transient Structural, Harmonic Response, Random Vibration (PSD), or Response Spectrum (RS) analysis. If you link a Modal system to another analysis type in advance, the Future Analysis property defaults to the setting, MSUP Analyses. When a PSD analysis is linked to a modal analysis, additional solver files must be saved to achieve the PSD solution. If the files were not saved, then the modal analysis has to be solved again and the files saved. Solver Type, Damping Controls, and Rotordynamic Controls are not available to the Samcef solver.

Note Solver Type, Scratch Solver Files, Save ANSYS db, Solver Units, and Solver Unit System are applicable to Modal systems only. Define Initial Conditions Basic general information about this topic … for this analysis type: You can point to a Static Structural analysis in the Initial Condition environment field if you want to include prestress effects. A typical example is the large tensile stress induced in a turbine blade under centrifugal load that can be captured by a static structural analysis. This causes significant stiffening of the blade. Including this pre-stress effect will result in much higher, realistic natural frequencies in a modal analysis. If the Modal analysis is linked to a Static Structural analysis for initial conditions and the parent static structural analysis has multiple result sets (multiple restart points at load steps/sub steps), you can start the Modal analysis from any restart point available in the Static Structural analysis. By default, the values from the last solve point are used as the

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Analysis Types basis for the modal analysis. See Restarts from Multiple Result Sets (p. 139) in the Applying Pre-Stress Effects for Implicit Analysis Help section for more information.

Note When you perform a prestressed Modal analysis, the support conditions from the static analysis are used in the Modal analysis. You cannot apply any new supports in the Modal analysis portion of a prestressed modal analysis. See the Pressure Load Stiffness topic in the Applying Pre-Stress Effects for Implicit Analysis Help Section for more information about using a pre-stressed environment. Apply Loads and Supports Basic general information about this topic … for this analysis type: Only Rotational Velocity load is allowed in a stand-alone modal analysis. All structural supports can be applied except the Non-zero Displacement, Remote Displacement, and the Velocity boundary condition. Due to their nonlinear nature, compression only supports are not recommended in a modal analysis. Use of compression only supports may result in extraneous or missed natural frequencies. For the Samcef solver, the following supports are not available: Compression Only Support, Elastic Support. When using line bodies, the following Pipe Pressure and Pipe Temperature loads are not available to the Samcef solver. Additionally, the Pipe Idealization object is also unavailable for the Samcef solver.

Note Pre-stressed Modal Analysis: • In a pre-stressed modal analysis any structural supports used in the static analysis persist. Therefore, you are not allowed to add new supports in the pre-stressed modal analysis. • Rotational Velocity is not available for Modal Analysis system in a prestressed modal analysis.

Solve Basic general information about this topic … for this analysis type: Solution Information continuously updates any listing output from the solver and provides valuable information on the behavior of the structure during the analysis. Review Results

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Linear Dynamic Analysis Types Basic general information about this topic … for this analysis type: Highlight the Solution object in the tree to view a bar chart of the frequencies obtained in the modal analysis. A tabular data grid is also displayed that shows the list of frequencies, stabilities, modal damping ratios and logarithm decrements of each mode.

Note In a Modal Analysis (and other eigenvalue-based analyses such as buckling), the solution consists of a deformed shape scaled by an arbitrary factor. The actual magnitudes of the deformations and any derived quantities, such as strains and stresses, are therefore meaningless. Only the relative values of such quantities throughout the model should be considered meaningful. The arbitrary scaling factor is numerically sensitive to slight perturbations in the analysis; choosing a different unit system, for example, can cause a significantly different scaling factor to be calculated. For an undamped modal analysis, only frequencies are available in the Tabular Data window. For a damped modal analysis, real and imaginary parts of the eigenvalues of each mode are listed as Stability and Damped Frequency, respectively, in the Tabular Data window. If the real/stability value is negative, the eigenmode is considered to be stable. For the damped modal analysis, Modal Damping Ratio and Logarithmic Decrement are also included in the Tabular Data window. Like the stability value, these values are an indicator of eigenmode stability commonly used in rotordynamics. If Campbell Diagram is set to On, a Campbell diagram chart result is available for insert under Solution. A Campbell diagram chart result conveys information as to how damped frequencies and stabilities of a rotating structural component evolve/change in response to increased rotational velocities. More detailed information about the result can be found in Campbell Diagram Chart Results (p. 949). The Campbell Diagram function is not available to the Samcef solver.

Note The Campbell diagram result chart is only appropriate for a rotating structural component that is axis-symmetrical. It is supported for all body types: solid, shell, and line bodies, but limited to single spool systems. For a single spool system, all bodies in the modal system are subjected to one and only single rotational velocity. The contour and probe results are post-processed using set number, instead of mode number. The total set number is equal to number of modes requested multiplied by number of rotational velocity solve points. You can use the Set, Solve Point and Mode columns in the table to navigate between the set number and mode, and rotational velocity solve point and mode. You can choose to review the mode shapes corresponding to any of these natural frequencies by selecting the frequency from the bar chart or tabular data and using the

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Analysis Types context sensitive menu (right mouse click) to choose Create Mode Shape Results. You can also view a range of mode shapes. “Stresses” from a Modal analysis do not represent actual stresses in the structure, but they give you an idea of the relative stress distributions for each mode. Stress and Strain results are available only if requested before solution using Output Controls. You can view the mode shape associated with a particular frequency as a contour plot. You can also animate the deformed shape including, for a damped analysis, the option to allow or ignore the time decay animation for complex modes. The contours represent relative displacement of the part as it vibrates. For complex modes, the Phase Angle associated with a particular frequency represents the specified angle in time domain and is equivalent to the product of frequency and time. Since the frequency is already specified in the results details view for a specific mode, the phase angle variation produces the relative variation of contour results over time. When running a cyclic symmetry analysis, additional result object settings in the Details view are available, as well as enhanced animations and graph displays. See Cyclic Symmetry in a Modal Analysis for more information.

Note The use of construction geometry is not supported for the postprocessing of cyclic symmetry results.

Random Vibration Analysis Introduction This analysis enables you to determine the response of structures to vibration loads that are random in nature. An example would be the response of a sensitive electronic component mounted in a car subjected to the vibration from the engine, pavement roughness, and acoustic pressure. Loads such as the acceleration caused by the pavement roughness are not deterministic, that is, the time history of the load is unique every time the car runs over the same stretch of road. Hence it is not possible to predict precisely the value of the load at a point in its time history. Such load histories, however, can be characterized statistically (mean, root mean square, standard deviation). Also random loads are non-periodic and contain a multitude of frequencies. The frequency content of the time history (spectrum) is captured along with the statistics and used as the load in the random vibration analysis. This spectrum, for historical reasons, is called Power Spectral Density or PSD. In a random vibration analysis since the input excitations are statistical in nature, so are the output responses such as displacements, stresses, and so on. Typical applications include aerospace and electronic packaging components subject to engine vibration, turbulence and acoustic pressures, tall buildings under wind load, structures subject to earthquakes, and ocean wave loading on offshore structures.

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Linear Dynamic Analysis Types

Points to Remember • The excitation is applied in the form of Power Spectral Density (PSD). The PSD is a table of spectral values vs. frequency that captures the frequency content. The PSD captures the frequency and mean square amplitude content of the load’s time history. • The square root of the area under a PSD curve represents the root mean square (rms) value of the excitation. The unit of the spectral value of acceleration, for example, is G2/Hertz. • The input excitation is expected to be stationary (the average mean square value does not change with time) with a zero mean. • This analysis is based on the mode superposition method. Hence a modal analysis that extracts the natural frequencies and mode shapes is a prerequisite. • This feature covers one type of PSD excitation only- base excitation. • The base excitation could be an acceleration PSD (either in acceleration2 units or in G2 units), velocity PSD or displacement PSD. • The base excitation is applied in the specified direction to all entities that have a Fixed Support boundary condition. Other support points in a structure such as Frictionless Surface are not excited by the PSD. • Multiple uncorrelated PSDs can be applied. This is useful if different, simultaneous excitations occur in different directions. • If stress/strain results are of interest from the random vibration analysis then you will need to request stress/strain calculations in the modal analysis itself. Only displacement results are available by default. • Postprocessing: – The results output by the solver are one sigma or one standard deviation values (with zero mean value). These results follow a Gaussian distribution. The interpretation is that 68.3% of the time the response will be less than the standard deviation value. – You can scale the result by 2 times to get the 2 sigma values. The response will be less than the 2 sigma values 95.45% of the time and 3 sigma values 99.73% of the time. – The Coordinate System setting for result objects is, by default, set to Solution Coordinate System and cannot be changed because the results only have meaning when viewed in the solution coordinate system. – Since the directional results from the solver are statistical in nature they cannot be combined in the usual way. For example the X, Y, and Z displacements cannot be combined to get the magnitude of the total displacement. The same holds true for other derived quantities such as principal stresses. – A special algorithm by Segalman-Fulcher is used to compute a meaningful value for equivalent stress.

Preparing the Analysis Create Analysis System Basic general information about this topic

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Analysis Types … for this analysis type: Because a random vibration analysis is based on modal responses, a modal analysis is a required prerequisite. The requirement then is for two analysis systems, a modal analysis system and a random vibration analysis system that share resources, geometry, and model data. From the Toolbox, drag a Modal template to the Project Schematic. Then, drag a Random Vibration template directly onto the Modal template. Define Engineering Data Basic general information about this topic … for this analysis type: Both Young’s modulus (or stiffness in some form) and density (or mass in some form) must be defined in the modal analysis. Material properties must be linear but can be isotropic or orthotropic, and constant or temperature-dependent. Nonlinear properties, if any, are ignored. Attach Geometry Basic general information about this topic … for this analysis type: There are no specific considerations for a random vibration analysis. Define Part Behavior Basic general information about this topic … for this analysis type: There are no specific considerations for a random vibration analysis. Define Connections Basic general information about this topic … for this analysis type: Only linear behavior is valid in a random vibration analysis. Nonlinear elements, if any, are treated as linear. If you include contact elements, for example, their stiffnesses are calculated based on their initial status and are never changed. Only the stiffness of springs are taken into account in a random vibration analysis. Apply Mesh Controls/Preview Mesh Basic general information about this topic … for this analysis type: 204

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Linear Dynamic Analysis Types There are no specific considerations for a random vibration analysis. Establish Analysis Settings Basic general information about this topic … for this analysis type: For a random vibration analysis the basic controls are: Options for Analyses (p. 648). You can specify the number of modes to use from the modal analysis. A conservative rule of thumb is to include modes that cover 1.5 times the maximum frequency in the PSD excitation table. You can also exclude insignificant modes by setting a mode significance level between 0 (all modes selected) and 1 (no modes selected). Output Controls. By default, Displacement, Velocity, and Acceleration responses are calculated. To exclude Velocity and/or Acceleration responses, set their respective Output Controls to No. By default, modal results are removed from result file to reduce its size. To keep modal results, set the Keep Modal Results property to Yes. Damping Controls (p. 653) allow you to specify damping for the structure in the Random Vibration analysis. Controls include: Constant Damping, Constant Damping Ratio, Stiffness Coefficient (beta damping), and a Mass Coefficient (alpha damping). They can also be applied as Material Damping using the Engineering Data tab. A non-zero damping is required. The Constant Damping Ratio has a default setting of 0.01. This value can be modified by setting the Constant Damping property to Manual. Analysis Data Management (p. 664) settings enable you to save solution files from the Random Vibration analysis. The default behavior is to only keep the files required for postprocessing. You can use these controls to keep all files created during solution or to create and save a the Mechanical APDL application database (db file).

Note The Inertia Relief option (under Analysis Settings) for an upstream static structural analysis is not supported in a random vibration analysis. Define Initial Conditions Basic general information about this topic … for this analysis type: You must point to a modal analysis in the Initial Condition environment field. The modal analysis must extract enough modes to cover the PSD frequency range. A conservative rule of thumb is to extract enough modes to cover 1.5 times the maximum frequency in the PSD excitation. When a PSD analysis is linked to a modal analysis, additional solver files must be saved to achieve the PSD solution. (See Analysis Data Management (p. 664).) If the files were not saved, then the modal analysis has to be solved again and the files saved. Apply Loads and Supports Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types Basic general information about this topic … for this analysis type: • Any Support Type boundary condition must be defined in the prerequisite Modal Analysis. • The only applicable load is a PSD Base Excitation of spectral value vs. frequency. • Remote displacement cannot coexist with other boundary condition types (for example, fixed support or displacement) on the same location for excitation. The remote displacement will be ignored due to conflict with other boundary conditions. • Four types of base excitation are supported: PSD Acceleration, PSD G Acceleration, PSD Velocity, and PSD Displacement. • Each PSD base excitation should be given a direction in the nodal coordinate of the excitation points. • Multiple PSD excitations (uncorrelated) can be applied. Typical usage is to apply 3 different PSDs in the X, Y, and Z directions. Correlation between PSD excitations is not supported. Solve Basic general information about this topic … for this analysis type: Solution Information continuously updates any listing output from the solver and provides valuable information on the behavior of the structure during the analysis. In addition to solution progress you will also find the participation factors for each PSD excitation. The solver output also has a list of the relative importance of each mode in the modal covariance matrix listing.

Note When using a random vibration system database from a version prior to the most current version of Mechanical, it is possible to encounter incompatibility of the files file.mode and/or file.esav, created by the modal system. This incompatibility can cause the random vibration system’s solution to fail. In the event you experience this issue, use the Clear Generated Data feature and resolve the modal system. Review Results Basic general information about this topic … for this analysis type: • If stress/strain results are of interest from the random vibration analysis then you will need to request stress/strain calculations in the modal analysis itself. You can use the Output Controls under Analysis Settings in the modal analysis for this purpose. Only displacement results are available by default.

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Linear Dynamic Analysis Types • Linking a Random Vibration analysis system to a fully solved Modal analysis may result in zero equivalent stress. To evaluate correct equivalent stress in this situation, you need to re-solve the Modal analysis. • Applicable results are Directional (X/Y/Z) Displacement/Velocity/Acceleration, normal and shear stresses/strains and equivalent stress. These results can be displayed as contour plots. • The displacement results are relative to the base of the structure (the fixed supports). • The velocity and acceleration results include base motion effects (absolute). • Since the directional results from the solver are statistical in nature they cannot be combined in the usual way. For example the X, Y, and Z displacements cannot be combined to get the magnitude of the total displacement. The same holds true for other derived quantities such as principal stresses. • For directional acceleration results, an option is provided to displayed acceleration in G (gravity) by selecting Yes in the Acceleration in G field. • By default the 1 σ results are displayed. You can apply a scale factor to review any multiples of σ such as 2 σ or 3 σ. The Details view as well as the legend for contour results also reflects the percentage (using Gaussian distribution) of time the response is expected to be below the displayed values. • Meaningful equivalent stress is computed using a special algorithm by Segalman-Fulcher. Note that the probability distribution for this equivalent stress is neither Gaussian nor is the mean value zero. However, the “3 σ” rule (multiplying the RMS value by 3) yields a conservative estimate on the upper bound of the equivalent stress. • Force Reaction and Moment Reaction probes can be scoped to a Remote Displacement boundary condition to view Reactions Results. • The use of nodal averaging may not be appropriate in a random vibration analysis because the result values are not actual values but standard deviations. Moreover, the element coordinate system for the shell elements in a surface body may not all be aligned consistently when using the Default Coordinate System. Consider using unaveraged results for postprocessing instead.

Using Command Objects within a Random Vibration Analysis In an effort to minimize disk space usage, only the results from the Random Vibration analysis are kept in the result file. The results from the Modal analysis are removed during the solution. If your command object contains commands which require this data, set the Keep Modal Results property in the Output Controls to Yes.

Response Spectrum Analysis Introduction Response spectrum analyses are widely used in civil structure designs, for example, high-rise buildings under wind loads. Another prime application is for nuclear power plant designs under seismic loads.

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Analysis Types A response spectrum analysis has similarities to a random vibration analysis. However, unlike a random vibration analysis, responses from a response spectrum analysis are deterministic maxima. For a given excitation, the maximum response is calculated based upon the input response spectrum and the method used to combine the modal responses. The combination methods available are: the Square Root of the Sum of the Squares (SRSS), the Complete Quadratic Combination (CQC) and the Rosenblueth’s Double Sum Combination (ROSE). See Response Spectrum Options Group (p. 653) for further details.

Points to Remember • The excitation is applied in the form of a response spectrum. The response spectrum can have displacement, velocity or acceleration units. For each spectrum value, there is one corresponding frequency. • The excitation must be applied at fixed degrees of freedom. • The response spectrum is calculated based on modal responses. A modal analysis is therefore a prerequisite. • If response strain/stress is of interest, then the modal strain and the modal stress need to be determined in the modal analysis. • Because a new solve is required for each requested output, for example, displacement, velocity and acceleration, the content of Commands objects inserted in a response spectrum analysis is limited to SOLUTION commands. • The results from the ANSYS solver are displayed as the model’s contour plot. The results are in terms of the maximum response.

Preparing the Analysis Create Analysis System Basic general information about this topic … for this analysis type: Because a response spectrum analysis is based on modal responses, a modal analysis is a required prerequisite. The modal analysis system and the response spectrum analysis system must share resources, geometry, and model data. From the Toolbox, drag a Modal template to the Project Schematic. Then, drag a Response Spectrum template directly onto the Modal template. Define Engineering Data Basic general information about this topic … for this analysis type: Material properties must be defined in a modal analysis. Nonlinear material properties are not allowed. Attach Geometry Basic general information about this topic

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Linear Dynamic Analysis Types … for this analysis type: There are no specific considerations for a response spectrum analysis. Define Part Behavior Basic general information about this topic … for this analysis type: There are no specific considerations for a response spectrum analysis. Define Connections Basic general information about this topic … for this analysis type: Nonlinear element types are not supported. They will be treated as linear. For example, the contact stiffness is calculated using the initial status without convergence check. Apply Mesh Controls/Preview Mesh Basic general information about this topic … for this analysis type: There are no specific considerations for a response spectrum analysis. Establish Analysis Settings Basic general information about this topic … for this analysis type: Options for Response Spectrum Analyses: • Specify the Number of Modes To Use for the response spectrum calculation. It is recommended to include the modes whose frequencies span 1.5 times the maximum frequency defined in the input response spectrum. • Specify the Spectrum Type to be used for response spectrum calculation as either Single Point or Multiple Points. If the input response spectrum is applied to all fixed degrees of freedom, use Single Point, otherwise use Multiple Points. • Specify the Modes Combination Type to be used for response spectrum calculation. In general, the SRSS method is more conservative than the CQC and the ROSE methods.

Note The Inertia Relief option (under Analysis Settings) for an upstream static structural analysis is not supported in a response spectrum analysis. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types Output Controls (p. 658). By default, only displacement responses are calculated. To include velocity and/or acceleration responses, set their respective Output Controls to Yes. Damping Controls (p. 653) allow you to specify damping for the structure in the response spectrum analysis. Controls include: Constant Damping Ratio, Stiffness Coefficient (beta damping), and a Mass Coefficient (alpha damping). They can also be applied as Material Damping using the Engineering Data tab. For the CQC mode combination type, non-zero damping is required.

Note Damping is not applicable to the SRSS combination method. Damping Controls are not available when the Modes Combination Type property is set to SRSS. Analysis Data Management (p. 664) settings enable you to save solution files from the response spectrum analysis. An option to save the Mechanical APDL application database (db file) from the analysis is provided. Define Initial Conditions Basic general information about this topic … for this analysis type: A specific Modal Environment must be set as an initial condition/environment for response spectrum analysis to be solved. Apply Loads and Supports Basic general information about this topic … for this analysis type: • Supported boundary condition types include fixed support, displacement, remote displacement and body-to-ground spring. If one or more fixed supports are defined in the model, the input excitation response can be applied to all fixed supports. • Remote displacement cannot coexist with other boundary condition types (for example, fixed support or displacement) on the same location for excitation. The remote displacement will be ignored due to conflict with other boundary conditions. • Note that the All boundary condition types for Single Point Response Spectrum only includes those fixed degree of freedoms defined using Fixed Support, Displacement, Remote Displacement and Body-to-Ground Spring. To apply an RS load to All boundary condition types for Single Point Response Spectrum, at least one allowed boundary condition must be defined. • For a Single Point spectrum type, input excitation spectrums are applied to all boundary condition types defined in the model. For Multiple Points however, each input excitation spectrum is associated to only one boundary condition type.

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Linear Dynamic Analysis Types • Three types of input excitation spectrum are supported: displacement input excitation (RS Displacement), velocity input excitation (RS Velocity) and acceleration input excitation (RS Acceleration). See RS Base Excitation (p. 741) for further details. • The input excitation spectrum direction is defined in the global coordinate system for Single Point spectrum analysis. For Multiple Points spectrum analysis, however, the input excitation is defined in the nodal coordinate systems (if any) attached to the constrained nodes. • More than one input excitation, with any different combination of spectrum types, are allowed for the response spectrum analysis. • Specify option to include or not include contribution of high frequency modes in the total response calculation by setting Missing Mass Effect to Yes or No. The option for including the modes is normally required for nuclear power plant design. • Specify option to include or not include rigid responses to the total response calculation by setting Rigid Response Effect to Yes or No. The rigid responses normally occur in the frequency range that is lower than that of missing mass responses, but is higher than that of periodic responses. • Missing Mass Effect is only applicable to RS Acceleration excitation. See the RS Base Excitation section of the Help for more information. • For a Single Point spectrum type, the entire table of input excitation spectrum can be scaled using the Scale Factor setting. The factor must be greater than 0.0. The default is 1.0. Solve Basic general information about this topic … for this analysis type: It is recommended that you review the Solution Information page for any warnings or errors that might occur during the ANSYS solve. Some warning messages will still enable the solve. Review Results Basic general information about this topic … for this analysis type: • To view strain/stress results, a selection must be made in Output Controls of the modal analysis. By default, only displacement results are available. • Applicable results are total deformation, directional (X/Y/Z) displacement, velocity and acceleration. If strain/stress are requested, applicable results are normal strain and stress, shear strain and stress, and equivalent stress. • Equivalent stress is a derived stress calculated using component stresses. • Results are displayed as a contour plot on the model. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types • In addition to standard files generated by the Mechanical APDL application after the solve, the file Displacement.mcom is also made available. If the Output Controls are set to Yes for Calculate Velocity and/or Calculate Acceleration, the corresponding Velocity.mcom and/or Acceleration.mcom are also made available. These files contain the combination instructions including mode coefficients. • Force Reaction and Moment Reaction probes can be scoped to a Remote Displacement boundary condition to view Reactions Results. These probe results are not supported when the Missing Mass Effect and/or Rigid Response Effect properties of the RS Acceleration base excitation are set to Yes.

Magnetostatic Analysis Introduction Magnetic fields may exist as a result of a current or a permanent magnet. In the Mechanical application you can perform 3D static magnetic field analysis. You can model various physical regions including iron, air, permanent magnets, and conductors. Typical uses for a magnetostatic analysis are as follows: • Electric machines • Transformers • Induction heating • Solenoid actuators • High-field magnets • Nondestructive testing • Magnetic stirring • Electrolyzing cells • Particle accelerators • Medical and geophysical instruments.

Points to Remember • This analysis is applicable only to 3D geometry. • The geometry must consist of a single solid multibody part. • A magnetic field simulation requires that air surrounding the physical geometry be modeled as part of the overall geometry. The air domain can be easily modeled in DesignModeler using the Enclosure feature. Ensure that the resulting model is a single multibody part which includes the physical geometry and the air. • In many cases, only a symmetric portion of a magnetic device is required for simulation. The geometry can either be modeled in full symmetry in the CAD system, or in partial symmetry. DesignModeler has a 212

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Magnetostatic Analysis Symmetry feature that can slice a full symmetry model, or identify planes of symmetry for a partial symmetry model. This information is passed to the Mechanical application for convenient application of symmetry plane boundary conditions. • A Magnetostatic analysis supports a multi-step solution.

Preparing the Analysis Create Analysis System Basic general information about this topic … for this analysis type: From the Toolbox, drag the Magnetostatic template to the Project Schematic. Define Engineering Data Basic general information about this topic … for this analysis type: • Magnetic field simulation support 4 categories of material properties: 1. Linear “soft” magnetic materials — typically used in low saturation cases. A Relative Permeability is required. This may be constant, or orthotropic with respect to the coordinate system of the body (See Details view). Orthotropic properties are often used to simulate laminate materials. 2. Linear “hard” magnetic materials — used to model permanent magnets. The demagnetization curve of the magnet is assumed to be linear. Residual Induction and Coercive Force are required. 3. Nonlinear “soft” magnetic material — used to model devices which undergo magnetic saturation. A B-H curve is required. For orthotropic materials, you can assign the B-H curve in any of the orthotropic directions, while specifying a constant Relative Permeability in the other directions. (Specifying a value of “0” for Relative Permeability will make use of the B-H curve in that direction.) 4. Nonlinear “hard” magnetic material — used to model nonlinear permanent magnets. A B-H curve modeling the material demagnetization curve is required. • When an Emag license is being used only the following material properties are allowed: Isotropic Resistivity, Orthotropic Resistivity, Relative Permeability, Relative Permeability (Orthotropic), Coercive Force & Residual Induction, B-H Curve, B-H Curve (Orthotropic), Demagnetization B-H Curve. You may have to turn the filter off in the Engineering Data tab to suppress or delete those material properties/models which are not supported for this license. • Conductor bodies require a Resistivity material property. Solid source conductor bodies can be constant or orthotropic with respect to the coordinate system of the body. Stranded source conductor bodies can only be modeled as isotropic materials.

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Analysis Types • For convenience, a library of common B-H curves for soft magnetic material is supplied with the product. Use the Import tool in Engineering Data to review and retrieve curves for use.

Note In a magnetostatic analysis, you can orient a polarization axis for a Linear or Nonlinear Hard material in either the positive or negative x direction with respect to a local or global coordinate system. Use the Material Polarization setting in the Details view for each body to establish this direction. The Material Polarization setting appears only if a hard material property is defined for the body. For a cylindrical coordinate system, a positive x polarization is in the positive radial direction, and a negative x polarization is in the negative radial direction. Attach Geometry Basic general information about this topic … for this analysis type: There are no specific considerations for a magnetostatic analysis. Define Part Behavior Basic general information about this topic … for this analysis type: There are no specific considerations for a magnetostatic analysis. Define Connections Basic general information about this topic … for this analysis type: Connections are not supported in a magnetostatic analysis. Apply Mesh Controls/Preview Mesh Basic general information about this topic … for this analysis type: • Although your body is automatically meshed at solve time, it is recommended that you select the Electromagnetic Physics Preference in the Details view of the Mesh object folder. • Solution accuracy is dependent on mesh density. Accurate force or torque calculations require a fine mesh in the air regions surrounding the bodies of interest.

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Magnetostatic Analysis • The use of pyramid elements in critical regions should be minimized. Pyramid elements are used to transition from hexagonal to tetrahedral elements. You can eliminate pyramid elements from the model by specifying Tetrahedrons using a Method mesh control tool. Establish Analysis Settings Basic general information about this topic … for this analysis type: The basic controls are: Step Controls (p. 635): used to specify the end time of a step in a single or multiple step analysis. Multiple steps are needed if you want to change load values, the solution settings, or the solution output frequency over specific steps. Typically you do not need to change the default values. Solver Controls (p. 639) allow you to select either a direct or iterative solver. By default the program will use the direct solver. Convergence is guaranteed with the direct solver. Use the Iterative solver only in cases where machine memory is an issue. The solution is not guaranteed to converge for the iterative solver. Nonlinear Controls (p. 655) allow you to modify convergence criteria and other specialized solution controls. These controls are used when your solution is nonlinear such as with the use of nonlinear material properties (B-H curve). Typically you will not need to change the default values for this control. CSG convergence is the criteria used to converge the magnetic field. CSG represents magnetic flux. AMPS convergence is only used for temperature-dependent electric current conduction for solid conductor bodies. AMPS represents current. Output Controls (p. 658) allow you to specify the time points at which results should be available for postprocessing. A multi-step analysis involves calculating solutions at several time points in the load history. However you may not be interested in all of the possible results items and writing all the results can make the result file size unwieldy. You can restrict the amount of output by requesting results only at certain time points or limit the results that go onto the results file at each time point. Analysis Data Management (p. 664) settings enable you to save solution files from the magnetostatic analysis. The default behavior is to only keep the files required for postprocessing. You can use these controls to keep all files created during solution or to create and save the Mechanical APDL application database (db file). Define Initial Conditions Basic general information about this topic … for this analysis type: There is no initial condition specification for a magnetostatic analysis. Apply Loads and Supports

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Analysis Types Basic general information about this topic … for this analysis type: • You can apply electromagnetic boundary conditions and excitations in the Mechanical application. See Electromagnetic Boundary Conditions and Excitations (p. 769) for details. • Boundary conditions may also be applied on symmetry planes via a Symmetry. A Symmetry folder allows support for Electromagnetic Symmetry, Electromagnetic Anti-Symmetry, and Electromagnetic Periodicity conditions. Solve Basic general information about this topic … for this analysis type: The Solution Information object provides some tools to monitor solution progress in the case of a nonlinear magnetostatic analysis. Solution Output continuously updates any listing output from the solver and provides valuable information on the behavior of the structure during the analysis. Any convergence data output in this printout can be graphically displayed as explained in the Solution Information section. Adaptive mesh refinement is available for magnetostatic analyses. Review Results Basic general information about this topic … for this analysis type: A magnetostatic analysis offers several results for viewing. Results may be scoped to bodies and, by default, all bodies will compute results for display. For Inductance or Flux Linkage, define these objects prior to solution. If you define these after a solution, you will need to re-solve.

Rigid Dynamics Analysis Introduction You can perform a rigid dynamics analysis in the Mechanical application using the ANSYS Rigid Dynamics solver. This type of analysis is used to determine the dynamic response of an assembly of rigid bodies linked by joints and springs. You can use this type of analysis to study the kinematics of a robot arm or a crankshaft system for example.

Points to Remember • Inputs and outputs are forces, moments, displacements, velocities and accelerations. • All parts are rigid such that there are no stresses and strain results produced, only forces, moments, displacements, velocities and accelerations.

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Rigid Dynamics Analysis • The solver is tuned to automatically adjust the time step. Doing it manually is often inefficient and results in longer run times. • Viscous damping can be taken into account through springs.

Note Refer to the Multibody Analysis Guide for a reference that is particular to multibody motion problems. In this context, “multibody” refers to multiple rigid parts interacting in a dynamic fashion. Although not all dynamic analysis features discussed in this manual are directly applicable to Workbench features, it provides an excellent background on general theoretical topics. This section contains the following topics: Preparing a Rigid Dynamics Analysis Command Reference for Rigid Dynamics Systems Rigid Body Theory Guide

Preparing a Rigid Dynamics Analysis Create Analysis System Basic general information about this topic … for this analysis type: From the Toolbox, drag a Rigid Dynamics template to the Project Schematic. Define Engineering Data Basic general information about this topic … for this analysis type: Density is the only material property utilized in a rigid dynamics analysis. Models that use zero or nearly zero density fail to solve with the ANSYS Rigid Dynamics solver. Attach Geometry Basic general information about this topic … for this analysis type: Sheet and solid bodies are supported by the ANSYS Rigid Dynamics solver. Plane bodies and line bodies cannot be used. Define Part Behavior Basic general information about this topic … for this analysis type:

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Analysis Types You can define a Point Mass for this analysis type. Part stiffness behavior is not required for the ANSYS Rigid Dynamics solver in ANSYS Workbench. Define Connections Basic general information about this topic … for this analysis type: Applicable connections are joints, springs, and contact. When an assembly is imported from a CAD system, joints or constraints are not imported, but joints may be created automatically after the model is imported. You can also choose to create the joints manually. Each joint is defined by its coordinate system of reference. The orientation of this coordinate system is essential as the free and fixed degrees of freedom are defined in this coordinate system. Automatic contact generation is also available after the model is imported. Apply Mesh Controls/Preview Mesh Basic general information about this topic … for this analysis type: Mesh controls apply to surfaces where contact is defined. Establish Analysis Settings Basic general information about this topic … for this analysis type: For rigid dynamics analyses the basic controls are: Step Controls (p. 635) allow you to create multiple steps. Multiple steps are useful if new loads are introduced or removed at different times in the load history. Rigid dynamics analyses use an explicit time integration scheme. Unlike the implicit time integration, there are no iterations to converge in an explicit time integration scheme. The solution at the end of the time step is a function of the derivatives during the time step. As a consequence, the time step required to get accurate results is usually smaller than is necessary for an implicit time integration scheme. Another consequence is that the time step is governed by the highest frequency of the system. A very smooth and slow model that has a very stiff spring will require the time step needed for the stiff spring itself, which generates the high frequencies that will govern the required time step. Because it is not easy to determine the frequency content of the system, an automatic time stepping algorithm is available, and should be used for the vast majority of models.

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Rigid Dynamics Analysis This automatic time stepping algorithm is governed by Initial Time Step, Minimum Time Step, and Maximum Time Step under Step Controls; and Energy Accuracy Tolerance under Nonlinear Controls. • Initial Time Step: If the initial time step chosen is vastly too large, the solution will typically fail, and produce an error message that the accelerations are too high. If the initial time step is only slightly too large, the solver will realize that the first time steps are inaccurate, automatically decrement the time step and start the transient solution over. Conversely, if the chosen initial time step is excessively small, and the simulation can be accurately performed with higher time steps, the automatic time stepping algorithm will, after a few gradual increases, find the appropriate time step value. Choosing a good initial time step is a way to reduce the cost of having the solver figure out what time step size is optimal to minimize run time. While important, choosing the correct initial time step typically does not have a large influence on the total solution time due to the efficiency of the automatic time stepping algorithm. • Minimum Time Step: During the automatic adjustment of the time step, if the time step that is required for stability and accuracy is smaller than the specified minimum time step, the solution will not proceed. This value does not influence solution time or its accuracy, but it is there to prevent Workbench from running forever with an extremely small time step. When the solution is aborting due to hitting this lower time step threshold, that usually means that the system is over constrained, or in a lock position. Check your model, and if you believe that the model and the loads are valid, you can decrease this value by one or two orders of magnitude and run again. That can, however generate a very large number of total time steps, and it is recommended that you use the Output Controls settings to store only some of the generated results. • Maximum Time Step: Sometimes the time step that the automatic time stepping settles on produces too few results outputs for precise postprocessing needs. To avoid these postprocessing resolution issues, you can force the solution to use time steps that are no bigger than this parameter value. Solver Controls: for this analysis type, allows you to select a time integration algorithm (Runge-Kutta order 4 or 5) and select whether to use constraint stabilization. The default time integration option, Runge-Kutta 4, provides the appropriate accuracy for most applications. When constraint stabilization is employed, Stabilization Parameters are an automatic option. The default, Program Controlled is valid for most applications, however; you may wish to set this option to User Defined and manually enter customized settings for weak spring and damping effects. The default is Off. Nonlinear Controls (p. 655) allow you to modify convergence criteria and other specialized solution controls. Typically you will not need to change the default values for this control. • Energy Accuracy Tolerance: This is the main driver to the automatic time stepping. The automatic time stepping algorithm measures the portion of potential and kinetic energy that is contained in the highest order terms of the time integration scheme, and computes the ratio of the energy to the energy variations over the previous time steps. Comparing

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Analysis Types the ratio to the Energy Accuracy Tolerance, Workbench will decide to increase or decrease the time step.

Note For systems that have very heavy slow moving parts, and also have small fast moving parts, the portion of the energy contained in the small parts is not dominant and therefore will not control the time step. It is recommended that you use a smaller value of integration accuracy for the motion of the small parts. Spherical, slot and general joints with three rotation degrees of freedom usually require a small time step, as the energy is varying in a very nonlinear manner with the rotation degrees of freedom.

Output Controls (p. 658) allow you to specify the time points at which results should be available for postprocessing. In a transient nonlinear analysis it may be necessary to perform many solutions at intermediate time values. However i) you may not be interested in reviewing all of the intermediate results and ii) writing all the results can make the results file size unwieldy. This group can be modified on a per step basis. Define Initial Conditions Basic general information about this topic … for this analysis type: Before solving, you can configure the joints and/or set a joint load to define initial conditions. 1. Define a Joint Load to set initial conditions on the free degrees of freedom of a joint. For the ANSYS Mechanical APDL solver to converge, it is recommended that you ramp the angles and positions from zero to the real initial condition over one step. The ANSYS Rigid Dynamics solver does not need these to be ramped. For example, you can directly create a joint load for a revolute joint of 30 degrees, over a short step to define the initial conditions of the simulation. If you decide to ramp it, you have to keep in mind that ramping the angle over 1 second, for example, means that you will have a non-zero angular velocity at the end of this step. If you want to ramp the angle and start at rest, use an extra step maintaining this angle constant for a reasonable period of time or, preferably, having the angular velocity set to zero. Another way to specify the initial conditions in terms of positions and angles is to use the Configure tool, which eliminates the time steps needed to apply the initial conditions. To fully define the initial conditions, you must define position and velocities. Unless specified by joint loads, if your system is initially assembled, the initial configuration will be unchanged. If the system is not initially assembled, the initial configuration will be the “closest” configuration to the unassembled configuration that satisfies the assembly tolerance and the joint loads.

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Rigid Dynamics Analysis Unless specified otherwise, relative joint velocity is, if possible, set to zero. For example, if you define a double pendulum and specify the angular velocity of the grounded revolute joint, by default the second pendulum will not be at rest, but will move rigidly with the first one. 2. Configure a joint to graphically put the joint in its initial position. See Joint Initial Conditions (p. 543) for further details. Apply Loads and Supports Basic general information about this topic … for this analysis type: The following loads and supports can be used in a rigid dynamics analysis: • Acceleration • Standard Earth Gravity • Joint Load • Remote Displacement • Remote Force • Constraint Equation Both Acceleration and Standard Earth Gravity must be constant throughout a rigid dynamics analysis and cannot be deactivated. For a Joint Load, the joint condition’s magnitude could be a constant value or could vary with time as defined in a table or via a function. Details of how to apply a tabular or function load are described in Defining Boundary Condition Magnitude (p. 848). Details on the Joint Load are included below. In addition, see the Apply Loads and Supports section for more information about time stepping and ramped loads.

Joint Load Interpolation/Derivation For joint loads applied through tabular data values, the number of points input will most likely be less than the number of time steps required to solve the system. As such, n interpolation is performed. The underlying fitting method used for interpolation can be configured using the Fitting Method field (specific to Rigid Dynamics analysis). Options include: • Program Controlled (default): Depending on the Joint Load type, the solver chooses the appropriate interpolation method. Accelerations and Force joint loads use a piecewise linear. Displacement/Rotation/Velocity joint loads use a cubic spline fitting as shown on the following graph:

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A large difference between the interpolated curve and the linear interpolation may prevent the solution from completing. If this is the case and you intend to use the linear interpolation, you can simply use multiple time steps, as the interpolation is done in one time step. • Fast Fourier Transform: Fast Fourier Transform is performed to fit tabular data. Unlike cubic spline fitting, no verification on the fitting quality is performed. The additional cutoff frequency parameter specifies the threshold (expressed in Hz) used to filter high frequencies. Higher cutoff frequency results in a better fitting, but leads to smaller time steps. The following graphs show the effect of cutoff frequency on FFT fitting on a triangular signal using 5 Hz and 10 Hz, respectively.

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Rigid Dynamics Analysis

When defining a joint load for a position and an angle, the corresponding velocities and accelerations are computed internally. When defining a joint load for a translational and angular velocity, corresponding accelerations are also computed internally. By activating and deactivating joint loads, you can generate some forces/accelerations/velocities, as well as position discontinuities. Always consider what the implications of these discontinuities are for velocities and accelerations. Force and acceleration discontinuities are perfectly valid physical situations. No special attention is required to define these velocity discontinuities. Discontinuities can be obtained by changing the slope of a relative displacement joint load on a translational joint, as shown on the following graphs using two time steps:

The corresponding velocity profile is shown here.

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This discontinuity of velocity is physically equivalent to a shock, and implies infinite acceleration if the change of slope is over a zero time duration. The ANSYS Rigid Dynamics solver will handle these discontinuities, and redistribute velocities after the discontinuity according to all active joint loads. This process of redistribution of velocities usually provides accurate results; however, no shock solution is performed, and this process is not guaranteed to produce proper energy balance. A closer look at the total energy probe will tell you if the solution is valid. In case the redistribution is not done properly, use one step instead of two to use an interpolated, smooth position variation with respect to time. Discontinuities of positions and angles are not a physically acceptable situation. Results obtained in this case may not be physically sensible. Workbench cannot detect this situation up front. If you proceed with position discontinuities, the solution may abort or produce false results.

Joint Load Rotations For fixed axis rotations, it is possible to count a number of turns. For 3D general rotations, it is not possible to count turns. In a single axis case, although it is possible to prescribe angles higher than 2π, it is not recommended because Workbench can lose count of the number of turns based on the way you ramp the angle. You should avoid prescribing angular displacements with angles greater than Pi when loading bushing joints, because the angle-moment relationship could differ from the stiffness definition if the number of turns is inaccurate, or in case of Euler angles singularity. It is highly recommended that you use an angular velocity joint load instead of an angle value to ramp a rotation, whenever possible. For example, replace a rotation joint load designed to create a joint rotation from an angle from 0 to 720 degrees over 2 seconds by an angular velocity of 360 degrees/second. The second solution will always provide the right result, while the behavior of the first case can sometimes lead to the problems mentioned above. For 3D rotations on a general joint for example, no angle over 2π can be handled. Use an angular velocity joint load instead.

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Rigid Dynamics Analysis

Multiple Joint Loads On The Same Joint When prescribing a position or an angle on a joint, velocities and acceleration are also prescribed. The use of multiple joint loads on the same joint motion can cause for joint loads to be determined inaccurately. Solve Basic general information about this topic … for this analysis type: Only synchronous solves are supported for rigid dynamics analyses. Review Results Basic general information about this topic … for this analysis type: Use a Solution Information object to track, monitor, or diagnose problems that arise during solution. Applicable results are Deformation and Probe results.

Note If you highlight Deformation results in the tree that are scoped to rigid bodies, the corresponding rigid bodies in the Geometry window are not highlighted. To plot different results against time on the same graph or plot one result quantity against a load or another results item, use the Chart and Table (p. 988) feature. If you duplicate a rigid dynamics analysis, the results of the duplicated branch are also cleared.

Joint Conditions and Expressions When a rotation, position, velocity or angular velocity uses an expression that user the power (^) operator, such as (x)^(y), the table will not be calculated properly if the value x is equal to zero. This is because its time derivative uses log(x), which is not defined for x = 0. An easy workaround is to use x*x*x… (y times), which assumes that y is an integer number and thus can be derived w.r.t time without using the log operator.

Remote Force Remote Force direction can be configured in rigid dynamics analyses using the Follower Load option. Remote direction can be either constant (Follower Load=No, Default), or it can follow the underlying body/part (Follower Load=Yes).

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Command Reference for Rigid Dynamics Systems The Rigid Dynamics solver uses an object-based approach that uses commands based on Python that follow the Python syntax. This section explains this approach and the role of Python in rigid body commands, and provides a library of commands for rigid dynamics analyses (arranged by parent object) and examples of command usage. Topics available in this section include: IronPython References The Rigid Dynamics Object Model Rigid Dynamics Command Objects Library Command Use Examples

IronPython References Because rigid dynamics uses an object-based approach, it is advantageous to have some knowledge of object oriented programming and the Python language for writing commands for the solver. ANSYS Workbench scripting is based on IronPython 2.6, which is well integrated with the rest of the .NET Framework (on Windows) and Mono CLR (on Linux). This makes all related libraries easily available to Python programmers while maintaining compatibility with the Python language. For more information on IronPython, see http://ironpython.codeplex.com/. IronPython is compatible with existing Python scripts; however, not all C-based Python library modules are available under IronPython. For details, refer to the IronPython website. For more information on Python, including a standard language reference, see http://www.python.org/.

The Rigid Dynamics Object Model In the rigid dynamics object-based approach, the Environment is the top level object that allows access to all other underlying objects. The environment is associated with an environment object in the Mechanical tree. Many environments can exist on the same model. The model is called the System in the Rigid Dynamics Object model. The system contains the physical representation of the model, and the environment contains the representation of a given simulation done on the model. This means that Bodies and Joints belong to the systems, and Joint Conditions or Loads are available on the environment. An alternate way to access the objects is by ID. Each object has a unique ID that is also the ID that Mechanical uses. Global object tables help you to get a handle on an object for which you have an ID. For example, a Joint with the ID _jid can be accessed using the following call: Joint= CS_Joint.Find(_jid)

CS_xxx is the table of all xxx type objects. Whenever the ID of an object is not known or if only one occurrence of the object exists in the object model, query the object table to find the first occurrence of a given object type. This is explained in the following example: Environment = CS_Environment.FindFirstNonNull()

GetId() Using this call, each object can return its ID. GetName() Using this call, each object can return its name.

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Rigid Dynamics Analysis SetName(name) Using this call, each name can be set or changed. Some objects will have to be created. For that purpose, you have to call the constructor of the object. For example, to create a constant variable, use: Var = CS_ConstantVariable()

Rigid Dynamics Command Objects Library The following rigid dynamics command objects are available: Actuator Body Body Coordinate System Condition Driver Environment Joint JointDOFLoad Load Measure PointTable Polynomial Tables Relation Spring SolverOptions System Variable Actuator The actuator is the base class for all the Loads and Drivers. ID table: CS_Actuator Members: Condition: All actuators can be conditional. See Condition to create this condition. Member Functions: SetInputMeasure(measure): “measure” is typically the time measure object, but other measures can be used as well. When using an expression to define a load variation, the measure must have only one component (it cannot be a vector measure). The variation can be defined by a constant, an expression, or a table. SetConstantValues(value): “value” is a python float constant. See Relation object for defining a constant. SetTable(table): “table” is a CS_PointTable. SetFunc(string, is_degree): “string” is an expression similar to the one used in the user interface when defining a joint condition by a function. Note that the literal variable is always called “time”, even if you are using another measure as input. «is_degree» is a boolean argument. If the expression uses trigonometric function, it specifies that the input variable should be expressed in degrees.

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Analysis Types Body A body corresponds to a Part in the geometry node of the Mechanical tree. The preset “_bid” variable can be used to find a corresponding body. ID table: CS_Body Example: MyBody = CS_Body.Find(_bid) print MyBody.Name

Members: Name: Name of the body. Origin: Origin Coordinate System of the body. This Coordinate System is the moving coordinate system of one of the joints connected to the body. The choice of this joint, called parent joint, is the result of an optimization that will minimize the number of degrees of freedom of the system. InertiaBodyCoordinateSystem: Inertia body coordinate system of the body. Member Functions: SetMassAndInertia(double mass, double Ixx, double Iyy, double Izz, double Ixy, double Iyz, double Ixz ): Allows you to overwrite the mass and inertia values of a body. SetCenterOfMassAndOrientationAngles(double Xg, double Yg, double Zg, double XYAngle, double YZAngle, double XZAngle): Allows you to overwrite the position of the center of mass and the orientation of the inertia coordinate system. Body Coordinate System The body coordinate system is used to connect a body to joints, to hold the center of mass, or to define load. See Joint to access existing coordinate systems. ID table: CS_BodyCoordinateSystem Members: None Member Functions: RotateArrayThroughTimeToLocal(MeasureValues): Rotates the transient values of a measure to a coordinate system. MeasureValues is a python two-dimensional array, such as that coming out of FillValuesThroughTime or FillDerivativesThroughTime. This function works for 3D vectors such as relative translation between two coordinate systems or 6-D vectors such as forces/moments. RotateArrayThroughTimeToGlobal(MeasureValues): Rotates the transient values of a measure from a coordinate system to the global coordinate system. Derived Classes: None Example: jointRotation = J1.GetRotation() jointVelocity = J1.GetVelocityMeasure()

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Rigid Dynamics Analysis jointAcceleration = J1.GetAccelerationMeasure() jointForce = J1.GetForceMeasure() jointRotationValues =jointRotation.FillDataThroughTime() jointVelocityValues =jointVelocity.FillDataThroughTime() jointAccelerationValues =jointAcceleration.FillDataThroughTime() jointForceValues =jointForce.FillDataThroughTime() nbValues = jointRotationValues.GetLength(0) print jointRotation.Id

print ‘ Time Rotation Velocity Acceleration’ for i in range(0,nbValues): print jointRotationValues[i,0],jointRotationValues[i,1],jointVelocityValues[i,1],jointAccelerationValue fich.close()

Condition Condition is a way to make a load or a joint condition to be active only under some circumstances. A condition is expressed in one of the following forms: 1. MeasureComponent operator threshold 2. LeftThreshold < MeasureComponent < RightThreshold 3. LeftCondition operator RightCondition For case 1: • MeasureComponent is a scalar Measure. • Operator is a math operator chosen from the following list: E_GreaterThan E_LessThan E_DoubleEqual E_ExactlyEqual • Threshold is the threshold value. Example: DispCond = CS_Condition(CS_Condition.E_ConditionType.E_GreaterThan,DispX,0.1)

For case 2: • MeasureComponent is a scalar Measure. • LeftThreshold and RightThreshold are the bounds within which the condition will be true. Example: RangeCond = CS_Condition(DispX,0.0,0.1)

For case 3: • LeftThreshold and RightThreshold are two conditions (case 1, 2 or 3). • Operator is a boolean operator chosen from the following list:

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Analysis Types E_Or E_And Example: BoolCond = CS_Condition(CS_Condition.E_ConditionType.E_Or, RangeCond, DispCond)

Driver A driver is a position, velocity or acceleration, translational or rotational joint condition. Drivers derive from the Actuator class. Corresponding ID table: CS_Actuator Constants: E_Acceleration, E_Position, E_Velocity Members: None Member Functions: CS_Driver(CS_Joint joint, int[] components, E_MotionType driverMotionType): Creation of a joint driver, on joint “joint”, degree of freedom “components”, and with motion type “driverMotionType”. Note that the same driver can prescribe more than one joint motion at the same time. This can be useful if you want to add the same condition to all components of a prescribed motion, for example. Components must be ordered, are zero based, and refer to the actual free degrees of freedom of the joint. Environment This is the top level of the Rigid Dynamics model. ID table: CS_Environment Members: System: Corresponding system. Example: Env=CS_Environment.FindFirstNonNull() Sys = Env.System

Loads: The vector of existing loads. This includes Springs that are considered by the solver as loads, as well as force and torque joint conditions. Example: Xdof = 0 Friction=CS_JointDOFLoad(PlanarJoint,Xdof) Env.Loads.Add(Friction)

Relations: The vector of external constraint equations. Example: rel3=CS_Relation() rel3.MotionType=CS_Relation.E_MotionType.E_Velocity

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Rigid Dynamics Analysis var30=CS_ConstantVariable() var30.SetConstantValues(System.Array[float]([0.])) var31=CS_ConstantVariable() var31.SetConstantValues(System.Array[float]([23.])) var32=CS_ConstantVariable() var32.SetConstantValues(System.Array[float]([37.])) var33=CS_ConstantVariable() var33.SetConstantValues(System.Array[float]([-60.+37.])) rel3.SetVariable(var30) rel3.AddTerm(jp,0,var31) rel3.AddTerm(js3,0,var32) rel3.AddTerm(jps,0,var33) Env.Relations.Add(rel3)

Drivers: The vector of Displacements, Velocity and Acceleration joint conditions. InitialConditions: The vector of Displacements, Velocity, and Acceleration joint conditions to be used only at time=0. PotentialEnergy: Gets the Potential Energy Measure. KineticEnergy: Gets the Kinetic Energy Measure. TotalEnergy: Gets the Total Energy Measure. ActuatorEnergy: Gets the Actuator Energy Measure. RestartTime Specifies the starting time in a restart analysis Member Functions: FindFirstNonNull(): Returns the first environment in the global list. Usually, the table contains only one environment. Hence, thus it is the common way to access the current environment. Example: Env=CS_Environment.FindFirstNonNull()

Derived Classes: None Joint ID table: CS_Joint Constants: For the joint type (E_JointType):

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Analysis Types E_2DSlotJoint, E_BushingJoint, E_CylindricalJoint, E_GeneralJoint, E_FixedJoint , E_FreeJoint, E_PlanarJoint, E_PointOnCurveJoint , E_RevoluteJoint, E_ScrewJoint, E_SingleRotationGeneralJoint, E_SlotJoint, E_SphericalJoint, E_TranslationalJoint, E_TwoRotationGeneralJoint, E_UniversalJoint, Members: Name: Name of the joint ReferenceCoordinateSystem: Joint reference coordinate system Example: J1 = CS_Joint.Find(_jid) CSR = J1.ReferenceCoordinateSystem

MovingCoordinateSystem: Joint moving coordinate system Example: J1 = CS_Joint.Find(_jid) CSM = J1. MovingCoordinateSystem

Type: Joint type IsRevert: The internal representation of the joint can use flipped reference and mobile coordinate systems. In that case, all the joint results (e.g., forces, moments, rotation, velocities and acceleration) must be multiplied by -1 to go from their internal representation to the user representation. As transient values of joint measures are giving the internal representation, use this IsRevert information to know if results should be negated. AccelerationFromVelocitiesDerivatives: When extracting joint degrees of freedom on joints that return true, accelerations should be done by using the time derivatives of the joint velocity measure. On joints that return false, extracting of the joint DOFs derivatives should be done using the joint acceleration measure. It is important to check this flag first. Using the wrong method to query joint acceleration would fail or give incorrect results. Example: if Universal.AccelerationFromVelocitiesDerivatives: UniversalAccelerationValues=UniversalVelocityM.FillDerivativesThroughTime() else: UniversalAcceleration = Universal.GetAcceleration() UniversalAccelerationValues=UniversalAcceleration.FillDataThroughTime()

Member Functions: GetVelocity(): Returns the joint velocity measure. The size of this measure is the number of degrees of freedom of the joint. The derivatives of this measure give access to the joint accelerations.

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Rigid Dynamics Analysis GetRotation(): Returns the joint rotation measure. The type of measure depends on the joint number of rotational degrees of freedom (E_1DRotationMeasure, E_3DRotationMeasure, E_UniversalAngles). These rotations components are relative to the reference coordinate system of the joint. GetTranslation(): Returns the joint translation measure. The length of this measure will be the number of translational degrees of freedom of the joint. The translation components are expressed in the reference coordinate system of the joint. GetForce(): Returns the joint force measure. The length of this measure is always 6 (3 forces components, 3 torque component). This force measure is the total force/moment, including constraint forces/moment, external forces/moment applied to the joint, and joint internal forces/moment, such as elastic moment in a revolute joint that has a stiffness on the Z rotation axis. The force measure components are expressed in the global coordinate system. Note that the sign convention is different from the sign convention used in the Joint Probes in Mechanical. GetAcceleration(): Returns the joint acceleration measures on the joints that are constraint equations based. See the AccelerationFromVelocitiesDerivatives member to see when this function should be used. Example: J1 = CS_Joint.Find(_jid) jointRotation = J1.GetRotation() jointVelocity = J1.GetVelocityMeasure() jointAcceleration = J1.GetAccelerationMeasure() jointForce = J1.GetForceMeasure()

Derived Classes: On SphericalJoint, SlotJoint, BushingJoint, FreeJoint, GeneralJoint. Member Function AddStop(angle_max, restitution_factor): Adds a spherical stop to a joint that has three rotations. A spherical stop constrains the motion of the X and Y rotational degrees of freedom, to give to the joint the behavior of a loose revolute joint, with a rotational gap. This will allow easier handling of over-constrained systems and building higher fidelity models without having to use contact. angle_max is the angle between the reference coordinate system Zr axis and the moving coordinate system Zm. Zr is the natural revolute axis. restitution_factoris the restitution factor, similar to other joint stops.

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Zr Zm

Yr

n θ Xr On CylindricalJoint: ReplaceByScrew(pitch): Creates a relation between the translational and the rotational degrees of freedom of a cylindrical joint. Note that the pitch is in the current length unit. On Bushing Joint: GetBushingAngles(): Returns the measure of the joint angles. This measure is used to compute the forces and torques developed in the joint. Note that this is only available for post processing operations, as the measure does not exist before the solve has been performed. JointDOFLoad JointDOFLoads are loads applied on a given degree of freedom of a joint. The load is applied in the joint reference coordinate system. JointDOFLoad derives from Load. The constructor for CS_JointDOFLoad is called as follows : Load=CS_JointDOFLoad(joint,dof) • “joint” is a joint object. • “dof” is an integer that defines the joint degree of freedom to be included in the term. The ordering of the degrees of freedom sets the translation degrees of freedom first. The degrees of freedom numbering is zero based. For example, in a slot joint, the translational degree of freedom is 0, while the third rotational degree of freedom is 3. Members: None

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Rigid Dynamics Analysis Member functions: None Load Loads derive from the Actuator class. They are derived from various types of loads, such as the CS_JointDOFLoad. Corresponding ID table: CS_Actuator Members: None Members Functions: None Measure: Most of the useful measures are already pre-existing on the rigid dynamics model, and you need to use other object “get” functions to access them but others can be created before solving, in order to perform custom postprocessing or to use their value as input for a joint condition. Other measures can be created, for example to express conditions. In that case, for the measure to be computed at each time step, it needs to be added to the system (see component measure example below) ID table: CS_Measure Constants: For the measure type (E_MeasureType): E_1DRotationJoint, E_3DRotationBody, E_3DRotationJoint, E_Acceleration, E_ActuatorStatus, E_ActuatorEnergy, E_AnsysJointForceAndTorque, E_BodyAcceleration, E_BodyIntertialBCSQuaternion, E_BodyRotation, E_BodyTranslation, E_CenterOfGravity, E_Component, E_Constant, E_Contact, E_ContactForce, E_ContactVelocity, E_Counter, E_Displacement, E_Distance, E_DistanceDot, E_Divides, E_EigenValue, E_DOFSensitivity, E_Dot, E_ElasticEnergy, E_Energy, E_EulerAngles, E_ForceMagnitude, E_Forces, E_IntegratedOmega, E_JointAcceleration, E_JointDOFFrictionCone, E_JointDriverForce, E_JointForce, E_JointMBDVelocity, E_JointNormalForce, E_JointTranslation, E_JointRotation, E_JointVelocity, E_KineticEnergy, E_MassMomentsOfInertia, E_MeasureDotInDirectionOfLoad, E_Minus, E_Multiplies, E_Norm , E_Omega, E_OmegaDot, E_OutputContactForce, E_Plus, E_PointOnCurveGeometryMeasure, E_PointOnCurveJointSigmaMeasure, E_PointToPointRotation, E_PointToPointRotationDot, E_Position, E_PotentialEnergy, E_RadialGap, E_ReferenceEnergy, E_RelativeAcceleration, E_RelativePosition, E_RelativeVelocity, E_RotationalRelativeDOF, E_RotationMatrix, E_SphericalStop, E_StopVelocity, E_StopStatus, E_Time, E_TimeStep, E_TranslationalJoint, E_UniversalAngles, E_UnknownType, E_User, E_Velocity, E_Violation, E_XYZAnsysRotationAngles, E_ZYXRotationAngles, Members: Length: Number of components of the measure Example: nbValues = Measure.Length Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types Type: Measure type Calculation Method: A measure can use direct calculation, or be time integrated. On a measure that uses direct calculation, it is possible to retrieve the measure value through time. On a measure that is time-integrated, both values and time derivatives can be retrieved. Name: Measure Name Member Functions: FillValuesThroughTime(): Returns a two dimensional array. This function shall be called after the solution has been performed. The first dimension of the returned array is the number of time values in the transient. The second dimension is the size of the measure plus one: the first column contains the time values, while the subsequent columns contain the corresponding measure values. FillDerivativesThroughTime(): Returns a two dimensional array. This function shall be called after the solution has been performed. The first dimension of the returned array is the number of time values in the transient. The second dimension is the size of the measure plus one: the first column contains the time values, while the subsequent columns contain the corresponding measure derivatives. These derivatives are available on measures that are time integrated. To know if a measure is time integrated, use the CalculationMethod member. Derived Classes: CS_JointVelocityMeasure: Joint velocities, both translational and rotational, are expressed in the joint reference coordinate system. The number of components is the number of translational degrees of freedom plus the number of rotational degrees of freedom. For example, for a revolute joint, the size of the joint velocity measure is 1. It contains the relative joint rotation velocity along the z axis of the joint reference coordinate system. For a slot joint, the size of the measure will be 4; one component for the relative translational velocity, and the 3 components of the relative rotational velocity. The joint velocity measure can be obtained from the joint using the “GetVelocity” function. Rotational velocities are expressed in radians/second. CS_JointAccelerationMeasure: Joint accelerations, both translational and rotational, are expressed in the joint reference coordinate system. The number of components is the number of translational degrees of freedom plus the number of rotational degrees of freedom. The joint acceleration measure can be obtained from the joint using the “GetAcceleration” function. CS_JointRotationMeasure: • For revolute joints, cylindrical joints, or single rotation general joints, this measure has only one component — the relative angle between the reference and the moving coordinate system of the joint. Rotations are expressed in radians. • For slots, spherical joints, bushing joints, and 3 rotation vectors, this measure contains values that are not directly usable.

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Rigid Dynamics Analysis • For universal joints, it contains the two joint axis rotational velocities. (The first one along the X axis of the reference coordinate system and the second along the Z axis of the moving coordinate system). These angles are expressed in radians. CS_JointTranslationMeasure: : This measure contains only the joint relative translations, expressed in the joint reference coordinate system. The joint translation measure can be obtained from the joint using the “GetTranslation” function. CS_JointForceMeasure: This measure contains the total forces and moment that develop in the joint. This includes constraint forces, elastic forces and external forces. The joint velocity measure can be obtained from the joint using the “GetForce” function. CS_ComponenetMeasure: This measure allows the extraction of one component of an existing measure. This component can be expressed in a non default coordinate system. Example: Planar = CS_Joint.Find(_jid) Vel = Planar.GetVelocity() Xglobaldirection = 0 VelX = CS_ComponentMeasure(Vel,Xglobaldirection) Sys.AddMeasure(VelX)

PointTable Corresponding ID table: CS_PointTable Members Functions: CS_PointTable( tab ): “tab” is a two dimensional array, where the first column contains the input values, and the second column contains the corresponding output values. Example: tab = System.Array.CreateInstance(float,6,2) tab[0,0]=-100. tab[1,0]=-8. tab[2,0]=-7.9 tab[3,0]= 7.9 tab[4,0]= 8. tab[5,0]= 100. tab[0,1]=1.0 tab[1,1]=1.0 tab[2,1]=0.1 tab[3,1]=0.1 tab[4,1]=1.0 tab[5,1]=1.0 Table = CS_PointsTable(tab);

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Here, the output (shown as Stiffness in the chart above) varies in a linear, piece-wise manner. For values of input less than -8.0 or greater than 8.0, the output is equal to 1.0. For values between -7.9 and +7.9, the output is 0.1. The transition is linear between -8.0 and -7.9 , and as well between +7.9 and +8.0. Polynomial Table Corresponding ID: CS_PolynomialTable Create a polynomial relation between sizeIn inputs and sizeOut outputs using the following function:

=

+

∑ 



 

⋯

 

⋯

  



Where i denotes the index of input and goes from 1 to n (sizeIn), j denotes the index of output (from 1 to sizeOut). Member Functions: CS_PolynomialTable(): Creates an empty polynomial table. Initialize(constant): Specialized for 1×1 table. Initializes the table to be a 1 input, 1 output table, and sets the constant term (constant is a float value). Initialize(sizeIn,sizeOut,constantValues): (generic version) Initializes the table with sizeIn inputs and sizeOut outputs and sets the constant terms. sizeIn and sizeOut are two integer values, and constantValues is an array of sizeOut float values. AddTerm(coefficient,order): Specialized for 1×1 table. Adds one monomial term to the table. The coefficient is a float value and order is an integer value giving the power of the input. AddTerm(coefficients,orders): (generic version) Adds one monomial term to the table. The coefficients are given by a sizeOut float array and the power for each input by an array of sizeIn integers. Relation The relation object allows you to write constraint equations between degrees of freedom of the model. For example, two independent lines of shaft can be coupled using a relation between their rotational velocities. If you have a gear coupling between two shafts where the second shaft rotates twice faster than the first one, you can write the following equation: 2.0 X Ω1 + Ω2 = 0

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Rigid Dynamics Analysis where Ω1 and Ω2 are joint rotational velocities. This relation contains two terms and a constant right hand side equal to zero. The first term (2 X Ω1) can be described using the following information: • A joint selection • A joint degree of freedom selection • The nature of motion that is used in the equation (joint velocities, which is the most common case). For convenience purpose, the nature of motion on which the constraint equation is formulated is considered as being shared by all the terms in the relation. This information defines Ω1 • The factor 2.0 in the equation can be described by a constant variable, whose value is 2.0 ID table: CS_Actuator The coefficients of the relation can be constant or variable; however, the use of non-constant coefficients is limited to relations between velocities and relations between accelerations. If non-constant coefficients are used for relations between positions, the solution will not proceed. Constants: E_Acceleration, E_Position, E_Velocity Members: None Member Functions: SetRelationType(type): type of relation, with type selected in the previous enumeration AddTerm(joint, dof, variable): Adds a term to the equation. • “joint” is a joint object. • “dof” is an integer, defining the joint degree of freedom to be included in the term. The ordering of the degrees of freedom sets the translation degrees of freedom first, and that the degrees of freedom numbering is zero based. For example, in a slot joint, the translational degrees of freedom is 0, while the third rotational degree of freedom is 3. • “variable” is a variable object. SetVariable(variable): sets the right hand side of the relation. “variable” is a variable object. SolverOptions Global object that holds several parameters to tune the behavior of the Rigid Body solver Members: FrictionForShock (default 0): set to 1 to include friction for contact collision. Spring Corresponding ID table: CS_Actuator

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Analysis Types Members: None Member Functions: ToggleCompressionOnly() Calling this function on a translational spring will make the spring develop elastic forces only if its length is less than the spring free length. The free length has to be defined in the regular spring properties. ToggleTensionOnly() Calling this function on a translational spring will make the spring develop elastic forces only if its length is greater than the free length of spring. The free length has to be defined in the regular spring properties. SetLinearSpringProperties(system, stiffness, damping) Allows you to overwrite damping and stiffness of a translational spring. This can be useful to parameterize these properties. For example, system is the system object, stiffness and damping are the double precision values of stiffness and damping. SetNonLinearSpringProperties(table_id) Allows you to replace the constant stiffness of a spring with a table of ID table_id that gives the force as a function of the elongation of the spring. The table gives the relation between the force and the relative position of the two ends. GetDamper() The user interface has stiffness and damping properties of the spring. Internally, the Spring is made of two objects; a spring and a damper. This function allows you to access the internal damper using the Spring object in the GUI. Derived Classes: None System Corresponding ID table: CS_System Members: None Member Functions: AddMeasure(measure): Adds a measure to the system, to be calculated during the simulation. This function has to be called prior to solving so that the measure values through time can be retrieved. (istat,found,measure)=FindOrCreateInternalMeasure( MeasureType): Extracts an existing global measure on the system. Supported measure types are: E_Energy, E_PotentialEnergy, E_ElasticEnergy, E_KineticEnergy, and E_Time. Derived Classes: None Variable A variable is an n-dimensional vector quantity that varies over time. It is used to define the variation of a load or a joint condition, or to express the coefficients in a relation between degrees of freedom. For

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Rigid Dynamics Analysis convenience purpose, the solver allows the creation of constant variables, where only the value of the constant has to be provided. More complex variables can be built using a function variable. A function variable is a function of input , where input is given by a measure and function is described by a table. In some cases, you will be able to replace the table or the measure of an internal variable as used in a joint condition. ID table: CS_Variable Members: None Member Functions: SetConstantValues(value): “value” is an array, whose size is equal to the size of the table. To create a constant scalar variable, the value can be defined as shown in the following example: value = System.Array[float]([1.0]): “System”, “Array”, and “float” are part of the Python language. The result of this is an array of size one, containing the value 1.0. AddInputMeasure(measure): “measure” is a measure object. The same variable can have more than one measure. The input variable of the variable is formed by the values of the input measure in the order that they have been added to the list of input measures. SetTable(table): “table” is a CS_PointTable. SetFunc(string, is_degree): “string” is an expression similar to the one used in the user interface when defining a joint condition by a function. Note that the literal variable is always called “time”, even if you are using another measure as input. «is_degree» is a boolean argument. If the expression uses a trigonometric function, it specifies that the input variable should be expressed in degrees. Derived Classes: ConstantVariable

Command Use Examples The following command use examples are included in this section: Screw Joint Constraint Equation Joint Condition: Initial Velocity Joint Condition: Control Using Linear Feedback Non-Linear Spring Damper Spherical Stop Export of Joint Forces Breakable Joint

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Analysis Types

Screw Joint

This example considers a screw joint. While the screw joint is not displayed by the Mechanical GUI, there are two ways to create a screw joint. • Use a cylindrical joint and link translation and rotation with the following relation: Tz = Pitch * Rz • Modify an existing cylindrical joint into a specialized screw joint. Retrieve the joint using its ID (_jid) to the joint, then replace the joint with a screw joint giving the pitch. The commands for this approach are shown below: Joint = CS_Joint.Find(_jid) Pitch = 2 Joint.ReplaceByScrew(Pitch)

Note that the pitch value is unit dependant. The joint where these commands are inserted must be a cylindrical joint.

Constraint Equation This example considers the gear mechanism shown below.

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Rigid Dynamics Analysis

A relation is created between two revolute joints to simulate a gear with a ratio 2 M. Commands are used to enforce the ratio of velocities between the two wheels, and create a linear relation between rotational velocities, defined by: (1)*ω 1 + (-2)*ω2 = 0 First, the joint objects are retrieved using their IDs: j1id = CS_Joint.Find(_jid) j2id = CS_Joint.Find(_jid)

Next, the relationship between the two wheels is defined. The complete list of commands is shown below. A description of these commands follows.

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Analysis Types

1. A relation object is created and specified as a relation between velocities: rel=CS_Relation() rel.MotionType=CS_Relation.E_MotionType.E_Velocity

2. The constant coefficients that appear in the relation are created. The first constant term is created by: var1=CS_ConstantVariable() var1.SetConstantValues(System.Array[float]([1.]))

3. The second coefficient and constant right hand side are created by: var2=CS_ConstantVariable() var2.SetConstantValues(System.Array[float]([-2.])) varrhs=CS_ConstantVariable() varrhs.SetConstantValues(System.Array[float]([0.]))

4. The first term of relation (1) X ω_1 is added to the relation object: rel.AddTerm(j1id,0,var1)

The first argument is the joint object. The second argument defines the DOF (degrees of freedom) of the joint that are involved in the relation. Here, 0 represents the rotation, which is the joint’s first and only DOF is the rotation. 5. The second term and right hand side are introduced in the same manner: rel.AddTerm(j2id,0,var2) rel.SetVariable (varrhs)

6. The relation is added to the list of relations: Env=CS_Environment.GetDefault() Env.Relations.Add(rel)

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Rigid Dynamics Analysis

Joint Condition: Initial Velocity This example shows how to impose an initial velocity to a joint. A velocity driver (joint condition) is created using commands and added to the list of initial conditions. During the transient solve, initial conditions are applied only at t=0. The complete list of commands and their explanation follows. Joint=CS_Joint.Find(_jid) driver=CS_Driver(joint,System.Array[int]([0]),CS_Driver.E_MotionType.E_Velocity) Env=CS_Environment.GetDefault() Sys=Env.System (ret,found,time) = Sys.FindOrCreateInternalMeasure(CS_Measure.E_MeasureType.E_Time) driver.SetInputMeasure(time) driver.SetConstantValues(System.Array[float]([-4.9033])) Env.InitialConditions.Add(driver)

1. The joint is retrieved using its ID(_jid): Joint=CS_Joint.Find(_jid)

2. A velocity driver (imposed velocity) is created on this joint: driver=CS_Driver(joint,System.Array[int]([0]),CS_Driver.E_MotionType.E_Velocity)

The driver constructor takes the joint instance as the first argument. The second argument is an array of integer that defines which DOFs are active. The physical meaning of these integers is dependent of the joint. For instance, if the underlying joint is a translation joint, 0 is the translation along x. But if the joint is revolute, 0 now is the rotation along z axis. Similarly, for a cylindrical joint,0 is is the translation along z, and 1 is the rotation. The last argument gives the type of driver here velocity. Drivers can be one of three types: position, velocity, or acceleration: 3. The default environment and corresponding system are retrieved Env=CS_Environment.GetDefault() Sys=Env.System

4. This command returns an instance on an internal measure. It is often used to obtain the instance of the time measure: (ret,found,time) = Sys.FindOrCreateInternalMeasure(CS_Measure.E_MeasureType.E_Time)

5. The time measure is specified as the input measure for the driver and a constant value is given to the driver. As the driver may be applied to several components of the joint, the values are given as an array of float: driver.SetInputMeasure(time) driver.SetConstantValues(System.Array[float]([-4.9033]))

6. The driver is added to the list of initial conditions. Consequently, it will be active only at t=0 and will give an initial velocity to the joint: Env.InitialConditions.Add(driver)

Joint Condition: Control Using Linear Feedback In this example, an existing load is modified to apply a torque proportional to the joint velocity. Two Methods are discussed: Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

245

Analysis Types Method 1 Obtain the velocity measure from the joint.

Next, modify an existing moment in order to use the velocity measure as its input measure.

Method 2 Using this method, the load is created entirely using commands. These commands are shown below.

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Rigid Dynamics Analysis

Non-Linear Spring Damper This example shows how the behavior of a spring can be altered to introduce a non-linear force-displacement relationship. The complete list of commands is shown below. A description of these commands follows.

1. Retrieve the spring object using its ID: Spring=CS_Actuator.Find(_sid)

2. Create an array of real values and fill it with the pairs of values (elongation, force): Spring_table=System.Array.CreateInstance(float,7,2)

In this command, 7 represents the number of rows and 2 for the number of columns. The first column gives elongation and the second, the corresponding force value. This command generates a PointsTable assigned to the spring, as shown below.

Each spring object in the Mechanical GUI is actually a combination of a spring and a damper. The GetDamper method allows you to retrieve the damper object on a given spring, as shown below.

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Analysis Types

3. Introduce a table is to define a non-linear force velocity relation: Damper=spring.GetDamper()

Spherical Stop This example describes the implementation of a spherical stop. A spherical stop is a joint that has 3 rotations (joints include spherical, slot, bushing, free and general joints). This specific type of stop creates a limit to the angle between the z-axis of the reference frame and the z-axis of the moving frame. This functionality is available using the following command: AddStop(angle_max, restitution_factor)

For example, to add a spherical stop for an angle value equal to 0.45 radians and a restitution factor equal to 1.0, the following command would be issued: Joint.AddStop(0.45,1.0)

An example of the model and the results of this command are shown below.

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Rigid Dynamics Analysis

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Analysis Types

Export of Joint Forces In this example joint forces are extracted in the local coordinate system, rotated into the global coordinate system, and written into an ASCII File First, the joint is retrieved by inserting the following command on the corresponding joint in the tree: TopRevolute = CS_Joint.Find(_jid)

Next, the commands object shown below is inserted in the result node. An explanation of these commands follows.

1. Get measures from the joint: TopRevoluteRotation = TopRevolute.GetRotation()

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Rigid Dynamics Analysis 2. Extract transient values for this measure: TopRevoluteRotationValues=TopRevoluteRotation.FillValuesThroughTime()

3. Get angle derivatives by extracting the time derivatives of the measure: TopRevoluteRotationDerivatives=TopRevoluteRotation.FillDerivativesThroughTime()

4. Count the number of components of this array: nbValues = TopRevoluteRotationValues.GetLength(0)

5. Open the ASCII output file: fich=open(r»TopRevoluteRotation.csv»,’w’) fich.write(‘Time,Rotation,Velocity\n’)

6. Loop over all time values, and write values: for i in range(0,nbValues): fich.write(‘{0:4.3f},{1:11.4e},{2:11.4e}\n’.format(TopRevoluteRotationValues[i,0], TopRevoluteRotationValues[i,1],TopRevoluteRotationDerivatives[i,1])) fich.close()

7. Check if joint is « revert » or not: IsRevert = TopRevolute.IsRevert if IsRevert: fact = -1.0 else: fact = 1.0

8. Extract Force Measure and write them into the file: TopRevoluteForce = TopRevolute.GetForce(); TRF=TopRevoluteForce.FillValuesThroughTime() fich=open(r»TopRevoluteForce.csv»,’w’) fich.write(‘Time,FX,FY,FZ,MX,MY,MZ\n’) for i in range(0,nbValues): fich.write(‘{0:4.3f},{1:11.4e},{2:11.4e},{3:11.4e},{4:11.4e}, {5:11.4e},{6:11.4e}\n’.format(TRF[i,0],fact*TRF[i,1], fact*TRF[i,2],fact*TRF[i,3],fact*TRF[i,4],fact*TRF[i,5],fact*TRF[i,6]))

fich.close()

9. Get the joint reference coordinate system, and rotate the forces from the global coordinate system to the joint coordinate system: TopRevolute.ReferenceCoordinateSystem.RotateArrayThroughTimeToLocal(TRF) fich=open(r»TopRevoluteForceRotated.csv»,’w’) fich.write(‘Time,FX,FY,FZ,MX,MY,MZ\n’) for i in range(0,nbValues): fich.write(‘{0:4.3f},{1:11.4e},{2:11.4e},{3:11.4e},{4:11.4e},{5:11.4e}, {6:11.4e}\n’.format(TRF[i,0],fact*TRF[i,1],fact*TRF[i,2],fact*TRF[i,3], fact*TRF[i,4],fact*TRF[i,5],fact*TRF[i,6])) fich.close()

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Analysis Types

Breakable Joint This example considers a breakable joint. A breakable joint is a joint that cannot withstand an internal force higher than a given value. To create a breakable joint: 1. Get the joint by inserting a command on a planar joint: joint=CS_Joint.Find(_jid)

2. Create a joint condition to prescribe zero velocity on the two translational degrees of freedom: driver=CS_Driver(joint,System.Array[int]([0,1]),CS_Driver.E_MotionType.E_Velocity)

3. Define the value of the velocity, then retrieve the time measure: Env=CS_Environment.GetDefault() Sys=Env.System (ret,found,time)=Sys.FindOrCreateInternalMeasure(CS_Measure.E_MeasureType.E_Time)

4. Define the time as variable, and use constant values for the two components: driver.SetInputMeasure(time) driver.SetConstantValues(System.Array[float]([0.,0.]))

Next, make the driver only active if the force in the joint is less than a maximum threshold of 3N. To do that, create a Condition based on the joint force measure norm. 5. Retrieve the force on the joint: force=joint.GetForce()

6. Create a component measure, that is the norm 2 of the force. To be computed at each time step, this measure has to be added to the system. norm=CS_ComponentMeasure(force,-2) Sys.AddMeasure(norm)

7. Now, create the condition and assign it to the driver: cond=CS_Condition(CS_Condition.E_ConditionType.E_LessThan,norm,3.0) driver.Condition=cond

8. Finally, add the driver to the environment: Env.Drivers.Add(driver)

Rigid Body Theory Guide Rigid body dynamics is the study of the motion of assemblies of bodies that do not deform, but instead move rigidly in 3D space. The free motion of bodies is restrained by joints. Every joint links two bodies in two points. These joints are idealizations of the contact between the two bodies. Joints are characterized by the motion that they allow between the two bodies that they connect. For example, a revolute joint allows one relative rotation between two bodies, constrains all three relative translations, and blocks the two other relative rotations.

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Rigid Dynamics Analysis The primary unknowns of a rigid dynamics solution are the translation and rotation of each body and the motion in the joints themselves. The output quantities of rigid body dynamics are the forces that develop in the joints and flow through the rigid bodies, as opposed to a structural analysis where the output quantities are strains or stresses. The following topics are discussed in this section: Degrees of freedom Shape Functions Equations of Motion Time Integration Geometric Correction and Stabilization Contact and Stops References

Degrees of freedom This section discusses the options available when selecting degrees of freedom (DOFs) in a rigid body assembly and their effect on simulation time. The double pendulum model shown below is considered in this section. The first body in this model (in blue) has center of gravity G1. This body is linked to the ground through revolute joint R1, and linked to a second body through revolute joint R2. The second body (in red) has center of gravity G2, and is linked to the first body through revolute joint R2. Figure 1: Double Pendulum Model

The two bodies in this model are rigid, meaning that the deformations of these bodies are neglected. The distance between any two points on a single rigid body is constant regardless of the forces applied to it. All the points on the body can move together, and the body can translate and rotate in every direction. Many parameters are available to describe the body position and orientation, but the parameter usually chosen for the translation is the position of the center of mass with respect to a ground coordinate Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

253

Analysis Types system. It is extremely difficult to represent 3D rotations for the orientation in a universal way. A sequence of angles is often used to describe the orientation, but some configurations are singular. An option frequently used to describe the orientation in computer graphics is the use of quaternion (also known as Euler-Rodrigues parameters); however, this option uses four parameters instead of three, and does not have a simple interpretation. A natural choice of parameters to describe the position and orientation of the double pendulum model, is to use the position and orientation of the two individual bodies. In other words, use three translational and rotational degrees of freedom for each body, and introduce the joints using constraint equations. The constraint equations used state that the two points belonging to the two bodies linked by the revolute joint are always coincident, and that the rotation axis of the joint remains perpendicular to the other body. This requires five constraint equations for each revolute joint. The selected degrees of freedom (six DOFs per body and certain joints based on constraint equations) are considered “absolute” parameters. Figure 2: Absolute Degrees of Freedom

The model shown in Figure 2: Absolute Degrees of Freedom (p. 254) depicts global parameters in 2-D for the double pendulum. Body 1 and 2 are respectively parameterized by X and Y translation and theta rotation. Because the model has only two degrees of freedom, it does not require any additional constraint equations. Global parameters for the body are chosen independently of the joints that exist between those bodies. When these joints are known, parameters for the joints can be chosen that reduce the number of parameters and constraint equations needed. For this example, the first degree of freedom is defined as the relative orientation of the first body with respect to the ground. The second degree of freedom is defined as the relative orientation of the second body with respect to the first body. Relative degrees of freedom are shown in the figure below:

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Rigid Dynamics Analysis Figure 3: Relative Degrees of Freedom

Next, a third body is added to the model that is grounded on one side and linked to the second body with another revolute joint, as shown below: Figure 4: Closed Loop Model

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Analysis Types The closed loop model shown above has three bodies (plus the ground) and four revolute joints. The degrees of freedom can be chosen for the example as follows: Θ1 — The relative rotation of body 1 with respect to ground Θ2 — The relative rotation of body 2 with respect to body 1 Θ3 — The relative rotation of body 3 with respect to ground The fourth revolute joint cannot be based on degrees of freedom because both the motions of Body 2 and Body 3 are already defined by existing degrees of freedom. For this joint, constraint equations are added to the relative degree of freedom parameters. Θ1, Θ2, and Θ3 will be the degrees of freedom, and the corresponding joints will be topological joints. The fourth joint will be based on a constraint equation. Constraint equation-based joints are also known as kinematic joints. Kinematic joints are needed when the model has closed loops, i.e., when there is more than one way to reach the ground from a given body in the system. To determine which joints will be topological joints and which will be kinematic joints, a graph is constructed to show connections where the bodies are vertices and the joints are arcs. This graph is decomposed into a tree, and the joints corresponding to arcs that are not used in the tree are transformed into kinematic joints. The Model Topology view displays whether joints are based on degrees of freedom or constraint equations.

Kinematic Variables vs. Geometry Variables Euler’s theorem on rotations states that an arbitrary rotation can be parameterized using three independent parameters. The choice of these three parameters is not unique, and many choices are possible. For example: • A sequence of three rotations, as introduced by Euler (the first rotation around X, the second rotation around the rotated Y’ axis, and the third rotation around the updated Z’’ axis). Many other sequences of rotations exist, among them the Bryant angles. • The 3 components of the rotation vector • Etc… Unfortunately, these minimal sets of parameters are not perfect. Sequences of angles usually have some singular configurations, and the composition of rotations using these angles is simple. This composition of rotation is intensively used in transient simulation. For example, it can be used to prevent the use of the rotation vector. Another option is to use the 3×3 rotation matrix. Composition of rotations is easy with this option, as it corresponds to matrix multiplication; however, this matrix is an orthogonal matrix, and time integration must be done carefully to maintain the matrix properties. A good compromise is to use quaternion, which have 4 parameters and a normalization equation. Once rotation parameters have been selected, the time derivatives of these parameters have to be established:

=

256

ur 

(8)

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Rigid Dynamics Analysis

ur where

is the angular velocity vector.

Two sets of variables exist:

ur

• Kinematic variables, expressed as {q}:

as long as the translational velocities.

• Geometric variables, expressed as {g}, as well as the position variables for the translations. The geometric variables are obtained by time-integration of the kinematic variables.

Shape Functions Shape functions, also called generalized velocities, are the projections of the velocity of material point Mk attached to body k on the kinematic variables of the model. Generalized velocities of a material point are depicted in the figure below: Figure 5: Generalized Velocities of a Material Point 0

L(L(L(k)))

L(L(k))

L(k)

k Mk

Because of the choice of relative degrees of freedom, the velocity of Mk is a function of kinematic variables of the joint located between body k and its parent body L(k), as well as those of the joint between L(k) and L(L(k)), continuing until the ground is reached.

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257

Analysis Types To understand how these generalized velocities are formed, it helps to first focus on the contribution of the first joint of the chain (pictured below). This joint is located between body k and its parent, L(k). Figure 6: Contribution of the Parent Joint to the Generalized Velocities

0 L(k)

Rk

Vk/L(k)

Ω k/L(k) 0k

k Mk

Because body k is rigid, the velocity of point Mk with respect to the ground 0 can be expressed from the velocity of point Ok. Point Ok is the material point on the mobile coordinate system of the joint between body k and its parent, L(k). This is expressed as follows:

ur

ur

ur

uuuuuur

  =   +
    

(9)

ur

The angular velocity of body k with respect to the ground  can be expressed as the angular velocity of its parent, plus the contribution of the joints linking body k and its parent, L(k). This is expressed as follows:

ur

ur

ur

  =      +      

(10)

ur

Similarly,    can be expressed using point Rk , which is the reference coordinate system of the joint between body k and its parent, L(k). Note that Rk is a material point on body L(k). This is expressed as follows:

ur

ur

ur

uuuuuur

ur

  !» =   !» +  #  $ !»     +   ! #  $ ur

where

% & ( ‘ ) & * is the joint relative velocity, i.e. the translational velocity between body k and its parent,

L(k).

258

(11)

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Rigid Dynamics Analysis

uuuuuur It is important to realize that the vector




ur

has an angular velocity of

      . Joints can have

translational degrees of freedom, and rotational degrees of freedom. The translation is expressed in the reference coordinate system, while the rotation center is the moving coordinate system. In other words, the joint translation is applied first, and the rotation is applied after the coordinate system is updated with the results of the joint translation. The decomposition of the Model Topology graph into a tree results in an oriented parent-child relationship. When the joint has both translational and rotational degrees of freedom and its reference coordinate system is on the child side, the joint must be split into a rotational joint linked to the parent side, and a translational joint linked to the child side, with a fictitious mass-less body between these two joints. While this is an internal representation of that “reverted” joint (i.e., a joint that has both translational and rotational degrees of freedom and a link to the ground on the mobile coordinate system side), results are reported on the original user-defined joint. Because Rk is a material point of body L(k), the same methodology can be used to decompose the velocity into the contribution of the parent joint located between L(k) and L(L(k)) and the contribution of the parent. Two important quantities have been introduced in this process:

ur

•

    is the joint contribution to the angular velocity of body k. ur

•

       is the joint contribution to the translational velocity of point Mk

The concept of recursive calculation of the generalized velocities has also been introduced. The generalized velocities on body k can be computed by adding the contribution of the parent joint to the generalized velocities of body L(k). The contribution of each joint in the chain between body k and the ground can be found and expressed as:

   = ∑    ur ur   !» = ∑   ur

ur

(12) (13)

ur

Vector # $, which is associated with the kinematic variable qi, is the “partial velocity” of the variable expressed at point Mk. It is configuration dependent, i.e., it varies with the geometric variables of the joints located between body k and the ground. The translational and accelerations can similarly be derived to obtain:

% () ,- = ∑  & +) *’ * + & +) *’*  *   ur

 ur

ur ɺ



. 0 23 = ∑  . 1/ 1 + . 1/1  1   ur ɺ

 ur

urɺ



(14)

(15)

Equations of Motion Many methods are available to derive the equations of motion, such as Newton Euler equations, GibbsAppell equations, and Lagrange equations.

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259

Analysis Types The combination of Gibbs-Appell equations with generalized velocities is often referred to as Kane’s equations [KAN61]. Kane’s equations are used for this example.

Open Loop Equations of Motion The positional variation of a point Mk on body k is written as a reduction point using the origin of the body Ok:

uuur

uur

uur

uuuuuur

 =   +     


(16)

Similarly, the translational acceleration of point Mk can be expressed using reduction point Ok:

ur

   =

∑  ur    + ur ɺ    + ∑  ur   + 





urɺ

 uuuuuur

urɺ

      +  



urɺ

uuuuuur

    

(17)

The virtual work of the acceleration can be formed and integrated over body k, and summed over the bodies as follows:

uuur ∑ ∫ ur     

(18)

The integration over the body leads to integrating quantities as follows:

∫ 

uuuuuur



(19)

These terms can be easily pre-calculated as follows:

∫ !&»&

uuuuuur

&

uuuuuur

#$ = $& ! & % &

(20)

In this equation, Mk stands for the mass of body k, and Gk stands for the center of gravity of that body. Other terms lead to:

∫ ‘,(,

uuuuuur

uuuuuur

) ‘ , (, *+

,

(21)

where v is a constant vector. Those terms can be expressed as a function of the inertia tensor of body k. Similarly, the virtual work of external distributed forces is computed as follows:

∫ — 012 ur

uuur

(22)

./ 3

Finally, the open loop equations of motion lead to the following algebraic system:

4 5 =6

(23)

Both the mass matrix M and the force vector F are dependent on the geometric variables and time t. The force vector is also a function of the generalized velocities.

7 8 9

260

: =; 8 : 9

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(24)

Rigid Dynamics Analysis

Closed Loop Equations of Motion When the model has some closed loops, not all joints can be treated as topological joints, thus requiring constraint equations to be added to the system. These constraint equations are usually written in terms of velocities as follows: (25)
 =
 Each kinematic joint generates up to six of these equations, depending on the motion direction that the joint fixes. To be introduced in the equations of motion, a time derivative of these equations must be written as follows:

 

 =  = 

(26)

The equations of motion for the closed loop system become:

 = 

(27)

Subject to:

 

 =   =  

(28)

An additional scalar variable λ (called a Lagrange Multiplier) is introduced for each constraint equation. These constraint equations are introduced in the algebraic system, which then becomes:

  

         =            

(29)

M, B, F, and G can be formed from a set of known geometric variables and kinematic variable values. The above system can be resolved, providing both accelerations qɺ and Lagrange multipliers λ. These Lagrange multipliers can be interpreted as “constraint forces”, i.e., the amount of force needed to prevent motion in the direction of the constraint equations.

Redundant Constraint Equations The system matrix shown in Equation 29 (p. 261) has size n+m where n is the number of degrees of freedom, and m is the number of constraint equations in B. The mass matrix M is usually positive-definite, but the full matrix including the constraint equation will retain that property only if there are no redundant constraint equations in B. The constraint equations are applied to the piston/crankshaft system shown below to demonstrate how the B matrix can contain redundant constraint equations.

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261

Analysis Types Figure 7: Crankshaft Mechanism

The revolute joint between point P1 on body 1 and point P2 on body 2 generates five constraint equations. For the sake of simplicity, these equations are written below in the global coordinate system, even if it is not always possible in general cases. The equations are: 1. 2. 3.

ur

 −

ur

ur

=



ur

 − 

ur

ur

ur

ur

ur

=

−



 =

ur

ur

4.

 − 

ur

ur

ur

5.

 − 

ur

 = =

These equations must be projected on the degrees of freedom. This is achieved in the code by writing the shape functions on each body on points P1 and P2:

ur

ur

ur uuuuur

  =    +  

ur

 

ur

! $ = «$ #

(30) (31)

and:

ur uuuuur

ur

% * = &+ ‘ ,

ur

(32)

(+)+

ur

— 0 = .0 /

(33)

Replacing the velocities in the five constraint equations leads to: 1. 1 7 + 273 74562 7 = 283845628 2. 9>: >;<=9 > = 9?:?;<=9? 3.

262

=

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Rigid Dynamics Analysis 4.

=

5.

=

The five equations above only generate two nontrivial constraints. The third equation indicates that the mechanism cannot shift along the z axis. It also indicates that the mechanism cannot be assembled if the z-coordinate of O2 and O2 are not the same. Similarly, the fourth and fifth equations indicate that the orientation of the axis of the revolute joint in P1/P2 is already entirely dependent on the axis of the two other revolute joints. A manufacturing error in the parallelism of the axis would result in a model that cannot be assembled. As such, this system is redundant. Because introducing the five equations into Equation 29 (p. 261) would make the system matrix singular, some processing must be done on the full set of equations to find a consistent set of equations. Equations that are trivial need to be removed, as well as equations that are colinear. An orthogonalization technique is used to form a new set of equations that keep the matrix invertible. The matrix is decomposed into two orthogonal matrices, Bf and R:

= 

 

(34)

where the [Bf] matrix has a full rank and [R] is a projection matrix . This matrix can then used in Equation 29 (p. 261):

   

 



    

 

   =   

   

(35)

Joint Forces Calculation A benefit of using Kane’s equations and relative parameters is that joint forces in topological joints are eliminated from the algebraic system. Joint forces can be calculated explicitly by writing the dynamic equilibrium of each body recursively, starting from the leaves of the tree associated with the connection graph, with the unknown being the body parent joint’s forces and torque. When the system has redundancies, i.e., the [B] matrix does not have a full rank, some forces cannot be calculated. In the crankshaft example, no information is available in the forces developing in the revolute joint in P1/P2 in the z direction, and the moments cannot be calculated in this joint. These values will be reported as zero, but it is recommended that you avoid such situations by releasing some of the degrees of freedom in the system.

Time Integration Equation 8 (p. 256) provides a relation between generalized accelerations {q}.

and generalized velocities

Equation 8 (p. 256) provides a relation between generalized velocities {q} and the time derivatives of the geometry variables gɺ These two sets of equations form a system of first order explicit ordinary differential equations (ODE).

h =i h j

(36)

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Analysis Types

RK4 Method The fourth order method is based on four estimations. Given an initial value y at time value t, and a time step value dt, the following four estimations are formed:

=



(37)

      +     

 =   +  +     =    +

  =   +     +  A fourth order approximation of y(t+dt) is given by: ɺ    +  ≃  +  +  +   +  

(38) (39) (40)

(41)

RK5 Method The fifth order method is based on six estimations. This method was introduced by Cash and Karp [CAS90]

Adaptive Time Stepping Time step dt must be chosen carefully for the integration of the ODEs to ensure that it is stable (i.e., not becoming exponentially large), and accurate (i.e. the difference between the approximation of the solution and the exact solution is controlled). Both RK4 and RK5 are conditionally stable, meaning that stability can be guaranteed if the time step is small enough. While both algorithms are accurate when they are stable, the time step chosen must be large enough to maintain computational efficiency. For both integration schemes, quantifying the amount of kinetic energy contained in the highest order term of the polynomial approximation can give a good indication of whether the time step should be reduced or increased. If the energy in this high order term is too large, it is likely that the approximation is inaccurate, and the time step should be made smaller. If this energy is significant and controlled, the time step can be accepted, but the time step to be used will be smaller. If the energy is low, then the next time step can be increased. Rigid body systems usually have relatively slow motion, but the following factors can lead to smaller time steps: • Existence of stiff springs and bushing in the model • Three-dimensional rotations • Proximity to geometrically singular configurations, such as the top dead center position of a piston/crankshaft mechanism 264

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Rigid Dynamics Analysis These factors imply that the optimal time step varies with the system velocities and configuration, and thus cannot be determined before running the solution. As a consequence, automatic time stepping generally should not be turned off. When automatic time stepping is used, the energy balance of the system is maintained within the tolerance that is requested. Note that impacts and shock can be non-conservative, and thus will affect the energy balance. This loss during impact is detailed in Contact and Stops (p. 266).

Geometric Correction and Stabilization Using relative parameters, the majority of joints are introduced in the system using their natural degrees of freedom. As a consequence, no matter how big the variation of the degrees of freedom is over the time step, these joints only allow motions that are consistent with the joint kinematics. For example, a revolute joint that has one single rotational degree of freedom can have an increment with a rotation of 3600 degrees in one time step, and it will still not generate out of plane motion, nor will the two points linked by the joint separate. Conversely, some joints are constraint equation based (all the graph closed-loop joints) and need special attention to satisfying proper joint kinematics. The time integration schemes that are used provide a 4th or 5th order polynomial approximation of the solution. These schemes realize a polynomial approximation of the solution. The constraint equations such as those developed in the crankshaft example shown in Figure 7: Crankshaft Mechanism (p. 262) are not polynomial expressions of the geometric variables. Similarly the relation between kinematic

ɺ

ur

variables and geometric variables, expressed as =
 , is usually not polynomial. As a consequence, the constraint equations that are exactly satisfied in terms of accelerations at each of the Runge-Kutta estimations might not be satisfied in terms of velocities and positions at the end of the time step. After a number of time steps, closed loops will not be closed anymore, and points P1 and P2 in the crankshaft example will slowly drift away from each other. To avoid these violations of constraint equations, various strategies can be used. The method known as Baumgarte stabilization [BAU72] introduces additional correction terms in the constraint equation that will be proportional to the current violation of the constraints. For constraint equations that are expressed in terms of velocities, the following is used:

 

 =

(42)

The constraint equation in acceleration become:



=  +  

(43)

For constraint equations expressed in terms of positions, the constraint equation becomes:

 

 =    +  +  

(44)

where the subscript p represents the position violation and the subscript v stands for the velocity violation. Careful selection of and results in stabilization of the drift. Another option proposed by Dehombreux [DEH95] is to project back the solution of the constraint equation. Both positions and velocities can be projected back using this correction.

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265

Analysis Types By projecting the solution, an increment of the geometry variables can be found iteratively:

 =   =    =  + 

(45) (46) (47)

Note that the relation between the kinematic variables and the geometric variables is reused in an incremental form. Because of the dependency of the constraint equations on the geometric variables, this solution is nonlinear, and must be performed until the increment δg is small enough. Once the position has been corrected, another step can be done to correct velocities:

h i j =kl m = m + nm

(48) (49)

As these equations are not velocity dependant, there is no need to iterate on this system.

Contact and Stops So far, the only interaction between bodies that has been considered was permanent joints; however, impacts and contacts will also play a significant role.

Contact Formulation Two bodies will impact when their distance is equal to zero. Once the distance is equal to zero and the bodies are touching, forces can develop in the contact. When the contact distance is greater than zero, there is no interaction between the bodies. Introducing interaction in the equations of motion results in the addition of inequalities to the system:

ot p

q ≥ rt p s

where the subscript u stands for “unilateral”. Unilateral constraints can be introduced in the equations of motion using some highly nonlinear nonpenetration forces. At every configuration, the penetration is computed and a reaction force is applied. This force is equal to zero if the penetration is negative. Force increases rapidly when the penetration is positive. This method simply requires the computation of the penetration, making it very easy to implement.

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(50)

Rigid Dynamics Analysis This force can increase in a linear or non-linear fashion with respect to the penetration. When force increase is linear, it is referred to as contact stiffness. Increasing this force sharply will limit penetrations, and is required for solution accuracy; however, it also has a strong influence on time step stability because it introduces high frequencies in the system. It also introduces pseudo-deformation of the bodies, even though bodies are assumed to be rigid in the equations of motion. A second method of contact formulation is to detect the transition between the separated space of a given pair of bodies and the configuration where they are overlapping. The image below depicts a point mass approaching a separate wall, and the overlapping configuration following impact.

Determining the time of the transition using this point mass model involves advancing in time without introducing non-penetration constraint equations, and realizing at the end of the time step that the penetration is not acceptable. By using the polynomial interpolation that the time integration scheme provides over the time step, the moment where the penetration reaches zero can be found fairly accurately. This time value can be expressed as a fraction of the time step. To determine this time value, find α such that p(t+α∆t)=0 where p is the penetration distance.

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267

Analysis Types

Advancing in time up to α∆t will position the system exactly at the impact time and position, where an impact occurs between the bodies. This impact is assumed to have a very short duration, orders of magnitude smaller than the simulation time. During the impact, the interaction forces between the bodies are first increasing in a compression phase, and then decreasing in the expansion phase until they vanish entirely. This impact will lead to a certain amount of energy loss determined by the material of the bodies interacting. Newton’s impact laws are idealized in this impact process. They relate the relative velocity before the impact to the “bouncing” velocity after the impact using a restitution factor. This restitution factor varies from zero to one. A restitution factor of one indicates that the normal velocity after the impact is equal to the velocity before the impact. + − (51)

=−

Where the superscript + represents quantities after the impact, and the superscript – represents quantities before the impact. A restitution of zero leads to: +
=

(52)

And the general formula will be: + −  − = − +  −

(53)

where r is the restitution factor. This equation is written as a scalar equation at the impact point. Combined with the conservation of momentum it leads to the following system: M(g,t){∆q}={0} B(q){∆q}=0 for all permanent equations and active contacts, and B(q){∆q}=–(1+r)v– for the impacting contact.

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Rigid Dynamics Analysis Each impact with a restitution factor less than one will introduce an energy loss in the system. In a model with multiple imperfect impacts over time, the total energy will be constant piecewise with a drop at each impact.

Contact Kinematics The figure below depicts the contact between convex bodies j and k. Figure 8: Contact Between Two Convex Bodies

Body j Mj

n

Mk Body k

The non-penetration equation below describes the contact between these bodies, and is written along the shared normal at the contact point:

uuuuur uuuuur 

  ur −   =    

(54)

In this equation, the two points Mj and Mk are the points that minimize the distance between the two bodies, and thus are not material points, i.e., their location varies over the bodies with time. For more information on the definition of the contact point, refer to Pfeiffer [PFE96] in References (p. 272).

Special Cases Some special cases are worth mentioning. For instance, when contact occurs in a joint between two bodies linked by that joint, the contact points become material points, and Equation 54 (p. 269) can become dependent on one single degree of freedom. Figure 9: Stops on a Translational Joint (p. 270) shows an example of stop on a translational joint. Both left and right vertical surfaces can impact the red body, but this translates very easily into a simple double inequality:

 ≤ ≤

(55)

where subscript m stands for the minimum bound, and M stands for the maximum bound. The normal here is replaced by the projection on the joint degree of freedom.

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Analysis Types Figure 9: Stops on a Translational Joint

Another case of specialized contact geometry is the radial gap where contact points can be computed explicitly. In the general case of complex geometries, the strategy for computing the contact points and the impact times is more complex.

General Cases In general cases, geometries that are potentially in contact are neither simple nor convex. It is however required to find the accurate position of the contact points between two bodies. Sometimes the contact point is unique, as shown in the figure below. Figure 10: One Contact Point

But for the same pair, the contact can occur in more than one point, as shown in the figure below.

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Rigid Dynamics Analysis Figure 11: Two Contact Points

Finally, the contact can exist along a full line for some geometries, or even on an entire surface, as shown in the figure below. In this case, there is an infinite number of contact points. Figure 12: Cylinder/Cylinder Contact

To control the density of contact points that will need to be adjusted, a surface mesh is used on the bodies that has contact defined. Mesh based contact points are first computed, and these discrete points are then adjusted on the actual geometrical surfaces. It is important to understand that contact will create constraints between the two bodies. The relative motion between these two bodies varies in a 6-dimensional space, so 6 contact points at most will be used to constrain the relative motion of two bodies. These constraints will be added to already existing constraint, so contact can create additional redundancies. For example, two cams with parallel axis will contact along a line (as shown in the figure below). However, if the two axes are maintained parallel by existing joints in the model, one single point through the thickness of the cam is necessary to properly represent the kinematics of the assembly. To avoid useless calculation, the mesh through the thickness can be coarse.

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Analysis Types Figure 13: Contact Requiring One Single Point

If the mesh is very refined, many points through thickness can satisfy the contact equations. An automatic filtering of the contact points will also be performed, but the position of the points through thickness might vary from one step to the next. This can cause some unexpected changes in the moment developed in the contact. To avoid this situation, it can be useful to modify the joints or the geometry itself, and include a draft angle in the cam profile extrusion for force the contact along a line.

References 1. [BAU72] J. Baumgarte, “Stabilization of constraints and integrals of motion in dynamical systems”, Comp. Math. Appl. Mech. Eng. 1, 1972, p. 1-16 2. [CAS90] J. R. Cash, A. H. Karp, «A variable order Runge-Kutta method for initial value problems with rapidly varying right-hand sides», ACM Transactions on Mathematical Software, 1990, Vol 16, p.201-222 3. [DEH95] P. Dehombreux, “Simulation Dynamique des systemes multicorps constraints”, These de Doctorat, Faculte Polytechnique de Mons 4. [PFE96] F. Pfeiffer, C. Glocker, “Multibody Dynamics with Unilateral Contacts”, Wiley, New. York, 1996. 5. [KAN61] Kane, T.R., Dynamics of nonholonomic systems, Transactions of the ASME, J. App. Mech., 1961, Vol. 28, December, p.574-578 6. [WIT77] Wittenburg, J., Dynamics of Systems of Rigid Bodies. Stuttgart. B. G. Teubner. 1977.

Static Structural Analysis Introduction A static structural analysis determines the displacements, stresses, strains, and forces in structures or components caused by loads that do not induce significant inertia and damping effects. Steady loading and response conditions are assumed; that is, the loads and the structure’s response are assumed to vary slowly with respect to time. A static structural load can be performed using the ANSYS or Samcef solver. The types of loading that can be applied in a static analysis include: • Externally applied forces and pressures

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Static Structural Analysis • Steady-state inertial forces (such as gravity or rotational velocity) • Imposed (nonzero) displacements • Temperatures (for thermal strain)

Point to Remember A static structural analysis can be either linear or nonlinear. All types of nonlinearities are allowed large deformations, plasticity, stress stiffening, contact (gap) elements, hyperelasticity and so on. This chapter focuses on linear static analyses, with brief references to nonlinearities. Details of how to handle nonlinearities are described in Nonlinear Controls (p. 655). Note that available nonlinearities can differ from one solver to another.

Preparing the Analysis Create Analysis System Basic general information about this topic … for this analysis type: From the Toolbox, drag a Static Structural or Static Structural (Samcef) template to the Project Schematic. Define Engineering Data Basic general information about this topic … for this analysis type: Material properties can be linear or nonlinear, isotropic or orthotropic, and constant or temperature-dependent. You must define stiffness in some form (for example, Young’s modulus, hyperelastic coefficients, and so on). For inertial loads (such as Standard Earth Gravity), you must define the data required for mass calculations, such as density. Attach Geometry Basic general information about this topic … for this analysis type: When 2D geometry is used, Generalized Plane Strain is not supported for the Samcef solver. Define Part Behavior Basic general information about this topic … for this analysis type: You can define a Point Mass for this analysis type.

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Analysis Types A “rigid” part is essentially a point mass connected to the rest of the structure via joints. Hence in a static structural analysis the only applicable loads on a rigid part are acceleration and rotational velocity loads. You can also apply loads to a rigid part via joint loads. The output from a rigid part is the overall motion of the part plus any force transferred via that part to the rest of the structure. Rigid behavior cannot be used with the Samcef solver. If your model includes nonlinearities such as large deflection or hyperelasticity, the solution time can be significant due to the iterative solution procedure. Hence you may want to simplify your model if possible. For example you may be able to represent your 3D structure as a 2-D plane stress, plane strain, or axisymmetric model or you may be able to reduce your model size through the use of symmetry or antisymmetry surfaces. Similarly if you can omit nonlinear behavior in one or more parts of your assembly without affecting results in critical regions it will be advantageous to do so. Define Connections Basic general information about this topic … for this analysis type: Contact, joints, springs, beams, mesh connections, and end releases are all valid in a static structural analysis. For the Samcef solver, only contacts, springs, and beams are supported. Joints are not supported. Apply Mesh Controls/Preview Mesh Basic general information about this topic … for this analysis type: Provide an adequate mesh density on contact surfaces to allow contact stresses to be distributed in a smooth fashion. Likewise, provide a mesh density adequate for resolving stresses; areas where stresses or strains are of interest require a relatively fine mesh compared to that needed for displacement or nonlinearity resolution. If you want to include nonlinearities, the mesh should be able to capture the effects of the nonlinearities. For example, plasticity requires a reasonable integration point density (and therefore a fine element mesh) in areas with high plastic deformation gradients. Establish Analysis Settings Basic general information about this topic … for this analysis type: For simple linear static analyses you typically do not need to change these settings. For more complex analyses the basic controls are: Large Deflection (p. 642) is typically needed for slender structures. A rule of thumb is that you can use large deflection if the transverse displacements in a slender structure are more than 10% of the thickness.

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Static Structural Analysis Small deflection and small strain analyses assume that displacements are small enough that the resulting stiffness changes are insignificant. Setting Large Deflection to On will take into account stiffness changes resulting from changes in element shape and orientation due to large deflection, large rotation, and large strain. Therefore the results will be more accurate. However this effect requires an iterative solution. In addition it may also need the load to be applied in small increments. Therefore, the solution may take longer to solve. You also need to turn on large deflection if you suspect instability (buckling) in the system. Use of hyperelastic materials also requires large deflection to be turned on. Step Controls (p. 635) are used to i) control the time step size and other solution controls and ii) create multiple steps when needed. Typically analyses that include nonlinearities such as large deflection or plasticity require control over time step sizes as outlined in the Automatic Time Stepping (p. 668) section. Multiple steps are required for activation/deactivation of displacement loads or pretension bolt loads. This group can be modified on a per step basis.

Note Time Stepping is available for any solver. Output Controls (p. 658) allow you to specify the time points at which results should be available for postprocessing. In a nonlinear analysis it may be necessary to perform many solutions at intermediate load values. However i) you may not be interested in all the intermediate results and ii) writing all the results can make the results file size unwieldy. This group can be modified on a per step basis except for Stress and Strain. Nonlinear Controls (p. 655) allow you to modify convergence criteria and other specialized solution controls. Typically you will not need to change the default values for this control. This group can be modified on a per step basis. If you are performing a nonlinear Static Structural analysis, the Newton-Raphson Type property becomes available. This property only affects nonlinear analyses. Your selections execute the MAPDL NROPT command. The default option, Program Controlled, allows the application to select the appropriate NROPT option or you can make a manual selection and choose Full, Modified, or Unsymmetric. See the Help section for the NROPT command in the Mechanical APDL Command Reference for additional information about the operation of the Newton-Raphson Type property. Analysis Data Management (p. 664) settings enable you to save specific solution files from the Static Structural analysis for use in other analyses. You can set the Future Analysis field to Pre-Stressed Analysis if you intend to use the static structural results in a subsequent Harmonic Response, Modal, or Linear Buckling (Linear Buckling is applicable to Static Structural systems only) analysis. If you link a structural system to another analysis type in advance, the Future Analysis field defaults to Pre-Stressed Analysis. A typical example is the large tensile stress induced in a turbine blade under centrifugal load. This causes significant stiffening of the blade resulting in much higher,

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Analysis Types realistic natural frequencies in a modal analysis. More details are available in the section Define Initial Conditions (p. 136).

Note Scratch Solver Files, Save ANSYS db, Solver Units, and Solver Unit System are applicable to Static Structural systems only. Define Initial Conditions Basic general information about this topic … for this analysis type: Initial condition is not applicable for Static Structural analyses. Apply Loads and Supports Basic general information about this topic … for this analysis type: For a static structural analysis applicable loads are all inertial, structural, imported, and interaction loads, and applicable supports are all structural supports. For the Samcef solver, the following loads and supports are not available: Hydrostatic Pressure, Bearing Load, Bolt Pretension, Joint Load, Fluid Solid Interface, Motion Loads, Compression Only Support, Elastic Support. Loads and supports vary as a function of time even in a static analysis as explained in the Role of Time in Tracking (p. 667). In a static analysis, the load’s magnitude could be a constant value or could vary with time as defined in a table or via a function. Details of how to apply a tabular or function load are described in Defining Boundary Condition Magnitude (p. 848). In addition, see the Apply Loads and Supports section for more information about time stepping and ramped loads.

Note A static analysis can be followed by a “pre-stressed” analysis such as modal or linear (eigenvalue) buckling analysis. In this subsequent analysis the effect of stress on stiffness of the structure (stress-stiffness effect) is taken into account. If the static analysis has a pressure or force load applied on faces (3D) or edges (2D) this could result in an additional stiffness contribution called “pressure load stiffness” effect. This effect plays a significant role in linear (eigenvalue) buckling analyses. This additional effect is computed during the eigen analysis using the pressure or force value calculated at the time in the static analysis from which the perturbation occurs. See the Applying Pre-Stress Effects section for more information on this topic. When using the Samcef solver, Direct FE boundary conditions are not available. Solve

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Steady-State Thermal Analysis Basic general information about this topic … for this analysis type: When performing a nonlinear analysis you may encounter convergence difficulties due to a number of reasons. Some examples may be initially open contact surfaces causing rigid body motion, large load increments causing non-convergence, material instabilities, or large deformations causing mesh distortion that result in element shape errors. To identify possible problem areas some tools are available under Solution Information object Details view. Solution Output continuously updates any listing output from the solver and provides valuable information on the behavior of the structure during the analysis. Any convergence data output in this printout can be graphically displayed as explained in the Solution Information section. You can display contour plots of Newton-Raphson Residuals in a nonlinear static analysis. Such a capability can be useful when you experience convergence difficulties in the middle of a step, where the model has a large number of contact surfaces and other nonlinearities. When the solution diverges identifying regions of high Newton-Raphson residual forces can provide insight into possible problems. Result Tracker (applicable to Static Structural systems only) is another useful tool that allows you to monitor displacement and energy results as the solution progresses. This is especially useful in case of structures that possibly go through convergence difficulties due to buckling instability. Result Tracker is not available to the Samcef solver. Review Results Basic general information about this topic … for this analysis type: All structural result types except frequencies are available as a result of a static structural analysis. You can use a Solution Information object to track, monitor, or diagnose problems that arise during a solution. Once a solution is available you can contour the results or animate the results to review the response of the structure. As a result of a nonlinear static analysis you may have a solution at several time points. You can use probes to display the variation of a result item as the load increases. An example might be large deformation analyses that result in buckling of the structure. In these cases it is also of interest to plot one result quantity (for example, displacement at a vertex) against another results item (for example, applied load). You can use the Charts feature to develop such charts.

Steady-State Thermal Analysis Introduction You can use a steady-state thermal analysis to determine temperatures, thermal gradients, heat flow rates, and heat fluxes in an object that are caused by thermal loads that do not vary over time. A steadyRelease 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types state thermal analysis calculates the effects of steady thermal loads on a system or component. Engineers often perform a steady-state analysis before performing a transient thermal analysis, to help establish initial conditions. A steady-state analysis also can be the last step of a transient thermal analysis, performed after all transient effects have diminished. A steady-state thermal analysis can be performed using the

Point to Remember A steady-state thermal analysis may be either linear, with constant material properties; or nonlinear, with material properties that depend on temperature. The thermal properties of most material do vary with temperature, so the analysis usually is nonlinear. Including radiation effects or temperature dependent convection coefficient also makes the analysis nonlinear.

Preparing the Analysis Create Analysis System Basic general information about this topic … for this analysis type: From the Toolbox, drag a Steady-State Thermal or Steady-State Thermal (Samcef) template to the Project Schematic. Define Engineering Data Basic general information about this topic … for this analysis type: Thermal Conductivity must be defined for a steady-state thermal analysis. Thermal Conductivity can be isotropic or orthotropic, and constant or temperature-dependent. Attach Geometry Basic general information about this topic … for this analysis type: There are no specific considerations for a steady-state thermal analysis. Define Part Behavior Basic general information about this topic … for this analysis type: There are no specific considerations for a steady-state thermal analysis. Define Connections Basic general information about this topic

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Steady-State Thermal Analysis … for this analysis type: In a thermal analysis only contact is valid. Any joints or springs are ignored. With contact the initial status is maintained throughout the thermal analysis, that is, any closed contact faces will remain closed and any open contact faces will remain open for the duration of the thermal analysis. Heat conduction across a closed contact face is set to a sufficiently high enough value (based on the thermal conductivities and the model size) to model perfect contact with minimal thermal resistance. If needed, you can model imperfect contact by manually inputting a Thermal Conductance value. By default, Contact Results (accessible through User Defined Results via CONTSTAT or CONTFLUX – see the User Defined Results for the Mechanical APDL Solver section.) are not written to the result file in a thermal analysis. To write them, issue the RSTSUPPRESS,NONE command via a Command object at the /SOLU level. Apply Mesh Controls/Preview Mesh Basic general information about this topic … for this analysis type: There are no specific considerations for steady-state thermal analysis itself. However if the temperatures from this analysis are to be used in a subsequent structural analysis the mesh must be identical. Therefore in this case you may want to make sure the mesh is fine enough for structural analysis. Establish Analysis Settings Basic general information about this topic … for this analysis type: For a steady-state thermal analyses you typically do not need to change these settings. The basic controls are: Step Controls (p. 635) allow you to control the rate of loading which could be important in a steady-state thermal analysis if the material properties vary rapidly with temperature. When such nonlinearities are present it may be necessary to apply the loads in small increments and perform solutions at these intermediate loads to achieve convergence. You may wish to use multiple steps if you a) want to analyze several different loading scenarios within the same analysis or b) if you want to change the analysis settings such as the time step size or the solution output frequency over specific time ranges. Output Controls (p. 658) allow you to specify the time points at which results should be available for postprocessing. In a nonlinear analysis it may be necessary to perform many solutions at intermediate load values. However i) you may not be interested in all the intermediate results and ii) writing all the results can make the results file size unwieldy. In this case you can restrict the amount of output by requesting results only at certain time points. Nonlinear Controls (p. 655) allow you to modify convergence criteria and other specialized solution controls. Typically you will not need to change the default values for this control.

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Analysis Types Nonlinear Controls are exposed for the ANSYS solver only. Analysis Data Management (p. 664) settings enable you to save specific solution files from the steady-state thermal analysis for use in other analyses. Define Initial Conditions Basic general information about this topic … for this analysis type: For a steady-state thermal analysis you can specify an initial temperature value. This uniform temperature is used during the first iteration of a solution as follows: • To evaluate temperature-dependent material properties. • As the starting temperature value for constant temperature loads. Apply Loads and Supports Basic general information about this topic … for this analysis type: The following loads are supported in a steady-state thermal analysis: • Temperature (p. 747) • Convection (p. 749) • Radiation (p. 753) • Heat Flow (p. 757) • Perfectly Insulated (p. 757) • Heat Flux (p. 759) • Internal Heat Generation (p. 762) • Imported Temperature (p. 846) • Imported Convection Coefficient (p. 840) • Fluid Solid Interface (p. 782) Loads and supports vary as a function of time even in a static analysis as explained in the Role of Time in Role of Time in Tracking (p. 667). In a static analysis, the load’s magnitude could be a constant value or could vary with time as defined in a table or via a function. Details of how to apply a tabular or function load are described in Defining Boundary Condition Magnitude (p. 848). In addition, see the Apply Loads and Supports section for more information about time stepping and ramped loads. Fluid Solid Interface (p. 782) is not available for the Samcef solver. Solve 280

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Thermal-Electric Analysis Basic general information about this topic … for this analysis type: The Solution Information object provides some tools to monitor solution progress. Solution Output continuously updates any listing output from the solver and provides valuable information on the behavior of the structure during the analysis. Any convergence data output in this printout can be graphically displayed as explained in the Solution Information section. You can also insert a Result Tracker object under Solution Information. This tool allows you to monitor temperature at a vertex as the solution progresses. Result Tracker is not available to the Samcef solver. Review Results Basic general information about this topic … for this analysis type: Applicable results are all thermal result types. Once a solution is available you can contour the results or animate the results to review the response of the structure. As a result of a nonlinear analysis you may have a solution at several time points. You can use probes to display the variation of a result item over the load history. Also of interest is the ability to plot one result quantity (for example, maximum temperature on a face) against another results item (for example, applied heat generation rate). You can use the Charts feature to develop such charts. Note that Charts are also useful to compare results between two analyses of the same model.

Thermal-Electric Analysis Introduction A Steady-State Thermal-Electric Conduction analysis allows for a simultaneous solution of thermal and electric fields. This coupled-field capability models joule heating for resistive materials and contact electric conductance as well as Seebeck, Peltier, and Thomson effects for thermoelectricity, as described below. • Joule heating — Heating occurs in a resistive conductor carrying an electric current. Joule heating is proportional to the square of the current, and is independent of the current direction. Joule heating is also present and accounted for at the contact interface between bodies in inverse proportion to the contact electric conductance properties. (Note however that the Joule Heat results object will not display contact joule heating values. Only solid body joule heating is represented). • Seebeck effect — A voltage (Seebeck EMF) is produced in a thermoelectric material by a temperature difference. The induced voltage is proportional to the temperature difference. The proportionality coefficient is know as the Seebeck Coefficient (α). Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types • Peltier effect — Cooling or heating occurs at a junction of two dissimilar thermoelectric materials when an electric current flows through that junction. Peltier heat is proportional to the current, and changes sign if the current direction is reversed. • Thomson effect — Heat is absorbed or released in a non-uniformly heated thermoelectric material when electric current flows through it. Thomson heat is proportional to the current, and changes sign if the current direction is reversed.

Points to Remember Electric loads may be applied to parts with electric properties and thermal loads may be applied to bodies with thermal properties. Parts with both physics properties can support both thermal and electric loads. See the Steady-State Thermal Analysis section and the Electric Analysis section of the help for more information about applicable loads, boundary conditions, and results types. In addition to calculating the effects of steady thermal and electric loads on a system or component, a Steady-State Thermal-Electric analysis supports a multi-step solution.

Preparing the Analysis Create Analysis System Basic general information about this topic … for this analysis type: From the Toolbox, drag the Thermal-Electric template to the Project Schematic. Define Engineering Data Basic general information about this topic … for this analysis type: To have Thermal and/or Electrical effects properly applied to the parts of your model, you need to define the appropriate material properties. For a steady-state analysis, the electrical property Resistivity is required for Joule Heating effects and Thermal Conductivity for thermal conduction effects. Seebeck/Peltier/Thomson effects require you to define the Seebeck Coefficient material property. Attach Geometry Basic general information about this topic … for this analysis type: Note that 3D shell bodies and line bodies are not supported in a thermal-electric analysis. Define Part Behavior Basic general information about this topic … for this analysis type:

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Thermal-Electric Analysis There are no specific considerations for a thermal-electric analysis. Define Connections Basic general information about this topic … for this analysis type: Contact across parts during a thermal-electric analysis consider thermal and/or electric effects based on the material properties of adjacent parts. That is, if both parts have thermal properties, thermal contact is applied and if both parts have electric properties, electric contact is applied. Apply Mesh Controls/Preview Mesh Basic general information about this topic … for this analysis type: There are no specific considerations regarding meshing for a thermal-electric analysis. Establish Analysis Settings Basic general information about this topic … for this analysis type: For a thermal-electric analysis, the basic controls are: Step Controls (p. 635): used to specify the end time of a step in a single or multiple step analysis. Multiple steps are needed if you want to change load values, the solution settings, or the solution output frequency over specific steps. Typically you do not need to change the default values. Typical thermal-electric problems contain temperature dependent material properties and are therefore nonlinear. Nonlinear Controls for both thermal and electrical effects are available and include Heat and Temperature convergence for thermal effects and Voltage and Current convergence for electric effects. Output Controls (p. 658) allow you to specify the time points at which results should be available for postprocessing. A multi-step analysis involves calculating solutions at several time points in the load history. However you may not be interested in all of the possible results items and writing all the results can make the result file size unwieldy. You can restrict the amount of output by requesting results only at certain time points or limit the results that go onto the results file at each time point. Analysis Data Management (p. 664) settings. The default Solver Controls setting for thermal-electric analysis is the Direct (Sparse) solver. The Iterative (PCG) solver may be selected as an alternative solver. If Seebeck effects are included, the solver is automatically set to Direct. Define Initial Conditions

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Analysis Types Basic general information about this topic … for this analysis type: There is no initial condition specification for a thermal-electric analysis. Apply Loads and Supports Basic general information about this topic … for this analysis type: The following loads are supported in a Thermal-Electric analysis: • Voltage • Current • Coupling Condition • Temperature • Convection • Radiation • Heat Flow • Perfectly Insulated • Heat Flux • Internal Heat Generation Solve Basic general information about this topic … for this analysis type: The Solution Information object provides some tools to monitor solution progress. Solution Output continuously updates any listing output from the solver and provides valuable information on the behavior of the model during the analysis. Any convergence data output in this printout can be graphically displayed as explained in the Solution Information section. Review Results Basic general information about this topic … for this analysis type: Applicable results include all thermal and electric results.

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Transient Structural Analysis Once a solution is available, you can contour the results or animate the results to review the responses of the model. For the results of a multi-step analysis that has a solution at several time points, you can use probes to display variations of a result item over the steps. You may also wish to use the Charts feature to plot multiple result quantities against time (steps). For example, you could compare current and joule heating. Charts can also be useful when comparing the results between two analysis branches of the same model.

Transient Structural Analysis Introduction A transient analysis, by definition, involves loads that are a function of time. In the Mechanical application, you can perform a transient analysis on either a flexible structure or a rigid assembly. For a flexible structure, the Mechanical application can use the ANSYS Mechanical APDL or the Samcef solver to solve a Transient Structural analysis. You can perform a transient structural analysis (also called time-history analysis) in the Mechanical application using the transient structural analysis that specifically uses the ANSYS Mechanical APDL solver. This type of analysis is used to determine the dynamic response of a structure under the action of any general time-dependent loads. You can use it to determine the time-varying displacements, strains, stresses, and forces in a structure as it responds to any transient loads. The time scale of the loading is such that the inertia or damping effects are considered to be important. If the inertia and damping effects are not important, you might be able to use a static analysis instead.

Points to Remember A transient structural analysis can be either linear or nonlinear. All types of nonlinearities are allowed — large deformations, plasticity, contact, hyperelasticity, and so on. ANSYS Workbench offers an additional solution method of Mode Superposition to perform linear transient structural analysis. In the Mode Superposition method, the transient response to a given loading condition is obtained by calculating the necessary linear combinations of the eigenvectors obtained in a modal analysis. For more details, refer to Transient Structural Analysis Using Linked Modal Analysis System section. The Mode Superposition method is not available to the Samcef solver. A transient dynamic analysis is more involved than a static analysis because it generally requires more computer resources and more of your resources, in terms of the “engineering” time involved. You can save a significant amount of these resources by doing some preliminary work to understand the physics of the problem. For example, you can: 1. Try to understand how nonlinearities (if you are including them) affect the structure’s response by doing a static analysis first. In some cases, nonlinearities need not be included in the dynamic analysis. Including nonlinear effects can be expensive in terms of solution time. 2. Understand the dynamics of the problem. By doing a modal analysis, which calculates the natural frequencies and mode shapes, you can learn how the structure responds when those modes are excited. The natural frequencies are also useful for calculating the correct integration time step.

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Analysis Types 3. Analyze a simpler model first. A model of beams, masses, springs, and dampers can provide good insight into the problem at minimal cost. This simpler model may be all you need to determine the dynamic response of the structure.

Note Refer to the following sections of the Mechanical APDL application documentation for a more thorough treatment of dynamic analysis capabilities: • The Transient Dynamic Analysis chapter of the Structural Analysis Guide — for a technical overview of nonlinear transient dynamics. • The Multibody Analysis Guide — for a reference that is particular to multibody motion problems. In this context, “multibody” refers to multiple rigid or flexible parts interacting in a dynamic fashion. Although not all dynamic analysis features discussed in these manuals are directly applicable to Mechanical features, the manuals provide an excellent background on general theoretical topics.

Preparing a Transient Structural Analysis Create Analysis System Basic general information about this topic … for this analysis type: From the Toolbox, drag a Transient Structural or a Transient Structural (Samcef) template to the Project Schematic. Define Engineering Data Basic general information about this topic … for this analysis type: Material properties can be linear or nonlinear, isotropic or orthotropic, and constant or temperature-dependent. Both Young’s modulus (and stiffness in some form) and density (or mass in some form) must be defined. Attach Geometry Basic general information about this topic … for this analysis type: There are no specific considerations for transient structural analysis. Define Part Behavior Basic general information about this topic

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Transient Structural Analysis … for this analysis type: You can define a Point Mass for this analysis type. In a transient structural analysis, rigid parts are often used to model mechanisms that have gross motion and transfer loads between parts, but detailed stress distribution is not of interest. The output from a rigid part is the overall motion of the part plus any force transferred via that part to the rest of the structure. A “rigid” part is essentially a point mass connected to the rest of the structure via joints. Hence in a transient structural analysis the only applicable loads on a rigid part are acceleration and rotational velocity loads. You can also apply loads to a rigid part via joint loads. Rigid behavior cannot be used with the Samcef solver. If your model includes nonlinearities such as large deflection or hyperelasticity, the solution time can be significant due to the iterative solution procedure. Hence, you may want to simplify your model if possible. For example, you may be able to represent your 3D structure as a 2-D plane stress, plane strain, or axisymmetric model, or you may be able to reduce your model size through the use of symmetry or antisymmetry surfaces. Similarly, if you can omit nonlinear behavior in one or more parts of your assembly without affecting results in critical regions, it will be advantageous to do so. Define Connections Basic general information about this topic … for this analysis type: Contact, joints and springs are all valid in a transient structural analysis. In a transient structural analysis, you can specify a damping coefficient property in longitudinal springs that will generate a damping force proportional to velocity. For the Samcef solver, only contacts, springs, and beams are supported. Joints are not supported. Apply Mesh Controls/Preview Mesh Basic general information about this topic … for this analysis type: Provide an adequate mesh density on contact surfaces to allow contact stresses to be distributed in a smooth fashion. Likewise, provide a mesh density adequate for resolving stresses; areas where stresses or strains are of interest require a relatively fine mesh compared to that needed for displacement or nonlinearity resolution. If you want to include nonlinearities, the mesh should be able to capture the effects of the nonlinearities. For example, plasticity requires a reasonable integration point density (and therefore a fine element mesh) in areas with high plastic deformation gradients. In a dynamic analysis, the mesh should be fine enough to be able to represent the highest mode shape of interest. Establish Analysis Settings Basic general information about this topic Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types … for this analysis type: For transient structural analyses, the basic controls include: Large Deflection (p. 642) is typically needed for slender structures. A rule of thumb is that you can use large deflection if the transverse displacements in a slender structure are more than 10% of the thickness. Small deflection and small strain analyses assume that displacements are small enough that the resulting stiffness changes are insignificant. Setting Large Deflection to On will take into account stiffness changes resulting from change in element shape and orientation due to large deflection, large rotation, and large strain. Therefore the results will be more accurate. However this effect requires an iterative solution. In addition it may also need the load to be applied in small increments. Therefore the solution may take longer to solve. You also need to turn on large deflection if you suspect instability (buckling) in the system. Use of hyperelastic materials also requires large deflection to be turned on. Step Controls (p. 635) allow you to control the time step size in a transient analysis. Refer to the Guidelines for Integration Step Size (p. 669) section for further information. In addition this control also allows you create multiple steps. Multiple steps are useful if new loads are introduced or removed at different times in the load history, or if you want to change the analysis settings such as the time step size at some points in the time history. When the applied load has high frequency content or if nonlinearities are present, it may be necessary to use a small time step size (that is, small load increments) and perform solutions at these intermediate time points to arrive at good quality results. This group can be modified on a per step basis. Output Controls (p. 658) allow you to specify the time points at which results should be available for postprocessing. In a transient nonlinear analysis it may be necessary to perform many solutions at intermediate time values. However, i) you may not be interested in all the intermediate results, and ii) writing all the results can make the results file size unwieldy. This group can be modified on a per step basis except for Stress and Strain. Nonlinear Controls (p. 655) allow you to modify convergence criteria and other specialized solution controls. Typically you will not need to change the default values for this control. This group can be modified on a per step basis. If you are performing a nonlinear Full Transient Structural analysis, the Newton-Raphson Type property becomes available. This property only affects nonlinear analyses. Your selections execute the MAPDL NROPT command. The default option, Program Controlled, allows the application to select the appropriate NROPT option or you can make a manual selection and choose Full, Modified, or Unsymmetric. See the Help section for the NROPT command in the Mechanical APDL Command Reference for additional information about the operation of the Newton-Raphson Type property. Damping Controls (p. 653) allow you to specify damping for the structure in the Transient analysis. Controls include: Stiffness Coefficient (Beta Damping), Mass Coefficient (Alpha Damping), and Numerical Damping. They can also be applied as Material Damping using the Engineering Data tab. In addition, Numerical Damping is also available for handling result accuracy. Damping controls are not available to the Samcef solver.

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Transient Structural Analysis Analysis Data Management (p. 664) settings enable you to save specific solution files from the transient structural analysis for use in other analyses. The default behavior is to only keep the files required for postprocessing. You can use these controls to keep all files created during solution or to create and save the Mechanical APDL application database (db file). Define Initial Conditions Basic general information about this topic … for this analysis type: 1. A transient analysis involves loads that are functions of time. The first step in applying transient loads is to establish initial conditions (that is, the condition at Time = 0). 2. The default initial condition for a transient structural analysis is that the structure is “at rest”, that is, both initial displacement and initial velocity are zero. A transient structural analysis is at rest, by default. The Initial Conditions object allows you to specify Velocity. 3. In many analyses one or more parts will have an initial known velocity such as in a drop test, metal forming analysis or kinematic analysis. In these analyses, you can specify a constant Velocity initial condition if needed. The constant velocity could be scoped to one or more parts of the structure. The remaining parts of the structure which are not part of the scoping will retain the “at rest” initial condition. 4. Initial Condition using Steps (ANSYS solver only): You can also specify initial conditions using step controls, that is, by specifying multiple steps in a transient analysis and controlling the time integration effects along with activation/deactivation of loads (ANSYS solver only). This comes in handy when, for example, you have different parts of your model that have different initial velocities or more complex initial conditions. The following are approaches to some commonly encountered initial condition scenarios: a. Initial Displacement = 0, Initial Velocity ≠ 0 for some parts: The nonzero velocity is established by applying small displacements over a small time interval on the part of the structure where velocity is to be specified. i.

Specify 2 steps in your analysis. The first step will be used to establish initial velocity on one or more parts.

ii. Choose a small end time (compared to the total span of the transient analysis) for the first step. The second step will cover the total time span. iii. Specify displacement(s) on one or more faces of the part(s) that will give you the required initial velocity. This requires that you do not have any other boundary condition on the part that will interfere with rigid body motion of that part. Make sure that these displacements are ramped from a value of 0. iv. Deactivate or release the specified displacement load in the second step so that the part is free to move with the specified initial velocity. For example, if you want to specify an initial Y velocity of 5 inch/second on a part, and your first step end time is 0.001 second, then specify the Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types following loads. Make sure that the load is ramped from a value of 0 at time = 0 so that you will get the required velocity.

In this case the end time of the actual transient analysis is 30 seconds. Note that the Y displacement in the second step is deactivated. v. In the Analysis Settings Details view, set the following for first step:

vi. You can choose appropriate time step sizes for the second step (the actual transient). Make sure that time integration effects are turned on for the second step. In the first step, inertia effects will not be included but velocity will be computed based on the displacement applied. In the second step, this displacement is released by deactivation and the time integration effects are turned on. b. Initial Displacement ≠ 0, Initial Velocity ≠ 0: This is similar to case a. above except that the imposed displacements are the actual values instead of “small” values. For example if the initial displacement is 1 inch and the initial velocity is 2.5 inch/sec then you would apply a displacement of 1 inch over 0.4 seconds. i.

Specify 2 steps in your analysis. The first step will be used to establish initial displacement and velocity on one or more parts.

ii. Choose a small end time (compared to the total span of the transient analysis) for the first step. The second step will cover the total time span. iii. Specify the initial displacement(s) on one or more faces of the part(s) as needed. This requires that you do not have any other boundary condition on the part that will interfere with rigid body motion of that part. Make sure that these displacements are ramped from a value of 0.

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Transient Structural Analysis iv. Deactivate or release the specified displacement load in the second step so that the part is free to move with the specified initial velocity. For example if you want to specify an initial Z velocity on a part of 0.5 inch/sec and have an initial displacement of 0.1 inch, then your first step end time = (0.1/0.5) = 0.2 second. Make sure that the displacement is ramped from a value of 0 at time = 0 so that you will get the required velocity.

In this case the end time of the actual transient analysis is 5 seconds. Note that the Z displacement in the second step is deactivated. v. In the Analysis Settings Details view, set the following for first step:

vi. You can choose appropriate time step sizes for the second step (the actual transient). Make sure that time integration effects are turned on for the second step. In the first step, inertia effects will not be included but velocity will be computed based on the displacement applied. In the second step, this displacement is released by deactivation and the time integration effects are turned on. c. Initial Displacement ≠ 0, Initial Velocity = 0: This requires the use of two steps also. The main difference between b. above and this scenario is that the displacement load in the first step is not ramped from zero. Instead it is step applied as shown below with 2 or more substeps to ensure that the velocity is zero at the end of step 1. i.

Specify 2 steps in your analysis. The first step will be used to establish initial displacement on one or more parts.

ii. Choose an end time for the first step that together with the initial displacement values will create the necessary initial velocity.

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Analysis Types iii. Specify the initial displacement(s) on one or more faces of the part(s) as needed. This requires that you do not have any other boundary condition on the part that will interfere with rigid body motion of that part. Make sure that this load is step applied, that is, apply the full value of displacements at time = 0 itself and maintain it throughout the first step. iv. Deactivate or release the specified displacement load in the second step so that the part is free to move with the initial displacement values. For example if you want to specify an initial Z displacement of 0.1 inch and the end time for the first step is 0.001 seconds, then the load history displays as shown below. Note the step application of the displacement.

In this case the end time of the actual transient analysis is 5 seconds. Note that the Z displacement in the second step is deactivated. v. In the Analysis Settings Details view, set the following for first step. Note that the number of substeps must be at least 2 to set the initial velocity to zero.

vi. You can choose appropriate time step sizes for the second step (the actual transient). Make sure that time integration effects are turned on for the second step. In the first step, inertia effects will not be included but velocity will be computed based on the displacement applied. But since the displacement value is held constant, the velocity will evaluate to zero after the first substep. In the second step, this displacement is released by deactivation and the time integration effects are turned on. Apply Loads and Supports Basic general information about this topic

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Transient Structural Analysis … for this analysis type: For a static structural analysis applicable loads are all inertial, structural loads, imported, and interaction loads, and applicable supports are all structural supports. Joint Loads are used to kinematically drive joints. See the Joint Load (p. 742) section for details. Joint Loads are not available to the Samcef solver. In this analysis, the load’s magnitude could be a constant value or could vary with time as defined in a table or via a function. Details of how to apply a tabular or function load are described in Defining Boundary Condition Magnitude (p. 848). In addition, see the Apply Loads and Supports section for more information about time stepping and ramped loads. For the solver to converge, it is recommended that you ramp joint load angles and positions from zero to the real initial condition over one step. Solve Basic general information about this topic … for this analysis type: When performing a nonlinear analysis, you may encounter convergence difficulties due to a number of reasons. Some examples may be initially open contact surfaces causing rigid body motion, large load increments causing non-convergence, material instabilities, or large deformations causing mesh distortion that result in element shape errors. To identify possible problem areas some tools are available under Solution Information object Details view. Solution Output continuously updates any listing output from the solver and provides valuable information on the behavior of the structure during the analysis. Any convergence data output in this printout can be graphically displayed as explained in the Solution Information section. You can display contour plots of Newton-Raphson Residuals in a nonlinear static analysis. Such a capability can be useful when you experience convergence difficulties in the middle of a step, where the model has a large number of contact surfaces and other nonlinearities. When the solution diverges, identifying regions of high Newton-Raphson residual forces can provide insight into possible problems. Result Tracker is another useful tool that allows you to monitor displacement and energy results as the solution progresses. This is especially useful in the case of structures that may go through convergence difficulties due to buckling instability. Result Tracker is not available to the Samcef solver. Review Results Basic general information about this topic … for this analysis type: All structural result types except frequencies are available as a result of a transient structural analysis. You can use a Solution Information object to track, monitor, or diagnose problems that arise during a solution. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types Once a solution is available you can contour the results or animate the results to review the response of the structure. As a result of a nonlinear static analysis, you may have a solution at several time points. You can use probes to display the variation of a result item as the load increases.

Note Fixed body-to-body joints between two rigid bodies will not produce a joint force or moment in a transient structural analysis. Also of interest is the ability to plot one result quantity (for example, displacement at a vertex) against another result item (for example, applied load). You can use the Charts feature to develop such charts. Charts are also useful to compare results between two analyses of the same model. For example, you can compare the displacement response at a vertex from two transient structural analyses with different damping characteristics.

Transient Structural Analysis Using Linked Modal Analysis System Preparing the Analysis Create Analysis System Basic general information about this topic … for this analysis type: Because this analysis is linked to (or based on) modal responses, a modal analysis is a prerequisite. This linked setup allows the two analysis systems to share resources such as engineering data, geometry, and boundary condition type definitions made in the Modal Analysis. Transient structural analysis with linked modal analysis is not available using the Samcef solver.

Note The Mode Superposition Transient Structural analysis is allowed to be linked to a pre-stressed Modal analysis. From the Toolbox, drag a Modal template to the Project Schematic. Then, drag a Transient Structural template directly onto the Solution cell of Modal template. Establish Analysis Settings Basic general information about this topic … for this analysis type: Step Controls — the analysis is only compatible with constant time stepping. So, auto time stepping is turned off and will always be in read only mode. The user specified substep or time step value is applicable to all the load steps. All of the Step Controls settings applied to this analysis are not step aware. The time integration is turned on

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Transient Structural Analysis Using Linked Modal Analysis System by default and will always be in read-only mode. A Time Step value that results in an integral number of sub steps over the load step must be selected. Options — allow you to turn on the property Include Residual Vectors to execute the RESVEC command and calculate residual vectors. Output Controls — allow you to request Stress, Strain, Nodal Force, and Reaction results to be calculated. To expand reaction forces in the modal solution, set the Nodal Force property to Yes or Constrained Nodes. The General Miscellaneous property needs to be set to Yes in order to apply a Beam Tool and/or to calculate Beam Results. In addition, this setting is required to correctly produce twisted beam shapes. For better performance, you can also choose to have these results expanded from transient or modal solutions. The Contact Miscellaneous option is not available. Damping Controls — allow you to specify Constant Damping Ratio, Mass Coefficient (Alpha Damping), Stiffness Coefficient (Beta Damping), and Numerical Damping for the Mode Superposition (MSUP) Transient analysis. You can also use the Engineering Data tabs to specify damping.

Note For an MSUP Transient analysis, if you define the Solver Type as Reduced Damped and the Store Complex Solution property is set to No, only Constant Damping Ratio is supported to define the damping ratio. The Numerical Damping Value defaults to 0.005 and becomes read-only for this analysis. To edit this value, change the Numerical Damping field to Manual from Program Controlled.

Note Solver Controls, Restart Controls, Nonlinear Controls and Creep Controls are not applicable to the current analysis. Define Initial Conditions Basic general information about this topic … for this analysis type: The Transient Structural analysis must point to a Modal analysis in the Modal (Initial Conditions) object. This object also indicates whether the upstream Modal analysis is pre-stressed. If it is a pre-stress analysis, the name of the pre-stress analysis system is displayed in the Pre-Stress Environment field, otherwise the field indicates None. The Modal Analysis must extract all modes that may contribute to the dynamic response.

Note Command objects can be inserted into Initial Conditions object to execute a restart of the solution process for the Modal Analysis.

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Analysis Types Apply Loads and Supports Basic general information about this topic … for this analysis type: The following loads are allowed for the linked analysis: • Acceleration (p. 694) • Pressure (p. 705) • Pipe Pressure (p. 708) • Force (p. 716) (applied to a face, edge, or vertex) • Line Pressure (p. 737) • Moment (p. 731) • Remote Force (p. 719) • Standard Earth Gravity (p. 698)

Support Limitations Note the following limitations: • If the Reference Temperature is set as By Body and that temperature does not match the environment temperature, a thermally induced transient load will result (from the thermal strain assuming a nonzero thermal expansion coefficient). This thermal transient loading is ignored for Transient Structural Analysis using Linked Modal Analysis System. • Remote Force is not supported for vertex scoping. • During a linked MSUP Harmonic analysis, if a Remote Force or Moment is specified with the Behavior property set to Deformable, the boundary conditions cannot be scoped to the edges of line bodies such that all of their nodes in combination are collinear. • Remote Force and Moment applied to a rigid body is not supported. • Moment is not supported for vertex scoping on 3D solid bodies because a beam entity is created for the load application. The beam entity changes the stiffness of the structural component shared and solved by the preceding modal analysis. • Joint probes, Energy Probe, and Strain Energy results are not supported when expanded from a Modal solution. • Cyclic symmetry models are not supported for a Transient Structural Analysis that is using a linked Modal Analysis System. • Spring probe only supports Elastic force result when expanded from modal solution where as it supports both Elastic force and Elongation results when expanded from transient solution. The Elastic force results include the spring damping effect if the Reduced method is selected from Modal Solver controls, and Store Complex Solution is set to No.

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Transient Thermal Analysis • Standard Earth Gravity is not allowed in conjunction with the Acceleration load. • Elemental Triads results are not available on solid bodies. • When the Step Controls are defined by Substeps, the time step value sent to the solver is based on the settings for the first load step. For the load steps greater than one, you may notice an inconsistent value of the number of sub-steps in the Details View or the Worksheet View. • For the Samcef solver, Hydrostatic Pressure and Pipe Pressure are not supported.

Notes • Remote Force and Moment loading combined with the Rigid contact behavior is allowed when the loading is scoped through a Remote Point. • To obtain the most accurate results, it is recommended that you specify Bonded as the contact Type and set the contact Formulation to MPC in the Details for the Contact Region. See the Contact Definition and Contact Advanced Category for more detailed information about these settings. • When the result is expanded from Modal Solution or when Reaction Object is scoped to a Contact Region, the Reaction Object requires both Nodal Forces and Calculate Reactions Output Controls settings to be turned On. If they are not set, the error message “A result is invalid with current output control settings” displays. For other cases, the Reaction Object requires only the Calculate Reactions Output Controls setting to be turned On. • The default value of Numerical Damping is different for full and mode superposition transient structural analyses. So, the results comparison of a model must be done by matching the Numerical Damping value settings in the Damping Controls section.

Transient Thermal Analysis Introduction Transient thermal analyses determine temperatures and other thermal quantities that vary over time. The variation of temperature distribution over time is of interest in many applications such as with cooling of electronic packages or a quenching analysis for heat treatment. Also of interest are the temperature distribution results in thermal stresses that can cause failure. In such cases the temperatures from a transient thermal analysis are used as inputs to a structural analysis for thermal stress evaluations. Transient thermal analyses can be performed using the ANSYS or Samcef solver. Many heat transfer applications such as heat treatment problems, electronic package design, nozzles, engine blocks, pressure vessels, fluid-structure interaction problems, and so on involve transient thermal analyses.

Point to Remember A transient thermal analysis can be either linear or nonlinear. Temperature dependent material properties (thermal conductivity, specific heat or density), or temperature dependent convection coefficients or radiation effects can result in nonlinear analyses that require an iterative procedure to achieve accurate solutions. The thermal properties of most materials do vary with temperature, so the analysis usually is nonlinear.

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Preparing the Analysis Create Analysis System Basic general information about this topic … for this analysis type: From the Toolbox, drag the Transient Thermal or the Transient Thermal (Samcef) template to the Project Schematic. Define Engineering Data Basic general information about this topic … for this analysis type: Thermal Conductivity, Density, and Specific Heat must be defined for a transient thermal analysis. Thermal Conductivity can be isotropic or orthotropic. All properties can be constant or temperature-dependent. Attach Geometry Basic general information about this topic … for this analysis type: There are no special considerations for a transient thermal analysis. Define Part Behavior Basic general information about this topic … for this analysis type: You can define a Thermal Point Mass for this analysis type. Define Connections Basic general information about this topic … for this analysis type: In a thermal analysis only contact is valid. Any joints or springs are ignored. With contact the initial status is maintained throughout the thermal analysis, that is, any closed contact faces will remain closed and any open contact faces will remain open for the duration of the thermal analysis. Heat conduction across a closed contact face is set to a sufficiently high enough value (based on the thermal conductivities and the model size) to model perfect contact with minimal thermal resistance. If needed, you can model imperfect contact by manually inputting a Thermal Conductance value.

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Transient Thermal Analysis By default, Contact Results (accessible through User Defined Results via CONTSTAT or CONTFLUX – see the User Defined Results for the Mechanical APDL Solver section.) are not written to the result file in a thermal analysis. To write them, issue the RSTSUPPRESS,NONE command via a Command object at the /SOLU level. Apply Mesh Controls/Preview Mesh Basic general information about this topic … for this analysis type: There are no specific considerations for transient thermal analysis itself. However if the temperatures from this analysis are to be used in a subsequent structural analysis the mesh must be identical. Therefore in this case you may want to make sure the mesh is fine enough for a structural analysis. Establish Analysis Settings Basic general information about this topic … for this analysis type: For a transient thermal analysis the basic controls are: Step Controls (p. 635), used to: i) specify the end time of the transient analysis ii) control the time step size and iii) create multiple steps when needed. The rate of loading could be important in a transient thermal analysis if the material properties vary rapidly with temperature. When such nonlinearities are present it may be necessary to apply the loads in small increments and perform solutions at these intermediate loads to achieve convergence. Multiple steps are needed if you want to change the solution settings, for example, the time step size or the solution output frequency over specific time spans in the transient analysis. Output Controls (p. 658) allow you to specify the time points at which results should be available for postprocessing. A transient analysis involves calculating solutions at several time points in the load history. However: i) you may not be interested in all the intermediate results and ii) writing all the results can make the results file size unwieldy. In this case you can restrict the amount of output by requesting results only at certain time points. Nonlinear Controls (p. 655) allow you to modify convergence criteria and other specialized solution controls. Typically you will not need to change the default values for this control. Analysis Data Management (p. 664) settings enable you to save specific solution files from the transient thermal analysis for use in other analyses. Define Initial Conditions Basic general information about this topic … for this analysis type:

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Analysis Types A transient thermal analysis involves loads that are functions of time. The first step in applying transient thermal loads is to establish initial temperature distribution at Time = 0. The default initial condition for a transient thermal analysis is a uniform temperature of 22°C or 71.6°F. You can change this to an appropriate value for your analysis. An example might be modeling the cooling of an object taken out of a furnace and plunged into water. You can also use the temperature results from a steady-state analysis of the same model for the initial temperature distribution. A casting solidification study might start with different initial temperatures for the mold and the metal. In this case a steady-state analysis of the hot molten metal inside the mold can serve as the starting point for the solidification analysis. In the first iteration of a transient thermal analysis, this initial temperature is used as the starting temperature value for the model except where temperatures are explicitly specified. In addition this temperature is also used to evaluate temperature-dependent material property values for the first iteration. If the Initial Temperature field is set to Non-Uniform Temperature, a Time field is displayed where you can specify a time at which the temperature result of the steadystate thermal analysis (selected in Initial Condition Environment field) will be used as the initial temperature in the transient analysis. A zero value will be translated as the end time (of the steady-state thermal analysis) and this value can not be greater than the end time. Apply Loads and Supports Basic general information about this topic … for this analysis type: The following loads are supported in a transient thermal analysis: • Temperature (p. 747) • Convection (p. 749) • Radiation (p. 753) • Heat Flow (p. 757) • Perfectly Insulated (p. 757) • Heat Flux (p. 759) • Internal Heat Generation (p. 762) • Imported Temperature (p. 846) • Imported Convection Coefficient (p. 840) In this analysis, the load’s magnitude could be a constant value or could vary with time as defined in a table or via a function. Details of how to apply a tabular or function load

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Special Analysis Topics are described in Defining Boundary Condition Magnitude (p. 848). In addition, see the Apply Loads and Supports section for more information about time stepping and ramped loads. Solve Basic general information about this topic … for this analysis type: The Solution Information object provides some tools to monitor solution progress. Solution Output continuously updates any listing output from the solver and provides valuable information on the behavior of the structure during the analysis. Any convergence data output in this printout can be graphically displayed as explained in the Solution Information section. You can also insert a Result Tracker object under Solution Information. This tool allows you to monitor temperature at a vertex as the solution progresses. Result Tracker is not available to the Samcef solver. Review Results Basic general information about this topic … for this analysis type: Applicable results are all thermal result types. Once a solution is available you can contour the results or animate the results to review the response of the structure. As a result of a nonlinear analysis you may have a solution at several time points. You can use probes to display the variation of a result item over the load history. Also of interest is the ability to plot one result quantity (for example, maximum temperature on a face) against another results item (for example, applied heat generation rate). You can use the Charts feature to develop such charts. Note that Charts are also useful to compare results between two analyses of the same model.

Special Analysis Topics This section includes special topics available the Mechanical application for particular applications. The following topics are included: Electromagnetics (EM) — Mechanical Data Transfer External Data Import External Data Export Fluid-Structure Interaction (FSI) Icepak to Mechanical Data Transfer Mechanical-Electronics Interaction (Mechatronics) Data Transfer Polyflow to Mechanical Data Transfer Simplorer/Rigid Dynamics Co-Simulation Static Analysis From Rigid Dynamics Analysis Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types Submodeling System Coupling Thermal-Stress Analysis One-way Acoustic Coupling Analysis Rotordynamics Analysis Fracture Analysis Composite Analysis

Electromagnetics (EM) — Mechanical Data Transfer You can import data generated by the HFSS, Maxwell, or Q3D Extractor application and perform an analysis in Mechanical by applying the imported loads. In the case of loads originating from HFSS and Maxwell, you can also export the temperature or deformation results obtained from the Mechanical analysis so that they can be imported back into HFSS or Maxwell. Furthermore, you can import: • Thermal loss data generated by the HFSS, Maxwell, or Q3D Extractor applications and perform a thermal analysis using the imported load. The resulting temperature results then can be exported and applied during the subsequent solution of the upstream Maxwell analysis. • Force densities generated by the Maxwell application and perform a static or transient structural analysis using the data. The resulting deformation results can then be exported and applied during the subsequent solution of the upstream Maxwell analysis. • Forces and moments generated by the Maxwell application and perform a harmonic analysis using the load.

Overall Workflow for an EM — Mechanical Analysis 1. Create and solve the electromagnetic application using HFSS, Maxwell, or Q3D Extractor. 2. Drag and drop a steady-state thermal, transient thermal, static structural, transient structural, or harmonic (Maxwell only) template on top of the HFSS, Maxwell, or Q3D Extractor systems solution cell to enable the data transfer. 3. Attach geometry to the Mechanical application, and then double-click Setup to open the Mechanical window. An Imported Load or an Imported Remote Load folder is added under the Environment folder, by default. 4. As required, you can add or generate imported loads and set their options. 5. Perform all steps to set up a Steady-State Thermal, Transient Thermal, Static Structural, Transient Structural, or Harmonic Response analysis. Specify mesh controls, boundary conditions, and solution settings as you normally would. 6. Solve the ANSYS analysis. 7. If applicable, export your results to make them available for import by the upstream applications. See the following sections for more detailed procedures to import and/or export loads during Thermal, Structural, and Harmonic analyses. • Importing Data into a Thermal or Structural (Static or Transient) Analysis (p. 303) • Importing Data into a Harmonic Analysis (p. 305)

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Special Analysis Topics • Exporting Results from a Thermal or Structural Analysis (p. 308)

Importing Data into a Thermal or Structural (Static or Transient) Analysis This feature enables you to perform a one-way Electromagnetics (EM) — Mechanical interaction problem by solving the electromagnetic analysis of the geometry in the HFSS, Maxwell, or Q3D Extractor applications, importing the thermal or structural results into the ANSYS Mechanical application where the defined load is applied to a thermal or structural analysis which is then solved and post processed. For a thermal analysis, you can import Imported Heat Generation and Imported Heat Flux load types. For a structural analysis you can import Imported Body Force Density (illustrated below) and Imported Surface Force Density load types.

Add the Imported Load Follow these steps to add an imported load and associate it with parts of the geometry. 1. Double-click on the Model cell in your analysis system to open the Mechanical application. 2. Click on the Imported Load group object. In the Details view, set the following field as needed: • If you want to suppress all of the loads under this Imported Load group, set the Suppressed field to Yes. 3. There are several ways to select an imported load and associate it with a part of your model. • Click on an Imported Load Group object in the tree, click on a part of the model, then right-click on Imported Loads and from the Import menu item select the desired load type from the allowed imported load types. The load will be applied to the object you selected on the model.

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Analysis Types • Click on an Imported Load Group object in the tree, then click on the Imported Loads button in the toolbar and select the desired load type from the allowed imported load types. In the Details view, click on the Geometry field. Select the objects in the model to which you want to apply the load and click the Apply button in the Geometry field. • Right-click on the Imported Loads Group object that was just added to the tree and select the desired load type from the allowed imported load types. In the Details view, click on the Geometry field. Select the objects in the model to which you want to apply the load and click the Apply button in the Geometry field.

Note Heat generation loads scoped to a surface body use the constant thickness value specified in the details view of the surface body object when data is imported. Surface body thickness defined using the thickness object is not accounted for when data is imported.

Set the Imported Load Options 1. Click on the imported load object that you’ve added to the tree. 2. Select the desired Ansoft solution you would like to import the load from. Some of the properties in the Details view and Data View tab are filtered based on this selection. 3. Change any of the fields in the Details View as needed: • Scoping Method– Select the method of choosing objects to which the load is applied: Geometry Selection or Named Selection. • Geometry or Named Selection– Use these fields to choose the objects to which the load is applied, as appropriate from your Scoping Method choice. • Suppressed– Select Yes to suppress this load • Ansoft Surface(s)– Select the Ansoft Surface(s) for a Heat Flux or Surface Force Density load or Ansoft Volume(s)– Select the Ansoft Volume(s) for a Heat Generation or Body Force Density load

Set the Imported Load Analysis Options You can specify when the imported data should be applied and also modify the imported data, either by adding an offset or by using a scale factor. To see the analysis setting for a load, click on the object that you’ve added to the tree. The analysis options appear in the Data View tab of the window below the model. Make any changes to the load’s analysis options as indicated below. Change any of the columns in the Data View tab as needed: • Source Frequency — Select from the drop-down list one of the frequencies supplied from the transfer file. The load values associated with this frequency will be imported.

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Special Analysis Topics • Source Time — Select from the drop-down list one of the Source Times supplied from the transfer file. The load values associated with this time will be imported. • For thermal loads from Maxwell transient solutions, you must select from the drop-down list the desired Source Start Time and Source Stop Time to define the interval for integrating the power loss density distribution. • Analysis Time — Choose the analysis time at which the load will be applied. This must coincide with the end time of a step defined in the Analysis Settings object in the tree. • Scale — The amount by which the imported load values are scaled before applying them. • Offset — An offset that is added to the imported load values before applying them. You must re-solve after making any changes to the analysis options of a load. You can define multiple rows in the Data View tab to import additional data from the selected Ansoft solution and apply the rows at different analysis times. If multiple rows are defined in the Data View tab, you can display imported values at different time steps by changing the Active Row option in the Details pane. Right-click the Imported Load object and click Import Load to import the load. When the load has been imported successfully, a contour plot of the temperatures will be displayed in the Geometry window and a summary of the transfer is displayed as a comment in the particular load branch.

Importing Data into a Harmonic Analysis The following procedure assumes that you have properly defined your model in Maxwell and that the source and target systems are connected on the Workbench Project Schematic. Given that, follow these steps to import data and associate it with parts of the geometry. 1. Double-click the Model cell of your harmonic analysis system to open the Mechanical application. 2. Select the Imported Remote Loads object. In the Details view, define the following properties, if necessary: Scoping Method This property defines the geometry on which the imported data is applied. Face selections are supported for 3D analyses and edges for 2D analyses. Options include: • Geometry Selection: default setting, indicating that the load is applied to a geometry or geometries. When the Scoping Method is set to Geometry Selection, the Geometry property becomes visible. Use this property to specify your desired geometry selections. Once specified, the field displays the type of geometry (Face or Edge) and the number of geometric entities (1 Face, 2 Edges) to which the load has been applied using the selection tools. • Named Selection: indicates that the geometry selection is defined by a Named Selection. When the Scoping Method is set to Named Selection a Named Selection property becomes visible. This property provides a drop-down list of available user-defined Named Selections. Ansoft Solution Select the desired Maxwell solution you would like to import the load from.

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Analysis Types Remote Points Select the appropriate option to generate Internal or Globally Available remote points. On Data Refresh This option is available when the Remote Points options is set to Globally Available. The Regenerate option deletes the remote points that were created during the previous import and adds new remote points when data is imported. The Reuse Remote Points option reuses the previously added remote points and only updates the scoping and location, if necessary. Import Status This read-only property displays the status of the import. One of the following status conditions will exist: • Data Unavailable: no data is available to perform the import. • Obsolete: data is available to be imported, but no data has been imported or the data is obsolete and should be re-imported. • Update: all data has been imported. • Import Failed: an error occurred during the import process and no data was imported Suppressed If you want to suppress all of the loads under this Imported Remote Loads object, set this property to Yes. 3. Once you have defined the necessary import options, right-click the Imported Remote Loads object and select Generate Remote Loads. This action imports the source data and associates it with the selected target geometry. Once executed, Mechanical adds objects to the tree based on the source data. The following items will be added into the tree based on the source data. For each location that Maxwell reports the calculated forces, Mechanical: • Adds two Remote Force objects and two Moment objects with the imported data. For each of these loading types, one object is inserted under the Imported Remote Loads group object for real components and another one is inserted for imaginary components (and the Phase Angle property is automatically set to 90o). Each set of four loads are named with a Group ID number, as illustrated in the following example.

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Special Analysis Topics

• Creates a Remote Point at that location and associates it with the group of four loads. The Remote Point is named with the same Group ID number as the set of load group.

Note When using internal remote points, if you change the scoping or behavior of a load, all loads of the group automatically update because they share the same remote point.

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For each scoped reference (face or edge), applied using the Scoping Method property on the Imported Remote Load object, Mechanical finds the closest Remote Point and assigns the reference as scoping for that Remote Point. 4. Specify mesh controls, boundary conditions, and solution settings. 5. Solve the analysis.

Exporting Results from a Thermal or Structural Analysis If you have solved an analysis containing loads imported from Maxwell or HFSS, you can choose to export temperature or deformation results and apply them during the subsequent solve of the upstream analysis, if this option was previously set in the upstream analysis. • Temperature results can be exported back to HFSS or Maxwell from a thermal analysis • Deformation results can be exported to Maxwell from a structural analysis.

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Special Analysis Topics Click on the Imported Load Group object in the tree to view the Details for the load. If the export option is set, you will see an Export Definition section in the Details View. The Setup field allows you to specify the Ansoft Setup for which the exported results will be written. The All option for the Setup field exports results to all the setups requesting feedback.

In the Details view you can also set the analysis time at which results are exported. The default is the end time of the analysis, which you select by entering 0. You must enter a value between 0 and the end time of the analysis. If you want to export the results automatically at the end of the analysis, click on the Imported Load (Ansoft) object in the tree before you start the analysis. In the Details panel, set the Export After Solve field to Yes. The results will be written when the solution has finished. If you want to export the results manually after the analysis, click on the Imported Load (Ansoft) object in the tree before you start the analysis. In the Details panel, set the Export After Solve field to No. To export the file after the solution, right-click on the Imported Load (Ansoft) object in the tree. Select Export Results. The results will be written to the file.

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Analysis Types If necessary, you can modify the load transfer Mapper Settings for the export.

Note Refer to the Ansoft application documentation for more details on settings required to support the export from the Mechanical application to the Ansoft application. Results can only be exported to setups that have contributed to the current solution.

External Data Import This feature enables you to import data from one or more text files and apply it in a Mechanical application analysis. Data can be imported into a static structural, transient structural1 (p. 317), steady-state thermal, transient thermal or thermal-electric analysis. To import data from an external file: 1.

In the Project Schematic, add any number of files to an External Data system and specify the necessary details. • When multiple files are added to the same External Data system, each file is given a unique identifier (that is, File1, File2, and so on). These identifiers are used in conjunction with the data identifiers (Pressure1, Thickness1, and so on) to identify and apply the dataset(s) within Mechanical. • If your files contain data for the same nodal coordinates, or if only one of your files contains the nodal information, you can choose the Master option in the External Data system to designate a master file. This option notifies the mapping utility that the group of files, defined in the External Data system, share the same nodal information. The nodal information is therefore processed and stored only from the master file. This greatly reduces the memory usage by only allocating space for the nodes once, not once per file. It can also result in much faster import times as only one mapping operation will be required. • Mechanical APDL CDB files can be added as a master mesh in the External Data system; for details, see Importing a CDB File as Input in the Workbench User’s Guide.

2.

To transfer data to Mechanical, create a link between the Setup cell of the External Data system and that of an applicable downstream system. • To transfer shell thickness data to Mechanical, right-click the Setup cell of the External Data system and select Transfer Data to New, a link is created to the Model cell of a new Static Structural system. If you select Transfer Data to New > <mechanical system>, this operation automatically creates a link to the Model cell of the Mechanical system. Alternatively, you can drag the Setup cell of the External Data and drop it onto the Model cell of a Mechanical system to create the link. • To transfer load data to Mechanical, drag the Setup cell of the External Data system and drop it onto the Setup cell of an applicable Mechanical system. • When an External Data System is connected to a system using the Samcef solver, the following quantities cannot be used: Body Force Density, Stress, Strain, Heat Flux, and the Emag Condition.

3.

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Attach geometry to the analysis system, and then double-click Setup to open the Mechanical window.

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Special Analysis Topics If your simulation has a shell thickness defined from an External Data system, an Imported Thickness folder is added under the Geometry folder. 1.

Select appropriate geometry in the Details view, and then click Apply.

2.

Select appropriate options in the Details view. You can modify the mapping settings to achieve the desired mapping accuracy.

3.

You can specify a thickness value for the unmapped target nodes using the Unmapped Data Value property. By default, a zero thickness value is assigned to the unmapped nodes.

Important For the ANSYS solver, the thickness value at each node must be greater than zero.

4.

Right-click the Imported Thickness, and then click Import Thickness to import the thickness. When the thickness has been imported successfully, a contour plot will be displayed in the Geometry window and any mesh display will be based upon the mapped thickness of the elements.

If your simulation has load data defined from an External data system, an Imported Load folder is added under the Environment folder. 1.

To add an imported load, click the Imported Load folder to make the Environment toolbar available, or right-click the Imported Load folder and select the appropriate load from the context menu.

2.

Select appropriate geometry in the Details view, and then click Apply.

3.

In a 3D structural analysis, if the Imported Body Temperature load is scoped to one or more surface bodies, the Shell Face option in the details view enables you to apply the temperatures to Both faces, to the Top face(s) only, or to the Bottom face(s) only. See Imported Body Temperature for additional information.

4.

When mapping data to surface bodies, you can control the effective offset and thickness value at each target node, and consequently the location used during mapping, by using the Shell Thickness Factor property. By default, the thickness value at each target node is ignored when data is mapped. You can choose to enter a positive or negative value for the Shell Thickness Factor. This value is multiplied by each target node’s physical thickness and is used along with the node’s offset to determine the top and bottom location of each target node. A positive value for the Shell Thickness Factor uses the top location of each node during mapping, while a negative value uses the bottom location of each node. For example: • A value of 0.0 means that the physical thickness and offset of the surface body nodes will be ignored; all target nodes are mapped at default surface body locations.

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• A value of 1.0 means that the thickness used for a target node will be equal to the physical thickness value specified for that node. The top location of the node will be used during the mapping process.

• A value of -2.0 means that the thickness used for a target node will be equal to twice the physical thickness value specified for that node. The bottom location of the node will used during the mapping process.

The Viewer will look similar to the following for a value of –1.0. The colored dots represent the location and corresponding values of the source nodes. In this case, each target node will be projected using its physical thickness value to its bottom location and then mapped.

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Special Analysis Topics

5.

Select appropriate options in the Details view. You can modify the mapper settings to achieve the desired mapping accuracy. Mapping can be validated by using Mapping Validation the objects. • For pressure loads, you can apply the load in the direction normal to the face or by specifying a direction. Setting Define By to Components enables you to define the direction by specifying the x, y, and z magnitude components of the load. The z component is not applicable for 2-D analyses. For pressure loads in Harmonic Response, you can apply both real and imaginary components of the loads. • In a 3D analysis, if the Triangulation mapping algorithm is used, the Transfer Type mapping option defaults to Surface when an Imported Temperature or Imported Body Temperature load scoping is only on shell bodies. If the scoping is on shell bodies and other geometry types, the Transfer Type mapping option will default to Volumetric. In such cases, to obtain a more accurate mapping, you should create a separate imported load for geometry selections on shell bodies, and use the Surface option for Transfer Type. See Transfer Type under Mapping Settings for additional information. • For Imported Pressure loads, you can apply the load onto centroids or corner nodes using the Applied to property in the Details view. See Imported Pressure for additional information.

6.

For each load step, if an Imported Displacement and other support/displacement constraints are applied on common geometry selections, you can choose to override the specified constraints by using the Override Constraints option in the details of the Imported Displacement object. By default, the specified constraints are respected and imported displacements are applied only to the free degrees of freedom of a node.

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For Vector2 (p. 317) and Tensor3 (p. 317) loads, the Coordinate System property can be used to associate the component identifiers, defined in the worksheet, to a particular coordinate system. This option is useful when the source data is defined, or needs to be defined, with respect to a coordinate system that is not aligned with the Global coordinate system. If a cylindrical coordinate system is chosen, the data is interpreted to be in the radial, tangential, and axial directions. By default, the Source coordinate system is used.

Note The Source Coordinate System drop-down option is an internal coordinate system used by Mechanical and is not visible in the tree. It represents the coordinate system that was used to define source points in the upstream External Data system. If there are no Rigid Transformations (Theta XY/YZ/ZX) defined in the upstream External Data system, the Source Coordinate System is the same as the Global Coordinate System.

8.

Under Data View, select the desired data Identifier, for the imported load. The data identifier (File Identifier: Data Identifier) strings are specified in the upstream External Data system. You can also change the Analysis Time/Frequency and specify Scale and Offset values for the imported loads.

• For Vector2 (p. 317) and Tensor3 (p. 317) loads, if the Define By property is set to Components you should select data identifiers that represent the x/radial, y/tangential, and z/axial magnitude components of the load. For Vector2 (p. 317) and Tensor3 (p. 317), the components are applied in the Coordinate System specified in the Details view. The z component is not applicable for 2-D analyses. For Imported Displacement load, you can choose to keep a component free, or fixed (displacement = 0.0) by selecting the Free or Fixed option from the list of data identifiers. For all other loads, you can choose to ignore a component if you do not have data for that direction by selecting the Ignore identifier from the drop-down list. – For Imported Pressure/Imported Velocity in Harmonic response, you should select data identifiers for both real and imaginary components. You can also specify Scale and Offset for both real and imaginary components.

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Special Analysis Topics • For Imported Convections, you should select data identifiers for film coefficient and ambient temperature. You can also specify Scale and Offset values for both film coefficient and ambient temperature.

9.

Right-click in the Data View and select Add row to specify additional data for a different analysis time/frequency.

10. Change any of the columns in the Data View tab as needed: • Magnitude \ Film Coefficient \ Ambient Temperature Select the appropriate data identifier that represents the load values to be applied from the drop-down list. • X Component Select the appropriate data identifier that represents the x component of the load values to be applied from the drop down list. • Y Component Select the appropriate data identifier that represents the y component of the load values to be applied from the drop down list. • Z Component Select the appropriate data identifier that represents the z component of the load values to be applied from the drop down list.

Note If you do not have data for a direction you can choose to ignore that component by selecting Ignore from the appropriate drop-down box. Select the Fixed option from the drop down list to make the component constant with a value of zero or the Free option for the component to be without any constraints. If multiple files have been used in the upstream External Data system, the data identifiers for component-based vector or convection loads must come from the same file or from files that have a master file association. For example, you can select File1:PressureX, File1:PressureY, and File1:PressureZ, but you cannot select File1:PressureX, File2:PressureY, File3.PressureZ (assuming that File1, File2, and File3 do not have a master file association).

• XX, YY, ZZ, XY, YZ, and ZX Component Select the appropriate data identifiers to represent the components of the symmetric tensor to be applied from the drop down list. • Analysis Time/Frequency Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types Choose the analysis time at which the load will be applied. • Scale The amount by which the imported load values are scaled before applying them. • Offset An offset that is added to the imported load values before applying them. 11. In the project tree, right-click the Imported Load, and then click Import Load to import the load. 12. When the load has been imported successfully, a contour or vector plot will be displayed in the Geometry window. • For Vector2 (p. 317) loads, contours plots of the magnitude (Total) or X/Y/Z component can be viewed by changing the Data option in the details pane. Defaults to a vector plot (All). • For Tensor3 (p. 317) loads, contours plots of the Equivalent (von-Mises) or XX, YY, ZZ, XY, YZ and ZX components can be viewed by changing the Data option in the details pane. Defaults to a Vector Principal plot. • For Imported Convections loads, contours plots of film coefficient or ambient temperature can be viewed by changing the Data option in the details pane. • For complex load types, e.g. Pressure/Velocity in Harmonic Response, the real/imaginary component of the data can be viewed by changing the Complex Data Component option in the details pane.

Note The range of data displayed in the graphics window can be controlled using the Legend controls options. See Imported Boundary Conditions for additional information.

13. For Imported Force loads, additional result information is reported in the Transfer Summary. The reported source and target force results may be used to validate the mapping and also to appropriately apply a scaling factor. 14. If multiple rows are defined in the Data View, imported values at different time steps can be displayed by changing the Active Row option in the details pane. 15. To activate or deactivate the load at a step, highlight the specific step in the Graph or Tabular Data window, and choose Activate/Deactivate at this step! See Activation/Deactivation of Loads for additional rules when multiple load objects of the same type exist on common geometry selections.

Important • For Vector2 (p. 317) and Tensor3 (p. 317) loads, when the Define By property is set to Components, any rotation transformations (Theta XY/YZ/ZX) specified in the External Data system will be appropriately applied to the mapped data if the Coordinate System is specified as Source Coordinate System. If any other coordinate system is specified then the components are applied in the specified Coordinate System. Rotations, resulting from using a cylindrical projection

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Special Analysis Topics coordinate system, for 2D to 3D mapping are also appropriately applied to the mapped data. Rotations, resulting from analytical transformations specified in the External Data system, do not get applied to the mapped data. • For Imported Displacements, selecting the Free identifier for a source component will result in the corresponding target component being left unconstrained and free to deform in that direction, whereas Fixed identifier results in a value of zero being applied. For other load types, a value of zero is applied on selecting the Ignore component.

1 — The rigid dynamics solver is not supported. 2 — Imported Displacement, Imported Force, Imported Pressure and Imported Velocity. 3 — Imported Stress and Imported Strain.

External Data Export These features enable you to export results data to one or more text files and use them in an External Data system. The External Data system can then be linked to a downstream system in order to apply the exported data as boundary conditions; see External Data for more information. Two methods of exporting are available. The first method uses the right-click Export option on a Result object, see Exporting Data. Be sure to include the Node Locations which are off by default as described in the Exporting Data section. The second method, available for thermal analyses, will export the temperatures and heat flows on any surface with a Fluid Solid Interface boundary condition; see Fluid Solid Interface for more information.

Fluid-Structure Interaction (FSI) Fluid-Structure Interaction (FSI) analysis is an example of a multiphysics problem where the interaction between two different physics phenomena, done in separate analyses, is taken into account. From the perspective of the Mechanical application, an FSI analysis consists of performing a structural or thermal analysis in the application, with some of the loads (forces or temperatures, for example) coming from a corresponding fluid analysis or previous CFD analysis. In turn, the results of the mechanical analysis may be used as loads in a fluids analysis. The interaction between the two analyses typically takes place at the boundaries that the mechanical model shares with the fluids model. These boundaries of interaction are collectively called the fluid-structure interface. It is at this interface where the results of one analysis are passed to the other analysis as loads. A general way of tying two otherwise independent analyses together is described in System Coupling (p. 342). The specific use of System Coupling as one way to perform certain FSI analyses is mentioned where applicable in the following sections. For one specific multiphysics problem, the structural thermal-stress analysis, an FSI analysis is not always required. If the thermal capabilities of the Mechanical application are sufficient to determine a proper thermal solution, an FSI approach (using separate applications for separate analyses) is not required and the thermal-stress analysis can be done entirely within the Mechanical application. In the case where the thermal solution requires the specialized capabilities of a CFD analysis, the structural thermalstress analysis is done using the FSI approach. The CFD analysis is done first, then the calculated temperatures at the fluid-structure interface are applied as loads in the subsequent mechanical analysis.

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Analysis Types Typical applications of FSI include: • Biomedical: drug delivery pumps, intravenous catheters, elastic artery modeling for stent design. • Aerospace: airfoil flutter and turbine engines. • Automotive: under-the-hood cooling, HVAC heating/cooling, and heat exchangers. • Fluid handling: valves, fuel injection components, and pressure regulators. • Civil engineering: wind and fluid loading of structures. • Electronics: component cooling. The Mechanical application supports two types of Fluid-Structure Interaction: one-way transfer and twoway transfer. In one-way FSI, CFD results are applied as loads in the mechanical analysis, but the results of the mechanical analysis are not passed back to a fluids analysis. In two-way FSI, the results of the mechanical analysis are passed back as loads to the fluids model. Two-way FSI is important when the mechanical analysis could produce results that, when applied as loads in the fluids analysis, would significantly affect the fluids analysis.

One-Way Transfer FSI In a one-way transfer FSI analysis, the CFD analysis results (forces, temperatures, convection loads, or heat flows) at the fluid-structure interface are transferred to the mechanical model and applied as loads. The subsequently calculated displacements or temperatures at the interface are not transferred back to the CFD analysis. One-way transfer is appropriate when displacements and temperatures differentials calculated in the Mechanical application are not large enough to have a significant impact on the fluid analysis. There are four supported applications of a one-way FSI analysis: 1. Pressure results from a CFD analysis are input as applied forces in a structural analysis at the fluid-structure interface. 2. Temperature results from a heat transfer CFD analysis are input as body loads in a structural analysis to determine the thermally induced displacement and stresses (thermal-stress analysis). 3. Convections from a heat transfer CFD analysis are input as convection boundary conditions (film coefficients and bulk temperatures) in a thermal analysis at the fluid-structure interface. 4. Temperatures or heat flows from a heat transfer CFD analysis are input as temperature or heat flow boundary conditions in a thermal analysis at the fluid-structure interface. There are two methods available for performing a one-way FSI analysis: importing loads and System Coupling. See Using Imported Loads for One-Way FSI (p. 319) and System Coupling (p. 342), respectively.

Two-Way Transfer FSI In a two-way transfer FSI analysis, the CFD analysis results (forces, temperatures, heat flows, or heat transfer coefficients and near wall temperatures) at the fluid-structure interface are transferred to the mechanical model and applied as loads. Within the same analysis, the subsequently calculated displacements, temperatures, or heat flows at the fluid-structure interface are transferred back to the CFD analysis. Two-way transfer is appropriate when displacements and temperature differentials calculated in the Mechanical application are large enough to have a significant impact on the fluid analysis. 318

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Special Analysis Topics Because of the two-way interaction between the two analyses, the analyses are looped through repeatedly until overall equilibrium is reached between the Mechanical application solution and CFD solution. Twoway FSI is supported between Mechanical and Fluent and Mechanical and CFX. In either case, you set up the static or transient structural portion of the analysis in the Mechanical application, including defining one or more fluid-structure interface boundary conditions. You continue the analysis in Fluent or CFX, and view the structural results in the Mechanical application. For more information on two-way FSI using Mechanical and Fluent, see System Coupling (p. 342). For more information on two-way FSI using Mechanical and CFX, see Coupling CFX to an External Solver: ANSYS Multi-field Simulations in the CFX-Solver Modeling Guide.

Note In a System Coupling setup, if you apply an external force or external heat flow on the same region as a Fluid-Structure Interaction load, this external variable will not be acknowledged by the Mechanical APDL solver.

Using Imported Loads for One-Way FSI This feature enables you to import fluid forces, temperatures, and convections from a steady-state or transient CFD analysis to a Mechanical application analysis. This one-way transfer of face forces (tractions) at a fluid-structure interface allows you to investigate the effects of fluid flow in a static or transient structural analysis. Similarly the one-way transfer of temperatures or convection information from a CFD analysis can be used in determining the temperature distribution on a structure in a steady-state or transient thermal analysis or to determine the induced stresses in a structural analysis. To import loads from a CFD analysis: 1. In the Project Schematic, add an appropriate analysis with data transfer to create a link between the solution of a CFD analysis and the newly added analysis. 2. Attach geometry to the analysis system, and then double-click Setup to open the Mechanical window. An Imported Load folder is added under the Environment folder, by default. 3. To add an imported load, click the Imported Load folder to make the Environment toolbar available or right mouse click on the Imported Load folder and select the appropriate load from the context menu. 4. On the Environment toolbar, click Imported Load, and then select an appropriate load. 5. Select appropriate geometry, and then click Apply. 6. In a structural analysis, if the Imported Body Temperature load is scoped to one or more surface bodies, the Shell Face option in the details view allows you to apply the temperatures to Both faces, to the Top face(s) only, or to the Bottom face(s) only. See Imported Body Temperature for additional information. 7. Select appropriate options in the Details view. a. Under Transfer Definition, • For surface transfer, click the CFD Surface list, and then select the corresponding CFD surface. • For volumetric transfer, click the CFD Domain list, and then select the corresponding CFD Domain. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types b. For CFD Convection loads only: Select the appropriate Ambient Temperature Type.

Note CFD Near-Wall Ambient (bulk) Temperature (default): This option uses the fluid temperature in the near-wall region as the ambient temperature for the film coefficient calculation. This value will vary along the face. Constant Ambient Temperature: This constant value applies to the entire scoped face(s). The film coefficient will be computed based on this constant ambient temperature value. Use of a constant ambient temperature value in rare cases may produce a negative film coefficient if the ambient temperature is less than the local face temperature. If this is the case, you can define a Supplemental Film Coefficient. This value will be used in place of the negative computed film coefficient and the ambient temperature adjusted to maintain the proper heat flow.

8. Under Data View, select the Source Time, for the imported load. The Source Time Step value changes based on the source time you select. If the selected source time corresponds to more than one source time step, you will also need to select the desired time step value. You can also change the Analysis Time and specify Scale and Offset values for the imported loads. 9. In the Project tree, right-click the imported load, and then click Import Load to import the load. When the load has been imported successfully, a contour plot will be displayed in the Geometry window. After the solution is complete, a CFD Load Transfer Summary is displayed as a Comment in the particular CFD load branch. The summary contains the following information: • For a CFD Pressure load: the net force, due to shear stress and normal pressure, on the face computed in CFD and the net force transferred to the Mechanical application faces. • For a CFD Temperature load: For surface transfers — the average computed temperature on the CFD boundary and the corresponding average mapped temperature on the Mechanical application faces. For volumetric transfers – the average, maximum, and minimum temperature of the CFD domain and the corresponding Mechanical Application body selection(s). • For a CFD Convection load: the total heat flow across the face, and the average film coefficient and ambient temperature on the face. The computed and mapped face data may be compared in order to get a qualitative assessment of the accuracy of the mapped data. The following is an example of a CFD Load Transfer Summary for a CFD Pressure load.

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Special Analysis Topics

Note The force values shown in the CFD Load Transfer Summary should only be used as a qualitative measure of the load transferred from CFD to the Mechanical application mesh. In the example above, the closer the CFD Computed forces are to the Mechanical application Mapped Forces, the better the mapping. The actual force transferred to the Mechanical application is reflected in the reaction forces. The following topics are covered in this section: Face Forces at Fluid-Structure Interface Face Temperatures and Convections at Fluid-Structure Interface Volumetric Temperature Transfer CFD Results Mapping

Face Forces at Fluid-Structure Interface You can use results at a fluid-structure interface from a CFD analysis as face forces (from the vector sum of the normal pressures and shear stresses) on corresponding faces in the Mechanical application. The import process involves interpolating a CFD solution onto the Mechanical application face mesh. This requires that the following conditions are met: • The fluid-structure interface must be a defined boundary in CFD. • The location of the CFD boundary (with respect to the global Cartesian coordinate system) must be the same as the corresponding face(s) in the Mechanical application model. Refer to the Imported Boundary Conditions (p. 834) section for more information.

Face Temperatures and Convections at Fluid-Structure Interface This feature allows the transfer of either of the following thermal solutions from a CFD solution boundary to a corresponding face in the Mechanical application model: • Temperatures at the fluid-structure interface. • Film coefficients and bulk temperature values at the fluid-structure interface. The import process involves interpolating a CFD solution onto the Mechanical application face mesh. This requires that the following conditions are met: • The fluid-structure interface must be a defined boundary in CFD. • The location of the CFD boundary (with respect to the global Cartesian coordinate system) must be the same as the corresponding face(s) in the Mechanical application model.

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Analysis Types Refer to the Imported Loads section for more information.

Volumetric Temperature Transfer You can transfer temperature results from a CFD analysis and apply them as body loads in the Mechanical application. The import process involves interpolating a CFD solution onto the mesh for the bodies selected in the Mechanical application. This requires that the following condition is met: • The location of the bodies in the Mechanical application model (with respect to the global Cartesian coordinate system) must be the same as the corresponding CFD domains.

CFD Results Mapping When mapping CFD results onto the Mechanical application face(s) the Mechanical nodes are projected on to the CFD face. All the Mechanical application face nodes will map to the CFD face according to the following rules: a. Project normal to the CFD mesh faces. b. If rule a fails, project to the closest edge. c. If rule b. fails, project to the closest node on the CFD face. Rule c. will always work, so in the end every node will get some kind of mapping. However the most accurate load mapping occurs for nodes projected normal to the mesh face. The percentage of the Mechanical application nodes that mapped successfully using rule a. above is reported in the diagnostics. When the Mechanical application mesh is very coarse, there can be some misses near the edges of the CFD boundary. However all nodes become mapped eventually. The accuracy of force transfer improves as the Mechanical application mesh is refined. When mapping CFD domain results onto the corresponding Mechanical Application body selection(s), all the Mechanical Application nodes that cannot be mapped to the CFD domain will be set to the average temperature.

Icepak to Mechanical Data Transfer The Mechanical application allows you to transfer temperature data from Icepak into Mechanical. This process involves the import of temperature data from the solid objects defined in Icepak onto the geometry defined in Mechanical. As the meshes used in Icepak and Mechanical could be quite different, mapping the temperatures involves an interpolation method between the two. Once the mapping is completed, it is possible to view the temperatures and utilize them to perform a Mechanical analysis. The workflow is outlined below.

Workflow for Icepak Data Transfer 1. In Icepak, perform all steps for an Icepak analysis by creating the Icepak model, meshing and solving the model. After the solution has finished, Icepak writes out the temperature data for each of the solid objects to a file with the extension loads. In addition, a summary file with the extension load summary is written out. 2. Drag and drop a Mechanical cell, which could be one of Static Structural, Steady-State Thermal, Transient Structural, Transient Thermal, or Thermal-Electric analysis on top of the Icepak Solution cell.

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Special Analysis Topics 3. Import the geometry or transfer the geometry into the Mechanical application. Double click the Setup cell to display the Mechanical application. 4. In the Details section of Imported Temperature or Imported Body Temperature under Imported Loads, you will first select the Scoping method. Select Geometry Selection as the Scoping method unless you have created a Named Selection. See Scoping Analysis Objects to Named Selections (p. 448) for a detailed description. 5. If Geometry Selection is selected as the Scoping method, pick the geometry using Single select or Box select and click Apply or select a Named Selection object in the drop down list. 6. In a structural analysis, if the Imported Body Temperature load is scoped to one or more surface bodies, the Shell Face option in the details view allows you to apply the temperatures to Both faces, to the Top face(s) only, or to the Bottom face(s) only. See Imported Body Temperature for additional information. 7. To suppress this load, select Yes. Otherwise, retain the default setting. 8. In the drop-down field next to Icepak Body, select one body at a time, All or a Named Selection. If selecting an individual body, make sure your selection corresponds to the volume selected in step 5. If All bodies were selected, select All. 9. The Icepak Data Solution Source field displays the Icepak temperature source data file. 10. You can modify the Mapper Settings to achieve the desired mapping accuracy. 11. Click on the imported load object, then right-click and select Import Load. This process first generates a mesh, if one doesn’t already exist, and then interpolates the temperatures from the Icepak mesh onto the Mechanical mesh. This process might take long if the mesh size or the number of bodies is large. Improving the quality of the mesh will improve the interpolation results but the computation time may be higher.

Note If the import is successful, you can see the temperature plot in the graphics display window. If multiple time steps refer to the same time, an error will be displayed in the Mechanical message window.

12. You can apply other boundary conditions and click Solve to solve the analysis.

How to Set up a Transient Problem 1. In Icepak, perform all steps for a transient Icepak analysis and solve the model. 2. Perform steps 2 – 9 as described above. 3. Click the Analysis Settings object in the tree. Begin adding each step’s End Time values for the various steps to the tabular data window. You can enter the data in any order but the step end time points will be sorted into ascending order. The time span between the consecutive step end times will form a step. You can also select a row(s) corresponding to a step end time, click the right mouse button and choose Delete Rows from the context menu to delete the corresponding steps. See Establish Analysis Set-

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Analysis Types tings (p. 134) for further information. Whenever a new row is added or deleted, the imported body temperature data view will be updated to match the number of rows in the Analysis Settings. 4. Click on the imported load object and the Data View tab with updated Analysis Times is displayed. If the Analysis Time is different, the Source Time will display the original time, matching to the closest available Source Time coming from Icepak. If the match is not satisfactory, you can select a Source Time(s) from the drop-down list and Mechanical will calculate the source node and temperature values at that particular time. This combo box will display the union of source time and analysis time values. The values displayed in the combo box will always be between the upper and lower bound values of the source time. If the user modifies the source time value, the selection will be preserved until the user modifies the value even if the step’s end time gets changed on the analysis settings object. If a new end time value is added/deleted, Source Time will get the value closest to the newly added Analysis time value.

5. Click on the imported load object, then right-click and select Import Load. This will interpolate the value at all the selected time steps. 6. User can display interpolated temperature values at different time steps by changing the Active Row option in the detail pane. 7. Apply required boundary conditions, continue with any further analysis and solve.

Mechanical-Electronics Interaction (Mechatronics) Data Transfer You can export a reduced model that can be imported into Simplorer.

Overall Workflow for Mechatronics Analysis 1. Create a modal analysis system. 2. Define the inputs using Remote Points and/or Named Selections. The names of the entities created must include the prefix input_ and the degree of freedom in the trailing suffix, signified by an underbar (e.g. «input_MyName_ux»).

Note The Named Selection can only be scoped to a vertex.

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Special Analysis Topics 3. Define the outputs using Named Selection. The names of the entities created must include the prefix output_ and the degree of freedom in the suffix (e.g. «output_MyName2_rotx”).

Note The Named Selection can only be scoped to a vertex.

4. Specify the modal damping in a Commands Object under an Environment, e.g.: dmprat,.02 mdamp,1,.05

! 2% damping on all modes ! 5% damping on mode 1

5. At Solution level, add a Commands Object and import the macro ExportStateSpaceMatrices.mac to export the reduced model. It is located at the installation folder under: ANSYS Inc\v121\AISOL\DesignSpace\DSPages\macros

Note The macro is based on the APDL command SPMWRITE.

6. Solve the Modal Analysis. 7. The reduced model file (file.spm) and the graphics file (file_spm.png) will exist in the solver files directory and can then be imported into Simplorer. (See Project File Management in Workbench User’s Guide for more information on solver files directories.)

Set up the Mechanical Application for Export to Simplorer To set up the Mechanical application to retrieve the inputs and outputs defined so they can be used in the reduced model exported to Simplorer: 1. From the Tools menu in the Mechanical application, select Variable Manager. 2. In the Variable Manager window, add/activate the variable ExportToSimplorer and set it to 1.

Polyflow to Mechanical Data Transfer This feature enables you to import data from a Polyflow system and apply it in a Mechanical application analysis. Temperature data can be imported into a static structural, transient structural1 steady-state thermal, transient thermal or thermal-electric analysis. To import data from a Polyflow system: • In the Project Schematic, right-click the Solution cell of the Polyflow system and select Transfer Data to New><mechanical system>, a link is created to the Model cell of the selected Mechanical system. If you select Transfer Data to New > <mechanical system>, this operation automatically creates a link to the Model cell of the Mechanical system. Alternatively, you can drag the Solution cell of the Polyflow system and drop it onto the Model cell of a Mechanical system to create the link.

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Analysis Types • To transfer temperature data to Mechanical, drag the Solution cell of the Polyflow system and drop it onto the Setup cell of an applicable Mechanical system. • To transfer thickness data to Mechanical, drag the Solution cell of the Polyflow system and drop it onto the Model cell of an applicable Mechanical system. If your simulation has thickness defined from a Polyflow system, an Imported Thickness folder is added under the Geometry folder. 1.

Select appropriate geometry in the Details view, and then click Apply.

2.

Select appropriate options in the Details view. You can modify the mapping settings to achieve the desired mapping accuracy.

3.

You can specify a thickness value for the unmapped target nodes using the Unmapped Data Value property. By default, a zero thickness value is assigned to the unmapped nodes.

Important For the ANSYS solver, the thickness value at each node must be greater than zero.

4.

Right-click the Imported Thickness object, and then click Import Thickness to import the thickness. When the thickness has been imported successfully, a contour plot will be displayed in the Geometry window and any mesh display will be based upon the mapped thickness of the elements.

If your simulation has temperature data defined from a Polyflow system, an Imported Load folder is added under the Environment folder. 1.

To add an imported temperature load, click the Imported Load folder to make the Environment toolbar available, or right-click the Imported Load folder and select the appropriate load from the context menu.

2.

Select appropriate geometry in the Details view, and then click Apply.

3.

In a 3D structural analysis, if the Imported Body Temperature load is scoped to one or more surface bodies, the Shell Face option in the details view enables you to apply the temperatures to Both faces, to the Top face(s) only, or to the Bottom face(s) only. See Imported Body Temperature for additional information.

4.

Select appropriate options in the Details view. You can modify the mapper settings to achieve the desired mapping accuracy. • In a 3D analysis, if the Triangulation mapping algorithm is used, the Transfer Type mapping option defaults to Surface when an Imported Temperature or Imported Body Temperature load scoping is only on shell bodies. If the scoping is on shell bodies and other geometry types, the Transfer Type mapping option will default to Volumetric. In such cases, to obtain a more accurate mapping, you should create a separate imported load for geometry selections on shell bodies, and use the Surface option for Transfer Type.

5.

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Under Data View, select the desired data Identifier, for the imported load. The data identifier (File Identifier: Data Identifier) strings are specified by the upstream Polyflow system. You can also change the Analysis Time and specify Scale and Offset values for the imported loads. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

Special Analysis Topics 6.

Right-click in the Data View and select Add row to specify additional data for a different analysis time.

7.

In the project tree, right-click the Imported Load object, and then click Import Load to import the load. When the load has been imported successfully, a contour plot will be displayed in the Geometry window.

8.

If multiple rows are defined in the Data View, imported values at different time steps can be displayed by changing the Active Row option in the details pane.

9.

Change any of the columns in the Data View tab as needed: • Magnitude Select the appropriate data identifier that represents the load values to be applied from the drop down list. • Analysis Time Choose the analysis time at which the load will be applied. For the ANSYS solver, this must coincide with the end time of a step defined in the Analysis Settings object in the tree. • Scale The amount by which the imported load values are scaled before applying them. • Offset An offset that is added to the imported load values before applying them.

10. To activate or deactivate the load at a step, highlight the specific step in the Graph or Tabular Data window, and choose Activate/Deactivate at this step! See Activation/Deactivation of Loads for additional rules when multiple load objects of the same type exist on common geometry selections.

Simplorer/Rigid Dynamics Co-Simulation This feature is a co-simulation link (transient-transient) between Simplorer and the ANSYS Rigid Dynamics solver. This link enables you to combine detailed rigid mechanics models with system models such as complex electronic semiconductor device models used in controls. You can export a rigid dynamics sub-circuit and perform an analysis of the structure in Simplorer. • Simplorer and rigid dynamics models are connected by Simplorer Pins (p. 329). • Simulation is driven by Simplorer. • Results can be reviewed in Simplorer, and then imported back to ANSYS Mechanical.

Preparing the Analysis Create a Rigid Dynamics Analysis System Basic general information about this topic Define Engineering Data

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Analysis Types Basic general information about this topic … for this analysis type: Density is the only material property utilized in a rigid dynamics analysis. Models that use zero or nearly zero density fail to solve using the ANSYS Rigid Dynamics solver. Attach Geometry Basic general information about this topic … for this analysis type: Only sheet and solid bodies are supported by the ANSYS Rigid Dynamics solver. Plane bodies and line bodies cannot be used. Define Part Behavior Basic general information about this topic … for this analysis type: You can define a Point Mass for this analysis type. Part stiffness behavior is not required for the ANSYS Rigid Dynamics solver in ANSYS Workbench. Define Joints and Springs Basic general information about this topic … for this analysis type: Applicable connections for this type of analysis are joints or springs. When an assembly is imported from a CAD system, joints and constraints are not imported; however, joints can be created automatically or manually after the model has been imported. Each joint is defined by its coordinate system of reference. The orientation of this coordinate system is essential, as free and fixed degrees of freedom are defined in this coordinate system. Contact is not supported for this analysis type. Define Input and Output Pins Basic general information about this topic … for this analysis type: The quantities that are driven by Simplorer are defined as input pins. The quantities that are monitored by Simplorer are defined as output pins. Define Analysis Settings

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Special Analysis Topics Basic general information about this topic … for this analysis type: Some of the analysis settings might be overwritten by those defined in Simplorer, because Simplorer drives the co-simulation.

Simplorer Pins Simplorer Pins are connection points that describe the interface between a rigid dynamics model and a Simplorer model. Pins have two distinct natures: • Input Pins are used by Simplorer to drive the rigid dynamics model. • Output Pins are sensors used by Simplorer to monitor the rigid dynamics model state. Pins are defined by the degrees of freedom of joints. One pin can be attached to each degree of freedom of a joint. The type of joint quantity attached to pin depends on the nature of the degrees of freedom. Translational degrees of freedom can have Displacement, Velocity, Acceleration, and Force pins. Rotational degrees of freedom can have Rotation, Angular Velocity, Angular Acceleration, and Moment pins.

Note It is not recommended that you place additional joint conditions on degrees of freedom that are associated with pins. To create pins for a Rigid Dynamics analysis system: 1.

Open a Rigid Dynamics analysis system in Workbench, then double-click on the Model field to open the model for editing in the Mechanical application.

2.

In the Mechanical application tool bar, click the New Simplorer Pin button as shown below to add a new pin. If you click the New Simplorer Pin button while a joint is selected, the pin will automatically have joint information associated with it. If no joint is selected, you will need to associate the pin with a joint at a later time.

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Analysis Types

3.

With the new pin selected in the Outline view, edit the DOF, Type, and Pin Nature fields in the Details view to complete the pin setup.

4.

Rename the pin as it should appear in Simplorer.

5.

Repeat steps 2, 3, and 4 to add all pins of interest.

6.

When finished adding pins, refer to Set up the Mechanical Application for Export to Simplorer (p. 325) for more information.

Static Analysis From Rigid Dynamics Analysis You can perform a Rigid Dynamics Analysis (p. 216) and then change it to a Static Structural Analysis (p. 272) for the purpose of determining deformation, stresses, and strains — which are not available in the Rigid Dynamics analysis.

Creating an Analysis System 1. From the toolbox, drag and drop a Rigid Dynamics template onto the project schematic. Follow the procedure for creating a rigid dynamics analysis. Apply forces and/or drivers, and insert any valid solution result object(s). 330

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Special Analysis Topics 2. Specify the time of interest in the tabular data table or in the Graph window. 3. Select a solution result object and click the right mouse to display the popup menu. Select Export Motion Loads and specify a load file name. 4. In the project schematic, duplicate the Rigid Dynamics analysis system. Replace the duplicated analysis system with a Static Structural analysis system.

Note If you do not need to keep the original Rigid Dynamics analysis, you can replace it with the Static Structural analysis system.

5. Edit the Static Structural analysis (using Model, Edit) by suppressing all parts except the desired part for the Static Structural analysis. 6. Change the Stiffness Behavior of the part to be analyzed from Rigid to Flexible. 7. Change mesh solver preference to be ANSYS Mechanical instead of ANSYS Rigid Dynamics. 8. Delete or suppress all loads used in the Rigid Dynamics analysis. 9. Import the motion loads that were exported from the Rigid Dynamics analysis. Highlight the Static Structural branch and then right mouse click, Insert> Motion Loads….

Note Moments and forces created for the static structural analysis can be in an invalid state if all three components of the force/moment are almost equal to zero.

10. Delete the result objects and add new ones. 11. Solve the single part model with the static structural analysis and evaluate the results.

Point to Remember It is important that you create the Static Structural analysis after the Rigid Dynamics analysis is finished and the export load is done.

Submodeling Submodeling is a finite element technique that you can use to obtain more accurate results in a particular region of a model. A finite element mesh may be too coarse to produce satisfactory results in a given region of interest. The results away from this region, however, may be satisfactory. Reanalyzing the entire model using a greater mesh refinement in order to obtain more accurate results in one particular region is time-consuming and costly. Instead, you can use submodeling to generate an independent, more finely meshed model of only the region (submodel) of interest and then analyze it. The following submodeling topics are available: Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types Understanding Submodeling Structural Submodeling Workflow Thermal Submodeling Workflow

Understanding Submodeling In finite element analysis, the finite element mesh is sometimes too coarse to produce satisfactory results in a specific region of interest, such as a stress concentration region in a stress analysis as shown in the figure that follows. The figure illustrates how to deal with the problem by using submodeling to create a finer mesh on the region (submodel) of interest. Figure 14: Submodeling of a Pulley

Submodeling of a pulley hub and spokes: (a) coarsely meshed model, and (b) finely meshed submodel (shown superimposed over coarse model) Submodeling is also known as the cut-boundary displacement method or the specified boundary displacement method. The cut boundary is the boundary of the submodel which represents a cut through the coarse model. Displacements calculated on the cut boundary of the coarse model are specified as boundary conditions for the submodel. Submodeling is based on St. Venant’s principle, which states that if an actual distribution of forces is replaced by a statically equivalent system, the distribution of stress and strain is altered only near the regions of load application. The principle implies that stress concentration effects are localized around the concentration; therefore, if the boundaries of the submodel are far enough away from the stress concentration, reasonably accurate results can be calculated in the submodel. The Mechanical application allows submodeling for structural (stress) and thermal analyses. In a thermal analysis, the temperatures calculated on the cut boundary of the coarse model are specified as boundary conditions for the submodel. Aside from the obvious benefit of yielding more accurate results in a region of your model, the submodeling technique has other advantages: • It reduces, or even eliminates, the need for complicated transition regions in solid finite element models. • It enables you to experiment with different designs for the region of interest (different fillet radii, for example).

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Special Analysis Topics • It helps you in demonstrating the adequacy of mesh refinements. The following restrictions apply to submodeling: • It is supported only for the MAPDL solver. • The principle behind submodeling assumes that the cut boundaries are far enough away from the stress concentration region. You must verify that this assumption is adequately satisfied.

Shell-to-Solid Submodels In the shell-to-solid submodeling technique, the coarse model is a shell model, and the submodel is a 3D solid model, as shown in this example: Figure 15: 3D Solid Submodel Superimposed on Coarse Shell Model

The procedure for shell-to-solid submodeling is essentially the same as that for solid-to-solid submodeling, with these exceptions: • Shell-to-solid submodeling submodeling is activated by setting the Transfer Key to Shell-Solid in the Imported Load details view. • Cut boundaries on the submodel are the end planes that are normal to the shell plane (see Figure 16: Node rotations (a) before mapping command, (b) after mapping command (p. 334)).

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Analysis Types • To determine the degree-of-freedom values at a cut-boundary node, the program first projects the node onto the nearest element in the shell plane. The degree-of-freedom values of this projected point are then calculated by interpolation and assigned to the corresponding node. • In a structural analysis, only translational displacements are calculated for the cut-boundary nodes, but their values are based on both the translations and rotations of the projected point. Also, the node is rotated such that the nodal UY direction is always perpendicular to the shell plane, as shown in Figure 16: Node rotations (a) before mapping command, (b) after mapping command (p. 334). A UY constraint is calculated only for nodes that are within 10 percent of the average shell element thickness from the shell plane, preventing overconstraint of the submodel in the transverse direction. Figure 16: Node rotations (a) before mapping command, (b) after mapping command

Nonlinear Submodeling For load-history-dependent problems (for example, when plastic materials exist), you must cut boundary conditions from the coarse model at multiple substeps to simulate the load history dependency in the fine-mesh model analysis. The more boundary cutting you do, the more accurate are the results of the fine-mesh model analysis.

Structural Submodeling Workflow This is the workflow for performing a submodeling analysis with linked structural systems: 1.

From the toolbox, drag and drop a transient or static structural template onto the project schematic. Perform all of the steps to set up and analyze the initial model. Specify mesh controls, boundary conditions, and solution settings as you normally would and solve the analysis. To easily identify this initial model, it is referred to as the coarse model. This does not mean that the mesh refinement is coarse, only that it is relatively coarse compared to the submodel.

2.

Drag-and-drop a Static Structural or Transient Structural template onto the project schematic. Share the Engineering Data and Geometry cells if required and then drag the Solution cell of the upstream onto the Setup cell of the downstream system.

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Special Analysis Topics

Note • You can add a template for the linked structural systems by creating your own template. • Data can be transferred from a 2D coarse model to a 3D submodel. The settings for 2D projection of target mesh nodes can be specified in Appendix C.

3.

Double-click the downstream systems Setup cell. In the Mechanical application, a Submodeling folder is automatically added into the system’s tree.

4.

To add an imported load, click the Submodeling folder to make the Environment toolbar available, or right-click the Submodeling folder and select the appropriate load from the context menu.

5.

Select appropriate cut-boundaries for transferring displacements or body selections for transferring temperatures in the Details view of the Imported Load object using the Geometry or Named Selection scoping option.

Note Mixing of scoping on surface bodies with other geometry types is not allowed. Nodal named selections are not valid for transferring temperatures in Shell-Shell submodeling.

6.

The Transfer Key is automatically selected in the details view based on scoping. For scoping on surface bodies, Shell-Shell Transfer Key is selected. For scoping on solids, Solid-Solid Transfer Key is selected by default. Change it to Shell-Solid for shell to solid submodeling.

7.

For Shell-Shell submodeling, the user has the option to import Displacements/Rotations/Both using the Sub Type property in the Details view.

8.

For Shell-Solid submodeling, the user has the option to import temperatures on Top/Bottom face or the Middle shell plane using the Shell Face option. The Top/Bottom option calculates and applies the temperatures on the top and bottom face independently, whereas the Middle option calculates the temperature at the middle shell plane and applies it across the thickness of the shell.

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Analysis Types 9.

For Shell-Shell submodeling, the user has the option to import temperatures from the Top/Bottom face or the Middle shell plane using the Shell Face option. The Top/Bottom option uses the temperature on both the top and bottom shell face to calculate the temperature on a target node, whereas the Middle option only uses the temperature at the middle shell plan.

10. When scoped on surface bodies, you can control the effective offset and thickness value at each target node of the surface bodies, and consequently the location used during mapping, by using the Shell Thickness Factor property. By default, the thickness value at each target node is ignored when data is mapped. You can choose to enter a positive or negative value for the Shell Thickness Factor. This value is multiplied by each target node’s physical thickness and is used along with the node’s offset to determine the top and bottom location of each target node. A positive value for the Shell Thickness Factor uses the top location of each node during mapping, while a negative value uses the bottom location of each node. For example: • A value of 0.0 means that the physical thickness and offset of the surface body nodes will be ignored; all target nodes are mapped at default surface body locations.

• A value of 1.0 means that the thickness used for a target node will be equal to the physical thickness value specified for that node. The top location of the node will be used during the mapping process.

• A value of –2.0 means that the thickness used for a target node will be equal to twice the physical thickness value specified for that node. The bottom location of the node will be used during the mapping process.

11. The Source Bodies option in the Details view allows you to select the bodies, from the upstream analysis, that make up the source mesh when mapping the data. You can choose one of the following options:

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Special Analysis Topics • All: The source mesh in this case will comprise of all the bodies that were used in upstream analysis. For cases where the source values are significantly different at the boundaries across two or more bodies, the interpolation may need to be performed separately on each geometry to ensure that the mapped values match the source. • Manual: This option enables you to select one or more source bodies to make up the source mesh. The source body selections are made in the Material IDs field by entering the material IDs that correspond to the source bodies that you would like to use. Type material IDs and/or material ID ranges separated by commas to specify your selection. For example, type 1, 2, 5-10. The material IDs for the source bodies can be seen in the Solution Information Object of the source analysis. In the example below, text is taken from a solver output: ***********Elements for Body 1 «coil» *********** ***********Elements for Body 2 «core» *********** ***********Elements for Body 3 «bar» ************

The body ‘coil’ has material ID 1, body ‘core’ has material ID 2, and body ‘bar’ has material ID 3.

Note For Shell-Shell and Shell-Solid Transfer Key, only shell bodies are selected from the upstream analysis. For Solid-Solid Transfer Key, the values on the middle shell plane of shell bodies are used for mapping.

12. You can transform the source mesh used in the mapping process by using the Rigid Transformation properties. This option is useful if the source geometry was defined with respect to a coordinate system that is not aligned with the target geometry system. 13. For each load step, if an Imported Displacement and other support/displacement constraints are applied on common geometry selections, you can choose to override the specified constraints by using the Override Constraints option in the details of the Imported Displacement object. By default, the specified constraints are respected and imported displacements/rotations are applied only to the free degrees of freedom of a node. 14. Change any of the columns in the Data View tab as needed: • Source Time: The time at which the data will be imported from the coarse analysis. • Analysis Time: Choose the analysis time at which the load will be applied.

Note The Data View can automatically be populated with the source and analysis times using Source Time property in the Details View. Use All to import data at all times in the source analysis, or Range to import data for a range specified by a Minimum and a Maximum.

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Analysis Types 15. You can define multiple rows in the Data View tab to import source data at multiple times and apply them at different analysis times. If multiple rows are defined in the Data View, it is possible to preview imported load vectors/contour applied to a given row or analysis time in the Data View. Choose Active Row or Analysis Time using the By property under Graphics Controls in the details of the imported load and then specify the Active Row/Analysis Time to preview the data.

Note If the Analysis Time specified by the user does not match the list of analysis times in the Data View, the data is displayed at the analysis time closest to the specified time.

16. You can modify the Mapper Settings to achieve the desired mapping accuracy. Mapping can be validated by using Mapping Validation objects.

Note Mapping Validation is not supported for Shell-Solid Transfer Key.

17. Right-click the Imported Load object and click Import Load to import the load. When the load has been imported successfully, a plot of the mapped values will be displayed in the Geometry window. For displacement loads, the following data is available for viewing. • Displacement • Rotations (For Shell-Shell Transfer Key only) When multiple data types are available for viewing, the appropriate data type can be chosen in the Data field under Graphics Controls. Contours plots of the magnitude (Total) or X/Y/Z component can be viewed by changing the Vector Component option in the details pane. Defaults to a vector plot (All).

Note The range of data displayed in the graphics window can be controlled using the Legend controls options. See Imported Boundary Conditions for additional information. For temperature loads on bodies, a Shell Face option is available under Graphics Controls for Shell-Shell Transfer Key. It allows you to view the data on top, middle or the bottom face of the shell. • The data displayed on the middle face is calculated by averaging the interpolated data on the top and bottom face. 18. To activate or deactivate the load at a step, highlight the specific step in the Graph or Tabular Data window, and choose Activate/Deactivate at this step!

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Special Analysis Topics See Activation/Deactivation of Loads for additional rules when multiple load objects of the same type exist on common geometry selections. 19. Define any other loads and boundary conditions, specify load step options, and obtain the submodel solution. 20. The final step is to verify that the cut boundaries of the submodel are far enough away from the concentration. You can do this by comparing results (stresses and so on) along the cut boundaries with those along the corresponding locations of the coarse model. If the results are in good agreement, it indicates that proper cut boundaries have been chosen; otherwise, you will need to recreate and reanalyze the submodel with different cut boundaries further away from the region of interest. For more information, see Imported Displacement and Imported Body Temperature.

Thermal Submodeling Workflow This is the workflow for performing a submodeling analysis with linked thermal systems: 1.

From the toolbox, drag and drop a transient or steady-state thermal template onto the project schematic. Perform all of the steps to set up and analyze the initial model. Specify mesh controls, boundary conditions, and solution settings as you normally would and solve the analysis. To easily identify this initial model, it is referred to as the coarse model. This does not mean that the mesh refinement is coarse, only that it is relatively coarse compared to the submodel.

2.

Drag-and-drop a Steady-State Thermal or Transient Thermal template onto the project schematic. Share the Engineering Data and Geometry cells if required and then drag the Solution cell of the upstream onto the Setup cell of the downstream system.

Note • You can add a template for the linked thermal systems by creating your own template. • Data can be transferred from a 2D coarse model to a 3D submodel. The settings for 2D projection of target mesh nodes can be specified in Appendix C.

3.

Double-click the downstream systems Setup cell. In the Mechanical application, a Submodeling folder is automatically added into the system’s tree.

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Analysis Types 4.

An imported temperature object is automatically inserted under the Submodeling folder to represent the transfer. To add additional Imported Temperature objects, click the Submodeling folder to make the Environment toolbar available, or right-click the Submodeling folder and select the appropriate load from the context menu.

5.

Select appropriate cut-boundaries for transferring temperatures or body selections for transferring temperatures in the Details view of the Imported Load object using the Geometry or Named Selection scoping option.

Note Mixing of scoping on surface bodies with other geometry types is not allowed.

6.

The Transfer Key is automatically selected in the details view based on scoping. For scoping on surface bodies, Shell-Shell Transfer Key is selected. For scoping on solids, Solid-Solid Transfer Key is selected by default. Change it to Shell-Solid for shell to solid submodeling.

7.

The Source Bodies option in the Details view allows you to select the bodies, from the upstream analysis, that make up the source mesh when mapping the data. You can choose one of the following options: • All: The source mesh in this case will comprise of all the bodies that were used in upstream analysis. For cases where the source values are significantly different at the boundaries across two or more bodies, the interpolation may need to be performed separately on each geometry to ensure that the mapped values match the source. • Manual: This option enables you to select one or more source bodies to make up the source mesh. The source body selections are made in the Material IDs field by entering the material IDs that correspond to the source bodies that you would like to use. Type material IDs and/or material ID ranges separated by commas to specify your selection. For example, type 1, 2, 5-10. The material IDs for the source bodies can be seen in the Solution Information Object of the source analysis. In the example below, text is taken from a solver output: ***********Elements for Body 1 «coil» *********** ***********Elements for Body 2 «core» *********** ***********Elements for Body 3 «bar» ************

The body ‘coil’ has material ID 1, body ‘core’ has material ID 2, and body ‘bar’ has material ID 3.

Note For Shell-Shell and Shell-Solid Transfer Key, only shell bodies are selected from the upstream analysis. For Solid-Solid Transfer Key, the values on the middle shell plane of shell bodies are used for mapping.

8.

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You can transform the source mesh used in the mapping process by using the Rigid Transformation properties. This option is useful if the source geometry was defined with respect to a coordinate system that is not aligned with the target geometry system.

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Special Analysis Topics 9.

When scoped on surface bodies, you can control the effective offset and thickness value at each target node of the surface bodies, and consequently the location used during mapping, by using the Shell Thickness Factor property. See Structural Submodeling Workflow for more details.

10. Change any of the columns in the Data View tab as needed: • Source Time: The time at which the data will be imported from the coarse analysis. • Analysis Time: Choose the analysis time at which the load will be applied.

Note The Data View can automatically be populated with the source and analysis times using Source Time property in the Details View. Use All to import data at all times in the source analysis, or Range to import data for a range specified by a Minimum and a Maximum.

11. You can define multiple rows in the Data View tab to import source data at multiple times and apply them at different analysis times. If multiple rows are defined in the Data View, it is possible to preview imported load vectors/contour applied to a given row or analysis time in the Data View. Choose Active Row or Analysis Time using the By property under Graphics Controls in the details of the imported load and then specify the Active Row/Analysis Time to preview the data.

Note If the Analysis Time specified by the user does not match the list of analysis times in the Data View, the data is displayed at the analysis time closest to the specified time.

12. You can modify the Mapper Settings to achieve the desired mapping accuracy. Mapping can be validated by using Mapping Validation objects.

Note Mapping Validation is not supported for Shell-Solid Transfer Key.

13. Right-click the Imported Load object and click Import Load to import the load. When the load has been imported successfully, a plot of the mapped values will be displayed in the Geometry window.

Note The range of data displayed in the graphics window can be controlled using the Legend controls options. See Imported Boundary Conditions for additional information.

14. To activate or deactivate the load at a step, highlight the specific step in the Graph or Tabular Data window, and choose Activate/Deactivate at this step!

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Analysis Types See Activation/Deactivation of Loads for additional rules when multiple load objects of the same type exist on common geometry selections. 15. Define any other loads and boundary conditions, specify load step options, and obtain the submodel solution. 16. The final step is to verify that the cut boundaries of the submodel are far enough away from the concentration. You can do this by comparing results (stresses and so on) along the cut boundaries with those along the corresponding locations of the coarse model. If the results are in good agreement, it indicates that proper cut boundaries have been chosen; otherwise, you will need to recreate and reanalyze the submodel with different cut boundaries further away from the region of interest. For more information, see Imported Temperature.

System Coupling System Coupling is an all-purpose infrastructure for tying two otherwise independent analyses together. In ANSYS Mechanical, you can use System Coupling to perform a fluid-structure interaction (FSI) analysis. For more information on FSI analyses, including methods other than System Coupling for performing them, see Fluid-Structure Interaction (FSI) (p. 317). You can perform a one-way or two-way fluid-structure interaction (FSI) analysis by connecting a Mechanical system and another participant system (such as Fluent) to a System Coupling component system. The Mechanical system (Static Structural, Transient Structural, Steady-State Thermal, or Transient Thermal) and other participant system are both dragged onto the Project Schematic from the Analysis Systems toolbox. The System Coupling component system is dragged onto the Project Schematic from the Component System toolbox. The participating systems are connected to the System Coupling component system (via the Setup cells). The following is the list of supported coupling participants: • Fluent • Static Structural • Transient Structural • Steady-State Thermal • Transient Thermal • External Data Thermal data can be transferred from another participant system to ANSYS Mechanical directly through System Coupling for one-way and two-way transfers. The coupling of the External Data system with System Coupling is a second method to set up a one-way, steady-state thermal transfer. When using the External Data system for one-way steady-state thermal coupling (for example, Fluent to Mechanical), an External Data and a Mechanical system are connected via the System Coupling system. The External Data system is used to gain access to the static ANSYS External Data (.axdt files) generated by Fluent or another solver, and the Mechanical system consumes these data. See Fluid-Structure Interaction (FSI) — One-Way Transfer Using System Coupling for more information. Once the participant systems are connected to the System Coupling component system, the System Coupling component system requests information from each. The information exchange includes system information (system type, units, file names, etc.), the number of coupling interface regions, and the 342

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Special Analysis Topics number and type of variables involved in the coupling. Once connected and set up, the System Coupling component system controls the solver execution for the Mechanical and the other participant system’s solver, and it manages the coupled-field analysis. Additional information can be found in the following sections: Supported Capabilities and Limitations Variables Available for System Coupling System Coupling Related Settings in Mechanical Fluid-Structure Interaction (FSI) — One-Way Transfers Using System Coupling Thermal-Fluid-Structural Analyses using System Coupling Restarting Structural Mechanical Analyses as Part of System Coupling Running Mechanical as a System Coupling Participant from the Command Line Troubleshooting Two-Way Coupling Analysis Problems Product Licensing Considerations when using System Coupling

Supported Capabilities and Limitations Mechanical supports the following capabilities when used in a System Coupling analysis: • Data exchange across the fluid-solid interface. The fluid-solid interface defines the interface between the fluid in the coupled participant system (for example, Fluent) and the solid in the Mechanical system. This interface is defined on regions in the Mechanical model (see Fluid Solid Interface (p. 782)). • Thermal-fluid-structural coupling between Mechanical and another participant system (for example, Fluent) is supported as an expert option, and requires the use of appropriate coupled field elements (SOLID226 and SOLID227). See Thermal-Fluid-Structural Analyses using System Coupling (p. 348) for details about how to set up this type of analysis. • Shared memory parallel mode. Note that convergence and therefore results will change between repeated runs of Mechanical in shared memory parallel mode. These changes will occur even if no setup changes were applied. The changes in the coupled analysis’ convergence and results are due to the segregated solution algorithm used and the inherent sensitivity of the coupled physics problems being solved. • Distributed parallel mode. Note that in order to run Mechanical in distributed parallel mode from within the Workbench interface, the working directory must be a shared network directory with the same path for all computer servers. Alternatively, the analysis can run in different working directories on all servers if Mechanical is run as a System Coupling Participant from the command line. For more information, see Running Mechanical as a System Coupling Participant from the Command Line (p. 352). • SOLID and SHELL elements. For a complete list of elements, see Load Transfer Coupled Analysis — Workbench: System Coupling in the Mechanical APDL Coupled-Field Analysis Guide. • Structural convergence information and Result Tracker information are provided to the System Coupling system for display in Chart Monitors. When using the Result Tracker in a System Coupling analysis, note that Kinetic Energy and Stiffness Energy are only computed at the end of a coupling step, and values of zero are reported for the intermediate coupling iterations. The Kinetic Energy and Stiffness Energy values reported in System Coupling are lagged, so the value reported at the start of a coupling step is actually the value corresponding to the end of the previous coupling step. The value corresponding to the last coupling step will not be reported in System Coupling.

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Analysis Types • Data transfer regions are the regions upon which the Fluid Solid Interface condition is applied. In a coupled analysis, at each data transfer region, only one type of variable can be sent, and one type of variable received. – In a coupled structural analysis, force and displacement can be transferred at data transfer regions. – In a coupled thermal analysis, heat transfer coefficients and near wall temperatures, temperatures, and heat flows can be transferred at data transfer regions. See Variables Available for System Coupling (p. 344) for more information about the variables transferred. Note the following limitations when using Mechanical in a System Coupling analysis: • System Coupling requires participants to use 3D meshes, with data transfer regions consisting of element faces within the 3D mesh. Data transfer regions cannot exist in 2D meshes (where the data transfer would be a line/curve). Line elements such as BEAM elements in Mechanical cannot form Data Transfer regions, but may be included elsewhere in the Mechanical model. • Using System Coupling with the Remote Solver Manager (RSM) is only supported in Mechanical for executions on a single local host. Note that System Coupling cannot participate in the update of design points through RSM. If Mechanical is set to run with RSM, you will get the following message: The solve process setting will use RSM. Coupled updates are only supported via RSM when the compute server is localhost. Coupled updates may fail if the compute server is a remote machine.

• In a System Coupling setup, if you apply an external force or external heat flow on the same region as a Fluid-Structure Interaction interface, this external variable will not be acknowledged by the Mechanical APDL solver. • When Mechanical participates in a System Coupling analysis only one load step can be defined in Mechanical. Loads can still vary as a function of time within this load step. Other operations that would normally require multiple load steps will require a System Coupling restart to be performed. For example, a prestressed analysis can be performed by executing a System Coupling simulation using the pre-stressing load conditions in Mechanical, then continuing the analysis by restarting System Coupling after making the necessary changes in Mechanical. • The Save Project Before Solution and Save Project After Solution properties of the Project object are not supported if you are using the Workbench System Coupling component system in combination with your Mechanical analysis.

Variables Available for System Coupling The following variables are available on all data transfer regions. Table 1: Variables On Boundary Wall Regions Display Name / Internal Name

Transfer Direction

Data Type

Physical Type

force / FORC

Input

VectorXYZ*

Force

displacement / INCD

Output

VectorXYZ*

Length

temperature / TEMP

Input and Output

Scalar

Temperature

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Special Analysis Topics Display Name / Internal Name

Transfer Direction

Data Type

Physical Type

heat flow / HFLW

Input and Output

Scalar

Heat Rate

heat transfer coefficient / HCOE

Input

Scalar

Heat Transfer Coefficient

near wall temperature / TBULK

Input

Scalar

Temperature

ur

ur * Represents the force vector

) respectively.

(

, , ) and the incremental displacements vector 

(

,

,

displacement In a general coupled analysis, when the solver receiving the motion (such as Fluent) solves before or simultaneously to the solver sending the motion (such as Mechanical), then the incremental displacement transferred during the first coupling iteration of each coupling step is identically zero. This behavior can be changed by using the expert setting GeneralAnalysis_IncrDisp_InitIterationValue_Zero, which is described in Expert Settings in the System Coupling User’s Guide. heat transfer coefficient Heat transfer coefficient is also known as “convection coefficient.” near wall temperature Near wall temperature is also known as “bulk temperature,” or “ambient temperature.”

Note The data plotted in the System Coupling Service’s chart monitors is provided by the coupling participants. For non-linear analyses, the structural convergence quantities from Mechanical are plotted in terms of the activated degrees of freedom in the structural solver. For the linear analyses, the structural convergence quantities from Mechanical are only plotted for thermal analysis with the temperature degrees of freedom.

System Coupling Related Settings in Mechanical End Time Specification For transient analyses, ANSYS Mechanical requires the end time specified in the setup to be respected. When coupling participants require their end time to be respected, the maximum allowable end time for the coupled analysis is the minimum of the end time specified by such participants. Other participant systems, such as Fluent, can run past the end time specified in the setup. These participant systems have no effect on the allowable end time of the coupled analysis.

Ramping of Data-Transfer Loads Mechanical has two types of ramping that can modify the loads obtained through data transfers in a coupled analysis. The two types of ramping are ramping over substeps, and ramping over coupling steps. The ramping on your load will be determined by the interaction of ramping settings you have Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types set between Mechanical as well as System Coupling. Both Mechanical ramping behaviors are controlled by the Solution Command Object KBC, which can be set to 1 or 0. In a steady-state analysis, the default setting is KBC = 0 (ramping on). In a transient analysis, the default setting is KBC = 1 (ramping off ). In System Coupling, substeps are unique to Mechanical, and are steps within a coupling iteration. Loads can be ramped over these substeps. The ramping factor applied to these loads is based on the number



of substeps,

. At the  substep, the ramping factor of   is applied. This ramping is based on the initial value of the load at the end of the last step. When KBC = 0 and  > , ramping over substeps occurs. If KBC = 1 or  = , ramping over substeps does not occur. In System Coupling, Mechanical has a second ramping option which ramps loads over the coupling steps. Regardless of what other ramping settings are on, System Coupling always transfers the full load at the end of the coupling step, and then Mechanical applies a ramping factor to this full value at each coupling step. The ramping factor applied to the full load at the coupling step is based on the number



of coupling steps,  . At the  coupling step, the ramping factor of   is applied. When KBC = 0 and and  > , ramping over coupling steps occurs. If KBC = 1 or  = , ramping over coupling steps does not occur. Note that if you set ramping over coupling steps to occur in a transient analysis, loads received from System Coupling will be ramped over all coupling steps, and so the full load will only be applied at the last coupling step. This situation is not physical, but may still be useful when using a Transient Structural system to get steady-state results, for example when pre-stressing the structure for a further transient analysis.

Ramping of Loads Within Mechanical Loads within the Mechanical system (that is, loads that are not transferred to Mechanical through the coupled analysis) are ramped linearly using the Step End Time specified in Mechanical. In a steadystate coupled analysis, ramping of these loads is controlled by the relationship between the Step End Time specified in Mechanical, and the number of coupling steps specified in System Coupling. For a steady-state analysis, each coupling step in System Coupling corresponds to 1 s of time in Mechanical. • When the number of seconds set for the Step End Time in Mechanical equals the number of coupling steps set in System Coupling, the load is ramped linearly across all steps in the coupled analysis. • When the number of seconds set for the Step End Time in Mechanical is less than the number of coupling steps set in System Coupling, the load is ramped linearly to the coupling step that matches the end time, and then the full load is applied for the remaining steps. • When the number of seconds set for the Step End Time in Mechanical is more than the number of coupling steps set in System Coupling, the load is ramped linearly, but it will not reach its full value. The final value applied will be the ramped value that corresponds to the last coupling step, which may cause inaccuracies in your simulation. • If Mechanical’s Step End Time is set to 1s, this ramping will not occur. Note that Mechanical’s computational end time and its load-based end time are independent. The computational end time is equal to the number of coupling steps. The load-based end time controls the ramping behavior, and is set by the Step End Time option in the Mechanical Interface.

Output Controls When the Mechanical application is connected to System Coupling, behavior of the Output Controls is changed. For a normal Mechanical run, the «Store Results At» settings are applied per step and «Specified

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Special Analysis Topics Recurrence Rate» is defined as the output frequency within a step at some substep frequency. When the Mechanical application is connected to System Coupling, these settings are applied across all steps, not within one step. This means that you cannot output results within a step. System Coupling simulations may run many steps, so these settings should be used to reduce the results frequency as needed. For more information on using the Mechanical application for FSI analyses, see Fluid-Structure Interaction (FSI) (p. 317).

Fluid-Structure Interaction (FSI) — One-Way Transfers Using System Coupling The System Coupling approach may be used to transfer force into, structural data out of, or thermal data into or out of the Mechanical analyses. In some cases, System Coupling is an alternative to transferring data using Imported Loads. System Coupling is particularly useful as a first step in a sequence of coupled analyses that may advance to co-simulation involving two-way transfers. In all cases, begin by defining a Fluid Solid Interface boundary condition at the location corresponding to the fluid-structure interface.

Transferring Data Into Mechanical Analyses When the External Data system is connected to the Mechanical system via System Coupling, Mechanical is given access to static data from .axdt files. When a co-simulation coupling participant, such as the ANSYS Fluent system, is connected to the Mechanical system via System Coupling, Mechanical is given access to data directly from the other participant. To start the setup of the coupled analysis, link the Setup cell from the Mechanical system to the Setup cell in the System Coupling system. See System Coupling for more information. In a one-way coupled analyses, you can transfer steady-state or transient thermal data (temperature, heat flow, or heat transfer coefficient and near wall temperature), or force (from CFD pressures and viscous forces) to the Mechanical system. To transfer data from a co-simulation participant directly through System Coupling, connect a co-simulation compatible coupling participant, (such as the Fluent, Steady-State Thermal, or Transient Thermal system), to the System Coupling system that is connected to your Static or Transient Structural system. In the System Coupling system, define the desired data transfers from the other coupling participant to your Mechanical system. To transfer static data into Mechanical, an External Data system is connected to the System Coupling system. Transferring data using the External Data system is useful when people with different licenses are working on the same project. To use the External Data system, connect the External Data system to the System Coupling system that is connected to your thermal or fluid system. In the External Data system, select one or more ANSYS External Data files (with an .axdt extension). In the System Coupling system, define the desired data transfers from the External Data coupling participant to the Mechanical coupling participant. The ANSYS External Data text-formatted files can be generated by the CFD-Post component system from another participant’s (such as Fluent’s) analysis results. This method is demonstrated in Tutorial: Heat Transfer from a Heating Coil in the System Coupling User’s Guide.

Transferring Data Out of Mechanical Analyses The System Coupling system is also able to provide other coupling participants with access to data from the Mechanical system. Data transfers out of Mechanical are available directly through the System Coupling system. In these coupled analyses, you can transfer displacement or thermal data (temperature or heat flow) from Mechanical. To set up this transfer, link your Static or Transient Structural system and another compatible Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types coupling participant, (such as the Fluent, Steady-State Thermal, or Transient Thermal system), to a System Coupling system. In the System Coupling system, define the desired data transfers from the Mechanical system to the other co-simulation coupling. To transfer static data, the External Data system using ANSYS External Data files (with an .axdt extension) can also be used. These files are automatically output in the Mechanical solver files directory when you set the Export Results property of the Fluid Solid Interface to Yes. Transferring data using the External Data system is useful when people with different licenses are working on the same project. In a thermal coupled analysis, if you are running Mechanical through the command line, you need to add the macro dumpFSIHeats.mac to your MAPDL running directory in order to export static data into an axdt file. This macro is available from C:\Program Files\ANSYS Inc\v150\aisol\DesignSpace\DSPages\macros, and should be added to your MAPDL directory before running Mechanical through the command line. To transfer static Mechanical data (in the .axdt file) into an External Data system, introduce an External Data system into your schematic, edit the External Data Setup, and select one or more of the ANSYS External Data files. For more detail, see the Export Results in the Detail View Properties of the Fluid Solid Interface (p. 782) section of the “Setting Up Boundary Conditions” chapter. One of these .axdt files is created for each Fluid Solid Interface boundary condition, and each file may contain temperatures and heat flows. Only corner node values for temperatures and heat flows are recorded in the .axdt file (mid-side noded heat flow values, if present, are summed to the corresponding corner nodes). The heat flow data includes the sum of heat flows through surfaces with applied temperatures, convections and radiation. Finally, link the External Data system’s Setup cell to the System Coupling system’s Setup cell, and define the desired data transfer in the System Coupling setup. The Tutorial: Heat Transfer from a Heating Coil in the System Coupling User’s Guide provides a detailed overview of a coupled analysis using Mechanical, System Coupling, and the External Data system.

Thermal-Fluid-Structural Analyses using System Coupling Thermal-fluid-structural coupling between Mechanical and another participant system (such as Fluent) are supported, with an expert option used in Mechanical to enable the data transfers. For this analysis, the Mechanical model needs to be created using the Static Structural or Transient Structural system, and you also need to use the appropriate Coupled Field Elements (SOLID226 and SOLID227). To do a thermal-fluid-structural analysis, in Mechanical’s Details of “Fluid Solid Interface”, you have to set Definition>Data to Transfer [Expert]>System Coupling Data Transfers. This expert setting allows the fluid solid interface regions to participate in force, displacement, and thermal couplings through the System Coupling service. For a thermal-fluid-structural analysis, the coupled field elements SOLID226 and SOLID227 (KEYOPT(1)=11) need to be used in Mechanical because they have the appropriate degrees of freedom. The element SOLID226 replaces any SOLID186, and the element SOLID227 replaces any SOLID187. To select the proper coupled field elements into your structural analysis, follow these steps to insert the correct Commands objects: 1. In your Workbench Project Schematic, update your structural system’s Setup cell and locate the ds.dat file. Or, you can use Tools>Write Input File to write out this file. 2. Open the ds.dat file in a text editor and search for “et,” to locate the element types for each body. In the example below, the body named «fea» has SOLID186 elements. Bodies may have more than one element type («fea» may also contain SOLID187). Make sure to keep searching until you have identified all of the element types associated with each solid body. 348

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Special Analysis Topics Figure 17: Example of a search for element types in a ds.dat file

3. In Mechanical’s Outline tree, below Geometry, right-click the solid body and insert a Command. Add the appropriate ET commands under each solid body, replacing SOLID186 with SOLID226, and SOLID187 with SOLID227. For the case shown in Figure 18: Example of element types in multiple solid bodies (p. 349), the commands that you would use for each body are: • For Body 1 “Pipe”, the command is: et,matid,226,11 • For Body 2 “Clamp”, the command is: et,matid,227,11 and et,matid+1,226,11 • For Body 4 “Support”, the command is: et,matid,226,11 Note that matid and matid+1 are used to refer to the element type number. Figure 18: Example of element types in multiple solid bodies

4. In the Outline tree, below Static or Transient analysis, insert a Commands object to define the thermal boundary conditions. 5. Create Named Selections for regions that require thermal boundary conditions, then refer to these named selections in the Commands object that you created in step 4. Within your Commands, the IC Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types command sets the initial temperature. The SF command is used to define convection, heat flux, and radiation loads. The D command is used to set a temperature constraint on the named selection. In your thermal-fluid-structural analysis using coupled field elements: • be careful if you change units, as the commands may need to be changed too. • use a zero displacement constraint rather than any fixed supports. A fixed support sets all of the degrees of freedom (DOF) to zero, including the thermal DOF for coupled field elements. • make sure the initial temperature is set correctly. In Mechanical’s Outline tree, under Details of “Transient”, the value set in Options>Environment Temperature defines the temperature at which there is zero thermal stress. The initial temperature defaults to this Environment Temperature. To define a different initial temperature, use the IC command within your command object created in step 4 above.

Restarting Structural Mechanical Analyses as Part of System Coupling Go to the section Restarting a System Coupling Analysis in the System Coupling User’s Guide for the steps needed to restart a coupled analysis. To restart your coupled analysis, you will also need restart information specific to the participants connected to your System Coupling system. For other participant systems connected to your System Coupling system, see Supported System Couplings in the System Coupling User’s Guide for a list of supported systems and references to their corresponding documentation regarding restarts. The sections below have information specific to restarting Mechanical in a coupled analysis: Generating Mechanical Restart Files Specifying a Restart Point in Mechanical Making Changes in Mechanical Before Restarting Recovering the Mechanical Restart Point after a Workbench Crash

Note • When using restarts with System Coupling, turn off the Pre-load the Mechanical editor option. Turning off this option will ensure that the state of the Mechanical system is correctly updated. • No restarting is supported for coupled analyses which include Mechanical’s Steady-State Thermal or Transient Thermal systems.

Generating Mechanical Restart Files Restarts of a system coupling analysis requires corresponding restart points to exist in the coupling service and in each of the solvers participating in the analysis. In order to generate the restart files in Mechanical (rdb/rXXX files), you need to: 1.

In the Mechanical interface, select Analysis Settings.

2.

In Details of «Analysis Settings», ensure that Restart Controls > Retain Files After Full Solve setting is set to Yes.

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Special Analysis Topics

Specifying a Restart Point in Mechanical The restart point selected in the Mechanical solver must be consistent with the restart points selected for the System Coupling service and other coupling participants. A run-time error will be issued if an analysis is restarted with incompatible time points. To specify a restart point in Mechanical, perform the following steps: 1.

Double-click the Mechanical’s Solution cell in Workbench.

2.

In the Outline view tree, select Analysis Settings.

3.

In the Details of Analysis Settings”, under Restart Analysis, set Restart Type to Manual and select the correct restart point from the drop-down menu of Current Restart Point.

4.

Close the Mechanical application.

5.

In the Project Schematic, right-click Mechanical system’s Setup cell and select Update.

Making Changes in Mechanical Before Restarting In some cases, setup changes are desired or are required to avoid failure of the coupled analysis. To modify settings in Mechanical: 1.

If the Mechanical interface is not already open, in the Project Schematic, double-click Mechanical’s Solution cell.

2.

Modify the needed settings in Mechanical.

3.

Save the project and close the Mechanical application. All of the setup changes will be applied for the subsequent coupled analyses.

Note The modification of some settings in Mechanical may invalidate and cause the deletion of all restart points. This deletion of restart points can cause the runtime error which warns of incompatible restart points. Save your project before modifying any settings in Mechanical so that if needed, you are able to restore the saved project and any deleted restart points.

Recovering the Mechanical Restart Point after a Workbench Crash Workbench or one of the components may crash such that restart files are available but they are not recognized or populated in the Workbench project. If this is the case, you will be able to recover your project and restart your analysis. See Recovering from a Workbench Crash in the System Coupling User’s Guide for the steps needed to recover a coupled analysis after a Workbench crash. You will also need the information below about Mechanical, as well as information specific to the other participant systems connected to System Coupling. For other participant systems connected to your System Coupling system, see Supported System Couplings in the System Coupling User’s Guide for a list of supported systems and references to their corresponding documentation regarding restarts.

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Analysis Types The _ProjectScratch directory is a temporary directory used by the MAPDL solver. This directory contains the latest structural results and restart points written during the System Coupling run before Workbench crashed. Mechanical will need to read these file to recover the project using the steps below. Note that the .backup directory contains the original version of any files which have been modified since the last save. These files are useful to recover the last saved state, but they are not useful for restarting your analysis. To recover Mechanical’s restart point after a workbench crash: 1.

In the Project Schematic, double-click Mechanical’s Setup cell. In the Mechanical interface, select the Solution entry from the tree.

2.

From the main menu, select Tools > Read Result Files.

3.

Browse into the _ProjectScratch directory and select file.rst. Mechanical will now patch itself into a state consistent with the results files, with restarts points (if they were written) available for selection in Mechanical.

4.

Select the restart point in Mechanical as in Specifying a Restart Point in Mechanical (p. 351) above.

5.

Once you have selected Mechanical’s restart point, in the Project Schematic, right-click Mechanical’s Setup cell and select Update.

Running Mechanical as a System Coupling Participant from the Command Line System Coupling analyses can be run via the command line (described in Executing System Couplings Using the Command Line in the System Coupling User’s Guide). To run Mechanical as a coupling participant, execute the following steps: • Complete the System Coupling–related settings in Mechanical (see System Coupling Related Settings in Mechanical (p. 345)) • Write the Mechanical APDL application input file: – Highlight the Solution object folder in the tree – From the Main Menu, choose Tools>Write Input File… – In the Save As dialog box, specify a location and name for the input file • Start the coupling service and obtain the following information from the System Coupling Server (SCS) file: – the port and host on which the service is being run, and – the identifier (or name) for Mechanical • Use this SCS information to set the Mechanical–specific system coupling command line options (described in Starting an ANSYS Session from the Command Level in the Operations Guide). • Note that for System Coupling cases run on Linux, when you launch MAPDL from the command line, you need to be careful about the participant name that you use. You may need to escape the quotes or the space if a name with a space, such as «Solution 1», is used for MAPDL. For example, appropriate text in the command line is:

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Special Analysis Topics – ansys150.exe -scname=\»Solution 1\» or – ansys150.exe -scname=»Solution\ 1″

Troubleshooting Two-Way Coupling Analysis Problems The following files, found in the Mechanical run directory (SYS/MECH under a Workbench design point directory), may prove useful in troubleshooting coupled analysis problems: • file.err: This file contains a summary of all of the errors that occurred during the run. • solve.out (or other output file): This file contains a complete summary of the current/latest run’s evolution. This is one of the most useful files to determine why the coupled analysis failed. To generate extensive debug output during the analysis, enter the following command as a command snippet in the analysis branch when completing the Mechanical problem setup: /debug,-1,,,,,2

Provide all of these files when submitting a request for service to ANSYS personnel.

Product Licensing Considerations when using System Coupling The licenses needed for Mechanical as part of a System Coupling analyses are listed in the table below. Additional licenses may be required for other participant systems in the coupled analysis, but no additional licenses are required for the System Coupling infrastructure itself. The simultaneous execution of coupling participants currently precludes the use of the license sharing feature that exists for some product licenses. The following specific requirements consequently exist: • Distinct licenses are required for each coupling participant. • Licensing preferences should be set to ‘Use a separate license for each application’ rather than ‘Share a single license between applications when possible.’ The requirements listed above are particularly relevant for ANSYS Academic products. Table 2: Licenses required for Mechanical as part of a System Coupling analysis System

Commercial License Required

Academic License Required

Static Structural or Transient Structural

• ANSYS Structural,

• ANSYS Academic Associate,

• ANSYS Mechanical,

• ANSYS Academic Research,

• ANSYS Mechanical CFD-Flo,

• ANSYS Academic Research Mechanical,

• ANSYS Mechanical Emag, • ANSYS Multiphysics, • ANSYS Structural Solver, • ANSYS Mechanical Solver, or

• ANSYS Academic Teaching Advanced, • ANSYS Academic Teaching Introductory, or • ANSYS Academic Teaching Mechanical

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Analysis Types System

Commercial License Required

Academic License Required

• ANSYS Multiphysics Solver Steady-State Thermal or Transient Thermal

• ANSYS Mechanical,

• ANSYS Academic Associate,

• ANSYS Mechanical CFD-Flo,

• ANSYS Academic Research,

• ANSYS Mechanical Emag,

• ANSYS Academic Research Mechanical,

• ANSYS Multiphysics, • ANSYS Structural Solver,

• ANSYS Academic Teaching Advanced,

• ANSYS Mechanical Solver, or

• ANSYS Academic Teaching Introductory, or

• ANSYS Multiphysics Solver

• ANSYS Academic Teaching Mechanical

Thermal-Stress Analysis The Mechanical application allows you to apply temperatures from a thermal analysis as loads in a structural analysis for thermal stress evaluations. The load transfer is applicable for cases when the thermal and structural analyses share the mesh as well as for cases when the two analyses are solved using different meshes. For cases when the meshes are different, the temperature values are mapped and interpolated between the source and target meshes. Workflow for performing a thermal stress analysis with: • Shared Model 1. From the toolbox, drag and drop a transient or steady-state thermal template onto the project schematic. Perform all steps to set up a Steady-State Thermal or Transient Thermal. Specify mesh controls, boundary conditions, and solution settings as you normally would and solve the analysis. 2. Drag and drop a Static Structural or Transient Structural template on top of the thermal systems solution cell to enable the data transfer.

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Special Analysis Topics 3. Double-click the structural systems Setup cell. In the Mechanical application an Imported Body Temperature load is automatically added into the structural system’s tree under an Imported Load folder. 4. Select appropriate geometry in the Details view of the Imported Body Temperature object using the Geometry or Named Selection scoping option. If the load is scoped to one or more surface bodies, the Shell Face option in the details view allows you to apply the temperatures to Both faces, to the Top face(s) only, or to the Bottom face(s) only. See Imported Body Temperature for additional information. 5. Change any of the columns in the Data View tab as needed: – Source Time — The time at which the data will be imported from the coarse analysis. – Analysis Time — Choose the analysis time at which the load will be applied.

Note The Data View can automatically be populated with the source and analysis times using Source Time property in the Details view. Use All to import data at all times in the source analysis, or Range to import data for a range specified by a Minimum and a Maximum.

6. Right-click the Imported Body Temperature object and click Import Load to import the load. When the load has been imported successfully, a contour plot of the temperatures will be displayed in the Geometry window.

Note The range of data displayed in the graphics window can be controlled using the Legend controls options. See Imported Boundary Conditions for additional information.

7. You can define multiple rows in the Data View tab to import source data at multiple times and apply them at different analysis. If multiple rows are defined in the Data View, it is possible to preview imported load vectors/contour applied to a given row or analysis time in the Data View. Choose Active Row or Analysis Time using the By property under Graphics Controls in the details of the imported load and then specify the Active Row/Analysis Time to preview the data.

Note If the Analysis Time specified by the user does not match the list of analysis times in the Data View, the data is displayed at the analysis time closest to the specified time.

• Unshared Model 1. From the toolbox, drag and drop a steady-state or transient thermal template onto the project schematic. Perform all steps to set up a Steady-State Thermal or Transient Thermal. Specify mesh controls, boundary conditions, and solution settings as you normally would and solve the analysis.

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Analysis Types 2. Drag and drop a Static Structural or Transient Structural template onto the project schematic. Share the Engineering Data and Geometry cells if required and then drag the Solution cell of the thermal system onto the Setup cell of the structural system.

3. Double-click the structural systems Setup cell. In the Mechanical application, an Imported Body Temperature load is automatically added into the structural system’s tree under an Imported Load folder. 4. Select appropriate geometry in the Details view of the Imported Body Temperature object using the Geometry or Named Selection scoping option. If the load is scoped to one or more surface bodies, the Shell Face option in the details view allows you to apply the temperatures to Both faces, to the Top face(s) only, or to the Bottom face(s) only. See Imported Body Temperature for additional information.

Note In a 3D analysis, if the Triangulation mapping algorithm is used, the Transfer Type mapping option defaults to Surface when the load is scoped to shell bodies.

5. The Source Bodies option in the Details view allows you to select the bodies, from the thermal analysis, that make up the source mesh for mapping the data. You can choose one of the following options: – Automatic- Heuristics based on the geometry are used to automatically match source and target bodies and map temperature values. A source body is matched with a target body if it satisfies the below criteria. a. The percent volume difference is within the user defined tolerance. b. The distance between the centroid locations divided by the diagonal of the bounding box is within the user defined tolerance. The percent tolerance values can be specified in the Tolerance field. The default is set at 1%. The matching process is done in increments of 0.1 of the tolerance value, up to the defined tolerance. The process fails if multiple source bodies are found to match a target body or if no match is found for a target body. After the import is completed, a Load Transfer Summary is displayed as a comment object in the particular load branch. The summary shows the matched

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Special Analysis Topics source and target bodies as well as the values that were used to determine the match. It is recommended that you verify the import using this information.

Important This option requires the element volume results to be present in the thermal results file. Make sure that the Calculate Thermal Flux or the General Miscellaneous Details view property under the Analysis Settings object in the thermal analysis is set to Yes, so that this result is available.

Note This option is not allowed when scoped to a node-based Named Selection as the heuristic is geometry based.

– All- The source mesh in this case will comprise of all the bodies that were used in thermal analysis. For cases where the temperature values are significantly different at the boundaries across two or more bodies, this option could result in mapped target values that are generated by taking a weighted average of the source values across multiple bodies. Target regions can exists where the mapped temperatures differ significantly from the source. – Manual- This option allows you to select one or more source bodies to make up the source mesh. The source body selections are made in the Material IDs field by entering the material IDs that correspond to the source bodies that you would like to use. Type material IDs and/or material ID ranges separated by commas to specify your selection. For example, type 1, 2, 5-10. The material IDs for the source bodies can be seen in Solution Information Object of the source analysis. In the example below, text is taken from a solver output, ***********Elements for Body 1 «coil» *********** ***********Elements for Body 2 «core» *********** ***********Elements for Body 3 «bar» ************

body ‘coil’ has material ID 1, body ‘core’ has material ID 2 and body ‘bar’ has material ID 3. 6. Change any of the columns in the Data View tab as needed: – Source Time — The time at which the data will be imported from the coarse analysis. – Analysis time — Choose the analysis time at which the load will be applied.

Note The Data View can automatically be populated with the source and analysis times using Source Time property in the Details view. Use All to import data at all times in the source analysis, or Range to import data for a range specified by a Minimum and a Maximum.

7. You can transform the source mesh used in the mapping process by using the Rigid Transformation properties. This option is useful if the source geometry was defined with respect to a coordinate system that is not aligned with the target geometry system.

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Analysis Types 8. You can modify the Mapper Settings to achieve the desired mapping accuracy. Mapping can be validated by using Mapping Validation objects. 9. Right-click the Imported Body Temperature object and click Import Load to import the load. When the load has been imported successfully, a contour plot of the temperatures will be displayed in the Geometry window. 10. You can define multiple rows in the Data View tab to import source data at multiple times and apply them at different analysis. If multiple rows are defined in the Data View, it is possible to preview imported load vectors/contour applied to a given row or analysis time in the Data View. Choose Active Row or Analysis Time using the By property under Graphics Controls in the details of the imported load and then specify the Active Row/Analysis Time to preview the data.

Note If the Analysis Time specified by the user does not match the list of analysis times in the Data View, the data is displayed at the analysis time closest to the specified time.

Note a. You can add a template for the linked thermal and structural systems by creating your own template. b. The transfer of temperatures is not allowed between a 2D analysis and 3D analysis or vice-versa.

Note When there is a shared model that includes a thermal-stress analysis and the structural system is duplicated using the Engineering Data, Geometry or Model cell context menu, the result is the Setup cell of the Thermal system linked to the Solution cell of the duplicated structural system. Temperature transfer to the duplicated structural system will require the data to be mapped and interpolated between the source and target meshes.

One-way Acoustic Coupling Analysis The Mechanical application allows you to apply velocities from a Structural Harmonic Response analysis as loads in an Acoustic analysis. The load transfer is applicable for the cases where the harmonic response and acoustic analyses are solved using different meshes. In this case, the velocity values are mapped and interpolated between the source and target meshes. An acoustic analysis is performed via ACT. For information on creating optimization extensions, see the Application Customization Toolkit Developer’s Guide and the Application Customization Toolkit Reference Guide. These documents are part of the ANSYS Customization Suite on the ANSYS Customer Portal. Workflow for performing a one-way acoustic coupling analysis. 1. From the toolbox, drag and drop a Harmonic Response template onto the project schematic. Perform all steps to set up a Harmonic Analysis. Specify mesh controls, boundary conditions, and solution settings as you normally would and solve the analysis.

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Special Analysis Topics 2. Drag and drop a Harmonic Response template onto the project schematic. Drag the Solution cell of the structural system onto the Setup cell of the acoustic system.

3. Double-click the acoustic system’s system Setup cell. In the Mechanical application, insert an Imported Velocity load into the acoustic system’s tree under an Imported Load folder. 4. Select appropriate geometry in the Details view of the imported velocity object using the Geometry or Named Selection scoping option. 5. The Source Bodies option in the Details view allows you to select the bodies, from the thermal analysis, that makeup the source mesh for mapping the data. You can choose one of the following options: • All- The source mesh in this case will comprise of all the bodies that were used in structural analysis. • Manual- This option allows you to select one or more source bodies to make up the source mesh. The source body selections are made in the Material IDs field by entering the material IDs that correspond to the source bodies that you would like to use. Type material IDs and/or material ID ranges separated by commas to specify your selection. For example, type 1, 2, 5–10. The material IDs for the source bodies can be seen in Solution Information Object of the source analysis. In the example below, text is taken from a solver output, ***********Elements for Body 1 «coil» *********** ***********Elements for Body 2 «core» *********** ***********Elements for Body 3 «bar» ************

body ‘coil’ has material ID 1, body ‘core’ has material ID 2 and body ‘bar’ has material ID 3. 6. Change any of the columns in the Data View tab as needed: • Source Frequency- Frequency at which the velocities will be imported from the structural analysis. • Analysis Frequency- Choose the analysis frequency at which the load will be applied.

Note The Data view can automatically be populated with the source and analysis frequencies using the Source Frequency property in the Details View. Use All to import data at all frequencies in the source analysis, or Range to import data for a range specified by a Minimum and Maximum. The default worksheet option requires users to manually input the Source Frequency and Analysis Frequency.

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Analysis Types 7. You can transform the source mesh used in the mapping process by using the Rigid Transformation properties. This option is useful if the source geometry was defined with respect to a coordinate system that is not aligned with the target geometry system. 8. You can modify the Mapper Settings to achieve the desired mapping accuracy. Mapping can be validated by using Mapping Validation objects. 9. Right-click the Imported Velocity object and click Import Load to import the load. When the load has been imported successfully, vectors plot (All), or contour plot (Total/X/Y/Z) of the real/imaginary components of velocities can be displayed in the Geometry window using the Component property in the details of imported load.

Note The range of data displayed in the graphics window can be controlled using the Legend controls options. See Imported Boundary Conditions for additional information.

10. If multiple rows are defined in the Data view, it is possible to preview imported load vectors/contour applied to a given row or analysis frequency in the Data view. Choose Active Row or Analysis Frequency using the By property under Graphics Controls in the details of the imported load and then specify the Active Row/Analysis Frequency to preview the data.

Note If the Analysis Frequency specified by the user does not match the list of analysis frequencies in the Data View, the data is displayed at the analysis frequency closest to the specified frequency.

Rotordynamics Analysis Rotordynamics is a specialized branch of applied mechanics that studies the behaviors of rotating structures. This rotating structure, or “rotor system “, is typically comprised of rotors, stators, and bearings. For a simple rotor system, the rotor component rotates about an axis that is stabilized by a bearing that is supported by a stator. This structure can be as simple as computer disk or as complicated as a jet engine. The Mechanical Rotordynamics Analysis helps to direct you when selecting properties such as rotor stiffness and geometry, bearing stiffness, damping, and stator properties for a rotor system based on a given rotating speed. For example, to effectively study a system’s vibratory characteristics, you can use a Campbell diagram. A Campbell diagram allows you to determine critical speeds (for different rotating modes), such as the rate at which the rotating structure experiences resonance (peak response) to avoid possible catastrophic failure. Or, a Rotordynamic Analysis can be used to determine safe operational ranges for a rotor system. In the Mechanical documentation, see the Rotordynamics Controls section for more information, and in the Mechanical APDL documentation, the Rotordynamic Analysis Guide. Refer to the following areas of the documentation for additional and associated information for Rotordynamics:

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Special Analysis Topics • Import Shaft Geometry • Bearings • Campbell Diagram Chart Results

Fracture Analysis Fracture analysis deals with the computation of fracture parameters that help you design within the limits of catastrophic failure of a structure. Fracture analysis assumes the presence of a crack in the structure. The fracture parameters computed are Stress Intensity Factors (SIFS), J-Integral (JINT) and Energy Release Rates. For more information about fracture parameters, modes, and calculation techniques, see Fracture Mechanics in the Structural Analysis Guide. Fracture analysis requires that you define a crack. Since fracture parameter calculation requires knowledge of the mesh characteristics around the crack, the mesh must be generated before solving for fracture parameters. Fracture parameter computation is only applicable to static structural analyses. For more information on Fracture Analysis, see the following topics: Cracks Solving a Fracture Analysis Fracture Results Limitations of Fracture Analysis Interface Delamination and Contact Debonding Additional topics include: Fracture Analysis Workflows Multi-Point Constraint (MPC) Contact for Fracture

Fracture Analysis Workflows This section describes the typical workflow for computing fracture parameters in the static structural analysis that contains cracks. The typical workflows are shown below:

Note For all workflows, the static structural analysis supports imported thermal loads from both steady-state thermal or transient thermal analysis by linking the set up cell of the static structural analysis to the upstream steady-state thermal or transient thermal analysis.

Known Crack Location The steps shown below describe setting up the fracture analysis when the location of crack is known. The crack location and its alignment are dictated by the coordinate system selected by the crack object. 1.

In ANSYS Workbench, insert a Static Structural analysis in the project schematic.

2.

Input geometry.

3.

Locate a coordinate system with a graphic pick point, coordinates, or topology. The coordinate system must be located on the surface.

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Analysis Types 4.

Align the axes of the coordinate system of the crack. The specified coordinate system’s y-axis must be pointing in the direction normal to the crack surface. For cracks lying on curved surfaces, ensure that the coordinate system’s x-axis is pointing normal to the surface of the body at the coordinate system location. See Creating a Coordinate System Based on a Surface Normal (p. 487) for details on how to orient such a coordinate system on a curved surface..

5.

Insert a Fracture folder in the Tree Outline.

6.

Insert a Crack object under the Fracture folder.

7.

Specify the crack object details.

8.

Generate the mesh by right-clicking the Fracture folder and selecting Generate All Crack Meshes.

9.

Apply loads and boundary conditions.

10. Apply any pressure on crack face if necessary. 11. Ensure the Fracture setting under Solver Controls in the Analysis Settings is turned on. 12. Solve. 13. Add the Fracture tool and Fracture Result. 14. Post process the Fracture Result. 15. Export to Excel or copy/paste from the chart if necessary.

Imported Crack Mesh This workflow describes using the Pre-Meshed crack object for the computation of fracture parameters in 2D and 3D analysis using imported crack mesh. 1.

In ANSYS Workbench, insert a Static Structural analysis in the project schematic.

2.

Input the mesh through FE Modeler. The imported mesh contains the crack mesh and its definition.

3.

Create a coordinate system with a Y axis perpendicular to the crack faces.

4.

Insert a Fracture folder in the Tree Outline.

5.

Insert a Pre-Meshed Crack object under the Fracture folder.

6.

Specify the crack object details.

7.

Associate the Pre-Meshed Crack object with the created coordinate system.

8.

Apply load and boundary conditions.

9.

Ensure the Fracture setting under Solver Controls in the Analysis Settings is turned on.

10. Solve. 11. Add the Fracture tool and Fracture Result. 12. Post process the Fracture Result.

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Special Analysis Topics 13. Export to Excel or copy/paste from the chart if necessary.

Note In 2D, you can draw the crack in the same model using DesignModeler and generate the crack mesh using the mesh connection feature. For a tutorial addressing this issue, see Fracture Analysis of a 2D Cracked Specimen using Pre-Meshed Crack (p. 1528).

Limitations of Fracture Analysis This section describes the limitations for the generation of crack mesh using Crack object. It also describes the limitations in the computation of fracture parameters using the Crack and Pre-Meshed crack objects. 1. Fracture analysis does not support adaptive mesh refinement. 2. The Crack object is only supported for 3D analysis. 3. The Crack object can only be scoped to one body. The base mesh on that body must be quadratic tetrahedron mesh. 4. The stiffness behavior of the scoped geometry selection of the Crack object must be flexible. 5. The scoped crack front nodal selection of the Pre-Meshed Crack object must exist in geometries with a flexible stiffness behavior definition. 6. Fracture parameter computations based on the VCCT technique are only supported for lower order crack mesh. Hence, VCCT based fracture parameter computations are only supported for Pre-Meshed Crack object. 7. Solution Restarts are not supported with the computation of fracture parameters. Solution Restarts can be used for solving an analysis of cracks without computing the fracture parameters by turning “Off” the “Fracture” setting under Solver Controls. 8. The Crack object only supports semi-elliptical surface cracks. 9. The crack top and bottom face nodes are not connected through any constraint equation. So the nodes of the top face can penetrate the bottom face or vice versa based on the applied loads and constraints. In these scenarios, you may need to create a constraint equation between crack faces during solution using the Commands object. 10. The graphical view of the crack may differ from the generated mesh. For more information, see the section on Cracks (p. 471). 11. Crack object is not supported for Cyclic Symmetry Region and Structural Linear Periodic Symmetry Region objects. 12. Interpolated displacements for the facets in a surface construction object may fail to demonstrate the proper deformation of a crack. For more information, see Surface Displays and Fracture (p. 1009).

Multi-Point Constraint (MPC) Contact for Fracture The internally generated crack mesh is created after an initial base mesh is generated. Since the crack mesh is defined based on the crack object, while the base mesh is created based on the geometry and mesh parameters, the two meshes may not perfectly match at the boundaries of the fracture affected Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Analysis Types zone. For more information on the fracture affected zone, see the Fracture Meshing section in the Meshing User’s Guide. When a solution is performed on an analysis which contains an internally generated crack mesh, a contact region using Multi-Point Constraint (MPC) formulation is automatically created between the crack mesh and the base mesh at the boundaries of the fracture-affected zone. This contact is applicable to static structural analysis, steady-state thermal analysis, and transient thermal analysis. For more information about the MPC contact formulation, see Contact Formulation Theory. This contact is only created for a Crack object and is not applicable to the Pre-Meshed Crack object. The characteristics/settings of the MPC contact are shown below. For more information about the different contact settings, see Advanced Settings. • Bonded surface-to-surface contact is defined between the crack mesh and the base mesh at the boundary of the fracture-affected zone. The contact element CONTA174 is created on the faces of the crack mesh, and the target element TARGE170 is created on the faces of the base mesh. • The contact is asymmetric in nature. The contact can be made auto asymmetric by setting the use auto symmetric variable to 1 in the Variable Manager. • Nodal contact detection, normal from the contact surface, will be defined. • The initial gap and penetration are ignored. • For steady-state thermal and transient thermal analysis, the temperature degree of freedom is selected. For more information about contact settings, refer to the CONTA174 documentation in the Element Reference. For more information about the MPC constraint, see Multipoint Constraints and Assemblies in the Mechanical APDL Contact Technology Guide.

Composite Analysis Composite analysis can be performed inside Mechanical by importing the layered section information defined on a Mechanical model in an ACP system. The following information discusses the workflow for shell and solid modeling. • Shell Modeling Workflow (p. 364) • Solid Modeling Workflow (p. 366)

Shell Modeling Workflow Composite shells defined using ACP can be imported into Mechanical for analysis by using an Imported Layered Section object. To import composite shells from ACP into Mechanical follow the procedure below: 1. From the toolbox, drag and drop an ACP (Pre) system onto the project schematic. Perform all the steps to fully define the ACP (Pre) system. 2. Then drag and drop a supported* Mechanical system on the ACP (Pre) system. This will share the Engineering Data, Geometry and Model cells from ACP system to the Mechanical system.

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Special Analysis Topics

Note • A Section Data cell is inserted in the Mechanical system, which represents the imported section data. • An Imported Layered Section object is inserted in the Mechanical application when a transfer connection is created from the Setup of an ACP (Pre) system to a Section Data cell.

3. Perform all the steps to fully define the Mechanical system and perform analysis. 4. Review the results. Layered results can be viewed in Mechanical, see Surface Body Results for details. To utilize additional post processing capabilities within ACP, drag an ACP (Post) system onto the ACP (Pre) Model cell, then connect the Solution cell of the supported* Mechanical system onto the ACP (Post) Results cell.

Note • Multiple Mechanical systems can be linked to perform complex workflows exactly like standard analyses. Since only one layered section(s) definition can exist per Mechanical Model, for all the systems sharing the Model cell, Section Data cell is also shared.

• The following information is transferred from ACP Setup to Section Data cell: – Sections

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Analysis Types – Elements assigned to each section – Layers definition for each section – Material assignment for each layer Since the material assignment is transferred from ACP Setup to the Mechanical system, the engineering data cells of the ACP and Mechanical system(s) must be shared. The refresh of the ACP system fails if unshared Engineering Data cells are detected.

*Supported Mechanical system(s) • Static Structural • Transient Structural • Modal • Harmonic Response • Random Vibration • Response Spectrum • Explicit Dynamics • Linear Buckling

Solid Modeling Workflow A Composite solid defined using ACP can be imported into Mechanical for analysis by importing the mesh from upstream ACP system(s) and synthesizing the geometry from the imported meshes. To import a composite solid from ACP into Mechanical, follow the procedure below: 1. From the toolbox, drag and drop ACP (Pre) system onto the project schematic. Perform all the steps to fully define the ACP (Pre) system. 2. Then drag and drop a supported* Mechanical system onto the project schematic and create a transfer link from ACP (Pre) Setup cell to the Mechanical System model. This connection enables the transfer of mesh, geometry and engineering data from ACP (Pre) Setup cell to Mechanical Model cell.

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Special Analysis Topics Figure 19: ACP — Mechanical Connection

Note • Since the geometry and engineering data is provided by the upstream ACP system, they are removed from the downstream Mechanical system. • Meshes can be imported into Mechanical from multiple ACP systems. Mechanical does not allow overlap of node/element number from multiple ACP systems; therefore, the import fails if the meshes from different ACP systems have overlap in node/element numbers.

3. Double click/edit the downstream Model cell. In the Mechanical application, an Imported Layered Section object is already inserted. 4. Perform all the steps to fully define the Mechanical system and perform analysis.

Note • Since the mesh is imported from an upstream Mechanical system, any operations that affect the mesh state are blocked inside of Mechanical. • It is recommended that you do not affect the mesh inside Mechanical; however, the Clear Generated Data option is available on the mesh folder inside Mechanical and cleans the imported mesh. The Generate Mesh/Update operation resumes the imported mesh previously cleaned/modified. • Since the material is assigned to elements/bodies through upstream ACP system, the Material Assignment field is read only and says, “Composite Material”. • If the Setup cell of the upstream ACP system(s) is modified, then the refresh of the downstream Model cell re-imports the meshes and re-synthesizes the geometry. This has the following effects: – Any properties set on the bodies imported from ACP system are reset to the defaults. – Any scoping to geometry (bodies/faces/edges/vertices) is lost and any loads/boundary conditions scoping to geometry have to be re-scoped. • Any criterion based named selections defined in the downstream Mechanical system are updated on refresh after any modification in upstream ACP system.

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Analysis Types – Since criterion based named selections are automatically updated, where as any direct scoping is lost, user should create criterion based named selections and then scope any loads/boundary conditions to these named selections. This will result in persistence of scoping during modify/refresh operations.

5. Review the results. Layered results can be viewed in Mechanical, see Surface Body Results for details. To utilize additional postprocessing capabilities within ACP, drag an ACP (Post) system onto the ACP (Pre) Model cell, then connect the Solution cell of the supported* Mechanical system onto the ACP (Post) Results cell.

Mixing of composite (layered) solids and non-layered shells/solids Non-layered shells/solids can also be imported into Mechanical along with layered solids to perform mixed analysis, where some bodies have layer information and others do not. To perform mixed analysis inside of Mechanical: 1. First drag and drop an ACP (Pre) system onto the project schematic. 2. Then drag and drop a supported* Mechanical system onto the project schematic and create a link from ACP (Pre) Setup cell to Mechanical System Model cell. 3. Then drag and drop Mechanical Model system onto the project schematic and create a transfer link from Model cell of upstream system to Model cell of downstream system.

Note • Meshes from upstream to downstream Mechanical Model are renumbered automatically to avoid any overlap with the meshes imported from ACP system(s).

4. Double-click/edit the downstream Model cell. In the Mechanical application, an Imported Layered Section is already inserted. 5. Perform all the steps to fully define the Mechanical system and perform analysis.

Note • The following information is transferred from upstream to downstream Mechanical Model:

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Special Analysis Topics – Geometry (Parts/Bodies) and material assigned to bodies. – Mesh – Named selections scoped to face(s) • Since the material assignment is transferred from upstream to downstream Mechanical system, the Material Assignment field is read only and displays the material assigned to the body. • If the model cell of the upstream Model system or the Setup cell of the ACP system is modified, then the refresh of the downstream Model cell re-imports the meshes and resynthesizes the geometry. Any properties set on the bodies imported from the Mechanical model are retained.

6. Review the results. Layered results can be viewed in Mechanical, see Surface Body Results for details. To utilize additional postprocessing capabilities within ACP, drag an ACP (Post) system onto the ACP (Pre) Model cell, then connect the Solution cell of the supported* Mechanical system onto the ACP (Post) Results cell. *Supported Mechanical system(s) • Static Structural • Transient Structural • Steady-State Thermal • Transient Thermal • Modal • Harmonic Response • Random Vibration • Response Spectrum • Linear Buckling

Note Although both Structural and Thermal layer modeling is available, the particular degrees of freedom results on correspondent layers could behave differently in structural and thermal environments, see the Mechanical APDL Element Reference for correspondent elements, including: SOLID185 Layered Structural Solid Assumptions and Restrictions and SOLID278 Layered Thermal Solid Assumptions and Restrictions.

Limitations If the Engineering Data Cell of the intended downstream Mechanical System is modified (by creating/modifying an existing material in Engineering Data cell of the Mechanical System), a Data Transfer

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Analysis Types connection from Upstream ACP (Pre) Setup/Mechanical Model to downstream Mechanical system cannot be created.

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Specifying Geometry in the Mechanical Application The following topics are included in this section: Geometry Basics Solid Bodies Surface Bodies Line Bodies Mesh-Based Geometry Assembling Mechanical Models Rigid Bodies 2D Analyses Symmetry Named Selections Mesh Numbering Path (Construction Geometry) Surface (Construction Geometry) Remote Point Point Mass Thermal Point Mass Cracks Interface Delamination and Contact Debonding Gaskets

Geometry Basics While there is no limit to the number of parts in an assembly that can be treated, large assemblies may require unusually high computer time and resources to compute a solution. Contact boundaries can be automatically formed where parts meet. The application has the ability to transfer structural loads and heat flows across the contact boundaries and to «connect» the various parts. Parts are a grouping or a collection of bodies. Parts can include multiple bodies and are referred to as multibody parts. The mesh for multibody parts created in DesignModeler will share nodes where the bodies touch one another, that is, they will have common nodes at the interfaces. This is the primary reason for using multibody parts. Parts may consist of: • One or more solid bodies. • One or more surface bodies. • One or more line bodies. • Combinations of line and surface bodies.

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Specifying Geometry All other combinations are not practically supported.

Note Body objects in the tree that represent a multibody part do not report centroids or moments of inertia in their respective Details view. The following topics are addressed in this section: Multibody Behavior Working with Parts Associativity Integration Schemes Color Coding of Parts Working with Bodies Hide or Suppress Bodies Hide or Show Faces Assumptions and Restrictions for Assemblies, Parts, and Bodies

Multibody Behavior Associativity that you apply to geometry attached from DesignModeler is maintained in the Mechanical and Meshing applications when updating the geometry despite any part groupings that you may subsequently change in DesignModeler. See Associativity (p. 372) for further information. When transferring multibody parts from DesignModeler to the Meshing application, the multibody part has the body group (part) and the prototypes (bodies) beneath it. When the part consists of just a single body the body group is hidden. If the part has ever been imported as a multibody part you will always see the body group for that component, regardless of the number of bodies present in any subsequent update.

Working with Parts There are several useful and important manipulations that can be performed with parts in an assembly. • Each part may be assigned a different material. • Parts can be hidden for easier visibility. • Parts can be suppressed, which effectively eliminates the parts from treatment. • The contact detection tolerance and the contact type between parts can be controlled. • When a model contains a Coordinate Systems object, by default, the part and the associated bodies use the Global Coordinate System to align the elements. If desired, you can apply a local coordinate system to the part or body. When a local coordinate system is assigned to a Part, by default, the bodies also assume this coordinate system but you may modify the system on the bodies individually as desired.

Associativity Associativity that you apply to geometry originating from DesignModeler is maintained in the Mechanical and Meshing applications when the geometry is updated despite any part groupings that you may

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Geometry Basics subsequently change in DesignModeler. Types of associativity that you can apply include contact regions, mesh connections, loads, and supports. For example, consider the following scenario: 1. A model is created in DesignModeler and is comprised of six independent parts with one body per part. 2. The model is attached to Mechanical where loads and supports are applied to selected geometry. 3. In DesignModeler, the model is re-grouped into two multibody parts with each part including three bodies. 4. The geometry is updated in Mechanical. The loads and supports remain applied to the same selected geometry.

Note This feature does not hold true for instanced parts in DesignModeler. The associativity is maintained only with geometry attached from DesignModeler and Mechanical systems created in release 13.0 or later. To ensure that the data necessary for retaining associativity is present in legacy dsdb/wbpj databases, you should perform the following: 1. Open the Mechanical session and open the DesignModeler session. This will ensure that both the Mechanical and DesignModeler files are migrated to the current version of the software. 2. Update the geometry model without making any changes to the model. This will ensure that the new data necessary for associativity is transferred from the migrated DesignModeler file into the migrated Mechanical file. 3. You can now modify and update the geometry as necessary.

Maintaining Associativity with Geometry Updates in FE Modeler When updating a model from FE Modeler in Mechanical, all geometry scoping on objects (such as loads, results, etc.) is lost. For this reason, it is recommended that you either use imported named selections or criteria-based named selections for scoping of objects, since these are automatically updated when the model update is complete.

Integration Schemes Parts can be assigned Full or Reduced integration schemes. The full method is used mainly for purely linear analyses, or when the model has only one layer of elements in each direction. This method does not cause hourglass mode, but can cause volumetric locking in nearly incompressible cases. The reduced method helps to prevent volumetric mesh locking in nearly incompressible cases. However, hourglass mode might propagate in the model if there are not at least two layers of elements in each direction.

Color Coding of Parts You can visually identify parts based on a property of that part. For example, if an assembly is made of parts of different materials, you can color the parts based on the material; that is, all structural steel parts have the same color, all aluminum parts have the same color and so on. Select a color via the Display Style field of the Details view when the Geometry branch in the feature Tree is selected. You can specify colors based on: Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Specifying Geometry • Body Color (default): Assigns different colors to the bodies within a part. • Part Color: Assigns different colors to different parts. • Material: The part colors are based on the material assignment. For example in a model with five parts where three parts use structural steel and two parts use aluminum, you will see the three structural steel parts in one color and the two aluminum parts in another color. The legend will indicate the color used along with the name of the material. • Nonlinear Material Effects: Indicates if a part includes nonlinear material effects during analysis. If you chose to exclude nonlinear material effects for some parts of a model, then the legend will indicate Linear for these parts and the parts will be colored accordingly. • Stiffness Behavior: Identifies a part as Flexible, Rigid, or Gasket during analysis.

Note A maximum of 15 distinct materials can be shown in the legend. If a model has more then 15 materials, coloring by material will not have any effect unless enough parts are hidden or suppressed. You can reset the colors back to the default color scheme by right clicking on the Geometry object in the tree and selecting Reset Body Colors. Example 2: Color by Parts

Working with Bodies There are several useful and important manipulations that can be performed with bodies in a part. • Bodies grouped into a part result in connected geometry and shared nodes in a mesh. • Each body may be assigned a different material. • Bodies can be hidden for easier visibility.

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Geometry Basics • Bodies in a part group can be individually suppressed, which effectively eliminates these bodies from treatment. A suppressed body is not included in the statistics of the owning part or in the overall statistics of the model. • Bodies can be assigned Full or Reduced integration schemes, as described above for parts. • When bodies in part groups touch they will share nodes where they touch. This will connect the bodies. If a body in a part group does not touch another body in that part group, it will not share any nodes. It will be free standing. Automatic contact detection is not performed between bodies in a part group. Automatic contact detection is performed only between part groups. • Bodies that are not in a part group can be declared as rigid bodies. • When a model contains a Coordinate Systems object, by default, bodies use the Global Coordinate System. If desired, you can apply a local coordinate system.

Hide or Suppress Bodies For a quick way to hide bodies (that is, turn body viewing off ) or suppress bodies (that is, turn body viewing off and remove the bodies from further treatment in the analysis), select the bodies in the tree or in the Geometry window (choose the Body select mode, either from the toolbar or by a right-click in the Geometry window). Then right-click and choose Hide Body or Suppress Body from the context menu. Choose Show Body, Show All Bodies, Unsuppress Body, or Unsuppress All Bodies to reverse the states. The following options are also available: • Hide All Other Bodies, allows you to show only selected bodies. • Suppress All Other Bodies, allows you to unsuppress only selected bodies.

Note • If another model level object, such as a Remote Point, Joint, or Contact Region, is scoped to a Body that becomes Suppressed, that object also becomes suppressed until it is re-scoped or the body is Unsuppressed. • Results from hidden bodies are used in the formulation of the maximum and minimum values in the contour legend and in the Details View. • Results from suppressed bodies are suppressed and are not used in the formulation of maximum and minimum values.

Hide or Show Faces You can hide selected faces on a model such that you are able to see inside the model. This feature is especially useful for bodies with interior cavities, such as engine blocks. To use the feature, first select faces on the model that you want to hide, then right-click anywhere in the Geometry window and choose Hide Face(s) in the context menu. This menu choice is only available if you have already selected faces.

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Specifying Geometry Choose Show Hidden Face(s) from the context menu to restore the visibility of faces previously hidden using Hide Face(s). The Show Hidden Face(s) menu choice is only available if there are hidden faces from choosing Hide Face(s). It cannot be used to restore the visibility of faces previously hidden by setting Visible to No in the Details view of a Named Selection object.

Note The selected faces will appear hidden only when you view the geometry. The feature is not applicable to mesh displays or result displays.

Assumptions and Restrictions for Assemblies, Parts, and Bodies Thermal and shape analysis is not supported for surface bodies or line bodies. In order for multiple bodies inside a part to be properly connected by sharing a node in their mesh the bodies must share a face or edge. If they do not share a face or an edge the bodies will not be connected for the analysis which could lead to rigid body motion. Automatic contact detection will detect contact between bodies within a multibody part.

Solid Bodies You can process and solve solid models, including individual parts and assemblies. An arbitrary level of complexity is supported, given sufficient computer time and resources.

Surface Bodies You can import surface bodies from an array of sources (see Geometry Preferences). Surface bodies are often generated by applying mid-surface extraction to a pre-existing solid. The operation abstracts away the thickness from the solid and converts it into a separate modeling input of the generated surface. Surface body models may be arranged into parts. Within a part there may be one or more surface bodies; these may even share the part with line bodies. Parts that feature surface bodies may be connected with the help of spot welds and contacts. The following topics are addressed in this section. Assemblies of Surface Bodies Thickness Mode Importing Surface Body Models Importing Surface Body Thickness Surface Body Shell Offsets Specifying Surface Body Thickness Specifying Surface Body Layered Sections Faces With Multiple Thicknesses and Layers Specified

Assemblies of Surface Bodies While preparing an assembly of surface bodies for solution you may find the need to understand and modify the connectivity of the bodies involved. Mechanical offers tools to help you accomplish these tasks. For example, you may:

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Surface Bodies • Confirm whether two surface bodies are topologically connected. This may be especially useful for surface bodies obtained from a mid-surface operation on solids and created artificial gaps in their proximity. • Confirm the connectivity of individual elements in the mesh of the surface bodies. • Mend missing connections between surface bodies by joining their meshes with shared nodes. To confirm the connectivity of surface bodies it is useful to review the connectivity of their edges using a number of features in both Mechanical and DesignModeler. Edges can be classified depending on the number of faces they topologically connect. For example, the boundary edge of a surface body connects to a single face and is classified as a «single edge”, whereas an interior edge connecting two faces of the surface body will be classified as a «double edge». Single and double edges can be distinguished visually using the Edge Graphics Options (p. 71). As an alternative, you can create a Named Selection that groups all edges of a given topological connectivity by using the Face Connections criterion. The Edge Graphics Options toolbar can also be used to review the connectivity of not only the geometry, but also the mesh elements. The same principles applied to the connectivity of a surface body edge apply to element edges. Mechanical provides Mesh Connections to mend surface body assemblies at locations that are disjointed. With this feature, the meshes of surface bodies that may reside in different parts can be connected by joining their underlying elements via shared nodes. The Mesh Connection does not alter the geometry although the effect can be conveniently previewed and toggled using the Edge Graphics Options toolbar.

Thickness Mode You can determine the source that controls the thickness of a surface body using the Thickness Mode indication combined with the Thickness field, both located in the Details view of a surface Body object. Upon attaching a surface body, the Thickness Mode reads either Auto or Manual. • In Auto Mode the value of thickness for a given surface body is controlled by the CAD source. Future CAD updates will synchronize its thickness value with the value in the CAD system. • In Manual mode the thickness for the surface body is controlled by the Mechanical application, so future updates from the CAD system will leave this value undisturbed. • A Thickness Mode will be Automatic until the Thickness is changed to some non-zero value. Once in Manual mode, it can be made Automatic once again by changing the Thickness value back to zero. A subsequent CAD update will conveniently synchronize the thickness with the value in the CAD system. Thicknesses for all surface bodies are represented in a dedicated column on the Worksheet that is displayed when you highlight the Geometry object.

Importing Surface Body Models To import a surface body model (called a sheet body in NX), open the model in the CAD system and import the geometry as usual. If your model mixes solid bodies and surface bodies, you should select which type of entity you want to import via the Geometry preferences in the Workbench Properties

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Specifying Geometry of the Geometry cell in the Project Schematic. Once in the Mechanical application, you can adjust the Geometry preferences in the Details view, where they take effect upon updating.

Note If you want to retain a preference selection in the Workbench Properties, you must first save before exiting the ANSYS Workbench.

Importing Surface Body Thickness When thickness is defined on the entire surface body Surface body thickness will be imported from CAD (including DesignModeler) if, and only if, the existing surface body thickness value in the Mechanical application is set to 0 (zero). This is true on initial attach and if you set the surface body thickness value to zero prior to an update. This allows you the flexibility of updating surface body thickness values from CAD or not.

Surface Body Shell Offsets Surface bodies have a normal direction, identified by a green coloring when the surface body face is selected. Shell elements have a “top” surface (farthest in the positive normal direction) and a “bottom” (farthest in the negative normal direction).

By default, the shell section midsurface is aligned with the surface body, but you can use the Offset Type drop down menu located in the Details view of a Surface Body object or an object scoped to a surface body to offset the shell section midsurface from the surface body: • Top — the top of the shell section is aligned with the surface body.

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Surface Bodies

• Middle (Membrane) (default) — the middle of the shell section is aligned with the surface body.

• Bottom — the bottom of the shell section is aligned with the surface body.

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• User Defined — the user defines the amount of offset (Membrane Offset), measured in the positive normal direction from the middle of the shell section to the surface body (may be positive or negative value).

Specifying Surface Body Thickness The thickness of surface bodies can be prescribed in several ways: 1. A uniform thickness over the entire body which can be defined inside Mechanical or imported from a CAD system. Thicknesses imported from CAD can be overridden by the Thickness Mode 2. A constant or spatially varying thickness applied to a selection of surfaces or bodies. 3. Thickness values imported from an upstream system. 4. Layer information can be specified using a Layered Section, or imported through an Imported Layered Section. See Faces With Multiple Thicknesses and Layers Specified (p. 386) for information on how Mechanical resolves conflicts when multiple thickness specifications are applied to the same geometry. 380

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Surface Bodies To specify the thickness of an entire surface body: Highlight the Surface Body object and, in the Details view, enter a value in the Thickness field. A value greater than 0 must be present in this field. To specify the thickness of selected faces on a surface body: 1. Highlight the Geometry folder in the tree and insert a Thickness object from the Geometry toolbar or choose Insert> Thickness (right-click and choose from context menu).

Note The Thickness object overwrites any element that is scoped to the selected surfaces that has thickness greater than 0 defined in the Details view of the Surface Body object (See above).

2. Apply scoping to selected faces on surface bodies. 3. Set the desired shell offset. 4. Define the thickness as a constant (default), with a table, or with a function: a. To define the thickness as a constant, enter the value in the Thickness field in the Details view. b. To define the thickness with a table: i.

Click the Thickness field in the Details view, then click Tabular from the flyout menu.

ii. Set the Independent Variable in the Details view to X, Y, or Z. iii. Choose a Coordinate System. The Global Coordinate System (Cartesian) is the default. iv. Enter data in the Tabular Data window. The Graph window displays the variation of the thickness. c. To define the thickness with a function: i.

Click the Thickness field in the Details view, then click Function from the flyout menu.

ii. Enter the function in the Thickness field. (Example: 45+10*x/591) iii. Adjust properties in the Graph Controls category as needed: • Number of Segments — The function is graphed with a default value of 200 line segments. You can change this value to better visualize the function. • Range Minimum — The minimum range of the graph. • Range Maximum — The maximum range of the graph.

Note • Surface body thicknesses must be greater than zero. Failures will be detected by the solver.

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Specifying Geometry • When importing surfaces bodies from DesignModeler, the associated thickness is automatically included with the import. See Importing Surface Body Thickness (p. 378) for details. • Face based thickness specification is not used for the following items. Instead the body based thickness will be used: – Assembly properties: volume, mass, centroid, and moments of inertia. This is for display in the Details view only. The correct properties based on any variable thickness are correctly calculated in the solver and can be verified through miscellaneous record results for Mechanical APDL based solutions.

Note Assembly properties are displayed as N/A (Not Applicable) if Thickness objects (Thickness, Layered Thickness, Imported Layered Thickness) are present under the Geometry object. Also, that if any Parameters are present they are set to zero. This applies to parameter value you Workbench as well — they will have values of zero.

– Meshing: auto-detection based on surface body thickness, automatic pinch controls, surface body thickness used as mesh merging tolerance. – Solution: Heuristics used in beam properties for spot welds. • Face based thickness is not supported for rigid bodies. • Variable thickness is displayed only for mesh and result displays. Location probes, Path scoped results and Surface scoped results do not display nor account for variable thickness. They assume constant thickness. • If multiple Thickness objects are applied to the same face, only those properties related to the last defined object will be sent to the solver, regardless of whether the object was defined in DesignModeler or in Mechanical. See Faces With Multiple Thicknesses and Layers Specified (p. 386) for details.

You can import thicknesses from an upstream system. Basic setup steps are given below. You can find more information on mapping data in the Mechanical application in the appendix (Appendix C (p. 1595)).

Note Thickness import is supported for 3D shell bodies or planar 2D bodies using Plane Stress. The MAPDL Solver for 3D shell bodies will use the nodal thicknesses directly via the SECFUNCTION command. For the Explicit Solver or MAPDL solver for 2D bodies, the element’s nodal thicknesses are converted to an average element thickness. To import thicknesses from an upstream system: 1. In the project schematic, create a link between the Solution cell of a system and the Model cell of an upstream system.

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Surface Bodies 2. Attach geometry to the analysis system, and then double-click Model to open the Mechanical window. An Imported Thickness folder is added under the Geometry folder and an imported thickness is added to the Imported Thickness folder, by default. 3. Select the appropriate options in the Details view. 4. Select Imported Thickness and select Import Thickness from the context menu.

Specifying Surface Body Layered Sections Layers applied to a surface body can be prescribed in several ways: • A defined Layered Section object can be scoped to a selection of surfaces on the geometry. • An Imported Layered Section can provide layer information for the elements within a surface body.

Note Layered Section objects can only be used in the following analysis types: • Explicit Dynamics • Harmonic Response • Linear Buckling • Modal • Random Vibration • Response Spectrum • Static Structural • Transient Structural

The following sections describe the use of the Layered Section object. Defining and Applying a Layered Section Viewing Individual Layers Layered Section Properties Notes on Layered Section Behavior

Defining and Applying a Layered Section 1. Highlight the Geometry object in the tree and insert a Layered Section object from the Geometry toolbar or choose Insert > Layered Section (right-click and choose from context menu). 2. Select the Scoping Method that you will use: • Geometry Selection — Click in the Geometry field that appears, to enable you to pick surface bodies or individual faces from the model and select Apply. • Named Selection — Click on the Named Selection drop down that appears and select one of the available named selections. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Specifying Geometry 3. Choose a Coordinate System. You may choose any user-defined Cartesian or Cylindrical coordinate system. The Body Coordinate System option specifies that the coordinate system selected for each body will be used. There is no default. 4. Set the desired Offset Type. Offset Type is not supported in Explicit Dynamics analyses. 5. Click on the arrow to the right of Worksheet in the Layers field then select Worksheet to enter the layer information for this Layered Section. The Layered Section worksheet can also be activated by the Worksheet toolbar button. The worksheet displays a header row, and two inactive rows labeled +Z and -Z to indicate the order in which the materials are layered. Layer one will always be the layer at the bottom of the stack (closest to -Z). When you insert a layer, all of the layers above it will renumber. To add the first layer, right click anywhere in the Layered Section Worksheet and select Add Layer. Once the layer is added: • Click in the Material column of the row and select the material for that layer from the drop-down list. • Click in the Thickness column and define the thickness of that layer. Individual layers may have zero thickness, but the total layered-section thickness must be nonzero. • Click in the Angle column and define the angle of the material properties. The angle is measured in the element X-Y plane with respect to the element X axis. This value can be entered as degrees or radians, depending on how units are specified. To add another layer, do one of the following: • With no layers selected, you can right click the header row, +Z row, or -Z row to display a context menu. Select Add Layer to Top to add a layer row at the top (+Z) of the worksheet. Select Add Layer to Bottom to add a layer row to the bottom of the worksheet (-Z). • With one or more layers selected, you can right click any selected layer to display a context menu. Select Insert Layer Above (which inserts a layer row above the selected row in the +Z direction) or Insert Layer Below (which inserts a layer row below the selected row in the -Z direction). To delete a layer, select one or more rows, right click on any selected row, and select Delete Layer. 6. Select the Nonlinear Effects and Thermal Strain Effects settings in the Material category of the Details view. The reference temperature specified for the body on which a layered section is defined is used as the reference temperature for the layers. Nonlinear Effects and Thermal Strain Effects are not supported in Explicit Dynamics analyses.

Viewing Individual Layers In the Graphics Properties section of the Details panel, the Layer To Display field allows the visualization of the thickness/offset/layer sequence of the layers composing a Layered Section object. To view a particular layer, click on the field and enter the layer number. You can use the up and down buttons or enter a layer number directly. If you enter a number larger than the maximum number of layers in that layered section, the value will be set to the maximum number of layers in that layered section. If layer zero is selected, all the layers will be drawn (without the delineation between layers) as a compact entity, shown the same as when the Mesh node is selected in the tree. All other geometry not scoped to the current Layered Section object is shown with thickness zero.

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Surface Bodies Individual layers will be visible only when Show Mesh is enabled (if the model has been meshed previously), and only on Layered Section objects. If Show Mesh is not enabled, just the geometry and the scoping will be shown on the model. When a layer is selected to display, the layer with its defined thickness, offset, and sequence will be displayed in the graphics window. Due to the limitations described for the Show Mesh option, it is recommended that the user switch back and forth if needed to Wireframe/Shaded Exterior View mode to properly see annotations.

Note When viewing Imported Layered Sections, the thickness that you see is not relative to the geometry like it is with a Layered Section object.

Layered Section Properties The following Properties are displayed in Details panel for Layered Sections: • Total Thickness — Total thickness of the section, including all of the layers defined for the section. Used when displaying the mesh. • Total Mass — Total mass of all of the layers in the section. The density of the material for each layer is calculated at a reference temperature of 22° C.

Notes on Layered Section Behavior Note • If multiple thickness objects (including Layered Section objects) are applied to the same face, only those properties related to the last defined object will be sent to the solver, regardless of whether the object was defined in DesignModeler or in Mechanical. See Faces With Multiple Thicknesses and Layers Specified (p. 386) for details. • If adjacent elements within the same part have different thickness values, the elements will appear to be ramped. • Layered Sections cannot be scoped to rigid bodies. • Layered Sections do not affect the following items: – Assembly properties: volume, mass, centroid, and moments of inertia. This is for display in the Details view only. The correct properties based on any variable thickness are correctly calculated in the solver and can be verified through miscellaneous record results for Mechanical APDL based solutions. – Meshing: auto-detection based on surface body thickness, automatic pinch controls, surface body thickness used as mesh merging tolerance. – Solution: Heuristics used in beam properties for spot welds. • A Thermal Condition applied to a Layered Section is only valid if applied to both shell faces (Shell Face is set to Both, not to Top or Bottom).

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Specifying Geometry • Layered Sections are not valid with cyclic symmetry. • The following material properties are supported by Layered Sections in an Explicit Dynamics analysis: – Isotropic Elasticity, Orthotropic Elasticity – Johnson Cook Strength, Zerilli Armstrong Strength, Steinberg Guinan Strength, Cowper Symonds Strength – Orthotropic Stress Limits, Orthotropic Strain Limits, Tsai-Wu Constants – Plastic Strain, Principal Stress, Stochastic Failure, • For orthotropic materials in Explicit Dynamics, the Z material direction is always defined in the shell normal direction. The X material direction in the plane of each element is determined by the x-axis of the coordinate system associated with the Layered Section. If the x-axis of this coordinate system does not lie in the element plane, then the x-axis is projected onto the shell in the coordinate system z-axis direction. If the z-axis is normal to the element plane, then the projection is done in the coordinate system y-axis. For cylindrical systems, it is the y-axis that is projected onto the element plane to find the Y material direction.

Faces With Multiple Thicknesses and Layers Specified Thickness and Layered Section objects may be scoped to more than one face of a surface body. As a result, a face may have more than one thickness definition. The order of precedence used to determine the thickness that will be used in the analysis is as follows: 1. Imported Layered Section objects 2. Imported Thickness objects 3. Layered Section objects 4. Thickness objects 5. Thickness as a property of a body/part For multiple objects of the same type, the object lower in the tree (more recently created) will be used in the analysis. This thickness may not be the desired thickness to be used in the analysis. In a large model, you may want to fix this problem prior to solving the model. You can search for faces with multiple thicknesses by selecting Search Faces with Multiple Thicknesses from the context menu of any of the following: the Geometry folder, a Body object (individual or group of objects), a Thickness object or a Layered Section object. For each face found with multiple thicknesses, a warning message similar to the one shown below will be displayed in the message box. This face has more than one thickness defined. You may graphically select the face via RMB on this warning in the Messages window.

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Line Bodies To find the face and its corresponding thickness objects for a particular message, highlight that message in the message pane, right-click on the message and choose Go To Face With Multiple Thicknesses from the context menu. The face associated with this message is highlighted in the Geometry window and the corresponding thickness objects are highlighted in the tree. If there is no face with multiple definitions, the following information will be displayed in the message box. No faces with multiple thicknesses have been found. A related Go To option is also available. If you highlight one or more faces with thickness definition of a surface body, then right-click in the Geometry window and choose Go To> Thicknesses for Selected Faces, the corresponding thickness objects will be highlighted in the tree.

Note You cannot search for Imported Layered Sections that overlap with other thickness objects. However a warning will be generated during the solution if this situation might exist.

Line Bodies A line body consists entirely of edges and does not have a surface area or volume. Although multiple CAD sources can provide line bodies to ANSYS Workbench, only DesignModeler and ANSYS SpaceClaim Direct Modeler provide the additional cross section data needed to use line bodies in an analysis. For those CAD sources that cannot provide the cross section data, you need to import them into DesignModeler or ANSYS SpaceClaim Direct Modeler, define the cross sections, and then send the geometry to the Mechanical application in ANSYS Workbench. Once imported, a line body is represented by a Line Body object in the tree, where the Details view includes the associated cross section information of the line body that was defined in DesignModeler or supported CAD system. Depending on your application, you can further define the line body as either a beam or a pipe. Here are some guidelines: • Beam is usually a suitable option when analyzing thin to moderately thick beam structures. A variety of cross-sections can be associated with beams. • Pipes are more suitable for analyzing initially circular cross-sections and thin to moderately thick pipe walls. Users can apply special loads on pipes such as Pipe Pressure and Pipe Temperature. Curved pipe zones or high deformation zones in pipes can be further modeled using the Pipe Idealization object. To define your line body, highlight the Line Body object and set the following in the Details view: 1. Offset Mode: to Refresh on Update (default) to enable the values in the Details view to update when the CAD system updates, or to Manual, to enable the Details view values to override the CAD system updates. 2. Model Type: to Beam or Pipe. 3. Offset Type: to Centroid, Shear Center, Origin, or User Defined, where Offset X and Offset Y are available. The following read-only information is used in the definition of both beam and pipe: • Cross Section Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Specifying Geometry • Cross Section Area • Cross Section IYY • Cross Section IZZ

Note • Beams can also be used as connections within a model. See Beam Connections (p. 614) for further information on this application. • Pipes are only realized in structural analyses. All line bodies defined in other analysis types are always realized as beams. This extends to linked analyses as well. For example, in a thermalstructural linked analysis where line bodies are defined as pipes, the thermal component of the analysis will only realize the line bodies as beams.

Viewing Line Body Cross Sections By default, line bodies are displayed simply as lines in the Geometry window, with no graphical indication of cross sections. If cross sections are defined in line bodies and you choose View> Cross Section Solids (Geometry), you enable a feature where line bodies are displayed as solids (3D), allowing you to visually inspect the cross sections. This visualization can be useful in determining the correct orientation of the line bodies. For circular and circular tube cross sections, the number of divisions used for rendering the line bodies as solids has an adjustable range from 6 to 360 with a default of 16. You can make this adjustment by choosing Tools> Options, and under Graphics, entering the number in the Number of Circular Cross Section Divisions field. The Cross Section Solids (Geometry) feature has the following characteristics: • By default, this feature is disabled. However, the setting persists as a session preference. • Only geometry displays are applicable. The feature is not available for mesh displays. • When the feature is enabled, both normal lines and solid representations are drawn. • The solid representation of the geometry cannot be selected nor meshed, and has no effect on quantitative results. • The feature supports section planes and works with all line body cross sections (primitive and user defined). • User integrated sections (direct entry of properties) will have no display. • The feature is not available for use with viewports.

Mesh-Based Geometry For solid and shell finite element mesh files generated in the Mechanical APDL common database (.cdb) format, you can import these files directly into Mechanical using the Workbench External Model system. This feature automatically synthesizes geometry from the specified mesh for use in Mechanical. The resulting geometry is the culmination of the use of the implicit (based angle tolerance) and explicit (based on node-based components in the .cdb file) methods that work in combination to synthesize geometry and create surfaces that enclose the mesh volume.

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Mesh-Based Geometry This feature supports all Mechanical analysis types. For the specific instructions to import a finite element mesh file using this tool, see the Creating and Configuring an External Model System section of the Workbench Help.

External Model Properties in Workbench The External Model component allows you to modify certain properties prior to import; including: unit systems, the number copies of the source mesh to transform, and Rigid Transformation coordinates based on source locations.

Model Properties in Workbench There are CDB Import Options available in the properties for the Model cell in the Workbench Project page. Properly defining these properties is important for you to accurately generate the desired geometries in Mechanical. As shown, CDB Import Options include: • Tolerance Angle: this value determines if adjacent elements are of the same face during the geometry creation process. The geometry creation process identifies groups of element facets on the exterior of the mesh. These generated facets create geometric faces in Mechanical. Then skin detection algorithm scans the exterior element facets and groups them based on a tolerance angle. For example, two adjacent element facets are grouped into the same face if the angle between their normals is less than or equal to the given tolerance angle. Therefore, an angle tolerance of 180o creates only a single face for the whole body while a tolerance of 1o creates an amount of geometric faces which approaches the number of element faces if any curvature is present. Calculations to synthesize geometries using tolerance angles use the implicit method. Processing nodal components on the same topology will override this method. See the illustrations below for examples of this behavior. The default Tolerance Angle is 45 degrees. This is the recommended setting. • Process Nodal Components: this option overrides Tolerance Angle during the geometry creation process if the .cdb file contains node-based components. And like Tolerance Angle, when node-based components span large portions of a model, clarity inaccuracies display in the graphical display of Mechanical. • Nodal Component Key: if the .cdb files includes nodal components, you can specify them using this property to further facilitate accurate geometries in Mechanical. Calculations to synthesize geometries using nodal components use the explicit method. This method overrides Tolerance Angle values if present. • Analysis Type: defines the .cdb file as 3D (default) or 2D. When working with 2D analysis types, make sure that all of your model’s surface normals point in the same direction using the Rigid Transformation properties available through the External Model feature.

Geometry Specifications This feature supports data import of shells or of solids or a mix of shells and solids. See the next section, CDB Import Element Types, for a list of the available element type. For shell bodies that have a constant thickness, Mechanical applies this thickness as a Geometry property. For shell bodies that do not have a constant thickness, Mechanical does not include a thickness

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Specifying Geometry value in the Geometry of the body and the body becomes underdefined; requiring you to enter a Thickness value. In addition, shell offsets are not imported. As a result, shells attach with the Offset Type property set to Middle.

Behaviors and Characteristics Note the following behaviors and characteristics for importing mesh-based geometries: • Geometry construction is for 3D solids and shells and 2D planar bodies only. Mechanical ignores any other element types contained in the .cdb file. • Mechanical only processes node-based components when attempting to create Named Selections for the faces. The application ignores element components. • You cannot change the meshes. That is, you cannot change, clear, or re-mesh once the file has been imported into Mechanical. • Mesh controls (Mesh Numbering, Refinement, etc.) are not supported. • Adaptive Mesh Refinement is not supported. • Geometry is not associative. As a result, if you update the environment, for example, by adding another .cdb file, any scoping that you have performed on an object will be lost. To avoid losses to your analysis environment, make sure that you have properly defined the imported Named Selections or criterion-based Named Selections. • The Stiffness Behavior of bodies can be set to Flexible only. • The Scale Factor Value property on the Geometry object is not supported. Examples of a geometry that results from a synthesis for a given mesh with different Tolerance Angle settings and Nodal Component Key specifications are illustrated below. Meshed Model This illustration is a graphical representation from Mechanical of the node data provided by a .cdb file. Two nodal components have been processed: CylinderNodes and SideNodes.

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Mesh-Based Geometry

45o Tolerance Angle and All Nodal Components Specified This illustration represents a synthesized geometry that includes nodal components and faces created using tolerance angles. The nodal components have overridden the tolerance angles for the SideNodes and created one large face around the geometry and the tolerance angle of 45o has caused the top faces to become merged.

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Specifying Geometry

45o Tolerance Angle and No Nodal Components Specified This illustration shows that when nodal components are not processed, the tolerance angle creates faces correctly around the side of the geometry. However, the tolerance angle of 45o once again has caused the top faces to become merged.

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Mesh-Based Geometry

25o Tolerance Angle and No Nodal Components Specified Here again nodal components are not processed but the tolerance angle has been reduced. This has resulted in a total of 27 faces being created. Note that although the chamfer faces on the top are correctly recovered, the cylinder is now made up of multiple faces.

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Specifying Geometry

25o Tolerance Angle and Cylinder Nodal Component Specified In this illustration, the CylinderNodes Nodal Component Key was specified in the properties and the Tolerance Angle was again fine-tuned to 25o. This has resulted in an accurate synthesis of the geometry.

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Mesh-Based Geometry

180o Tolerance Angle and All Nodal Components Specified This example illustrates the geometry that is synthesized using only nodal components. The tolerance angle is essentially negligible.

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Specifying Geometry

180o Tolerance Angle and No Nodal Components Specified This example illustrates how only one face is generated for the geometry when no tolerance angle (180o) is specified and no nodal components are processed. This type of result can also occur when a nodal component contains all of the nodes for a given body.

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Mesh-Based Geometry

CDB Import Element Types The following element types are supported when .cdb files are processed via the External Model system. Shape Category

Supported Mechanical APDL Element Type

2-D Linear Quadrilateral

PLANE131, PLANE251, FLUID291, PLANE551, PLANE751, INFIN1101, PLANE1621, PLANE1821, INTER192, INTER202, CPT2121

3-D Linear Quadrilateral

SHELL28, SHELL411, SHELL1311, SHELL1571, SHELL1631, SHELL1811

2-D Quadratic Triangle

PLANE35

2-D Quadratic Quadrilateral

PLANE531, PLANE771, PLANE781, PLANE831, INFIN1101, PLANE1211, PLANE1831, INTER193, INTER203, CPT2131, PLANE2231, PLANE2301, PLANE2331

3-D Quadratic Quadrilateral

SHELL1321, SHELL1571, SHELL2811

Quadratic Tetrahedral

SOLID87, SOLID98, SOLID123, SOLID168, SOLID187, CPT217, SOLID227, SOLID232, SOLID237, SOLID285

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Specifying Geometry Shape Category

Supported Mechanical APDL Element Type

Linear Hexahedral

SOLID51, FLUID301, SOLID651, SOLID701, SOLID961, SOLID971, INFIN1111, SOLID1641,SOLID1851, SOLSH1901, INTER195, CPT2151

Quadratic Hexahedral

SOLID901, INFIN1111, SOLID1221, SOLID1861, INTER194, INTER204, CPT2161, SOLID2261, SOLID2311, SOLID2361

Meshing Facet

MESH200

[1] This element supports multiple shapes. This list displays the elements in their most basic and fundamental form

Assembling Mechanical Models You can assemble multiple meshed models from the Workbench Project tab using the Mechanical Model component system, analysis type systems, and/or the External Model component system. That is, you can create multiple meshed model systems that link to one analysis environment that includes all of the individual model files. Examples of this feature are illustrated below. Model cells are linked (Model-to-Model linking). You must first mesh all of the upstream systems in order to open the models in Mechanical. Assembling Mechanical Model Systems

Assembling Mechanical Model Systems and Analysis Systems

Assembling Mechanical Model Systems and External Model Systems

Linked Model Common Properties Similar to importing mesh-based .cdb files using the External Model component system or defining Mesh-to-Mesh Connections, Model-to-Model linking provides certain Project Schematic properties for

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Assembling Mechanical Models the downstream Model cell prior to import; including: geometry length units, the number of copies of the source mesh to transform, and Rigid Transformation properties based on source locations.

Mechanical Model Systems and Analysis Systems Upstream Mechanical Model systems and analysis systems define the engineering data, geometry, and meshes for the assembled or downstream Mechanical Model system or the analysis system. The downstream analysis system can modify any existing specifications to the models once opened in Mechanical. For example, any suppressed bodies coming in from upstream systems can be unsuppressed and remeshed in the downstream environment. Once the models are imported into Mechanical, all application features are available. Limitations and Restrictions for Model Assembly Please note the following requirements for Model Systems: • Parts are made up of one or more bodies. As a result, when working with model systems, the application treats meshed parts and meshed bodies differently with regards to whether the mesh is transferred to the downstream system. Bodies meshed in an upstream system always transfer the mesh to the downstream system. However, parts (single-body or multi-body) meshed and suppressed later in an upstream system; do not have their mesh transferred to the downstream system. Consequently, when the downstream system supports unsuppression, any unsuppressed parts require you to generate a new mesh (unlike an unsuppressed body). • Geometry is not associative. As a result, if you refresh upstream model data into the downstream system, any scoping that you have performed on an object in the downstream analysis will be lost. To avoid losses to your analysis environment, make sure that you have properly defined any imported Named Selections or criterion-based Named Selections. • The Geometry object property Scale Factor Value, allows you to modify the size of imported geometries in the upstream systems. The scale factor value of newly imported geometries is 1.0. You can modify the value and that modified value is expected to be preserved on updated models.

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Specifying Geometry Be aware that when you assemble models and change the associated unit of measure, you are limited by a scale factor limit of 1e-3 to 1e3. This scale factor limit is the limit for any combination of models. Factor values are totaled and anything outside of this range is ignored. As a result, due to these tolerances, scaled models, especially larger and/or combined models, sometimes have problems importing geometry/mesh. • You need to perform material assignment in the upstream systems. The Material category property, Assignment, in the downstream system is read-only. • Model systems do not support the following features. If present, updates to the project fail for the system transferring data to a downstream system. You need to suppress or delete these features before transferring data. – Line Bodies (need to be deleted from geometry) – Rigid Bodies – Gaskets – Crack Objects – Interface layers Imported from ACP – Cyclic Symmetry – Mesh Connections – Virtual Topology You may wish to refer to the Mechanical Model section of the Workbench Help for additional information about this Workbench component system.

External Model Component System When an External Model component system is incorporated into model-to-model assembly, certain restrictions arise. Any suppressed bodies from other upstream systems can be unsuppressed in the downstream environment provided they were meshed prior to being suppressed in the upstream system. However, suppressed parts from other upstream systems can never be unsuppressed in the downstream environment when using the External Model component system. These restrictions also apply when using the options Unsuppress All Bodies and/or Invert Suppressed Body Set. See the Mesh-Based Geometry section of the Mechanical Help for additional specification requirements for working with .cdb files as well as the External Model component system in the Workbench Help.

Associativity of Properties During model assembly, the properties assigned to bodies in upstream systems are automatically transferred to the downstream systems. For multi-body parts, although the properties assigned to each body are transferred, the properties assigned to the parts themselves are not transferred. During refresh operations, when upstream data is modified and the downstream system is refreshed, the properties assigned to bodies in the downstream system are automatically updated, with the following exceptions: • Name • Suppression state 400

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Rigid Bodies • Shell Thickness • Shell Offset These properties do not update if you modify them in the downstream system.

Note It is recommended that you define all mesh controls and settings in your upstream systems. Mesh settings on upstream systems take priority over any downstream mesh settings. That is, any changes to an upstream system will overwrite your mesh setting changes on your downstream system once updated. As a result, you could see differences between the assembled mesh and the settings of the downstream meshed model. Therefore, to have your downstream mesh to be updated per the mesh setting changes, you need to re-mesh your downstream model once it has been refreshed. Mesh transfer will fail on assembled models if mesh controls are present in the downstream system. As needed, you can define mesh controls on the downstream system once you have assembled the model.

Rigid Bodies You can declare the stiffness behavior of a single solid body (a body that is not a component of a multibody part), a body group, surface bodies, and 2D models to be rigid or flexible. A rigid body will not deform during the solution. This feature is useful if a mechanism has only rigid body motion or, if in an assembly, only some of the parts experience most of the strains. It is also useful if you are not concerned about the stress/strain of that component and wish to reduce CPU requirements during meshing or solve operations. To set the stiffness behavior in the Mechanical application 1.

Select a body in the tree.

2.

In the Details view, set Stiffness Behavior to Rigid or Flexible.

To define a rigid body, set the field of the Details view to Rigid when the body object is selected in the tree. If rigid, the body will not be meshed and will internally be represented by a single mass element during the solution. (The mass element’s mass and inertial properties will be maintained.) The mass, centroid, and moments of inertia for each body can be found in the Details view of the body object. The following restrictions apply to rigid bodies: • Rigid bodies are only valid in static structural, Transient Structural, Rigid Dynamics, and modal analyses for the objects listed below. Animated results are available for all analysis types except modal. – Point mass – Joint – Spring – Remote Displacement

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Specifying Geometry – Remote Force – Moment – Contact • Rigid bodies are valid when scoped to solid bodies, surface bodies, or line bodies in Explicit Dynamics Analysis (p. 155) for the following objects: – Fixed Support – Displacement – Velocity The following outputs are available for rigid bodies, and are reported at the centroid of the rigid body: • Results: Displacement, Velocity, and Acceleration • Probes: Deformation, Position, Rotation, Velocity, Acceleration, Angular Velocity, and Angular Acceleration

Note • If you highlight Deformation results in the tree that are scoped to rigid bodies, the corresponding rigid bodies in the Geometry window are not highlighted. • You cannot define a line body, 2D plane strain body, or 2D axisymmetric body as rigid, except that in an Explicit Dynamics analysis, 2D plane strain and 2D axisymmetric bodies may be defined as rigid. • All bodies in a body group (of a multibody part) must have the same Stiffness Behavior. When Stiffness Behavior is Rigid, the body group acts as one rigid mass regardless of whether or not the underlying bodies are topologically connected (via shared topology).

2D Analyses The Mechanical application has a provision that allows you to run structural and thermal problems that are strictly two-dimensional (2D). For models and environments that involve negligible effects from a third dimension, running a 2D simulation can save processing time and conserve machine resources. You can specify a 2D analysis only when you attach a model. Once attached, you cannot change from a 2D analysis to a 3D analysis or vice versa. You can configure Workbench for a 2D analysis by: 1.

Creating or opening a surface body model in DesignModeler or opening a surface body model in any supported CAD system that has provisions for surface bodies. The model must be in the x-y plane. 2D planar bodies are supported; 2D wire bodies are not.

2.

Then, with the Geometry cell selected in the Project Schematic, expose the properties details of the geometry using the toolbar View drop-down menu, and choose 2D in the Analysis Type drop-down menu (located under Advanced Geometry Options).

3.

Attach the model into the Mechanical application by double-clicking on the Model cell.

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2D Analyses A 2D analysis has the following characteristics: • For Geometry items in the tree, you have the following choices located in the 2D Behavior field within the Details view: – Plane Stress (default): Assumes zero stress and non-zero strain in the z direction. Use this option for structures where the z dimension is smaller than the x and y dimensions. Example uses are flat plates subjected to in-plane loading, or thin disks under pressure or centrifugal loading. A Thickness field is also available if you want to enter the thickness of the model. – Axisymmetric: Assumes that a 3D model and its loading can be generated by revolving a 2D section 360o about the y-axis. The axis of symmetry must coincide with the global y-axis. The geometry has to lie on the positive x-axis of the x-y plane. The y direction is axial, the x direction is radial, and the z direction is in the circumferential (hoop) direction. The hoop displacement is zero. Hoop strains and stresses are usually very significant. Example uses are pressure vessels, straight pipes, and shafts. – Plane Strain: Assumes zero strain in the z direction. Use this option for structures where the z dimension is much larger than the x and y dimensions. The stress in the z direction is non-zero. Example uses are long, constant, cross-sectional structures such as structural line bodies. Plane Strain behavior cannot be used in a thermal analysis (steady-state or a transient).

Note Since thickness is infinite in plane strain calculations, different results (displacements/stresses) will be calculated for extensive loads (that is, forces/heats) if the solution is performed in different unit systems (MKS vs. NMM). Intensive loads (pressure, heat flux) will not give different results. In either case, equilibrium is maintained and thus reactions will not change. This is an expected consequence of applying extensive loads in a plane strain analysis. In such a condition, if you change the Mechanical application unit system after a solve, you should clear the result and solve again.

– Generalized Plane Strain: Assumes a finite deformation domain length in the z direction, as opposed to the infinite value assumed for the standard Plane Strain option. Generalized Plane Strain provides more practical results for deformation problems where a z direction dimension exists, but is not considerable. See Using Generalized Plane Strain (p. 404) for more information. Generalized Plane Strain needs the following three types of data: → Fiber Length: Sets the length of the extrusion. → End Plane Rotation About X: Sets the rotation of the extrusion end plane about the x-axis. → End Plane Rotation About Y: Sets the rotation of the extrusion end plane about the y-axis. – By Body: Allows you to set the Plane Stress (with Thickness option), Plane Strain, or Axisymmetric options for individual bodies that appear under Geometry in the tree. If you choose By Body, then click on an individual body, these 2D options are displayed for the individual body. • For a 2D analysis, use the same procedure for applying loads and supports as you would use in a 3D analysis. The loads and results are in the x-y plane and there is no z component.

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Specifying Geometry • You can apply all loads and supports in a 2D analysis except for the following: Line Pressure, Simply Supported, and Fixed Rotation. • A Pressure load can only be applied to an edge. • A Bearing Load and a Cylindrical Support can only be applied to a circular edge. • For analyses involving axisymmetric behavior, a Rotational Velocity load can only be applied about the y-axis. • For loads applied to a circular edge, the direction flipping in the z axis will be ignored. • Only Plain Strain and Axisymmetric are supported for Explicit Dynamics analyses. • Mechanical does not support Cyclic results for a 2D Analysis.

Using Generalized Plane Strain This feature assumes a finite deformation domain length in the z direction, as opposed to the infinite value assumed for standard plane strain. It provides a more efficient way to simulate certain 3D deformations using 2D options. The deformation domain or structure is formed by extruding a plane area along a curve with a constant curvature, as shown below. Y Starting Plane

Starting Point Ending Plane X Fiber Direction Z

Ending Point

The extruding begins at the starting (or reference) plane and stops at the ending plane. The curve direction along the extrusion path is called the fiber direction. The starting and ending planes must be perpendicular to this fiber direction at the beginning and ending intersections. If the boundary conditions and loads in the fiber direction do not change over the course of the curve, and if the starting plane and ending plane remain perpendicular to the fiber direction during deformation, then the amount of deformation of all cross sections will be identical throughout the curve, and will not vary at any curve position in the fiber direction. Therefore, any deformation can be represented by the deformation on the starting plane, and the 3D deformation can be simulated by solving the deformation problem on the starting plane. The Plane Strain and Axisymmetric options are particular cases of the Generalized Plane Strain option. All inputs and outputs are in the global Cartesian coordinate system. The starting plane must be the xy plane, and must be meshed. The applied nodal force on the starting plane is the total force along the fiber length. The geometry in the fiber direction is specified by the rotation about the x-axis and y-axis of the ending plane, and the fiber length passing through a user-specified point on the starting plane called the starting or reference point. The starting point creates an ending point on the ending plane through the extrusion process. The boundary conditions and loads in the fiber direction are specified by applying displacements or forces at the ending point.

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Symmetry The fiber length change is positive when the fiber length increases. The sign of the rotation angle or angle change is determined by how the fiber length changes when the coordinates of the ending point change. If the fiber length decreases when the x coordinate of the ending point increases, the rotation angle about y is positive. If the fiber length increases when the y coordinate of the ending point increases, the rotation angle about x is positive. For linear buckling and modal analyses, the Generalized Plane Strain option usually reports fewer Eigenvalues and Eigenvectors than you would obtain in a 3D analysis. Because it reports only homogeneous deformation in the fiber direction, generalized plane strain employs only three DOFs to account for these deformations. The same 3D analysis would incorporate many more DOFs in the fiber direction. Because the mass matrix terms relating to DOFs in the fiber direction are approximated for modal and transient analyses, you cannot use the lumped mass matrix for these types of simulations, and the solution may be slightly different from regular 3D simulations when any of the three designated DOFs is not restrained. Overall steps to using Generalized Plane Strain 1.

Attach a 2D model in the Mechanical application.

2.

Click on Geometry in the tree.

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In the Details view, set 2D Behavior to Generalized Plane Strain.

4.

Define extrusion geometry by providing input values for Fiber Length, End Plane Rotation About X, and End Plane Rotation About Y.

5.

Add a Generalized Plane Strain load under the analysis type object in the tree.

Note The Generalized Plane Strain load is applied to all bodies. There can be only one Generalized Plane Strain load per analysis type so this load will not be available in any of the load drop-down menu lists if it has already been applied.

6.

In the Details view, input the x and y coordinates of the reference point , and set the boundary conditions along the fiber direction and rotation about the x and y-axis.

7.

Add any other loads or boundary conditions that are applicable to a 2D model.

8.

Solve. Reactions are reported in the Details view of the Generalized Plane Strain load.

9.

Review results.

Symmetry You can use the inherent geometric symmetry of a body to model only a portion of the body for simulation. Using symmetry provides the benefits of faster simulation times and less use of system resources. For example, the model below can be simplified by modeling only ¼ of the geometry by taking advantage of two symmetry planes.

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Specifying Geometry

Introduction Making use of the Symmetry feature requires an understanding of the geometry symmetry and the symmetry of loading and boundary conditions. If geometric symmetry exists, and the loading and boundary conditions are suitable, then the model can be simplified to just the symmetry sector of the model. DesignModeler can be used to simplify a full model into a symmetric model. This is done by identifying symmetry planes in the body. DesignModeler will then slice the full model and retain only the symmetry portion of the model. (See Symmetry in the DesignModeler help). To further understand the use of Symmetry in the Mechanical application, examine the following topics: Types of Regions Symmetry Defined in DesignModeler Symmetry in the Mechanical Application

Types of Regions When the Mechanical application attaches to a symmetry model from DesignModeler, a Symmetry folder is placed in the tree and each Symmetry Plane from DesignModeler is given a Symmetry Region object in the tree. In addition, Named Selection objects are created for each symmetry edge or face. (See Symmetry Defined in DesignModeler (p. 425).) The Symmetry folder supports the following objects: • Symmetry Region – supported for structural analyses. • Periodic Region – supported for magnetostatic analyses.

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Symmetry • Cyclic Region – supported for structural and thermal analyses.

Note Periodic and Cyclic regions: • Support 3D analyses only • Ensure that a mesh is cyclic and suitable for fluids analyses (the mesh is then matched, however, users must re-assign periodic regions in the solver).

For models generated originally as symmetry models, you may create a Symmetry folder and manually identify Symmetry Region objects or Periodic/Cyclic Region objects. (See Symmetry in the Mechanical Application (p. 426).)

Symmetry Region A symmetry region refers to dimensionally reducing the model based on a mirror plane. Symmetry regions are supported for: • Structural Symmetry • Structural Anti-Symmetry • Structural Linear Periodic Symmetry • Electromagnetic Symmetry • Electromagnetic Anti-Symmetry • Explicit Dynamics Symmetry

Structural Symmetry A symmetric structural boundary condition means that out-of-plane displacements and in-plane rotations are set to zero. The following figure illustrates a symmetric boundary condition. Structural symmetry is applicable to solid and surface bodies.

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Specifying Geometry

Structural Anti-Symmetry An anti-symmetric boundary condition means that the rotation normal to the anti-symmetric face is constrained. The following figure illustrates an anti-symmetric boundary condition. Structural antisymmetry is applicable to solid and surface bodies.

Note The Anti-Symmetric option does not prevent motion normal to the symmetry face. This is appropriate if all loads on the structure are in-plane with the symmetry plane. If applied loads, or loads resulting from large deflection introduce force components normal to the face, an additional load constraint on the normal displacement may be required.

Structural Linear Periodic Symmetry The Linear Periodic Boundary condition is used to simulate models with translational symmetry, where the structure is assumed to repeat itself in one particular direction to infinity. This feature supports only a single direction for the entire model (more than one direction is not supported). The application uses the MAPDL command CE to solve this boundary condition.

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Symmetry

Electromagnetic Symmetry Symmetry conditions exist for electromagnetic current sources and permanent magnets when the sources on both sides of the symmetry plane are of the same magnitude and in the same direction as shown in the following example.

Electromagnetic symmetric conditions imply Flux Normal boundary conditions, which are naturally satisfied.

Electromagnetic Anti-Symmetry Anti-Symmetry conditions exist for electromagnetic current sources and permanent magnets when the sources on both sides of the symmetry plane are of the same magnitude but in the opposite direction as shown in the following example.

Electromagnetic anti-symmetric conditions imply Flux Parallel boundary conditions, which you must apply to selected faces.

Explicit Dynamics Symmetry Symmetry regions can be defined in explicit dynamics analyses. Symmetry objects should be scoped to faces of flexible bodies defined in the model. All nodes lying on the plane, defined by the selected face are constrained to give a symmetrical response of the structure.

Note • Anti-symmetry, periodicity and anti-periodicity symmetry regions are not supported in Explicit Dynamics systems. • Symmetry cannot be applied to rigid bodies.

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Specifying Geometry • Only the General Symmetry interpretation is used by the solver in 2D Explicit Dynamics analyses.

Symmetry conditions can be interpreted by the solver in two ways: General Symmetry Global Symmetry Planes

General Symmetry In general, a symmetry condition will result in degree of freedom constraints being applied to the nodes on the symmetry plane. For volume elements, the translational degree of freedom normal to the symmetry plane will be constrained. For shell and beam elements, the rotational degrees of freedom in the plane of symmetry will be additionally constrained. For nodes which have multiple symmetry regions assigned to them (for example, along the edge between two adjacent faces), the combined constraints associated with the two symmetry planes will be enforced.

Note • Symmetry regions defined with different local coordinate systems may not be combined, unless they are orthogonal with the global coordinate system. • General symmetry does not constrain eroded nodes. Thus, if after a group of elements erodes, a “free” eroded node remains, the eroded node will not be constrained by the symmetry condition. This can be resolved in certain situations via the special case of Global symmetry, described in the next section.

Global Symmetry Planes If a symmetry object is aligned with the Cartesian planes at x=0, y=0 or z=0, and all nodes in the model are on the positive side of x=0, y=0, or z=0, the symmetry condition is interpreted as a special case termed Global symmetry plane. In addition to general symmetry constraints: • If a symmetry plane is coincident with the YZ plane of the global coordinate system (Z=0), and no parts of the geometry lie on the negative side of the plane, then a symmetry plane is activated at X=0. This will prevent any nodes (including eroded nodes) from moving through the plane X=0 during the analysis. • If a symmetry plane is coincident with the ZX plane of the global coordinate system (Y=0), and no parts of the geometry lie on the negative side of the plane, then a symmetry plane is activated at Y=0. This will prevent any nodes (including eroded nodes) from moving through the plane Y=0 during the analysis. • If a symmetry plane is coincident with the XY plane of the global coordinate system (Z=0), and no parts of the geometry lie on the negative side of the plane, then a symmetry plane is activated at Z=0. This will prevent any nodes (including eroded nodes) from moving through the plane Z=0 during the analysis.

Note Global symmetry planes are only applicable to 3D Explicit Dynamics analyses.

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Periodic Region The Periodic Region object is used to define for Electromagnetic analysis Periodical or Anti–Periodical behavior in a particular model (see Electromagnetic Periodic Symmetry section).

Electromagnetic Periodicity A model exhibits angular periodicity when its geometry and sources occur in a periodic pattern around some point in the geometry, and the repeating portion that you are modeling represents all of the sources, as shown below (see the Periodicity Example (p. 412)).

Electromagnetic Anti-Periodicity A model exhibits angular anti-periodicity when its geometry and sources occur in a periodic pattern around some point in the geometry and the repeating portion that you are modeling represents a subset of all of the sources, as shown below.

Electromagnetic Periodic Symmetry Electric machines and generators, solenoid actuators and cyclotrons are just a few examples of numerous electromagnetic devices that exhibit circular symmetrical periodic type of symmetry. An automated periodic symmetry analysis conserves time and CPU resources and delivers analysis results that correspond to the entire structure. The overall procedure in ANSYS Workbench for simulating structures that are periodically symmetric is to run a magnetostatic analysis and perform the following specialized steps:

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Specifying Geometry 1. Insert a Periodic Region symmetry object in the tree. This step is necessary to enable ANSYS Workbench to perform a periodic symmetry analysis. 2. Define the low and high boundaries of the Periodic Region by selecting the appropriate faces in the Low Boundary and High Boundary fields. 3. Define type of symmetry as Periodic or Anti-Periodic (see Periodicity Example (p. 412)). 4. The solver will automatically take into account defined periodicity, and reported results will correspond to the full symmetry model (except volumetric type results as Force Summation, Energy probe, and so on).

Note For a magnetic field simulation with periodic regions, you must be careful when applying flux parallel boundary conditions to adjoining faces. If the adjoining faces of the periodic faces build up a ring and all are subject to flux parallel conditions, that implies a total flux of zero through the periodic face. In some applications that is not a physically correct requirement. One solution is to extend the periodic sector to include the symmetry axis.

See the Periodicity Example (p. 412) section for further details.

Periodicity Example Periodicity is illustrated in the following example. A coil arrangement consists of 4 coils emulated by stranded conductors. A ½ symmetry model of surrounding air is created. The model is conveniently broken into 16 sectors for easy subdivision into periodic sectors and for comparison of results.

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Symmetry Below is a display of the Magnetic Field Intensity for the ½ symmetry model at the mid-plane. The arrows clearly indicate an opportunity to model the domain for both Periodic or Anti-periodic sectors. Periodic planes are shown to exist at 180 degree intervals. Anti-periodic planes are shown to exist at 90 degree intervals.

The model can be cut in half to model Periodic planes. Applying periodic symmetry planes at 90 degrees and 270 degrees leads to the following results.

The model can be cut in half again to model Anti-Periodic planes. Applying anti-periodic symmetry planes at 0 degrees and 90 degrees leads to the following results.

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Specifying Geometry

Cyclic Region Fan wheels, spur gears, and turbine blades are all examples of models that can benefit from cyclic symmetry. An automated cyclic symmetry analysis conserves time and CPU resources and allows you to view analysis results on the entire structure (for a structural analysis). ANSYS Workbench automates cyclic symmetry analysis by: • Solving for the behavior of a single symmetric sector (part of a circular component or assembly). See The Basic Sector in the Advanced Analysis Guide for more information. • Using the single-sector solution to construct the response behavior of the full circular component or assembly (as a postprocessing step). For example, by analyzing a single 10° sector of a 36-blade turbine wheel assembly, you can obtain the complete 360° model solution via simple postprocessing calculations. Using twice the usual number of degrees of freedom (DOFs) in this case, the single sector represents a 1/36th part of the model.

Note • Layered Sections cannot be applied to a model that uses cyclic symmetry. • Mechanical 2D Analyses do not support cyclic results.

The overall procedure in ANSYS Workbench for simulating models that are cyclically symmetric is to run a static structural, modal, or thermal analysis and perform the following specialized steps: 1. Insert a Cyclic Region symmetry object in the tree. This step is necessary to enable ANSYS Workbench to perform a cyclic symmetry analysis. Multiple Cyclic Region objects are permitted but they must refer to the same Coordinate System to specify the symmetry axis. 2. Define the low and high boundaries of the Cyclic Region by selecting the appropriate faces in the Low Boundary and High Boundary fields. Each selection can consist of one or more faces over one or more parts, but they must be paired properly. To be valid, each face in Low Boundary must be accompanied by its twin in High Boundary. Also, ensure that each face and its twin belong to the same multibody part (although it is not necessary that they belong to the same body), using DesignModeler to adjust your multibody parts as needed. Your selections will be used to match the mesh of these two boundaries. The example shown below illustrates two equally valid Low Boundary and High Boundary twin faces. One twin set of faces, located in the corner body, includes faces that are both included in that same body. Another twin set includes faces that are not on the same body, but are included in the same multibody part, as shown in the second figure.

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Symmetry

Note High Boundary and Low Boundary should be exactly same in shape and size, otherwise Mechanical will not be able to map nodes from Low Boundary to High Boundary to create full model from a single sector.

3. Continue with the remainder of the analysis. Consult the sections below as applicable to the analysis type. Refer to the following sections for further details on cyclic symmetry: Cyclic Symmetry in a Static Structural Analysis Cyclic Symmetry in a Modal Analysis Cyclic Symmetry in a Thermal Analysis

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Cyclic Symmetry in a Static Structural Analysis When you perform a static structural analysis that involves cyclic symmetry, unique features are available for loads/supports and reviewing results. These features are described in the following sections: Applying Loads and Supports for Cyclic Symmetry in a Static Structural Analysis Reviewing Results for Cyclic Symmetry in a Static Structural Analysis

Applying Loads and Supports for Cyclic Symmetry in a Static Structural Analysis The following support limitations and specifications must be observed: • The following boundary conditions are not supported: – Bearing Load – Hydrostatic Pressure – Fluid Solid Interface • The following remote boundary conditions are not supported: – Joints – Bearing • Inertial boundary conditions and the Moment boundary condition are restricted to the axial direction. To comply, Acceleration, Standard Earth Gravity, Rotational Velocity, and Moment must be defined by components: only the Z component can be non-zero and the Coordinate System specified must match that used in the Cyclic Region. Additional restrictions apply while specifying supports for a static structural analysis. For example, Elastic Supports and Compression Only Supports are not available. Also, the loads and supports should not include any face selections (for example, on 3D solids) that already belong to either the low or high boundaries of the cyclic symmetry sector. Loads and supports may include edges (for example, on 3D solids) on those boundaries, however.

Note If you scope a Remote Force or Moment boundary condition to a Remote Point that is located on the cyclic axis of symmetry, it is necessary that the Remote Point be constrained by a Remote Displacement in order to obtain accurate results. Furthermore, non-physical results might be exposed if the remote boundary conditions specify the Behavior option as Deformable. Loads and supports are assumed to have the same spatial relation for the cyclic axis in all sectors. In preparation for solution, the boundary conditions on the geometry are converted into node constraints in the mesh (see Converting Boundary Conditions to Nodal DOF Constraints (Mechanical APDL Solver) (p. 1135) for more information). When these boundary conditions involve nodes along the sector boundaries (low, high, and axial boundaries), their constraints are integrated to properly reflect the symmetry. As an example, the low and high edges may feature more node constraints than are applied to each individually, in order to remain consistent with an equivalent full model.

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Reviewing Results for Cyclic Symmetry in a Static Structural Analysis When simulating cyclic symmetry in a static structural analysis, the same results are available as results in static structural analyses that involve full symmetry with the exception of Linearized Stresses. Even though only one cyclic sector is analyzed, results are valid for the full symmetry model. You can control the post-processing and display of cyclic results using the Cyclic Solution Display options on the Solution folder: • Number of Sectors: This option controls the extent the model is expanded from the raw solution. The value indicates how many sectors should be processed, displayed and animated. Results generate more quickly and consume less memory and file storage when fewer sectors are requested. To set the value as Program Controlled, enter zero; this value reveals the full expansion. • Starting at Sector: Selects the specific sectors to include within the expansion. For example, if Number of Sectors is set to 1, sectors 1 through N are revealed one at a time. To set the value as Program Controlled, enter zero; this value reveals the specified number of sectors from sector 1 onwards.

Note Extremum values (e.g., Minimum, Maximum) correspond only to the portion of the model selected in the Cyclic Solution Display. Unexpanded One Sector Model Display:

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Specifying Geometry Expanded Full Symmetry Model Display:

Note • The results for the Energy Probe, Force Reaction probe, and Moment Reaction probe are calculated for the full symmetry model. • Unaveraged contact results do not expand to all expanded sectors in a cyclic analysis. • Expanded result visualization is not available to the Samcef solver.

Cyclic Symmetry in a Modal Analysis When you perform a modal analysis that involves cyclic symmetry, unique features are available for loads/supports, analysis settings, and reviewing results. These features are described in the following sections: Applying Loads and Supports for Cyclic Symmetry in a Modal Analysis Analysis Settings for Cyclic Symmetry in a Modal Analysis Reviewing Results for Cyclic Symmetry in a Modal Analysis

Applying Loads and Supports for Cyclic Symmetry in a Modal Analysis The following support limitations and specifications must be observed: • Elastic Supports and Compression Only Supports are not permitted. 418

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Symmetry • Supports should not include any face selections (for example, on 3D solids) that already belong to either the low or high boundaries of the cyclic symmetry sector. Supports may include edges (for example, on 3D solids) on those boundaries, however. • Only the following remote boundary conditions are supported: – Remote Displacement – Point Mass – Spring In preparation for solution, the boundary conditions on the geometry are converted into node constraints in the mesh (see Converting Boundary Conditions to Nodal DOF Constraints (Mechanical APDL Solver) (p. 1135) for more information). When these boundary conditions involve nodes along the sector boundaries (low, high and axial boundaries), their constraints are integrated to properly reflect the symmetry. As an example, the low and high edges may feature more node constraints than are applied to each individually, in order to remain consistent with an equivalent full model. If the modal analysis is activated as pre-stressed, no other modal loads/supports are allowed. On the other hand you can apply all pertinent structural loads/supports in the previous cyclic static analysis. When using the Samcef solver, compatibility of supports with cyclic symmetry is checked internally. If an incompatibility is detected a warning or error message will be displayed, and the solve will be interrupted.

Analysis Settings for Cyclic Symmetry in a Modal Analysis A modal analysis involving cyclic symmetry includes a Cyclic Controls (p. 646) category that enables you to solve the harmonic index for all values, or for a range of values. This category is available if you have defined a Cyclic Region in the analysis.

Note Currently for Modal Analysis with Cyclic Symmetry: • The Unsymmetric Solver Type (UNSYM) is not supported. • Damping is not supported (Fully Damped, DAMPED, or Reduced Damped, QRDAMP). • Expansion is only available for harmonic indices > 0 with the Samcef solver. For more information about the associated MAPDL command, see the MODOPT section of the Mechanical APDL Command Reference.

Reviewing Results for Cyclic Symmetry in a Modal Analysis A modal analysis involving cyclic symmetry includes additional options to help you navigate and interpret the results. In particular, there are features to: • Review the complete range of modes: you may request the modes to be sorted by their serial number in the results file or by their frequency value in the spectrum. • Review combinations of degenerate modes through the complete range of phase angles. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Specifying Geometry When simulating cyclic symmetry in a modal analysis, the same results are available as for a modal analysis with full symmetry, with the exception of Linearized Stresses. Although only one cyclic sector is analyzed, results are valid for the full symmetry model. You can control the post-processing and display of cyclic results using the Cyclic Solution Display options on the Solution folder: • Number of Sectors: This option controls the extent the model is expanded from the raw solution. The value indicates how many sectors should be processed, displayed and animated. Results generate more quickly and consume less memory and file storage when fewer sectors are requested. To set the value as Program Controlled, enter zero; this value reveals the full expansion. • Starting at Sector: Selects the specific sectors to include within the expansion. For example, if Number of Sectors is set to 1, sectors 1 through N are revealed one at a time. To set the value as Program Controlled, enter zero; this value reveals the specified number of sectors from sector 1 onwards.

Note Extremum values (e.g., Minimum, Maximum) correspond only to the portion of the model selected in the Cyclic Solution Display. Because these features involve reviewing the mode shapes and contours at individual points within a range, they leverage the charting facilities of the Graph and Tabular Data windows together with the 3D contour plotting of the Graphics view. Reviewing the Complete Range of Modes You may request the modes to be sorted in the Graph window by their set number in the results file or by their frequency value in the spectrum. You may then interact with the plot to generate specific mode shapes and contours of interest. To control how modes are sorted, use the X-Axis setting under Graph Controls in the Details view of the result and set to either Mode or Frequency: • Mode: This choice will designate the x-axis in the Graph window to indicate the set numbers for each mode (within a harmonic index) in the results file. Each mode will have a vertical bar whose height represents its frequency of vibration. The columns in the Tabular Data window are displayed in the order of: Mode, Harmonic Index, and Frequency.

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Symmetry

When X-Axis is set to Mode, the Definition category includes settings for Cyclic Mode and Harmonic Index. • Frequency: This choice will designate the x-axis in the Graph window to indicate the mode Frequency. Modes are thus sorted by their frequencies of vibration. Each mode will have a vertical bar whose height, for cross-reference, corresponds to the mode number (within its harmonic index). The columns in the Tabular Data window are displayed in the order of: Frequency, Mode, and Harmonic Index.

When X-Axis is set to Frequency, the Definition category includes a setting for Cyclic Phase. Readonly displays of the Minimum Value Over Phase and the Maximum Value Over Phase are also available. • Phase: For degenerate modes or couplets, a third option for the X-Axis setting under Graph Controls is available. This choice will designate the x-axis in the Graph window to indicate the phase angle. The graph will show the variation of minimum and maximum value of the result with change in phase angle for the concerned couplet. This setting allows you to analyze the result for a particular mode (for couplets only). The columns in the Tabular Data window are displayed in the order of: Phase, Minimum and Maximum. For details on couplets, read the section below. Reviewing results for frequency couplets as a function of cyclic phase angles An inspection of the results for harmonic indices between 0 and N/2 (that is, 0 < Harmonic Index < N/2) reveals that natural frequencies are reported in pairs by the solver. These pairs of equal value are often Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Specifying Geometry termed “couplets”. The corresponding mode shapes in each couplet represent two standing waves, one based on a sine and another on a cosine solution of the same spatial frequency, thus having a phase difference of 90°. To appreciate the full range of vibrations possible at a given frequency couplet, it is necessary to review not only the individual mode shapes for sine and cosine (e.g., at 0° and 90°) but also their linear combinations which sweep a full cycle of relative phases from 0° to 360°. This sweep is displayed by Mechanical as an animation called a «traveling wave». The following is an example:

Note The following demos are presented in animated GIF format. Please view online if you are reading the PDF version of the help.

Animations for mode shapes in other harmonic indices, that is, 0 or, for N even, N/2, will yield standing waves. The following animation is an example of a standing wave.

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Symmetry

There are options to review the dependence of a result on cyclic phase angle quantitatively. For applicable harmonic indices, results can be defined by: • Cyclic Phase: Use in combination with the Cyclic Phase setting to report the contour at a specific phase. Under this setting, the result will also report the Minimum Value Over Cyclic Phase and the Maximum Value Over Cyclic Phase. • Maximum over Cyclic Phase: this contour reveals the peak value of the result as a function of cyclic phase for every node/element. • Cyclic Phase of Maximum: this contour reveals the cyclic phase at which the peak value of the result is obtained for every node/element. When the result is defined by Cyclic Phase, it may be convenient to use the interaction options to pick the value of phase from the Tabular Data window as an alternative to direct input in the Details view. To access this feature, set the X-Axis to Phase under Graph Controls. To control the density of the cyclic phase sweep, choose Tools> Options from the main menu, then under Mechanical choose Frequency and Cyclic Phase Number of Steps. The phase sweep can be disabled individually on a result by setting Allow Phase Sweep to No in the Details view.

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Interaction Options The Graph, Tabular Data and the Graphics view can be used in concert while reviewing modal cyclic results. For example, if you click in the Tabular Data window, a black vertical cursor moves to the corresponding position in the chart. Conversely, if you click on a bar (for Mode or Frequency display) or a node in the chart (for a Phase display), the corresponding row is highlighted in the Tabular Data window. Multi-selection is also available by dragging the mouse over a range of bars or nodes (in the chart) or rows in the Tabular Data window. These are useful in identifying the mode number and harmonic index with specific values of the frequency spectrum.

Also, the Graph or Tabular Data windows can be used to request a specific mode shape at a phase value of interest (if applicable) using context sensitive options. To access these, select an item in the Graph or Tabular Data windows and click the right mouse button. The following are the most useful options: • Retrieve This Result: Auto-fills the Mode and Harmonic Index ( for a Mode or Frequency display) or the Phase angle (for a Phase display) into the Details view of the result and will force the evaluation of the result with the parameters that were recently changed. • Create Mode Shape Results: processes the selected pairs (Mode, Harmonic Index defined by dragging in the Graph window to produce a light blue rectangle) and inserts results under the Solution folder. You must then evaluate these results, since they are not evaluated automatically. This option is not available for Phase display. The following two options are available only if you click the right mouse button in the Graph window:

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Symmetry • Zoom to Range: Zooms in on a subset of the data in the Graph window. Click and hold the left mouse at a step location and drag to another step location. The dragged region will highlight in blue. Next, select Zoom to Range. The chart will update with the selected step data filling the entire axis range. This also controls the time range over which animation takes place. • Zoom to Fit: If you have chosen Zoom to Range and are working in a zoomed region, choosing Zoom to Fit will return the axis to full range covering all steps.

Cyclic Symmetry in a Thermal Analysis When you perform a steady state thermal analysis or transient thermal analysis that involves cyclic symmetry, unique features are available for loads/supports and reviewing results. These features are described in the following sections: Applying Loads for Cyclic Symmetry in a Thermal Analysis Reviewing Results for Cyclic Symmetry in a Thermal Analysis

Applying Loads for Cyclic Symmetry in a Thermal Analysis For a thermal analysis, in the presence of cyclic symmetry, Coupling loads are not available. Also, loads should not include any face selections (for example, on 3D solids) that already belong to either the low or high boundaries of the cyclic symmetry sector. Loads may include edges (for example, on 3D solids) on those boundaries, however. Loads are assumed to have the same spatial relation for the cyclic axis in all sectors. In preparation for solution, the boundary conditions on the geometry are converted into node constraints in the mesh (see Converting Boundary Conditions to Nodal DOF Constraints (Mechanical APDL Solver) (p. 1135) for more information). When these boundary conditions involve nodes along the sector boundaries (low, high and axial boundaries), their constraints are integrated to properly reflect the symmetry. As an example, the low and high edges may feature more node constraints than are applied to each individually, in order to remain consistent with an equivalent full model.

Reviewing Results for Cyclic Symmetry in a Thermal Analysis When simulating cyclic symmetry in a thermal analysis, the same results are available as results in a thermal analysis that involve full symmetry.

Note Radiation Probe results are calculated for the full symmetry model.

Symmetry Defined in DesignModeler The following procedure describes the steps use to working with Symmetry in DesignModeler. 1. While in DesignModeler, from the Tools menu, apply the Symmetry feature to the model or define an Enclosure. 2. Enter the Mechanical application by double-clicking on the Model cell in the Project Schematic. The Mechanical application screen appears and includes the following objects in the tree: • A Symmetry object. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Specifying Geometry • Symmetry Region objects displayed under the Symmetry folder. The number of Symmetry Region objects corresponds to the number of symmetry planes you defined in DesignModeler. • A Named Selections folder object. Each child object displayed under this folder replicates the enclosure named selections that were automatically created when you started the Mechanical application. 3. In the Details view of each Symmetry Region object, under Definition, specify the type of symmetry by first clicking on the Type field, then choosing the type from the drop down list. Boundary conditions will be applied to the symmetry planes based on both the simulation type and what you specify in the symmetry Type field. The Scope Mode read-only indication is Automatic when you follow this procedure of defining symmetry in DesignModeler. The Coordinate System and Symmetry Normal fields include data that was “inherited” from DesignModeler. You can change this data if you wish. The Symmetry Normal entry must correspond to the Coordinate System entry.

Symmetry in the Mechanical Application The following procedure describes the steps that you’ll use to implement feature during an analysis using the Mechanical Application. 1. Insert a Symmetry object in the tree. 2. Insert a Symmetry Region object, a Periodic Region object, or a Cyclic Region object to represent each symmetry plane you want to define. Refer to Symmetry Region (p. 407) to determine which object to insert. 3. For each Symmetry Region object or Periodic/Cyclic Region object, complete the following in the Details view: a. Scoping Method — Perform one of the following: • Choose Geometry Selection if you want to define a symmetry plane by picking in the Geometry window. Pick the geometry, then click on the entry field for Geometry Selection (labeled No Selection) and click the Apply button. For a Periodic/Cyclic Region object or for a Symmetry object whose Type is specified as Linear Periodic, select the appropriate faces/edges in the Low Boundary and High Boundary fields. Each selection can consist of one or more faces over one or more parts, but they must be paired properly. To be valid, each face/edge in Low Boundary must be accompanied by its twin in High Boundary. Also, ensure that each face/edge and its twin belong to the same multibody part (although it is not necessary that they belong to the same body), using DesignModeler to adjust your multibody parts as needed. Your selections will be used to match the mesh of these two boundaries.

Note A Symmetry Region object can only be scoped to a flexible body.

• Choose Named Selection if you want to define a symmetry plane using geometry that was predefined in a named selection. Click on the entry field for Named Selection and, from the drop down list, choose the particular named selection to represent the symmetry plane. For a Periodic/Cyclic Region object, you perform the same procedure, where Low Selection corresponds to the Low Boundary component and High Selection corresponds to the High Boundary component.

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Symmetry b. The Scope Mode read-only indication is Manual when you follow this procedure of defining symmetry directly in the Mechanical application. c. Type — For a Symmetry Region or Periodic Region only, click on the entry field, and, from the drop down list, choose the symmetry type. Boundary conditions will be applied to the symmetry planes based on both the simulation type and the value you specify in the symmetry Type field. d. Coordinate System — Select an appropriate coordinate system from the drop down list. You must use a Cartesian coordinate system for a Symmetry Region. The Periodic/Cyclic Region require a cylindrical coordinate system. See the Coordinate Systems section, Initial Creation and Definition, for the steps to create a local coordinate system. e. Symmetry Normal — For a Symmetry Region object only, specify the normal axis from the drop down list that corresponds to the coordinate system that you chose. f.

Periodicity Direction — For a Linear Periodic Symmetry Region object only. This axis should point into the direction (in user selected Coordinate System) the model should be translated. It might be different from Symmetry Normal property used for other Symmetry Region types.

g. Linear Shift — For a Linear Periodic Symmetry Region object only. This property value (positive or negative) represents the nodes location increments in chosen Periodicity Direction. h. Suppressed — Include (No — default) or exclude (Yes) the boundary condition. The following example shows a body whose Symmetry Region was defined in the Mechanical application.

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Note You can select multiple faces to work with a symmetry region. For Symmetric/Anti-Symmetric Symmetry Regions, all faces selected (or chosen through Named Selection folder) must have only one normal. For periodic/cyclic types, you should additionally choose the proper cylindrical coordinate system with the z-axis showing the rotation direction, similar to the Matched Face Mesh meshing option. For Symmetry Region with Linear Periodic type, you should in turn choose the proper Cartesian coordinate system with the Periodicity Direction and Linear Shift properties showing pertinent values to facilitate conditions similar to the Arbitrary Match Control meshing option. The following example shows a body whose Periodic Region was defined in the Mechanical application.

The following example shows a body whose Cyclic Region was defined in the Mechanical application.

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Named Selections

Note When using a Periodic/Cyclic Region or for a Symmetry object whose Type is specified as Linear Periodic, the mesher automatically sets up match face meshing on the opposite Low Boundary and High Boundary faces. A useful feature available is the ability to swap Low Boundary and High Boundary settings under Scope in the Details view. You accomplish this by clicking the right mouse button on the specific symmetry regions (Ctrl key or Shift key for multiple selections) and choosing Flip High/Low.

Note Except for cyclic symmetry models, symmetry models will not deform for unaveraged results. For example, for an unaveraged stress display, you will see the undeformed shape of the model.

Named Selections The Named Selection feature allows you to create groupings of similar geometry or meshing entities. The section describes the steps to create Named Selections objects and prepare them for data definition. Subsequent sections further define and build upon these techniques, and include: Defining Named Selections Promoting Scoped Objects to a Named Selection Displaying Named Selections Using Named Selections Displaying Interior Mesh Faces Converting Named Selection Groups to Mechanical APDL Application Components

Create a Named Selection Object Creating Named Selections objects is easy and can be accomplished by several different methods, including: • Select the Model object and click the Named Selection button on the Model Context Toolbar or select the Model object, right-click the mouse, and then select Insert>Named Selection.

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• Select desired geometry entities from the Geometry object, right-click the mouse, and then select Create Named Selection. A Selection Name window appears so that you can enter a specific name for the Named Selection.

• Select desired geometry entities in the graphical interface (bodies, faces, etc. — bodies are show below), right-click the mouse, and then select Create Named Selection. A Selection Name window appears so that you can enter a specific name for the Named Selection as well as specify criteria based on the selected geometry.

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Named Selections

As illustrated below, these methods, by default, place a Named Selections folder object into the tree that includes a child object titled Selection or titled with a user-defined name. This new object, and any subsequent named selection objects that are inserted into the parent folder, require geometry or mesh entity scoping. If a direct selection method (via Geometry object or graphical selection) was used, the Geometry entities may already be defined. The Selection objects are the operable “named selections” of your analysis. You may find it beneficial to rename these objects based on the entities to which they are scoped or the purpose that they will serve in the analysis. For example, you may wish to rename a Named Selection containing edges to «Edges for Contact Region».

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Adding Named Selection Objects If a Named Selections folder object exists in the tree, insert additional Named Selection objects using the same general methods as above: (1) click the Named Selection button on the Named Selection context toolbar (available once the Named Selection folder is generated) or (2) when either the Named Selections parent folder object or another Selection object is highlighted, right-click the mouse and select Insert>Named Selection.

Defining Named Selections The following sections describe the methods used to define the characteristics of your Named Selection, such as geometry, and include: Specifying Named Selections by Geometry Type Specifying Named Selections using Worksheet Criteria

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Named Selections

Specifying Named Selections by Geometry Type Once you create Named Selections/Selection objects, you need to define the geometry or node-based meshing entities that you would like to scope to the object. Scoping method options include: • Geometry — geometry-based, node-based, element-based entries/selections • Worksheet — criteria-based entries/selections. Use the steps shown below to define the Details of your Named Selections based on geometry types (body, face, edge, or vertex). To scope your Named Selection to nodes or elements or by using the Worksheet, see one of the following sections: • Specifying Named Selections by Direct Node Selection (p. 101) • Specifying Element-Based Named Selections (p. 104) • Specifying Named Selections using Worksheet Criteria (p. 434)

Named Selections Defined by Geometry Types To define geometry-based named selections: 1. Highlight the Selection object in the tree. In the Details view, set Scoping Method to Geometry Selection. 2. Select the geometry entities in the graphics window to become members of the Named Selection. 3. Click in the Geometry field in the details view, then click the Apply button. The named selection is indicated in the graphics window. You can rename the object by right-clicking on it and choosing Rename from the context menu.

Tip To allow the Named Selection criteria to be automatically generated after a geometry update, highlight the Named Selections folder object and set Generate on Refresh to Yes (default). This setting is located under the Worksheet Based Named Selections category in the Details view.

Note • If you change the Scoping Method from Geometry Selection to Worksheet, the original geometry scoping remains until you select Generate. • For geometric entity Named Selections, the status of a Named Selection object can be fully defined (check mark) only when a valid geometry is applied, or suppressed (“x”) if either no geometry is applied or if all geometry applied to the Named Selection is suppressed. • For a Named Selection created using the Graphics Viewer, the selections must be manually updated after you change the geometry.

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Specifying Named Selections using Worksheet Criteria As described in the Specifying Named Selections by Geometry Type (p. 433) section, you can specify the Worksheet as your Scoping Method. Worksheet data defines the criteria for Named Selections based on geometric or meshing entities. Each row of the worksheet performs a calculation for the specified criteria. If multiple rows are defined, the calculations are evaluated and completed in descending order.

Named Selections Defined by Worksheet Criteria To define named selections using Worksheet criteria: 1. Highlight the Selection object. In the Details view, set Scoping Method to Worksheet. 2. As needed, right-click the mouse and select Add Row. 3. Enter data in the worksheet for specifying the criteria that will define a Named Selection. See the Worksheet Entries and Operation section below for specific entry information. 4. Click the Generate button located on the Worksheet to create the Named Selection based on the specified criteria. Alternatively, you can right-click on the Named Selection object and choose Generate Named Selection from the context menu.

Note • If you change the Scoping Method from Geometry Selection to Worksheet, the original geometry scoping will remain until you select Generate. • When you select Generate and the generation fails to produce a valid selection, any prior scoping is removed and the Named Selection. • If there is no indication that the worksheet has been changed and the Named Selection should be regenerated, you still may want to select Generate to ensure that the item is valid. • If a row inside the worksheet has no effect on the selection, there are no indications related to this. • Named Selections require valid scoping. If the application detects a criterion that is not properly scoped, it becomes highlighted in yellow to alert users of a possible problem. A highlighted criterion does not effect on the overall state of the object.

Worksheet Entries and Operation A sample worksheet is illustrated below.

Once a row has been placed in the Worksheet, the right-click context menu activates options to Insert additional rows, Modify rows, and/or Delete rows.

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Named Selections Criteria of the Worksheet is defined by making selections in the drop-down menus of the columns for each row. Certain values are read-only or they are only available as the result of other criterion being specified. The content of each Worksheet column is described below. Action column: • Add: Adds the information defined in the current row to information in the previous row, provided the item defined in the Entity Type column is the same for both rows. • Remove: Removes the information defined in the current row from information in the previous row, provided the geometry defined in the Entity Type column is the same for both rows. • Filter: Establishes a subset of the information defined in the previous row. • Invert: Selects all items of the same Entity Type that are not currently in the named selection. • Convert To: Changes the geometric Entity Type selected in the previous row. The change is in either direction with respect to the topology (for example, vertices can be converted “up” to edges, or bodies can be converted “down” to faces). When going up in dimensionality, the higher level topology is selected if you select any of the lower level topology (for example, a face will be selected if any of its edges are selected). You can also convert from a geometry selection (bodies, edges, faces, vertices) to mesh nodes. The nodes that exist on the geometry (that is, the nodes on a face/edge/vertex or nodes on and within a body) will be selected. In addition, node-based Named Selections can be converted to elements and element-based Named Selections can be converted to nodes using this action.

Note The conversion from geometry selection to mesh nodes is analogous to using Mechanical APDL commands NSLK, NSLL, NSLA, and NSLV. The conversion from elements to mesh nodes uses NSLE and conversion from mesh nodes to elements uses ESLN.

Entity Type column: • Body • Face • Edge • Vertex • Mesh Node • Mesh Element Criterion column: • Size — available when Entity Type = Body, Face, or Edge. • Type — available when Entity Type = Body, Face, Edge, or Mesh Node, or Mesh Element. • Location X Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Specifying Geometry • Location Y • Location Z • Face Connections — available when Entity Type = Edge. • Radius — available when Entity Type = Face or Edge. Applies to faces that are cylindrical and edges that are circular. • Distance

Note For the Distance Criterion, the calculation of the centroid is not supported for Line Bodies.

• Named Selection • Material — available when Entity Type = Body. • Node ID — Available when Entity Type is Mesh Node. • For Entity Type = Mesh Element. – Element ID – Volume – Area – Element Quality – Aspect Ratio – Jacobian Ratio – Warping Factor – Parallel Deviation – Skewness – Orthogonal Quality You may wish to refer to the Mesh Metric section of the Meshing User’s Guide for more information about these Criterion options. Operator column: • Equal • Not Equal • Less Than • Less Than or Equal 436

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Named Selections • Greater Than • Greater Than or Equal • Range includes Lower Bound and Upper Bound numerical values that you enter. • Smallest • Largest Units column: read-only display of the current units for Criterion = Size or Location X, Y, or Z. Value column: • For Criterion = Size, enter positive numerical value. • For Criterion = Location X, Y, or Z, enter numerical value.

Note Selection location is at the centroids of edges, faces, bodies, and elements.

• For Entity Type = Body and Criterion = Type: – Solid – Surface – Line • For Entity Type = Face and Criterion = Type: – Plane – Cylinder – Cone – Torus – Sphere – Spline – Faceted • For Entity Type = Edge Criterion = Type: – Line – Circle – Spline – Faceted Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Specifying Geometry • For Entity Type = Mesh Node and Criterion = Type: – Corner – Midside • For Entity Type = Mesh Element and Criterion = Type: – Tet10 – Tet4 – Hex20 – Hex8 – Wed15 – Wed6 – Pyr13 – Pyr5 – Tri6 – Tri3 – Quad8 – Quad4 – High Order Beam – Low Order Beam • For Entity Type = Edge and Criterion = Face Connections, enter the number of shared edge connections. For example, enter Value = 0 for edges not shared by any faces, enter Value = 1 for edges shared by one face, and so on. • For Criterion = Named Selection, you can include a previously-defined named selection from the Value field. Only the named selections that appear in the tree before the current named selection are listed in Value. For example, if you have defined two named selections prior to the current named selection and two named selections after, only the two prior to the current named selection are shown under Value. When you define a named selection to include an existing named selection, you should use the Generate Named Selections RMB option from the Named Selections folder object in the tree to make sure that all of the latest changes to all named selections are captured. Named selections are generated in the order that they are listed in the tree and as a result, when you click the Generate button in the Worksheet, only the associated named selection is updated. Any other Named Selection that may have been changed is not updated. The Generate Named Selections feature better ensures that all child objects of the Named Selection folder are updated. For Criterion = Material, select the desired material from the drop-down list. See the Material Assignment topic for more information.

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Named Selections • For Criterion = Distance, enter a positive numerical value from the origin of the selected coordinate system. Lower Bound column: enter numerical value. Upper Bound column: enter numerical value. Coordinate System column: • Global Coordinate System • Any defined local coordinate systems

Adjusting Tolerance Settings for Named Selections by Worksheet Criteria Tolerance settings are used when the Operator criterion is defined as an «equal» comparison. Tolerances are not used when doing greater than or less than operations. Tolerance values apply to the entire worksheet. If you wish to adjust the tolerance settings for worksheet criteria, use the Tolerance settings in the chosen Named Selection’s Details view. By default, the Zero Tolerance property is set to 1.e-008 and the Relative Tolerance value is 1.e-003. As a result of the significant digit display, the value used for calculations and the display value may appear to be different. The Zero Tolerance property’s value is past the number of significant digits that Mechanical shows by default. The application’s default setting for significant digits is 5 (the range is 3 to 10). This setting affects only the numbers that are displayed, any calculation or comparison uses the actual values when processing. In addition, it is important to note that most values (including selection values seen in the status bar and the Selection Information window) in Mechanical display in a significant digit format. See the Appearance option in the Setting ANSYS Workbench section of the Help for information about changing default display settings. Setting the tolerance values manually can also be useful in meshing, when small variances are present in node locations and the default relative tolerance of .001 (.1%) can be either too small (not enough nodes selected) or too big (too many nodes selected). 1.

In the Details view, set Tolerance Type to Manual.

2.

Specify either a Zero Tolerance or a Relative Tolerance. Tolerance values are dimensionless. Relative tolerance is a multiplying factor applied to the specified worksheet value. For example, if you want a tolerance of 1%, enter .01 in the Relative Tolerance field. All comparisons are done in the CAD unit system.

Criteria Named Selections Based on Selected Geometry You may have the need to create Named Selections that use criteria but are based on pre-selected geometry. For example, the criteria may be to pick every face that shares both the same X location and the same size as the selected face. For these situations, you can first select the geometry, then, instead of configuring the Worksheet directly, you can use the following more direct procedure to define the criteria for the Named Selection. 1. After selecting geometry, choose Create Named Selection (left button on the Named Selection Toolbar (p. 69) or right-click context menu choice). 2. In the Selection Name dialog box that appears, you can enter a name for the particular Named Selection or accept Selection as the default name. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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a. To define the Named Selection based only on the selected geometry without defining any criteria, choose Apply selected geometry and click OK. b. To define the Named Selection based on criteria related to the selected geometry: i.

Choose Apply geometry items of same, then check one or more applicable criteria items and click OK. These items are sensitive to the selected geometry (for example, if a vertex is selected, there are no Size or Type entries).

ii. Choosing the above option activates the Apply to Corresponding Mesh Nodes field. Checking this field automatically adds a Covert To (see Help above) row to the Worksheet that coverts the geometry to mesh nodes.

Note This option requires that you generate the mesh.

Once the above steps are completed, the Named Selection is automatically generated and listed as a Selection object (default name) under the Named Selections folder. If you specified criteria and highlight the Selection object, the associated Worksheet is populated automatically with the information you entered in the Selection Name dialog box. To illustrate the steps presented above: 1. Select a face. 2. Choose Create Named Selection. 3. Choose Apply geometry items of same. 4. Check Size and Location X, then choose OK. 440

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Named Selections The Worksheet associated with the new Named Selection would be populated automatically with the following information: First Row • Action = Add • Entity Type = Face • Criterion = Size • Operator = Equal Second Row • Action = Filter • Entity Type = Face • Criterion = Location X • Operator = Equal

Promoting Scoped Objects to a Named Selection In addition to creating Named Selections, you can also use the promotion feature to create a named selection from an existing object that is scoped to geometry or mesh. Objects that support the promotion feature include: • Remote Points • Contact Regions • Springs • Joints • Boundary Conditions • Results and Custom Results All of these objects have one thing in common when using the promotion feature, they are first scoped to geometry or mesh. This is the specification basis for the promoted Named Selections. Each promoted Named Selection inherits the geometry or mesh scoping of the object used. In addition, the Scoping Method property automatically updates to Named Selection and specifies the corresponding scoping.

Note • This action changes the scoping of the corresponding object and may, as a result, cause upto-date states to become obsolete. For example, promoting a Fixed Support from a completed solution would cause the solution to become obsolete and require it to be re-solved. • In order to promote objects scoped to the mesh, you need to make sure that the Show Mesh feature (on the Graphics Options Toolbar) is active.

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Specifying Geometry By highlighting one of the above objects and right-clicking, such as the Contact Region example illustrated below, the context menu provides the option Promote to Named Selection. Once selected, the feature automatically adds a Named Selections folder to the tree that includes two new Named Selections based on the existing name of the contact object as well as its geometry scoping, Contact and Target. You can promote an object to a Named Selection only once. Deleting the corresponding Named Selection makes the option available again. However, deleting the Named Selection also invalidates the corresponding source object, such as the Contact Region shown in the example below. As a result, you must re-scope the source object to geometry or mesh for the feature to be available. A Contact Region example is slightly different in that it has Contact and Target scoping and that this feature creates two Named Selections. Springs and Joints also create two Named Selections if they are defined as BodyBody. The other object types create one Named Selection. Also note that result objects can be promoted before or after the solution process.

Displaying Named Selections You can use geometry entity Named Selections to inspect only a portion of the total mesh. Although this feature is available regardless of mesh size, it is most beneficial when working with a large mesh (greater than 5 — 10 million nodes). After you have designated a Named Selection group, you can use any of the following features to assist you in this task:

Showing the Mesh By setting the Plot Elements Attached to Named Selections option in the Annotation Preferences, you can view the elements for all items in the Named Selection group. For node-based Named Selections,

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Named Selections this option shows the full elements, while for face or body Named Selections, this option shows just the element faces.

Note This option does not affect Line Bodies, and you must have the Show Mesh button toggled off to view the elements in the Named Selection. An example is shown below of a node-based Named Selection.

Showing Annotations As illustrated below, selecting the Named Selection folder displays all of the user-defined Named Selection annotations in the Graphics pane. This display characteristic can be turned On or Off using the Show Annotation category in the Named Selections Details view. Selecting an individual Named Selection displays the annotation specific to that Named Selection in the Graphics pane.

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Specifying Geometry You can also toggle the visibility of mesh node annotations and numbers in the annotation preferences. For more information, see Specifying Annotation Preferences (p. 119).

Displaying Individual Named Selections in Different Colors By default, Named Selections are shown in red. You can use the Random Colors button in the Graphics Options toolbar to display each named selection with a random color at each redraw.

Setting Visibility By setting the Visible object property in the Details view of an individual Named Selection object to No, the Named Selection can be made invisible, meaning it will not be drawn and, more importantly, not taken into consideration for picking or selection. This should allow easier inspection inside complicated models having many layers of faces where the inside faces are hardly accessible from the outside. You can define Named Selections and make them invisible as you progress from outside to inside, similar to removing multiple shells around a core. The example shown below displays the Named Selection 3 Faces with the Visible property set to No.

Displaying an Enhanced View of Meshed Items Display your model in Wireframe mode by selecting the Wireframe button on the Graphics Options Toolbar or by selecting View> Wireframe. Then, open the Annotation Preferences dialog box by selecting 444

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Named Selections View>Annotation Preferences. Check the Plot Elements Attached to Named Selections option. This feature displays the meshed entities of your Named Selection only, as illustrated below.

Notes • The Visible object property is the same as the Hide Face(s) option in the right mouse button context menu. These options will hide only the specified Named Selection. This behavior differs from that of the Hide Bodies in Group and Suppress Bodies in Group options, which hide or suppress the full body containing a given Named Selection. • When a Named Selection’s Visible setting is set to No: – Only the faces from that Named Selection are not drawn; the edges are always drawn. – The Named Selection will not appear in any drawing of the geometry (regardless of which object is selected in the tree). Unless… – The Named Selection is displayed as meshed, it displays the mesh, but only if you have the Named Selection object or the Named Selections folder object is selected in the tree. This behavior is the same as the behavior of the red annotation in the Geometry window for Named Selections (that is, the annotation appears only when the current selected object is the specific Named Selection object or the Named Selections folder object). • After at least one Named Selection is hidden, normally you can see the inside of a body, so displaying both sides of each face is enabled (otherwise displaying just the exterior side of each face is enough). But if a selection is made, the selected face is always displayed according to the option in Tools> Options> Mechanical> Graphics> Single Side (can be one side or both sides). • If the Wireframe display option is used and Show Mesh is Yes, any face selected is displayed according to the option in Tools> Options> Mechanical> Graphics> Single Side (can be one side or both sides).

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Using Named Selections This section describes the features for managing and employing Named Selections, and includes: Using Named Selections via the Toolbar Scoping Analysis Objects to Named Selections Including Named Selections in Program Controlled Inflation Importing Named Selections Exporting Named Selections

Using Named Selections via the Toolbar The Named Selection toolbar allows you to select and modify user-defined named selections. You can turn it on or off by selecting View> Toolbars> Named Selections. To use a Named Selection toolbar: 1. Select a named selection from the drop-down list of available Named Selections. This list matches the named selections contained beneath the Named Selections folder object. 2. Choose from the following options provided by toolbar: Control

Description

Selection drop-down menu

Controls selection options on items that are part of the group whose name appears in the Named Selection display. Available options are:

(or in context menu from right clicking the mouse button on individual Named Selection object)

• Select Items in Group: selects only those items in the named group. • Add to Current Selection: Picks the scoped items defined by the Named Selection that you have highlighted and adds those items to the item or items that you have selected in the geometry window. This option is grayed out if the selections do not correspond, such as selecting trying to add a faces to vertices. • Remove from Current Selection: Removes the selection of items in the named group from other items that are already selected. Selected items that are not part of the group remain selected. This option is grayed out if the entity in the Named Selection does not match the entity of the other selected items. • Create Nodal Named Selection: Automatically converts the geometry specified by the Named Selection to mesh nodes. A corresponding Covert To row is added to the Worksheet

Note Choosing any of these options affects only the current selections in the Geometry view, These options have no effect on what is included in the Named Selection itself. Visibility dropdown menu

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Controls display options on bodies that are part of the group whose name appears in the Named Selection display. Available options are: Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

Named Selections Control

Description • Hide Bodies in Group: Turns off display of bodies in the named group (toggles with next item). Other bodies that are not part of the group are unaffected. • Show Bodies in Group: Turns on display of bodies in the named group (toggles with previous item). Other bodies that are not part of the group are unaffected. • Show Only Bodies in Group: Displays only items in the named group. Other items that are not part of the group are not displayed. You can also hide or show bodies associated with a Named Selection by right-clicking the Named Selections object and choosing Hide Bodies in Group or Show Bodies in Group from the context menu. You can hide only the Named Selection by right-clicking on the Named Selections object and choosing Hide Face(s).

Suppression drop-down menu

Controls options on items that affect if bodies of the group whose name appears in the Named Selection display are to be suppressed, meaning that, not only are they not displayed, but they are also removed from any treatment such as loading or solution. Available options are: • Suppress Bodies in Group: Suppresses bodies in the named group (toggles with next item). Other bodies that are not part of the group are unaffected. • Unsuppress Bodies in Group: Unsuppresses bodies in the named group (toggles with previous item). Other bodies that are not part of the group are unaffected. • Unsuppress Only Bodies in Group: Unsuppresses only bodies in the named group. Other bodies that are not part of the group are suppressed. You can also suppress or unsuppress bodies associated with a Named Selection by right-clicking the particular Named Selections object and choosing Suppress Bodies In Group or Unsuppress Bodies In Group from the context menu. The Suppress Bodies In Group and Unsuppress Bodies In Group options are also available if you select multiple Named Selection items under a Named Selections object. The options will not be available if your multiple selection involves invalid conditions (for example, if you want to suppress multiple items you have selected and one is already suppressed, the Suppress Bodies In Group option will not be available from the context menu.

The status bar shows the selected group area only when the areas are selected. The group listed in the toolbar and in the Details View (p. 11) provides statistics that can be altered.

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Scoping Analysis Objects to Named Selections Many objects can be scoped to Named Selections. Some examples are contact regions, mesh controls, loads, supports, and results. To scope an object to a Named Selection: 1. Insert or select the object in the tree. 2. Under the Details view, in the Scoping Method drop-down menu, choose Named Selection. 3. In the Named Selection drop-down menu, choose the particular name. Notes on scoping items to a Named Selection: • Only Named Selections valid for the given analysis object are displayed in the Named Selection dropdown menu. If there are no valid Named Selections, the drop-down menu is empty. • No two Named Selections branches can have the same name. It is recommended that you use unique and intuitive names for the Named Selections. • Named Selection modifications update scoped objects accordingly. • Deleting a Named Selection causes the scoped object to become underdefined. • If all the components in a Named Selection cannot be applied to the item, the Named Selection is not valid for that object. This includes components in the Named Selection that may be suppressed. For example, in the case of a bolt pretension load scoped to cylindrical faces, only 1 cylinder can be selected for its geometry. If you have a Named Selection with two cylinders, one of which is suppressed, that particular Named Selection is still not valid for the bolt pretension load.

Including Named Selections in Program Controlled Inflation By default, faces in Named Selections are not selected to be inflation boundaries when the Use Automatic Inflation control is set to Program Controlled. However, you can select specific Named Selections to be included in Program Controlled inflation. To do so: 1. Create a Named Selection. 2. Click the desired Named Selection in the tree and then in the Details view, set the Program Controlled Inflation option to Include. 3. In the mesh controls, set the Use Automatic Inflation control to Program Controlled. As a result, the Named Selection you chose in step 2 is selected to be an inflation boundary, along with any other faces that would have been selected by default.

Importing Named Selections You can import geometric entity Named Selections that you defined in a CAD system or in DesignModeler. A practical use in this case is if you want the entities of the Named Selection group to be selected for the application of loads or boundary conditions. To import a Named Selection from a CAD system or from DesignModeler:

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Named Selections 1. In the Geometry preferences, located in the Workbench Properties of the Geometry cell in the Project Schematic, check Named Selections and complete the Named Selection Key; or, in the Geometry Details view under Preferences, set Named Selection Processing to Yes and complete the Named Selection Prefixes field (refer to these entries under Geometry Preferences for more details). 2. A Named Selections branch object is added to the Mechanical application tree. In the Named Selection Toolbar, the name of the selection appears as a selectable item in the Named Selection display (located to the right of the Create Selection Group button), and as an annotation on the graphic items that make up the group.

Exporting Named Selections You can export the Named Selection that you create using the Graphics Viewer and Worksheet, and save the contents to a text or Microsoft Excel file. To export the Named Selection object: 1. Right-click on the desired Named Selection object and select Export. 2. Name and save the file. The text or Microsoft Excel file you export includes a list of generated node ids, by default. You can also include the location information of the generated node ids in the exported file. To include node id location information in the exported file: 1.

Click Tools > Options

2.

Expand the Mechanical folder, and then click Export

3.

Under Export, click the Include Node Location drop-down list, and then select Yes.

Note • The Named Selection Export feature is available only for node-based and element-based Named Selection objects. • Node Numbers are always shown in the exported text or Microsoft Excel file irrespective of setting for Include Node Numbers in Tools > Options > Export.

Displaying Interior Mesh Faces There are special instances when a Named Selection is an interior “back-facing face”. This is a unique case that occurs when the external faces of the geometry are hidden allowing interior faces to become visible. To display the faces of the mesh, the Named Selections object must be highlighted in the tree and the Plot Elements Attached to Named Selections option in the Annotation Preferences must be selected. Then, to correct the display, use the Draw Face Mode options available under View>Graphics Options, which include:

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Specifying Geometry • Auto Face Draw (default) — turning back-face culling on or off is program controlled. Using Section Planes is an example of when the application would turn this feature off. • Draw Front Faces — face culling is forced to stay on. Back-facing faces will not be drawn in any case, even if using Section Planes. • Draw Both Faces — back-face culling is turned off. Both front-facing and back-facing faces are drawn. Incorrect Display

Correct Display using Draw Face Mode

Converting Named Selection Groups to Mechanical APDL Application Components When you write a Mechanical APDL application input file that includes a Named Selection group, the group is transferred to the Mechanical APDL application as a component provided the name contains only standard English letters, numbers, and underscores. The Named Selection will be available in the input file as a Mechanical APDL component for use in a Commands object. Geometry scoping to bodies will result in an element-based component. All other scoping types will result in a nodal component. The following actions occur automatically to the group name in the Mechanical application to form the resulting component name in the Mechanical APDL application: • A name exceeding 32 characters is truncated. • A name that begins with a number is renamed to include “C_” before the number. • Spaces between characters in a name are replaced with underscores. Example: The Named Selection group in the Mechanical application called 1 Edge appears as component C_1_Edge in the Mechanical APDL application input file.

Note Named selections starting with ALL, STAT, or DEFA will not be sent to the Mechanical APDL application.

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Mesh Numbering

Mesh Numbering The Mesh Numbering feature allows you to renumber the node and element numbers of a generated meshed model consisting of flexible parts. The feature is useful when exchanging or assembling models and could isolate the impact of using special elements such as superelements. The Mesh Numbering feature is available for all analysis systems except Rigid Dynamics analyses. Because this feature changes the numbering of the model’s nodes, all node-based scoping is lost when mesh numbering is performed, either in a suppressed or unsuppressed state. If this situation is encountered, a warning message allows you to stop the numbering operation before the node-based scoping is removed. You can prevent the loss of any node-based scoping by using criteria-based Named Selections, or by scoping an object to nodes after mesh renumbering has taken place. Criteria-based Named Selections scoped to nodes are supported in combination with the Mesh Numbering object as long as you have the Generate on Remesh property set to Yes. To activate Node Number Compression: By default node numbers will not be compressed to eliminate gaps in the numbering that can occur from events such as remeshing or suppression of meshed parts. This allows maximum reuse of mesh based Named Selections but can result in node numbers that are higher than required. Node number compression can be turned on by setting Compress Numbers to Yes. If compression is turned on, the compression will occur before any other numbering controls are applied. To activate Mesh Numbering: 1. Insert a Mesh Numbering folder by highlighting the Model folder, then: a. Selecting the Mesh Numbering toolbar button. Or… b. Right-clicking on the Model folder and choosing Insert> Mesh Numbering. Or… c. Right-clicking in the Geometry window and choosing Insert> Mesh Numbering. 2. In the Details view, set Node Offset or Element Offset values for the entire assembly, as needed. For example, specifying a Node Offset of 2 means that the node numbering for the assembly will start at 2.

Note The Node Offset value cannot exceed a value that results in a node number having a magnitude greater than one (1) billion. Mesh numbering of this magnitude requires considerable processing power.

3. Insert a Numbering Control object by highlighting the Mesh Numbering folder (or other Numbering Control object), then:

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Specifying Geometry a. Selecting the Numbering Control toolbar button. Or… b. Right-clicking on the Mesh Numbering folder (or other Numbering Control object) and choosing Insert> Numbering Control. Or… c. Right-clicking in the Geometry window and choosing Insert> Numbering Control. 4. Specify a part, a vertex, or a Remote Point in the model whose node or element numbers in the corresponding mesh are to be renumbered. a. To specify a part: i.

Select the part.

ii. In the Details view, set Scoping Method to Geometry Selection, click the Geometry field and click Apply. iii. Enter numbers in the Begin Node Number and/or Begin Element Number fields. Also, if needed, change the End Node Number and End Element Number from their default values. b. To specify a vertex: i.

Select the vertex.

ii. In the Details view, set Scoping Method to Geometry Selection, click the Geometry field and click Apply. iii. Enter the Node Number. c. To specify a Remote Point that has already been defined: i.

In the Details view, set Scoping Method to Remote Point, click the Remote Points field and choose the specific Remote Point in the drop down menu.

ii. Enter the Node Number. 5. Right-click the Mesh Numbering folder, or a Numbering Control object, and choose Renumber Mesh. If the model is not meshed, it will first generate a mesh and then perform mesh numbering. The nodes and elements are numbered based on the values that you specified.

Note During the mesh numbering process, the user interface enters a waiting state, meaning you cannot perform any actions such as clicking objects in the tree. In addition, you cannot cancel the process once it is started and must wait for its completion. However, a progress dialog box appears to report status during the operation.

Mesh Numbering Characteristics • The Mesh Numbering feature is available in both the Mechanical application and the Meshing applications. 452

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Path (Construction Geometry) • The Node Offset value cannot exceed a value that results in a node number having a magnitude greater than one (1) billion. Mesh numbering of this magnitude requires considerable processing power. • Geometry selection is part-based, not body-based. • Selecting Update at the Model level in the Project Schematic updates the mesh renumbering. • The Solve is aborted if mesh renumbering fails. • Whenever a control is changed, added, or removed, the mesh renumbering states are changed for all controls where mesh numbering is needed. • When exporting mesh information to Fluent, Polyflow, CGNS, or ICEM CFD format, the last status is retained at the time of export. If renumbering has been performed, the mesh is exported with nodes and elements renumbered. If not, the original mesh numbering is used. • Mesh renumbering of a Point Mass is not supported. • The Convergence object is not supported with Mesh Numbering folder.

Note Be cautious when deleting the Mesh Numbering folder. Deleting this folder leaves the mesh in the numbered state that you specified. There is no way to know that the existing mesh has been renumbered.

Mesh Numbering Suppression Characteristics For Mesh Numbering, the suppression feature operates differently. Rather than excluding the object when the Mesh Numbering object is suppressed, the mesh numbering instead returns to the original numbering. That is, it resets and updates the input deck’s contents. This change can affect analysis operations. As a result, restrictions have been implemented, and Mechanical no longer supports suppression of the Mesh Numbering object. For legacy (v14.5 and earlier) files, an error is generated in the Message Window if suppressed Mesh Numbering objects are present. You can continue your analysis by manually changing the Suppressed property setting to No, but the change is then permanent; the application will not allow you to return this setting to Yes.

Path (Construction Geometry) A path is categorized as a form of construction geometry and is represented as a spatial curve to which you can scope path results. The results are evaluated at discrete points along this curve. A path can be defined in two principal ways: • By start point and end point. These points can be specified directly or can be calculated from the entry and exit point (intersections) of the positive X-axis of a coordinate system through a mesh. The path may be a straight line segment or a curve depending on the type of coordinate system (Cartesian or Cylindrical). You can control

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Specifying Geometry the discretization by specifying the number of sampling points, and these will be evenly distributed along the path up to a limit of 200.

Note Paths defined in this manner will only be mapped onto solid or surface bodies. If you wish to apply a path to a line body you must define the path by an edge (as described below).

• By an edge. The discretization will include all nodes in the mesh underlying the edge. Multiple edges may be used but they must be continuous. For each result scoped to a Path, the Graph Controls category provides an option to display the result in the Graph on X-axis, as a function of Time or with S, the length of the path. Note that Path results have the following restrictions: They are calculated on solids and surfaces but not on lines. They can be collected into charts as long as all of the other objects selected for the chart have the same X-axis (Time or S). You can define a path in the geometry by specifying two points, an edge, or an axis. Before you define a path, you must first add the Path object from the Construction Geometry context toolbar. You can then define the path using any of the three methods presented below.

Defining a Path using Two Points Using this method you define the path by specifying two points in any of the following ways: To define the path using the Coordinate toolbar button: 1. In the Details view, select Two Points in the Path Type list. 2. Under Start, choose Click to Change in the Location row . 3. Depress the Coordinate toolbar button. As you move the cursor across the model, the coordinates display and update as you reposition the cursor.

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Path (Construction Geometry) 4. Click at the desired start location for the path. A small cross hair appears at this location. You can click again to change the cross hair location. 5. Click Apply. A “1” symbol displays at the start location. Also, the coordinates of the point display in the Details view. You can change the location by repositioning the cursor, clicking at the new location, and then clicking Click to Change and Apply, or by editing the coordinates in the Details view. 6. Repeat steps 2 through 5 to define the end point of the path under End in the Details view. A “2” symbol displays at the end location. 7. Enter the Number of Sampling Points. To define the path using coordinates: 1.

In the Details view, select Two Points in the Path Type list.

2.

Under Start, enter the X, Y, and Z coordinates for the starting point of the path.

3.

Under End, enter the X, Y, and Z coordinates for the ending point of the path.

4.

Enter the Number of Sampling Points.

To define a Path using vertices, edges, faces, or nodes: 1.

In the Details view, select Two Points in the Path Type list.

2.

Select one or more vertices or nodes, a single edge, or a face where you want to start the path, and then click Apply under Start, Location. An average location is calculated for multiple vertex or node selections.

3.

Select the vertices, nodes, face, or the edge where you want to end the path, and then click Apply under End, Location.

4.

Enter the Number of Sampling Points.

Note The start and end points need not both be specified using the same procedure of the three presented above. For example, if you specify the start point using the Coordinate toolbar button, you can specify the end point by entering coordinates or by using a vertex, edge, or face. Any combination of the three procedures can be used to specify the points.

Snap to Mesh Nodes When solving linearized stresses, the path you define by two points must be contained within the finite element mesh to avoid an error. Because the two points can be derived from the tessellation of the geometric model, the points may be contained within the geometry but may not be contained within the mesh. This is especially true for curved geometry faces. After defining the two points using the Coordinate toolbar button method (see above), you can ensure that the path is contained within the mesh by using the Snap to mesh nodes feature. To use the feature, set Show Mesh to Yes in the Details view of the Construction Geometry object in order to see the location of the nodes in the mesh. Then, right click on the Path object and select Snap to mesh nodes from the context menu. This action alters the path, as necessary, such that both the start point and end point of the path snap to the closest node in the mesh. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Specifying Geometry The Snap to mesh nodes feature avoids the error and allows the solve to continue provided the path you define does not traverse through any discontinuities in the model, such as a hole. For these cases, even though the Snap to mesh nodes feature alters the path endpoints to coincide with the nearest nodes in the mesh, the linearized stress result still fails because the path is defined through the discontinuity. The following pictures illustrate this feature. Attempt to solve for linearized stress. Path defined within geometric model:

Corresponding mesh used for geometric model, obtained by setting Show Mesh to Yes:

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Path (Construction Geometry)

Path contained within mesh after choosing Snap to mesh nodes. Solution completes:

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Note If the model is re-meshed after choosing Snap to mesh nodes, the feature is not automatically applied to the newly meshed model. You must choose Snap to mesh nodes again to alter the path start and end points to the new mesh.

Defining a Path using an Edge This method helps you define a path by selecting an edge. To define a path: 1.

In the Details view, select Edge in the Path Type list.

2.

Select a geometry edge, and then click Apply under Scope.

Defining a Path from Results Scoped to Edges In order to help better quantify the variation of a result along a set of edges, path results are available. For a result that is scoped to an edge or multiple contiguous edges, you can convert the scoping to the equivalent Path, by: 1.

Selecting the result object that is scoped to an edge or contiguous edges.

2.

Display the context menu by right-clicking the mouse, and the select Convert To Path Result.

A Path is automatically created and a corresponding Path object is displayed in the tree with a Path Type of Edge.

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Surface (Construction Geometry)

Defining a Path using X-axis Intersection Depending on the coordinate system you select, Workbench creates a Path from the coordinate system origin to the point where the X-axis of the selected coordinate system intersects a geometry boundary. Workbench computes intersections of the axis with the mesh and displays more precise locations for path endpoints for the path results. The endpoints for the path are not modified, and remain as the intersections with the geometry. The first compact segment of the path inside a single body is included in the path definition. 1.

In the Details view, select X Axis Intersection in the Path Type list.

2.

Select the coordinate system you want to use to define the x-axis.

3.

Enter the Number of Sampling Points.

Defining a Path from Probe Labels While reviewing results, you can define a path automatically from two probe labels. To define the path: 1.

Create two probe annotations by choosing the Probe button from the Result Context Toolbar (p. 59).

2.

Choose the Label button from the Graphics Toolbar (p. 50) and select the two probe annotations. (Hold the Ctrl key to select both probe annotations.)

3.

Right-click in the Geometry window and choose Create Path From Probe Labels from the context menu.

4.

A path is automatically created between the probe annotations. A corresponding Path object is displayed in the tree with a Path Type of Two Points.

Exporting Path Data You can export coordinate data for a defined path by clicking the right mouse button on a Path object and choosing Export from the context menu.

Surface (Construction Geometry) A surface is categorized as a form of construction geometry and is represented as a section plane to which you can scope surface results or reaction probes. To define a surface: 1. Highlight the Model object and click the Construction Geometry toolbar button to produce a Construction Geometry object. 2. Highlight the Construction Geometry object and click the Surface toolbar button to produce a Surface object. 3. Define a coordinate system whose X-Y plane will be used as a cutting plane, as follows: a. Create a local coordinate system.

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Specifying Geometry b. Define the origin of the local coordinate system.

Note With respect to the facets of the surface: • For a Cartesian coordinate system, the surface is the intersection of the model with the X-Y plane of the coordinate system. • For a cylindrical coordinate system, the surface is the intersection of the model with the cylinder whose axis is the Z axis of the coordinate system. In this case, you must specify the radius in the Details view of the Surface object.

Tip For an existing coordinate system, you can define a Surface Construction Geometry object by selecting the desired coordinate system object, right-clicking, and selecting Create Construction Surface. This feature allows you to define the coordinate system first.

Remote Point You use a Remote Point as a scoping mechanism for remote boundary conditions. Remote points are a way of abstracting a connection to a solid model, be it a vertex, edge, face, body, or node, to a point in space (specified by Location). The solver uses multipoint constraint (MPC) equations to make these connections. Remote Points are akin to the various remote loads available in the Mechanical application. Remote boundary conditions create remote points in space behind the scenes, or, internally, whereas the Remote Point objects define a specific point in space only. As a result, the external Remote Point can be associated to a portion of geometry that can have multiple boundary conditions scoped to it. This single remote association avoids overconstraint conditions that can occur when multiple remote loads are scoped to the same geometry. The overconstraint occurs because multiple underlying contact elements are used for the individual remote loads when applied as usual to the geometry. When the multiple remote loads are applied to a single remote point, scoped to the geometry, the possibility of overconstraint is greatly reduced. Remote Points are a powerful tool for working with and controlling the Degrees of Freedom (DOF) of a body. Remote Points provide a property, DOF Selection, which gives you a finer control over the active DOF’s used to connect the Remote Point location to the body. Furthermore, Remote Points can be can be used independently, without being scoped to a boundary condition. Remote Point create MPC equations and therefore can be used to model phenomena, such as coupling a set of nodes so that they have the same DOF solution. Another capability of Remote Points is that they are also a scoping mechanism for the Constraint Equation object. The equation relates the degrees of freedom (DOF) of one or more remote points A Remote Point or multiple remote points work in tandem with the boundary conditions listed below. • Point Mass

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Remote Point • Thermal Point Mass • Joints • Spring • Bearing • Beam Connection • Remote Displacement • Remote Force • Moment These objects acquire data from remote points and eliminate the need to define the objects individually. You can scope one or more of the above objects to a defined Remote Point. This provides a central object to which you can make updates that will affect the scoping of multiple objects.

Note Following are important points to keep in mind when using Remote Points: • A Remote Point can reference only one Remote Force and one Moment. If you scope a Remote Point to multiple remote forces or moments, duplicate specifications are ignored and a warning message is generated. • A Remote Point with Deformable behavior should not be used on surfaces that are modeled with symmetry boundary conditions. The internally generated weight factors only account for the modeled geometry. Therefore, remote points with deformable behavior should only be used on the “full” geometry.

For additional MAPDL specific information, see the Multipoint Constraints and Assemblies section as well as KEYOPT(2) in the Mechanical APDL Contact Technology Guide. The following sections describe how to create and define a Remote Point as well as the characteristics and limitations associated with this scoping tool. Specify a Remote Point Geometry Behaviors and Support Specifications Remote Point Features

Specify a Remote Point To insert a Remote Point, select the Model object in the tree and then either select the Remote Point button from the Model Context Toolbar or right-click the mouse and select Insert>Remote Point. You then scope the Remote Point to a face or faces, edge or edges, vertex or vertices, or a node or nodes.

Note To select a node or nodes, you first need to generate the mesh.

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Specifying Geometry MAPDL Reference When you scope your Remote Point to a single node or multiple nodes, a point-to-surface contact algorithm is used (using contact element CONTA175). This process can produce slightly different result at the area of application compared to face scoping of the same topology. Geometry scoping to 3D faces and 2D edges uses a constant traction contact application (contact elements CONTA171 through CONTA174).

Note Be very careful when you scope remote points to nodes if the nodes are collinear. A rigid Formulation avoids issues when you scope to Surface or Line bodies. However for solids, you should not scope collinear nodes for any Formulation. Remote Point definable properties are illustrated and described below: • Scoping Method: Geometry (default) or Named Selection. • Geometry or Named Selection (geometry or node-based) selection. • Coordinate System: the Coordinate System based on the original location of the remote point. This property does not change if you modify the remote point’s position with the Location property. • X Coordinate: the distance from the coordinate system origin on the x axis. • Y Coordinate: the distance from the coordinate system origin on the y axis. • Z Coordinate: the distance from the coordinate system origin on the z axis. • Location: the location in space of the remote point. This property allows you to manually modify the remote point’s original position. Changing the Location does not establish a new coordinate system (that is not reflected by the above Coordinate System property) and replots the x, y, and z coordinate locations. • Behavior. This property defines the contact formulations. Options include Deformable, Rigid, or Coupled. • Pinball Region: value entry. • DOF Selection: Program Controlled (default) or set as Manual. This offers an opportunity for better control of which DOF’s will activate for corresponding constraint equations.

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Remote Point The Details view of each of the above objects contains a Scoping Method setting that can be set to Remote Point, once a Remote Point is defined, as illustrated below for the details of a Remote Force. Once you scope the object with a Remote Point and define which remote point (Remote Point Front Edge or Remote Point Rear Face) if more than one exists, all of the inputs from that remote point become read-only for the object and use the remote point’s data. Scope to Remote Point

Choose Appropriate Remote Point

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Specifying Geometry

As illustrated in the above example, after you have scoped the Remote Force to a Remote Point, additional data may be required, such as Magnitude.

Geometry Behaviors and Support Specifications The Behavior option dictates the behavior of the attached geometry. You can specify the Behavior of the scoped geometry for a remote boundary condition in the Details view as either Rigid, Deformable, or Coupled. • Deformable — The geometry is free to deform. This is a general purpose option used when applying boundary conditions such as a force or mass through ”abstract” entities not explicitly represented as geometry inside Mechanical. This formulation is similar to the MAPDL constraint defined by the RBE3 command. • Rigid — The geometry will not deform (maintains the initial shape). This option is useful when the «abstracted» object significantly stiffens the model at the attachment point. Note that thermal expansion effects cause artificially high stresses because the geometry cannot deform where the load is applied. This formulation is similar to the MAPDL constraint defined by the CERIG command. • Coupled — The geometry has the same DOF solution on its underlying nodes as the remote point location. This is useful when you want a portion of geometry to share the same DOF solution (such as UX) that may or may not be known. For example, to constrain a surface to have the same displacement in the X direction, simply create a remote point, set the formulation to Coupled, and activate the X DOF. Because the DOF is known, you can specify an additional Remote Displacement. This formulation is similar to the MAPDL constraint defined by the CP command. Examples of these behaviors are illustrated below. Rigid Behavior

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Remote Point

Deformable Behavior

Coupled Behavior

Support Specifications Note the following when using the Remote Point feature. • MAPDL solver logic is based on MPC-based contact. See the Surface-Based Constraints section of the Mechanical APDL Contact Technology Guide for more information. A Remote Point scoped to a vertex or vertices in a 2D or 3D solid does not use the contact MPC, it creates embedded beams to connect the vertex to the Remote Point. • The MPC equations are generated from the definition of a Remote Point are based on the underlying element shape functions. In a large deflection analysis, element shapes are reformed each substep. As a result, MPC equations are superior to the RBE3, CERIG, and CP commands.

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Specifying Geometry • You must determine which Behavior best represents the actual loading. Note that this option has no effect if the boundary condition is scoped to a rigid body in which case a Rigid behavior is always used. Presented below are examples of the Total Deformation resulting from the same Remote Displacement (illustrated above), first using a Rigid formulation, then using a Deformable formulation, and finally the Coupled formulation. • For Remote Boundary Conditions applied to an edge or edges of a line body that are colinear, the deformable behavior is invalid. As such, the scoped entities exhibit rigid behavior even if a deformable formulation is specified, and a warning is issued in the Message Window. • All remote boundary conditions are associative, meaning they remember their connection to the geometry. Their location however does not change. If you want the location to be associative, create a coordinate system on the particular face and set the location to 0,0,0 in that local coordinate system. • If the geometry to which a Remote Point is scoped becomes suppressed, the Remote Point also becomes suppressed. Once the geometry is Unsuppressed, the Remote Point becomes valid again. • Remote boundary conditions scoped to a large number of elements can cause the solver to consume excessive amounts of memory. Point masses in an analysis where a mass matrix is required and analyses that contain remote displacements are the most sensitive to this phenomenon. If this situation occurs, consider modifying the Pinball setting to reduce the number of elements included in the solver. Forcing the use of an iterative solver may help as well. Refer to the troubleshooting section for further details. • If a remote boundary condition is scoped to rigid body, the underlying topology on which the load is applied is irrelevant. Since the body is rigid, the loading path through the body will be of no consequence; only the location at which the load acts. For additional MAPDL specific information, see the Multipoint Constraints and Assemblies section as well as KEYOPT(2) in the Mechanical APDL Contact Technology Guide.

Note To apply a remote boundary condition scoped to a surface more than once (for example, two springs), you must do one of the following: • Set scoped surface Behavior to Deformable. • Change scoping to remove any overlap. • Leverage the Pinball Region option.

Remote Point Features Use the following tools to get the most out of the Remote Point feature. • View Remote Points through Connection Lines • Promote Remote Points • Program Remote Points with Commands Objects

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Remote Point

View Remote Points through Connection Lines The connection between the underlying geometry associated with a remote point and the remote point itself can be visualized by connection lines. You can enable this feature through the Show Connection Lines property under Graphics in the Details view of the Remote Points object. If a mesh was generated, the connection lines are drawn between a remote point and the nodes on the corresponding meshed underlying geometry. The connection lines take the Pinball radius into account, and only those nodes that are inside that radius will be connected with the remote point. Any remote loads that have been promoted to reference remote points will have these lines drawn when their object is selected as well. An example illustration of connection lines is shown below.

See the Viewing and Exporting Finite Element Connections topic in the Solution Information Object section of the Help for additional information about the ability to view and work with connection lines.

Promote Remote Points The Promote Remote Point feature helps you add a remote point from the context menu for remote boundary conditions. When you use Promote Remote Point, Workbench adds a remote point object with the remote boundary condition name and the associated data in the Project tree. To add a remote point from a remote boundary condition: 1.

On the Environment context toolbar, select the appropriate boundary condition.

2.

Right-click the remote boundary condition object, and then select Promote Remote Point. A remote point with the boundary condition name and data is added to the Project tree.

3.

In the Project tree, select the new remote point object and modify its data as necessary.

Note This option is not available for objects scoped as a Direct Attachment, such as Springs, Joints, Beams, or a Point Mass. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Specifying Geometry

Program Remote Points with Commands Objects A Commands object can be placed in the tree as a child object of a Remote Point providing you programmable access to the Remote Point pilot node. This is useful if you wish to apply conditions to the Remote Point that are not supported in Mechanical, such as beam or constraint equations.

Point Mass You can idealize the inertial effects from a body using a Point Mass. Applications include applying a force with an acceleration or any other inertial load; or adding inertial mass to a structure, which affects modal and harmonic solutions. To define a Point Mass: 1. Select the Geometry object (or a child object). 2. You can then add a Point Mass object by: • Selecting Point Mass from the Geometry toolbar. or… • Right-clicking the mouse button and selecting Insert>Point Mass from the context menu. or… • Select the desired geometry in the graphics window, right-click the mouse, and then select Insert>Point Mass from the context menu. 3. Specify the Scoping Method property as either Geometry Selection, Named Selection, or Remote Point. Based on the selection made in this step, select a: • geometry (faces, edges, or vertices) and click Apply in the Details view for the Geometry property. or… • single node and click Apply in the Details view for the Geometry property. In order to select an individual node, you need to first generate a mesh on the model, and then choose the Show Mesh button on the Graphics Options Toolbar, and then specify Select Mesh as the Select Type from the Graphics Toolbar. or… • user-defined node-based named selection from the drop-down list of the Named Selection property. or… • user-defined remote point from the drop-down list of the Remote Point property. or… 4. Specify the Point Mass as a Remote Attachment (default) or a Direct Attachment using the Applied By property. The Remote Attachment option uses either a user-defined or a system-generated Remote Point as a scoping mechanism. Remote Attachment is the required Applied By property setting if the geometry scoping is to a single face or multiple faces, a single edge or multiple edges, or multiple vertices.

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Thermal Point Mass The Direct Attachment option allows you to scope directly to a single vertex (Geometry) or a node (using an individually selected node or a node-based Named Selection) of the model. 5. Enter a Mass value. 6. Modify Point Mass object Details view properties as needed. The location of the Point Mass can be anywhere in space and can also be defined in a local coordinate system if one exists. The default location is at the centroid of the geometry. The Point Mass will automatically be rotated into the selected coordinate system if that coordinate system differs from the global coordinate system. You can also input moment of inertia values for each direction. A Point Mass is considered a remote boundary condition if you specify it as a Remote Attachment. Refer to the Remote Boundary Conditions (p. 833) section for a listing of all remote boundary conditions and their characteristics.

Support Limitations A Point Mass cannot: • be applied on any shared topology surface. • span multiple bodies if the Stiffness Behavior of the bodies is declared as Rigid (see Rigid Bodies section for additional information). • be applied to a vertex scoped to an end release.

Thermal Point Mass For Transient Thermal analyses, you can idealize the thermal capacitance of a body using a thermal point mass. Thermal Capacitance replaces the need to calculate the body’s internal thermal gradient. The Thermal Point Mass is commonly used as a medium to store or draw heat from surrounding objects. Applications include the heat dissipation of refrigerators, cooling electronic devices, and heat sinks of computer motherboards. This section examines the following feature applications and requirements: • Apply Thermal Point Mass Object • Behavior Property Specifications • Support Limitations

Apply Thermal Point Mass Object To define a Thermal Point Mass in your Transient Thermal analysis: 1. Select the Geometry object (or a child object). 2. You can then add a Thermal Point Mass object by: • Selecting Thermal Point Mass from the Geometry toolbar. or…

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Specifying Geometry • Right-clicking the mouse button and selecting Insert>Thermal Point Mass from the context menu. or… • Select the desired geometry in the graphics window, right-click the mouse, and then select Insert>Thermal Point Mass from the context menu. 3. Specify the Scoping Method property as either Geometry Selection, Named Selection, or Remote Point. Based on the selection made in this step, select a: • face, edge, or vertex of a solid or surface model or on an edge or vertex of a surface model and click Apply in the Details view for the Geometry property. or… • single node and click Apply in the Details view for the Geometry property. In order to select an individual node, you need to first generate a mesh on the model, and then choose the Show Mesh button on the Graphics Options Toolbar, and then specify Select Mesh as the Select Type from the Graphics Toolbar. or… • user-defined node-based named selection from the drop-down list of the Named Selection property. or… • user-defined remote point from the drop-down list of the Remote Point property. 4. Specify the Thermal Point Mass as a Remote Attachment (default) or a Direct Attachment using the Applied By property. The Remote Attachment option uses either a user-defined or a system-generated Remote Point as a scoping mechanism. Remote Attachment is the required Applied By property setting if the geometry scoping is to a single face or multiple faces, a single edge or multiple edges, or multiple vertices. The Direct Attachment option allows you to scope directly to a single vertex (Geometry) or a node (using an individually selected node or a node-based Named Selection) of the model. 5. Modify coordinate system properties as needed. 6. Enter a Thermal Capacitance value. Thermal Capacitance refers to ability of the material to store heat. The higher the thermal capacitance, the more heat can be stored for each degree rise in temperature of the Thermal Point Mass. 7. When the Thermal Point Mass is defined as a Remote Attachment, the Behavior property displays: define as Isothermal, Coupled, or Heat-Flux Distributed. See the Behavior Property Specifications topic below for additional information about how to make the appropriate selection. 8. Modify additional Thermal Point Mass object Details view properties as needed. The location of the Thermal Point Mass can be anywhere in space. The default location is at the centroid of the geometry. If you specify a Thermal Point Mass (which resembles a Point Mass) as a Remote Attachment, it will act like a remote boundary condition because the Thermal Point Mass is not applied directly to a node of the model. Refer to the Remote Boundary Conditions section of the Help for a listing of all remote boundary conditions and their characteristics.

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Cracks

Behavior Property Specifications The Thermal Point Mass includes three Behavior options in the Details View that control its interaction with the bodies in the geometry selection: Isothermal, Coupled, and Heat-Flux Distributed: • For the Isothermal behavior, temperatures throughout the geometry selections and the Thermal Point Mass are constrained to be the same. The following is an example of a Thermal Point Mass using Isothermal behavior applied to the FACE while a temperature boundary condition is located at the EDGE. While there is a temperature distribution from the boundary condition (EDGE) up to the surface (FACE), the temperature on the FACE in the pinball region, itself takes a single value that matches that of the Thermal Point Mass.

• For Heat-Flux Distributed behavior, however, the temperature of the geometry selection and the point mass are not constrained to be the same. The temperature of the Thermal Point Mass becomes a weighted average of those on the geometry selection. For comparison, the previous example has been modified to use the Heat-Flux Distributed behavior. The FACE, no longer constrained to be isothermal to the point mass, displays a gradient.

• For Coupled behavior, the geometry has the same DOF solution on its underlying nodes as the remote point location. This formulation is similar to the MAPDL constraint defined by the CP command.

Support Limitations A Thermal Point Mass cannot be applied: • on any shared topology surface. • to a vertex scoped to an end release.

Cracks A crack is characterized by its shape, crack front/tip, crack discontinuity plane, crack normal, and crack direction. A crack front in three dimensional analyses represents the line of separation of the discontinuRelease 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Specifying Geometry ous crack surface. The same is represented by a crack tip in two dimensional analyses. A crack inside ANSYS Mechanical is defined using a Crack object or Pre-Meshed Crack object. These objects can be inserted under the Fracture folder. Crack objects, for which you define geometry parameters that define the generated crack mesh, is used to analyze crack front. Internally, the crack mesh generation is performed after the creation of the base mesh. The geometric parameters define the semi-elliptical shape of the crack in three dimensional analyses. The crack definition is complete only after the successful generation of the crack mesh. By default, the crack mesh generation automatically creates a node-based named selection for the crack front under the crack object. For information about the Crack object that uses an internally generated mesh, see Fracture Meshing in the Meshing User’s Guide. A Pre-Meshed Crack definition assumes that the crack meshes, representing the discontinuity or flaw in the structure, have already been generated. In other words, the pre-meshed crack does not internally generate the crack mesh using Fracture Meshing, as the Crack object does, but instead assumes that the crack mesh has been generated beforehand. A Pre-Meshed Crack object uses a node-based named selection to analyze crack front; this nodal named selection is required for the computation of fracture parameters. If a geometric edge represents a crack front, you must first convert it to a node-based named selection using the Worksheet criteria before it can be used by the Pre-Meshed crack object. See the next section, Defining a Pre-Meshed Crack (p. 473), for more information on the Pre-Meshed Crack. The orientation of the crack plays a vital role in the fracture parameter calculations. The coordinate system assigned to a Crack or Pre-Meshed Crack object must be defined such that the y-axis is normal to the crack surface while the x-axis is pointing along the crack extension direction. For the Crack object, the x-axis of coordinate system must be aligned normal to the surface of the scoped geometric entity, which implies that cracks must be perpendicular to the surface (cracks cannot be created at an incline). To achieve this alignment, create a coordinate system as described in Creating a Coordinate System Based on a Surface Normal (p. 487) and assign the created coordinate system to the Crack object. For the Pre-Meshed Crack object, the origin of the coordinate system must be located on the open side of the crack. After the crack mesh is generated, a warning message Mesher has aligned X-axis to the anchor face normal direction. Please orient the crack coordinate system to the face normal direction for accurate computation of fracture parameters Indicates that one of the active crack coordinate systems is not oriented correctly, which may lead to inaccurate computation of fracture parameters. To identify which coordinate system is not oriented properly, set the Crack coordinate orientation variable to 1 (active) in the Variable Manager. Then re-generate the crack mesh. The error message shown in the Messages window indicates the Crack object that requires coordinate system modification. Orient the respective coordinate system correctly; for more information, see Creating a Coordinate System Based on a Surface Normal (p. 487). After correcting the improperly defined coordinate systems for all cracks, reset the Crack coordinate orientation variable to inactive. Note: The graphical view of the crack may differ from the mesh generated. Possible reasons include: • A crack definition unsuitable for valid mesh creation may result in some layers being “peeled off” to create a valid mesh. • The crack contour may be shrunk to fit into the mesh domain.

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Cracks • The crack coordinate system may be changed to align it to surface normal. • The center of the crack may be changed to create the crack on the surface. • The crack is meshed with gradation from the contour center to the outside results in difficulty distributing the crack mesh. • The offset of the crack is not suitable for the crack contour, resulting in a contour that must be reduced to ensure all element contours fit into the template.

Defining a Pre-Meshed Crack A Pre-Meshed Crack is based on a previously-generated mesh and uses a node-based named selection to analyze crack fronts. In addition to cracks modeled in CAD and meshed manually in the Mechanical Application, this feature is also useful when you have a pre-existing mesh generated from an external source and imported to the existing database using FE Modeler. The referenced named selection must contain references only to nodes. Selecting the named selection is done through the Details view of the Pre-Meshed Crack object by selecting from the list of valid named selections in the Crack Front (Named Selection) property. Named selections that contain only nodes are offered as choices.

Note Before defining a pre-meshed crack, you must have defined at least one node-based named selection. For more information on named selections, see Named Selections (p. 429). As an alternative, a geometric based named selection can be converted into a node-based based named selection using the Worksheet. For more information, see Specifying Named Selections using Worksheet Criteria (p. 434). To define a pre-meshed crack: 1.

Select the Model object in the Tree Outline.

2.

Insert a Fracture object into the Tree by right-clicking the Model object and selecting Insert > Fracture.

Note Only one Fracture object is valid per Model.

3.

Insert a Pre-Meshed Crack object into the Tree by right-clicking the Fracture object and selecting Insert > Pre-Meshed Crack.

4.

In the Details View: • For 2D analysis, for Crack Tip (Named Selection), select the node-based named selection to which the crack definition will be scoped.

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Specifying Geometry • For 3D analysis, for Crack Front (Named Selection), select the node-based named selection to which the crack definition will be scoped.

Note For a complete Pre-Meshed Crack definition, you must have previously defined the scoped node-based named selection and generated all crack meshes.

5.

To further define the crack, use the following controls in the Details View. • Coordinate System: Specifies the coordinate system that defines the position and orientation of the crack. The Y axis of the specified coordinate system defines the crack surface normal. The origin of the coordinate system represents the open side of the crack. You can select the default coordinate system or a local coordinate system that you have defined. The default is the Global Coordinate System. The valid coordinate system must be of type Cartesian. • Solution Contours: Specifies the number of contours for which you want to compute the fracture result parameters. • Suppressed: Toggles suppression of the Pre-Meshed Crack object. The default is No.

Note The Pre-Meshed Crack object is suppressed automatically if the scoped body is suppressed.

Interface Delamination and Contact Debonding Adhesives are commonly used to bond structural components into assemblies or to bond layers of material into composite laminates. Simulations often assume the bonding layer to be of infinite strength, but you may want to model the progressive separation of the adhesive as it reaches some known criteria, such as a stress limit. Of the existing theories that define these failure criteria, Mechanical supports the Cohesive-Zone Model (CZM) method and the Virtual Crack Closure Technique (VCCT) method. (See the Cohesive Zone Material (CZM) Model section of the Mechanical APDL Theory Reference and the VCCTBased Crack Growth Simulation section of the Mechanical APDL Structural Analysis Guide for more information about these methods.) In either case, the separation occurs along a predefined interface and cannot propagate in an arbitrary direction Mechanical supports the following features for modeling interface delamination and debonding: • Interface Delamination – utilizes MAPDL interface elements (INTER202 through INTER205) and supports the CZM and VCCT methods. Neither method supports interfaces with lower order triangle faces. Specifically, a prism with a triangle face on the interface or a tetrahedral element with a face on the interface. And, the VCCT does not support higher order elements. • Contact Debonding utilizes MAPDL contact elements (CONTA171 through CONTA177) and supports the CZM method. For additional technical information about Interface Delamination, see the Modeling Interface Delamination with Interface Elements section of the Mechanical APDL Structural Analysis Guide and for 474

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Interface Delamination and Contact Debonding more information about Contact Debonding, see the Modeling Interface Delamination with Contact Elements section. See the Interface Delamination Application and Contact Debonding Application sections for the steps to specify and configure these features. In addition, if you are using the ANSYS Composite PrepPost (ACP) application in combination with the Interface Delamination feature, see the steps in the Interface Delamination and ANSYS Composite PrepPost (ACP) section.

Analysis Type Requirements Interface Delamination is supported by Static Structural and Transient Structural analyses only. Any analysis type may contain a Contact Debonding object, but only the Static Structural and Transient Structural analyses support the progressive separation of an interface. Contact Debonding also supports linear perturbation, which allows you to simulate the vibration (Pre-stressed Modal) or stability (Linear Buckling) characteristics of a partially delaminated structure. You can also use the modes extracted in the Pre-stressed model to perform Mode Superposition analyses such as Harmonic Response, Response Spectrum, and Random Vibration.

Interface Delamination Application The Interface Delamination feature employs either the Virtual Crack Closure Technique (VCCT) method or the Cohesive-Zone Model (CZM) method for defining failure criteria. The VCCT method is a fracture mechanics based method and therefore requires an initial crack (in the form of a Pre-Meshed Crack) in the geometry. The CZM method uses relationships between the separations and tractions along the interface. Note that the CZM method is sensitive to mesh size and material parameters. The convergence of CZM models can generate issues, such as loading step size and stabilization. You may want to review the Interface Delamination Analysis of Double Cantilever Beam tutorial available in the Appendix B. Tutorials section of the Help. To correctly insert the structural interface elements (INTER202 through INTER205) into the mesh, the Interface Delamination feature requires that the sides of the interface have identical element patterns. Both the VCCT and CZM methods provide the option to use either the Matched Meshing or the Node Matching generation method. Matched Meshing requires that you create a Mesh Match Control at the delamination interface. A Match Control requires that both faces referenced by the Match Control belong to the same part, so it is necessary that you create a multi-body part without shared topology. This can be accomplished in a CAD application, such as DesignModeler. Matched Meshing is the recommended Generation Method because it quickly obtains the matching node pairs from the mesh.

Caution The application will not respect mesh matching controls when one or more mesh Refinement controls exist. This may result in mismatched node pairs and element faces. If using a Match Control is not an option and it is necessary to use the Node Matching method, you must ensure that node pairs and element faces match. Because it is necessary for Mechanical to search

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Specifying Geometry the scoped geometry for matching node pairs within the specified Distance Tolerance, this method can be slower and less robust than the Matched Meshing method.

Note The Interface Delamination feature does not support adaptive mesh refinement. Also see the Interface Delamination Object Reference page for information about the properties of this feature. Apply Interface Delamination To specify Interface Delamination: 1. Insert a Fracture folder in the Tree Outline. The Fracture object becomes active by default. 2. On the Fracture context toolbar: click Interface Delamination. Or, right-click: • the Fracture tree object and select Insert>Interface Delamination. Or… • in the Geometry window and select Insert>Interface Delamination. 3. Select the desired Method: either VCCT (default) or CZM. The properties vary based on your selection. VCCT Method 1. Specify the Failure Criteria Option property: either Energy-Release Rate (default) or Material Data Table. 2. Based on the selected Failure Criteria Option: • If specified as Energy-Release Rate: enter a Critical Rate value. This value determines the energy release rate in one direction. • If specified as Material Data Table: specify a Material. This property defines the energy release rate in all three fracture modes. This property is defined in Engineering Data. See the Static Structural & Transient Structural section of the Engineering Data Help for additional information about the Cohesive Zone properties used by this feature. 3. Based on the Generation Method selected, either Matched Meshing (default) or Node Matching, perform one of the following: Matched Meshing If Matched Meshing, specify a Match Control by selecting a pre-defined Match Control. The Match Control that is referenced by the property requires that the delamination occurs between two independent parts that have the same element/node pattern. Node Matching If Node Matching, specify: a. Scoping Method b. Source 476

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Interface Delamination and Contact Debonding c. Target

Note This option assumes that the existing mesh is already matched.

4. Define the Initial Crack by selecting a user-defined Pre-Meshed Crack. 5. Specify the Auto Time Stepping property as either Program Controlled (default) or Manual. The following properties can be modified if Manual is selected, otherwise they are read-only. a. Initial Time Step b. Minimum Time Step c. Maximum Time Step

Note • The Auto Time Stepping property must be set to On in the Step Controls category of the Analysis Setting object. • Time stepping values take effect when crack growth is detected.

6. If Node Matching is selected as the Generation Type, the Node Matching Tolerance category displays. Specify the Tolerance Type property as either Program Controlled (default) or Manual. The Distance Tolerance property can be modified if Manual is selected, otherwise it is read-only. CZM Method 1. Specify a Material. This property is defined in Engineering Data. See the Static Structural & Transient Structural section of the Engineering Data Help for additional information about the Cohesive Zone properties used by this feature. 2. Define the Generation Method property as either Matched Meshing (default) or Node Matching. 3. Based on the Generation Method selected, either Matched Meshing or Node Matching, perform one of the following: Matched Meshing For the Matched Meshing Generation Method, select a pre-defined Match Control. The Match Control that is referenced by the property requires that the delamination occurs between two independent parts that have the same element/node pattern. Node Matching If Node Matching is the Generation Method, then specify: a. Scoping Method b. Source Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Specifying Geometry c. Target

Note This option assumes that the existing mesh is already matched.

4. If Node Matching is selected as the Generation Type, the Node Matching Tolerance category displays. Specify the Tolerance Type property as either Program Controlled (default) or Manual. The Distance Tolerance property can be modified if Manual is selected, otherwise it is read-only.

Contact Debonding Application Debonding simulations begin by defining contact regions along an interface that will separate. The properties for the contact elements require that the contact Type be Bonded or No Separation contact and that the Formulation is specified as the Augmented Lagrange method or the Pure Penalty method. The Contact Debonding object specifies the pre-existing contact region (defined using the Connections feature) that you intend to separate and it also references the material properties defined in Engineering Data. You must select the material properties from the Cohesive Zone category with type SeparationDistance based Debonding or Fracture-Energies based Debonding. See the Static Structural & Transient Structural section of the Engineering Data Help for additional information about the Cohesive Zone properties used by this feature. In addition, you may want to review the Delamination Analysis using Contact Based Debonding Capability tutorial available in the Appendix B. Tutorials section of the Help. Apply Contact Debonding To specify Contact Debonding: 1. Insert a Fracture folder in the Tree Outline. The Fracture object becomes active by default. 2. On the Fracture context toolbar: click Contact Debonding. Or, right-click: • the Fracture tree object and select Insert>Contact Debonding. Or… • in the Geometry window and select Insert>Contact Debonding. 3. Select a Material. 4. Select a Contact Region.

Tip To automatically generate a Contact Debonding object, select a Contact Region and drag and drop it onto the Fracture folder.

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Interface Delamination and Contact Debonding Also see the Contact Debonding Object Reference Help page for information about the properties of this feature.

Interface Delamination and ANSYS Composite PrepPost (ACP) Mechanical allows you to import interface layer(s) from the ANSYS Composite PrepPost (ACP) application. You can define interface layers in ACP, import them into Mechanical, and use them to define Interface Delamination objects. You can automatically insert Interface Delamination objects into the Fracture folder when importing composite section data into Mechanical by setting the Create Delamination Objects property (see Specifying Options) to Yes. Alternatively, you can generate Interface Delamination objects automatically after you have imported Composite Section data by selecting the Generate All Interface Delaminations option in the context menu of the Fracture object.

Unexpected Penetration during Nonlinear Analysis If you experience penetration at the interface layers during separation, you may wish to create a Contact condition for the interface where the penetration is taking place. A Contact Region can be applied to a Pre-Generated Interface provided by ACP. Although all contact Type settings are supported for PreGenerated Interfaces, the Frictionless setting is recommended for this case when specifying the contact condition. Other contact properties can be set to the default, Program Controlled, settings.

Apply Interface Delamination via ACP To specify Interface Delamination using the ACP application:

Note The following steps assume that you have properly defined your interface layer in the ACP application. VCCT Method (Default) 1. From the Workbench Project page, link your Static Structural or Transient Structural analysis to the ACP (Pre) system and then launch Mechanical. A Fracture folder is automatically created and includes an Interface Delamination object. 2. Select the new Interface Delamination object. 3. Specify the Failure Criteria Option property: either Energy-Release Rate (default) or Material Data Table. 4. Based on the selected Failure Criteria Option: • If specified as Energy-Release Rate: enter a Critical Rate value. This value determines the energy release rate in one direction. • If specified as Material Data Table: specify a Material. This property defines the energy release rate in all three fracture modes. This property is defined in ACP. 5. The automatic setting for the Generation Method property is Pre-Generated Interface. Accept this setting.

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Specifying Geometry 6. As necessary, select the appropriate Interface Layer from the Interface property drop-down menu. 7. Define the Initial Crack by selecting the Pre-Meshed Crack created by ACP. 8. Specify the Auto Time Stepping property as either Program Controlled (default) or Manual. The following properties can be modified if Manual is selected, otherwise they are read-only. a. Initial Time Step b. Minimum Time Step c. Maximum Time Step

Note • The Auto Time Stepping property must be set to On in the Step Controls category of the Analysis Setting object. • Time stepping values take effect when crack growth is detected.

CZM Method 1. From the Workbench Project page, link your Static Structural or Transient Structural analysis to the ACP (Pre) system and then launch Mechanical. A Fracture folder is automatically created and includes an Interface Delamination object. 2. Select the new Interface Delamination object. 3. Specify the Material property. This property provides a fly-out menu to make a material selection that was defined in the ACP (Pre) system. 4. The automatic setting for the Generation Method property is Pre-Generated Interface. Accept this setting. 5. As necessary, select the appropriate Interface Layer from the Interface property drop-down menu.

Gaskets Gasket joints are essential components in most structural assemblies. Gaskets as sealing components between structural components are usually very thin and made of various materials, such as steel, rubber and composites. From a mechanics perspective, gaskets act to transfer force between components. The primary deformation of a gasket is usually confined to one direction, namely, through thickness. The stiffness contributions from membrane (in plane) and transverse shear are much smaller in general compared to the through thickness. A typical example of a gasket joint is in engine assemblies. A thorough understanding of the gasket joint is critical in engine design and operation. This includes an understanding of the behavior of gasket joint components themselves in an engine operation, and the interaction of the gasket joint with other components. The overall procedure for simulating gaskets in ANSYS Workbench is to run a static structural analysis and perform the following specialized steps:

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Gaskets 1. Specify a material with a valid gasket model in Engineering Data. 2. Set the Stiffness Behavior of the Body object to Gasket. This produces a Gasket Mesh Control object beneath the Body object. 3. Adjust Details view settings for the Gasket Mesh Control object and generate the mesh. 4. Solve and review the gasket result. Refer to the following sections for further details. Gasket Bodies Gasket Mesh Control Gasket Results

Gasket Bodies You can conveniently specify a solid body to be treated as a gasket by settings its Stiffness Behavior to Gasket. A Gasket body will be meshed with special elements that have a preferential or sweep direction. The mesh will consist of a single layer of solid elements with all mid-side nodes dropped along this direction. You must also specify a material with a valid gasket model in Engineering Data. The following restrictions apply to Gasket bodies: • Gasket bodies are valid only in static structural analyses. • Gasket bodies are valid for 3D solids only, that is, 2D gasket bodies cannot be specified. • A valid gasket material model must be specified. • In addition to gasket bodies, a multibody part may also include flexible bodies but not rigid bodies.

Gasket Mesh Control Upon specifying a Gasket body, a Gasket Mesh Control object is added beneath the Body object in the tree. The meshing method for the control will be set to sweep and allow you to indicate the sweep direction. This control instructs the application to drop mid-side nodes on gasket element edges that are parallel to the sweep direction. To use gasket element meshing after setting the 3D Body object’s Stiffness Behavior to Gasket: 1. In the Details view of the Gasket Mesh Control object, ensure that Mesh Method is set to Sweep and Src/Trg Selection is set to Manual Source. These are the default settings. 2. Select a Source face. The selected face must lie on the gasket body. 3. The Target selection is Program Controlled by default. If desired, you can set Src/Trg Selection to Manual Source and Target. Then you can choose Target manually. 4. If desired, you can change the value of the Free Face Mesh Type control to All Quad, Quad/Tri, or All Tri. When generating the gasket element mesh, the application drops the midside nodes on the edges that are parallel to the sweep direction. For example, consider the mesh shown below. To define the sweep method, Src/Trg Selection was set to Manual Source; one face (the “top” face) was selected for Source.

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Specifying Geometry In the resulting mesh, the gasket element faces on the source and target are quadratic, but the faces on the sides are linear.

Note When Element Midside Nodes is set to either Program Controlled or Kept results in quadratic elements with midside nodes are dropped in the normal direction. When Element Midside Nodes is set to Dropped the midside nodes are dropped, resulting in linear elements.

Gasket Results Specialized results are available for analyzing gaskets. See Gasket Results (p. 948) for details.

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Setting Up Coordinate Systems All geometry in the Mechanical application is displayed in the global coordinate system by default. The global coordinate system is the fixed Cartesian (X, Y, Z) coordinate system originally defined for a part. In addition, you can create unique local coordinate systems to use with springs, joints, various loads, supports, and result probes. Cartesian coordinates apply to all local coordinate systems. In addition, you can apply cylindrical coordinates to parts, displacements, and forces applied to surface bodies.

Note Cylindrical coordinate systems are not supported by the Explicit Dynamics solvers, but may be used for some postprocessing operations. Annotations are available for coordinate systems. You can toggle the visibility of these annotations in the Annotation Preferences dialog box. For more information, see Specifying Annotation Preferences (p. 119). The following topics are covered in this section: Creating Coordinate Systems Importing Coordinate Systems Applying Coordinate Systems as Reference Locations Using Coordinate Systems to Specify Joint Locations Creating Section Planes Create Construction Surface Transferring Coordinate Systems to the Mechanical APDL Application

Creating Coordinate Systems The following topics involve the creation of local coordinate systems: Initial Creation and Definition Establishing Origin for Associative and Non-Associative Coordinate Systems Setting Principal Axis and Orientation Using Transformations Creating a Coordinate System Based on a Surface Normal See the Coordinate System Object Reference page of the Help for additional information about the categories and properties of the Coordinate System object.

Initial Creation and Definition Creating a new local coordinate system involves adding a Coordinate System object to the tree and addressing items under the Definition category in the Details view.

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Setting Up Coordinate Systems To create and define a new local coordinate system: 1. Highlight the Coordinate Systems folder in the tree and choose the Coordinate Systems button from the toolbar or from a right-click and select Insert> Coordinate System. A Coordinate System object is inserted into the tree.

The remainder of the toolbar buttons involve the use of transformations discussed in a later section. 2. In the Details view Definition group, set the following: a. Type: set to Cartesian or Cylindrical. b. Coordinate System: to Program Controlled or Manual. This assigns the coordinate system reference number (the first argument of the Mechanical APDL LOCAL command). Choose Program Controlled to have the reference number assigned automatically, or choose Manual to assign a particular reference number in the Coordinate System ID field for identification or quick reference of the coordinate system within the input file. You should set the Coordinate System ID to a value greater than or equal to 12. If you create more than one local coordinate system, you must ensure that you do not duplicate the Coordinate System ID. c. Suppressed: Yes or No (default). If you choose to suppress a coordinate system, you remove the object from further treatment, write no related data to the input deck, and cause any objects scoped to the coordinate system to become underdefined (therefore invalidating solutions).

Establishing Origin for Associative and Non-Associative Coordinate Systems After creating a local coordinate system, you can further designate it as being associative or non-associative with geometry and define its origin. • An associative coordinate system remains joined to the face or edge on which it is applied throughout preprocessing. Its position and orientation is thus affected by modifications to the geometry during updates and through the use of the Configure tool. The coordinate system does not follow the geometry and its mesh during the solution. • A non-associative coordinate system is independent of any geometry. You establish the origin for either an associative or non-associative coordinate system in the Origin category in the Details view. The category provides the following properties: • Define By: options include Geometry Selection, Named Selection, and Global Coordinates. • Geometry: this property is a graphical selection tool. The selection you make using this property defines the values populated in the Origin X, Y, and Z properties.

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Creating Coordinate Systems • Origin X, Origin Y, and Origin Z: automatically populated by the Geometry property selection or you can manually enter values.

Note A coordinate system’s origin cannot be located by scoping it to a line body. If you wish to put the origin at the center of the line body, please select the edge of the line body for the origin selection instead. To establish the origin for an associative coordinate system: 1. Set the Define By property to Geometry Selection or Named Selection. For a Reference Coordinate System attached to a joint, work with the Orientation About Principal Axis category to make the coordinate system associative. If you select: • Geometry Selection a. Graphically select geometry (vertex or vertices, edge, face, cylinder, circle, or circular arc) or one node or multiple nodes. b. Select the Geometry field and then select Click to Change. c. Click Apply. A coordinate system symbol displays at the centroid of your selection. The centroid is defined as the simple average (unweighted by length, area, or volume) of the individual centroids of your geometry selections. • Named Selection: Select a user-defined Named Selection from the Named Selection drop-down menu. Preselecting one or more topologies and then inserting a Coordinate System will automatically locate its origin as stated above. To establish the origin for a non-associative coordinate system: •

In the Details view Origin group, set Define By to Global Coordinates. You then define the origin in either of the following ways: • Selecting any point on the exterior of the model: 1. Set Define By to Global Coordinates. 2. Select the Click to Change field of the Location property. 3. Select the Hit Point Coordinate ( ) button on the Graphics Toolbar. This feature allows you to move the cursor across the model and display coordinates. 4. Select the desired origin location on the model. A small cross hair appears at the selected location. You can change the cross hair location as desired. 5. Click Apply in the Location property field. A coordinate system symbol displays at the origin location. Note that the coordinates display in Origin X, Y and Z properties of the the Details view.

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Setting Up Coordinate Systems You can change the location by repositioning the cursor, clicking at the new location, and then clicking Click to Change and Apply, or by editing the coordinates in the Details view. • Selecting any point using the average location of selected nodes: 1. Set Define By to Global Coordinates. 2. Choose Click to Change in the Location row. 3. Click the Show Mesh button.

4. Choose the Select Mesh option in the Select Type (Geometry/Mesh) menu.

5. Select as many nodes as desired and then click Apply. The origin coordinate system is specified on the model based on the average location of the selected nodes. • Entering the coordinates directly in the Details view. 1. Set Define By to Global Coordinates. 2. Type the Origin X, Y, Z coordinates. The origin will be at this location.

Setting Principal Axis and Orientation The definition of the coordinate system involves two vectors, the Principal Axis vector and the Orientation About Principal Axis vector. The coordinate system respects the plane formed by these two vectors and aligns with the Principal Axis. Use the Principal Axis category in the Details view to define one of either the X, Y, or Z axes in terms of a: • Geometry Selection – Associatively align axis to a topological feature in the model. When a change occurs to the feature, the axis automatically updates to reflect the change. • Fixed Vector – Depending upon the Geometry Selection, this option preserves the current Geometry Selection without associativity. When a change occurs to the feature the axis will not update automatically to reflect that change. • Global X, Y, Z axis – Force the axis to align to a global X, Y, or Z axis. • Hit Point Normal – Align the axis along a normal vector which represents the normal direction of the local surface curvature of the hit point. You then select a point on the screen to define the Hit Point Normal and orient the primary axis. For information on creating a coordinate system aligned with the hit point, see Creating a Coordinate System Based on a Surface Normal (p. 487). Use the Orientation About Principal Axis category in the Details view to define one of the orientation X, Y, or Z axes in terms of the Default, Geometry Selection, the Global X, Y, Z axes, or Fixed Vector.

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Creating Coordinate Systems

Using Transformations Transformations allow you to “fine tune” the original positioning of the coordinate system. Options are available for offsetting the origin by a translation in each of the x, y and z directions, as well as by rotation about each of the three axes. Flipping of each axis is also available. To exercise transformations, you use buttons on the Coordinate System Context Toolbar and settings in the Transformations category in the Details view. To transform a coordinate system: 1.

Choose a transformation (translation, rotation, or flip) from the Coordinate Systems toolbar.

Entries appear in the Details view as you add transformations. 2.

Enter information in the Details view for each transformation.

3.

If required: • Reorder a transformation by highlighting it in the Details view and using the Move Transform Up or Move Transform Down toolbar button. • Delete a transformation by highlighting it in the Details view and using the Delete Transform toolbar button.

Creating a Coordinate System Based on a Surface Normal You can orient a coordinate system based on the surface normal. You have two options. You can orient the principal axis based on the hit point normal of an existing coordinate system, or you can create an aligned coordinate system based on the hit point.

Orienting the Principal Axis by Hit Point Normal To orient the principal axis based on the hit point normal of an existing coordinate system: 1.

Create a coordinate system.

2.

In the Details view, define the principal axis by Hit Point Normal.

3.

In the Graphics window, select a point.

4.

In the Details view, click Apply for Hit Point Normal.

For more information, see Setting Principal Axis and Orientation (p. 486).

Creating a Coordinate System Aligned with a Hit Point To create an aligned coordinate system based on the hit point:

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Setting Up Coordinate Systems 1.

Enable Hit Point Coordinate mode by toggling the Hit Point Coordinate button in the Graphics toolbar.

2.

In the Graphics window, select a point.

3.

Right-click the Graphics window and select Create Coordinate System Aligned with Hit Point. Mechanical creates a coordinate system on the location of hit point with the primary axis aligning along the hit point normal. If a hit point is not defined, Mechanical creates a coordinate system on the location of {0,0,0}, with the axis the same as the global coordinate system.

Importing Coordinate Systems Coordinate systems defined when geometry is imported from DesignModeler, Creo Parametric, or SolidWorks will automatically be created in the Mechanical application. For more information, see the Attaching Geometry section under DesignModeler, or see the Notes section under Creo Parametric or SolidWorks in the CAD Integration section of the ANSYS Workbench help. If you update the model in the Mechanical application, coordinate systems from these products are refreshed, or newly defined coordinate systems in these products are added to the model. If a coordinate system was brought in from one of these products but changed in the Mechanical application, the change will not be reflected on an update. Upon an update, a coordinate system that originated from DesignModeler, Creo Parametric, or SolidWorks will be re-inserted into the object tree. The coordinate system that was modified in the Mechanical application will also be in the tree.

Applying Coordinate Systems as Reference Locations Any local coordinate systems that were created in the Mechanical application, or imported from DesignModeler, Creo Parametric, or SolidWorks, can be applied to a part, or to a Point Mass, Spring, Acceleration, Standard Earth Gravity, Rotational Velocity, Force, Bearing Load, Remote Force, Moment, Displacement, Remote Displacement, or Contact Reaction. This feature is useful because it avoids having to perform a calculation for transforming to the global coordinate system. To apply a local coordinate system: 1.

Select the tree object that represents one of the applicable items mentioned above.

2.

For an Acceleration, Rotational Velocity, Force, Bearing Load, or Moment, in the Details view, set Define By, to Components, then proceed to step 3. For the other items, proceed directly to step 3.

3.

In the Details view, set Coordinate System to the name of the local coordinate system that you want to apply. The names in this drop-down list are the same names as those listed in the Coordinate Systems branch of the tree outline.

Note If you define a load by Components in a local coordinate system, changing the Define By field to Vector will define the load in the global coordinate system. Do not change the Define By field to Vector if you want the load defined in a local coordinate system.

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Creating Section Planes

Using Coordinate Systems to Specify Joint Locations Whenever you create a joint, an accompanying reference coordinate system is also created. The intent of this coordinate system is for positioning the joint. See the Joint Properties (p. 553) section for further details.

Creating Section Planes For viewing purposes, you can use the Create Section Plane option to slice the graphical image of your model based on a predefined coordinate system.

Note The Section Plane feature does not support Cylindrical Coordinate Systems. 1. Select the desired Coordinate Systems object. The User-Defined Coordinate System illustrated here slices the model along the X-Y plane.

2. Right-click the mouse and select Create Section Plane.

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Setting Up Coordinate Systems

As illustrated here, the model is sliced based on the User-Defined Coordinate System.

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Create Construction Surface

Note This option is also available for Coordinate System objects in the Meshing Application.

Create Construction Surface As illustrated below, you can create a Surface Construction Geometry from any existing coordinate system using the right-click feature Create Construction Surface. Right-click Menu for Create Construction Surface

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Setting Up Coordinate Systems

Details for Surface Object

The Details display the defined coordinate system and allow you to suppress the object if desired.

Transferring Coordinate Systems to the Mechanical APDL Application You can transfer coordinate systems to the Mechanical APDL application using any of the following methods: • Main Menu> Tools > Write Input File… • Load the Mechanical APDL application. • Commands Objects Any coordinate system defined in the Mechanical application and sent to the Mechanical APDL application as part of the finite element model, will be added to the Mechanical APDL application input file as LOCAL commands. For example: /com,*********** Send User Defined Coordinate System(s) *********** local,11,0,0.,0.,0.,0.,0.,0. local,12,1,11.8491750582796,3.03826387968126,-1.5,0.,0.,0. csys,0

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Setting Connections Supported connection features consist of Contact, Mesh Connection, Joint, Spring, Beam Connection, End Release, Spot Weld and Body Interaction (Explicit Dynamics only). Each of these connections can be created manually in the application. Only Contact, Joint, and Mesh Connection can also be generated automatically. This section describes Connections folder, Connection Group folder, Automatic Generated Connections, as well as each connection type as outlined below. Connections Folder Connections Worksheet Connection Group Folder Common Connections Folder Operations for Auto Generated Connections Contact Joints Mesh Connection Springs Beam Connections Spot Welds End Releases Body Interactions in Explicit Dynamics Analyses Bearings

Connections Folder The Connections folder is the container for all types of connection objects except for the three types that can be automatically generated (Contact, Joint, and Mesh Connection). The objects of each of these three types are placed in a sub-folder called the Connection Group folder. As illustrated below, the Details view of the Connections folder provides the following two properties.

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Setting Connections

Auto Detection • Generate Automatic Connection On Refresh: options are Yes (default) or No. This is a setting to turn on/off for auto generation of connection objects when the geometry is refreshed. The process of automatically creating the contact and mesh connection objects is additive. Any existing connection objects of these types that were created manually may be duplicated when the connections are automatically regenerated. To avoid duplication, you should first delete any existing contact and mesh connection objects before the geometry is refreshed.

Note Special conditions apply to updating geometry that includes Spot Welds. The process of automatically creating joint objects is not additive. Any existing joint objects are note duplicated when connections are automatically regenerated. Transparency • Enabled: options are Yes (default) or No. This is a setting to enable or disable transparency of the bodies not associated with the connection in the graphics display.

Connections Worksheet When Connections is selected in the Tree Outline, the Worksheet window supplements the Details view by providing a summary of the contact information, joint information, mesh connection information, and the connections between geometry bodies. In the worksheet, the Show Preferences button enables you to select the worksheet data, and the Generate button generates the content. To toggle on the worksheet:

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Connections Worksheet 1.

Select the Worksheet button on the standard toolbar.

2.

Select the Show Preferences button to view the possible data types.

3.

Select the check boxes for the data types you want to view.

4.

Select the Generate button to generate the content. ANSYS Mechanical remembers the display preferences you select and will default to those in future sessions.

Select Hide Preferences to hide the preferences and Refresh to refresh the worksheet data.

Worksheet Connections Data Types The data types available in the worksheet are described below. You can turn the displayed properties on and off using the right-click menu. Contact Information Displays the properties for each contact. Joint DOF Checker Checks the total number of free degrees of freedom and displays the free DOF, based on the number of unsuppressed parts, fixed constraints, and translation joints. If this number is less than 1, the model may be overconstrained, and you should check the model closely and remove any redundant joint constraints. You can use a Redundancy Analysis to detect redundant joint constraints. Joint Information Displays the name, type, scope, and status of all joints. Mesh Connection Information Displays information about the mesh connections. Spring Information Displays spring connection properties. Beam Information Displays beam connection properties. Connection Matrix Displays a matrix that represents the connections between bodies in the geometry. These connections are color-coded by type (as shown in the legend). In the Preferences, you can choose the type of data to display, in order to filter out unwanted information. Activate the options by checking the selection box beside the Connection Matrix title. The following options can then be selected or deselected as desired. • Show Upper Diagonal • Show Diagonal Marker • Show Unconnected Bodies • Show Suppressed Objects • Bundle Connections The Bundle Connections option is an especially useful tool as it allows you to group Control Connection Types. For example, if you have three Spot Welds contained in the same cell of the Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Connections matrix, activating the Bundle Connections option displays the spot welds as «3 Spot Welds» instead of displaying the individual names of all three within the cell.

Note The matrix displays a grounded connection as a connection to itself. For example, if a grounded joint is scoped to body1, then it will be displayed in the cell of column body1 and row body1. Selection Options Selecting the table, a cell, a row, or a column and the right-clicking the mouse provides a menu of the following options: • Go To Selected Items in Tree: the application displays the associated contact object or objects in the Geometry Window. • Edit Column Width: changes column width (in pixels). You can select multiple columns or rows. A value of zero (default) indicates that the setting is program controlled. • Export (see below)

Note The Connection Matrix is limited to 200 prototypes. Control Connection Types The Control Connection Types display area provides a list of selectable connection features/types that you can choose to display or to not display within the Connection Matrix. Options include: • Contact • Spot Weld • Joint • Mesh Connection • Spring • Beam

Exporting the Connection Matrix You can export a text file version of the Connection Matrix from either the worksheet or the Connections object in the Tree Outline. To export from the worksheet, right-click the Connection Matrix and select Export. To export from the Tree Outline, right-click the Connections object and select Export.

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Connection Group Folder

Connection Group Folder The role of a Connection Group folder is to provide you with the ability to automatically generate Contact, Joint, or Mesh Connection objects for the whole model or for a group of bodies within the model with a tolerance value applied only to this group. Only these three types of connections are provided with the automatic detection capability and only one type of connection objects can be included in a Connection Group folder with the exception of Spot Weld (see details in the Spot Weld section). The generated objects are placed in a Connection Group folder which is automatically renamed to «Contacts», «Joints», or «Mesh Connections» depending on the type. When a model is imported into the Mechanical application, if the Auto Detect Contact On Attach is requested (in the Workbench Tools>Options>Mechanical), auto contact detection is performed using the detection criteria based on the user preferences (in the Mechanical Tools>Options>Connections). Detail steps for auto/manual generating connection objects are presented in the Common Connections Folder Operations for Auto Generated Connections (p. 501) section. The Connection Group has the following properties.

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Definition • Connection Type: options include Contact, Joint, and Mesh Connections. Scope • Scoping Method: options include Geometry Selection (default) and Named Selection. – Geometry – appears if Scoping Method is set to Geometry Selection. – Named Selection – appears if Scoping Method is set to Named Selection. Auto Detection • Tolerance Type: options include Slider, Value, and Use Sheet Thickness. Bodies in an assembly that were created in a CAD system may not have been placed precisely, resulting in small overlaps or gaps along the connections between bodies. You can account for any imprecision by specifying connection detection tolerance. This tolerance can be specified by value when the type is set to Slider and Value,

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Connection Group Folder or sheet thickness of surface bodies when the type is set to Use Sheet Thickness. This option is only applicable to Contact and Mesh Connection and available when the Group By property (see below) is set to None or Bodies. • Tolerance Slider: appears if Tolerance Type is set to Slider. To tighten the connection detection, move the slider bar closer to +100 and to loosen the connection detection, move the slider bar closer to -100. A tighter tolerance means that the bodies have to be within a smaller region (of either gap or overlap) to be considered in connection; a looser tolerance will have the opposite effect. Be aware that as you adjust the tolerance, the number of connection pairs could increase or decrease. • Tolerance Value: appears if Tolerance Type is set to Slider or Value. This field will be read-only if the Tolerance Type is set to Slider showing the actual tolerance value based on the slider setting. When the Tolerance Type is set to Value, you will be able to provide an exact distance for the detection tolerance. After you provide a greater than zero value for the Tolerance Value, a circle appears around the current cursor location as shown below.

The radius of the circle is a graphical indication of the current Tolerance Value. The circle moves with the cursor, and its radius will change when you change the Tolerance Value or the Tolerance Slider. The circle appropriately adjusts when the model is zoomed in or out. • Use Range: appears when the Tolerance Type property is set to Slider or Value. Options include Yes and No (default). If set to Yes, you will have the connection detection searches within a range from Tolerance Value to Min Distance Value inclusive. – Min Distance Percentage: appears if Use Range is set to Yes. This is the percentage of the Tolerance Value to determine the Min Distance Value. The default is 10 percent. You can move the slider to adjust the percentage between 1 and 100. – Min Distance Value: appears if Use Range is set to Yes. This is a read-only field that displays the value derived from: Min Distance Value = Min Distance Percentage * Tolerance Value/100. • Thickness Scale Factor: appears if Tolerance Type is set to Use Sheet Thickness. The default value is 1. For Edge/Edge pairing (see below), the largest thickness among the surface bodies involved is used; however, if the pairing is Face/Edge, the thickness of the surface body with the face geometry is used. • Face/Face: (Contacts only) options include Yes (default) and No. Detects connection between the faces of different bodies. The maximum allowable difference in the normals for which contact is detected is 15 degrees. For Joints, Face/Face is the only detection type allowed. That is why the property does not appear in the Details view when the Connection Type is Joint.

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Setting Connections • Face/Edge: (Contacts and Mesh Connections only) options include Yes, No (default), Only Solid Body Edges and Only Surface Body Edges. Detects connection between faces and edges of different bodies. Faces are designated as targets and edges are designated as contacts. For Only Solid Body Edges, the face to edge connection uses the edges of solid bodies to determine connection with all faces. Likewise, for Only Surface Body Edges, face to edge connection uses only edges of surface bodies to determine connection with all faces. • Edge/Edge: (Contacts and Mesh Connections only) options include Yes and No. Detects connection between edges of different bodies. • Priority: (Contacts and Mesh Connections only) options include All, Face Overrides and Edge Overrides. For very large models the number of connection objects can sometimes become overwhelming and redundant, especially when multiple detection types are chosen. Selecting some type of priority other than Include All will lessen the number of connection objects generated during Create Automatic Connections by giving designated connection types precedence over other types. Face Overrides gives Face/Face option precedence over both Face/Edge and Edge/Edge options. It also gives Face/Edge option precedence over Edge/Edge option. In general, when Face Overrides priority is set with Face/Edge and Edge/Edge options, no Edge/Edge connection pairs will be detected. Edge Overrides gives Edge/Edge option precedence over both Face/Edge and Face/Face options, no Face/Face connections pairs will be detected. • Group By: options include None, Bodies and Parts. This property allows you to group the automatically generated connections objects. Setting Group By to Bodies (default) or to Parts means that connection faces and edges that lie on the same bodies or same parts will be included into a single connection object. Setting Group By to None means that the grouping of geometries that lie on the same bodies or same parts will not occur. Any connection objects generated will have only one entity scoped to each side (that is, one face or one edge). Applications for choosing None in the case of contact are: – If there are a large number of source/target faces in a single region. Choosing None avoids excessive contact search times in the ANSYS solver. – If you want to define different contact behaviors on separate regions with contact of two parts. For example, for a bolt/bracket contact case, you may want to have bonded contact between the bolt threads/bracket and frictionless contact between the bolt head/bracket. • Search Across: This property enables automatic connection detection through the following options: – Bodies (default): Between bodies. – Parts: Between bodies of different parts, that is, not between bodies within the same multibody part. – Anywhere: Detects any connections regardless of where the geometry lies, including different parts. However, if the connections are within the same body, this option finds only Face/Face connections, even if the Face/Edge setting is turned On. • Fixed Joints: (Joint only) options include Yes and No. This property determines if Fixed Joints are to be automatically generated. See the Automatic Joint Creation section for details. • Revolute Joints: (Joint only) options include Yes and No. This property determines if Revolute Joints are to be automatically generated. See the Automatic Joint Creation section for details.

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Common Connections Folder Operations for Auto Generated Connections

Common Connections Folder Operations for Auto Generated Connections You can automatically generate supported connections for a group of bodies in a model and use a separate tolerance value for that group. The supported connection types are Contact Region, Joint, and Mesh Connection. To automatically generate connections for a group of bodies: 1. Insert a Connection Group object under the Connections folder either from the toolbar button or by choosing Insert from the context menu (right mouse click) for this folder. 2. From the Details view of the Connection Group object, select the desired Connection Type. The default is Contact. 3. Select some bodies in the model based on the Scoping Method. The default is Geometry Selection scoped to All Bodies. 4. If applicable, set the Auto Detection properties. Note that these properties will be applied only to scoped geometries for this connection group. 5. Choose Create Automatic Connections from the context menu (right mouse click) for the Connection Group.

Note For small models, the auto contact detection process runs so fast that the Contact Detection Status (progress bar) dialog box does not get displayed. However, for large models with many possible contact pairs, the progress bar dialog box is displayed showing the contact detection progress. If you click the Cancel button on the dialog box while contact detection is processing, the detection process stops. Any contact pairs found by that moment are discarded and no new contacts are added to the tree. The resulting connection objects will be placed under this folder and the folder name will be changed from its default name Connection Group to a name based on the connection type. The folder name for contacts will be Contacts, for mesh connections it will be Mesh Connections, and for joints it will be Joints. Once the Connection Group folder contains a child object, the Connection Type property cannot be changed. Each Connection Group folder will hold objects of the same type and will include a worksheet that displays only content pertaining to that folder. When two or more Connection Group folders are selected and you choose Create Automatic Connections, auto detection for the selected Connection Group folders will be performed. The Create Automatic Connections option is also available from the context menu (right mouse click) for the Connections folder provided there is at least one Connection Group folder present. When you choose this command from the Connections folder, auto detection will be performed for all connection groups under this folder.

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Manually Inserting Connection Objects You can insert any supported connection objects manually either from the toolbar or by choosing Insert from the context menu (right mouse click) on the Connections or Connection Group folder. When inserting a connection object from the Connections folder, a Connection Group object will automatically be created in addition to the connection object itself. When inserting a connection object from a Connection Group folder, if it is an empty folder, any supported type of object can be inserted. However, if the folder already contains at least one object, only objects of the same type can be inserted.

Searching for Duplicate Pairs Generating connections (Contacts, Mesh Connections or Joints) either automatically or manually may result in the same geometry pair being scoped by more than one connection object. This may over constrain the model that may lead to convergence difficulty problems in the solver. If this situation occurs, you can take corrective action by modifying the geometry scoping of the duplicated pairs or by deleting the duplicating connection objects. When generating connection objects automatically, each newly generated connection will be checked against existing connection objects for possible duplicate pairs. If one or more duplicate pairs are found in the existing connection objects, the following warning message will appear in the message box for a connection object that shares the same geometry pair: «This connection object shares the same geometries with one or more connection objects. This may overconstrain the model. Consider eliminating some connection objects.» To find the connection object for a particular message, highlight that message in the message pane and right-click on that message and choose Go To Object from the context menu. The connection object will be highlighted in the tree. In order to find other connection objects that share the same geometry pair, right-click on the highlighted object and choose the Go To Connections for Duplicate Pairs from the context menu; all connection objects that share the same geometry pair will be highlighted. To search for connection objects that share the same geometry pair manually for one or more connection objects, select Search Connections for Duplicate Pairs from the context menu of these connection objects (by highlighting these connection objects first). If this command is issued from a Connection Group folder, the search will be carried out for all connection objects under this folder. When this command is issued from the Connections folder, the search will be for the entire connection objects under this folder.

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Contact

Moving and Copying Connection Objects To move a connection object to another folder of the same connection type, drag the object and drop it on that folder. For example, to move a contact region object, drag the object from its current Contacts folder and drop it on another folder whose Connection Type is Contact (possibly named Contacts 2). To copy a connection object to another folder of the same connection type, hold the Ctrl key while performing the move procedure described above.

Treatment of Legacy Databases Supported connection objects from databases of previous versions of ANSYS Workbench will be grouped based on their types and migrated into Connection Group folders.

Contact The following topics are covered in this section: Contact Overview Contact Formulation Theory Contact Settings Supported Contact Types Setting Contact Conditions Manually Contact Ease of Use Features Contact in Rigid Dynamics Best Practices for Specifying Contact Conditions

Contact Overview Contact conditions are created when an assembly is imported into the application and it detects that two separate bodies (solid, surface, and line bodies) touch one another (they are mutually tangent). Bodies/surfaces in contact: • Do not “interpenetrate.” • Can transmit compressive normal forces and tangential friction forces. • Can be bonded together (Linear) • Able to separate and collide (Nonlinear) Surfaces that are free to separate and move away from one another are said to have changing-status nonlinearity. That is, the stiffness of the system depends on the contact status, whether parts are touching or separated. Use the Contact Tool to help you coordinate contact conditions before loading and as part of the final solution.

Note For information about controlling the quality of facets, see Facet Quality in the Graphics section of the ANSYS DesignModeler help.

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Contact Formulation Theory Contact solutions are often very complicated. It is recommended that, whenever possible, that user employ the Program Controlled settings. However, in order to better understand your selections, this section examines the specifics of Formulations. Because physical contacting bodies do not interpenetrate, the application must establish a relationship between the two surfaces to prevent them from passing through each other in the analysis. When the application prevents interpenetration, it is said to enforce “contact compatibility”.

In order to enforce compatibility at the contact interface, Workbench Mechanical offers several different contact Formulations. These Formulations define the solution method used. Formulations include the following and are discussed in detail in the Formulations section. • Pure Penalty (Default — Program Controlled) • Augmented Lagrange • MPC • Normal Lagrange For nonlinear solid body contact of faces, Pure Penalty or Augmented Lagrange formulations can be used. Both of these are penalty-based contact formulations: FNormal = kNormalxPenetration The finite contact Force, Fn, is a concept of contact stiffness, kNormal. The higher the contact stiffness, the lower the penetration, xp, as illustrated here.

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Contact Ideally, for an infinite kNormal, one would get zero penetration. This is not numerically possible with penalty-based methods, but as long as xp is small or negligible, the solution results are accurate. The main difference between Pure Penalty and Augmented Lagrange methods is that Augmented Lagrange augments the contact force (pressure) calculations: Pure Penalty: FNormal = kNormalxPenetration Augmented Lagrange: FNormal = kNormalxPenetration + λ Because of the extra term λ, the Augmented Lagrange method is less sensitive to the magnitude of the contact stiffness kNormal. Another available option is Normal Lagrange. This formulation adds an extra degree of freedom (contact pressure) to satisfy contact compatibility. Consequently, instead of resolving contact force as contact stiffness and penetration, contact force (contact pressure) is solved for explicitly as an extra DOF. FNormal = DOF Specifications: • Enforces zero/nearly zero penetration with pressure DOF. • Does not require a normal contact stiffness (zero elastic slip) • Requires Direct Solver, which can increase computation requirements. Normal Lagrange Chattering Chattering is an issue which often occurs with Normal Lagrange method. If no penetration is allowed (left), then the contact status is either open or closed (a step function). This can sometimes make convergence more difficult because contact points may oscillate between open/closed status and is called «chattering». If some slight penetration is allowed (right), it can make it easier to converge since contact is no longer a step change.

For the specific case of Bonded and No Separation Types of contact between two faces, a Multi-Point constraint (MPC) formulation is available. MPC internally adds constraint equations to “tie” the displacements between contacting surfaces. This approach is not penalty-based or Lagrange multiplier-based. It is a direct, efficient way of relating surfaces of contact regions which are bonded. Large-deformation effects are supported with MPC-based Bonded contact.

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Comparison of Formulations Some of the primary aspects of contact formulations are compared below. Pure Penalty

Augmented Lagrange

Normal Lagrange

Good convergence beha- Additional equilibrium iter- Additional equilibrium vior (few equilibrium iter- ations needed if penetraiterations if needed ations). tion is too large. chattering is present. Sensitive to selection of normal contact stiffness.

Less sensitive to selection of normal contact stiffness.

Contact penetration is present and uncontrolled.

Contact penetration is present but controlled to some degree.

Good convergence behavior (few equilibrium iterations).

No normal contact stiffness is required. Usually, penetration is near-zero.

No Penetration. Only Bonded & No Separation behaviors.

Useful for any type of contact behavior. Iterative or Direct Solvers can be used.

MPC

Only Direct Solver can be Used.

Iterative or Direct Solvers can be used.

Symmetric or Asymmetric contact available.

Asymmetric contact Only

Contact detection at integration points.

Contact Detection at Nodes.

Contact Settings When a model is imported into Workbench Mechanical, the default setting of the application automatically detects instances where two bodies are in contact and generates corresponding Contact Region objects in the Tree Outline. When a Contact Region is selected in the Tree Outline, as illustrated here, contact settings are available in the Details view, and are included in the following categories: • Scope: settings for displaying, selecting, or listing contact and target geometries. • Definition: commonly used contact settings. • Advanced: advanced controls that are primarily program controlled. • Geometric Modification: settings for further defining contact interface behaviors.

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Contact

Scope Settings The properties for the Scope category are described in the following table. Property

Description/Selections

Scoping Method

Specifies whether the Contact Region is applied to a Geometry Selection (default), a Named Selection, or to a Pre-Generated Interface for fracture mechanics (Interface Delamination) when you are using the ANSYS Composite PrepPost (ACP) application.

Interface

This property displays when you select Pre-Generated Interface as the Scoping Method. It provides a drop-down list of the available interface layers that were imported from ACP.

Contact

Displays/selects which geometries (faces, edges, or vertices) are considered as contact. The geometries can be manually selected or automatically generated. For a Face/Edge contact, the edge must be designated as Contact. A contact pair can have a flexible-rigid scoping, but the flexible side of the pair must always be the Contact side. If the Contact side of the contact pair is scoped to multiple bodies, all of the bodies must have the same Stiffness Behavior, either Rigid or Flexible.

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Description/Selections Note that if you click on this field, the bodies are highlighted.

Target

Displays which body element (face or edge) is considered Target (versus Contact). This element can be manually set or automatically generated. For Face/Edge contact, the face must be designated as Target. If the Contact side of the contact pair has a flexible Stiffness Behavior then the Target side can be rigid. Multiple rigid bodies cannot be selected for the Target side scoping of the contact pair. The selection of multiple rigid bodies for the Target invalidates the Contact Region object and an error message is generated following the solution process. Note that if you click on this field, the bodies are highlighted.

Contact Bodies

This read only property displays which bodies have faces or edges in the Contact list.

Target Bodies

This read only property displays which bodies have faces or edges in the Target list.

Contact Shell Face

Specifies whether the Contact should be applied on a surface body’s top face or bottom face. If you set Contact Shell Face to the default option, Program Controlled, then the Target Shell Face option must also be set to Program Controlled. The Program Controlled default option is not valid for nonlinear contact types. This option displays only when you scope a surface body to Contact Bodies.

Target Shell Face

Specifies whether the Target should be applied on a surface body’s top face or bottom face. If you set Target Shell Face to the default option, Program Controlled, then the Contact Shell Face option must also be set to Program Controlled. The Program Controlled default option is not valid for nonlinear contact types. This option displays only when you scope a surface body to Target Bodies.

Shell Thickness Effect (See Using KEYOPT(11))

This property appears when the scoping of the contact or target includes a surface body. Options include: • Yes — indicates to include the property. • No (default) — indicates to exclude the property. When set to Yes, the contact object becomes under-defined if the Offset Type of any scoped surface body is set to a value other than Middle, In this situation, the following error message will be displayed: «The shell thickness effect of a contact pair is turned on; however, the offset type of a shell body in contact is set to other than Middle. Please set its offset type to Middle.» In the presence of a Thickness, Imported Thickness, Layered Section, or an Imported Layered Section object, the following warning message will be issued if a solve is requested: «The shell thickness effect of a contact pair is turned on. Please make sure that the offset

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Contact Property

Description/Selections type of the thickness, imported thickness, layered sections and imported layered sections objects associated with the shell bodies in contact are set to Middle.»

Shell Thickness Effect The Shell Thickness Effect allows users to automatically include the thickness of the surface body during contact calculations. Instead of contact being detected on the face of the surface body, contact will be detected a distance of half the thickness away from the face. If the surface body undergoes large strains and changes thickness, the updated (current) thickness is also used in the contact calculations. However, to be able to take advantage of this feature, the Offset Type must be set to Middle. For cases where the user has set Offset Type to Top or Bottom, the user can do the following: • For a given contact region, if contact is occurring on the same face (Top or Bottom) as the offset, no special settings are required. The location of the nodes and elements of the surface body represent the actual position of that face. • For Rough, Frictionless, or Frictional contact types, if contact is occurring on the opposite face as the offset, specify a contact Offset equal to the shell thickness for the Interface Treatment. Note that changes in shell thickness for large strain analyses will not be considered.

Note If the Shell Thickness Effect is activated and the user has specified a contact Offset for the Interface Treatment, the total offset will be half the thickness of the surface body plus the defined contact offset. Postprocessing surface bodies with the shell thickness effect has the following special considerations: • Because contact is detected half of the thickness from the middle of the surface body, viewing surface body results without Thick Shell and Beam (See Main Menu>View Menu) effects turned on will show an apparent gap between contact bodies. This is normal since contact is being detected away from the location of the nodes and elements. • When using the Contact Tool to postprocess penetration or gaps, these values are measured from the middle of the surface bodies (location of the nodes and elements), regardless of whether or not the shell thickness effect is active.

Support Specifications Note • All bodies selected for the Target or Contact side of a contact pair must have the same stiffness behavior. • You cannot scope the target side in a contact pair to more than one rigid body.

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Setting Connections • If any of the bodies you scope have rigid stiffness behavior, you must select Asymmetric behavior under Definition in the Details view. • If you have both rigid and flexible bodies in your contact pair, you must scope the rigid body as a Target.

Definition Settings The differences in the contact settings determine how the contacting bodies can move relative to one another. This category provides the following properties. • Type • Scope Mode • Behavior • Trim Contact • Suppressed

Type Choosing the appropriate contact type depends on the type of problem you are trying to solve. If modeling the ability of bodies to separate or open slightly is important and/or obtaining the stresses very near a contact interface is important, consider using one of the nonlinear contact types (Frictionless, Rough, Frictional), which can model gaps and more accurately model the true area of contact. However, using these contact types usually results in longer solution times and can have possible convergence problems due to the contact nonlinearity. If convergence problems arise or if determining the exact area of contact is critical, consider using a finer mesh (using the Sizing control) on the contact faces or edges. The available contact types are listed below. Most of the types apply to Contact Regions made up of faces only.

• Bonded: This is the default configuration and applies to all contact regions (surfaces, solids, lines, faces, edges). If contact regions are bonded, then no sliding or separation between faces or edges is allowed. Think of the region as glued. This type of contact allows for a linear solution since the contact length/area will not change during the application of the load. If contact is determined on the mathematical model, any gaps will be closed and any initial penetration will be ignored. [Not supported for Rigid Dynamics. Fixed joint can be used instead.]

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Contact • No Separation: This contact setting is similar to the Bonded case. It only applies to regions of faces (for 3D solids) or edges (for 2D plates). Separation of the geometries in contact is not allowed. • Frictionless: This setting models standard unilateral contact; that is, normal pressure equals zero if separation occurs. Thus gaps can form in the model between bodies depending on the loading. This solution is nonlinear because the area of contact may change as the load is applied. A zero coefficient of friction is assumed, thus allowing free sliding. The model should be well constrained when using this contact setting. Weak springs are added to the assembly to help stabilize the model in order to achieve a reasonable solution. • Rough: Similar to the frictionless setting, this setting models perfectly rough frictional contact where there is no sliding. It only applies to regions of faces (for 3D solids) or edges (for 2D plates). By default, no automatic closing of gaps is performed. This case corresponds to an infinite friction coefficient between the contacting bodies. [Not supported for Explicit Dynamics analyses.] • Frictional: In this setting, the two contacting geometries can carry shear stresses up to a certain magnitude across their interface before they start sliding relative to each other. This state is known as «sticking.» The model defines an equivalent shear stress at which sliding on the geometry begins as a fraction of the contact pressure. Once the shear stress is exceeded, the two geometries will slide relative to each other. The coefficient of friction can be any nonnegative value. [Not supported for Rigid Dynamics. Forced Frictional Sliding should be used instead.] • Forced Frictional Sliding: In this setting, a tangent resisting force is applied at each contact point. The tangent force is proportional to the normal contact force. This settings is similar to Frictional except that there is no «sticking» state. [Supported only for Rigid Dynamics] By default the friction is not applied during collision. Collisions are treated as if the contact is frictionless regardless the friction coefficient. The following commands override this behavior and include friction in shock resolution (see Rigid Dynamics Command Objects Library in the ANSYS Mechanical User’s Guide for more information). options=CS_SolverOptions() options.FrictionForShock=1 Note that shock resolution assumes permanent sliding during shock, which may lead to unrealistic results when the friction coefficient is greater than 0.5. • Friction Coefficient: Allows you to enter a friction coefficient. Displayed only for frictional contact applications.

Note • For the Bonded and No Separation contact Type, you can simulate the separation of a Contact Region as it reaches some predefined opening criteria using the Contact Debonding feature. • Refer to KEYOPT(12) in the Mechanical APDL Contact Technology Guide for more information about modelling different contact surface behaviors.

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Scope Mode This is a read-only property that displays how the selected Contact Region was generated. Either automatically generated by the application (Automatic) or constructed or modified by the user (Manual). Note that this property is not supported for Rigid Body Dynamics analyses.

Behavior This property will appear only for 3D Face/Face or 2D Edge/Edge contacts. For 3D Edge/Edge or Face/Edge contacts, internally the program will set the contact behavior to Asymmetric (see below). Note that this property is not supported for Rigid Body Dynamics analyses.

Sets contact pair to one of the following: • Program Controlled (Default for the Mechanical APDL solver): internally the contact behavior is set to the following options based on the stated condition: – Auto Asymmetric (see below) — for Flexible-Flexible bodies. – Asymmetric (see below) — for Flexible-Rigid bodies. For Rigid-Rigid contacts, the Behavior property is under-defined for the Program Controlled setting. The validation check is performed at the Contact object level when all environment branches are using the Mechanical APDL solver. If the solver target for one of the environments is other than Mechanical APDL, then this validation check will be carried out at the environment level; the environment branch will become under-defined. • Asymmetric: Contact will be asymmetric for the solve. All face/edge and edge/edge contacts will be asymmetric. [Not supported for Explicit Dynamics analyses.] Asymmetric contact has one face as Contact and one face as Target (as defined under Scope Settings), creating a single contact pair. This is sometimes called «one-pass contact,» and is usually the most efficient way to model face-to-face contact for solid bodies. The Behavior must be Asymmetric if the scoping includes a body specified with rigid Stiffness Behavior. • Symmetric: Contact will be symmetric for the solve. • Auto Asymmetric: Automatically creates an asymmetric (p. 512) contact pair, if possible. This can significantly improve performance in some instances. When you choose this setting, during the solution phase the

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Contact solver will automatically choose the more appropriate contact face designation. Of course, you can designate the roles of each face in the contact pair manually. [Not supported for Explicit Dynamics analyses.]

Note Refer to KEYOPT(8) in the Mechanical APDL Contact Technology Guide for more information about asymmetric contact selection.

Trim Contact The Trim Contact feature can speed up the solution time by reducing the number of contact elements sent to the solver for consideration. Note that this feature is not supported for Rigid Body Dynamics analyses.

Trim Contact options include: • Program Controlled: This is the default setting. The application chooses the appropriate setting. Typically, the program sets Trim Contact to On. However, if there are manually created contact conditions, no trimming is performed. • On: During the process of creating the solver input file, checking is performed to determine the proximity between source and target elements. Elements from the source and target sides which are not in close proximity (determined by a tolerance) are not written to the file and therefore ignored in the analysis. • Off: No contact trimming is performed. The checking process is performed to identify if there is overlap between the bounding boxes of the elements involved. If the bounding box of an element does not overlap the bounding box of an opposing face or element set, that element is excluded from the solution. Before the elements are checked, the bounding boxes are expanded using the Trim Tolerance property (explained below) so that overlapping can be detected. Trim Tolerance This property provides the ability to define the tolerance value that is used to expand the bounding boxes of the elements before the trimming process is performed. This property is available for both automatic and manual contacts when the Trim Contact is set to On. It is only available for automatic contacts when the Trim Contact is set to Program Controlled since no trimming is performed for manual contacts. For automatic contacts, this property displays the value that was used for contact detection and it is a read-only field. For manual contacts, enter a value greater than zero.

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Setting Connections Note that a doubling expansion effect can result from the bounding box expansion since the bounding box of both the source and target elements are expanded. An example of the double expansion effect is illustrated below where the Trim Tolerance is defined as 10 mm. For simplicity sake, the size of the elements is specified as 5mm. Therefore, the bounding boxes for the contact/target elements will extend 10mm (two elements) in each direction as represented by the orange boxes, solid and dashed. For each face, Contact and Target, the number of elements that will be used are illustrated.

The brown area illustrated below represents the elements from the contact face. On the corresponding target side exist potential elements from the entire target face. The elements of the target face that will be kept are drawn in black. On the target Face, each element bounding box is expanded by 10mm and an overlap is sought against each element from the contact side. Referring to the image below, the bounding boxes between Contact Element 1 (CE1) and Target Element 2 (TE2) overlap thus TE2 is included in the analysis. Meanwhile, CE3 and TE4 do not overlap and as a result, TE4 is not included in the analysis. This results in a reduced number of elements in the analysis and, typically, a faster solution.

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Contact

Suppressed Specifies whether or not the Contact Region is included in the solution.

Advanced Settings The Advanced category provides the following properties. • Formulation • Detection Method • Penetration Tolerance • Elastic Slip Tolerance • Normal Stiffness • Constraint Type • Update Stiffness • Stabilization Damping Factor • Thermal Conductance • Pinball Region

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Setting Connections • Pinball Radius • Electric Conductance • Restitution Factor — Rigid Body Dynamics Solver Only

Formulation Formulation options allow you to specify which algorithm the software uses for a particular Contact pair computation. Property options include:

Property

Description

Program Controlled

This is the default setting. For this setting, the application selects the Pure Penalty property for contact between two rigid bodies and the Augmented Lagrange property for all other contact situations.

Pure Penalty

Basic contact formulation based on Penalty method.

Augmented Lagrange

Also a penalty-based method. Compared to the Pure Penalty method, this method usually leads to better conditioning and is less sensitive KEYto the magnitude of the contact stiffness coefficient. However, in OPT(2) some analyses, the Augmented Lagrange method may require addi=0 tional iterations, especially if the deformed mesh becomes too distorted.

MPC

Available for Bonded and for No Separation contact Types. Multipoint Constraint equations are created internally during the Mechanical APDL application solve to tie the bodies together. This can be helpful if truly linear contact is desired or to handle the nonzero mode issue for free vibration that can occur if a penalty function is used. Note that contact based results (such as pressure) will be zero.

Note When modeling Shell-Solid assemblies with the MPC contact Formulation, the contact surface/edge must be on the shell side and the target surface must be on the solid side. However, you can override this requirement to support certain special cases, such as acoustics. Please see the Modeling a Shell-Solid As-

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MAPDL KEYOPT(2) =1

KEYOPT(2) =2

Contact sembly section of the Mechanical APDL Contact Technology Guide for additional information. Normal Lagrange

Enforces zero penetration when contact is closed making use of a Lagrange multiplier on the normal direction and a penalty method in the tangential direction. Normal Stiffness is not applicable for this KEYsetting. Normal Lagrange adds contact traction to the model as addiOPT(2) tional degrees of freedom and requires additional iterations to stabilize =3 contact conditions. It often increases the computational cost compared to the Augmented Lagrange setting. The Iterative setting (under Solver Type) cannot be used with this method.

For additional MAPDL specific information, see KEYOPT(2) in the Mechanical APDL Contact Technology Guide.

Note Cases involving large gaps and faces bonded together can result in fictitious moments being transmitted across a boundary.

Detection Method Detection Method allows you to choose the location of contact detection used in the analysis in order to obtain a good convergence. It is applicable to 3D face-face contacts and 2D edge-edge contacts. Property options include:

Property

Description

Program Controlled

This is the default setting. The application uses Gauss integration points (On Gauss Point) when the formulation is set to Pure Penalty and Augmented Lagrange. It uses nodal point (Nodal-Normal to Target) for MPC and Normal Lagrange formulations.

On Gauss Point

The contact detection location is at the Gauss integration points. This option is not applicable to contacts with MPC or Normal Lagrange formulation.

Nodal — Normal From Contact

The contact detection location is on a nodal point where the contact normal is perpendicular to the contact surface.

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Setting Connections Nodal — Normal To Target

The contact detection location is on a nodal point where the contact normal is perpendicular to the target surface.

Nodal — Projected Normal From Contact

The contact detection location is at contact nodal points in an overlapping region of the contact and target surfaces (projection-based method).

For additional MAPDL specific information, see Selecting Location of Contact Detection (specifically, KEYOPT(4) related information) in the Mechanical APDL Contact Technology Guide.

Penetration Tolerance The Penetration Tolerance property allows you to specify the Penetration Tolerance Value or the Penetration Tolerance Factor for a contact when the Formulation property is set to Program Controlled, Pure Penalty, or Augmented Lagrange.

Note The Update Stiffness property must be set to either Program Controlled, Each Iteration, or Each Iteration, Aggressive for the Penetration Tolerance property to be displayed when Formulation is set to Pure Penalty. Property options include:

Property

Description

Program Controlled

This is the default setting. The Penetration Tolerance is calculated by the program.

Value

Enter the Penetration Tolerance Value directly. This entry is a length measurement (foot, meter, etc.). Only non-zero positive values are valid.

Factor

Enter the Penetration Tolerance Factor directly. This entry must be equal to or greater than zero but must also be less than 1.0. This entry has no unit.

Penetration Tolerance Value The Penetration Tolerance Value property displays when Penetration Tolerance is set to Value. You enter a Value. Penetration Tolerance Factor

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Contact The Penetration Tolerance Factor property displays when Penetration Tolerance is set to Factor. You enter a Factor.

Note When viewing the Connections Worksheet, a Value displays as a negative number and a Factor displays as a positive number. For additional information, see the Determining Contact Stiffness and Allowable Penetration, specifically Using FKN and FTOLN, section of the Mechanical APDL Contact Technology Guide (Surface-to-Surface Contact).

Elastic Slip Tolerance The Elastic Slip Tolerance property allows you to set the allowable elastic slip value for a contact when the Formulation is set to Normal Lagrange or when the contact stiffness is set to update each iteration (Update Stiffness is set to Each Iteration or Each Iteration, Aggressive).

Note Elastic Slip Tolerance is not applicable when the contact Type is set to Frictionless or No Separation. Property options include:

Property

Description

Program Controlled

This is the default setting. The Elastic Slip Tolerance Value is calculated by the application.

Value

Enter the Elastic Slip Tolerance Value directly. This entry is a length measurement (foot, meter, etc.). Only non-zero positive values are valid.

Factor

Enter the Elastic Slip Tolerance Factor directly. This entry must be equal to or greater than zero but must also be less than 1.0. This entry has no unit.

Elastic Slip Tolerance Value The Elastic Slip Tolerance Value property displays when Elastic Slip Tolerance is set to Value. You enter a Value. Elastic Slip Tolerance Factor Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Connections The Elastic Slip Tolerance Factor property displays when Elastic Slip Tolerance is set to Factor. You enter a Factor.

Note When viewing the Connections Worksheet, a Value displays as a negative number and a Factor displays as a positive number. For additional information, see the Determining Contact Stiffness and Allowable Penetration, specifically Using FKT and SLTO, section of the Mechanical APDL Contact Technology Guide (Surface-to-Surface Contact).

Constraint Type Controls the type of MPC constraint to be created for bonded contact. This setting is displayed only if Formulation is set to MPC and if either Contact Bodies or Target Bodies are scoped to a surface body. Property options include:

Property

Description

Target Normal, Couple U to ROT

This is the default setting. Represents the most common type of surface body contact. Constraints are constructed to couple the translational and rotational DOFs. In most types of surface body contact, an offset will exist. Due to this offset there will be a moment created. To get the correct moment, the rotation/displacement DOF’s must be coupled together. If the program cannot detect any contact in the target normal direction, it will then search anywhere inside the pinball for contact.

Target Normal, Uncouple U to ROT

The rotational and displacement constraints will not be coupled together. This option can model situations where the surface body edges line up well and a moment is not created from the physical surface body positions. Thus it is most accurate for the constraints to leave the displacements/rotations uncoupled. This provides an answer which is closer to a matching mesh solution. Using a coupled constraint causes artificial constraints to be added causing an inaccurate solution.

Inside Pinball, Couple U to ROT

Constraints are coupled and created anywhere to be found inside the pinball region. Thus the pinball size is important as a larger pinball will result in a larger constraint set. This option is useful when you wish to fully constrain one contact side completely to another.

Normal Stiffness Defines a contact Normal Stiffness factor. Property options include:

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Contact Option

Description

Program Controlled

This is the default setting. The Normal Stiffness Factor is calculated by the program. If only Bonded or No Separation contact exists, the value is set to 10. If any other type of contact exists, all the program controlled regions (including Bonded or No Separation) will use the Mechanical APDL application default (Real Constant FKN).

Manual

The Normal Stiffness Factor is input directly by the user.

Normal Stiffness Factor This property appears when the Normal Stiffness is set to Manual. It allows you to input the Normal Stiffness Factor. Only non-zero positive values are allowed. The usual factor range is from 0.01-10, with the default selected programmatically. A smaller value provides for easier convergence but with more penetration. The default value is appropriate for bulk deformation. If bending deformation dominates, use a smaller value (0.01-0.1). For additional MAPDL specific information, see the • Determining Contact Stiffness and Allowable Penetration section of the Mechanical APDL Contact Technology Guide (Surface-to-Surface Contact). • Using FKN and FTOLN section of the Mechanical APDL Contact Technology Guide (Surface-to-Surface Contact).

Update Stiffness Allows you to specify if the program should update (change) the contact stiffness during the solution. If you choose any of these stiffness update settings, the program will modify the stiffness (raise/lower/leave unchanged) based on the physics of the model (that is, the underlying element stress and penetration). This choice is displayed only if you set the Formulation to Augmented Lagrange or Pure Penalty, the two formulations where contact stiffness is applicable. An advantage of choosing either of the program stiffness update settings is that stiffness is automatically determined that allows both convergence and minimal penetration. Also, if this setting is used, problems may converge in a Newton-Raphson sense, that would not otherwise. You can use a Result Tracker to monitor a changing contact stiffness throughout the solution. Property options include:

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Setting Connections Property

Description

Program Controlled

(Default as set in Tools->Options). Internally set based on the following criteria: if the Interface Treatment property is available and it is set to Add Offset, Ramped Effects, the update stiffness property should be set to Never; otherwise, set the update stiffness property to Never for contacts between two rigid bodies and to Each Iteration for others.

Never

This is the default setting. Turns off the program’s automatic Update Stiffness feature.

Each Iteration

Sets the program to update stiffness at the end of each equilibrium iteration. This choice is recommended if you are unsure of a Normal Stiffness Factor to use in order to obtain good results.

Each Iteration, Aggressive

Sets the program to update stiffness at the end of each equilibrium iteration, but compared to the Each Iteration, this option allows for a more aggressive changing of the value range.

Stabilization Damping Factor A contact you define may initially have a near open status due to small gaps between the element meshes or between the integration points of the contact and target elements. The contact will not get detected during the analysis and can cause a rigid body motion of the bodies defined in the contact. The stabilization damping factor provides a certain resistance to damp the relative motion between the contacting surfaces and prevents rigid body motion. This contact damping factor is applied in the contact normal direction and it is valid only for frictionless, rough and frictional contacts. The damping is applied to each load step where the contact status is open. The value of the stabilization damping factor should be large enough to prevent rigid body motion but small enough to ensure a solution. A value of 1 is usually appropriate. Property options include: Property Stabilization Damping Factor

Description

MAPDL

If this factor is 0 (default), the damping is activated only in the first load step (KEYOPT(15) = 0, the default). If its value is greater than 0, the damping is activated for all load steps (KEYOPT(15) = 2).

FDMN

Damping is activated for all load steps.

Thermal Conductance Controls the thermal contact conductance value used in a thermal contact simulation. Property options include: Property

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KEYOPT(15) = 2.

Description

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Contact Program Controlled

This is the default setting. The program will calculate the value for the thermal contact conductance. The value will be set to a sufficiently high enough value (based on the thermal conductivities and the model size) to model perfect contact with minimal thermal resistance.

Manual

The Thermal Conductance Value is input directly by the user.

Thermal Conductance Value Allows input of the Thermal Conductance Value. Only positive values are allowed. This choice is displayed only if Manual is specified for Thermal Conductance. The Units for this value are based on the types of contact involved. For 3D faces and 2D edges, the units are HEAT/(TIME * TEMPERATURE* AREA). For contact between 3D edges and vertices, the units are HEAT/(TIME * TEMPERATURE) with the value applied to every node in the contact side. For more information about the units used for thermal contact conductance coefficient, see Table 78 and Table 79 in the Solving Units section. For additional MAPDL specific information, see the Modeling Thermal Contact, specifically Modeling Conduction>Using TCC, section of the Mechanical APDL Contact Technology Guide (Multiphysics Contact).

Pinball Region This option allows you to specify the contact search size, commonly referred to as the Pinball Region. Setting a pinball region can be useful in cases where initially, bodies are far enough away from one another that, by default, the program will not detect that they are in contact. You could then increase the pinball region as needed. Consider an example of a surface body that was generated by offsetting a face of a solid body, possibly leaving a large gap, depending on the thickness. Another example is a large deflection problem where a considerable pinball region is required due to possible large amounts of over penetration. In general though, if you want two regions to be bonded together that may be far apart, you should specify a pinball region that is large enough to ensure that contact indeed occurs. For bonded and no separation contact types, you must be careful in specifying a large pinball region. For these types of contact, any regions found within the pinball region will be considered to be in contact. For other types of contact, this is not as critical because additional calculations are performed to determine if the two bodies are truly in contact. The pinball region defines the searching range where these calculations will occur. Further, a large gap can transmit fictitious moments across the boundary. Property options include: Property

Description

Program Controlled

This is the default setting. The pinball region will be calculated by the program.

Auto Detection Value

This option is only available for contacts generated automatically. The pinball region will be equal to the tolerance value used in generating the contacts. The value is displayed as read-only in the Auto Detection Value field. Auto Detection Value is the recommended option for cases where the automatic contact detection region is larger than a Program Controlled region. In such cases, some contact pairs that were detected automatically may not be considered in contact for a solution.

Radius

The radius value is input directly by the user.

For the Rigid Body Dynamics solver: In the Rigid Body Dynamics solver, the pinball region is used to control the touching tolerance. By default, the Rigid Body Dynamics solver automatically computes the touching tolerance using the sizes of the surfaces in the contact region. These default values are sufficient in most of cases, but inadequate touching tolerance may arise in cases where contact surfaces Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Connections are especially large or small (small fillet for instance). In such cases, the value of the touching tolerance can be directly specified using the following properties: Property

Description

Program Controlled (default)

The touching tolerance is automatically computed by the Rigid Body Dynamics solver from the sizes of the contact surfaces.

Radius

The value of the touching tolerance is directly given by user.

Pinball Radius The numerical value for the Pinball Radius. This choice is displayed only if Pinball Region is set to Radius.

Electric Conductance Controls the electric contact conductance value used in an electric contact simulation. Property options include: Property

Description

Program Controlled

This is the default setting. The program will calculate the value for the electric contact conductance. The value will be set to a sufficiently high enough value (based on the electric conductivities and the model size) to model perfect contact with minimal electric resistance.

Manual

The Electric Conductance Value is input directly by the user.

Note The Electric Analysis result, Joule Heat, when generated by nonzero contact resistance is not supported.

Electric Conductance Value Allows input of the Electric Conductance Value (in units of electric conductance per area). Only positive values are allowed. This choice is displayed only if Manual is specified for Electric Conductance.

Time Step Controls Allows you to specify if changes in contact behavior should control automatic time stepping. This choice is displayed only for nonlinear contact (Type is set to Frictionless, Rough, or Frictional). Property options include: Property

Description

None

This is the default setting. Contact behavior does not control automatic time stepping. This option is appropriate for most analyses when automatic time stepping is activated and a small time step size is allowed.

Automatic Bisection

Contact behavior is reviewed at the end of each substep to determine whether excessive penetration or drastic changes in contact status have occurred. If so,

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Contact the substep is reevaluated using a time increment that is bisected (reduced by half ). Predict for Impact

Performs same bisection on the basis of contact as the Automatic Bisection option and also predicts the minimal time increment needed to detect changes in contact behavior. This option is recommended if you anticipate impact in the analysis.

Restitution Factor — Rigid Body Dynamics Solver Only For the ANSYS Rigid Dynamics solver, the Advanced group has only one property, Restitution Value. This value represents the energy lost during shock and is defined as the ratio between relative velocity prior to the shock and the velocity following the shock. This value can be between 0 and 1. A Restitution Factor equal to 1 indicates that no energy is lost during the shock, that is, the rebounding velocity equals the impact velocity (a perfectly elastic collision). The default value is 1.

Geometric Modification The Geometric Modification category provides the properties described below. As described, this category only displays when certain contact conditions are detected by the application and/or certain property definitions are specified.

Interface Treatment The Interface Treatment property defines how the contact interface of a contact pair is treated. It becomes active when contact Type is set to Frictionless, Rough or Frictional (nonlinear contact). When active, the Interface Treatment option provides the following properties.

• Adjust to Touch: Any initial gaps are closed and any initial penetration is ignored creating an initial stress free state. Contact pairs are “just touching” as shown.

Contact pair before any Interface Treatment. Gap exists.

Contact pair after Adjust to Touch treatment. Gap is closed automatically. Pair is “just touching”.

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Setting Connections

Contact pair before any Interface Treatment. Penetration exists.

Contact pair after Adjust to Touch treatment. Pair touches at interface.

This setting is useful to make sure initial contact occurs even if any gaps are present (as long as they are within the pinball region). Without using this setting, the bodies may fly apart if any initial gaps exist. Although any initial gaps are ignored, gaps can still form during loading for the nonlinear contact types. For nonlinear contact types (Frictionless, Rough, and Frictional), Interface Treatment is displayed where the choices are Adjust to Touch, Add Offset, Ramped Effects, and Add Offset, No Ramping. • Add Offset, Ramped Effects: models the true contact gap/penetration plus adds in any user defined offset values. This setting is the closest to the default contact setting used in the Mechanical APDL application except that the loading is ramped. Using this setting will not close gaps. Even a slight gap may cause bodies to fly apart. Should this occur, use a small contact offset to bring the bodies into initial contact. Note that this setting is displayed only for nonlinear contact. • Add Offset, No Ramping: this is the default setting. This option is the same as Add Offset, Ramped Effects but loading is not ramped. • Offset: appears if Interface Treatment is set to Add Offset, Ramped or Add Offset, No Ramping. This property defines the contact offset value. A positive value moves the contact closer together (increase penetration/reduce gap) and a negative value moves the contact further apart.

Contact pair before any Interface Treatment. Gap exists.

Contact pair after Add Offset treatment (either option). Gap is closed «manually” based on value entered for Offset (positive value shown that includes some penetration).

Contact Geometry Correction When specified as Bolt Thread (the default is None), the Contact Geometry Correction property activates the properties shown below.

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Contact For 2D axisymmetric models, only edge-to-edge scoping is supported and for 3D models, only face-toface scoping is supported. For additional information about this property, please see the Simplified Bolt Thread Modeling section of the Mechanical APDL Contact Technology Guide.

Tip When you specify the Bolt Thread option, it is strongly recommended that you have a refined mesh. Please see the Relevance and the Sizing Group (Category) sections of the Meshing User’s Guide for additional information about mesh refinement. Support Requirements In order to use the Bolt Thread option, please note the following. • The Contact Geometry Correction property is available for all contact Type settings except for Bonded. • The Behavior properties Symmetric and Auto-Asymmetric are not supported. • It is recommended that you do not set the Detection Method to either Nodal-Normal To Target or On Gauss Point.

Bolt Thread Property The following properties are visible when Contact Geometry Correction is set to Bolt Thread. Orientation Property options include: • Program Controlled (default): A contact condition with Contact Geometry Correction defined as Bolt Thread, is fully defined only when cylindrical contact conditions are detected by the application, otherwise, manual specifications are required. • Revolute Axis: when Revolute Axis is selected, the following additional properties display. These properties define the coordinate systems that are used to generate the axis around which the bolt is oriented. They do not correspond to the starting and ending point of the bolt threads. – Starting Point – Ending Point

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Setting Connections Mean Pitch Diameter This property defines the average diameter of the threaded bolt. Pitch Distance This property defines the length of the thread pitch. Thread Angle This property defines the angle of the thread’s inclination. The following diagram illustrates the Mean Pitch Diameter, Pitch Distance, and Thread Angle.

Thread Type This property defines the number of threads on the bolt. Property options include: • Single-Thread • Double-Thread • Triple-Thread Handedness This property defines the bolt as either right or left handed. Property options include: • Right-Handed • Left-Handed

Supported Contact Types The following table identifies the supported formulations and whether symmetry is respected for the various contact geometries. Contact Geometry

Face

Edge

(Scope = Contact)

(Scope = Contact)

Vertex (Line Bodies Only) (Scope = Contact)

Face (Scope = Target)

Symmetry Respected: Yes

Edge[1] (p. 529) Not Supported for solving.

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Symmetry Respected: No

Symmetry Respected: No

Symmetry Respected: No

Symmetry Respected: No

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Contact (Scope = Target) Vertex (Scope = Target)

Not Supported for solving.

Not Supported for solving.

Not Supported for solving.

[1]: The underlying body cannot be a line body. In 2D analyses, only edge-edge contact is supported (the equivalent of 3D face-face contact).

Setting Contact Conditions Manually Manual contact regions represent contact over the entire extent of the contact scope, for example, faces of the contact region. Automatic contact regions represent contact only to the extent of the scope where the corresponding bodies initially are close to one another. For automatic contact, the contact elements are “trimmed” before solution. The trimming is based on the detection tolerance. The tighter the tolerance, the less number of generated contact elements. Note that if you set Large Deflection effects to On in the Details view of a Solution object, no trimming will be done due to the possibility of large sliding. Valid reasons to manually change or add/delete contact regions include: • Modeling «large sliding» contact. Contact regions created through auto-detection assume «assembly contact,» placing contact faces very near to one another. Manual contact encompasses the entire scope so sliding is better captured. In this case, you may need to add additional contact faces. • Auto-detection creates more contact pairs than are necessary. In this case, you can delete the unnecessary contact regions. • Auto-detection may not create contact regions necessary for your analysis. In this case, you must add additional contact regions. You can set contact conditions manually, rather than (or in addition to) letting the application automatically detect contact regions. Within a source or target region, the underlying geometry must be of the same geometry type (for example, all surface body faces, all solid body faces). The source and target can be of different geometry types, but within itself, a source must be of the same geometry type, and a target must be of the same geometry type. To set contact regions manually: 1.

Click the Connections object in the Tree Outline (p. 3).

2.

Click the right mouse button and choose Insert> Manual Contact Region. You can also select the Contact button on the toolbar.

3.

A Contact Region item appears in the Outline. Click that item, and under the Details View (p. 11), specify the Contact and Target regions (faces or edges) and the contact type. See the Contact and Target topics in the Scope Settings section for additional Contact Region scoping restrictions.

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Setting Connections

Contact Ease of Use Features The following features are intended to assist you in performing simulations involving contact: Controlling Transparency for Contact Regions Displaying Contact Bodies with Different Colors Displaying Contact Bodies in Separate Windows Hiding Bodies Not Scoped to a Contact Region Renaming Contact Regions Based on Geometry Names Identifying Contact Regions for a Body Create Contact Debonding Flipping Contact and Target Scope Settings Merging Contact Regions That Share Geometry Saving or Loading Contact Region Settings Resetting Contact Regions to Default Settings Locating Bodies Without Contact Locating Parts Without Contact

Controlling Transparency for Contact Regions As shown below, you can graphically highlight an individual contact region. The following demo is presented as an animated GIF. Please view online if you are reading the PDF version of the help. Interface names and other components shown in the demo may differ from those in the released product. • Click on a contact region to highlight the bodies in that region. • Highlighting is due to internal transparency settings: – Transparency is set to 0.8 for bodies in selected contact region. – Transparency is set to 0.1 for bodies not in selected contact region(s). – You can change the default transparency values in the Mechanical application Connections settings of the Options dialog box. • You can disable the contact region highlighting feature in either the Details view of a contact group branch, or by accessing the context menu (right mouse click) on a contact region or contact group branch of the tree, and choosing Disable Transparency.

Displaying Contact Bodies with Different Colors By default, contact bodies are all displayed using the same color. Use the Random Colors button in the Graphics Options toolbar to display each contact using a color chosen at random each redraw.

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Contact

Displaying Contact Bodies in Separate Windows Use the Body Views button on the Connections Context Toolbar to display parts in separate auxiliary windows. As illustrated and highlighted below, the different contact bodies (Contact and Target) have colors codes associated with them. In the Details as well as the graphic windows. Contact Bodies View

Target Bodies View

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Hiding Bodies Not Scoped to a Contact Region You can hide all bodies except those that are scoped to a specific contact region. To Hide All Bodies Not Scoped to a Contact Region: 1.

Select the Contact Region object whose bodies you do not want to hide.

2.

Right-click to display the context menu.

3.

Select Hide All Other Bodies in the menu. All bodies are hidden except those that are part of the selected contact region.

Renaming Contact Regions Based on Geometry Names You can change the name of any contact region using the following choices available in the context menu that appears when you click the right mouse button on a particular contact region: • Rename: Allows you to change the contact region name to a name that you type (similar to renaming a file in Windows Explorer). • Rename Based on Definition: Allows you to change the contact region name to include the corresponding names of the items in the Geometry branch of the tree that make up the contact region. The items are separated by the word “To” in the new contact region name. You can change all the contact region names at once by clicking the right mouse button on the Connections branch, then choosing Rename Based on Definition from that context menu. A demonstration of this feature follows. The following demo is presented as an animated GIF. Please view online if you are reading the PDF version of the help. Interface names and other components shown in the demo may differ from those in the released product.

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Contact

When you change the names of contact regions that involve multiple bodies, the region names change to include the word Multiple instead of the long list of names associated with multiple bodies. An example is Bonded – Multiple To Multiple.

Identifying Contact Regions for a Body See the description for Contacts for Selected Bodies in the Correlating Tree Outline Objects with Model Characteristics (p. 6) section.

Create Contact Debonding To automatically generate a Contact Debonding object, select a Contact Region and drag and drop it onto the Fracture folder.

Flipping Contact and Target Scope Settings A valuable feature available when using asymmetric contact is the ability to swap contact and target face or edge Scope settings in the Details view. You accomplish this by clicking the right mouse button on the specific contact regions (Ctrl key or Shift key for multiple selections) and choosing Flip Contact/Target. This is illustrated below for a single region. The following demo is presented as an animated GIF. Please view online if you are reading the PDF version of the help. Interface names and other components shown in the demo may differ from those in the released product.

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Note This feature is not applicable to Face/Edge contact where faces are always designated as targets and edges are always designated as contacts.

Merging Contact Regions That Share Geometry You can merge two or more contact regions into one contact region, provided they share the same type of geometry (edges or faces). To Merge Contact Regions That Share Geometry: 1.

Select two or more contact regions in the tree that share the same type of geometry (edges or faces). Use the Shift or Ctrl key for multiple selections.

2.

Right-click to display the context menu.

3.

Select Merge Selected Contact Regions in the menu. This option only appears if the regions share the same geometry types. After selecting the option, a new contact region is appended to the list in the tree. The new region represents the merged regions. The individual contact regions that you selected to form the merged region are no longer represented in the list.

Saving or Loading Contact Region Settings You can save the configuration settings of a contact region to an XML file. You can also load settings from an XML file to configure other contact regions. To Save Configuration Settings of a Contact Region: 1.

Select the contact region whose settings you want to save.

2.

Right-click to display the context menu.

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Contact 3.

Select Save Contact Region Settings in the menu. This option does not appear if you selected more than one contact region.

4.

Specify the name and destination of the file. An XML file is created that contains the configuration settings of the contact region.

Note The XML file contains properties that are universally applied to contact regions. For this reason, source and target geometries are not included in the file. To Load Configuration Settings to Contact Regions: 1.

Select the contact regions whose settings you want to assign. Use the Shift or Ctrl key for multiple selections.

2.

Right-click to display the context menu.

3.

Select Load Contact Region Settings in the menu.

4.

Specify the name and location of the XML file that contains the configuration settings of a contact region. Those settings are applied to the selected contact regions and will appear in the Details view of these regions.

Resetting Contact Regions to Default Settings You can reset the default configuration settings of selected contact regions. To Reset Default Configuration Settings of Contact Regions: 1.

Select the contact regions whose settings you want to reset to default values. Use the Shift or Ctrl key for multiple selections.

2.

Right-click to display the context menu.

3.

Select Reset to Default in the menu. Default settings are applied to the selected contact regions and will appear in the Details view of these regions.

Locating Bodies Without Contact See the description for Bodies Without Contacts in Tree in the Correlating Tree Outline Objects with Model Characteristics (p. 6) section.

Locating Parts Without Contact See the description for Parts Without Contacts in Tree in the Correlating Tree Outline Objects with Model Characteristics (p. 6) section.

Contact in Rigid Dynamics Contact conditions are formed where rigid bodies meet. While the default contact settings and automatic detection capabilities are often sufficient for structural analyses, the default contact definition

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Setting Connections must be extended to adjacent surfaces in some cases. This is because the nature of rigid dynamics usually implies very large displacements and rotations. In rigid dynamics, only frictionless and forced friction contact is supported. The contact is always based on Pure Lagrange formulation. Contact constraint equations are updated at each time step, and added to the system matrix through additional forces of degrees of freedom called Lagrange Multipliers. In this formulation, there is no contact stiffness. Contact constraints are satisfied when the bodies are touching, and they are nonexistent when bodies are separated. Contact and Rigid Bodies Contact is formulated between rigid bodies. Hence, there is no possibility of deforming the bodies to satisfy the contact constraint equations. If the contact equations cannot eventually be satisfied, the solution will not proceed. To illustrate this, two examples are considered: Example 3: Cylindrical Shaft in a Block

• If the diameter of the cylindrical shaft is smaller than that of the hole, motion is possible. • If the diameter of the cylindrical shaft is larger than that of the hole, the simulation is not possible. • If the two diameters are exactly equal, then the analysis might fail.

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Contact Example 4: Block Sliding on Two Blocks

• If the green block slides horizontally from left to right and the height of the right block is less than that of the left block, motion is possible. • If the height of the two bottom blocks is identical and a vertical contact surface is defined between the two bottom blocks, the block might hit the vertical surface, and the solution will not proceed. • If the height of the right block is greater than the height of the left block, the green block will move back to the left.

Note Avoid ambiguous configurations whenever possible. Consider creating fillets on sharp edges as a workaround. Contact Mesh You can scope the contact objects to rigid bodies using 3-D faces in solid bodies. When you create this type of contact, the surface and edges in the contact region are meshed. The mesh helps to speed up the solution by providing an initial position to the contact points that are calculated, and it helps to drive the number of contact points used between the bodies when in contact. As each body has up to 6 degrees of freedom, a contact between two rigid bodies will restrain up to 6 relative degrees of freedom. This means that a reasonably coarse mesh is generally sufficient to define the contact surface. The contact solver will use this mesh to initiate the contact geometry calculation, but will then project back the contact points to CAD geometry. Refining the mesh can increase the solution time without always increasing the quality of the solution. Conversely, refining the mesh can be useful if the geometry is concave and the solver reports a high amount of shocks for the pair involving the concave surfaces. Contact and Time Step The rigid solver uses event-based time integration. Over each time step, the solver evaluates the trajectory of the bodies, and checks when these trajectories interfere. When interference is found (as with stops on joints), a shock will be analyzed, leading to a new velocity distribution. The physics of the velocity redistribution during the shock is based on the conservation of momentum and energy. The amount of energy lost during the shock is quantified by the coefficient of restitution. For details see, Joint Stops and Locks. The trajectory detection of interferences allows the use of rather large time steps without missing the contacts; however, transitions between adjacent contact surfaces in certain situations (such as sliding situations) often require smaller time steps.

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Setting Connections In contrast to Penalty based simulation that introduces an artificial deformation of the bodies and thus high frequencies in the simulation, the pure Lagrange formulation used in the rigid dynamics formulation does not change the frequency content of the simulation. A solution that includes contact requires an increased amount of geometrical calculation, resulting in a significantly higher overall simulation time than a solution without contact. As such, it is recommended that joints stops are used in place of contacts whenever possible. Limitations For models with sliding contacts, e.g., cams, guiding grooves, etc., small bounces due to nonzero restitution factors can cause an increase in simulation time and instabilities. Using a restitution factor of zero will significantly speed up the simulation. The Rigid Dynamics solver unifies contact regions defined between the same pairs of parts/bodies. Consequently, defining more than one contact region between the same pairs of bodies may lead to unpredictable results. The following guidelines are strongly recommended: • All contact regions defined between the same pairs of parts/bodies must have the same type. Mixing different types (e.g., frictionless and rough) may lead to incorrect results. • All contact regions defined between the same pairs of parts/bodies must follow the same order. A body defined as a target body in one contact region must not be defined as contact body in another contact region between the same pairs of parts/bodies.

Best Practices for Specifying Contact Conditions This section describes some of the practices you should try to keep in mind while defining the properties of the contact conditions for your model. • Mesh Requisites • Selecting Contact Formulation • Overlapping Contact Conditions and Boundary Conditions • Contact Behavior • Initial Contact Tool • Diagnostic Tools, NR Residuals, and Contact Result Trackers • Contact Tool Results

Mesh Requirements Defining a proper mesh is critical to contact conditions. A well-defined mesh ensures accurate stress measurements at a contact region. Furthermore, a quality mesh is essential for nonlinear contact conditions in order to obtain an accurate solution. This is especially true for curved surfaces. Use local Mesh Controls, such as Proximity Controls and Contact Sizing controls to better ensure mesh quality. Review the Apply Mesh Controls and Preview Mesh section of the Help for more information on this topic.

Selecting Contact Formulation Mechanical provides the following options for the Formulation property:

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Contact • Augmented Lagrange • Pure Penalty • MPC (Multi-Point Constraint) • Normal Lagrange Formulation methods work in combination with the specified contact Types (Bonded, No Separation, Frictionless, Rough, Frictional, and Forced Frictional Sliding). The Augmented Lagrange method is the default Formulation property for all contact types. However, you can use the Bonded and No Separation contact types with the Multi-Point Constraint (MPC) Formulation method. The examples listed below outline cases when this option is useful. Please see the Selecting a Contact Algorithm (KEYOPT(2)) section of the Mechanical APDL Contact Technology Guide for additional technical information about choosing contact formulations. • Workbench Mechanical considers the Bonded and No Separation contact types to be “linear contact.” Generally, this means that if no other nonlinearities exist (plasticity, large deformation, or frictionless contact) a nonlinear solution is not required in order to obtain an accurate solution. If a Formulation is not MPC-based, Mechanical constructs the input file to enforce a single iteration solution by issuing the NEQIT,1,FORCE command (in rare conditions this can result in an inaccurate solution, such as when a contact region is touching a constraint or a rigid body that has both a contact region and a remote displacement). In order to avoid this, you can use the MPC Formulation on the contact pairs to enable a truly linear solution or you can modify the boundary conditions to avoid contact overlap. • In a nonlinear analysis when convergence difficulties occur from Bonded/No-Separation contact situations, switching to MPC can be an attractive alternative compared to modifying the contact stiffness. A common example is where there is significant initial penetration. This is fine for a linear solution run but the presence of non-linear features can cause convergence issues. You can view NR residuals to help determine the proximity of convergence troubles. • During a Modal analysis, MPC can be employed to avoid spurious non-zero modes when gaps exist between curved surfaces. It is an inherent limitation of penalty based contact that is avoided by using an MPC based formulation. • Shell/Solid contact: When bonding shell edges to a solid, you need to make sure that the connection will properly constrain the two sides. The default (penalty-based) Formulation is not able to constrain rotational degrees of freedom that would create the possibility of a rigid body mode in cases such as a straight shell edge connected to a solid face. You can overcome this by using an MPC formulation that does provide options to constrain/couple the translation and rotation degrees of freedom.

Overlapping Contact Conditions and Boundary Conditions To avoid contact conditions that overlap constraints, use the Bonded or No Separation contact types because you will see an overall correct solution, however, the reported reactions will be inaccurate. This same phenomenon occurs in a less obvious way when you attempt to apply a Remote Displacement to a rigid body that also has bonded contact using a penalty based formulation. The example illustrated below shows a remote constraint applied to a rigid body that is also has No Separation contact using a penalty formulation. In this example, the solution is correct, however, inacRelease 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Connections curate reactions are obtained on the Remote Displacements because it is connected to the contact region via the MPC equations created. Using a remote displacement causes the solver to reorder the CE’s such that constrained node shares a CE with the bonded contact. This results in inaccurate reactions.

Using a General Joint instead of a remote displacement avoids the issue.

Regardless of the MPC formulation selection, MPC-based contact is used for Remote Boundary conditions. It is good practice to avoid having two or more MPC-based boundary conditions overlap. The solver does however attempt to negotiate and resolve the overconstraint conditions. The application issues a warning in this situation. Intelligent use of Contact Trimming as well as the Pinball setting on remote boundary conditions can also be effective tools to mitigate this behavior. In addition, MPC as well as other FE connections can be viewed via the Solution Information feature to help you graphically view the distribution of MPC equations in a model. These equations are generated from the MAPDL contact elements. See the Using Finite Element Access to Resolve Overconstraint tutorial for an example of an overconstraint situation along with steps to identify and correct it.

Contact Behavior Properly choosing your source and target topology is also important. See the specific guidelines outlined in the MAPDL contact documentation. The default behavior is auto-asymmetric wherein the MAPDL

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Contact solver determines the optimal source/target. Using a pure asymmetric behavior is suggested only for users willing to closely review each contact pair and able to determine the proper configuration.

Tip Using the Initial Contact tool can help you determine which side the MAPDL solver chooses to keep in the analysis.

Initial Contact Tool The Initial Contact Tool can be invaluable in determining that the contact is properly defined. It is also useful to determine the proper side for the source/target. Further the Initial Contact Tool can be useful to: • Make sure that the option Bonded or No Separation are selected for the Type property when contact conditions are touching and that all Rough/Frictional/Frictionless contact pairs that should be closed are, in fact, closed. • For nonlinear contact, check the amount of penetration (if any). • Even if nonlinear contact regions are in contact, make sure that more than one or two contact points are in contact, because if only one contact point is in contact, the condition may be unstable.

Diagnostic Tools, NR Residuals, and Contact Result Trackers You can use NR residuals and result trackers to help obtain a fully converged analysis. For example: • Requesting three to four Newton-Raphson residuals under the Solution Information object before starting the solution allows you to graphically view the NR residuals so as to get a qualitative measure/indication for where convergence difficulties exist in the model. • Using Contact Result Trackers provides information during the solution, such as contact penetration, the number of elements in contact, contact stiffness values, as well as many other quantities. You can use these outputs to monitor the robustness of the solution and observe the trends occurring during a nonlinear incremental solution. • If there are a few nonlinear contact regions present and you are expecting the possibility of losing contact, you can also use the Results Tracker to add the number of contacting points for those contact regions. • If no convergence is achieved, check the NR residuals. If high residuals are present at contact regions, consider using aggressive automatic contact stiffness update or reducing contact stiffness by an order of magnitude. • While solving, if bisections occur (i.e., trouble converging), check Results Tracker to see if the number of contact points is decreasing (i.e., possible loss of contact).

Contact Tool Results Following the solution process, it is strongly recommend that you insert a Contact Tool to check penetration. Penetration units are the same as that of displacement — compared with displacements in local area.

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Setting Connections For example, if local displacements are 2mm but penetration is 0.02mm, would a change in displacements by +/- 0.02mm influence overall results (including local stresses)? By comparing penetration to the results in local area (not maximum deformations of entire model), you can determine if penetration values are acceptable or not.

Caution Do not assume that penetration values are always negligible because your solution converged. You need to verify this after the solution. If you believe that penetration is excessive, modify the Penetration Tolerance (Augmented Lagrange), Normal Stiffness (Penalty or Augmented Lagrange), or use the Pure Lagrange formulation to reduce the penetration.

Joints The following topics are covered in this section: Joint Characteristics Joint Types Joint Properties Joint Stiffness Manual Joint Creation Example: Assembling Joints Example: Configuring Joints Automatic Joint Creation Joint Stops and Locks Ease of Use Features Detecting Overconstrained Conditions

Joint Characteristics A joint typically serves as a junction where bodies are joined together. Joint types are characterized by their rotational and translational degrees of freedom as being fixed or free. If you specify a Joint as a Remote Attachment it is classified as a remote boundary condition. Refer to the Remote Boundary Conditions (p. 833) section for a listing of all remote boundary conditions and their characteristics. Joints are supported in the following structural analyses: • Harmonic Response • Modal • Random Vibration • Response Spectrum • Rigid Dynamics • Static Structural

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Joints • Transient Structural

Note A Joint cannot be applied to a vertex scoped to an end release.

Nature of Joint Degrees of Freedom • For all joints that have both translational degrees of freedom and rotational degrees of freedom, the kinematics of the joint is as follows: 1. Translation: The moving coordinate system translates in the reference coordinate system. If your joint is a slot for example, the translation along X is expressed in the reference coordinate system. 2. Once the translation has been applied, the center of the rotation is the location of the moving coordinate system. • For the ANSYS Mechanical APDL solver, the relative angular positions for the spherical, general, and bushing joints are characterized by the Cardan (or Bryant) angles. This requires that the rotations about the local Y axis be restricted between –π/2 to +π/2. Thus, the local Y axis should not be used to simulate the axis of rotation if the expected rotation is large.

Joint Abstraction Joints are considered as point-to-point in the solution but the user interface shows the actual geometry. Due to this abstraction to a point-to-point joint, geometry interference and overlap between the two parts linked by the joint can be seen during an animation.

Joint Initial Conditions The nature of the degrees of freedom differs based on the selected solver. For the ANSYS Rigid Dynamics solver, the degrees of freedom are the relative motion between the parts. For the ANSYS Mechanical solver, the degrees of freedom are the location and orientation of the center of mass of the bodies. Unless specified otherwise by using joint conditions, both solvers will start with initial velocities equal to zero, but that means two different things, as explained below. • For the ANSYS Mechanical APDL solver, not specifying anything means that the bodies will be at rest. • For the ANSYS Rigid Dynamics solver, not specifying anything means that the relative velocities will be at rest. Taking the example of an in-plane double pendulum, and prescribing a constant velocity for the first grounded link will be interpreted as follows: • The second link has the same rotational velocity as the first one for the ANSYS Rigid Dynamics solver, as the relative velocity is initially equal to zero. • The second link will start at rest for the ANSYS Mechanical APDL solver.

Joint DOF Zero Value Conventions Joints can be defined using one or two coordinate systems: the Reference Coordinate System and the Mobile Coordinate System. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Connections The use of two coordinate systems provides benefits. An example is when a CAD model is not imported in an assembled configuration. In addition, it is important to define two coordinate systems so that you can employ the Configure and Set (see Manual Joint Creation (p. 564)) features as well as having the ability to update a model following a CAD update. For the ANSYS Rigid Dynamics solver, the zero value of the degrees of freedom corresponds to the matching reference coordinate system and moving coordinate system. If a joint definition includes only the location of the Mobile Coordinate System (see Modifying Joint Coordinate Systems (p. 554)), then the DOF of this joint are initially equal to zero for the geometrical configuration where the joints have been built. If the Reference Coordinate System is defined using the Override option, then the initial value of the degrees of freedom can be a nonzero value. Consider the example illustrated below. If a Translational joint is defined between the two parts using two coordinate systems, then the distance along the X axis between the two origins is the joint initial DOF value. For this example, assume it is 65 mm.

On the other hand, if the joint is defined using a single coordinate, as shown below, then the same geometrical configuration has a joint degree of freedom that is equal to zero.

For the ANSYS Mechanical APDL solver, having one or two coordinate systems has no impact. The initial configuration corresponds to the zero value of the degrees of freedom. Joint Condition Considerations When applying a Joint Condition, differences between the two solvers can arise. For example, consider the right part illustrated above moving 100 mm towards the other part over a 1 second period. (The distance along the X axis is 65 mm.) Solver ANSYS Rigid Dynamics – Two Coordinate Systems

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Displacement Joint Condition Time

Displacement

0

65

1

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Joints ANSYS Rigid Dynamics – One Coordinate System

0

0

1

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ANSYS Mechanical APDL – Two Coordinate Systems

0

0

1

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ANSYS Mechanical APDL – One Coordinate System

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You can unify the joint condition input by using a Velocity Joint Condition. Solver

Velocity Joint Condition Time

Displacement

ANSYS Rigid Dynamics – Two Coordinate Systems

0

100

1

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ANSYS Rigid Dynamics – One Coordinate System

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ANSYS Mechanical APDL – Two Coordinate Systems

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ANSYS Mechanical APDL – One Coordinate System

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Joint Types You can create the following types of joints in the Mechanical application: • Fixed Joint (p. 546) • Revolute Joint (p. 546) • Cylindrical Joint (p. 546) • Translational Joint (p. 547) • Slot Joint (p. 547) • Universal Joint (p. 548) • Spherical Joint (p. 548) • Planar Joint (p. 549) • Bushing Joint (p. 549) • General Joint (p. 551) • Point on Curve Joint (p. 552) The following sections include animated visual joint representations. Please view online if you are reading the PDF version of the help.

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Fixed Joint • Constrained degrees of freedom: All

Revolute Joint • Constrained degrees of freedom: UX, UY, UZ, ROTX, ROTY

• Example:

Cylindrical Joint • Constrained degrees of freedom: UX, UY, ROTX, ROTY

• Example:

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Joints

Translational Joint • Constrained degrees of freedom: UY, UZ, ROTX, ROTY, ROTZ

• Example:

Slot Joint • Constrained degrees of freedom: UY, UZ

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Setting Connections

Universal Joint • Constrained degrees of freedom: UX, UY, UZ, ROTY

• Example:

Spherical Joint • Constrained degrees of freedom: UX, UY, UZ

• Example:

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Joints

Planar Joint • Constrained degrees of freedom: UZ, ROTX, ROTY

• Example:

Bushing Joint • Constrained degrees of freedom: None

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Setting Connections • Example:

• A Bushing has six degrees of freedom, three translations and three rotations, all of which can potentially be characterized by their rotational and translational degrees of freedom as being free or constrained by stiffness. For a Bushing, the rotational degrees of freedom are defined as follows: – The first is a rotation around the reference coordinate system X Axis. – The second is a rotation around the Y Axis after the first rotation is applied. – The third is a rotation around the Z Axis after the first and second rotations are applied. The three translations and the three rotations form a set of six degrees of freedom. In addition, the bushing behaves, by design, as an imperfect joint, that is, some forces developed in the joint oppose the motion. The three translational degrees of freedom expressed in the reference coordinate system and the three rotations are expressed as: Ux, Uy, Uz, and Ψ, Θ, φ. The relative velocities in the reference coordinate system are expressed as: Vx, Vy, and Vz. The three components of the relative rotational velocity are expressed as: Ωx, Ωy, and Ωz. Please note that these values are not the time derivatives of [Ψ, Θ, φ]. They are a linear combination. The forces developed in the Bushing are expressed as:

Where:

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Joints [F] is force and [T] is Torque, and [K] and [C] are 6×6 matrices (defined using Stiffness Coefficients and Dampening Coefficients options). Off diagonal terms in the matrix are coupling terms between the DOFs. You can use these joints to introduce flexibility to an over-constrained mechanism. Please note that very high stiffness terms introduce high frequencies into the system and may penalize the solution time when using the ANSYS Rigid Dynamics solver. If you want to suppress motion in one direction entirely , it is more efficient to use Joint DOF Zero Value Conventions instead of a very high stiffness.

Scoping You can scope a bushing to single or multiple faces, single or multiple edges, or to a single vertex. The scoping can either be from body-to-body or body-to-ground. For body-to-body scoping, there is a reference and mobile side. For body-to-ground scoping, the reference side is assumed to be grounded (fixed), scoping is only available on the mobile side. In addition to setting the scoping (where the bushing attaches to the body), you can set the bushing location on both the mobile and reference side. The bushing reference and mobile location cannot be the same.

Applying a Bushing To add a bushing: 1.

After importing the model, highlight the Connections object in the tree.

2.

Choose either Body-Ground>Bushing or Body-Body>Bushing from the toolbar, as applicable.

3.

Highlight the new Bushing object and enter information in the Details view.

Note that matrix data for the Stiffness Coefficients and Dampening Coefficients is entered in the Worksheet. Entries are based on a Full Symmetric matrix. • A nonlinear force-deflection curve can be used to simulate multi-rate bushing with nonlinear stiffness. A linear piecewise curve is used for this purpose. To define a nonlinear stiffness-deflection curve: 1.

In the Worksheet, select the cell in which you want to define a non-linear stiffness-deflection curve.

2.

Right-click on the cell and then select Constant or Tabular.

3.

Enter a constant stiffness value or enter displacement and stiffness values (minimum of two rows of data) in the Tabular Data window. Tabular entries are plotted in the Graph window and show stiffness vs. displacement.

Note If tabular entries exist in the stiffness matrix, the MAPDL Solver does not account for constant terms and non-diagonal (coupled) terms.

General Joint • Constrained degrees of freedom: Fix All, Free X, Free Y, Free Z, and Free All.

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Setting Connections A general joint has six degrees of freedom, three translations and three rotations, all of which can potentially be characterized by their rotational and translational degrees of freedom as being free or constrained by stiffness. All the degrees of freedom are set to fixed by default. You can free the X translation, free the Y translation, free the Z translation and free all rotations. All the translational degrees of freedom can be controlled individually to be fixed or free. But there are no individual controls for rotational degrees of freedom. You can either set all rotations fixed, or just one of them (X, Y or Z) free or all free. Also, similar to a bushing, you can enter matrix data for the Stiffness Coefficients and Damping Coefficients in the Worksheet. Coupled terms (off diagonal terms in the matrix) are only allowed when all DOFs are free.

Point on Curve Joint • Constrained degrees of freedom: UY, UZ, ROTX, ROTY, ROTZ • Example:

• A point on curve joint has only one degree of freedom, which is the coordinate on the curve. UY and UZ are always equal to zero. ROTX, ROTY, and ROTZ are driven so that the mobile coordinate system of the joint always follows the reference curve. For a point on curve joint, the X axis is always tangent to the reference curve, and the Z axis is always normal to the orientation surface of the joint, pointing outward.

Scoping You can scope a point on curve joint to a single curve or multiple reference curves. You can have one or more orientation surfaces. The mobile coordinate system has to be scoped to a vertex, and the joint coordinate system has to be positioned and oriented such that: – The origin is on the curve.

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Joints – The X axis is tangent to the curve. – The Z axis is the outer normal to the surface. Note that the assembly phase may result in minor adjustments to ensure that the mobile coordinate system is properly positioned.

Joint Properties This section describes the Details view properties associated with a Joint object. Category

Property Name and Description

Definition

Connection Type Connection Type: The Connection Type property specifies the joint as either a Body-Body scoping (multiple faces) or a Body-Ground scoping (multiple faces). When defined as Body-Body, you need to define Reference category and Mobile category properties. When you specify the Connection Type as body-to-ground, the application assumes that the reference element of the joint is grounded (fixed). Type The Type property provides a drop-down list from which you can select a joints type. Refer to the Joint Types (p. 545) section of the Help for descriptions of each type. In addition to provided joint types, you can create a General joint that allows you to specify each degree of freedom as being either Fixed or Free. Torsional Stiffness The Torsional Stiffness property defines the measure of the resistance of a shaft to a twisting or torsional force. You can add torsional stiffness only for cylindrical and revolute joints. Torsional Damping The Torsional Damping property defines the measure of resistance to the angular vibration to a shaft or body along its axis of rotation. You can add torsional damping only for cylindrical and revolute joints. Suppressed Includes or excludes the joint object in the analysis.

Reference

Scoping Method This property allows you to choose to scope using a Geometry Selection (default), Named Selection, or a user-defined Remote Point.

Note If you scope a joint to a user-defined Remote Point, it is required that the remote point be located at the origin (0.0, 0.0, 0.0) of the Reference Coordinate System of the remote point. Applied By This property specifies the joint as a Remote Attachment (default) or a Direct Attachment. The Remote Attachment option uses either a user-defined or a system-generated Remote Point as a scoping mechanism. Remote Attachment Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Connections Category

Property Name and Description is the required Applied By property setting if the geometry scoping is to a single face or multiple faces, a single edge or multiple edges, or multiple vertices. The Direct Attachment option allows you to scope directly to a single vertex (Geometry) or a node (using an individually selected node or a node-based Named Selection) for flexible bodies (only) on your model. Direct Attachment is not allowed if scoped to solid bodies, as they do not have rotational degrees of freedom. Scope (or Reference Component or Remote Point) Based on the selected Scoping Method, this property displays as either «Scope», «Reference Component», or «Remote Points». When Geometry Selection is selected as the Scoping Method, this property displays with the label «Scope» and allows you to define the geometry to which the joint is applied. Once a geometry is selected, click in the Scope field and then click Apply. When Named Selection is selected as the Scoping Method, this property provides a drop-down list of available user-defined Named Selections. When Remote Point is selected as the Scoping Method, this property displays with the label «Remote Points». This property provides a drop-down list of available user-defined Remote Points. This property is not available when the Applied By property is specified as Direct Attachment. Body This read-only property displays the corresponding part/geometry name. Coordinate System The scoping of a joint must be accompanied by the definition of a joint coordinate system. This coordinate system defines the location of the joint. It is imperative that the joint coordinate system be fully associative with the geometry, otherwise, the coordinate system could move in unexpected ways when the Configure tool is used to define the initial position of the joint (see the Applying Joints section). A warning message is issued if you attempt to use the Configure tool with a joint whose coordinate system is not fully associative. Under the Reference category, the Coordinate System property provides a default Reference Coordinate System. This coordinate system accompanies a joint when the joint is added to the tree. This applies for joints whose Connection Type is either Body-Ground or Body-Body. When a joint is added, an associated coordinate system is automatically generated at a location based on the selected geometry (face, edge, or vertex). You can modify the Reference Coordinate System’s orientation axis by modifying the details of the Reference Coordinate System object contained in the joint object. Scoping a joint directly to a vertex or a node using the Direct Attachment option fixes the coordinate system to that location. Note that the Reference Coordinate System property displays automatically and is read-only. You can modify the Reference Coordinate System’s orientation axis using the Details properties in the Reference Coordinate System tree object contained under the joint object.

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Joints Category

Property Name and Description Additional information about Modifying Joint Coordinate Systems is also available, including the following topics: • Modify Coordinate System Geometry Scoping • Change Coordinate System Orientation Behavior Use the Behavior property to specify the scoped geometry as either Rigid or Deformable. Refer to the Geometry Behaviors and Support Specifications (p. 464) section for more information. Pinball Region Use the Pinball Region property to define where the joint attaches to face(s) if the default location is not desirable. By default, the entire face is tied to the joint element. This may not be desirable, warranting the input of a Pinball Region setting, for the following reasons: • If the scoping is to a topology with a large number of nodes, this can lead to an inefficient solution in terms of memory and speed. • Overlap between the joint scoped faces and other displacement type boundary conditions can lead to over constraint and thus solver failures.

Note • The Pinball Region and Behavior settings are applicable to underlying bodies that are flexible. • If a Joint’s Reference and Mobile category are scoped to separate Remote Points, the Behavior and Pinball Region properties for each category become read-only and are set to the respective remote points. Mobile

Scoping Method This property allows you to choose to scope using a Geometry Selection (default), Named Selection, or a user-defined Remote Point.

Note If you scope a joint to a user-defined Remote Point, it is required that the remote point be located at the origin (0.0, 0.0, 0.0) of the Reference Coordinate System of the remote point. Applied By This property specifies the joint as a Remote Attachment (default) or a Direct Attachment. The Remote Attachment option uses either a user-defined or a system-generated Remote Point as a scoping mechanism. Remote Attachment is the required Applied By property setting if the geometry scoping is to a single face or multiple faces, a single edge or multiple edges, or a single vertex or multiple

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Property Name and Description vertices. The Direct Attachment option allows you to scope directly to a single vertex (Geometry) or a node (using an individually selected node or a node-based Named Selection) to flexible bodies (only) on your model. Direct Attachment is not allowed if scoped to solid bodies, as they do not have rotational degrees of freedom. Scope (or Mobile Component or Remote Point) Based on the selected Scoping Method, this property displays as either «Scope», «Mobile Component», or «Remote Points». When Geometry Selection is selected as the Scoping Method, this property displays with the label «Scope» and allows you to define the geometry to which the joint is applied. Once a geometry is selected, click in the Scope field and then click Apply. When Named Selection is selected as the Scoping Method, provides a dropdown list of available user-defined Named Selections. When Remote Point is selected as the Scoping Method, this property displays with the label «Remote Points». This property provides a drop-down list of available user-defined Remote Points. This property is not available when the Applied By property is specified as Direct Attachment. Body This property is available under both the Reference and Mobile categories. This read-only property displays the corresponding part/geometry name. Coordinate System The Mobile category provides the support for the relative motion between the parts of a joint. A Mobile Coordinate System is automatically defined but is only displayed in the tree when the Initial Position property is set to Override. Scoping a joint directly to a vertex or a node using the Direct Attachment option fixes the coordinate system to that location. When scoping directly to a node or vertex using the Direct Attachment option, the default setting for the Initial Position property is Override even though the Initial Position property doesn’t display in the Details. Rather, the Coordinate System automatically displays and is read-only. You can modify the Mobile Coordinate System’s orientation axis using the Details properties in the Mobile Coordinate System tree object contained in the joint object. Additional information about Modifying Joint Coordinate Systems is also available, including the following topics: • Modify Coordinate System Geometry Scoping • Change Coordinate System Orientation Initial Position This property applies to remote attachments only (direct attachments fix the coordinate system). It provides a drop-down list with the options Unchanged and Override. The Unchanged option indicates the use of the same coordinate system for the Reference category and the Mobile category and the Override option

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Joints Category

Property Name and Description causes a Coordinate System property to display in the Mobile category with the default setting Mobile Coordinate System.

Caution If you are scoping a joint to a Remote Point, you cannot scope the Initial Position setting of a Joint’s Mobile category as Unchanged. This is also true when the Direct Attachment option is used because the Initial Position property is not available (Override is active). Behavior For remote attachments, use the Behavior property to specify the scoped geometry as either Rigid or Deformable. Refer to the Geometry Behaviors and Support Specifications (p. 464) section for more information. Pinball Region For remote attachments, use the Pinball Region property to define where the joint attaches to face(s) if the default location is not desirable. By default, the entire face is tied to the joint element. This may not be desirable, warranting the input of a Pinball Region setting, for the following reasons: • If the scoping is to a topology with a large number of nodes, this can lead to an inefficient solution in terms of memory and speed. • Overlap between the joint scoped faces and other displacement type boundary conditions can lead to over constraint and thus solver failures.

Note • The Pinball Region and Behavior properties are not visible when the Applied By method is Direct Attachment. • The Pinball Region and Behavior settings are applicable to underlying bodies that are flexible. • If a Joint’s Reference and Mobile category are scoped to separate Remote Points, the Behavior and Pinball Region properties for each category become read-only and are set to the respective remote points. Stops

See the Joint Stops and Locks (p. 590) section.

Modifying Joint Coordinate Systems For either Reference or Mobile joint coordinate systems, both the location and the orientation of the coordinate system can be changed as shown below.

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Setting Connections To move a joint coordinate system to a particular face: 1.

Highlight the Coordinate System field in the Details view of the Joint object. The origin of the coordinate system will include a yellow sphere indicating that the movement “mode” is active.

2.

Select the face that is to be the destination of the coordinate system. The coordinate system in movement mode relocates to the centroid of the selected face.

3.

Click the Apply button. The image of the coordinate system changes from movement mode to a permanent presence at the new location.

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Joints

To change the orientation of a joint coordinate system: 1.

Highlight the Coordinate System field in the Details view of the Joint object. The origin of the coordinate system will include a yellow sphere indicating that the movement “mode” is active.

2.

Click on any of the axis arrows you wish to change. Additional “handles” are displayed for each axis.

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Setting Connections

3.

Click on the handle or axis representing the new direction to which you want to reorient the initially selected axis.

The axis performs a flip transformation.

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Joints

4.

Click the Apply button. The image of the coordinate system changes from movement mode to a permanent presence at the new orientation.

You can change or delete the status of the flip transformation by highlighting the Reference Coordinate System object or a Mobile Coordinate System object and making the change or deletion under the Transformations category in the Details view of the child joint coordinate system.

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Setting Connections

When selecting either a Reference Coordinate System object or a Mobile Coordinate System object, various settings are displayed in the Details view. These are the same settings that apply to all coordinate systems, not just those associated with joints. See the following section on coordinate systems: Initial Creation and Definition (p. 483) for an explanation of these settings.

Joint Stiffness For Bushing and General Joints, Mechanical allows you to solve analyses with linear and nonlinear joint stiffness using the features of the Worksheet. For these joint types, the Worksheet provides the entry options for Constant and Tabular data. Linear or nonlinear stiffness and damping behavior is associated with the free or unrestrained components of relative motion of the joint elements. That is, the DOFs are free. For a General Joint, you must specify the DOFs as Free in order to make entries in the Worksheet matrix. Joint Stiffness calculations use the joint element MPC184. Please see its help section in the Mechanical APDL Element Reference for additional technical information as well as the MPC184 Joint Help section in the Mechanical APDL Material Reference.

Linear Joint Stiffness In the case of linear stiffness or linear damping, the values are specified as coefficients of a 6 x 6 elasticity table matrix. Joint Stiffness calculations use the joint element MPC184 and therefore only the appropriate coefficients of the stiffness or damping matrix are used in the joint element calculations.

Nonlinear Joint Stiffness For nonlinear joint stiffness, relative displacement (rotation) versus force (moment) values are calculated. For nonlinear damping behavior, velocity versus force behavior is specified. You specify nonlinear damping behavior by supplying velocity versus damping force (or moment). The following illustration represents a nonlinear stiffness or damping curve. Note that the MAPDL Solver and the Rigid Dynamics Solver assume that there is no added stiffness past the extents.

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Joints

Please see the Material Behavior of Joint Elements topic of the Connecting Multibody Components with Joint Elements section in the Mechanical APDL Multibody Analysis Guide for additional details about how this feature related to the Mechanical APDL Application.

Worksheet Using the Worksheet, you can define Stiffness Coefficients in Constant or Tabular format. Nonlinear Joint Stiffness is supported by Tabular data entries only and the entries must be made diagonally. In addition, Damping Coefficients entries only support constant values.

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Setting Connections

Note • The MAPDL Solver does not support a mixture of Constant and Tabular data entries in the Stiffness Coefficients matrix. That is, you cannot mix linear and nonlinear stiffness. • The ANSYS Rigid Dynamics Solver does support the combination of Constant and Tabular data entries. • The Report Preview feature does not display table entries from the nonlinear joint stiffness matrix.

Manual Joint Creation This section examines the steps to manually create joints. Refer to the Automatic Joint Creation (p. 589) section of the Help for a discussion about how to create joints automatically. To add a joint manually: 1.

Joints are a child object of the Connections object. The Connections object is typically generated automatically. As needed, highlight the Model object in the tree and choose the Connections button from the Model Context Toolbar once you have imported your model.

2.

Highlight the Connections object and open either Body-Ground menu or the Body-Body menu from the Connections Context Toolbar and then select your desired Joint Type. The new joint object becomes the active object in the tree.

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Joints 3.

Once inserted and active, there are a number of joint properties that require definition. For a detailed description of each of these properties, refer to the Joint Properties Help section.

Tip The Body Views button in the toolbar displays the Reference and Mobile bodies in separate windows with appropriate transparencies applied. You have full body manipulation capabilities in each of these windows.

Note You can pre-select a vertex or node (Body-Ground) or two vertices or nodes (BodyBody) and then insert a Joint to automatically create a directly attached joint.

4.

Once you have defined the desired joint properties, you may wish to use the Configure tool. The Configure tool is activated by selecting the Configure button on the Joint Configure Context Toolbar. This feature positions the Mobile body according to the joint definitions. You can then manipulate the joint interactively (for example, rotate the joint) directly on the model. The notes section shown below provides additional information about the benefits and use of the Configure feature (as well as the Assemble feature). In addition, refer to the Example: Configuring Joints Help section for an example of the use of the Configure tool.

Note • The Configure tool is not supported for Joints scoped as a Direct Attachment. • The Set button in the toolbar locks the changed assembly for use in the subsequent analysis. • The triad position and orientation may not display correctly until you click on the Set button. • The Revert button in the toolbar restores the assembly to its original configuration from DesignModeler or the CAD system.

5.

It is suggested that you consider the following: • Renaming the joint objects based on the type of joint and the names of the joined geometry. • Display the Joint DOF Checker and modify joint definitions if necessary. • Create a redundancy analysis to interactively check the influence of individual joint degrees of freedom on the redundant constraints.

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Configure and Assemble Tools Notes The Configure and Assemble tools are a good way to exercise the model and joints before starting to perform a transient analysis. They are also a way to detect locking configurations. The Assemble tool performs the assembly of the model, finding the closest part configuration that satisfies all the joints. The Configure tool performs the assembly of the model, with a prescribed value of the angle or translational degree of freedom that you are configuring. For the Assemble tool, all the joints degrees of freedom values are considered to be free. For the Configure joint, the selected DOF is considered as prescribed. In both cases, the solver will apply all constraint equations, solve the nonlinear set of equations, and finally verify that all of them are satisfied, including those having been considered as being redundant. The violation of these constraints is compared to the model size. The model size is not the actual size of the part – as the solver does not use the actual geometry, but rather a wireframe representation of the bodies. Each body holds some coordinate systems – center of mass, and joint coordinate systems. For very simple models, where the joints are defined at the center of mass, the size of the parts is zero. The violation of the constraint equations is then compared to very small reference size, and the convergence becomes very difficult to reach, leading the Configure tool or the Assemble tool to fail.

Example: Assembling Joints This section illustrates the details of assembling geometry using an example of a three-part a pendulum joint model. The Assemble feature allows you to bring in CAD geometry that may initially be in a state of disassembly. After importing the CAD geometry, you can actively assemble the different parts and Set them in the assembled configuration for the start of the analysis. The geometry shown for the example in Figure 20: Initial Geometry (p. 567) was imported into a Rigid Dynamics analysis System.

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Joints Figure 20: Initial Geometry

This geometry consists of three bodies. In Figure 20: Initial Geometry (p. 567) they are (from left to right) the Basis, the Arm, and the PendulumAxis. These three bodies have been imported completely disjointed/separate from each other. The first step to orient and assemble the bodies is to add a Body-Ground Fixed joint to the body named Basis. To do this: 1. Select Connections from the Outline. 2. From the context sensitive menu, choose Body-Ground > Fixed.

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Setting Connections 3. Click on a flat external face on the Basis body as seen in Figure 21: Selecting a Face for a Body-Ground Fixed Connection (p. 568). 4. In the Details view under Mobile, click in the Scope field and select Apply. Figure 21: Selecting a Face for a Body-Ground Fixed Connection

Next, you need to join the PendulumAxis to the Basis. Since they are initially disjoint, you need to set two coordinate systems, one for the Basis and the other for the PendulumAxis. Additionally, to fully define the relative position and orientations of the two bodies, you must define a fixed joint between them. To do this: 1. From the context sensitive menu, click on Body-Body > Fixed. 2. Highlight the face on the Basis as shown below.

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Joints

3. In the Details view, click on the Scope field under Reference and select Apply. 4. Select the cylindrical face on the PendulumAxis. 5. In the Details view, select the Scope field under Mobile and select Apply. Figure 22: Creating a Mobile Coordinate System

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Setting Connections 6. Also, change the Initial Position value under Mobile from Unchanged to Override. Now, the joint has two coordinate systems associated with it: A Reference and a Mobile coordinate system. Next, you must associate the Reference and the Mobile Coordinate Systems to the respective bodies with the appropriate orientations. To associate the Reference Coordinate System to the respective bodies: 1. In the Outline, highlight Reference Coordinate System. 2. In the Details view, click on the box next to Geometry under Origin. 3. Select the two internal rectangular faces on the Basis as shown in Figure 23: Creating the Reference Coordinate System (p. 570) and in the Details view, select Apply. This will center The Reference Coordinate System at the center of the hole on the Basis. Figure 23: Creating the Reference Coordinate System

To associate the Mobile Coordinate System to the respective bodies: 1. Highlight the Mobile Coordinate System (this coordinate system is associated with the Basis). 2. In the Details view, click in the Geometry field under Origin. 3. Select the cylindrical surface on the PendulumArm. 570

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Joints 4. In the Details view, click Apply. Figure 24: Creating the Mobile Coordinate System

Next, you will need to orient the PendulumAxis coordinate system so that it is oriented correctly in the assembly: 1. In the Mobile Coordinate System associated with the PendulumAxis, click in the box next to Geometry under Principal Axis (set to Z). 2. Select one of the vertical edges on the PendulumAxis such that the Z axis is parallel to it as shown in Figure 25: Orienting the Pendulum Axis (p. 572). In the Details view, click Apply.

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Setting Connections Figure 25: Orienting the Pendulum Axis

3. With Mobile Coordinate System highlighted in the Outline, select the x-offset button in the context sensitive menu. 4. In the Details view, enter an Offset X value of 2.5mm to align the faces of the PendulumAxis with the Basis.

Note The transformations available allow you to manipulate the coordinate systems by entering offsets or rotations in each of the 3 axis.

The two coordinate systems that were just defined should look similar to the figure below. Figure 26: Oriented Coordinate Systems

Next, you will need to define the coordinate systems to join the Arm to the PendulumAxis during assembly.

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Joints 1. From the context sensitive menu, select Body-Body > Fixed. 2. To define the Reference Scope, choose one of the faces of the Arm that will be connected to the PendulumAxis then select Apply. Figure 27: Selecting an Arm Face for Connection

3. Now, configure the Mobile Scope by selecting the flat end face of the PendulumAxis as shown in Figure 28: Scoping the Mobile Coordinate Systems (p. 574), then select Apply.

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Setting Connections Figure 28: Scoping the Mobile Coordinate Systems

4. Set the Initial Position under Mobile from Unchanged to Override. 5. Finally, set the Origin of the Reference Coordinate System to the center of the hole in the Arm using the same procedure described above for the Basis. Next, you will need to offset the Coordinate System associated with the Arm so that the faces on the Arm are aligned with the end face of the PendulumAxis. 1. With Reference Coordinate System highlighted, choose the x-offset button in the context sensitive menu. 2. Enter an Offset X value of -5mm.

Note The transformations available allow you to manipulate the coordinate systems by entering offsets or rotations in each of the 3 axis.

3. Next, Highlight the Mobile Coordinate System. This coordinate system is associated with the Arm. Click the box next to Geometry under Origin 4. Select the flat surface on the PendulumArm and click Apply. 574

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Joints

Now you will need to orient the PendulumAxis so that its faces are aligned with the faces on the Arm during the Assemble process. 1. Highlight the Mobile Coordinate System that is assigned to the PendulumAxis. 2. From the Details view, click the in the Geometry field under Principal Axis and select an edge of the PendulumAxis as shown in the figure. Figure 29: Choose an Edge to Orient the PendulumAxis Geometry

3. Under Principal Axis In the Details view, select Apply in the Geometry field to orient the PendulumAxis to this edge. Now that the three bodies have been oriented and aligned, they are ready to be assembled. 1. In the Outline, highlight Connections. 2. From the context sensitive menu, click Assemble.

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Setting Connections The parts should snap together in place and resemble Figure 30: Assembled Geometry (p. 576). If the geometry you’re attempting to assemble has not snapped into place as expected, you should retrace your previous steps to make sure that the coordinate systems are properly oriented. If your assembly has been successfully performed, then click Set in the context sensitive menu to place the assembly in its assembled position to start the analysis. Figure 30: Assembled Geometry

End of Example.

Example: Configuring Joints This section presents an example of some common joint configuration steps for a model of a pendulum created from two links, as illustrated below.

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Joints

To achieve the desired result, two revolute joints were created and configured: • The first joint is intended to allow rotation of the top link’s upper hole referenced to a stationary point (Body-Ground Revolute Joint). • The second joint is intended to allow rotation of the bottom link’s upper hole referenced to the top link’s lower hole (Body-Ground Revolute Joint). The following steps illustrate the steps of a common joint configuration: 1. After attaching the model to the Mechanical application, create the first revolute joint. • Select the Connections object in the tree and then open the Body-Ground drop-down menu on from the Connections Context Toolbar and select Revolute. The new joint object becomes the active object in the tree.

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Setting Connections

2. Scope the Mobile side of the first revolute joint to the top link’s upper hole. • Select the inner surface of the upper hole and then under Mobile category in the Details view, select the Scope field and click the Apply button.

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3. Create the second revolute joint. • Open the Body-Body drop-down menu from the Connections Context Toolbar and select Revolute. The new joint object becomes the active object in the tree.. 4. Scope the Reference side of the second joint to the top link’s lower hole. • Select inner surface of hole and the under Reference category in the Details view, select the Scope field and click the Apply button.

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5. Scope the mobile side of the second joint to the bottom link’s upper hole. • Select inside surface of hole, then under Mobile category in the Details view, select the Scope field and click the Apply button.

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Joints

6. As illustrated here, the two holes intended to form the second joint are not properly aligned to correctly create the revolute joint.

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To align the holes, you need to indicate that the two holes need to match. To achieve this, first create a coordinate system for the mobile side of the second joint, and then align the Mobile and Reference coordinate systems. Create the mobile coordinate system in this step. • Highlight the second joint, Revolute — Solid To Solid, in the tree and select Override from the dropdown menu of the Initial Position property. Note that a new Coordinate System property displays.

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7. Scope the new mobile coordinate system to the back edge of the bottom link’s upper hole. • Select the back edge of the bottom link’s upper hole, then under Mobile category, select the Coordinate System field, and then click the Apply button.

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8. Scope the existing Reference Coordinate System to the back edge of the top link’s lower hole. • Select the back edge of the top link’s lower hole, and then under Reference category, select the Coordinate System field and then click the Apply button.

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Joints

The above steps have correctly assigned the coordinate systems so that the holes can be aligned and the revolute joint can operate properly. To verify, highlight the Connections object in the tree and click the Assemble button in the Joint Configure Context toolbar.

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Setting Connections

9. Establish the initial position of each joint. • Highlight the body-to-body joint object in the tree and click the Configure button in the Joint Configure Context Toolbar. The joint is graphically displayed according to your configuration. In addition, a triad appears with straight lines representing translational degrees of freedom and curved lines representing rotational degrees of freedom. Among these, any colored lines represent the free degrees of freedom for the joint type. For the joint that is being configured, the translational displacement degrees of freedom always follow the Geometry units rather than the current Mechanical units.

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Joints

By dragging the mouse cursor on a colored line, the joint will move allowing you to set the initial position of the joint through the free translational or rotational degrees of freedom.

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For rotations, holding the Ctrl key while dragging the mouse cursor will advance the rotation in 10 degree increments. You can also type the value of the increment into the ∆ = field on the toolbar. Clicking the Configure button again cancels the joining and positioning of the joint. 10. Create the joints. • After configuring a joint’s initial position, click the Set button to create the joint.

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At this point, you also have the option of returning the configuration to the state it was in before joint creation and upon attaching to the Mechanical application by clicking the Revert toolbar button. End of Example.

Automatic Joint Creation This section discusses the automatic joint creation in the Mechanical application. You can also create joints manually as discussed in Manual Joint Creation (p. 564) section.

Creating Joints Automatically You can direct the Mechanical application to analyze your assembly and automatically create fixed joints and/or revolute joints. To create joints automatically: 1.

Insert a Connection Group object under the Connections folder either from the toolbar button or by choosing Insert from the context menu (right mouse click) for this folder.

2.

From the Details view of the Connection Group object, choose Joint from the Connection Type drop down menu.

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Select some bodies in the model based on the Scoping Method. The default is Geometry Selection scoped to All Bodies. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Connections 4.

Configure the types of joints (fixed and/or revolute) you want the Mechanical application to create automatically through the appropriate Yes or No settings in the Details view. These properties will be applied only to scoped geometries for this connection group. You can set defaults for these settings using the Options dialog box under Connections.

Note When both the Fixed Joints and Revolute Joints properties are set to Yes, the revolute joints have priority; the search for revolute joints will be processed first followed by the search for fixed joints.

5.

Choose Create Automatic Connections from the context menu (right mouse click) for the Connection Group. Appropriate joint types are created and appear in the tree as objects under the Joints folder. Each joint also includes a reference coordinate system that is represented as a child object to the joint object.

6.

Display the Joint DOF Checker or the redundancy analysis and modify joint definitions if necessary.

Joint Stops and Locks Stops and Locks are optional constraints that may be applied to restrict the motion of the free relative degree(s) of freedom (DOF) of most types of joints. Any analysis that includes a valid joint type can involve Stops and/or Locks. For the applicable joint types, you can define a minimum and maximum (min, max) range inside of which the degrees of freedom must remain. A Stop is a computationally efficient abstraction of a real contact, which simplifies geometry calculations. For Stops, a shock occurs when a joint reaches the limit of the relative motion. A Lock is the same as a Stop except that when the Lock reaches the specified limit for a degree of freedom the Lock becomes fixed in place.

Warning Use Joint Stops sparingly. The application treats the stop constraint internally as a «must be imposed» or «hard» constraint and no contact logic is used. As a result, during the given iteration of a substep, the stop constraints activate immediately if the application detects a violation of a stop limit. Depending upon the nature of the problem, the stop constraint implementation may cause the solution to trend towards an equilibriated state that may not be readily apparent to you. In addition, do not use stops to simulate zero-displacement boundary conditions. You should also avoid specifying stops on multiple joints. Finally, do not use joint stops as a substitute for contact modeling. Whenever possible, you need to use node-to-node or node-to-surface contact modeling to simulate limit conditions. For joints with free relative DOFs, the Details view displays a group of options labeled Stops. This grouping displays the applicable free DOFs (UX, UY, UZ, ROTX. etc.) for the joint type from which you specify the constraint as a Stop or a Lock (as shown below). By default, no Stop or Lock is specified, as indicated by the default option, None. You can select any combination of options. For stops and locks, the minimum and maximum values you enter are relative to the joint’s coordinate system.

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Radial Gap Stop For joints that have 3 rotational degrees of freedom, a special type of stop called a radial gap stop can be used. A radial gap stop limits the relative rotation of either the X or Y rotation, limiting the Z axis tilt of the joint’s mobile coordinate system with respect to the Z axis of the reference coordinate system. This stop idealizes a revolute joint with a gap between the inner and the outer cylinder that allows the shaft to translate and tilt in the outer cylinder, as shown on the following figure:

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Where: d is the inner diameter. D is the outer diameter. H is the height of the joint. Important Notes: • The Outer Diameter is considered to be on the reference side of the joint, so you might have to flip reference and mobile on the joint to properly define a radial gap. • The shaft is considered to be infinitely long. • If the joint allows relative translations, the center of the shaft will shift with these translations. The radial gap accounts for this center shift. • The principal axis of the radial gap is Z, meaning that the tilt occurs along the X and Y rotations of the gap. • Radial gap stops do not support tilt angles greater than 1 rad. Stops and Locks are applied to the following Joint Types. Joint Type Revolute

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Stop/Lock ANSYS Rigid Dynamics Stop/Lock ANSYS Mechanical Yes

Yes

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Joints Joint Type

Stop/Lock ANSYS Rigid Dynamics Stop/Lock ANSYS Mechanical

Cylindrical

Yes

Yes

Translational

Yes

Yes

Slot

Translational

Translational

Universal

Yes

Yes

Spherical

Radial Gap

No

Planar

Yes

Yes

General

Translational, Radial Gap

Translational

Bushing

Translational, Radial Gap

Translational

Note • When using the ANSYS Mechanical solver, Stops and Locks are active only when Large Deflection is set to On (under Analysis Settings (p. 1298)). This is because Stops and Locks make sense only in the context of finite deformation/rotation. If Large Deflection is Off, all calculations are carried out in the original configuration and the configuration is never updated, preventing the activation of the Stops and Locks. • It is important to apply sensible Stop and Lock values to ensure that the initial geometry configuration does not violate the applied stop/lock limits. Also, applying conflicting boundary conditions (for example, applying Acceleration on a joint that has a Stop, or applying Velocity on a joint that has a Stop) on the same DOF leads to non-physical results and therefore is not supported.

Solver Implications Stops and Locks are available for both the ANSYS Rigid Dynamics and ANSYS Mechanical solvers, but are handled differently in certain circumstances by the two independent solvers. • For the ANSYS Rigid Dynamics solver the shock is considered as an event with no duration, during which the forces and accelerations are not known or available for postprocessing, but generate a relative velocity «jump». • For the ANSYS Mechanical solver the stop and lock constraints are implemented via the Lagrange Multiplier method. The constraint forces due to stop and lock conditions are available when stop is established

Coefficient of Restitution For the ANSYS Rigid Dynamics solver, Stops require you to set a coefficient of restitution value. This value represents the energy lost during the shock and is defined as the ratio between the joint’s relative velocity prior to the shock and the velocity following the shock. This value can be between 0 and 1. For a restitution value of zero, a Stop is released when the force in the joint is a traction force, while a Lock does not release. A restitution factor equal to 1 indicates that no energy is lost during the shock, that is, the rebounding velocity equals the impact velocity (a perfectly elastic collision). The coefficient of restitution is not applicable to the stops on the joints when using the ANSYS Mechanical solver. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Ease of Use Features The following ease of use features are available when defining joints: • Renaming Joint Objects Based on Definition (p. 594) • Joint Legend (p. 594) • Disable/Enable Transparency (p. 595) • Hide All Other Bodies (p. 595) • Flip Reference/Mobile (p. 596) • Joint DOF Checker (p. 596) • Redundancy Analysis (p. 596) • Model Topology (p. 596)

Renaming Joint Objects Based on Definition When joints are created, the Mechanical application automatically names each of the joint objects with a name that includes the type of joint followed by the names of the joined parts included as child objects under the Geometry object folder. For example, if a revolute joint connects a part named ARM to a part named ARM_HOUSING, then the object name becomes Revolute — ARM To ARM_HOUSING. The automatic naming based on the joint type and geometry definition is by default. You can however change the default from the automatic naming to a generic naming of Joint, Joint 2, Joint 3, and so on by choosing Tools> Options and under Connections, setting Auto Rename Connections to No. If you then want to rename any joint object based on the definition, click the right mouse button on the object and choose Rename Based on Definition from the context menu. You can rename all joints by clicking the right mouse button on the Joints folder then choosing Rename Based on Definition. The behavior of this feature is very similar to renaming manually created contact regions. See Renaming Contact Regions Based on Geometry Names (p. 532) for further details including an animated demonstration.

Joint Legend When you highlight a joint object, the accompanying display in the Geometry window includes a legend that depicts the free degrees of freedom characteristic of the type of joint. A color scheme is used to associate the free degrees of freedom with each of the axis of the joint’s coordinate system shown in the graphic. An example legend is shown below for a slot joint.

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Joints

You can display or remove the joint legend using View> Legend from the main menu.

Disable/Enable Transparency The Enable Transparency feature allows you to graphically highlight a particular joint that is within a group of other joints, by rendering the other joints as transparent. The following example shows the same joint group presented in the Joint Legend (p. 594) section above but with transparency enabled. Note that the slot joint alone is highlighted.

To enable transparency for a joint object, click the right mouse button on the object and choose Enable Transparency from the context menu. Conversely, to disable transparency, click the right mouse button on the object and choose Disable Transparency from the context menu. The behavior of this feature is very similar to using transparency for highlighting contact regions. See Controlling Transparency for Contact Regions (p. 530) for further details including an animated demonstration.

Hide All Other Bodies You can hide all bodies except those associated with a particular joint. To use this feature, click the right mouse button on the object and choose Hide All Other Bodies from the context menu. Conversely, to show all bodies that may have been hidden, click the right mouse button on the object and choose Show All Bodies from the context menu.

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Flip Reference/Mobile For body-to-body joint scoping, you can reverse the scoping between the Reference and Mobile sides in one action. To use this feature, click the right mouse button on the object and choose Flip Reference/Mobile from the context menu. The change is reflected in the Details view of the joint object as well as in the color coding of the scoped entity on the joint graphic. The behavior of this feature is very similar to the Flip Contact/Target feature used for contact regions. See Flipping Contact and Target Scope Settings (p. 533) for further details including an animated demonstration.

Joint DOF Checker Once joints are created, fully defined, and applied to the model, a Joint DOF Checker calculates the total number of free degrees of freedom. The number of free degrees of freedom should be greater than zero in order to produce an expected result. If this number is less than 1, a warning message is displayed stating that the model may possibly be overconstrained, along with a suggestion to check the model closely and remove any redundant joint constraints. To display the Joint DOF Checker information, highlight the Connections object and click the Worksheet button. The Joint DOF Checker information is located just above the Joint Information heading in the worksheet.

Redundancy Analysis This feature allows you to analyze an assembly held together by joints. This analysis will also help you to solve over constrained assemblies. Each body in an assembly has a limited degree of freedom set. The joint constraints must be consistent to the motion of each body, otherwise the assembly can be locked, or the bodies may move in unwanted directions. The redundancy analysis checks the joints you define and indicates the joints that over constrain the assembly. To analyze an assembly for joint redundancies: 1.

Right-click the Connections object, and then select Redundancy Analysis to open a worksheet with a list of joints.

2.

Click Analyze to perform a redundancy analysis. All the over constrained joints are indicated as redundant.

3.

Click the Redundant label, and then select Fixed or Free to resolve the conflict manually. or Click Convert Redundancies to Free to remove all over constrained degrees of freedom.

4.

Click Set to update the joint definitions.

Note Click Export to save the worksheet to an Excel/text file.

Model Topology The Model Topology worksheet provides a summary of the joint connections between bodies in the model. This feature is a convenient way of verifying and troubleshooting a complex model that has many parts and joints. The Model Topology worksheet displays the connections each body has to other

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Joints bodies, and the joint through which these bodies are connected. Additional information for the joints is provided, including the joint type and the joint representation for the rigid body solver (i.e. whether the joint is based on degrees of freedom or constraint equations). To display the model topology, right-click on the Connections object, and then select Model Topology. The Model Topology worksheet displays in the Data View. The content of the worksheet can be exported as a text file using the Export button. Joints based on degrees of freedom are labeled either Direct or Revert in the Joint Direction column of the Model Topology table. Direct joints have their reference coordinate system on the ground side of the topology tree. Revert joints have their mobile coordinate system on the ground side. This information is useful for all post-processing based on python scripting, where internal data can be retrieved. For reverted joints, some of the joint internal results need to be multiplied by -1. Please refer to the ANSYS Rigid Dynamics Theory Manual for more information on model topology and selecting degrees of freedom.

Detecting Overconstrained Conditions Overconstrained conditions can occur when more constraints than are necessary are applied to a joint’s degrees of freedom. These conditions may arise when rigid bodies are joined together using multiple joints. The overconstraints could be due to redundant joints performing the same function, or contradictory motion resulting from improper use of joints connecting different bodies. • For the Transient Structural analysis type, when a model is overconstrained, nonconvergence of the solution most often occurs, and in some cases, overconstrained models can yield incorrect results. • For the Rigid Dynamics analysis type, when a model is overconstrained, force calculation cannot be done properly. The following features exist within the Mechanical application that can assist you in detecting possible overconstrained conditions: • Use the Joint DOF Checker (p. 596) for detecting overconstrained conditions before solving (highlight Connections object and view the Worksheet). In the following example, the original display of the Joint DOF Checker warns that the model may be overconstrained.

After modifying the joint definitions, the user displays the Joint DOF Checker again, which shows that the overconstrained condition has been resolved.

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• After solution, you can highlight the Solution Information object, then scroll to the end of its content to view any information that may have been detected on model redundancies that caused overconstrained conditions. An example is presented below.

Mesh Connection The mesh connection feature allows you to join the meshes of topologically disconnected surface bodies that may reside in different parts. In the past, this process was done at the geometry level (for example, by using the DesignModeler application to repair small gaps). However, geometry tolerances are tighter than the tolerances used by mesh connections and often lead to problems in obtaining conformal mesh. With mesh connections, the connections are made at the mesh level and tolerance is based locally on mesh size. A connection can be edge-to-edge or edge-to-face. The mesh connection feature automatically generates post pinch controls internally at meshing time, allowing the connections to work across parts so that a multibody part is not required: • Edge-to-edge – Connect an edge on one face to edge(s) on another face to pinch out mesh/gap in between. • Edge-to-face – Connect edge(s) on face(s) to another face to pinch out the gap and create conformal mesh between the edge(s) and face(s). Although pinch controls can be pre or post, all mesh connections are post. “Post” indicates that the mesh is pinched in a separate step after meshing is complete, whereas in a “pre” pinch control, the boundary mesh is pinched prior to face mesh generation. Since mesh connections are a post mesh process, the base mesh is stored to allow for quicker updates. That is, if you change a mesh connection or meshing control, only local re-meshing is required to clean up the neighboring mesh. Surface Bodies With No Shared Topology:

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Mesh Connection

Same Surface Bodies With Edge-To-Edge Mesh Connection Established:

Enabling Mesh Connections To enable the mesh connection feature: 1. Insert Mesh Connection objects manually or automatically. • For more control, or to control the engineering design, you may want to insert mesh connections manually. • Alternatively, you can use automatic mesh connections, and then review and adjust each connection as appropriate. The automatic mesh connections feature is very helpful, but it can also find and create connections that you may not want. It is best practice to review the connections, or at least be aware that if problems arise, they may be due to automatic mesh connections. See Automatic Mesh Connection and Common Connections Folder Operations for Auto Generated Connections (p. 501) for details. 2. In the Details view specify Master Geometry and Slave Geometry. • “Master” indicates the topology that will be captured after the operation is complete. In other words, it is the topology to which other topologies in the connection are projected. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Connections • “Slave” indicates the topology that will be pinched out during the operation. In other words, it is the topology that is projected to other topologies involved in the connection. The master geometry can be one or more faces or edges while the slave geometry can only be one or more edges. When specifying faces, the annotation is displayed on both sides of the faces.

Note Mesh connections support common imprints, which involve multiple slaves connected at the same location to a common master. See Common Imprints and Mesh Connections (p. 602).

3. In the Details view specify Tolerance. The Tolerance here has a similar meaning to the Tolerance Value global connection setting, and is represented as a transparent sphere. See Tolerances Used in Mesh Connections (p. 600) for details about Tolerance and how it relates to the Snap Tolerance described below. 4. For edge-to-face mesh connections only, in the Details view specify Snap to Boundary and Snap Type. When Snap to Boundary is Yes (the default) and the distance from a slave edge to the closest mesh boundary of the master face is within the specified snap to boundary tolerance, nodes from the slave edge are projected onto the boundary of the master face. The joined edge will be on the master face along with other edges on the master face that fall within the defined pinch control tolerance. See Pinch Control for details. Snap Type appears only when the value of Snap to Boundary is Yes. • If Snap Type is set to Manual Tolerance (the default), a Snap Tolerance field appears where you may enter a numerical value greater than 0. By default, the Snap Tolerance is set equal to the pinch tolerance but it can be overridden here. See Tolerances Used in Mesh Connections (p. 600) for details about Snap Tolerance and how it relates to the Tolerance described above. • If Snap Type is set to Element Size Factor, a Master Element Size Factor field appears where you may enter a numerical value greater than 0. The value entered should be a factor of the local element size of the master topology.

Note For edge-to-edge mesh connections (or edge-to-edge pinch controls), the snap tolerance is set equal to the pinch tolerance internally and cannot be modified.

5. Highlight the Mesh folder and choose Generate Mesh (right-click and choose from context menu). The surface bodies are displayed and show the mesh connections.

Tolerances Used in Mesh Connections You can set two separate tolerances to define mesh connections. Setting appropriate tolerances is often critical to obtaining high quality mesh that adequately represents the geometry you want to capture. • Tolerance – Projection tolerance to close gaps between bodies.

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Mesh Connection • Snap Tolerance – Snap to boundary tolerance to sew up mesh at the connection (applicable to edge-toface mesh connections only).

The Tolerance value is used to find which bodies should be connected to which other bodies. Setting a larger Tolerance connects more bodies together, while setting it smaller may cause some connections to be missed. For this reason, you may be motivated to set this to a larger value than needed. Setting a smaller value can avoid problems in automatic mesh connection creation, but also can result in other problems because the tolerance used in meshing is inherited from automatic mesh connection detection settings. Using a Large Tolerance Value For a large assembly for which you do not want to define mesh connections manually, automatic mesh connection detection provides many benefits. Setting a large Tolerance value to find connections yields more connections, which provides a higher level of comfort that the model is fully constrained. However, larger values can be problematic for the following reasons: • When more automatic mesh connections are created, more duplicates can be created and the mesher decides ultimately which connections to create. In general, making these decisions yourself is a better approach. • The Snap Tolerance defaults to the same value as the Tolerance. If the value of Tolerance is too large for Snap Tolerance, the mesher may be too aggressive in pinching out mesh at the connection, and hence the mesh quality and feature capturing may suffer. Using a Small Tolerance Value When mesh connections are generated automatically, the Tolerance is used on the geometry edges and faces to determine which entities should be connected. However, the connections themselves are not generated until meshing occurs. Because the connections are made on nodes and elements of the mesh rather than on the geometry, the tolerances do not translate exactly. For example, in the case below, you would want to set a Tolerance that is slightly larger than the gap in the geometry. If the gap is defined as x and the tolerance is set to x, automatic mesh connection detection could find the connection, but the meshing process may result in mesh that is only partially connected.

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Tips for Setting Tolerances As detailed above, setting the correct tolerance can be very important, and in some cases may require some speculation and/or experimentation. The following tips may help: • You can adjust the Tolerance used to generate automatic mesh connections after the connections are found. Sometimes it is a good idea to use one Tolerance value to find the mesh connections, select all the mesh connections, and then reduce or increase the Tolerance later. • Having Snap to Boundary turned on and using a Snap Tolerance are not always advisable. It depends on the model and the features you want to capture.

Mesh Sizing and Mesh Connections Mesh size has an effect on the quality and feature capture of a mesh connection as follows: • Mesh size always affects the base mesh, as features are only captured relative to mesh size. • During mesh connection processing, the base mesh is adjusted according to the common imprint/location. In cases where there is a large projection or a large difference in mesh sizes between the master entity and the slave entity, the common edge between bodies can become jagged. Also, as local smoothing takes place, there can be some problems in transition of element sizes. You can often use one of the following strategies to fix the problem: – Use more similar sizes between source and target. – Improve the tolerance used by mesh connections (either for projection, or for snapping to boundary). – Adjust the geometry’s topology so that the base mesh is more accommodating to the mesh connection. See Common Imprints and Mesh Connections (p. 602).

Common Imprints and Mesh Connections The tolerance for common imprints comes from the minimum element size in the footprint mesh, which is the horizontal plate in the example below. Common imprints are made if the gap between imprints is smaller than or equal to the minimum element size in the connection region. For this reason, setting the mesh size appropriately is important to control whether the imprints will be common or not. For example, in the case shown below, if you want a common imprint, the minimum element size (or element size if Use Advanced Size Function is Off) should be > x.

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Mesh Connection In this case, you could scope local face mesh sizing on the horizontal plate to control the sizing.

Automatic Mesh Connection Mesh connections can be automatically generated using the Create Automatic Connections option available from the right-click context menu of the Connections or Connection Group folder. See Automatically Generated Connections for details. The Tolerance Value, pairing type and other properties used for auto detection can be set in the Details view of the Connection Group folder under the Auto Detection group. Sheet thickness can also be used as a tolerance value (see Common Connections Folder Operations for Auto Generated Connections (p. 501) for details).

Mesh Connections for Selected Bodies You can select a geometric entity and lookup the Mesh Connection object in the tree outline. To find the relevant mesh connection object: • Right-click a geometric entity, and then click Go To > Mesh Connections for Selected Bodies.

Mesh Connections Common to Selected Bodies You can select a pair of geometric entities and lookup the shared Mesh Connection object in the tree outline. To find a relevant mesh connection object: • Select the appropriate pair, and then click Go To > Mesh Connections Common to Selected Bodies. This option can be helpful for finding spurious mesh connections, in which case duplicates can be removed.

Displaying Multiple Views of Mesh Connections Use the Body Views button on the Connections Context Toolbar to display parts in separate auxiliary windows. For closer inspection of mesh connections, you can use the Show Mesh option on the Graphics Options Toolbar along with Body Views.

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Diagnosing Failed Mesh Connections General Failures In the event of a general mesh connection failure, the following approach is recommended: 1. If a message provides “Problematic Geometry” information, select the message, right-click, and select Show Problematic Geometry from the context menu. This action highlights the geometry in the Geometry window that is responsible for the message.

Note Any error message that is related to a specific mesh connection will be associated with the slave geometry in the connection.

2. Select the problematic bodies, right-click, and select Go To > Mesh Connections for Selected Bodies. This action highlights all mesh connections attached to the problematic geometry. 3. Review the tolerances and mesh sizes associated with the highlighted connections. Failures Due to Defeaturing from MultiZone Quad/Tri Meshing and/or Pinch Controls Due to the patch independent nature of the MultiZone Quad/Tri mesh method, a connection may fail because the mesh is associated with some face of the body but not with the face that is involved in the connection. This type of mesh connection failure, which may also occur when pinch controls are defined, is the result of the part mesh being significantly defeatured prior to mesh connection generation. To avoid mesh connection failures when using MultiZone Quad/Tri and/or pinch controls, use one of the following approaches: • Use virtual topology to merge the faces of interest with the adjacent faces to create large patches, and then apply mesh connections to the patches. • Protect small faces in mesh connections by defining Named Selections. 604

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Mesh Connection The software does not automatically extend the connection region because doing so may lose the engineering intent of the model. For example, consider the two parts shown below.

If you are using the MultiZone Quad/Tri mesh method or pinch controls, the part mesh may look like the one shown below. Notice that one face has been defeatured out.

In this case: • If the defeatured face is the one defined in the mesh connection, the connection will fail. • If the other face is the one defined in the mesh connection, the connection will succeed. • If you include both faces in the mesh connection, the connection will succeed. Since you cannot always control which face is defeatured, the most robust and recommended approach is to include both faces in the mesh connection.

Points to Remember • Toggling suppression of mesh connections or changing their properties causes bodies affected by those mesh connections to have an unmeshed state. However, when you subsequently select Generate Mesh, only the connections will be regenerated. Since mesh connections are a post mesh process, a re-mesh is not necessary and will not occur. • Mesh connections cannot be generated incrementally. Anytime you add or change mesh connections and select Generate Mesh, processing starts with the mesh in its unsewn (pre-joined) state and then re-sews the entire assembly. This approach is necessary as mesh connections often have interdependencies which can have a ripple effect through the assembly of parts. It is often the case that a connection must be reevaluated across the assembly as a single connection may invalidate many. • With mesh connections, you can mix and match mesh methods and/or use selective meshing. • When using selective meshing and you generate mesh, only out-of-date parts are re-meshed but all mesh connections are regenerated. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Connections • Although the tolerance used for finding mesh connections and for generating mesh connections may be the same value, the tolerance itself has slightly different meanings in the two operations. When finding mesh connections, the tolerance is used to identify pairs of geometry edges or face(s)/edge(s). When generating mesh connections, the tolerance is used in pinching together the edge mesh or edge/face mesh. Since the geometry consists of NURBS, and the mesh consists of linear edges, the same tolerance may mean something slightly different in the two operations. For example, consider a geometry that consists of two cylindrical sheet parts that share an interface constructed from the same circle. Also consider that you are finding mesh connections with a tolerance of 0.0. In this case, the mesh connection is easily found because the two edges are exactly the same. However, when the mesh connection is being formed, some segments of the edge may fail to be pinched together if the mesh spacing of the two parts is different and thus the tolerance of the edge mesh is different. Also see Tolerances Used in Mesh Connections (p. 600). • For a higher order element, a midside node along the connection between a slave and a master is located at the midpoint between its end nodes, instead of being projected onto the geometry. • Although mesh connections do not alter the geometry, their effects can be previewed and toggled using the Graphics Options toolbar. • For the Shape Checking control, mesh connections support the Standard Mechanical option only. • If you define a mesh connection on topology to which a match control, mapped face meshing control, or inflation control (global or local) is already applied, a warning will be issued when you generate the mesh. The warning will indicate that the mesh connection may alter the mesh, which in turn may eliminate or disable the match, mapped face meshing, or inflation control. • Mesh connections and post pinch controls cannot be mixed with refinement or post inflation controls. • A mesh connection scoped to geometries (for the master and the slave) that lie on the same face are ignored by the mesher, and, as a result, no mesh extension is generated. • Refer to Clearing Generated Data for information about using the Clear Generated Data option on parts and bodies that have been joined by mesh connections or post pinch controls. • Refer to Using the Mesh Worksheet to Create a Selective Meshing History for information about how mesh connection operations are processed by the Mesh worksheet.

Springs A spring is an elastic element that is used to store mechanical energy and which retains its original shape after a force is removed. Springs are typically defined in a stress free or “unloaded” state. This means that no longitudinal loading conditions exist unless preloading is specified (see below). In Mechanical, the Configure feature is used to modify a Joint. If you configure a joint that has an attached spring, the spring must be redrawn in the Geometry window. In effect, the spring before the Configure action is replaced by a new spring in a new unloaded state. Springs are defined as longitudinal and they connect two bodies together or connect a body to ground. Longitudinal springs generate a force that depends on linear displacement. Longitudinal springs can

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Springs be used as a damping force, which is a function of velocity or angular velocity, respectively. Springs can also be defined directly on a Revolute Joint (p. 546) or a Cylindrical Joint (p. 546).

Note A spring cannot be applied to a vertex that is scoped to an end release. Springs are not supported for Explicit Dynamics (LS-DYNA Export) systems. The following topics are discussed in this section: • Applying Springs (p. 607) • Spring Behavior (p. 608) • Nonlinear Spring Stiffness (p. 610) • Preloading (p. 610) • Scoping (p. 611) • Spring Length (p. 611) • Advanced Features (p. 611) • Output (p. 612) • Example: Longitudinal Spring with Damping (p. 612) • Spring Incompatibility (p. 614)

Applying Springs To apply a spring: 1.

After importing the model, highlight the Model object in the tree and choose the Connections button from the toolbar.

2.

Highlight the new Connections object and choose either Body-Ground>Spring or Body-Body>Spring from the toolbar, as applicable. (Body-Ground springs are not supported for explicit dynamics analyses.)

Note You can pre-select a vertex or node (Body-Ground) or two vertices or nodes (BodyBody) and then insert a Spring to automatically create a directly attached spring. See the Scoping subsection below.

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Setting Connections 3.

Highlight the new Spring object and enter information in the Details view. Note that Longitudinal Damping is applicable only to transient analyses.

Note The length of the spring connection must be greater than 0.0 with a tolerance of 1e-8 mm.

Spring Behavior The Spring Behavior property is modifiable for a Rigid Dynamics and Explicit Dynamics analyses only. For all other analysis types, this field is read-only and displays as Both. You can define a longitudinal spring to support only tension loads or only compression loads using the Spring Behavior property. You can set this property to Both, Compression Only or Tension Only. The tension only spring does not provide any restoring force against compression loads. The compression only spring does not provide resistance against tensile loads. The stiffness of a compression only or tension only spring without any preloads is shown below. Stiffness Behavior of a Tension Only Spring:

Stiffness Behavior of a Compression Only Spring:

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Springs

Force Deflection Curve for a Tension Only Spring:

Force Deflection Curve for a Compression Only Spring:

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Setting Connections

Nonlinear Spring Stiffness A nonlinear force-deflection curve can be used to simulate multi-rate springs with nonlinear spring stiffness. A linear piecewise curve is used for this purpose. Note that spring deflection is computed using the distance between the two ends of the spring, minus the initial length. The distance between the two points is never negative, but the deflection can be negative. If you determine that a spring exists with an incorrectly defined nonlinear stiffness, the forcedeflection curve may be incorrectly defined as a result of the tabular input for nonlinear stiffness for one or more spring objects. See the details in COMBIN39 element description for more information.

Note Support Requirements • Tabular Data requires at least two rows of data. • The properties Longitudinal Damping and Preload are not applicable for Springs with nonlinear stiffness.

Points to consider for Rigid Dynamics or Explicit Dynamics analyses only: • If a nonlinear stiffness curve is defined with the Tension Only option, all points with a negative displacement are ignored. • If a nonlinear stiffness curve is defined with the Compression Only option, all points with a positive displacement are ignored. To define a nonlinear force-deflection curve: 1.

In the Spring object Details view settings, click in the Longitudinal Stiffness property.

2.

Click the arrow in the Longitudinal Stiffness property then select Tabular.

3.

Enter displacement and force values in the Tabular Data window. A graph showing force vs. displacement is displayed.

Preloading (Not supported for explicit dynamics analyses.) Mechanical also provides you with the option to preload a spring and create an initial “loaded” state. The Preload property in the Details view allows you to define a preload as a length using Free Length or to specify a specific Load. The actual length is calculated using spring end points from the Reference and Mobile scoping. For rigid dynamics analyses, the spring will be under tension or compression depending upon whether you specified the free length as smaller or greater than the spring length, respectively. If preload is specified in terms of Load, a positive value creates tension and a negative value creates compression. When the spring is linear (defined by a constant stiffness) the Rigid Dynamics solver deduces the spring freelength by subtracting the value L=F/K (where F is the preload and K is the stiffness) from the actual spring length. Note that this offset is also applied to the elongation results. When the spring is non-linear (defined by a force/displacement table), this offset is not taken into account.

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Springs

Spring Length The read-only property Spring Length displays the actual length of the spring which is calculated using the end points from the Reference and Mobile scoping.

Scoping You select the Scope of springs as body-to-body or body-to-ground using the property of the Scope category and you define a spring’s end points using the properties of the Reference and Mobile categories. For body-to-ground property specification, the Reference is assumed to be grounded (fixed); scoping is only available on the Mobile side. Since this is a unidirectional spring, these two locations determine the spring’s line of action and as such the spring’s reference and mobile locations cannot be the same as this would result in a spring with zero length. In addition, the Reference and Mobile categories provide the scoping property Applied By. This property allows you to specify the connection as either a Direct Attachment or a Remote Attachment. The Remote Attachment option (default) uses a Remote Point as a scoping mechanism. The Direct Attachment option allows you to scope directly to a single vertex or a node of the model.

Note If specified as a Remote Attachment, springs are classified as remote boundary conditions. Refer to the Remote Boundary Conditions (p. 833) section for a listing of all remote boundary conditions and their characteristics. You can scope of a spring to a: • Single face or to multiple faces (applied as a Remote Attachment only). • Single edge or multiple edges (applied as a Remote Attachment only). • Single vertex (can be applied as either a Remote Attachment or as a Direct Attachment) or multiple vertices (applied as a Remote Attachment only).

Note A spring cannot be applied to a vertex that is scoped to an end release.

• Single node (applied as a Direct Attachment only). See the Spring Object Reference page of the Help for additional information about the available categories and properties.

Advanced Features If specified as a Remote Attachment, the Reference and Mobile groups for Springs each include the following advanced properties: • Behavior — This property allows you to specify the scoped geometry as either Rigid or Deformable. Refer to the Geometry Behaviors and Support Specifications (p. 464) section for more information.

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Setting Connections • Pinball Region — This property allows you to specify the contact search size.

Note The Behavior setting is applicable to underlying bodies that are flexible.

Output Several outputs are available via a spring probe.

Example: Longitudinal Spring with Damping This example shows the effect of a longitudinal spring connecting a rectangular bar to ground to represent a damper. A Transient Structural analysis was performed in the environment shown:

The following are the Details view settings of the Spring object:

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Springs

Presented below is the Total Deformation result: The following demo is presented as an animated GIF. Please view online if you are reading the PDF version of the help. Interface names and other components shown in the demo may differ from those in the released product.

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Setting Connections

Spring Incompatibility (applicable only to rigid dynamics analyses) If the preload for a longitudinal spring is a tensile load, then the spring cannot be defined as compression only. Alternatively, if the preload is a compressive load, then the spring cannot be defined as tension only. Should this case occur, the spring will be marked as underdefined and if you attempt to solve such a case, the following error message is displayed: “The preload for a spring is incompatible with its behavior being tension only spring or compression only spring.”

Beam Connections A beam is a structural element that carries load primarily in bending (flexure). Using the Beam feature, you can establish a body-to-body or a body-to-ground connections. You can use beams for all structural analyses. To add a Beam object: 1. Select the Connections folder in the object tree. As needed, add a Connections folder by selecting the Model object and clicking the Connections button on the Model Context Toolbar. 2. On the Connections Context Toolbar, click Body-Ground or Body-Body and then click Beam to add a circular beam under connections. 3. In the Details View, under Definition, click the Material fly-out menu, and then select a material for the beam. 4. Enter a beam radius in the Radius field. 5. If necessary, modify the Scope setting. The Scope property of the Scope category allows you to change the scoping from Body-Body to Body-Ground. Similar to Springs, this property defines the beam’s end points in coordination with the properties of the Reference and Mobile categories. For body-to-ground property specification, the Reference is assumed to be grounded (fixed) and as a result scoping is required on the Mobile side only. Because beam’s define a span, the reference and mobile locations determine a distance and as such the reference and mobile locations cannot be the same. In addition, the Reference and Mobile categories provide the scoping property Applied By. This property allows you to specify the connection as either a Direct Attachment or a Remote Attachment. The Remote Attachment option (default) uses a Remote Point as a scoping mechanism. The Direct Attachment option allows you to scope directly to a single vertex or a node of the model. Direct Attachment is not allowed if scoped to solid bodies, as they do not have rotational degrees of freedom. 6. Under the Reference category, for Body-Body connections only: a. Specify the Scoping Method property as either Geometry Selection, Named Selection, or Remote Point. Based on the selection made in this step, select a: • geometry (faces, edges, or vertices) and click Apply in the Scope property field. or…

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Beam Connections • single node (Direct Attachment Only) and click Apply in the Scope property. In order to select an individual node, you need to first generate a mesh on the model, and then choose the Show Mesh button on the Graphics Options Toolbar, and then specify Select Mesh as the Select Type from the Graphics Toolbar. or… • user-defined node-based named selection (Direct Attachment Only) or a user-defined geometrybased named selection (Remote Attachment Only) from the drop-down list of the Named Selection property. or… • user-defined remote point (Remote Attachment Only) from the drop-down list of the Remote Point property.

Note You can pre-select a vertex or node (Body-Ground) or two vertices or nodes (BodyBody) and then insert a Beam to automatically create a directly attached beam.

7. Specify the following properties as needed. These properties are available under the Reference Category (Body-Body or Body-Ground connections) when the Applied By property is set to Remote Attachment: • Coordinate System: select a different coordinate system if desired. • Reference X Coordinate: enter a value as needed. • Reference Y Coordinate enter a value as needed. • Behavior: specify this property as either Rigid or Deformable. Refer to the Geometry Behaviors and Support Specifications section for more information. • Pinball Radius: enter a value as needed. 8. Under Mobile Category (Body-Body or Body-Ground connections): a. Specify the Scoping Method property as either Geometry Selection, Named Selection, or Remote Point. Based on the selection made in this step, select a: • geometry (faces, edges, or vertices) and click Apply in the Scope property field. or… • single node (Direct Attachment Only) and click Apply in the Scope property. In order to select an individual node, you need to first generate a mesh on the model, and then choose the Show Mesh button on the Graphics Options Toolbar, and then specify Select Mesh as the Select Type from the Graphics Toolbar. or… • user-defined node-based named selection (Direct Attachment Only) or a user-defined geometrybased named selection (Remote Attachment Only) from the drop-down list of the Named Selection property. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Connections or… • user-defined remote point (Remote Attachment Only) from the drop-down list of the Remote Point property. b. Specify the following properties as needed. These properties are available under the Mobile Category (Body-Body or Body-Ground connections) when the Applied By property is set to Remote Attachment: • Coordinate System: select a different coordinate system if desired. • Mobile X Coordinate: enter a location value. • Mobile Y Coordinate enter a location value. • Behavior: specify this property as either Rigid or Deformable. Refer to the Geometry Behaviors and Support Specifications section for more information. • Pinball Radius: enter a dimension value. See the Beam Object Reference page of the Help for additional information about the available categories and properties.

Note • For Body-Ground beam connections, the reference side is fixed. For Body-Body beam connections, you must define the reference point for each body. • The length of the beam connection must be greater than 0.0 with a tolerance of 1e-8 mm. • Beam connections support structural analyses only. In thermal stress analyses, beam connections are assigned the environment temperature in the structural analysis. You can include a beam in a thermal analysis by creating a line body and as a result providing for temperature transference.

The Beam Probe results provide you the forces and moments in the beam from your analysis.

Spot Welds Spot welds are used to connect individual surface body parts together to form surface body model assemblies, just as a Contact Region is used for solid body part assemblies. Structural loads are transferred from one surface body part to another via the spot weld connection points, allowing for simulation of surface body model assemblies.

Spot Weld Details Spot welds are usually defined in the CAD system and automatically generated upon import, although you can define them manually in the Mechanical application after the model is imported. Spot welds then become hard points in the geometric model. Hard points are vertices in the geometry that are linked together using beam elements during the meshing process.

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Spot Welds Spot weld objects are located in a Connection Group folder. When selected in the tree, they appear in the graphical window highlighted by a black square around a white dot on the underlying vertices, with an annotation. If a surface body model contains spot weld features in the CAD system and the Auto Detect Contact On Attach is turned on in Workbench Tools>Options>Mechanical, then Spot Weld objects are generated when the model is read into the Mechanical application. Spot weld objects will also get generated during geometry refresh if the Generate Automatic Connection On Refresh is set to Yes in the Details view of the Connections folder. This is similar to the way in which the Mechanical application automatically constructs contacts when reading in assemblies models and refreshing the geometry. You can manually generate spot welds as you would insert any new object into the Outline tree. Either insert a spot weld object from the context menu and then pick two appropriate vertices in the model, or pick two appropriate vertices and then insert the spot weld object. You can define spot welds for CAD models that do not have a spot weld feature in the CAD system, as long as the model contains vertices at the desired locations. You must define spot welds manually in these cases.

Spot Weld Application Spot welds do not act to prevent penetration of the connected surface body in areas other than at the spot weld location. Penetration of the joined surface body is possible in areas where spot welds do not exist. Spot welds transfer structural loads and thermal loads as well as structural effects between solid, surface, and line body parts. Therefore they are appropriate for displacement, stress, elastic strain, thermal, and frequency solutions. DesignModeler generates spot welds. The only CAD system whose spot welds can be fully realized in ANSYS Workbench at this time is NX. The APIs of the remaining CAD systems either do not handle spot welds, or the ANSYS Workbench software does not read spot welds from these other CAD systems.

Spot Welds in Explicit Dynamics Analyses Spot welds provide a mechanism to rigidly connect two discrete points in a model and can be used to represent welds, rivets, bolts etc. The points usually belong to two different surfaces and are defined on the geometry (see DesignModeler help). During the solver initialization process, the two points defining each spot weld will be connected by a rigid beam element. Additionally, rigid beam elements will be generated on each surface to enable transfer of rotations at the spot weld location (see figure below). If the point of the spot weld lies on a shell body, both translational and rotational degrees of freedom will be linked at the connecting point. If the point of the spot weld lies on a the surface of a solid body, additional rigid beam elements will be generated to enable transfer of rotations at the spot weld location. Spot welds can be released during a simulation using the Breakable Stress or Force option. If the stress criteria is selected the user will be asked to define an effective cross sectional area. This is used to convert the defined stress limits into equivalent force limits. A spot weld will break (release) if the following criteria is exceeded

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Setting Connections Where: fn and fs are normal and shear interface forces Sn and Ssare the maximum allowed normal and shear force limits n and s are user defined exponential coefficients Not that the normal interface force fn is non-zero for tensile values only. After failure of the spot weld the rigid body connecting the points is removed from the simulation. Spot welds of zero length are permitted. However, if such spot welds are defined as breakable the above failure criteria is modified since local normal and shear directions cannot be defined. A modified criteria is used with global forces

Where,

are the force differences across the spot weld in the global coordinate system.

Note A spot weld is equivalent to a rigid body and as such multiple nodal boundary conditions cannot be applied to spot welds.

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Body Interactions in Explicit Dynamics Analyses

End Releases This feature allows you to release certain degrees of freedoms at a vertex shared by two or more edges of one or more line bodies, by using an End Release object. You can only apply one end release at the vertex and the edge must be connected to another edge at this vertex. To add an End Release: 1. Add a Connections folder if one is not already in the tree, by highlighting the Model object and choosing Connections from the Model Context Toolbar (p. 55) or by choosing Insert >Connections from the context menu (right-click). 2. Add an End Release object by highlighting the Connections folder and choosing End Release from the Connections Context Toolbar (p. 57) or by choosing Insert >End Release from the context menu (rightclick). 3. Set the following in the Details view: a. Scoping Method as Geometry Selection (default) or Named Selection. b. Edge Geometry and Vertex Geometry, respectively. The vertex should be one of the two end vertices of the edge. c. Coordinate System as the Global Coordinate System or a local coordinate system that you may have defined previously. d. Release any of the translational and/or rotational degrees of freedoms in X, Y and Z directions by changing the individual settings from Fixed to Free. e. Connection Behavior as either Coupled (default) or Joint, using a coupling or a general joint, respectively.

Notes • The end release feature is only applicable in structural analyses that use the ANSYS solver. The environment folder of other solvers will become underdefined when one or more End Release objects are present. • An end release object requires that the vertex must be on an edge and it should be shared with one or more other edges or one or more surface bodies. • A vertex cannot be scoped to more than one end release object. • The following boundary conditions are not allowed to be applied to a vertex or an edge that is already scoped to an end release The object will become underdefined with an error message: Fixed Support, Displacement, Simply Supported, Fixed Rotation, Velocity. • The following remote boundary conditions are not allowed to be applied to a vertex scoped to an end release The object will become underdefined with an error message: Remote Displacement, Remote Force, Moment, Point Mass, Thermal Point Mass, Spring, Joint.

Body Interactions in Explicit Dynamics Analyses Within an explicit dynamics analysis, the body interaction feature represents contact between bodies and includes settings that allow you to control these interactions. If the geometry you use has two or Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Connections more bodies in contact, a Body Interactions object folder appears by default under Connections in the tree. Included in a Body Interactions folder are one or more Body Interaction objects, with each object representing a contact pair. You can also manually add these two objects: • To add a Body Interactions folder, highlight the Connections folder and choose Body Interactions from the toolbar. A Body Interactions folder is added and includes one Body Interaction object. • To add a Body Interaction object to an existing Body Interactions folder, highlight the Connections folder, the Body Interactions folder, or an existing Body Interaction object, and choose Body Interaction from the toolbar.

General Notes Each Body Interaction object activates an interaction for the bodies scoped in the object. With body interactions, contact detection is completely automated in the solver. At any time point during the analysis any node of the bodies scoped in the interaction may interact with any face of the bodies scoped in the interaction. The interactions are automatically detected during the solution. The default frictionless interaction type that is scoped to all bodies activates frictionless contact between any external node and face that may come into contact in the model during the analysis. To improve the efficiency of analyses involving large number of bodies, you are advised to suppress the default frictionless interaction that is scoped to all bodies, and instead insert additional Body Interaction objects which limit interactions to specific bodies. The union of all frictional/frictionless body interactions defines the matrix of possible body interactions during the analysis. For example, in the model shown below: • Body A is traveling towards body B and we require frictional contact to occur. A frictional body interaction type scoped only to bodies A and B will achieve this. Body A will not come close to body C during the analysis so it does not need to be included in the interaction. • Body B is bonded to body C. A bonded body Interaction type, scoped to bodies B and C will achieve this. • If the bond between bodies B and C breaks during the analysis, we want frictional contact to take place between bodies B and C. A frictional body interaction type scoped only to bodies B and C will achieve this.

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Body Interactions in Explicit Dynamics Analyses

A bonded body interaction type can be applied in addition to a frictional/frictionless body interaction. A reinforcement body interaction type be can be applied in addition to a frictional/frictionless body interaction. Object property settings are included in the Details view for both the Body Interactions folder and the individual Body Interaction objects. Refer to the following sections for descriptions of these properties. Properties for Body Interactions Folder Interaction Type Properties for Body Interaction Object Identifying Body Interactions Regions for a Body

Properties for Body Interactions Folder All properties for the Body Interactions folder are included in an Advanced category and define the global properties of the contact algorithm for the analysis. These properties are applied to all Body Interaction objects and to all frictional and frictionless manual contact regions. This section includes descriptions of the following properties for the Body Interactions folder: Contact Detection Formulation Shell Thickness Factor Body Self Contact Element Self Contact Tolerance Pinball Factor Time Step Safety Factor Limiting Time Step Velocity Edge on Edge Contact

Contact Detection The available choices are described below.

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Setting Connections

Trajectory The trajectory of nodes and faces included in frictional or frictionless contact are tracked during the computation cycle. If the trajectory of a node and a face intersects during the cycle a contact event is detected. The trajectory contact algorithm is the default and recommended option in most cases for contact in Explicit Dynamics analyses. Contacting nodes/faces can be initially separated or coincident at the start of the analysis. Trajectory based contact detection does not impose any constraint on the analysis time step and therefore often provides the most efficient solution.

Note Trajectory Contact Detection is not supported for a distributed solve. If you would like to use Trajectory Contact Detection for a distributed solve, please contact ANSYS Technical Support. Note that nodes which penetrate into another element at the start of the simulation will be ignored for the purposes of contact and thus should be avoided. To generate duplicate conforming nodes across a contact interface: 1. Use the multibody part option in DesignModeler and set Shared Topology to Imprint. 2. For meshing, use Contact Sizing, the Arbitrary match control or the Match mesh Where Possible option of the Patch Independent mesh method.

Proximity Based The external faces, edges and nodes of a mesh are encapsulated by a contact detection zone. If during the analysis a node enters this detection zone, it will be repelled using a penalty based force.

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Body Interactions in Explicit Dynamics Analyses

Note • An additional constraint is applied to the analysis time step when this contact detection algorithm is selected. The time step is constrained such that a node cannot travel through a fraction of the contact detection zone size in one cycle. The fraction is defined by the Time Step Safety Factor (p. 626) described below. For analyses involving high velocities, the time step used in the analysis is often controlled by the contact algorithm. • The initial geometry/mesh must be defined such that there is a physical gap/separation of at least the contact detection zone size between nodes and faces in the model. The solver will give error messages if this criteria is not satisfied. This constraint means this option may not be practical for very complex assemblies. • Proximity Based Contact is not supported in 2D explicit dynamics analyses.

Formulation This property is available if Contact Detection is set to Trajectory. The available choices are described below.

Penalty If contact is detected, a local penalty force is calculated to push the node involved in the contact event back to the face. Equal and opposite forces are calculated on the nodes of the face in order to conserve linear and angular momentum.

Trajectory based penalty force,

Proximity based penalty force, Where: D is the depth of penetration M is the effective mass of the node (N) and face (F)

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Setting Connections ∆t is the simulation time step

Note • Kinetic energy is not necessarily conserved. You can track conservation of energy in contact using the Solution Information object, the Solution Output, or one of the energy summary result trackers. • The applied penalty force will push the nodes back towards the true contact position during the cycle. However, it will usually take several cycles to satisfy the contact condition.

Decomposition Response All contacts that take place at the same point in time are first detected. The response of the system to these contact events is then calculated to conserve momentum and energy. During this process, forces are calculated to ensure that the resulting position of nodes and faces does not result in further penetration at that time point.

Note • The decomposition response algorithm cannot be used in combination with bonded contact regions. The formulation will be automatically switch to penalty if bonded regions are present in the model. • The decomposition response algorithm is more impulsive (in a given cycle) than the penalty method. This can give rise to large hourglass energies and energy errors.

Shell Thickness Factor This property is available if the geometry includes one or more surface bodies and if Contact Detection is set to Trajectory. The Shell Thickness Factor allows you to control the effective thickness of surface bodies used in the contact. You can specify a value between 0.0 and 1.0. • A value of 0.0 means that contact will ignore the physical thickness of the surface body and the contact surface will be coincident with the mid-plane of the shell • A value of 1.0 means that the contact shell thickness will be equal to the physical shell thickness. The contact surface will be offset from the mid-plane of the shell by half the shell thickness (on both sides of the shell)

Note Only node to surface contact is currently supported. For shell to shell contact, this means that contact takes place when the shell node impacts the shell contact surface as described above.

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Body Interactions in Explicit Dynamics Analyses

Body Self Contact When set to Yes, the contact detection algorithm will check for external nodes of a body contacting with faces of the same body in addition to other bodies. This is the most robust option since all possible external contacts should be detected. When set to No, the contact detection algorithm will only check for external nodes of a body contacting with external faces of other bodies. This setting reduces the number of possible contact events and can therefore improve efficiency of the analysis. This option should not be used if a body is likely to fold onto itself during the analysis, as it would during plastic buckling for example. When set to Program Controlled, the behavior of self contact is determined by the Analysis Settings Preference Type. Presented below is an example of a model that includes self impact.

Element Self Contact When set to Yes, automatic erosion (removal of elements) is enabled when an element deforms such that one of its nodes comes within a specified distance of one of its faces. In this situation, elements are removed before they become degenerated. Element self contact is very useful for impact penetration examples where removal of elements is essential to allow generation of a hole in a structure.

When set to Program Controlled, the behavior of self contact is determined by the Analysis Settings Preference Type.

Tolerance This property is available if Contact Detection is set to Trajectory and Element Self Contact is set to Yes.

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Setting Connections Tolerance defines the size of the detection zone for element self contact when the trajectory contact option is used. (see Element Self Contact (p. 625)). The value input is a factor in the range 0.1 to 0.5. This factor is multiplied by the smallest characteristic dimension of the elements in the mesh to give a physical dimension. A setting of 0.5 effectively equates to 50% of the smallest element dimension in the model.

Note The smaller the fraction the more accurate the solution.

Pinball Factor This property is available if Contact Detection is set to Proximity Based. The pinball factor defines the size of the detection zone for proximity based contact. The value input is a factor in the range 0.1 to 0.5. This factor is multiplied by the smallest characteristic dimension of the elements in the mesh to give a physical dimension. A setting of 0.5 effectively equates to 50% of the smallest element dimension in the model.

Note The smaller the fraction the more accurate the solution. The time step in the analysis could be reduced significantly if small values are used (see Time Step Safety Factor (p. 626)).

Time Step Safety Factor This property is available if Contact Detection is set to Proximity Based. For proximity based contact, the time step used in the analysis is additionally constrained by contact such that in one cycle, a node in the model cannot travel more than the detection zone size, multiplied by a safety factor. The safety factor is defined with this property and the recommended default is 0.2. Increasing the factor may increase the time step and hence reduce runtimes, but may also lead to missed contacts. The maximum value you can specify is 0.5.

Limiting Time Step Velocity This property is available if Contact Detection is set to Proximity Based. For proximity based contact, this setting limits the maximum velocity that will be used to compute the proximity based contact time step calculation.

Edge on Edge Contact This property is available if Contact Detection is set to Proximity Based.

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Body Interactions in Explicit Dynamics Analyses By default, contact events in explicit dynamics are detected by discrete nodes impacting surface events. Use this option to extend the contact detection to include discrete edges impacting other edges in the model.

Note this option is numerically intensive and can significantly increase runtimes. It is recommended that you compare results with and without edge contact to make sure this feature is required.

Interaction Type Properties for Body Interaction Object This section includes descriptions of the interaction types for the Body Interaction object: Frictionless Type Frictional Type Bonded Type Reinforcement Type

Frictionless Type Setting Type to Frictionless activates frictionless sliding contact between any exterior node and any exterior face of the scoped bodies. Individual contact events are detected and tracked during the analysis. The contact is symmetric between bodies (that is, each node will belong to a master face impacted by adjacent slave nodes; each node will also act as a slave impacting a master face).

Supported Connections Explicit Dynamics Connection Geometry

Volume

Shell

Line

Volume

Yes

Yes

Yes

Shell

Yes

Yes

Yes

Line

Yes

Yes

*Yes

*Only for Contact Detection = Proximity Based and Edge on Edge Contact = Yes (This option switches on contact between ALL lines / bodies / edges, that is, there is no dependence on the scoping selection of body interactions.) Explicit Dynamics (LS-DYNA Export) Connection Geometry

Volume

Shell

Line

Volume

Yes

Yes

No

Shell

Yes

Yes

No

Line

No

No

No

Frictional Type Descriptions of the following properties are also addressed in this section: • Friction Coefficient

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Setting Connections • Dynamic Coefficient • Decay Constant Setting Type to Frictional activates frictional sliding contact between any exterior node and any exterior face of the scoped bodies. Individual contact events are detected and tracked during the simulation. The contact is symmetric between bodies (that is, each node will belong to a master face impacted by adjacent slave nodes, each node will also act as a slave impacting a master face). Friction Coefficient: A non-zero value will activate Coulomb type friction between bodies (F = µR). The relative velocity (ν) of sliding interfaces can influence frictional forces. A dynamic frictional formulation for the coefficient of friction can be used. µ = µd + (µs – µd) e-βν where µs = friction coefficient µd = dynamic coefficient of friction β = exponential decay coefficient ν = relative sliding velocity at point of contact Non-zero values of the Dynamic Coefficient and Decay Constant should be used to apply dynamic friction.

Supported Connections Explicit Dynamics Connection Geometry

Volume

Shell

Line

Volume

Yes

Yes

Yes

Shell

Yes

Yes

Yes

Line

Yes

Yes

*Yes

*Only for Contact Detection = Proximity Based and Edge on Edge Contact = Yes (This option switches on contact between ALL lines / bodies / edges, that is, there is no dependence on the scoping selection of body interactions.) Explicit Dynamics (LS-DYNA Export) Connection Geometry

Volume

Shell

Line

Volume

Yes

Yes

No

Shell

Yes

Yes

No

Line

No

No

No

Bonded Type Descriptions of the following properties are also addressed in this section: 628

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Body Interactions in Explicit Dynamics Analyses • Maximum Offset • Breakable – Stress Criteria → Normal Stress Limit → Normal Stress Exponent → Shear Stress Limit → Shear Stress Exponent External nodes of bodies included in bonded interactions will be tied to faces of bodies included in the interaction if the distance between the external node and the face is less than the value (tolerance) defined by the user in Maximum Offset. The solver automatically detects the bonded nodes/faces during the initialization phase of the analysis. Note that it is important to select an appropriate value for the Maximum Offset (tolerance). The automatic search will bond everything together which is found within this value (tolerance). Use the custom variable BOND_STATUS to check bonded connections in Explicit Dynamics. The variable records the number of nodes bonded to the faces on an element during the analysis. This can be used not only to verify that initial bonds are generated appropriately, but also to identify bonds that break during the simulation. Maximum Offset defines the tolerance used at initialization to determine whether a node is bonded to a face. Breakable = No implies that the bond will remain throughout the analysis. Breakable = Stress Criteria implies that the bond may break (or be released) during the analysis. The criteria for breaking a bond is defined as: (σn/σnlim it)n + (|σs|/σslim it)m > or equal to 1 where σnlim it = Normal Stress Limit n = Normal Stress Exponent σslim it = Shear Stress Limit m = Shear Stress Exponent The options in the Advanced section are all currently ignored by the Explicit solver, including the Advanced > Pinball region option. The tolerance must be defined via the Maximum Offset value and is only used at initialization.

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Setting Connections Connection Geometry

Volume

Shell

Line

Volume

Yes

Yes

Yes

Shell

Yes

Yes

Yes

Line

Yes

Yes

Yes

Note Bonded body interactions and contact are not supported for 2D Explicit Dynamics analyses. Explicit Dynamics (LS-DYNA Export)* Connection Geometry

Volume

Shell

Line

Volume

Yes

Yes

No

Shell

Yes

Yes

No

Line

Yes

Yes

No

*The above matrix is valid only for Contact Regions. Bonded body interactions are not supported at all.

Reinforcement Type This body interaction type is used to apply discrete reinforcement to solid bodies. All line bodies scoped to the object will be flagged as potential discrete reinforcing bodies in the solver. On initialization of the solver, all elements of the line bodies scoped to the object which are contained within any solid body in the model will be converted to discrete reinforcement. Elements which lie outside all volume bodies will remain as standard line body elements. The reinforcing beam nodes will be constrained to stay at the same initial parametric location within the volume element they reside during element deformation. Typical applications involve reinforced concrete or reinforced rubber structures likes tires and hoses. If the volume element to which a reinforcing node is tied is eroded, the beam node bonding constraint is removed and becomes a free beam node. On erosion of a reinforcing beam element node, if inertia is retained, the node will remain tied to the parametric location of the volume element. If inertia is not retained, the node will also be eroded

Note Volume elements that are intersected by reinforcement beams, but do not contain a beam node, will not be experiencing any reinforced beam forces. Good modeling practice is

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Body Interactions in Explicit Dynamics Analyses therefore to have the element size of the beams similar or less than that of the volume elements. Table 3: Example: Drop test onto reinforced concrete beam

Note that the target solid bodies do not need to be scoped to this object – these will be identified automatically by the solver on initialization.

Supported Connections Explicit Dynamics Connection Geometry

Volume

Shell

Line

Volume

No

No

*Yes

Shell

No

No

No

Line

*Yes

No

No

*Only the line body needs to be included in the scope. The ANSYS AUTODYN solver automatically detects which volume bodies that the line body passes through.

Note Reinforcement body interactions are not supported for 2D Explicit Dynamics analyses. Explicit Dynamics (LS-DYNA Export) Connection Geometry

Volume

Shell

Line

Volume

No

No

No

Shell

No

No

No

Line

No

No

No

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Setting Connections

Identifying Body Interactions Regions for a Body See the description for Body Interactions for Selected Bodies in the section Correlating Tree Outline Objects with Model Characteristics (p. 6).

Bearings A bearing is a two-dimensional elastic element used to confine relative motion and rotation of a rotating machinery part. Bearings are a critical support for Rotordynamics analyses and as such, a good bearing design is essential to ensure stability of machinery parts under high speed rotations. Similar to a spring, a bearing has the structural characteristics of longitudinal stiffness and damping. In addition to these characteristics, bearings are enhanced with coupling stiffness and damping that serve as resistive forces to movement of the machinery part in a rotation plane. Bearings are supported by all Mechanical analysis types that use the MAPDL solver.

Note • The damping characteristics are not applicable to static, linear buckling, undamped modal, and spectrum analysis systems. • While negative stiffness and/or damping characteristics are allowed in all the supported analysis systems, users are cautioned to ensure its proper use, and check the results carefully. • This boundary condition cannot be applied to a vertex scoped to an End Release.

Scoping Requirements Bearing scoping is limited to only a single face, single edge, single vertex, or an external remote point and only the body-to-ground connection type is allowed. Similar to a spring, there is a Mobile side and Reference side for the bearing connection. The Reference side is assumed to be grounded (or fixed) and the mobile side is set to the scoped entity. Unlike springs, the location of the reference side is set to that of the mobile side because they can be coincident during a linear analysis. For more information about the use of a spring-damper bearing, see COMBI214 — 2D Spring-Damper Bearing in the Mechanical APDL Theory Reference.

Apply Bearing To add a Bearing: 1. Add a Connections folder if one is not already in the tree, by highlighting the Model object and choosing Connections from the Model Context Toolbar (p. 55) or by choosing Insert>Connections from the context menu (right-click). 2. Add a Bearing object by highlighting the Connections folder, opening the Body-Ground drop-down list and then selecting Bearing or by right-clicking on the Connections folder and selecting Insert>Bearing from the context menu. 3. Set the following in the Details view: a. Under the Reference category, specify the Rotation Plane property for your model. Selections include: 632

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Bearings • None (default) • X-Y Plane • Y-Z Plane • X-Z Plane b. Scoping Method as Geometry Selection (default) or Named Selection. The Scoping Method may also be specified to a user-defined Remote Point, if available. c. Connection Behavior as either Rigid (default) or Deformable. If the Bearing is scoped to a Remote Point, the Bearing assumes the Behavior of the Remote Point. The Behavior formulation Coupled is not supported for Bearings. d. Pinball Region as desired. Use the Pinball Region to define where the bearing attaches to face(s), edge(s), or a single vertex if the default location is not desirable. By default, the entire face/edge/vertex is tied to the bearing element. In the event that this is not desirable, you can choose to enter a Pinball Region value. For example, your topology could have a large number of nodes leading to solution processing inefficiencies. Or, if there is overlap between the bearings’s scoped faces and another displacement boundary condition can lead to over-constraint and consequently solver failures.

Note • The Pinball Region and Behavior settings are applicable to underlying bodies that are flexible. • The Pinball Region and Behavior settings are not applicable to a Bearing scoped to the vertex of line body. • A Bearing is classified as a remote boundary condition. Refer to the Remote Boundary Conditions section for a listing of all remote boundary conditions and their characteristics.

The following example illustrates a Bearing on a cylindrical face with customized Details settings.

The stiffness characteristics K11, K22, K12, and K21, and damping characteristics C11, C22, C12, and C21 are used to model four spring-damper sets in a plane of a rotating shaft in this example. For more inRelease 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Connections formation about the spring-damper orientation, see COMBI214 — 2D Spring-Damper Bearing in the Mechanical APDL Theory Reference. The bearing is created on a face of the shaft that is perpendicular to the Z-axis. As the Z-axis is the rotating axis of the shaft, the X-Y Plane is selected for the Rotation Plane option. While the bearing in this example is defined using Global Coordinate System, it can also be defined with a user-defined local coordinate system. When changing from one coordinate system to another, the Bearing needs the scoping to be updated to desired location for the new coordinate system. Note that the coordinates for the Mobile side cannot be modified. The location is read-only. For a bearing to be modeled properly, the location of the mobile side must lie on the rotating axis of the shaft.

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Configuring Analysis Settings The following topics are covered in this section. Analysis Settings for Most Analysis Types Steps and Step Controls for Static and Transient Analyses Analysis Settings for Explicit Dynamics Analyses

Analysis Settings for Most Analysis Types When you define an analysis type, an Analysis Settings object is automatically inserted in the Mechanical application tree. With this object selected, you can define various solution options in the Details view that are customized to the specific analysis type, such as enabling large deflection for a stress analysis. The available control groups as well as the control settings within each group vary depending on the analysis type you have chosen. The sections that follow outline the availability of the control settings for each of these groups and describe the controls available in each group. Step Controls Solver Controls Restart Analysis Restart Controls Creep Controls Cyclic Controls Radiosity Controls Options for Analyses Damping Controls Nonlinear Controls Output Controls Analysis Data Management Rotordynamics Controls Visibility Explicit Dynamics settings are examined in a separate section.

Step Controls Step Controls play an important role in static and transient dynamic analyses. Step controls are used to perform two distinct functions: 1. Define Steps. 2. Specify the Analysis Settings for each step.

Defining Steps See the procedure, Specifying Analysis Settings for Multiple Steps located in the Establish Analysis Settings (p. 134) section. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Configuring Analysis Settings

Specifying Analysis Settings for Each Step The following items can be changed on a per step basis: • Step Controls • Nonlinear Controls • Output Controls

Step Controls The selections available in the Details view for Step Controls group are described below. • Current Step Number: shows the step ID for which the settings in Step Controls, Nonlinear Controls, and Output Controls are applicable. The currently selected step is also highlighted in the bar at the bottom of the Graph window. You can select multiple steps by selecting rows in the data grid or the bars at the bottom of the Graph window. In this case the Current Step Number will be set to multi-step. In this case any settings modified will affect all selected steps.

• Step End Time: shows the end time of the current step number. When multiple steps are selected this will indicate multi-step. • Auto Time Stepping: is discussed in detail in the Automatic Time Stepping (p. 668) section. Automatic time stepping is available for static and transient analyses, and is especially useful for nonlinear solutions. Settings for controlling automatic time stepping are included in a drop down menu under Auto Time Stepping in the Details view. The following options are available: – Program Controlled (default setting): the Mechanical application automatically switches time stepping on and off as needed. A check is performed on non-convergent patterns. The physics of the simulation is also taken into account. The Program Controlled settings are presented in the following table: Auto Time Stepping Program Controlled Settings Analysis Type

Initial Substeps

Minimum Substeps

Maximum Substeps

Linear Static Structural

1

1

1

Nonlinear Static Structural

1

1

10

Linear Steady-State Thermal

1

1

10

Nonlinear Steady-State Thermal

1

1

10

100

10

1000

Transient Thermal

– On: You control time stepping by completing the following fields that only appear if you choose this option. No checks are performed on non-convergent patterns and the physics of the simulation is not taken into account.

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Analysis Settings for Most Analysis Types → Initial Substeps: specifies the size of the first substep. The default is 1. → Minimum Substeps: specifies the minimum number of substeps to be taken (that is, the maximum time step size). The default is 1. → Maximum Substeps: specifies the maximum number of substeps to be taken (that is, the minimum time step size). The default is 10. – Off: no time stepping is enabled. You are prompted to enter the Number Of Substeps. The default is 1. • Define By allows you to set the limits on load increment in one of two ways. You can specify the Initial, Minimum and Maximum number of substeps for a step or equivalently specify the Initial, Minimum and Maximum time step size. • Carry Over Time Step is an option available when you have multiple steps. This is useful when you do not want any abrupt changes in the load increments between steps. When this is set the Initial time step size of a step will be equal to the last time step size of the previous step. • Time Integration is valid only for a Transient Structural or Transient Thermal analysis. This field indicates whether a step should include transient effects (for example, structural inertia, thermal capacitance) or whether it is a static (steady-state) step. This field can be used to set up the Initial Conditions for a transient analysis. – On: default for Transient analyses. – Off: do not include structural inertia or thermal capacitance in solving this step.

Note With Time Integration set to Off in Transient Structural analyses, Workbench does not compute velocity results. Therefore spring damping forces, which are derived from velocity will equal zero. This is not the case for Rigid Dynamics analyses.

Activation/Deactivation of Loads You can activate (include) or deactivate (delete) a load from being used in the analysis within the time span of a step. For most loads (for example, pressure or force) deleting the load is the same as setting the load value to zero. But for certain loads such as specified displacement this is not the case. Activation and deactivation of loads is not available to the Samcef solver.

Note Changing the method of how a multiple-step load value is specified (such as Tabular to Constant), the Activation/Deactivation state of all steps resets to the default, Active. To activate or deactivate a load in a stepped analysis: 1.

Highlight the load within a step in the Graph or a specific step in the Tabular Data window.

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Configuring Analysis Settings 2.

Click the right mouse button and choose Activate/Deactivate at this step!.

Note For displacements and remote displacements, it is possible to deactivate only one degree of freedom within a step. For Temperature, Thermal Condition, Heat Generation, Voltage, and Current loads, the following rules apply when multiple load objects of the same type exist on common geometry selections: • A load can assume any one of the following states during each load step: – Active: Load is active during the first step. – Reactivated: Load is active during the current step, but was deactivated during the previous step. A change in step status exists. – Deactivated: Load is deactivated at the current step, but was active during the previous step. A change in step status exists. – Unchanged: No change in step status exists. • During the first step, an active load will overwrite other active loads that exist higher (previously added) in the tree. • During any other subsequent step, commands are sent to the solver only if a change in step status exists for a load. Hence, any unchanged loads will get overwritten by other reactivated or deactivated loads irrespective of their location in the tree. A reactivated/deactivated load will overwrite other reactivated and deactivated loads that exist higher (previously added) in the tree.

Note For each load step, if both Imported Loads and user-specified loads are applied on common geometry selections, the Imported Loads take precedence. See respective Imported Load for more details. For Imported loads commands are sent to the solver at a load step if the Imported Load: • Is active and has data specified for the current step • Has been reactivated and has data for the current step or at a previous step • Has been deactivated and data was applied at the previous step.

Note For imported loads specified as tables, the data is available outside the range of specified analysis times/frequencies. If the solve time/frequency for a step/sub-step falls outside the specified Analysis Time/Frequency, then the load value at the nearest specified analysis time is used.

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Analysis Settings for Most Analysis Types The tabular data view provides the equation for the calculation of values through piecewise linear interpolation at steps where data is not specified.

Some scenarios where load deactivation is useful are: • Springback of a cantilever beam after a plasticity analysis (see example below). • Bolt pretension sequence (Deactivation is possible by setting Define By to Open for the load step of interest). • Specifying different initial velocities for different parts in a transient analysis. Example: Springback of a cantilever beam after a plasticity analysis In this case a Y displacement of -2.00 inch is applied in the first Step. In the second step this load is deactivated (deleted). Deactivated portions of a load are shown in gray in the Graph and also have a red stop bars indicating the deactivation. The corresponding cells in the data grid are also shown in gray.

In this example the second step has a displacement value of -1.5. However since the load is deactivated this will not have any effect until the third step. In the third step a displacement of -1.5 will be step applied from the sprung-back location.

Solver Controls The properties provided by the Solver Controls category vary based on the specified Analysis Type. This table denotes which Details view properties are supported for each analysis type. The remainder of the section describes the functions and features of the properties.

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Configuring Analysis Settings Analysis Type Static Structural

Details View Properties

RiTrangid sient ModDyStrucal namtural ics

Lin- Steady MagTranear netosient Buck- State statThermal ling Thermal ic

Electric

Thermal Electric

Damped Solver Type Mode Reuse Store Complex Solution Weak Springs Large Deflection Inertia Relief Time Integration and Constraint Stabilization Fracture

Damped — Modal Analyses Only The Damped property is only available for Modal analyses. Set this control to Yes to enable a damped modal system where the natural frequencies and mode shapes become complex. The default setting is No.

Solver Type For Static Structural and Transient Structural analysis types, by default, the Solver Type property is set to Program Controlled, which lets the program select the optimal solver. However you can manually select the Direct or Iterative solver. The Direct option uses the Sparse solver and the Iterative option uses the PCG or ICCG (for Electric and Electromagnetic analyses) solver. See the Help for the EQSLV command in the Mechanical APDL Command Reference for more information about solver selection. For a Modal Analysis, additional Solver Type options are available and include: • Unsymmetric • Supernode • Subspace The Direct, Iterative, Unsymmetric, Supernode, and Subspace types are used to solve a modal system that does not include any damping effects – the Damped property is set to No. By default, the Solver Type property is set to Program Controlled for a Modal Analysis. Except for the Unsymmetric option, the solver types are intended to solve Eigen solutions with symmetric mass and stiffness. For a large model, the Iterative solver is preferred over the Direct solver for its efficiency in terms of solution time and memory usage. During a Modal analysis, the Direct solver uses the Block Lanczos extraction method that employs an automated shift strategy, combined with a Sturm sequence check, to extract the number of eigenvalues requested. The Sturm sequence check ensures that the requested number of eigen frequencies beyond the user supplied shift frequency (FREQB on the MODOPT command) is found without missing any

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Analysis Settings for Most Analysis Types modes. Please see the Block Lanczos help in the Eigenvalue and Eigenvector Extraction section of the Mechanical APDL Theory Reference. The Supernode solver is recommended for extracting a large number of modes. Selecting Supernode as the Solver Type automatically sets the Limit Search to Range property to Yes in the Options category. This selection also displays the Range Minimum and Range Maximum properties and requires a Range Maximum frequency entry. Alternatively, you may reset the Limit Search to Range property to No to find all of the possible modes without any restrictions on the frequency range. Unlike the Direct solver, the Subspace solver doesn’t perform Sturm sequence check by default (STRMCK is OFF by default in SUBOPT command), making it relatively faster than Direct solver and also has reasonable accuracy. In addition, the Subspace solver supports DANSYS allowing you to take advantage of a distributed architecture to perform faster computations. For a Linear Buckling Analysis, the Solver Type options include: Program Controlled, Direct, and Subspace. By default, the Program Controlled option uses the Direct solver. Refer to the BUCOPT command for additional information. For the modal systems with unsymmetric mass and/or stiffness, the Unsymmetric solver is required for solving the Eigen solutions. See the Help for the MODOPT command in the Mechanical APDL Command Reference for more information about solver selection. However, if the Damped property is set to Yes, the Solver Type options include: • Program Controlled • Full Damped • Reduced Damped The default option is Program Controlled. The Reduced Damped solver is preferred over the Full Damped solver for its efficiency in terms of solution time. However, the Reduced Damped solver is not recommended when high damping effects are present because it can become inaccurate.

Mode Reuse — Modal Analyses Only The Mode Reuse property is only available for Modal analyses when you specify the Solver Type as Reduced Damped. This property allows the solver to compute complex eigensolutions efficiently during subsequent solve points by reusing the undamped eigensolution that is calculated at the first solve point. The default setting is Program Controlled. Set this property to Yes to enable it or No to disable the property.

Store Complex Solution — Modal Analyses Only This property is only available for a Modal Analysis and only when the Damped property is set to Yes and the Solver Type is set to Reduced Damped. It allows you to solve and store a damped modal system as an undamped modal system.

Weak Springs For stress or shape simulations, the addition of weak springs can facilitate a solution by preventing numerical instability, while not having an effect on real world engineering loads. The following Weak Springs settings are available in the Details view:

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Configuring Analysis Settings • Program Controlled (default setting): Workbench determines if weak springs will facilitate the solution, then adds a standard weak springs stiffness value accordingly. • On: Workbench always adds a weak spring stiffness. Choosing On causes a Spring Stiffness option to appear that allows you to control the amount of weak spring stiffness. Your choices are to use the standard stiffness mentioned above for the Program Controlled setting of Weak Springs or to enter a customized value. The following situations may prompt you to choose a customized stiffness value: a. The standard weak spring stiffness value may produce springs that are too weak such that the solution does not occur, or that too much rigid body motion occurs. b. You may judge that the standard weak spring stiffness value is too high (rare case). c. You many want to vary the weak spring stiffness value to determine the impact on the simulation. The following Spring Stiffness settings are available: – Program Controlled (default setting): Adds a standard weak spring stiffness (same as the value added for the Program Controlled setting of Weak Springs). – Factor: Adds a customized weak spring stiffness whose value equals the Program Controlled standard value times the value you enter in the Spring Stiffness Factor field (appears only if you choose Factor). For example, setting Spring Stiffness Factor equal to 20 means that the weak springs will be 20 times stronger than the Program Controlled standard value. – Manual: Adds a customized weak spring stiffness whose value you enter (in units of force/length) in the Spring Stiffness Value field (appears only if you choose Manual). • Off: Weak springs are not added. Use this setting if you are confident that weak springs are not necessary for a solution.

Large Deflection This field, applicable to static structural and Transient Structural analyses, determines whether the solver should take into account large deformation effects such as large deflection, large rotation, and large strain. Set Large Deflection to On if you expect large deflections (as in the case of a long, slender bar under bending) or large strains (as in a metal-forming problem). When using hyperelastic material models, you must set Large Deflection On.

Inertia Relief — Linear Static Structural Analyses Only Calculates accelerations to counterbalance the applied loads. Displacement constraints on the structure should only be those necessary to prevent rigid-body motions (6 for a 3D structure). The sum of the reaction forces at the constraint points will be zero. Accelerations are calculated from the element mass matrices and the applied forces. Data needed to calculate the mass (such as density) must be input. Both translational and rotational accelerations may be calculated. This option applies only to the linear static structural analyses. Nonlinearities, elements that operate in the nodal coordinate system, and axisymmetric or generalized plane strain elements are not allowed. Models with both 2D and 3D element types or with symmetry boundary constraints are not recommended. Loads may be input as usual. Displacements and stresses are calculated as usual. Symmetry models are not valid for inertia relief analysis.

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Analysis Settings for Most Analysis Types

Time Integration Type — Transient Analysis of Multiple Rigid Bodies Only This feature is applicable to a Rigid Dynamics analysis. The Time Integration Type feature employs the fourth and fifth order polynomial approximation of the Runge-Kutta algorithm to enable the Mechanical application to integrate the equations of motion during analyses. This feature allows you to choose time integration algorithms and specify whether to use constraint stabilization. The fifth order approximation usually allows for larger time steps and can therefore reduce the total simulation time. The Details view Solver Controls options for the Time Integration Type include: • Time Integration Type field. Available time integration algorithms include: – Runge-Kutta 4 (default setting) — Fourth Order Runge-Kutta – Runge-Kutta 5 — Fifth Order Runge-Kutta • Use Stabilization field. When specified, this option provides the numerical equivalent for spring and damping effects and is proportional to the constraint violation and its time derivative. If there is no constraint violation, the spring and damping has no effect. The addition of artificial spring and damping does not change the dynamic properties of the model. Stabilization options include: – Off — (default setting) — constraint stabilization is ignored. – On — Because constraint stabilization has a minimal impact on calculation time, its use is recommended. When specified, the Stabilization Parameters field also displays. Stabilization Parameters options include: – Program Controlled — valid for most applications. – User Defined — manual entry of spring stiffness (Alpha) and damping ratio (Beta) required.

Note Based on your application, it may be necessary to enter customized settings for Alpha and Beta. In this case, start with small values and use the same value in both fields. Alpha and Beta values that are too small have little effect and values that are too large cause the time step to be too small. The valid values for Alpha and Beta are Alpha > = 0 and Beta > = 0. If Both Alpha and Beta are zero, the stabilization will have no effect.

Fracture For fracture analyses, only one control exists. The Fracture property, which ensures that the effect of cracks are included in the solution, only applies to static structural analysis. It is visible only if the Fracture folder exists in the model. The default setting is On.

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Configuring Analysis Settings

Restart Analysis Note This group is displayed in the Details view only if restart points are available. Restart points can be generated by adjusting the settings in the Restart Controls group. You will also need to set Delete Unneeded Files, under the Analysis Data Management group to No so that restart point files are retained after a solve. The Restart Analysis group is available for the following analysis types: • Static Structural • Transient Structural These control whether to use restart points in subsequent solution restarts. If restart points should be used, Load Step, Substep and Time help reveal the point’s identity in the calculation sequence.

Note When using a modal system database from a version prior to the most current version of Mechanical, it is possible to encounter incompatibility of the file.esav, created by a linked static structural system. This incompatibility can cause the modal system’s solution to fail. In the event you experience this issue, use the Clear Generated Data feature and resolve the static structural system. The Restart Analysis controls are as follows: • Restart Type: By default, Mechanical tracks the state of restart points and selects the most appropriate point when set to Program Controlled. You may choose different restart points by setting this to Manual, however. To disable solution restarts altogether, set it to Off. • Current Restart Point: This option lets you choose which restart point to use. This option is displayed only if Restart Type set to Manual. • Load Step: Displays the Load Step of the restart point to use. If no restart points are available (or all are invalid for a Restart Type of Program Controlled) the display is Initial. • Substep: Displays the Substep of the restart point to use. If no restart points are available (or all are invalid for a Restart Type of Program Controlled) the display is Initial. • Time: Displays the time of the restart point to use.

Restart Controls These control the creation of Restart Points. Because each Restart Point consists of special files written by the solver, restart controls can help you manage the compromise between flexibility in conducting your analyses and disk space usage. Please see the Solution Restarts section for more information about the restart capability and how it relates to Restart Points. The Restart Controls are as follows: • Generate Restart Points: Enables the creation of restart points. 644

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Analysis Settings for Most Analysis Types – Program Controlled: Instructs the program to select restart point generation settings for you. The setting is equivalent to Load Step = Last and Substep = Last. – Manual: Allows you access to the detailed settings for restart point generation. – Off: Restricts any new restart points from being created. • Load Step: Specifies what load steps are to create restart points. Set to All to obtain restart points in all load steps, or to Last to obtain a restart point in the last load step only. • Substep: Specifies how often the restart points are created within a load step. Set to one of the following: – Last to write the files for the last substep of the load step only. – All to write the files for all substeps of the load step. – Specified Recurrence Rate and enter a number N, in the Value field, to generate restart points for a specified number of substeps per load step. – Equally Spaced Points and enter a number N, in the Value field, to generate restart points at equally spaced time intervals within a load step. • Maximum Points to Save Per Step: Specifies the maximum number of files to save for the load step. Choose one of the following options: – Enter 0 to not overwrite any existing files. The maximum number of files for one run is 999. If this number is reached before the analysis is complete, the analysis will continue but will no longer write any files. After 0 is entered, the field will show All. – Enter a positive number to specify the maximum number of files to keep for each load step. When the maximum number has been written for each load step, the first file of that load step will be overwritten for subsequent substeps.

Note If you want to interrupt the solution in a linear transient analysis, by default, the interrupt will be at load step boundaries only (as opposed to nonlinear analyses where interrupts occur at substeps). However, if you want to interrupt a solution to a linear transient analysis on a substep basis, set the following: Generate Restart Controls = Manual, Load Step = All, Substep = All, and Maximum Points to Save Per Step = 1. These settings allow you to accomplish the interrupt on a substep basis without filling up your disk with restart files.

• Retain Files After Full Solve: When restart points are requested, the necessary restart files are always retained for an incomplete solve due to a convergence failure or user request. However, when the solve completes successfully, you have the option to request to either keep the restart points by setting this field to Yes, or to delete them by setting this field to No. You can control this setting here in the Details

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Configuring Analysis Settings view of the Analysis Settings object, or under Tools> Options in the Analysis Settings and Solution preferences list. The setting in the Details view overrides the preference setting.

Note Retain Files After Full Solve has interactions with other controls. Under the Analysis Data Management (p. 664) category, setting Future Analysis to Prestressed forces the restart files to be retained. Similarly, setting Delete Unneeded Files to No implies that restart files are to be retained.

Creep Controls Creep is a rate-dependent material nonlinearity in which the material continues to deform under a constant load. You can perform an implicit creep analysis for a static or transient structural analysis. Creep Controls are available in the Details view of the analysis settings for these two environments only after you have selected a creep material for at least one prototype in the analysis. The Creep Controls group is available for the following analysis types: • Static Structural • Transient Structural Creep controls are step-aware, meaning that you are allowed to set different creep controls for different load steps in a multistep analysis. If there were multiple load steps in the analysis before you chose the creep material, then choosing the creep material will set the Creep Controls properties to their default value. The Creep Controls group includes the following properties: • Creep Behavior — The default value is Off for the first load step and On for all the subsequent load steps. You may change it according to your analysis. • Creep Limit Ratio (available only if Creep Behavior is set to On) — This property issues the Mechanical APDL CUTCONTROL command with your input value of creep limit ratio. (Refer to the CUTCONTROL command description for details). The default value of Creep Limit Ratio is 1. You are allowed to pick any non-negative value.

Cyclic Controls The Harmonic Index Range setting within the Cyclic Controls category is only used in a Modal analysis that involves cyclic symmetry to specify the solution ranges for the harmonic index. The setting appears if you have defined a Cyclic Region for this analysis. • The Program Controlled option solves all applicable harmonic indices.

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Analysis Settings for Most Analysis Types • The Manual option exposes additional fields that allow you to specify a range of harmonic indices for solution from the Minimum value to the Maximum value in steps of the Interval value.

Note Static Structural cyclic symmetry solutions always use all harmonic indices required for the applied loads.

Radiosity Controls The Radiosity Controls group is available for the following analysis types: • Steady — State Thermal • Transient Thermal • Thermal Electric The following settings within the Radiosity Controls category are used in conjunction with the Radiation boundary condition when defining surface-to-surface radiation for thermal related analyses that use the ANSYS solver. These settings are based on the RADOPT command in Mechanical APDL. • Radiosity Solver • Flux Convergence • Maximum Iteration • Solver Tolerance (dependent upon the unit of measure) • Over Relaxation For the Radiosity Solver property, selections include the Gauss-Seidel iterative solver (Program Controlled default), the Direct solver, or the Iterative Jacobi solver.

View Factors for 3D Geometry For 3D geometry, the Hemicube Resolution setting is also available based on the HEMIOPT command in Mechanical APDL. See the View Factor Calculation (3-D): Hemicube Method section in the Mechanical APDL Theory Reference for further information.

View Factors for 2-D Geometry For 2–D geometry, the following settings are available and are based on the V2DOPT command in Mechanical APDL: • View Factor Method • Number of Zones • Axisymmetric Divisions See the following sections of the Mechanical APDL help for further information on these settings:

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Configuring Analysis Settings • Using the Radiosity Solver Method in the Thermal Analysis Guide. • Mechanical APDL Theory Reference sections: – Non-Hidden Method – Hidden Method – View Factors of Axisymmetric Bodies

Options for Analyses An Options control group is included in the Analysis Settings Details view for the following analysis types only: • Modal • Harmonic • Transient Structural • Linear Buckling • Random Vibration • Response Spectrum

Modal Analysis Options Group For Modal analyses, the Options group includes the following controls: Max Modes to Find Specifies the number of natural frequencies to solve for in a modal analysis. Limit Search Range Allows you to specify a frequency range within which to find the natural frequencies. The default is set to No. If you set this to Yes, you can enter a minimum and maximum frequency value. If you specify a range the solver will strive to extract as many frequencies as possible within the specified range subject to a maximum specified in the Max Modes to Find field.

Harmonic Analysis Options Group The Options group controls for Harmonic analyses are described below. Frequency Sweep Range This is set by defining the Range Minimum and Range Maximum values under Options in the Details view. Solution Intervals This sets the number of the solution points between the Frequency Sweep Range. You can request any number of harmonic solutions to be calculated. The solutions are evenly spaced within the specified frequency range, as long as clustering is not active. For example, if you specify 10 solutions in the range 30 to 40 Hz, the program will calculate the response at 31, 32, 33, …, 39, and 40 Hz. No response is calculated at the lower end of the frequency range.

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Analysis Settings for Most Analysis Types Solution Method Three solution methods are available to perform harmonic analysis: Mode Superposition method, Direct Integration (Full) method, and the Variational Technology method.

Mode Superposition Method Mode Superposition is the default method, and generally provides results faster than the Full method. In the Mode Superposition method a modal analysis is first performed to compute the natural frequencies and mode shapes. Then the mode superposition solution is carried out where these mode shapes are combined to arrive at a solution.

Modal Frequency Range Specifies the range of frequencies over which mode shapes will be computed in the modal analysis: • Program Controlled: The modal sweep range is automatically set to 200% of the upper harmonic limit and 50% of the lower harmonic limit. This setting is adequate for most simulations.

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Configuring Analysis Settings • Manual: Allows you to manually set the modal sweep range. Choosing Manual displays the Modal Range Minimum and Modal Range Maximum fields where you can specify these values. Include Residual Vector This property is available for a Harmonic Analysis Using Linked Modal Analysis System. It can be turned On to execute the RESVEC command and calculate or include residual vectors. The default setting is Off. Please see the RESVEC command in the Mechanical APDL Command Reference for additional information. Cluster Results and Cluster Number (Mode Superposition only) This option allows the solver to automatically cluster solution points near the structure’s natural frequencies ensuring capture of behavior near the peak responses. This results in a smoother, more accurate response curves. Cluster Number specifies the number of solutions on each side of a natural frequency. The default is to calculate four solutions, but you may specify any number from 2 to 20. Options: • Solution Method = Mode Superposition • Cluster Number = Yes Solution Intervals = 15: Here 15 solutions are evenly spaced within the frequency range. Note how the peak can be missed altogether.

Cluster = 5: Here 5 solutions are performed automatically on either side of each natural frequency capturing the behavior near the peaks.

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Analysis Settings for Most Analysis Types

Store Results At All Frequencies Upon solution, harmonic environments store data specified in the Output Controls for all intervals in the frequency range. Consequently, seeking additional results at new frequencies will no longer force a solved harmonic environment to be resolved. This choice will lead to a better compromise between storage space (results are now stored in binary form in the RST file) and speed (by reducing the need to resort to the solver to supply new results). If storage is an issue, set the Store Results At All Frequencies to No. The application retains minimal data with this setting, providing only the harmonic results requested at the time of solution. As a result, the Output Controls do not control the availability of the results. This option is especially useful for Mode Superposition harmonic response analyses with frequency clustering. It is unavailable for harmonic analyses solved with the Full method.

Note With this option set to No, the addition of new frequency or phase responses to a solved environment requires a new solution. Adding a new contour result of any type (stress or strain) or a new probe result of any type (reaction force, reaction moment, or bearing) for the first time on a solved environment requires you to solve, but adding additional contour results or probe results of the same type does not share this requirement; data from the closest available frequency is displayed (the reported frequency is noted on each result). Note that the values of frequency, type of contour results (displacement, stress, or strain) and type of probe results (reaction force, reaction moment, or bearing) at the moment of the solution determine the contents of the result file and the subsequent availability of data. Planning these choices can significantly reduce the need to resolve an analysis. Full Method (Direct Integration) The Full method uses the full system matrices for the solution calculations. It is more thorough but also requires greater processing time and capability.

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Configuring Analysis Settings

The property Variational Technology displays when Full is specified. This option is an alternate Solution Method that is based on the harmonic sweep algorithm of the Full method. The options include: • Program Controlled (default setting) — the application selects the most efficient method (Full or Variational Technology). • Yes — Specifies that the Variational Technology method is used. • No — Specifies that the Full method is used. For additional information, see Harmonic Analysis Variational Technology Method, and Variational Technology, as well as the HROPT command in the Command Reference.

Transient Structural Options Group Include Residual Vector Include Residual Vector is the only Options group property for a Transient Structural Analysis Using Linked Modal Analysis System. It can be turned On to execute the RESVEC command and calculate or include residual vectors. The default setting is Off. Please see the RESVEC command in the Mechanical APDL Command Reference for additional information.

Linear Buckling Options Group For Linear Buckling analyses, the Options group contains the Max Modes to Find control. You need to specify the number of buckling load factors and corresponding buckling mode shapes of interest. Typically only the first (lowest) buckling load factor is of interest.

Random Vibration Options Group For Random Vibration analyses, the Options group includes the following controls. Number of Modes to Use Specifies the number of modes to use from the modal analysis. A conservative rule of thumb is to include modes that cover 1.5 times the maximum frequency in the PSD excitation table.

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Analysis Settings for Most Analysis Types Exclude Insignificant Modes When set to Yes, allows you to not include modes for the mode combination as determined by the threshold value you set in the Mode Significant Level field. The default value of 0 means all modes are selected (same as setting Exclude Insignificant Modes to No) while a value of 1 means that no modes are selected. The higher the threshold is set, the fewer modes are selected for mode combination.

Response Spectrum Options Group For Response Spectrum analyses, the Options group includes the following controls. Number of Modes to Use Specify the number of modes to use from the modal analysis. It is suggested to have modes that span 1.5 times the maximum frequency defined in input excitation spectrum. Spectrum Type Specify either Single Point or Multiple Points. If two or more input excitation spectrums are defined on the same fixed degree of freedoms, use Single Point, otherwise use Multiple Points. Modes Combination Type Specify a method to be used for response spectrum calculation. Choices are SRSS, CQC, and ROSE. In general, the SRSS method is more conservative than the other methods. The SRSS method assumes that all maximum modal values are uncorrelated. For a complex structural component in three dimensions, it is not uncommon to have modes that are coupled. In this case, the assumption overestimates the responses overall. On the other hand, the CQC and the ROSE methods accommodate the deficiency of the SRSS by providing a means of evaluating modal correlation for the response spectrum analysis. Mathematically, the approach is built upon random vibration theory assuming a finite duration of white noise excitation. The ability to account for the modes coupling makes the response estimate from the CQC and ROSE methods more realistic and closer to the exact time history solution.

Damping Controls The controls of the Damping Controls group vary based on the type of analysis being performed. Supported analysis types include: • Transient Structural • Harmonic • Random Vibration/Response Spectrum The following forms of damping are available in the application: • Constant Damping. This property is available for Random Vibration analyses. The default setting is Program Controlled. You may also set the property to Manual. • Constant Damping Ratio. This specifies the amount of damping in the structure as a percentage of critical damping. If you set this in conjunction with the Stiffness Coefficient, and Mass Coefficient, the effects are cumulative. You define the Constant Damping Ratio in the Details view of the Analysis Settings object. The Constant Damping Ratio can also be specified in Engineering Data. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Configuring Analysis Settings For a Random Vibration analysis, this property defaults to 0.01 (1%). Set the Constant Damping property to Manual to specify the value. • Stiffness Coefficient Defined By. Define the Stiffness Coefficient by entering a value, Direct, or by entering a Frequency and a Damping Ratio, Damping vs. Frequency. • Stiffness Coefficient (Beta Damping, β). A coefficient value that is used to define a Beta damping by multiplying it with stiffness. You can enter the value directly or the value can be computed from a damping ratio at a specified frequency. You define a Stiffness Coefficient in the Details view of the Analysis Settings object. The Beta Damping can also be specified in Engineering Data. Refer to the BETAD command in the Mechanical APDL Command Reference for more information about the Beta Damping Factor. • Frequency. Visible when Stiffness Coefficient Defined By is set to Damping vs. Frequency. • Damping Ratio. Visible when Stiffness Coefficient Defined By is set to Damping vs. Frequency. The value of β is not generally known directly, but is calculated from the modal damping ratio, ξi. ξi is the ratio of actual damping to critical damping for a particular mode of vibration, i. If ωi is the natural circular frequency, then the beta damping is related to the damping ratio as β = 2 ξi/ωi . Only one value of β can be input in a step, so choose the most dominant frequency active in that step to calculate β. • Mass Coefficient (Alpha Damping Factor, α). A coefficient that is used to define an Alpha damping by multiplying it with mass. Beta and Alpha damping factors are collectively called Rayleigh damping. The Alpha Damping can also be specified in Engineering Data. Refer to the ALPHAD command in the Mechanical APDL Command Reference for more information about the Alpha Damping Factor. • Numerical Damping. Also referred to as amplitude decay factor (γ), this option controls the numerical noise produced by the higher frequencies of a structure. Usually the contributions of these high frequency modes are not accurate and some numerical damping is preferable. A default value of 0.1 is used for Transient Structural analysis and a default value of 0.005 is used for Transient Structural analysis using a linked Modal analysis system. To change the default, change the Numerical Damping field in the Details view of the Analysis Settings object to Manual from Program Controlled, which allows you to enter a custom value in the Numerical Damping Value field. • Material Damping: there are two types of material-based damping, Material Dependent Damping and Constant Damping Coefficient. Material Dependent Damping consists of beta damping and alpha damping. These are defined as material properties in Engineering Data. • Element Damping: Spring damping and Bearing damping are defined in the Details view of the Spring object and Bearing object. You can specify more than one form of damping in a model. In addition to structural damping and material damping, the model can have damping from spring and bearing connection, namely Element

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Analysis Settings for Most Analysis Types Damping (see above). The application formulates the damping matrix as the sum of all the specified forms of damping.

Note Restrictions of applying damping in each analysis type can be found in Damping section of the MADPL Structural Analysis Guide.

Nonlinear Controls This section describes the properties provided by Nonlinear Controls category. The properties of this category vary based on analysis type. The subsections listed here describe the Nonlinear Controls properties for each supported analysis type. • Nonlinear Controls for Steady-State, Static, and Transient Structural Analyses • Nonlinear Controls for Transient Thermal Analyses • Nonlinear Controls for Rigid Dynamics Analyses

Nonlinear Controls for Steady-State, Static, and Transient Analyses This topic examines the Nonlinear Controls as they apply to Steady-State, Static, and Transient Structural Analyses, which include Electric, Magnetostatic, Static Structural, Transient Structural, Steady-State Thermal, and Thermal-Electric analyses. Newton-Raphson Option For nonlinear Static Structural and Full Transient Structural analysis types, the Newton-Raphson Option property is available. This property allows you to specify how often the stiffness matrix is updated during the solution process. Newton-Raphson Option property options include: • Program Controlled (default setting) • Full • Modified • Unsymmetric The Program Controlled option allows the program to select the Newton-Raphson Option setting based on the nonlinearities present in your model. For more information about the additional options, see the Newton-Raphson Option section in the Mechanical APDL Structural Analysis Guide. If you experience convergence difficulties, switching to an Unsymmetric solver may aid in Convergence. Convergence Criterion When solving nonlinear steady-state, static, or transient analyses, an iterative procedure (equilibrium iterations) is carried out at each substep. Successful solution is indicated when the out-of-balance loads are less than the specified convergence criteria. Criteria appropriate for the analysis type and physics are displayed in this grouping. Convergence controls are “step aware”. This means that the setting can be different for each step. The following convergence criteria properties are available: Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Configuring Analysis Settings • Electric analysis: Voltage Convergence and Current Convergence. • Magnetostatic analysis: CSG Convergence and AMP Convergence. • Static Structural analysis and Transient Structural analysis: Force Convergence, Moment Convergence, Displacement Convergence, and Rotation Convergence. • Steady-State Thermal analysis: Heat Convergence and Temperature Convergence. • Thermal-Electric analysis: Heat Convergence, Temperature Convergence, Voltage Convergence, and Current Convergence. The following convergence controls are available for each of these properties: • Program Controlled (default setting): The application sets the convergence criteria. • On: You specify that a convergence criterion is activated. Once activated, additional properties become available and include: – Value: This is the reference value that the solver uses to establish convergence. The recommended and program controlled setting, Calculated by solver, automatically calculates the value based on external forces, including reactions, or you can input a constant value. When Temperature Convergence is set to On, the Value field provides a drop-down menu with the options Calculated by solver or User Input. Selecting User Input displays an Input Value field you use to enter a value. When any other convergence property is set to On, selecting the Calculated by solver field allows you to manually enter a value. – When any other convergence is set to On, simply clicking on the Calculated by solver field allows you to add a value that replaces the Calculated by solver display. – Tolerance times Value determines the convergence criterion – Minimum Reference: This is useful for analyses where the external forces tend to zero. This can happen, for example, with free thermal expansion where rigid body motion is prevented. In these cases the larger of Value or Minimum Reference will be used as the reference value. • Remove: Indicates that an attempt will be made to remove this criterion during the solution. At least one other convergence criterion must be turned On to allow the Remove criterion to execute.

Note You may activate Displacement/Rotation convergence by the Mechanical APDL solver arbitrarily for highly nonlinear problems, even though you explicitly removed this option by choosing Remove from the drop-down menu. If for some reasons, you want to override this default behavior, it is important to turn on Force/Moment convergence and then try choosing Remove on Displacement/Rotation convergence. If you do not want any convergence options to be turned on, then you may try setting the solution controls to off, using a «Commands Objects» (p. 1141) object. Line Search

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Analysis Settings for Most Analysis Types Line search can be useful for enhancing convergence, but it can be expensive (especially with plasticity). You might consider setting Line Search on in the following cases: • When your structure is force-loaded (as opposed to displacement-controlled). • If you are analyzing a «flimsy» structure which exhibits increasing stiffness (such as a fishing pole). • If you notice (from the program output messages) oscillatory convergence patterns.

Note The Line Search control is “step aware” and can be different for each step. Stabilization Convergence difficulty due to an unstable problem is usually the result of a large displacement for small load increments. Nonlinear stabilization technique can help achieve convergence. Nonlinear stabilization can be thought of as adding artificial dampers to all of the nodes in the system. Any degree of freedom that tends to be unstable has a large displacement causing a large damping/stabilization force. This force reduces displacements at the degree of freedom so stabilization can be achieved. There are three Keys for controlling nonlinear stabilization: • Off — Deactivate stabilization (default setting). • Constant — Activate stabilization. The energy dissipation ratio or damping factor remains constant during the load step. • Reduce — Activate stabilization. The energy dissipation ratio or damping factor is reduced linearly to zero at the end of the load step from the specified or calculated value. There are two options for the Method property for stabilization control: • Energy — Use the energy dissipation ratio as the control (default setting). • Damping — Use the damping factor as the control. When Energy is specified, an Energy Dissipation Ratio needs to be entered. The energy dissipation ratio is the ratio of work done by stabilization forces to element potential energy. This value is usually a number between 0 and 1. The default value is 1.0e-4. When Damping is specified, a Damping Factor value needs to be entered. The damping factor is the value that the ANSYS solver uses to calculate stabilization forces for all subsequent substeps. This value is greater than 0.

Note The Damping Factor value is dependent on the active unit system and may influence the results if unit systems are changed. You may wish to use an initial trial value from a previous run for this entry (such as a run with the Energy Dissipation Ratio as input). See the Controlling the Stabilization Force section of the Mechanical APDL Structural Analysis Guide for additional information.

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Configuring Analysis Settings There are three options for Activation For First Substep control: • No — Stabilization is not activated for the first substep even when it does not converge after the minimal allowed time increment is reached (default setting). • On Nonconvergence — Stabilization is activated for the first substep if it still does not converge after the minimal allowed time increment is reached. Use this option for the first load step only. • Yes — Stabilization is activated for the first substep. Use this option if stabilization was active for the previous load step Key = Constant. For Stabilization Force Limit, a number between 0 and 1 should be specified. The default value is 0.2. To omit a stabilization force check, set this value to 0. Refer to Unstable Structures in the Mechanical APDL Structural Analysis Guide for assistance with using the stabilization options listed above.

Nonlinear Controls for Transient Thermal Analyses Nonlinear Formulation The Nonlinear Formulation category controls how nonlinearities are to be handled for the solution. The following options are available: • Program Controlled (default) — Mechanical automatically chooses between the Full or Quasi setting as described below. The Quasi setting is based on a default Reformulation Tolerance of 5%. The Quasi option is used by default, but the Full option is used in cases when a Radiation load is present. • Full — Manually sets formulation for a full Newton-Raphson solution. • Quasi — Manually sets formulation based on a tolerance you enter in the Reformulation Tolerance field that appears if Quasi is chosen.

Nonlinear Controls for Rigid Dynamics Analyses Relative Assembly Tolerance Allows you to specify the criterion for determining if two parts are connected. Setting the tolerance can be useful in cases where initially, parts are far enough away from one another that, by default, the program will not detect that they are connected. You could then increase the tolerance as needed. Energy Accuracy Tolerance This is the main driver to the automatic time stepping. The automatic time stepping algorithm measures the portion of potential and kinetic energy that is contained in the highest order terms of the time integration scheme, and computes the ratio of the energy to the energy variations over the previous time steps. Comparing the ratio to the Energy Accuracy Tolerance, Workbench will decide to increase or decrease the time step. See the Rigid Dynamics Analysis (p. 216) section for more information.

Output Controls The controls of the Output Controls group vary based on the type of analysis being performed. Supported analysis types include: • Static Structural 658

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Analysis Settings for Most Analysis Types • Transient Structural • Harmonic • Modal • Linear Buckling • Random Vibration/Response Spectrum • Steady — State Thermal • Transient Thermal • Electric • Thermal Electric Output Controls give you the ability to specify which type of quantities are written to the result file for use during post-processing. As a result, you can control the size of the results file which can be beneficial when performing a large analysis. The following Output Controls are available in the Details view to be activated (Yes) or not (No) and included or not included in the results file. • Stress. Writes element nodal stresses to the results file. The default value is Yes. Available for Static Structural, Transient Structural, Modal, and Linear Buckling analysis types. • Strain. Writes element elastic strains to the results file. The default value is Yes. Available for Static Structural, Transient Structural, Modal, and Linear Buckling analysis types. • Nodal Forces. Writes elemental nodal forces to the results file. Options include: – No (default setting): No nodal forces are written to the results file. – Yes: This option writes nodal forces for all nodes. It is available for Static Structural, Transient Structural, Harmonic, and Modal analysis types. This Output Control must be set to Yes if you want to use the MAPDL Command NFORCE, FSUM in Mechanical (via command snippets) because those MAPDL commands will access nodal force records in the result file as well as to obtain Reactions on the underlying source or target element. – Constrained Nodes. This option writes nodal forces for constrained nodes only. It is available for Mode Superposition (MSUP) Harmonic and Transient analyses that are linked to a Modal Analysis with the Expanded Results From option set to the Modal Analysis. This option directs Mechanical to use only the constrained nodes when calculating reaction forces and moments. The advantage is a reduced results file size. • Calculate Reactions. Turn On for Nodal Forces on constraints. Available for Modal, Harmonic, and Transient (applicable only when linked to a Modal analysis.) analysis types. • Calculate Thermal Flux. Available for Steady-State Thermal and Transient Thermal analysis types. • Keep Modal Results. Available for Random Vibration analyses only. The default value is No. This setting removes modal results from the result file in an effort to reduce file size. Setting this property to Yes allows you to perform post-processing on results of the Random Vibration solution (e.g., Response PSD) via command snippets. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Configuring Analysis Settings • Calculate Velocity. Writes Velocity to the results file. Available for Response Spectrum and Random Vibration analysis types. The default value is No for Response Spectrum and Yes for Random Vibration analysis. • Calculate Acceleration. Writes Acceleration to the results file. Available for Response Spectrum and Random Vibration analysis types. The default value is No for Response Spectrum and Yes for Random Vibration analysis. • Contact Miscellaneous. Turn On if Contact Based Force Reactions are desired. The default value is No. Available for Static and Transient Structural analysis types. Not Available when linked to a Modal analysis. • General Miscellaneous. Used to access element miscellaneous records via SMISC/NMISC expressions for user defined results. The default value is No.

Note To ensure that Membrane and Bending Stress results are not under-defined, set this option to Yes.

• Store Modal Results. Available for Modal analyses only. This field is displayed only when Stress and/or Strain are set to Yes, implying that stress and strain results are to be expanded and saved to file.mode, in addition to displacement results (mode shapes). Depending on the downstream linked analysis, you may want to save these modal stress and/or modal strain results, which are linearly superimposed to get the stress and/or strain results of the downstream linked analysis. This reduces computation time significantly in the downstream linked analysis because no modal stress and/or modal strain results are expanded again. The following options are available: – Program Controlled (default setting): Let the program choose whether or not the modal results are saved for possible downstream analysis. – No: Stress and strain results are not saved to file.mode for later use in the downstream linked analyses. This option is recommended for the linked harmonic analysis due to load generation, which requires that stresses and/or strains are expanded again as a result of the addition of elemental loads in the linked harmonic analysis. – For Future Analysis: Stress and strain results are saved to file.mode for later use in the downstream linked analyses. This option is recommended for a linked random vibration analysis. Choosing this option improves the performance and efficiency of the linked random vibration analysis because, with no load, there is no need for stress and strain expansion. • Expand Results From. – Linked Harmonic analyses. This field is displayed only when Stress and/or Strain and/or Calculate Reactions are set to Yes, implying that stress, strain, and reaction results are to be expanded and saved to file.mode after the load generation. Depending on the number of modes and number of frequency steps, you may want to save these modal stresses and/or strains after the load generation, which can be linearly superimposed to obtain harmonic stresses and/or strains at each frequency step. The following options are available: → Program Controlled (default setting): Let the program choose whether or not the stress, strain, and reaction results are expanded and saved for possible downstream analysis. When the Program Controlled option is chosen, one more read-only Details view entry (Expansion) will be shown. This in-

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Analysis Settings for Most Analysis Types dicates whether the stress, strain and reaction results are expanded from the modal solution or harmonic solution. → Harmonic Solution: Stress, strain, and reaction results are not expanded nor saved to file.mode after the load generation in the linked harmonic system. This option is recommended when the number of frequency steps is far less than the number of modes. In this option, the stress, strain, and/or reaction results are expanded from harmonic displacement at each frequency step. In this case, stress, strain, and/or reaction expansion is performed as many times as the number of frequency steps. → Modal Solution: Stress, strain, and reaction results are expanded and saved to file.mode after the load generation in the linked harmonic system. This option is recommended when the number of frequency steps is far more than the number of modes. In this option, the stress, strain, and/or reaction results are calculated by linearly combining the modal stresses, modal strains, and/or modal reactions expanded after the load generation. In this case, stress, strain, and/or reaction expansion are performed as many times as the number of modes. Refer to Recommended Settings for Modal and Linked Analysis Systems (p. 662) for further details. – Linked Transient analyses. This field is displayed only when Calculate Stress and/or Calculate Strain are set to Yes, implying that stress, strain and reaction results are to be expanded and saved to file.mode after the load generation. Depending on the number of modes and total number of sub steps/ time steps, you may want to save these modal stresses and/or strains after the load generation, which can be linearly superimposed to obtain transient stresses and/or strains at each time step. The following options are available: → Program Controlled (default setting): Let the program choose whether or not the stress and strain results are expanded and saved for possible downstream analysis. When the program controlled option is chosen, one more read only details view entry — — Expansion will be shown. This indicates whether the stress and strain results are expanded from modal solution or transient solution. → Transient Solution: Stress and strain results are not expanded nor saved to file.mode after the load generation in the linked transient analysis system. This option is recommended when the number of time steps accumulated over all the load steps is far less than the number of modes. In this option, the stress and/or strain results are expanded from transient displacement at each time step. In this case, stress and/or strain expansion is performed as many times as the number of time steps. → Modal Solution: Stress and strain results are expanded and saved to file.mode after the load generation in the linked transient system. This option is recommended when the number of time steps accumulated over all the load steps is far more than the number of modes. In this option, the stress and/or strain results are calculated by linearly combining the modal stresses and/or modal strains expanded after the load generation. In this case, stress and/or strain expansion are performed as many times as the number of modes. Refer to Recommended Settings for Modal and Linked Analysis Systems (p. 662) for further details.

Note • It is recommended that you not change Output Controls settings during a Solution Restart. Modifying Output Controls settings change the availability of the respective result type in the results file. Consequently, result calculations cannot be guaranteed for the entire solution. In addition, Result file values may not correspond to GUI settings in this scenario. Settings turned

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Configuring Analysis Settings off during a restart generate results equal to zero and may affect post processing of results and are therefore unreliable. • Modification of Stress, Strain, Nodal Force, Contact Miscellaneous, and General Miscellaneous will not invalidate the solution. If you want these output controls setting modification to be incorporated to your solution, please clean the solution first.

The above output controls are not step-aware, meaning that the settings are constant across multiple steps. In addition, the following settings are step-aware and allow you to define when data is calculated and written to the result file for Static Structural, Transient Structural, Rigid Dynamics, Steady-State thermal, and Transient Thermal analyses: • Store Results At. Specify this time to be All Time Points (default setting), Last Time Point, Equally Spaced Points or Specified Recurrence Rate. • Value. Displayed only if Store Results At is set to Equally Spaced Points or Specified Recurrence Rate. The controls that define when data is calculated are step aware, meaning that the settings can vary across multiple steps.

Recommended Settings for Modal and Linked Analysis Systems The following table provides a summary of recommended settings for Store Modal Results and Expand Results From based on the analysis type. Analysis Type

Recommended Store Modal Results Settings

Recommended Expand Results From Settings

Modal with no downstream linked analysis

No

Not available.

Modal with downstream linked Harmonic analysis

Stress and strain results not needed to be saved to file.mode because there is no downstream analysis. No

Harmonic Solution

Stress and strain results from modal analysis are overwritten by stresses and strains which are expanded again in the linked harmonic analysis due to any loads added in the downstream analysis.

Use when number of frequency steps are far less than the number of modes. This option is not available when the Modal analysis is Pre-Stress. Modal Solution Use when number of frequency steps are far more than the number of modes. This is the only option available when the Modal analysis is Pre-Stress.

Modal with downstream linked Ran662

For Future Analysis

Not available.

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Analysis Settings for Most Analysis Types Analysis Type

Recommended Store Modal Results Settings

dom Vibration analysis

Stress and strain results from modal analysis are expanded and used in the linked random vibration analysis. No stress or strain expansion is needed again because there is no load.

Modal with downstream linked Response Spectrum analysis

No

Recommended Expand Results From Settings

Not available.

Stress and strain results are always combined in response spectrum analysis using file.rst and file.mcom.

Note To evaluate summation of element nodal forces using FSUM in Command Snippet, it is required to save element nodal forces in modal to file.mode. Modal with downstream linked Transient analysis

No

Transient Solution

Stress and strain results from modal analysis are overwritten by stresses and strains which are expanded again in the linked transient analysis due to any loads added in the downstream analysis.

Use when number of time steps accumulated over all the load steps is far less than the number of modes. This option is not available when the Modal Analysis is Pre-Stress. Modal Solution Use when number of time steps accumulated over all the load steps is far more than the number of modes. This is the only option available when the Modal Analysis is PreStress.

Limitations When Using the Mechanical APDL Solver • The Mechanical application cannot post process split result files produced by the ANSYS solver. Try either of the following workarounds should this be an issue: – Use Output Controls to limit the result file size. Also, the size can more fully be controlled (if needed) by inserting a Commands object for the OUTRES command.

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Configuring Analysis Settings – Increase the threshold for the files to be split by inserting a Commands object for the /CONFIG,FSPLIT command.

Analysis Data Management The controls of the Analysis Data Management group vary based on the type of analysis being performed. Supported analysis types include: • Static Structural • Transient Structural • Rigid Dynamics • Harmonic • Modal • Linear Buckling • Random Vibration/Response Spectrum • Steady — State Thermal • Transient Thermal • Magnetostatic • Electric • Thermal Electric This grouping describes the options and specifications associated with the solution files. • Solver Files Directory: Indicates the location of the solution files for this analysis. The directory location is automatically determined by the program as detailed in File Management in the Mechanical Application (p. 1070). For Windows users, the solution file folder can be displayed using the Open Solver Files Directory feature. – Open Solver Files Directory Feature → This right-click context menu option is available when you have an analysis Environment or a Solution object selected. → Once executed, this option opens the operating system’s (Windows Only) file manager and displays the directory that contains the solution files for your analysis. → The directory path is shown in the Details View. If a solution is in progress, the directory is shown in the Solver Files Directory field. When a solution is in progress, the directory displays in the Scratch Solver Files Directory. For a remote solve, it will open the scratch directory until the results download is complete. → This option is available on the Windows platform only.

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Analysis Settings for Most Analysis Types • Future Analysis: This property defines whether to use the results of the current analysis as loading or as an initial condition in a subsequent analysis. Shown below are the analysis types and their supported subsequent analysis choices. – Static Structural: options include None or Prestressed Analysis. If you link the supported analysis types, this property automatically defaults to the Prestressed Analysis setting. A Static Structural analysis can provide Pre-Stress effects for the following analysis types: → Pre-Stressed (Full) Harmonic Response → Pre-Stressed Modal – Linear Buckling: a Static Structural analysis is a prerequisite. – Modal: options include None or MSUP Analyses. When linked to a supported analysis type, as shown below, this property automatically defaults to the MSUP Analyses setting. A Modal analysis is a prerequisite for the following analysis types: → Random Vibration (PSD) → Response Spectrum • Scratch Solver Files Directory: This is a read-only indication of the directory where a solve “in progress” occurs. All files generated after the solution is done (including but not limited to result files) are then moved to the Solver Files Directory. The files generated during solves on My Computer or files requested from RSM for postprocessing during a solve remain in the scratch directory. For example, an early result file could be brought to the scratch folder from a remote machine through RSM during postprocessing while solving. With the RSM method, the solve may even be computed in this folder (for example, using the My Computer, Background SolveProcess Settings). The Mechanical application maintains the Scratch Solver Files Directory on the same disk as the Solver Files Directory. The scratch directory is only set for the duration of the solve (with either My Computer or My Computer, Background). After the solve is complete, this directory is set to blank. The use of the Scratch Solver Files Directory prevents the Solver Files Directory from ever getting an early result file. • Save MAPDL db: No (default setting) / Yes. Some Future Analysis settings will require the db file to be written. In these cases this field will be set to Yes automatically. • Delete Unneeded File: Yes (default setting) / No. If you prefer to save all the solution files for some other use you may do so by setting this field to No. • Nonlinear Solutions: Read only indication of Yes / No depending on presence of nonlinearities in the analysis. • Solver Units: You can select one of two options from this field: – Active System — This instructs the solver to use the currently active unit system (determined via the toolbar Units menu) for the very next solve. – Manual — This allows the you to choose the unit system for the solver to use by allowing them access to the second field, «Solver Unit System». Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Configuring Analysis Settings • Solver Units System: – If Active System is chosen for the Solver Units field, then this field is read-only and displays the active system. – If Manual is chosen for the Solver Units field, this field is a selectable drop-down menu. – If a Magnetostatic analysis is being performed, the field is read only because the only system available to solve the analysis is the mks system. – If a Thermoelectric or Electric analysis is being performed, only mks and µmks systems can be selected because they are the only systems currently allowed for these analyses.

Rotordynamics Controls The controls of the Rotordynamics Controls group vary based on the type of analysis being performed. Supported analysis types include: • Transient Structural • Harmonic • Modal The following settings control the items that apply to a rotating structure in a Modal Analysis. • Coriolis Effect — Set to On if Coriolis effects should be applied. On is a valid choice only if the Damped Solver Control is Yes. The default is Off. • Campbell Diagram — Set to On if Campbell diagram is to be plotted. The default is Off. On is a valid choice only if Coriolis Effect is turned On. • Number of Points — Indicates the number of solve points for the Campbell diagram. The default value is 2. A minimum of two (2) solve points is necessary. This property is only displayed when Campbell Diagram is set to On.

Visibility Allows you to selectively display loads in the Graph window by choosing Display or Omit for each available load type. A load must first be applied before the Visibility group becomes available/shown under Analysis Settings. The Visibility group is available for the following analysis types: • Static Structural • Transient Structural • Steady — State Thermal • Transient Thermal

Steps and Step Controls for Static and Transient Analyses The following topics are covered in this section: 666

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Steps and Step Controls for Static and Transient Analyses Role of Time in Tracking Steps, Substeps, and Equilibrium Iterations Automatic Time Stepping Guidelines for Integration Step Size

Role of Time in Tracking Time is used as a tracking parameter in all static and transient analyses, whether or not the analysis is truly time-dependent. The advantage of this is that you can use one consistent «counter» or «tracker» in all cases, eliminating the need for analysis-dependent terminology. Moreover, time always increases monotonically, and most things in nature happen over a period of time, however brief the period may be. Obviously, in a transient analysis time represents actual, chronological time in seconds, minutes, or hours. In a static analysis, however, time simply becomes a counter that identifies steps and substeps. By default, the program automatically assigns time = 1.0 at the end of step 1, time = 2.0 at the end of step 2, and so on. Any substeps within a step will be assigned the appropriate, linearly interpolated time value. By assigning your own time values in such analyses, you can establish your own tracking parameter. For example, if a load of 100 units is to be applied incrementally over one step, you can specify time at the end of that step to be 100, so that the load and time values are synchronous.

Steps, Substeps, and Equilibrium Iterations What is a step? A step corresponds to a set of loads for which you want to obtain a solution and review results. In this way every static or transient dynamic analysis has at least one step. However there are several scenarios where you may want to consider using multiple steps within a single analysis, that is, multiple solutions and result sets within a single analysis. A static or transient analysis starts at time = 0 and proceeds until a step end time that you specify. This time span can be further subdivided into multiple steps where each step spans a different time range. As mentioned in the Role of Time in Tracking (p. 667) section, each step spans a ‘time’ even in a static analysis.

When do you need Steps? Steps are required if you want to change the analysis settings for a specific time period. For example in an impact analysis you may want to manually change the allowable minimum and maximum time step sizes during impact. In this case you can introduce a step that spans a time period shortly before and shortly after impact and change the analysis settings for that step. Steps are also useful generally to delineate different portions of an analysis. For example, in a linear static structural analysis you can apply a wind load in the first step, a gravity load in the second step, both loads and a different support condition in the third step, and so on. As another example, a transient analysis of an engine might include load conditions corresponding to gravity, idle speed, maximum power, back to idle speed. The analysis may require repetition of these conditions over various time spans. It is convenient to track these conditions as separate steps within the time history. In addition steps are also required for deleting loads or adding new loads such as specified displacements or to set up a pretension bolt load sequence. Steps are also useful in setting up initial conditions for a transient analysis. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Configuring Analysis Settings

How do you define steps? See the procedure, ”Specifying Analysis Settings for Multiple Steps” located in the Establish Analysis Settings (p. 134) section.

What are substeps and equilibrium iterations? Solving an analysis with nonlinearities requires convergence of an iterative solution procedure. Convergence of this solution procedure requires the load to be applied gradually with solutions carried out at intermediate load values. These intermediate solution points within a step are referred to as substeps. Essentially a substep is an increment of load within a step at which a solution is carried out. The iterations carried out at each substep to arrive at a converged solution are referred to as equilibrium iterations.

Load

Substep Load step

Final load value

1

2 Equilibrium iterations

Substeps

Automatic Time Stepping Auto time stepping, also known as time step optimization, aims to reduce the solution time especially for nonlinear and/or transient dynamic problems by adjusting the amount of load increment. If nonlinearities are present, automatic time stepping gives the added advantage of incrementing the loads appropriately and retreating to the previous converged solution (bisection) if convergence is not obtained. The amount of load increment is based on several criteria including the response frequency of the structure and the degree of nonlinearities in the analysis. The load increment within a step is controlled by the auto time stepping procedure within limits set by you. You have the option to specify the maximum, minimum and initial load increments. The solution will start with the “initial” increment but then the automatic procedure can vary further increments within the range prescribed by the minimum and maximum values. You can specify these limits on load increment by specifying the initial, minimum, and maximum number of substeps that are allowed. Alternatively, since a step always has a time span (start time and end time), you can also equivalently specify the initial, minimum and maximum time step sizes. Although it seems like a good idea to activate automatic time stepping for all analyses, there are some cases where it may not be beneficial (and may even be harmful): • Problems that have only localized dynamic behavior (for example, turbine blade and hub assemblies), where the low-frequency energy content of part of the system may dominate the high-frequency areas.

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Steps and Step Controls for Static and Transient Analyses • Problems that are constantly excited (for example, seismic loading), where the time step tends to change continually as different frequencies are excited. • Kinematics (rigid-body motion) problems, where the rigid-body contribution to the response frequency term may dominate.

Guidelines for Integration Step Size The accuracy of the transient dynamic solution depends on the integration time step: the smaller the time step, the higher the accuracy. A time step that is too large introduces an error that affects the response of the higher modes (and hence the overall response). On the other hand too small a time step size wastes computer resources. An optimum time step size can depend on several factors: 1. Response frequency: The time step should be small enough to resolve the motion (response) of the structure. Since the dynamic response of a structure can be thought of as a combination of modes, the time step should be able to resolve the highest mode that contributes to the response. The solver calculates an aggregate response frequency at every time point. A general rule of thumb it to use approximately twenty points per cycle at the response frequency. That is, if f is the frequency (in cycles/time), the integration time step (ITS) is given by: ITS = 1/(20f ) Smaller ITS values will be required if accurate velocity or acceleration results are needed. The following figure shows the effect of ITS on the period elongation of a single-DOF spring-mass system. Notice that 20 or more points per cycle result in a period elongation of less than 1 percent.

Period Elongation (%)

10 9 8 7 6 5 4 3 2 1 0

recommended 0 10 20 30 40 50 60 70 80 90 100 Number of Time Steps Per Cycle

2. Resolve the applied load-versus-time curve(s). The time step should be small enough to “follow” the loading function. For example, stepped loads require a small ITS at the time of the step change so that Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Configuring Analysis Settings the step change can be closely followed. ITS values as small as 1/180f may be needed to follow stepped loads. ü

ü Inpu Response

t

t

3. Resolve the contact frequency. In problems involving contact (impact), the time step should be small enough to capture the momentum transfer between the two contacting faces. Otherwise, an apparent energy loss will occur and the impact will not be perfectly elastic. The integration time step can be determined from the contact frequency (fc) as: c

c

=

π

where k is the gap stiffness, m is the effective mass acting at the gap, and N is the number of points per cycle. To minimize the energy loss, at least thirty points per cycle of (N = 30) are needed. Larger values of N may be required if velocity or acceleration results are needed. See the description of the Predict for Impact option within the Time Step Controls contact Advanced settings for more information. You can use fewer than thirty points per cycle during impact if the contact period and contact mass are much less than the overall transient time and system mass, because the effect of any energy loss on the total response would be small. 4. Resolve the nonlinearities. For most nonlinear problems, a time step that satisfies the preceding guidelines is sufficient to resolve the nonlinearities. There are a few exceptions, however: if the structure tends to stiffen under the loading (for example, large deflection problems that change from bending to membrane load-carrying behavior), the higher frequency modes that are excited will have to be resolved. After calculating the time step sizes using the above guidelines, you need to use the minimum value for your analysis. However using this minimum time step size throughout a transient analysis can be very inefficient. For example in an impact problem you may need small time step sizes calculated as above only during and for a short duration after the impact. At other parts of the time history you may be able to get accurate results with larger time steps sizes. Use of the Automatic Time Stepping (p. 668) procedure lets the solver decide when to increase or decrease the time step during the solution.

Analysis Settings for Explicit Dynamics Analyses The following sections describe the various analysis settings available for an Explicit Dynamics analysis. In addition to describing each setting, it is noted whether the setting is available for 2D analyses, and whether it is available on restart (applies to 2D and 3D analyses). Explicit Dynamics Step Controls 670

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Analysis Settings for Explicit Dynamics Analyses Explicit Dynamics Solver Controls Explicit Dynamics Euler Domain Controls Explicit Dynamics Damping Controls Explicit Dynamics Erosion Controls Explicit Dynamics Output Controls Explicit Dynamics Data Management Settings Recommendations for Analysis Settings in Explicit Dynamics Explicit Dynamics Analysis Settings Notes

Explicit Dynamics Step Controls Field Resume From Cycle

Options

Description

2D

Restart

Allows you to select the cycle (time increment for explicit integration) from which to start the solution upon selecting Solve. A cycle of zero (default setting) indicates the solution will clear any previous progress and start from time zero. A non-zero cycle, on the other hand, allows you to revisit a previous solution and extend it further in time. A solution obtained from a nonzero cycle is considered to have been «resumed» or «restarted».

Yes

Yes

The maximum number of cycles allowed Yes during the analysis. The analysis will stop once the specified value is reached. Enter a large number to have the analysis run to the defined End Time.

Yes

Note that the list will only contain nonzero selections if a solve was previously executed and restart files have been generated. When resuming an analysis, changes to analysis settings will be respected where possible. For example, you may wish to resume an analysis with an extended termination time. Changes to any other features in the model (geometry suppression, connections, loads, and so on) will prevent restarts from taking place. See Resume Capability for Explicit Dynamics Analyses (p. 1136) for more information. This field is not available for Explicit Dynamics (LS-DYNA Export) systems. Maximum Number of Cycles

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Configuring Analysis Settings Field

Options

Description

2D

Restart

End Time

(Required input) The maximum length of time (starting from zero seconds) to be simulated by the explicit analysis. You should enter a reasonable estimate to cover the phenomena of interest.

Yes

Yes

Maximum Energy Error

Energy conservation is a measure of the quality of an explicit dynamics analysis. Large deviations from energy conservation usually imply a less than optimal model definition. This parameter allows you to automatically stop the solution if the deviation from energy conservation becomes unacceptable. Enter a fraction of the total system energy (measured at the Reference Energy Cycle) for which you want the analysis to stop. For example, the default value of 0.1 will cause the analysis to stop if the energy error exceeds 10% of the energy at the reference cycle.

Yes

Yes

The cycle at which you want the solver to Yes calculate the reference energy, against which it will calculate the energy error. Usually this will be the start cycle (cycle = 0). You may need to increase this value if the model has zero energy at cycle = 0 (for example if you have no initial velocity defined).

Yes

For Explicit Dynamics (LS-DYNA Export) systems this field requires a percentage to be entered. Thus the field name changes to Maximum Energy Error (%). Reference Energy Cycle

This field is not available for Explicit Dynamics (LS-DYNA Export) systems. Initial Time Step

Enter an initial time step you want to use, Yes or use the Program Controlled default. If left on Program Controlled, the time step will be automatically set to ½ the computed element stability time step. The Program Controlled setting is recommended.

Yes

For Explicit Dynamics (LS-DYNA Export) systems if this field is left on Program Controlled, the initial time step will be determined by the solver. Minimum Time Step

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Yes

Analysis Settings for Explicit Dynamics Analyses Field

Options

Description

2D

Restart

the analysis will stop. If set to Program Controlled, the value will be chosen as 1/10th the initial time step. This field is not available for Explicit Dynamics (LS-DYNA Export) systems. Maximum Time Step

Enter the maximum time step allowed in the Yes analysis, or use the Program Controlled default. The solver will use the minimum of this value or the computed stability time step during the solve. The Program Controlled setting is recommended.

Yes

Time Step Safety Factor

It is not wise to run at the stability limit, so a safety factor is applied to the computed stability time step. The default value of 0.9 should work for most analyses.

Yes

Yes

The characteristic dimension used to determine the time-step for hex elements will be calculated as the volume of the element divided by the square of the longest element diagonal and then scaled by sqrt(2/3).

Yes

No

Characteristic Dimension

Diagonals (default setting)

This field is not available for Explicit Dynamics (LS-DYNA Export) systems. Opposing Face

The characteristic dimension used to determine the time-step for hex elements will be based on the minimum distance between opposing faces. Select this option to obtain the optimal time step for hex solid elements. Experience to date has shown that this option can significantly improve the efficiency of 3D Lagrange simulations. However, in certain circumstances when cells become highly distorted, instabilities have been observed causing the calculation to terminate with high energy errors. The correct choice of erosion strain can reduce these problems. It is therefore recommended that users only utilize this option if efficiency is critical. This field is not available for Explicit Dynamics (LS-DYNA Export) systems.

Nearest Face

The characteristic dimension used to determine the time-step for hex ele-

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Configuring Analysis Settings Field

Options

Description

2D

Restart

If set to Yes, activates automatic mass scaling and exposes the following options.

Yes

Yes

The CFL time step that you want to achieve in the analysis.

Yes

Yes

Yes

Yes

ments will be based on the minimum distance between neighboring faces. Experience to date has shown that this option can significantly improve the efficiency of 3D Lagrange simulations. However, in certain circumstances when cells become highly distorted, instabilities have been observed causing the calculation to terminate with high energy errors. The correct choice of erosion strain can reduce these problems. It is therefore recommended that users only utilize this option if efficiency is critical. This field is not available for Explicit Dynamics (LS-DYNA Export) systems. Automatic Mass Scaling Minimum CFL Time Step

Caution Mass scaling introduces additional mass into the system to increase the CFL time step. Introducing too much mass can lead to non-physical results.

Note Employ User Defined Results (p. 970) MASS_SCALE (ratio of scaled mass/physical mass) and TIMESTEP to review the effects of automatic mass scaling on the model. Maximum Element Scaling

This value limits the ratio of scaled mass/physical mass that can be applied to each element in the model. This field is not available for Explicit Dynamics (LS-DYNA Export) systems.

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Analysis Settings for Explicit Dynamics Analyses Field

Options

Description

2D

Restart

Maximum Part Scaling

This value limits the ratio of scaled mass/physical mass that can be applied to an individual body. If this value is exceeded, the analysis will stop and an error message is displayed.

Yes

Yes

Allows you to control the frequency at which Yes the mass scaling will be calculated during the solve. The frequency equates to the increment in cycles at which the mass scale factor will be recomputed, based on the current shape of the elements. The default of 0 is recommended and means that the mass scale factor is only calculated once, at the start of the solve.

Yes

This field is not available for Explicit Dynamics (LS-DYNA Export) systems. Maximum Mass Scaling (%)

This value limits the ratio of scaled mass/physical mass that be be applied to the whole model. The ratio is expressed as a percentage. This field is only available for Explicit Dynamics (LS-DYNA Export) systems.

Update Frequency

This field is not available for Explicit Dynamics (LS-DYNA Export) systems.

Explicit Dynamics Solver Controls Field

Options

Solve Units

Description

2D

Restart

All model inputs will be converted to this set of units during the solve. Results from the analysis will be converted back to the user units system in the GUI. For Explicit Dynamics systems, this setting is always mm, mg, ms.

Yes

No

Any line bodies will be represented as beam No elements including a full bending moment calculation.

No

For Explicit Dynamics (LS-DYNA Export) systems this field is termed Unit System and four systems are available for selection: m, kg, s, mm, ton, s, mm, mg, ms, in, lbf, s. Beam Solution Type

Bending

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Configuring Analysis Settings Field

Options

Description

Truss

Any line bodies will be represented as truss elements. No bending moments are calculated.

Beam Time Step Safety Factor

Hex Integration Type

2D

Restart

An additional safety factor you may apply No to the stability time step calculated for beam elements. The default value ensures stability for most cases.

No

Exact

Provides an accurate calculation of element volume, even for warped elements.

No

No

1pt Gauss

Approximates the volume calculation and is less accurate for elements featuring warped faces. This option is more efficient.

Shell Sublayers

The number of integration points through the thickness of an isotropic shell. The default of 3 is suitable for many applications however this number can be increased to achieve better resolution of through thickness plastic deformation and/or flow.

No

No

Shell Shear Correction Factor

The transverse shear in the element formu- No lation is assumed constant over the thickness. This correction factor accounts for the replacement of the true parabolic variation through the thickness in response to a uniform transverse shear stress. Using a value other than the default is not recommended.

No

Shell BWC Warp Correction

The Belytschko-Lin-TSy element formulation No becomes inaccurate if the elements are warped. To overcome this, the element formulation has an optional correction to include warping. Setting this correction to Yes is recommended.

No

Changes in shell thickness are calculated at the nodes of shell elements.

No

No

N/A

N/A

Shell Thickness Update

Nodal

This field is not available for Explicit Dynamics (LS-DYNA Export) systems. Elemental

Changes in shell thickness are calculated at the element integration points. This field is not available for Explicit Dynamics (LS-DYNA Export) systems.

Full Shell Integration

Available only for Explicit Dynamics (LSDYNA Export) systems. Provides a very fast and accurate shell element formulation.

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Analysis Settings for Explicit Dynamics Analyses Field

Options

Description

2D

Tet Integration

Average Nodal Pressure

The tetrahedral element formulation includes No an average nodal pressure integration. This formulation does not exhibit volumetric locking, and can be used for large deformation, and nearly incompressible behavior such as plastic flow or hyperelasticity. This formulation is recommended for the majority of tetrahedral meshes.

Restart No

Constant Pressure Uses the constant pressure integrated tetrahedral formulation. This formulation is more efficient than Average Nodal, however it suffers from volumetric locking under constant bulk deformation. Nodal Strain

When Tet Integration is set to Nodal Strain the Puso Stability Coefficient, field is shown. For NBS models exhibiting zero energy modes, the Puso coefficient can be set to a non-zero value. A value of 0.1 is recommended. See Solver Controls (p. 1794) for more information.

Shell Inertia Update

Recompute

The principal axes of rotary inertia are by default recalculated each cycle.

No

No

Yes

No

This field is not available for Explicit Dynamics (LS-DYNA Export) systems. Rotate

Rotates the axes, rather than recomputing each cycle. This option is more efficient, however it can lead to numerical instabilities due to floating point round-off for long running simulations. This field is not available for Explicit Dynamics (LS-DYNA Export) systems.

Density Update

Program Controlled

The solver decides whether an incremental update is necessary based on the rate and extent of element deformation. This field is not available for Explicit Dynamics (LS-DYNA Export) systems.

Incremental

Forces the solver to always use the incremental update. This field is not available for Explicit Dynamics (LS-DYNA Export) systems.

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677

Configuring Analysis Settings Field

Options

Description

2D

Restart

Total

Forces the solver to always recalculate the density from element-volume and mass.

Yes

Yes

The maximum velocity you want to allow in Yes the analysis. If any model velocity rises above the Maximum Velocity, it will be capped. This can improve the stability/robustness of the analysis in some instances. The default is recommended for most analyses.

Yes

This field is not available for Explicit Dynamics (LS-DYNA Export) systems. Minimum Velocity

The minimum velocity you want to allow in the analysis. If any model velocity drops below this Minimum Velocity, it will be set to zero. The default is recommended for most analyses. This field is not available for Explicit Dynamics (LS-DYNA Export) systems.

Maximum Velocity

This field is not available for Explicit Dynamics (LS-DYNA Export) systems. Radius Cutoff

At the start of your calculation, if a node is Yes within the specified radius of a symmetry plane, it will be placed on the symmetry plane. If a node is outside the specified radius from a symmetry plane at the start of your calculation, it will not be allowed to come closer than this radius to the symmetry plane as your calculation proceeds.

Yes

This field is not available for Explicit Dynamics (LS-DYNA Export) systems. Minimum Strain Rate Cutoff

The minimum strain rate you want to allow Yes in the analysis. If any model strain rate drops below this value, it will be set to zero. The default is recommended for most analyses. For low speed or quasi-static analyses, it may be necessary to decrease this value.

Yes

This field is not available for Explicit Dynamics (LS-DYNA Export) systems.

Explicit Dynamics Euler Domain Controls Field

Options

Description

2D

Restart

Domain Size Definition

Program Controlled

Set Domain Size Definition to automatic

No

No

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Analysis Settings for Explicit Dynamics Analyses Field

Options

Description

2D

Restart

Manual

Set Domain Size Definition to manual Toggles visibility of the annotation of the Euler domain in the graphics window

No

No

All Bodies

Euler domain is sized to include all bodies

No

No

Eulerian Bodies Only

Euler domain is sized to include Euler bodies only

X Scale factor, Y Scale factor, Z Scale Factor

User defined scaling factors for the automat- No ically determined X, Y, and Z sizes

No

Minimum X Coordinate, Minimum Y Coordinate, Minimum Z Coordinate

X, Y, Z coordinates for the Euler domain origin for the Manual option

No

No

X Dimension, Y Dimension, Z Dimension

Euler domain X, Y, Z dimensions for the Manual option

No

No

Total Cells

Set Domain Resolution Definition by specify- No ing the total number of cells in the Euler domain

No

Cell Size

Set Domain Resolution Definition by specifying the size of the cells in the Euler domain

Display Euler Domain Scope

Domain Resolution Definition

Cells per Compon- Set Domain Resolution Definition by specifyent ing the number of cells in each dimension in the Euler domain Total Cells

Total number of cells that the Euler domain should contain if Domain Resolution Definition is Total Number of Cells

No

No

Cell Size

Dimension of the cell in each of the X, Y, and No Z directions if Domain Resolution Definition is Cell Size

No

Number of Cells in X, Number of Cells in Y, Number of Cells in Z

Number of cells required in the X, Y, and Z directions if Domain Resolution Definition is Number of Cells by Component

No

No

No

Lower X Face, Lower Y Face, Lower Z Face, Upper X Face, Upper Y Face, Upper Z Face

Flow Out (Default setting)

Specify the boundary condition of the selec- No ted Euler domain face to be Flow Out

Impedance

Specify the boundary condition of the selected Euler domain face to be Impedance

Rigid

Specify the boundary condition of the selected Euler domain face to be Rigid

Euler Tracking

By Body

Results may be scoped to Eulerian bodies in the same way as for Lagrangian bodies

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No

No

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Configuring Analysis Settings

Explicit Dynamics Damping Controls Field

Options

Description

2D

Restart

Linear Artificial Viscosity

A linear coefficient of artificial viscosity. This Yes coefficient smooths out shock discontinuities over the mesh. Using a value other than the default is not recommended.

Yes

Quadratic Artificial Viscosity

A quadratic coefficient of artificial viscosity. Yes This coefficient damps out post shock discontinuity oscillations. Using a value other than the default is not recommended.

Yes

Linear Viscosity in Expansion

Artificial viscosity is normally applied to materials in compression only. This option allows you to apply the viscosity for materials in compression and expansion.

Yes

Yes

The method of hourglass damping to be used with solid hexahedral elements.

No

Yes

Stiffness Coefficient

The Stiffness Coefficient for Flanagan Belytschko hourglass damping in solid hexahedral elements.

No

Yes

Viscous Coefficient

The viscous coefficient for hourglass damping used in hexahedral solid elements and quadrilateral shell elements.

No

Yes

Static Damping

A static damping constant may be specified Yes which changes the solution from a dynamic solution to a relaxation iteration converging to a state of stress equilibrium. For optimal convergence, the value chosen for the damping constant, R, may be defined by: R = 2*timestep/T where timestep is the expected average value of the timestep and T is longest period of vibration for the system being analyzed.

Yes

This field is not available for Explicit Dynamics (LS-DYNA Export) systems. Hourglass Damping

AUTODYN Standard Flanagan Belytschko

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Analysis Settings for Explicit Dynamics Analyses

Explicit Dynamics Erosion Controls Field On Geometric Strain Limit

Options

Description

2D

Restart

If set to Yes, elements will automatically erode if the geometric strain in the element exceeds the specified limit.

Yes

Yes

The geometric strain limit for erosion. Recom- Yes mended values are in the range from 0.75 to 3.0. The default value is 1.5.

Yes

This field is not available for Explicit Dynamics (LS-DYNA Export) systems. Geometric Strain Limit

This field is not available for Explicit Dynamics (LS-DYNA Export) systems. On Material Failure

If set to Yes, elements will automatically Yes erode if a material failure property is defined in the material used in the elements, and the failure criteria has been reached. Elements with materials including a damage model will also erode if damage reaches a value of 1.0.

Yes

This field is not available for Explicit Dynamics (LS-DYNA Export) systems. On Minimum Element Time Step

If set to Yes, elements will automatically Yes erode if their calculated time step falls below the specified value.

Yes

Minimum Element Time Step

The minimum controlling time step that an Yes element can have. If the element time step drops below the specified value, the element will be eroded.

Yes

This field is not displayed for Explicit Dynamics (LS-DYNA Export) systems when On Minimum Element Time Step is set to No. Retain Inertia of Eroded Material

If all elements that are connected to a node in the mesh erode, the inertia of the resulting free node can be retained if this option is set to Yes. The mass and momentum of the free node is retained and can be involved in subsequent impact events to transfer momentum in the system.

Yes

No

If set to No, all free nodes will be automatically removed from the analysis.

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Configuring Analysis Settings Field

Options

Description

2D

Restart

Description

2D

Restart

During the solve of an explicit dynamics system, results are saved to disk at a frequency defined through this control. The following settings are available.

Yes

Yes

Save results files after a specified increment in the number of cycles. Exposes a Cycles field where you enter the increment in cycles.

Yes

Yes

This field is not displayed for Explicit Dynamics (LS-DYNA Export) systems when On Minimum Element Time Step is set to No.

Explicit Dynamics Output Controls Field

Options

Save Results on

Cycles

This setting is not available for Explicit Dynamics (LS-DYNA Export) systems. Time

Save results file after a specified increment in time. Exposes a Time field where you enter a time increment.

Yes

Yes

Equally Spaced Points

(Default) Save a specified number of result files during the analysis. The frequency is defined by the termination time / number of points. Exposes a Number of Points field where you enter the number of results files required.

Yes

Yes

During the solve of an explicit dynamics system, restart files are saved to disk at a frequency defined through this control. The following settings are available.

Yes

Yes

Cycles

Save restart files after a specified increment in the number of cycles. Exposes a Cycles field where you enter the increment in cycles.

Yes

Yes

Time

Save restart files after a specified increments Yes in time. Exposes a Time field where you enter a time increment.

Yes

Save Restart Files on

This setting is not available for Explicit Dynamics (LS-DYNA Export) systems. Equally Spaced Points

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(Default) Save a specified number of restart files during the analysis. The frequency is defined by the termination time / number of points. Exposes a Number of Points field

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Yes

Yes

Analysis Settings for Explicit Dynamics Analyses Field

Options

Description

2D

Restart

Yes

Yes

(Default) Save results tracker and solution Yes output data after a specified increment in the number of cycles. Exposes a Cycles field where you enter the increment in cycles. The default value is 1.

Yes

where you enter the number of restart files required. Save Result Tracker Data on

Use this control to define the frequency at which result tracker data and solution output is saved to disk. Result tracker data objects are scoped to specific regions in a model. Solution output provides a summary of the state of the solution as the solve proceeds. This is shown when Solution Information is highlighted in the project tree. This setting applies to all the selectable views in the Solution Output drop down list located in the Solution Information Details view. This field is not available for Explicit Dynamics (LS-DYNA Export) systems. Cycles

If a number less than or equal to 10 is entered for Cycles, then the following plots available from the Solution Output drop down will be updated every 10 cycles unless overall progress has increased by 5% since the last data point (in which case, the plots will be updated at a frequency as close to the entered cycle increment as possible). Results trackers are excluded from this limitation. • Time Increment • Energy Conservation • Momentum Summary • Energy Summary The Solver Output view from the Solution Output drop down will be updated at the entered cycle increment.

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Configuring Analysis Settings Field

Options

Description

2D

Restart

Yes

Yes

No

Yes

Cycle zero and the final cycle will always be displayed even if it is not a multiple of the cycles entered. Time

Save result tracker and solution output data after a specified increment in time. Exposes a Time field where you enter a time increment. Although time based, the frequency of Solution Output update is limited to no more than every 10 cycles. If a time equating to 10 cycles or less is chosen, then the following plots available from the Solution Output drop down will be updated every 10 cycles, unless overall progress has increased by 5% since the last data point (in which case, the output will be updated at a frequency as close to the entered time increment as possible). Results trackers are excluded from this limitation. • Time Increment • Energy Conservation • Momentum Summary • Energy Summary The Solver Output view from the Solution Output drop down will be updated every cycle.

Output Contact Forces

Use this control to define the frequency that contact forces are written out to file. • Contact forces information is written to the solution directory into ASCII files named extfcon_*.cfr, where * is the cycle number. • Each file contains forces in the global x, y and z directions for nodes on external faces, where the forces are non-zero. • Contact forces are not written for Line bodies or Eulerian (Virtual) bodies. • Contact forces are only written for 3D analyses.

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Analysis Settings for Explicit Dynamics Analyses Field

Options

Description

2D

Restart

• A separate line pair exists for each node in the following format: Node number Contact Force X

Contact Force Y

Contact Force Z

• These text files may be used by ACT to visualize the contact pressure between bodies. Off

(Default) Disable output of contact forces.

No

Yes

Cycles

Write contact forces to a file after a specified No increment in the number of cycles. Exposes a Cycles field where you enter the increment in cycles.

Yes

Time

Write contact forces to a file after a specified No increment in time. Exposes a Time field where you enter a time increment.

Yes

Equally Spaced Points

Write a specified number of contact force No files during the analysis. The frequency is defined by the termination time/ number of points. Exposes a Number of Points field where you enter the number of contact force files required.

Yes

Explicit Dynamics Data Management Settings Note that these settings cannot be changed from the Details panel. Field

Description

Solver Files Directory

The permanent location for all the files generated during a solve. This is a read-only field provided for information.

Scratch Solver Files Directory

A temporary location for all files generated during a solve. These files are then moved to the Solver Files Directory for completed solves. This is a read-only field provided for information. See Analysis Data Management (p. 664) for more information. This field is not available for Explicit Dynamics (LS-DYNA Export) systems.

Recommendations for Analysis Settings in Explicit Dynamics Explicit Dynamics may be used for a wide range of applications, and the default set of Analysis Settings are not necessarily suited to every application. The Analysis Settings defaults for the Explicit Dynamics system have been selected in order to provide the most robust solution. This is sometimes at the expense of speed of solution. Therefore, a new Analysis Settings Preference section has been added containing the Type setting. This will allow the selection of particular defaults depending on the requirements of the user. The following options are available: Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Configuring Analysis Settings • Program Controlled – This is the default setting and is identical to the analysis settings for older versions of the Explicit Dynamics systems. The priority is for a robust solution. • Low Velocity – Recommended for low deformation/velocity (<100m/s) analyses. • High Velocity – Recommended for high deformation/velocity (>100m/s) analyses. • Efficiency – Settings for minimum runtime. In some cases, this may have an impact on robustness and accuracy. • Quasi-static – Recommended for quasi-static analyses. The exact Analysis Settings values for each of the Analysis Settings Preference Types are shown in the table below. Switching the Type property will update all of the items displayed in the table as indicated. If any of these settings are subsequently changed, then the Type will be indicated as Custom. Program Controlled

Efficiency

Low Velocity

High Velocity

QuasiStatic

Default (Robustness)

Setting for minimum run time (also minimum robustness and accuracy in some cases)

Recommended setting for low deformation/velocity simulations (<100m/s)

Recommended for high deformation/velocity simulations (>100m/s)

Recommended setting for quasistatic simulations

Analysis Settings

Notes

Step Controls Timestep Safety Factor

0.9

1

0.9

0.9

0.9

If solving in the Euler reference frame the maximum timestep safety factor is 0.66667. This will override any values entered by the user.

Mass Scaling

No

Yes

Yes

No

Yes

The user needs to enter a reasonable desired timestep.

Mass Scaling: Minimum CFL timestep

Off

User Must Define

User Must Define

Off

User Must Define

The user needs to enter a sensible desired timestep and ensure the physical response is not significantly altered by the additional mass added.

1000

100

Off

1000

Mass Scaling: Off Maximum Ele-

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Analysis Settings for Explicit Dynamics Analyses Program Controlled

Efficiency

Low Velocity

High Velocity

QuasiStatic

Mass Scaling: Maximum Part Scaling

Off

1000

5

Off

1000

Mass Scaling: Update Frequency

Off

0

0

Off

0

Characteristic Dimension

Diagonals

Opposing Faces

Opposing Faces

Diagonals

Opposing Faces

Beam Time Step Safety Factor

0.5

1

0.1

0.1

0.1

Hex Integration Type

Exact

1pt Gauss

1pt Gauss

Exact

1pt Gauss

Shell Sublayers

3

2

3

3

3

Shell Inertia Update

Recompute

Rotate

Recompute

Recompute

Recompute

Rotate option is most efficient but can lead to unstable results. Check results carefully.

Tet Integration

ANP

SCP

NBS

ANP

NBS

SCP tet is very efficient but suffers from shear and volume locking. Check results carefully if using this option.

Minimum Strain Rate Cutoff

1e-10

1e-10

0.0

1e-10

0.0

AUTODYN standard

AUTODYN standard

Flanagan Belytschko

AUTODYN standard

Flanagan Belytschko

ment Scaling Factor (%)

Note that for low deformation problems, setting an update frequency of approximately 250 may also help maintain a higher timestep

Solver Controls Increasing the safety factor can lead to unstable results. Check results carefully.

Damping Controls Hourglass Damping

Autodyn standard is not rigid body rotation invariant. Must use Flanagan Belytschko if large rotations are involved.

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Configuring Analysis Settings Program Controlled

Efficiency

Low Velocity

High Velocity

QuasiStatic

0

0

0

0

User Must Define

For quasi-static analyses, it is recommended that static damping is used, but the value used depends on the configuration of the model. See Explicit Dynamics Damping Controls (p. 680) for more details on selecting an appropriate value.

On Geometric Strain Limit

Yes

No

No

Yes

No

If you expect large deformations and mesh distortions during the simulation, a geometric strain limit of 1.0 to 1.5 will be required for the minimum run time case.

Geometric Strain Limit

1.5

0.75

Unchanged

1.5

Unchanged

Save Results on: Equally Spaced Points

20

20

50

50

10

Save Result Tracker Data: Cycles

1

10

10

1

10

Save Solution Output: Cycles

100

1000

100

100

100

Body Self Contact

Yes

No

No

Yes

No

Element Self Contact

Yes

No

No

Yes

No

Static Damping

Erosion Controls

Output Controls

Body Interactions: Details options

When using the Explicit Dynamics analysis system, the Body Self Contact and Element Self Contact settings in the Body Interactions object Details panel should be set to Program Controlled in order for

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Analysis Settings for Explicit Dynamics Analyses the Analysis Settings Preference Type to have an effect on the Body Interactions objects. If the Program Controlled setting is used, the values of the Body Interactions settings will be as shown in the table.

Note Keep in mind the following guidelines for setting up other areas of your analysis: • Material Properties – Use Simplest Material definition possible – Use Linear Elastic properties unless you need to model non-linearities • Bonds – Only use breakable bonds if you really need to • Meshing Mesh quality is a critical aspect for model performance and accuracy – Use Hex Meshes whenever possible – Use the patch independent tetrahedral mesh method to ensure uniform element size and timestep optimization – Avoid small elements unless you need them

Explicit Dynamics Analysis Settings Notes If any bodies are defined as Eulerian (Virtual), when Analysis Settings is selected in the outline view the Euler domain bounding box is displayed in the graphics window, as shown below.

The Euler domain resolution is indicated by black node markers along each edge line of the Euler domain. The visibility of this can be controlled by the Display Euler Domain option in the Analysis Settings.

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Setting Up Boundary Conditions Boundary conditions are often called «loads» or «supports». They constrain or act upon your model by exerting forces or rotations or by fixing the model it such a way that it cannot deform. Boundary conditions are typically applied to 2D or 3D simulations but exceptions do exist. Any exceptions are discussed in detail on the Help page for the particular boundary condition. The boundary conditions you apply depend on the type of analysis you are performing. In addition, the geometry (body, face, edge, or vertex) or finite element selection to which a boundary condition is applied, also varies per analysis type. Once applied, and as applicable to the boundary condition type, the loading characteristics must be considered. This includes, whether the boundary condition is defined as a constant, by using tabular entries (time history or spatially varying), or as a function (time history or spatially varying). The following topics describe the steps involved in applying and using boundary conditions in the application. Boundary Condition Scoping Method Types of Boundary Conditions Spatial Varying Loads and Displacements Defining Boundary Condition Magnitude

Boundary Condition Scoping Method Almost every boundary condition available in the application has a Details group, Scope, that includes the property Scoping Method; a Pressure load is illustrated below. Scope refers to the geometry over which a boundary condition is applied. You can select geometry or geometries of your model using geometry selection tools (Geometry Selection) or through the use of the Named Selection feature. You can “scope” boundary conditions to one or more bodies, faces, edges, or vertices. In some cases you can scope boundary conditions directly to the nodes of the finite element mesh.

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Setting Up Boundary Conditions For example, if you apply a force of 1000N in the X-direction to a vertex, the load is «scoped» to that vertex.

Scoping Method Techniques The application provides several common methods for scoping boundary conditions. Regardless of the method you choose, you need to select geometry entities of the model and scope those entities with a boundary condition. The order of these selections can vary. You can first select a boundary condition and then specify a geometry: 1. Highlight the Environment object. 2. Click the desired drop-down menu from the context toolbar and select your boundary condition type. 3. Select the desired geometry or geometries (by pressing and holding [CTRL]) on your model and then clicking the Apply button. Perform any additional required entries. In the example shown here, a Pressure was applied to a face. The Magnitude entry is undefined.

Or you can first select geometries and then apply boundary conditions: 1. Highlight the Environment object 2. Pick your geometry. 3. Apply your boundary condition by: a. Making a selection from the Environment context toolbar.

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Boundary Condition Scoping Method

Or… b. Selecting the Environment object, right-clicking the mouse, selecting Insert, and then select your desired boundary condition.

Or… c. Right–clicking the mouse while in the Geometry window, selecting Insert, and then select your desired boundary condition.

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Setting Up Boundary Conditions

Again, additional entries are typically required. For example, you may need to enter a Magnitude for the boundary condition, specify a Coordinate System, and/or define a Direction.

Types of Boundary Conditions The Environment Context Toolbar groups most of the application’s boundary conditions within the menus listed below. • Inertial • Loads • Supports • Conditions • Direct FE See the following sections for information about how to import loading conditions as well as how to apply and scope abstract loading through the use of remote conditions. • Remote Boundary Conditions • Imported Boundary Conditions

Inertial Type Boundary Conditions The boundary conditions contained under the Inertial heading are listed below. • Acceleration • Standard Earth Gravity • Rotational Velocity

Acceleration The global Acceleration boundary condition defines a linear acceleration of a structure in each of the global Cartesian axis directions.

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Types of Boundary Conditions If desired, acceleration can be used to simulate gravity (by using inertial effects) by accelerating a structure in the direction opposite of gravity (the natural phenomenon of ). That is, accelerating a structure vertically upwards (+Y) at 9.80665 m/s2 (in metric units), applies a force on the structure in the opposite direction (-Y) inducing gravity (pushing the structure back towards earth). Units are length/time2. Alternatively, you can use the Standard Earth Gravity load to produce the effect of gravity. Gravity and Acceleration are essentially the same type of load except they have opposite sign conventions and gravity has a fixed magnitude. For applied gravity, a body tends to move in the direction of gravity and for applied acceleration, a body tends to move in the direction opposite of the acceleration.

Analysis Types Acceleration is available for the following analysis types: • Explicit Dynamics • Harmonic Response • Rigid Dynamics • Static Structural • Transient Structural

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types Acceleration applies a uniform load over all bodies. • 3D Simulation – Supported. • 2D Simulation – Supported. Geometry Types and Topology: By virtue of Acceleration’s physical characteristics, this boundary condition is always applied to all bodies of a model. Loading Types: The boundary condition’s loading is defined using one of the following options: • Vector – Supported. While loads are associative with geometry changes, load directions are not. This applies to any load that requires a vector input, such as acceleration. The vector load definition displays in the Annotation legend with the label Components. The Magnitude and Direction entries, in any combination or sequence, define these displayed values. These are the values sent to the solver. • Components – Supported. Loading Data Definition: Enter loading data using one of the following options. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions • Constant • Tabular (Time Varying) • Tabular (Frequency Varying) — Supported for Harmonic Response Analysis only. By default, at least two frequency entries are required when defining a frequency dependent tabular load. • Function (Time Varying)

Boundary Condition Application To apply Acceleration: 1. On the Environment context toolbar: click Inertial>Acceleration. Or, right–click the Environment object in the tree or Geometry window and select Insert>Acceleration. 2. Select the method used to define the Acceleration: Vector or Components. 3. Define the loading inputs: Magnitude, Coordinate System, and/or Direction of the Acceleration based on the above selections.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Geometry — Read-only field indicating All Bodies.

Definition

Define By — Options include: • Vector — Requires the specification of the following inputs: – Magnitude – Direction • Coordinate System- Drop-down list of available coordinate systems. Global Coordinate System is the default. When using cyclic symmetry, the referenced coordinate system must match coordinate system used in the Cyclic Region. For a 2D axisymmetric model the referenced coordinate system must be the Global Coordinate System. The referenced coordinate system must be Cartesian. Components — Requires the specification of the following inputs: – X Component – Y Component – Z Component Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

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Types of Boundary Conditions

MAPDL References and Notes The following MAPDL commands and considerations are applicable for this boundary condition. • Acceleration is applied using the ACEL command. • Magnitude (constant, tabular, and function) is always represented as a table in the input file.

Note Should both an Acceleration and a Standard Earth Gravity boundary condition be specified, a composite vector addition of the two is delivered to the solver.

Acceleration Example The following illustrations compare how Acceleration and Gravity can be used to specify a gravitational load with the same result.

Global Acceleration load applied in the +Y direction to simulate gravity.

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Setting Up Boundary Conditions Resulting deformation.

Standard Earth Gravity Example

Standard Earth Gravity applied.

Resulting deformation.

Standard Earth Gravity This boundary condition simulates gravitational effects on a body in the form of an external force. Gravity is a specific example of acceleration with an opposite sign convention and a fixed magnitude. Gravity loads cause a body to move in the direction of gravity. Acceleration loads cause a body to move in the direction opposite of the acceleration. Refer to the example shown under Acceleration (p. 694) for details.

Analysis Types Standard Earth Gravity is available for the following analysis types:

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Types of Boundary Conditions • Explicit Dynamics • Rigid Dynamics • Static Structural • Transient Structural

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation – Supported. • 2D Simulation – Supported. Geometry Types and Topology: By virtue of Standard Earth Gravity’s physical characteristics, this boundary condition is always applied to all bodies of a model. Loading Types: This boundary condition’s loading is defined using a Coordinate System as the loading quantity. Loading Data Definition: Standard Earth Gravity is constant, only the direction may be modified.

Boundary Condition Application To apply Standard Earth Gravity: 1. On the Environment context toolbar: click Inertial>Standard Earth Gravity. Or, right–click the Environment object in the tree or the Geometry window and select Insert>Standard Earth Gravity. 2. Define the Coordinate System and/or Direction of the Standard Earth Gravity.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Geometry — Read-only field indicating All Bodies.

Definition

Coordinate System — Drop-down list of available coordinate systems. Global Coordinate System is the default. When using cyclic symmetry the referenced coordinate system must be the same coordinate system specified on the Cyclic Region. For a 2D axisymmetric model the referenced coordinate system must be the Global Coordinate System. The referenced coordinate system must be Cartesian. X Component — Read-only field with values for components based upon the Direction specification.

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Setting Up Boundary Conditions Category

Fields/Options/Description Y Component — Read-only field with values for components based upon the Direction specification. Z Component — Read-only field with values for components based upon the Direction specification. Suppressed — Include (No — default) or exclude (Yes) the boundary condition. Direction — Define the vector in terms of any of the following directions: +x, -x, +y, -y, +z, -z.

MAPDL References and Notes Standard Earth Gravity is applied using the ACEL command.

Note Should both an Acceleration and a Standard Earth Gravity boundary condition be specified, a composite vector addition of the two is delivered to the solver.

Rotational Velocity Rotational velocity accounts for the structural effects of a part spinning at a constant rate.

Analysis Types Rotational Velocity is available for the following analysis types: • Modal Analysis • Static Structural • Transient Structural

Note • For a Transient Structural analysis that is linked to a Modal Analysis, Rotational Velocity is an invalid boundary condition in the Transient Structural analysis. • For a Modal Analysis, Rotational Velocity is valid only when the following Analysis Settings properties are specified: – Damped is set to Yes in the Solver Controls group. – Coriolis Effect property is set to On in the Rotordynamics Controls group.

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Types of Boundary Conditions

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation – Supported. A rotational velocity is applied along a user defined axis to one or more bodies. • 2D Simulation – Supported. For 2D axisymmetric simulations, a Rotational Velocity load can only be applied about the y-axis. Geometry Types: Geometry types supported for the Rotational Velocity boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported. Topology: The following topology selection options are supported for Rotational Velocity. • Body — Supported. One rotational velocity load can be applied to one or more bodies. However, multiple rotational velocity loads cannot be applied to the same body. Attempting to apply more than one rotational velocity load to the same body will invalidate the loads. See the CGOMGA (Structural and Transient) and CMOMEGA (Modal Analysis) commands in Mechanical APDL Command Reference. • Face — Not Supported. • Edge — Not Supported. • Vertex — Not Supported. • Nodes — Not Supported. Loading Types: The boundary condition’s loading is defined using one of the following options. • Vector – Supported. While loads are associative with geometry changes, load directions are not. The vector load definition displays in the Annotation legend with the label Components. The Magnitude and Direction entries, in any combination or sequence, define these displayed values. These are the values sent to the solver. • Components – Supported. Loading Data Definition: Enter loading data using one of the following options. • Constant • Tabular (Time Varying) • Function (Time Varying)

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Boundary Condition Application To apply rotational velocity to all bodies, in the Details view, accept the default Geometry setting of All Bodies. To apply rotational velocity to selected bodies, in the Details view, set Scoping Method to either Geometry Selection or Named Selection, then either select the bodies in the Geometry window (hold down the Ctrl key to multiple select) or select from the list of the Named Selections available in the Details view. To apply additional rotational velocity loads, you must have applied the original load to selected bodies, per above, not to All Bodies. To apply a Rotational Velocity: 1. On the Environment context toolbar: click Inertial>Rotational Velocity. Or, right-click the Environment tree object or the Geometry window and select Insert>Rotational Velocity. 2. Select a Scoping Method. 3. Select the method used to define the Rotational Velocity: Vector (default) or Components. 4. Define the Magnitude, Component values, Coordinate System, and/or Direction of the Rotational Velocity based on the above selections.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Define By (In a cyclic symmetry analysis, the Rotational Velocity must be defined by components.) — Options include: • Vector — A magnitude and directional axis (based on selected geometry). Requires the specification of the following inputs:

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Types of Boundary Conditions Category

Fields/Options/Description – Magnitude – Axis • Components — Requires the specification of the following inputs: – Coordinate System — Drop-down list of available coordinate systems. Global Coordinate System is the default. When using cyclic symmetry, the referenced coordinate system must match coordinate system used in the Cyclic Region. The referenced coordinate system must be Cartesian. – X Component — Defines magnitude in the X direction. – Y Component — Defines magnitude in the Y direction. – Z Component — Defines magnitude in the Z direction. – X Coordinate – Y Coordinate – Z Coordinate

Note In a Modal analysis: • With multiple solve points (Campbell Diagram turned On), the magnitude or the resultant of the components must be in ascending order. • When specified by Components, only the Global Coordinate System is available (the option is read-only).

Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

MAPDL References and Notes The following MAPDL commands and considerations are applicable for this boundary condition. • Rotational Velocity is applied using the CGOMGA command for a Static or Transient analysis • Rotational Velocity is applied using the CMOMEGA command for a Modal analysis.

Load Type Boundary Conditions The boundary conditions contained under the Loads heading are listed below. They are separated into groups based on their physics and the applicable analysis types.

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Setting Up Boundary Conditions

Structural Loads Pressure Pipe Pressure Pipe Temperature Hydrostatic Pressure Force Remote Force Bearing Load Bolt Pretension Moment Generalized Plain Strain Line Pressure PSD Base Excitation RS Base Excitation Joint Load Thermal Condition

Thermal Loads Temperature Convection Radiation Heat Flow Heat Flux Internal Heat Generation

Electric Loads Voltage Current Thermal Condition

Magnetostatic Loads Electromagnetic Boundary Conditions and Excitations Magnetic Flux Boundary Conditions Conductor

Interaction Loads The following loads involve interactions between the Mechanical application and other products. Motion Load Fluid Solid Interface

Explosive Initiation Detonation Point

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Types of Boundary Conditions

Pressure A pressure load applies a constant pressure or a varying pressure in a single direction (x, y, or z) to one or more flat or curved faces. A positive value for pressure acts into the face, compressing the solid body.

Analysis Types Pressure is available for the following analysis types: • Harmonic Response • Explicit Dynamics • Static Structural • Transient Structural

Note Eigen Response Analyses (Linear Buckling Analysis and Modal Analysis) take into account any pressure load stiffness contribution applied in the linked Static Structural analysis.

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Types Supported • 3D Simulation – Supported. For 3D simulations, a pressure load applies a pressure to one or more faces. • 2D Simulation – Supported. For 2D simulations, a pressure load applies a pressure to one or more edges. Geometry Types: Geometry types supported for the Pressure boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Not Supported. Topology: The following topology selection options are supported for Pressure. • Body — Not Supported. • Face — Supported — 3D. If you select multiple faces when defining the pressure, the same pressure value gets applied to all selected faces. If a constant pressurized face enlarges due to a change in CAD parameters, the total load applied to the face increases, but the pressure (force per unit area) value remains constant. • Edge — Supported — 2D. If you select multiple edges when defining the pressure, the same pressure value gets applied to all selected edges. • Vertex — Not Supported. • Nodes — Not Supported. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions Loading Types: The boundary condition’s loading is defined using one of the following options. • Normal To – Supported. – During a structural analysis, you can also create a spatially varying load using this vector type option. A spatially varying load allows you to define the pressure in tabular form or as a function. – 3D Faces or 2D Edges automatically update their direction at each substep and «follow» the changing normal for large deflection analysis. – Applying a pressure load normal to faces (3D) or edges (2D) could result in a pressure load stiffness contribution that plays a significant role in a pre-stress analysis. This additional effect is computed during a buckling analysis using the pressure value from a Static Structural Analysis from the time at which the restart point occurs. • Vector – Supported. While loads are associative with geometry changes, load directions are not. The vector load definition displays in the Annotation legend with the label Components. The Magnitude and Direction entries, in any combination or sequence, define these displayed values. These are the values sent to the solver. • Components – Supported. Loading Data Definition: Enter loading data using one of the following options. • Constant – Supported. • Tabular (Time Varying) – Supported. • Tabular (Frequency Varying) — Supported for Harmonic Response Analysis only. By default, at least two frequency entries are required when defining a frequency dependent tabular load. • Tabular (Spatially Varying) – Supported. • Function (Time Varying) – Supported. • Function (Spatially Varying) – Supported.

Note Harmonic Response Analysis Only: Spatially varying Tabular and Function data is supported for the Normal To loading type only.

Boundary Condition Application To apply a Pressure: 1. On the Environment context toolbar: click Loads>Pressure. Or, right-click the Environment tree object or the Geometry window and select Insert>Pressure. 2. Define the Scoping Method. 3. Select the method used to define the Pressure: Normal To, Components, or Vector. 706

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Types of Boundary Conditions 4. Define the Magnitude, Coordinate System, and/or Direction of the Pressure based on the above selections. 5. For Harmonic analyses, specify a Phase Angle as needed.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that describes the object — Pressure. Define By — Options include: • Normal To — Requires a Magnitude entry. • Vector — A magnitude and direction (based on selected geometry). Requires the specification of the following inputs: – Magnitude – Direction • Components — Option to define the loading type as Components (in the world coordinate system or local coordinate system, if applied). Requires the specification of at least one of the following inputs: – Coordinate System — Drop-down list of available coordinate systems. Global Coordinate System is the default. – X Component — Defines magnitude in the X direction. – Y Component — Defines magnitude in the Y direction. – Z Component — Defines magnitude in the Z direction. Phase Angle (Harmonic Analysis only) Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Fields/Options/Description Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

MAPDL References and Notes The following MAPDL commands, element types, and considerations are applicable for this boundary condition. • The pressure is applied as a surface load on elements with the SFE command. • During a Structural Analysis, Pressure is applied using the SURF154 (3D) and SURF153 (2D) element types. • Magnitude (constant, tabular, and function) is always represented as a table in the input file.

Pipe Pressure Used in any structural analysis, Pipe Pressure is useful for pipe stress analysis and pipe design. Pipe Pressure is applied only to pipes in the form of line bodies.

Analysis Types Pipe Pressure is available for the following analysis types: • Harmonic Response • Explicit Dynamics • Static Structural • Transient Structural

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation – Supported. For 3D structural analyses, a pipe pressure load applies a constant, tabular, or functional variation of pressure to one or more line bodies which are set to be pipes. • 2D Simulation – Not Supported. Geometry Types: Geometry types supported for the Pipe Pressure boundary condition include: • Solid — Not Supported. • Surface/Shell — Not Supported. • Wire Body/Line Body/Beam — Line Bodies Only. Topology: The following topology selection options are supported for Pipe Pressure. • Body — Not Supported. 708

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Types of Boundary Conditions • Face — Not Supported. • Edge — Supported. • Vertex — Not Supported. • Nodes — Not Supported. Loading Types: The loading type, by default, is program controlled. Internal and external pressures are input on an average basis. By default, when the pipe is subjected to internal and external pressures, the end-cap pressure effect of the pipe is included. This implies that the end caps are always in equilibrium, that is, no net forces are produced. Loading Data Definition: Enter loading data using one of the following options. • Constant • Tabular (Time Varying) • Tabular (Spatially Varying) • Function (Time Varying) • Function (Spatially Varying)

Boundary Condition Application To apply a Pipe Pressure: 1. On the Environment context toolbar: click Loads>Pipe Pressure. Or, right-click the Environment tree object or the Geometry window and select Insert>Pipe Pressure. 2. Define the Scoping Method. Pipe pressure can only be scoped to line bodies which are set to be pipes. 3. Define Magnitude as a constant, tabular, or functional input. 4. For Harmonic analyses, specify a Phase Angle as needed. 5. Select Loading to be Internal or External according to your problem.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions Category

Fields/Options/Description • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that displays boundary condition type — Pipe Pressure. Magnitude — Input field to define the magnitude of the Pipe Pressure. This value can be defined as a Constant or in Tabular form, as well as Imported. Phase Angle (Harmonic Analysis only) Suppressed — Include (No — default) or exclude (Yes) the boundary condition. Loading — Specify whether the loading is Internal or External.

MAPDL References and Notes The following MAPDL element types are applicable for this boundary condition. Both elements are based on Timoshenko beam theory which includes shear-deformation effects. • PIPE288 — 3D two-node pipe • PIPE289 — 3D three-node pipe. • ELBOW290 — special 3D three-node pipe used for modeling curved pipes. This element is also used when Pipe Idealization is scoped to a line body modeled as pipe and meshed with higher order elements. PIPE289 is converted ELBOW290. Displaying Contours and Displaced Shapes on Line Bodies: The contour results line bodies are expanded to be viewed on the cross section shape, but only one actual result exists at any given node and as a result no contour variations across a beam section occur. Therefore, for MAPDL plot comparison, full graphics inside /POST1 should be used when comparing numerical values.

Pipe Temperature For 3D structural analyses, a pipe temperature load applies a constant, tabular, or functional variation of temperature to one or more line bodies which are set to be pipes. You can select it to be internal pipe temperature or external pipe temperature from the Details view.

Analysis Types Pipe Temperature is available for the following analysis types: • Static Structural • Transient Structural

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. 710

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Types of Boundary Conditions Dimensional Types • 3D Simulation – Supported. • 2D Simulation – Not Supported. Geometry Types: Geometry types supported for the Pipe Temperature boundary condition include: • Solid — Not Supported. • Surface/Shell — Not Supported. • Wire Body/Line Body/Beam — Line Bodies Only. Topology: The following topology selection options are supported for Pipe Temperature. • Body — Not Supported. • Face — Not Supported. • Edge — Supported. • Vertex — Not Supported. • Nodes — Not Supported. Loading Types: The loading type is, by default, program controlled. Internal and external temperatures are input on an average basis. Loading Data Definition: Enter loading data using one of the following options. • Constant. • Tabular (Time Varying). • Tabular (Spatially Varying). • Function (Time Varying). • Function (Spatially Varying).

Boundary Condition Application To apply a Pipe Temperature: 1. On the Environment context toolbar: click Loads>Pipe Temperature. Or, right-click the Environment tree object or the Geometry window and select Insert>Pipe Temperature. 2. Define the Scoping Method. Pipe Temperature can only be scoped to line bodies that are set to be pipes. 3. Define Magnitude as a constant, tabular, or functional input. 4. Select Loading to be Internal or External according to your problem.

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Setting Up Boundary Conditions

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that displays boundary condition type — Pipe Temperature. Magnitude — Input field to define the magnitude of the Pipe Pressure. Suppressed — Include (No — default) or exclude (Yes) the boundary condition. Loading — Specify whether the loading is Internal or External.

MAPDL References and Notes The Mechanical APDL Solver is the only solver available for this boundary condition.

Hydrostatic Pressure A hydrostatic pressure load simulates pressure that occurs due to fluid weight.

Analysis Types Hydrostatic Pressure is available for the following analysis types: • Explicit Dynamics • Static Structural • Transient Structural

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Types of Boundary Conditions

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation – Supported. • 2D Simulation – Supported. Geometry Types: Geometry types supported for the Hydrostatic Pressure boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Not Supported. Topology: The following topology selection options are supported for Hydrostatic Pressure. • Body — Not Supported. • Face — Supported (3D). • Edge — Supported (2D). • Vertex — Not Supported. • Nodes — Not Supported. Loading Types: The boundary condition’s loading is defined using one of the following options. • Vector – Supported. The vector load definition displays in the Annotation legend with the label Components. The Magnitude and Direction entries, in any combination or sequence, define these displayed values. These are the values sent to the solver. • Components – Supported. Loading Data Definition: Hydrostatic Pressure is defined as a constant.

Note During a multiple step analysis, tabular data is visible for this boundary condition. This information is read-only but you can use the context menu (right-click) features of the Tabular Data display to activate or deactivate the loading per step.

Boundary Condition Application To apply a Hydrostatic Pressure: 1. On the Environment context toolbar: click Loads>Hydrostatic Pressure. Or, right-click the Environment tree object or the Geometry window and select Insert>Hydrostatic Pressure. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions 2. Define the Scoping Method. Hydrostatic Pressure can only be scoped to faces. 3. Select all of the faces that will potentially enclose the fluid. Or… If you are working with a surface body, specify the Shell Face, defined as the side of the shell (Top or Bottom) on which to apply the hydrostatic pressure load. 4. Specify the magnitude and direction of the Hydrostatic Acceleration. This is typically the acceleration due to gravity, but can be other acceleration values depending on the modeling scenario. For example, if you were modeling rocket fuel in a rocket’s fuel tank, the fuel might be undergoing a combination of acceleration due to gravity and acceleration due to the rocket accelerating while flying. 5. Enter the Fluid Density. 6. Specify the Free Surface Location, defined as the location of the top of the fluid in the container. You can specify this location by using coordinate systems, by entering coordinate values, or by clicking a location on the model. 7. Mesh the model, then highlight the Hydrostatic Pressure load object to display the pressure contours. The following example shows the simulation of a hydrostatic pressure load on the wall of an aquarium. Here the wall is modeled as a single surface body. The load is scoped to the bottom side of the face. A fixed support is applied to the bottom edge. Acceleration due to gravity is used and the fluid density is entered as 1000 kg/m3. Coordinates representing the top of the fluid are also entered. The load plot shown here illustrates the hydrostatic pressure gradient.

Details View Properties The selections available in the Details view are described below.

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Types of Boundary Conditions Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections. • Shell Face – Top – Bottom

Definition

Type — Read-only field that displays boundary condition type — Hydrostatic Pressure. Coordinate System — Drop-down list of available coordinate systems. Global Coordinate System is the default. Suppressed — Include (No — default) or exclude (Yes) the boundary condition. Fluid Density — Input field for fluid density value.

Hydrostatic Acceleration

Define By — Options include: • Vector — A magnitude and direction (based on selected geometry). Requires the specification of the following inputs: – Magnitude – Direction • Components – X Component – Y Component – Z Component

Free Surface Location

X Coordinate

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Setting Up Boundary Conditions Category

Fields/Options/Description Y Coordinate Z Coordinate Location — Specify Free Surface Location using geometry picking tools. Valid topologies include: face, edge, vertex.

MAPDL References and Notes The following MAPDL commands, element types, and considerations are applicable for this boundary condition. • Hydrostatic pressure is applied as a surface load on elements with the SF command. • Hydrostatic pressure is applied using the SURF154 (3D) and SURF153 (2D) element types. • Hydrostatic pressure is represented as a table in the input file.

Force Force is specified based on the following topologies: • Face — Distributes a force vector across one or more flat or curved faces, resulting in uniform traction across the face. • Edge — Distributes a force vector along one or more straight or curved edges, resulting in uniform line load along the edge. • Vertex — Applies a force vector to one or more vertices.

Analysis Types Force is available for the following analysis types: • Explicit Dynamics • Harmonic Response • Static Structural • Transient Structural

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation – Supported. • 2D Simulation – Supported. Force loads are not supported for 2D axisymmetric Explicit Dynamics analyses. Geometry Types: Geometry types supported for the Force boundary condition include: 716

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Types of Boundary Conditions • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported Topology: The following topology selection options are supported for Force. • Body — Not Supported. • Face — Supported. – The force is applied by converting it to a pressure, based on the total area of all the selected faces. – If a face enlarges due to a change in CAD parameters, the total load magnitude applied to the face remains constant. – If you try to apply a force to a multiple face selections that span multiple parts, the face selections are ignored. The geometry property for the load object displays ‘No Selection’ if the load was just created, or it maintains its previous geometry selection if there was one. • Edge — Supported. – If you select multiple edges when defining the force, the magnitude of the force is distributed evenly across all selected edges. – If an edge enlarges due to a change in CAD parameters, the total load magnitude applied to the edge remains constant. – If you try to apply a force to a multiple edges that span multiple parts, the edge selections are ignored. The geometry property for the load object displays ‘No Selection’ if the load was just created, or it maintains its previous geometry selection if there was one. • Vertex — Supported. – If you select multiple vertices when defining the force, the magnitude of the force is distributed evenly across all selected vertices. – A force applied to a vertex is not realistic and leads to singular stresses (that is, stresses that approach infinity near the loaded vertex). You should disregard stress and elastic strain values in the vicinity of the loaded vertex. – If you try to apply a force to a multiple vertex selection that spans multiple parts, the vertex selection is ignored. The geometry property for the load object displays ‘No Selection’ if the load was just created, or it maintains its previous geometry selection if there was one. • Nodes — Supported. Loading Types: The boundary condition’s loading is defined using one of the following options. • Vector – Supported. While loads are associative with geometry changes, load directions are not. This applies to any load that requires a vector input, such as a force. The vector load definition displays in the Annotation legend with the label Components. The Magnitude and Direction entries, in any combination or sequence, define these displayed values. These are the values sent to the solver. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions • Components – Supported. Loading Data Definition: Enter loading data using one of the following options. • Constant – Supported. • Tabular (Time Varying) — Not supported for Harmonic Response Analysis. • Tabular (Frequency Varying) — Supported for Harmonic Response Analysis only. By default, at least two frequency entries are required when defining a frequency dependent tabular load. • Tabular (Spatially Varying) — Not Supported. • Function (Time Varying) — Not supported for Explicit Dynamics Analysis and Harmonic Response Analysis. • Function (Spatially Varying) — Not Supported.

Boundary Condition Application To apply a Force: 1. On the Environment context toolbar: click Loads>Force. Or, right-click the Environment tree object or the Geometry window and select Insert>Force. 2. Define the Scoping Method. 3. Select the method used to define the force: Vector (default) or Components. 4. Define the Magnitude, Coordinate System directional loading, and/or Direction of the load based on the above selections. 5. For Harmonic analyses, specify a Phase Angle as needed.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection.

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Types of Boundary Conditions Category

Fields/Options/Description – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that describes the object — Force. Define By — Options include: • Vector — A magnitude and direction (based on selected geometry). Requires the specification of the following inputs: – Magnitude – Direction • Components — Option to define the loading type as Components (in the world coordinate system or local coordinate system, if applied). Requires the specification of at least one of the following inputs: – Coordinate System — Drop-down list of available coordinate systems. Global Coordinate System is the default. – X Component — Defines magnitude in the X direction. – Y Component — Defines magnitude in the Y direction. – Z Component — Defines magnitude in the Z direction. Phase Angle (Harmonic Analysis only) Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

MAPDL References and Notes The following MAPDL commands, element types, and considerations are applicable for this boundary condition. • Force is applied using the SFE,,PRES command. • Based on the selected topology, element types include: – SURF154 — 3D structural analyses for face selection. – SURF156 — 3D structural analyses for edge selection. – SURF153 — 2D structural analyses for edge selection. – FOLLW201 — 2D and 3D for vertex selection.

Remote Force A Remote Force is equivalent to a regular force load on a face or a force load on an edge, plus some moment. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions A Remote Force can be used as an alternative to building a rigid part and applying a force load to it. The advantage of using a remote force load is that you can directly specify the location in space from which the force originates.

A Remote Force is classified as a remote boundary condition. Refer to the Remote Boundary Conditions (p. 833) section for a listing of all remote boundary conditions and their characteristics. A Remote Force can be applied to a face, edge, or vertex of a 3D model, or to an edge or vertex of a 2D model.

Analysis Types Remote Force is available for the following analysis types: • Harmonic Response • Rigid Dynamics • Static Structural • Transient Structural

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation – Supported. • 2D Simulation – Supported. Geometry Types: Geometry types supported for the Remote Force boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported. 720

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Types of Boundary Conditions Topology: The following topology selection options are supported for Remote Force. • Body — Not Supported. • Face — Supported 3D Only. • Edge — Supported. • Vertex — Supported. – Cannot be applied to a vertex scoped to an end release. – Vertex selections do not support the Behavior option. • Nodes — Supported. Loading Types: The boundary condition’s loading is defined using one of the following options. • Vector – Supported. While loads are associative with geometry changes, load directions are not. This applies to any load that requires a vector input. The vector load definition displays in the Annotation legend with the label Components. The Magnitude and Direction entries, in any combination or sequence, define these displayed values. These are the values sent to the solver. • Components – Supported. Loading Data Definition: Enter loading data using one of the following options. • Constant — Supported. • Tabular (Time Varying) — Supported. • Tabular (Frequency Varying) — Supported for Harmonic Response Analysis only. By default, at least two frequency entries are required when defining a frequency dependent tabular load. • Tabular (Spatially Varying) — Not Supported. • Function (Time Varying) — Supported. • Function (Spatially Varying) — Not Supported.

Boundary Condition Application You apply a Remote Force as you would apply a force load except that the location of the load origin can be replaced anywhere in space either by picking or by entering the XYZ locations directly. The default location is at the centroid of the geometry. The location and the direction of a remote force can be defined in the global coordinate system or in a local coordinate system. To apply a Remote Force: 1. On the Environment context toolbar: click Loads>Remote Force. Or, right-click the Environment tree object or the Geometry window and select Insert>Remote Force.

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Setting Up Boundary Conditions 2. Define the Scoping Method. 3. Select geometric entities on your model. 4. Specify a coordinate system as needed. The default selection is the Global Coordinate System. You can also specify a user-defined or local coordinate system. 5. Select the method used to define the remote force: Vector (default) or Components. 6. Define the Magnitude, Coordinate System directional loading, and/or Direction of the load based on the above selections. 7. For Harmonic analyses, specify a Phase Angle as needed. 8. Select the Behavior of the geometry. 9. As needed, enter a Pinball Region value. The default value is All.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections. Coordinate System — Drop-down list of available coordinate systems. Global Coordinate System is the default. X Coordinate Y Coordinate Z Coordinate Location

Definition

Type — Read-only field that displays boundary condition type — Remote Force. Define By — Options include:

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Fields/Options/Description • Vector — A magnitude and direction (based on selected geometry). Requires the specification of the following inputs: – Magnitude – Direction • Components — Option to define the loading type as Components (in the world coordinate system or local coordinate system, if applied). Requires the specification of at least one of the following inputs: – X Component — Defines magnitude in the X direction. – Y Component — Defines magnitude in the Y direction. – Z Component — Defines magnitude in the Z direction. Phase Angle (Harmonic Analysis only) Suppressed — Include (No — default) or exclude (Yes) the boundary condition. Behavior — This option dictates the behavior of the attached geometry. Options include: • Rigid — Does not allow the scoped geometry to deform. • Deformable — Allows the scoped geometry to deform. • Coupled — Allows the scoped geometry to have the same DOF solution on its underlying nodes as the remote point location. Follower Load — When set to No (default), the force direction doesn’t change during the simulation. When set to Yes, the force direction is updated with the underlying body. Note that this options is specific to Rigid Dynamics analysis.

Advanced

Pinball Region — Modify the Pinball setting to reduce the number of elements included in the solver.

Bearing Load The Bearing Load boundary condition simulates radial forces only. It is applied on the interior of a cylinder in the radial direction using a coordinate system. If the Mechanical application detects a portion of the load to be in the axial direction, the solver stops the solution and issues an appropriate error message.

Note • If your CAD system split the target cylinder into two or more faces, select all of the faces when defining the Bearing Load.

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Setting Up Boundary Conditions • When analyzing more than one cylinder, be sure that you scope each cylinder with its own Bearing Load boundary condition. Scoping a single Bearing Load to multiple cylinders, as illustrated below, divides the load among the multiple cylindrical faces by area ratio. The example shows a two cylinders where the length on the right cylinders is twice the length of the left cylinder. For the single bearing load applied to the two cylinders, the reactions are proportional to each cylinder’s area as a fraction of the total load area. This can be seen by the Reaction Force results 100.26N versus 204.33N).

• Although loading across multiple steps may appear as an application of tabular loading, you cannot set the magnitude of a bearing load in terms of either tabular or functional data. You must set a constant or ramped magnitude for each step such that one value corresponds to each step.

Analysis Types Bearing Load is available for the following analysis types: • Harmonic Response • Static Structural • Transient Structural

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values.

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Types of Boundary Conditions Dimensional Types • 3D Simulation — Supported. For vector-based loading on a cylindrical face or geometric axis, you define the radial direction by selecting a different piece of geometry on your model that allows you to modify the Direction in the desired direction. • 2D Simulation — Supported. The Bearing Load boundary condition applies a variable distribution of force to a circular edge. Geometry Types: Geometry types supported for the Bearing Load boundary condition include: • Solid — Supported. • Surface/Shell — Not Supported. • Wire Body/Line Body/Beam — Not Supported. Topology: The following topology selection options are supported for Bearing Load. • Body — Not Supported. • Face — Supported. If the loaded face enlarges (e.g., due to a change in parameters), the total load applied to the face remains constant, but the pressure (force per unit area) decreases. • Edge — Supported — 2D Simulation Only • Vertex — Not Supported. • Nodes — Not Supported. Loading Types: The boundary condition’s loading is defined using one of the following options. • Vector — Supported. You define the radial direction for your vector load by selecting a piece of geometry on your model that provides the ability to specify the direction correctly. The vector load definition displays in the Annotation legend with the label Components. The Magnitude and Direction entries, in any combination or sequence, define these displayed values. These are the values sent to the solver. • Components — Supported. While loads are associative with geometry changes, load direction are not. Loading Data Definition: Enter loading data using one of the following options. • Constant — Supported. • Tabular (Time Varying) — Supported.

Note Although loading across multiple steps may appear as an application of tabular loading, you cannot set the magnitude of a bearing load in terms of either tabular or functional data. You must set a constant or ramped magnitude for each step such that one value corresponds to each step.

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Setting Up Boundary Conditions • Tabular (Spatially Varying) — Not Supported. • Function (Time Varying) — Not Supported. • Function (Spatially Varying) — Not Supported.

Boundary Condition Application To apply a Bearing Load: 1. On the Environment context toolbar: click Loads>Bearing Load. Or, right-click the Environment tree object or the Geometry window and select Insert>Bearing Load. 2. Define the Scoping Method. 3. Select the method used to define the bearing load: Vector (default) or Components. 4. Define the Magnitude, Coordinate System directional loading, and/or Direction of the load based on the above selections.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Face, Edge, etc.) and the number of geometric entities (for example: 1 Face, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that describes the object — Bearing Load. Define By — options include: • Vector — A magnitude and direction (based on selected geometry). Requires the specification of the following inputs: – Magnitude – Direction

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Fields/Options/Description • Components — Option to define the loading type as Components (in the world coordinate system or local coordinate system, if applied). Requires the specification of at least one of the following inputs: – Coordinate System — Drop-down list of available coordinate systems. Global Coordinate System is the default. – X Component — Defines magnitude in the X direction. – Y Component — Defines magnitude in the Y direction. – Z Component — Defines magnitude in the Z direction. Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

MAPDL References and Notes The following MAPDL commands, element types, and considerations are applicable for this boundary condition. • Force is applied using the SF,,PRES command. • Element types include: – SURF154 — 3D structural analyses. – SURF153 — 2D structural analyses.

Bolt Pretension This boundary condition applies a pretension load to a cylindrical face, to a straight edge of a line body, to a single body, or to multiple bodies, typically to model a bolt under pretension.

Analysis Types Bolt Pretension is applicable to pure structural or thermal-stress analyses: • Static Structural • Transient Structural

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation — Supported. • 2D Simulation — Supported (Body scoping only).

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Setting Up Boundary Conditions Be sure that a sufficiently fine mesh exists on a face or body that contains a Bolt Pretension boundary condition so that the mesh can be correctly partitioned along the axial direction (that is, at least two elements long). Geometry Types: Geometry types supported for the Bolt Pretension boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported — Line Body Only. Topology: The following topology selection options are supported for Bolt Pretension. • Body — Supported. – Body scoping of a Bolt Pretension load can be to more than one body. In this case all the scoped bodies are cut. There is still only a single Bolt Pretension load created but this feature allows you to apply a bolt load to a bolt that has been cut into several bodies. This feature is illustrated in the following figure.

– Body scoping requires a local Coordinate System object in the tree. The application of the boundary condition is at the origin and along the z-axis (3D) or x-axis (2D) of the local coordinate system. You can place the coordinate system anywhere in the body and reorient the required axis. – Use caution when defining bolt loads by bodies and a coordinate system because the entire body is sliced along the local cutting plane. • Face — Supported. – If you try to apply a preload on the same face more than once, all definitions except the first one are ignored. – For simulating one Bolt Pretension through multiple split faces, you should apply only one Bolt Pretension boundary condition to one of the split faces, as the Bolt Pretension boundary condition slices though the whole cylinder even though only part of the cylinder is selected. – Care should be used when applying a Bolt Pretension boundary condition to a cylindrical face that has bonded contact. There is a possibility that if you apply a Bolt Pretension boundary condition to a

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Types of Boundary Conditions cylinder that had a bonded contact region, the bonded contact will block the ability of the Bolt Pretension to deform properly. – The Bolt Pretension boundary condition should be applied to cylindrical faces that contain the model volume (that is, do not try to apply the Bolt Pretension load to a hole). – The Bolt Pretension boundary condition does not support scoping to a Virtual Cell (merged faces). • Edge — Supported. An option for applying the boundary condition to a line body is to apply it to a single straight edge on the body. The direction of the boundary condition is inferred from the direction of the edge. • Vertex — Not Supported. • Nodes — Not Supported. Loading Types: The boundary condition’s loading is defined using one of the following options. • Load — Applies a force as a preload. A Preload field is displayed where you enter the value of the load in force units. • Adjustment — Applies a length as a pre-adjustment (for example, to model x number of threads). A Preadjustment property displays when Adjustment is selected. Enter the value of the adjustment in length units. It applies the Preadjustment from the solved deformation value of the previous step to the specified Adjustment value of the current step. • Lock — Fixes all displacements. You can set this state for any step except the first step. • Open — Use this option to leave the Bolt Pretension load open so that the load has no effect on the applied step, effectively suppressing the load for the step. Note that in order to avoid convergence issues from having under-constrained conditions, a small load (0.01% of the maximum load across the steps) is applied. You can set this state for any step. • Increment — Applies a length as an incremental adjustment. An Increment field is displayed where you enter the value of the Adjustment in length units. When applied, the specified value gets added to the solved deformation value from the previous step. You can choose this option for any step except the first step.

Note If a solution restart is performed from a substep of a load step that has an Increment specified, the increment value gets added to the solved deformation value at the beginning of the selected restart sub-step.

Loading Data Definition: Bolt Pretension is defined by constant loading data only.

Boundary Condition Application To apply a Bolt Pretension: 1. On the Environment context toolbar: click Loads>Bolt Pretension. Or, right-click the Environment tree object or the Geometry window and select Insert>Bolt Pretension.

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Setting Up Boundary Conditions 2. Define the Scoping Method. 3. Specify how the boundary condition is defined: by Load, Adjustment, or Open

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Face, Edge, etc.) and the number of geometric entities (for example: 1 Face, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections. Coordinate System (Body scoping only) — Drop-down list of available coordinate systems. Global Coordinate System is the default.

Definition

Type — Read-only field that displays boundary condition type — Bolt Pretension. Suppressed — Include (No — default) or exclude (Yes) the boundary condition. Define By — Options include: • Load • Adjustment • Lock • Open • Increment Preload — Visible when the Define By is set to Load. Preadjustment — Visible when the Define By is set to Adjustment. Increment — Visible when the Define By is set to Increment.

Presented below is a model showing a Bolt Pretension load as a preload force and as a pre-adjustment length: 730

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Types of Boundary Conditions

The following animation shows total deformation: The following demo is presented as an animated GIF. Please view online if you are reading the PDF version of the help. Interface names and other components shown in the demo may differ from those in the released product.

Moment This boundary condition distributes a moment «about» (the vector of ) an axis across one or more flat or curved faces, or about one or more edges or vertices. Use the right-hand rule to determine the sense of the moment. A Moment is classified as a remote boundary condition. Refer to the Remote Boundary Conditions (p. 833) section for a listing of all remote boundary conditions and their characteristics.

Analysis Types Moment is available for the following analysis types: • Harmonic Response • Static Structural • Transient Structural

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types

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Setting Up Boundary Conditions • 3D Simulation – Supported. • 2D Simulation – Supported. Geometry Types: Geometry types supported for the Moment boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported.

Note Face and edge selections for the moment load can span multiple parts, however, multiple vertex selections must be of the same part type (solid, 3D surface or line bodies) or the selection is ignored. Topology: The following topology selection options are supported for Moment. • Body — Not Supported. • Face — Supported — 3D only. If a face enlarges (e.g., due to a change in parameters), the total load applied to the face remains constant, but the load per unit area decreases. • Edge — Supported. • Vertex — Supported. This boundary condition cannot be applied to a vertex scoped to an end release. • Nodes — Supported. Loading Types: The boundary condition’s loading is defined using one of the following options. • Vector – Supported. While loads are associative with geometry changes, load directions are not. The vector load definition displays in the Annotation legend with the label Components. The Magnitude and Direction entries, in any combination or sequence, define these displayed values. These are the values sent to the solver. • Components – Supported. Loading Data Definition: Enter loading data using one of the following options. • Constant — Supported. • Tabular (Time Varying) — Supported. • Tabular (Frequency Varying) — Supported for Harmonic Response Analysis only. By default, at least two frequency entries are required when defining a frequency dependent tabular load. • Tabular (Spatially Varying) — Not Supported. • Function (Time Varying) — Supported.

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Types of Boundary Conditions • Function (Spatially Varying) — Not Supported.

Boundary Condition Application To apply a Moment: 1. On the Environment context toolbar: click Loads>Moment. Or, right-click the Environment tree object or the Geometry window and select Insert>Moment. 2. Define the Scoping Method.

Note When specifying the Scoping Method, faces and edges can be scoped to either the geometry where the load is to be applied (Geometry Selection), to a Named Selection, or to a Remote Point. Vertices cannot be scoped to Remote Point.

3. Select the method used to define the moment: Vector (default) or Components. 4. Define the Magnitude, Coordinate System directional loading, and/or Direction of the load based on the above selections. 5. For Harmonic analyses, specify a Phase Angle as needed. 6. Select the Behavior of the geometry. 7. As needed, enter a Pinball Region value. The default value is All.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections. • Remote Point

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Setting Up Boundary Conditions Category

Fields/Options/Description – Remote Point — Visible when the Scoping Method is set to Remote Point. This field provides a drop-down list of available user–defined Remote Points.

Definition

Type — Read-only field that displays boundary condition type — Moment. Define By (3D Only) — Options include: • Vector — A magnitude and direction (based on selected geometry). Requires the specification of the following inputs: – Magnitude – Direction • Components — Option to define the loading type as Components (in the world coordinate system or local coordinate system, if applied). Requires the specification of at least one of the following inputs: – Coordinate System — Drop-down list of available coordinate systems. Global Coordinate System is the default. – X Component — Defines magnitude in the X direction. – Y Component — Defines magnitude in the Y direction. – Z Component — Defines magnitude in the Z direction. Magnitude (2D Only) Phase Angle (Harmonic Analysis only) Suppressed — Include (No — default) or exclude (Yes) the boundary condition. Behavior — This option dictates the behavior of the attached geometry. Options include: • Rigid — Does not allow the scoped geometry to deform. • Deformable — Allows the scoped geometry to deform. • Coupled — Allows the scoped geometry to have the same DOF solution on its underlying nodes as the remote point location.

Advanced

Pinball Region

Generalized Plane Strain This boundary conditions is used during 2D simulations involving generalized plane strain behavior.

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Types of Boundary Conditions

Analysis Types The Generalized Plane Strain boundary condition is available for the following analysis types: • Modal Analysis • Linear Buckling • Harmonic Response • Static Structural • Transient Structural

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation — Not Supported. • 2D Simulation — Supported. Geometry Types: Geometry types supported for the Generalized Plane Strain boundary condition include: • Solid — Not Supported. • Surface/Shell — Supported — 2D Surface Only. • Wire Body/Line Body/Beam — Not Supported. Topology: The following topology selection options are supported for Generalized Plane Strain. • Body — Supported — All Bodies. • Face — Not Supported. • Edge — Not Supported. • Vertex — Not Supported. • Nodes — Not Supported. Loading Types and Loading Data Definition: The Generalized Plane Strain boundary condition is defined as a constant.

Boundary Condition Application To apply a Generalized Plane Strain: 1. On the Environment context toolbar, click Loads>Generalized Plane Strain. Or, right-click the Environment tree object or in the Geometry window and select Insert>Generalized Plane Strain.

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Setting Up Boundary Conditions 2. The Geometry selection for this boundary condition is, by default, set to All Bodies and is a read-only property. 3. Define the X Coordinate of Reference Point and the Y Coordinate of Reference Point. These entries are distance values defining the starting point in space. 4. Define the properties for the Condition Along Fiber Direction, that includes options for the Boundary Condition property and a Magnitude as applicable. • Free — No magnitude. • Force — Enter magnitude. • Displacement — Enter magnitude. 5. Define the properties for the Condition for Rotation About X-axis and the Condition for Rotation About Y-axis. The options for the include Boundary Condition property are listed below. Magnitude is defined when applicable. • Free — No magnitude. • Moment — Enter magnitude. • Rotation — Enter magnitude.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Geometry — Read-only field that displays geometry selection — All Bodies

Definition

Coordinate System — Drop-down list of available coordinate systems. Global Coordinate System is the default. X Coordinate of Reference Point Y Coordinate of Reference Point Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

Condition for Rotation About X-axis

Boundary Condition — options include: • Free — No magnitude. • Moment — Enter magnitude. • Rotation — Enter magnitude. Magnitude

Condition for Rotation About Y-axis

Boundary Condition — options include: • Free — No magnitude. • Moment — Enter magnitude.

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Types of Boundary Conditions Category

Fields/Options/Description • Rotation — Enter magnitude. Magnitude

Note You may wish to review the Generalized Plain Strain Probes section of the Help for additional information about this boundary condition.

Line Pressure For 3D simulations, a line pressure load applies a distributed force on one edge only, using force density loading in units of force per length. You can define the force density on the selected edge in various ways.

If a pressurized edge enlarges due to a change in CAD parameters, the total load applied to the edge increases, but the pressure (force per unit length) remains constant.

Analysis Types Line Pressure is available for the following analysis types: • Explicit Dynamics • Harmonic Response • Static Structural • Transient Structural

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation — Supported. • 2D Simulation — Not Supported. Geometry Types: Geometry types supported for the Line Pressure boundary condition include: • Solid — Supported. • Surface/Shell — Supported. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions • Wire Body/Line Body/Beam — Supported. Topology: The following topology selection options are supported for Line Pressure. • Body — Not Supported. • Face — Not Supported. • Edge — Supported. • Vertex — Not Supported. • Nodes — Not Supported. Loading Types: The boundary condition’s loading is defined using one of the following options. • Vector — Supported. The vector load definition displays in the Annotation legend with the label Components. The Magnitude and Direction entries, in any combination or sequence, define these displayed values. These are the values sent to the solver. • Tangential — Supported. • Components — Supported. Loading Data Definition: Enter loading data using one of the following options. • Constant — Supported. • Tabular (Time Varying) — Supported. • Tabular (Spatially Varying) — Supported for Tangential loading only • Function (Time Varying) — Supported. • Function (Spatially Varying) — Supported for Tangential loading only.

Boundary Condition Application To apply a Line Pressure: 1. On the Environment context toolbar: click Loads>Line Pressure. Or, right-click the Environment tree object or the Geometry window and select Insert>Line Pressure. 2. Define the Scoping Method. 3. Select the method used to define the Line Pressure: Vector (default), Tangential, or Components. 4. Define the Magnitude, Coordinate System, and/or Direction of the Line Pressure based on the above selections. 5. For Harmonic analyses, specify a Phase Angle as needed.

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Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that displays boundary condition type — Line Pressure. Define By — Options include: • Vector — A magnitude and direction (based on selected geometry). Requires the specification of the following inputs: – Magnitude – Direction • Tangential • Components — Option to define the loading type as Components (in the world coordinate system or local coordinate system, if applied). Requires the specification of at least one of the following inputs: – Coordinate System — Drop-down list of available coordinate systems. Global Coordinate System is the default. – X Component — Defines magnitude in the X direction. – Y Component — Defines magnitude in the Y direction. – Z Component — Defines magnitude in the Z direction. Phase Angle (Harmonic Analysis only) Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

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Setting Up Boundary Conditions

MAPDL References and Notes The following MAPDL commands, element types, and considerations are applicable for this boundary condition. • Line pressure is applied using the SFE command and the SURF156 element type. • Magnitude (constant, tabular, and function) is always represented as one or more tables in the input file.

PSD Base Excitation PSD Base Excitation loads are used exclusively in random vibration analyses to provide excitation in terms of spectral value vs. frequency to your choice of the supports that were applied in the prerequisite modal analysis. The Boundary Condition setting in the Details view includes a drop down list where you can specify any of the following supports for excitation that are defined in the modal analysis: Fixed Support, Displacement, Remote Displacement, and Body-to-Ground Spring. If multiple fixed supports or multiple remote displacements are defined in the modal analysis, you can apply the excitation load to all fixed supports or all remote displacements or all of both loads using one of the following options: • All Fixed Supports • All Remote Displacements • All Supports

Note • Only fixed degrees of freedom of the supports are valid for excitations. • Boundary conditions defined with a local coordinate system are not supported.

You can also specify the excitation direction (X Axis, Y Axis, or Z Axis). The user-defined PSD data table is created in the Tabular Data window. You can create a new PSD table or import one from a library that you have created, via the fly-out of the Load Data option in the Details view.

Note Only positive table values can be input when defining this load. When creating PSD loads for a Random Vibration analysis in the Mechanical application, Workbench evaluates your entries by performing a «Goodness of Fit» to ensure that your results will be dependable. Click the fly-out of the Load Data option and choose Improved Fit after entering data points for viewing the graph and updating the table. Interpolated points are displayed if they are available from the goodness of fit approximation. Once load entries are entered, the table provides one of the following color-code indicators per segment: • Green — Values are considered reliable and accurate.

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Types of Boundary Conditions • Yellow — This is a warning indicator. Results produced are not considered to be reliable and accurate. • Red — Results produced are not considered trustworthy. If you choose to solve the analysis, the Mechanical APDL application executes the action, however; the results are almost certainly incorrect. It is recommended that you modify your input PSD loads prior to the solution process. Four types of base excitation are supported: • PSD Acceleration • PSD G Acceleration • PSD Velocity • PSD Displacement The direction of the PSD base excitation is defined in the nodal coordinate of the excitation points. Multiple PSD excitations (uncorrelated) can be applied. Typical usage is to apply three different PSDs in the X, Y, and Z directions. Correlation between PSD excitations is not supported.

RS Base Excitation RS Base Excitation loads are used exclusively in response spectrum analyses to provide excitation in terms of a spectrum. For each spectrum value, there is one corresponding frequency. Use the Boundary Condition setting in the Details view to apply an excitation to all of the fixed supports that were applied in the prerequisite modal analysis.

Note Only fixed DOFs of the supports are valid for excitations. You can also specify the excitation in a given direction (X Axis, Y Axis, or Z Axis). The user-defined RS data table is created in the Tabular Data window. You can create a new RS table or import one from a library that you have created, via the fly-out of the Load Data option in the Details view.

Note Only positive table values can be used when defining this load. Three types of base excitation are supported: • RS Acceleration • RS Velocity • RS Displacement You should specify the direction of the RS base excitation in the global Cartesian system. Multiple RS excitations (uncorrelated) can be applied. Typical usage is to apply 3 different RS excitations in the X, Y, and Z directions. Correlation between RS excitations is not supported. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions The following additional settings are included in the Details view of an RS Base Excitation load: • Scale Factor: Scales the entire table of input excitation spectrum for a Single Point response spectrum. The factor must be greater than 0.0. The default is 1.0. • Missing Mass Effect: Set to Yes to include the contribution of high frequency modes in the total response calculation. Including these modes is normally required for nuclear power plant design. The responses contributed by frequency modes higher than those of rigid responses, specifically frequency modes beyond Zero Period Acceleration (ZPA) are called residual rigid responses. The frequency modes beyond ZPA are defined as frequency modes at which the spectral acceleration returns to the Zero Period Acceleration. In some applications, especially in the nuclear power plant industry, it is critical and required to include the residual rigid responses to the total responses. Ignoring the residual rigid responses will result in an underestimation of responses in the vicinity of supports. There are two methods available to calculate residual rigid responses: the Missing Mass and Static ZPA methods. The Missing Mass method is named based on the fact that the mass associated with the frequency modes higher than that of ZPA are missing from the analysis. As a result, the residual rigid responses are sometimes referred to missing mass responses. When set to Yes, the Missing Mass Effect is used in a response spectrum analysis. • Rigid Response Effect: Set to Yes to include rigid responses to the total response calculation. Rigid responses normally occur in the frequency range that is lower than that of missing mass responses, but higher than that of periodic responses. In many cases, it is impractical and difficult to accurately calculate all natural frequencies and mode shapes for use in the response spectrum evaluation. For high-frequency modes, rigid responses basically predominate. To compensate for the contribution of higher modes to the responses, the rigid responses are combined algebraically to the periodic responses, which occur in the low-frequency modes that are calculated using one the methods above. The most widely adopted methods to calculate the rigid responses are the Gupta and Lindley-Yow methods. These two methods are available for a response spectrum analysis under Rigid Response Effect Type when Rigid Response Effect is set to Yes.

Joint Load When you are using joints in a Transient Structural or Rigid Dynamics analysis, you use a Joint Load object to apply a kinematic driving condition to a single degree of freedom on a Joint object. Joint Load objects are applicable to all joint types except fixed, general, universal, and spherical joints. For translation degrees of freedom, the Joint Load can apply a displacement, velocity, acceleration, or force. For rotation degrees of freedom, the Joint Load can apply a rotation, angular velocity, angular acceleration, or moment. The directions of the degrees of freedom are based on the reference coordinate system of the joint and not on the mobile coordinate system. A positive joint load will tend to cause the mobile body to move in the positive degree of freedom direction with respect to the reference body, assuming the mobile body is free to move. If the mobile body is not free to move then the reference body will tend to move in the negative degree of freedom direction for the Joint Load. One way to learn how the mechanism will behave is to use the Configure feature. For the joint with the applied Joint Load, dragging the mouse will indicate the nature of the reference/mobile definition in terms of positive and negative motion. To apply a Joint Load: 1.

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Highlight the Transient environment object and insert a Joint Load from the right mouse button context menu or from the Loads drop down menu in the Environment toolbar. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

Types of Boundary Conditions 2.

From the Joint drop down list in the Details view of the Joint Load, select the particular Joint object that you would like to apply to the Joint Load. You should apply a Joint Load to the mobile bodies of the joint. It is therefore important to carefully select the reference and mobile bodies while defining the joint.

3.

Select the unconstrained degree of freedom for applying the Joint Load, based on the type of joint. You make this selection from the DOF drop down list. For joint types that allow multiple unconstrained degrees of freedom, a separate Joint Load is necessary to drive each one. Further limitations apply as outlined under Joint Load Limitations (p. 743) below. Joint Load objects that include velocity, acceleration, rotational velocity or rotational acceleration are not applicable to static structural analyses.

4.

Select the type of Joint Load from the Type drop down list. The list is filtered with choices of Displacement, Velocity, Acceleration, and Force if you selected a translational DOF in step 3. The choices are Rotation, Rotational Velocity, Rotational Acceleration, and Moment if you selected a rotational DOF.

5.

Specify the magnitude of the Joint Load type selected in step 4 as a constant, in tabular format, or as a function of time using the same procedure as is done for most loads in the Mechanical application. Refer to Defining Boundary Condition Magnitude (p. 848) for further information.

Tip On Windows platforms, an alternative and more convenient way to accomplish steps 1 and 2 above is to drag and drop the Joint object of interest from under the Connections object folder to the Transient object folder. When you highlight the new Joint Load object, the Joint field is already completed and you can continue at step 3 with DOF selection.

6.

As applicable, specify the load step at which you want to lock the joint load by entering the value of the step in the Lock at Load Step field. The default value for this option is zero (0) and is displayed as Never. This feature immobilizes movement of the joint’s DOFs. For example, this option is beneficial when you want to tighten a bolt to an initial torque value (via a Moment Joint Driver on a Revolute Joint) and then lock that joint during a subsequent load step.

Note MAPDL References: This feature makes use of the %_FIX% parameter on the DJ command. When a joint driver with a force or moment load is deactivated, then the lock constraint on the joint is also deleted using the DJDELE command. This happens if the locking occurs before the deactivation.

Joint Load Limitations Some joint types have limitations on the unconstrained degrees of freedom that allow the application of joint loads as illustrated in the following table: Joint Type Fixed

Unconstrained Degrees of Freedom

Allowable Degrees of Freedom for Applying Joint Loads

None

Not applicable

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Setting Up Boundary Conditions Joint Type

Unconstrained Degrees of Freedom

Allowable Degrees of Freedom for Applying Joint Loads

Revolute

ROTZ

ROTZ

Cylindrical

UZ, ROTZ

UZ, ROTZ

Translational

UX

UX

Slot

UX, ROTX, ROTY, ROTZ

UX

Universal

ROTX, ROTZ

None

Spherical

ROTX, ROTY, ROTZ

None

Planar

UX, UY, ROTZ

UX, UY, ROTZ

General

UX, UY and UZ, Free X, Free Y, Free Z, and Free All

All unconstrained degrees of freedom

Bushing

UX, UY, UZ, ROTX, ROTY, ROTZ

All unconstrained degrees of freedom

Point on Curve

UX

UX

Note Where applicable, you must define all three rotations for a Joint Load before proceeding to a solve.

Thermal Condition You can insert a known temperature (not from data transfer) boundary condition in an analysis by inserting a Thermal Condition object and specifying the value of the temperature in the Details view under the Magnitude property. If the load is applied to a surface body, by default the temperature is applied to both the top and bottom surface body faces. You do have the option to apply different temperatures to the top and bottom faces by adjusting the Shell Face entry in the details view. When you apply a thermal condition load to a solid body, the Shell Face property is not available in the Details view. You can add the thermal condition load as time-dependent or spatially varying.

Note • When a Thermal Condition is specified on the Top or Bottom shell face of a surface body, the opposite face defaults to the environment temperature unless it is otherwise specified from another load object. • For an assembly of bodies with different topologies (solid body, line, shell, beam), you must define a separate Thermal Condition load for each topology, that is, you must define one load scoped to line bodies, define a second load scoped to surface bodies, and so on. • For each load step, if an Imported Body temperature load and a Thermal Condition load are applied on common geometry selections, the Imported Body temperature load takes precedence. See Activation/Deactivation of Loads (p. 637) for additional rules when multiple load objects of the same type exist on common geometry selections. • If the Thermal Condition is applied to a shell face that has a Layered Section applied to it, you must set Shell Face to Both in order to solve the analysis.

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Types of Boundary Conditions

Analysis Types Thermal Condition is available for the following analysis types: • Electric Analysis • Static Structural • Transient Structural

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation – Supported. • 2D Simulation – Supported. Geometry Types: Geometry types supported for the Thermal Condition boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported. Topology: The following topology selection options are supported for Thermal Condition. • Body — Supported. The Thermal Condition is a body-based boundary condition. • Face — Not Supported. • Edge — Not Supported. • Vertex — Not Supported. • Nodes — Not Supported. Loading Types: The Thermal Condition boundary condition’s loading is defined by Magnitude only. Loading Data Definition: Enter loading data using one of the following options. • Constant • Tabular (Time Varying) • Tabular (Spatially Varying) • Function (Time Varying) • Function (Spatially Varying)

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Setting Up Boundary Conditions

Boundary Condition Application To apply a Thermal Condition: 1. On the Environment context toolbar: click Loads>Thermal Condition. Or, right-click the Environment tree object or the Geometry window and select Insert>Thermal Condition. 2. Define the Scoping Method. For Geometry Selection, only surface body faces, solid bodies or line bodies can be selected. For surface bodies, in the Details view, click the Shell Face list, and then select Top, Bottom, or Both (Default) to apply the thermal condition to the selected face. For bodies that have one or more layered section objects, you need to specify Both for Shell Face or the Thermal Condition will be under-defined and an error message will be generated. 3. Define the Magnitude, Coordinate System, and/or Direction of the Thermal Condition based on the above selections.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that displays boundary condition type — Thermal Condition. Magnitude — Temperature value. The default is 22 degrees Celsius. Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

MAPDL References and Notes The following MAPDL commands, element types, and considerations are applicable for this boundary condition.

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Types of Boundary Conditions • Temperatures are applied using the BF command. For surface bodies, with Top or Bottom Shell Face selection, temperatures are applied using the BFE command. • Magnitude (constant, tabular, and function) is always represented as a table in the input file.

Temperature This boundary condition simulates a uniform, time-dependent, or spatially varying temperature over the selected geometry. A spatially varying load allows you to vary the magnitude of a temperature in a single coordinate direction and as a function of time using the Tabular Data or Function features. See the Defining Boundary Condition Magnitude (p. 848) section for the specific steps to apply tabular and/or function loads.

Note For each load step, if an Imported Temperature load and a Temperature load are applied on common geometry selections, the Imported Temperature load takes precedence. See Activation/Deactivation of Loads (p. 637) for additional rules when multiple load objects of the same type exist on common geometry selections.

Analysis Types Temperature is available for the following analysis types: • Steady-State Thermal Analysis • Transient Thermal Analysis • Thermal-Electric Analysis

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation – Supported. • 2D Simulation – Supported — Plane Stress and Axisymmetric behaviors only. Geometry Types: Geometry types supported for the Temperature boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported. Topology: The following topology selection options are supported for Temperature. • Body — Supported. When scoping a load to a body, you need to specify whether the temperature is applied to Exterior Faces Only or to the Entire Body using the Apply To option. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions • Face — Supported. • Edge — Supported. • Vertex — Supported. • Nodes — Not Supported.

Note The same temperature value is applied when multiple faces, edges, or vertices are selected. Loading Types: The Temperature boundary condition’s loading is defined by Magnitude only. Loading Data Definition: Enter loading data using one of the following options. • Constant • Tabular (Time Varying) • Tabular (Spatially Varying) • Function (Time Varying) • Function (Spatially Varying)

Boundary Condition Application To apply a Temperature: 1. On the Environment context toolbar: click Loads>Temperature. Or, right-click the Environment tree object or the Geometry window and select Insert>Temperature. 2. Define the Scoping Method and a geometry selection. 3. Enter a Magnitude for the Temperature.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools.

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Types of Boundary Conditions Category

Fields/Options/Description • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections. Apply To (Body scoping only) — Options include: • Exterior Faces Only • Entire Body

Definition

Type — Read-only field that displays boundary condition type — Temperature. Magnitude — Temperature value. The default is 22o Celsius. Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

MAPDL References and Notes The following MAPDL commands, element types, and considerations are applicable for this boundary condition. • Temperatures are applied using the D command. • Magnitude (constant, tabular, and function) is always represented as a table in the input file.

Convection This boundary condition causes convective heat transfer to occur through one or more flat or curved faces (in contact with a fluid). The bulk fluid temperature is measured at a distance from the face outside of the thermal boundary layer. The face temperature refers to the temperature at the face of the simulation model.

Convective Heat Transfer Convection is related to heat flux by use of Newton’s law of cooling: q/A = h(ts — tf) where: • q/A is heat flux out of the face (calculated within the application) • h is the film coefficient (you provide) • ts is the temperature on the face (calculated within the application) • tf is the bulk fluid temperature (you provide)

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Setting Up Boundary Conditions When the fluid temperature exceeds face temperature, energy flows into a part. When the face temperature exceeds the fluid temperature, a part loses energy. If you select multiple faces when defining convection, the same bulk fluid temperature and film coefficient is applied to all selected faces.

Analysis Types Convection is available for the following analysis types: • Steady-State Thermal Analysis • Thermal-Electric Analysis • Transient Thermal Analysis

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation – Supported. • 2D Simulation – Supported — Plane Stress and Axisymmetric behaviors only. Geometry Types: Geometry types supported for the Convection boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Not Supported. Topology: The following topology selection options are supported for Convection. • Body — Supported (3D Only). • Face — Supported. • Edge — Not Supported. • Vertex — Not Supported. • Nodes — Not Supported. Loading Options: • Film Coefficient — The film coefficient (also called the heat transfer coefficient or unit thermal conductance) is based on the composition of the fluid in contact with the face, the geometry of the face, and the hydrodynamics of the fluid flow past the face. It is possible to have a time, temperature or spatially dependent film coefficient. Refer to heat transfer handbooks or other references to obtain appropriate values for film coefficient.

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Types of Boundary Conditions • Coefficient Type — This field is available when the film coefficient is temperature dependent. Its value can be evaluated at the average film temperature (average of surface and bulk temperatures), the surface temperature, the bulk temperature, or the absolute value of the difference between surface and bulk temperatures.

Note If you change the units from Celsius to Fahrenheit, or Fahrenheit to Celsius, when the convection coefficient type Difference between surface and bulk is in use, the displayed temperature values indicate a temperature difference only. The addition or subtraction of 32o for each temperature in the conversion formula offset one another. In addition, switching to or from the Difference between surface and bulk Coefficient Type option from any other option, clears the values in the Convection Coefficient table. This helps to ensure that you enter correct temperature values.

• Ambient Temperature — The ambient temperature is the temperature of the surrounding fluid. It is possible to have a time or spatially dependent ambient temperature. • Convection Matrix — Specifies whether to use a diagonal film coefficient matrix or a consistent film coefficient matrix. The default setting, Program Controlled, allows the solver to determine whether to use a diagonal or consistent film coefficient matrix. • Edit Data For — This field allows you to select and edit Film Coefficient or Ambient Temperature. The tabular data, details view, graph and graphics view will change based on the selection in the Edit Data For field. For example, when film coefficient is tabular/function and Edit Data For is Film Coefficient, you will actively edit data for the Film Coefficient in the appropriate details view and tabular data fields. Loading Data Definition: Enter loading data using one of the following options. • Constant. • Tabular (Time Varying). • Tabular (Spatially Varying). • Tabular (Temperature Varying) — for Film Coefficient. • Function (Time Varying). • Function (Spatially Varying). You can vary the magnitude of film coefficient and ambient temperature in a single coordinate direction using either tabular data or a function. See the Defining Boundary Condition Magnitude (p. 848) section for the specific steps to apply tabular and/or function loads.

Note Scaling based on time is not supported for convection.

Boundary Condition Application To apply a Convection: Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions 1. On the Environment context toolbar: click Loads>Convection. Or, right-click the Environment tree object or the Geometry window and select Insert>Convection. 2. Define the Scoping Method. 3. Enter a Film Coefficient for the Convection. 4. Modify the Ambient Temperature as needed. 5. Define the Convection Matrix as Program Controlled (default), Diagonal, or Consistent.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Faces) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that displays boundary condition type — Temperature. Film Coefficient Coefficient Type (visible only for temperature dependent Film Coefficient) Ambient Temperature Convection Matrix • Program Controlled (default) • Diagonal • Consistent Edit Data For Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

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Types of Boundary Conditions

MAPDL References and Notes The following MAPDL commands, element types, and considerations are applicable for this boundary condition. • Convection loading is applied using the element types SURF152 (3D thermal analyses) and SURF151 (2D thermal analyses). • Film Coefficient and Ambient Temperature are applied using the SF command. • Film Coefficient and Ambient Temperature (constant, tabular, and function) are always represented as tables in the input file.

Radiation Applies thermal radiation to a surface of a model (an edge in a 2D model). You can define the exchange of radiation between a body and the ambient temperature, or between two surfaces. For thermal related analyses that use the ANSYS solver, the actual calculation of the radiation exchange between two surfaces is performed using the Radiosity Solver method. The Radiosity Solver method accounts for the heat exchange between radiating bodies by solving for the outgoing radiative flux for each surface, when the surface temperatures for all surfaces are known. The surface fluxes provide boundary conditions to the finite element model for the conduction process analysis in Workbench. When new surface temperatures are computed, due to either a new time step or iteration cycle, new surface flux conditions are found by repeating the process. The surface temperatures used in the computation must be uniform over each surface facet to satisfy the conditions of the radiation model. For models that are entirely symmetrical, you can account for symmetry using Symmetry Regions or Cyclic Regions. The Radiosity Solver method respects plane or cyclic symmetries. Using a model’s symmetry can significantly reduce the size of the model. The Radiosity Solver method will take symmetry into account and the Radiation Probe solution results will be valid for the full model. Settings for the Radiosity Solver method are available under the Analysis Settings object in the Radiosity Controls category.

Related References See the sections of the Mechanical APDL help listed below for further information related to using the Radiation load in thermal related analyses that employ the ANSYS solver.

Analysis Types Radiation is available for the following analysis types: • Steady-State Thermal Analysis • Thermal-Electric Analysis • Transient Thermal Analysis

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions Dimensional Types • 3D Simulation — Supported. • 2D Simulation — Supported. Geometry Types: Geometry types supported for the Radiation boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Not Supported. Topology: The following topology selection options are supported for Radiation. • Body — Not Supported. • Face — Supported — 3D Only. • Edge — Supported — 2D Only. • Vertex — Not Supported. • Nodes — Not Supported. Loading Data Definition: Enter loading data using one of the following options. • Constant- Supported. • Tabular (Time Varying) — for Ambient Temperature. — Supported. • Tabular (Spatially Varying) — Not Supported. • Tabular (Temperature Varying) — Supported for Emissivity if Correlation = Surface To Surface. • Function (Time Varying). — Supported. • Function — Not Supported.

Loading Types and Loading Definition The unique loading characteristics and definitions for the Radiation boundary condition are described below. Ambient Temperature Radiation When the Correlation is specified as To Ambient in the Details view of a Radiation object, the radiation energy is exchanged with the ambient temperature, that is, the Form Factor 1 is assumed to be 1.0. You can set the following additional radiation properties in the Details view: • Emissivity: The ratio of the radiation emitted by a surface to the radiation emitted by a black body at the same temperature.

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Types of Boundary Conditions • Ambient Temperature: The temperature of the surrounding space.

Note 1

Radiation exchange between surfaces is restricted to gray-diffuse surfaces. Gray implies that emissivity and absorptivity of the surface do not depend on wavelength (either can depend on temperature). Diffuse signifies that emissivity and absorptivity do not depend on direction. For a gray-diffuse surface, emissivity = absorptivity; and emissivity + reflectivity = 1. Note that a black body surface has a unit emissivity. Surface to Surface Radiation When the Correlation property is specified as Surface to Surface in the Details view of a Radiation object, the radiation energy is exchanged between surfaces. In this context, “surface” refers to a face of a shell or solid body in a 3D model, or an edge in a 2D model. You can then specify Emissivity, Ambient Temperature (defined above), Enclosure, and the Enclosure Type. Emissivity must be a positive value that is not greater than 1. Emissivity can also be defined by Tabular Data. You should assign the same Enclosure number to surfaces radiating to each other 1. Specify the Enclosure Type as either Open (default) or Perfect as suited for a simulation of the closed radiation problems. Furthermore, closed radiation problems have no dependence on Ambient Temperature so that property is removed from the Details view during closed problems.

Caution You cannot apply a Surface to Surface Radiation load to a geometric entity that is already attached to another Radiation load. When using the Surface to Surface correlation with shell bodies, the Details view also includes a Shell Face setting that allows you the choice of applying the load to Both faces, to the Top face only, or to the Bottom face only.

Boundary Condition Application To apply a Radiation: 1. On the Environment context toolbar: click Loads>Radiation. Or, right-click the Environment tree object or the Geometry window and select Insert>Radiation. 2. Define the Scoping Method. 3. Modify the Ambient Temperature as needed.

Details View Properties The selections available in the Details view are described below.

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Setting Up Boundary Conditions Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that displays boundary condition type — Radiation. Correlation Emissivity Ambient Temperature (not visible if Correlation = Surface to Surface and Enclosure Type = Perfect) Enclosure (only visible if Correlation = Surface to Surface) Enclosure Type (only visible if Correlation = Surface to Surface)

Note If a solver error occurs when the Enclosure Type is set to Perfect, it is recommended that you change the setting to Open. Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

MAPDL References and Notes These help sections mention the underlying commands and elements used for implementation of the feature in the Mechanical APDL application. They are presented for reference only. To implement the feature in the Mechanical application, you do not need to interact directly with these commands and elements. • Thermal Analysis Guide: – [1] — Definitions – Using the Radiosity Solver Method

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Types of Boundary Conditions • Mechanical APDL Theory Reference: – Radiation – Radiosity Solution Method • For a perfectly closed system, the VFSM command is employed. Mechanical performs the VFSM,,N,1 command for this boundary condition with Perfect enclosure number N.

Heat Flow Heat Flow is available for 3D simulations and 2D simulations for Plane Stress and Axisymmetric behaviors only. See the 2D Analyses section of the Help for the required geometry settings for Plane Stress and Axisymmetric behaviors. Heat flow simulates the transmission of heat across flat or curved surfaces or edges or across a vertex or vertices and as a result adds energy to a body over time.

Perfectly Insulated For a selected face or faces, Heat Flow allows you to specify a Perfectly Insulated load wherein a «no load» insulated condition is applied to the face — that is, zero heat flow. An insulated face is a no load condition meant to override any thermal loads scoped to a body. The heat flow rate is 0 across this face. This load is useful in a case where most of a model is exposed to a given condition (such a free air convection) and only a couple of faces do not share this condition (such as the base of a cup that is grounded). This load overrides thermal loads scoped to a body only. See Resolving Thermal Boundary Condition Conflicts for a discussion on thermal load precedence. Selecting multiple faces insulates all of the faces.

Analysis Types Heat Flow is available for the following analysis types: • Steady-State Thermal Analysis • Thermal-Electric Analysis • Transient Thermal Analysis

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation — Supported. • 2D Simulation — Supported. Geometry Types: Geometry types supported for the Heat Flow boundary condition include: • Solid — Supported.

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Setting Up Boundary Conditions • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported. Topology: The following topology selection options are supported for Heat Flow. • Body — Not Supported. • Face — Supported 3D Only. If you select multiple faces when defining the heat flow rate, the magnitude is apportioned across all selected faces. • Edge — Supported. If you select multiple edges when defining the heat flow rate, the magnitude is apportioned across all selected edges. • Vertex — Supported. If you select multiple vertices when defining the heat flow rate, the magnitude is apportioned among all selected vertices. • Nodes — Not Supported.

Note • If a face enlarges due to a change in CAD parameters, the total load applied to the face remains constant, but the heat flux (heat flow rate per unit area) decreases. • If an edge enlarges due to a change in CAD parameters, the total load applied to the edge remains constant, but the line load (heat flow rate per unit length) decreases. • If you try to apply a heat flow to a multiple face, edge, or vertex selections that span multiple bodies, the selection is ignored. The geometry property for the load object displays No Selection if the load was just created, or it maintains its previous geometry selection if there was one. Those multiple bodies should belong to the same part in order for the selection of multiple faces to be valid for scoping.

Loading Data Definition: Enter loading data using one of the following options. • Constant — Supported. • Tabular (Time Varying) — Supported for face selections in 3D and edge selections in 2D. • Tabular (Spatially Varying) — Not Supported. • Function (Time Varying) — Supported for face selections in 3D and edge selections in 2D. • Function (Spatially Varying) — Not Supported.

Boundary Condition Application To apply a Heat Flow: 1. On the Environment context toolbar: click Loads>Heat Flow. Or, right-click the Environment tree object or the Geometry window and select Insert>Heat Flow. 2. Define the Scoping Method and a geometry selection.

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Types of Boundary Conditions 3. Enter a Magnitude for the Heat Flow.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that displays boundary condition type — Heat Flow. Define As — Heat Flow (default) or Perfectly Insulated. Perfectly Insulated indicates zero heat flow. Magnitude — Loading value. Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

MAPDL References and Notes Convection loading is applied using the element types SURF152 (3D thermal analyses) and SURF151 (2D thermal analyses). • In a 3D analyses, Heat Flow on face selections are applied using the SF,,HFLUX command on SURF152 elements. Heat Flow is represented as a table in the input file. Heat Flow applied to a selected edge or vertex use the F command. • In a 2D analyses Heat Flow on edge selections are applied using the SF,,HFLUX command on SURF151 elements. Heat Flow is represented as a table in the input file. Heat Flow on vertex selections are applied using the F command.

Heat Flux Heat Flux is available for 3D simulations and 2D simulations for Plane Stress and Axisymmetric behaviors only. See the 2D Analyses section of the Help for the required geometry settings for Plane Stress and Axisymmetric behaviors. The Heat Flux boundary condition applies a uniform heat flux to the selected geometry. A positive heat flux acts into a face or edge, adding energy to a body. Heat flux is defined as energy per unit time per

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Setting Up Boundary Conditions unit area. If you select multiple faces or edges when defining the heat flux, the same value gets applied to all selected faces. If a face enlarges due to a change in CAD parameters, the total load applied to the face increases, but the heat flux remains constant.

Analysis Types Heat Flux is available for the following analysis types: • Steady-State Thermal Analysis • Thermal-Electric Analysis • Transient Thermal Analysis

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation – Supported. Body and Face selections only. • 2D Simulation – Supported. Edge selections only. Geometry Types: Geometry types supported for the Heat Flux boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Not Supported. Topology: The following topology selection options are supported for Heat Flux. • Body — Supported — 3D Only. • Face — Supported. • Edge — Supported — 2D Only. • Vertex — Not Supported. • Nodes — Not Supported. Loading Data Definition: Enter loading data using one of the following options. • Constant — Supported. • Tabular (Time Varying) — Supported. • Tabular (Spatially Varying) — Not Supported. • Function (Time Varying) — Supported.

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Types of Boundary Conditions • Function (Spatially Varying) — Not Supported.

Boundary Condition Application To apply a Heat Flux: 1. On the Environment context toolbar: click Loads>Heat Flux. Or, right-click the Environment tree object or the Geometry window and select Insert>Heat Flux. 2. Define the Scoping Method and a geometry selection. 3. Enter a Magnitude for the Heat Flux.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that displays boundary condition type — Heat Flux. Magnitude — Heat flux density value. Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

MAPDL References and Notes The following MAPDL commands, element types, and considerations are applicable for this boundary condition. • Heat Flux is applied using the SF command and SURF152 (3D thermal analyses) and SURF151 (2D thermal analyses) element types. • Heat Flux (constant, tabular, and function) is always represented as a table in the input file.

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Setting Up Boundary Conditions

Internal Heat Generation Available for 3D simulations, and 2D simulations for Plane Stress and Axisymmetric behaviors only. See the 2D Analyses section of the Help for the required geometry settings for Plane Stress and Axisymmetric behaviors. Applies a uniform generation rate internal to a body. A positive heat generation acts into a body, adding energy to it. Heat generation is defined as energy per unit time per unit volume. If you select multiple bodies when defining the heat generation, the same value gets applied to all selected bodies. If a body enlarges due to a change in CAD parameters, the total load applied to the body increases, but the heat generation remains constant.

Note For each load step, if an Imported Heat Generation load and an Internal Heat Generation load are applied on common geometry selections, the Imported Heat Generation load takes precedence. See Activation/Deactivation of Loads (p. 637) for additional rules when multiple load objects of the same type exist on common geometry selections.

Analysis Types Internal Heat Generation is available for the following analysis types: • Steady-State Thermal Analysis • Thermal-Electric Analysis • Transient Thermal Analysis

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation — Supported. • 2D Simulation — Supported. Geometry Types: Geometry types supported for the Internal Heat Generation boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported. Topology: The following topology selection options are supported for Internal Heat Generation. • Body — Supported.

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Types of Boundary Conditions • Face — Not Supported. • Edge — Not Supported. • Vertex — Not Supported. • Nodes — Not Supported. Loading Data Definition: Enter loading data using one of the following options. • Constant — Supported. • Tabular (Time Varying) — Supported. • Tabular (Spatially Varying) — Not Supported. • Function (Time Varying) — Supported. • Function (Spatially Varying) — Not Supported.

Boundary Condition Application To apply Internal Heat Generation: 1. On the Environment context toolbar: click Loads>Internal Heat Generation. Or, right-click the Environment tree object or the Geometry window and select Insert>Internal Heat Generation. 2. Define the Scoping Method and a geometry selection. 3. Enter a Magnitude value.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

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Setting Up Boundary Conditions Category

Fields/Options/Description

Definition

Type — Read-only field that displays boundary condition type — Internal Heat Generation. Magnitude Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

MAPDL References and Notes The following MAPDL commands, element types, and considerations are applicable for this boundary condition. • Heat Generation is applied using the BFE command. • Heat Generation (constant, tabular, and function) is always represented as a table in the input file.

Voltage A voltage load simulates the application of an electric potential to a body.

Analysis Types Voltage is available for the following analysis types: • Electric Analysis • Thermal-Electric Analysis • Magnetostatic Analysis For each analysis type, you define the voltage by magnitude and phase angle in the Details view, according to the following equation. V = Vocos(ωt+φ) Vo is the magnitude of the voltage (input value Voltage), ω is the frequency, and φ is the phase angle. For a static analysis, ωt = 0. Magnetostatic Analysis Requirements See Voltage Excitation for Solid Source Conductors (p. 773).

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation — Supported. • 2D Simulation — Supported.

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Types of Boundary Conditions Geometry Types: Geometry types supported for the Voltage boundary condition include: • Solid — Supported. • Surface/Shell — Not Supported. • Wire Body/Line Body/Beam — Not Supported. Topology: The following topology selection options are supported for Voltage. • Body — Not Supported. • Face — Supported. • Edge — Supported. • Vertex — Supported. • Nodes — Not Supported. Loading Data Definition: Enter loading data using one of the following options. • Constant — Supported. • Tabular (Time Varying) — Supported. • Tabular (Spatially Varying) — Not Supported. • Function (Time Varying) — Supported. • Function (Spatially Varying) — Not Supported.

Caution During an Electric/Thermal-Electric Analysis, voltage loads cannot be applied to a face, edge, or vertex that is shared with another voltage or current load or a Coupling.

Boundary Condition Application To apply Voltage: 1. On the Environment context toolbar: click Loads>Voltage. Or, right-click the Environment tree object or the Geometry window and select Insert>Voltage. 2. Define the Scoping Method and a geometry selection. 3. Enter a Magnitude value. 4. Enter a Phase Angle value.

Details View Properties The selections available in the Details view are described below.

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Setting Up Boundary Conditions Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection (default) — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that displays boundary condition type — Voltage. Magnitude Phase Angle Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

MAPDL References and Notes The following MAPDL commands, element types, and considerations are applicable for this boundary condition. • Voltages are applied using the D command. • Magnitude (constant, tabular, and function) is always represented as a table in the input file.

Current A current load simulates the application of an electric current to a body.

Analysis Types Current is available for the following analysis types: • Electric Analysis • Thermal-Electric Analysis • Magnetostatic Analysis For each analysis type, you define the current by magnitude and phase angle in the Details view, according to the following equation.

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Types of Boundary Conditions I = Iocos(ωt+φ) Io is the magnitude of the current (input value Current), ω is the frequency, and φ is the phase angle. For a static analysis, ωt = 0. Magnetostatic Analysis Requirements See Current Excitation for Solid Source Conductors (p. 774) and Current Excitation for Stranded Source Conductors (p. 777).

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation — Supported. • 2D Simulation — Supported. Geometry Types: Geometry types supported for the Current boundary condition include: • Solid — Supported. • Surface/Shell — Not Supported. • Wire Body/Line Body/Beam — Not Supported. Topology: The following topology selection options are supported for Current. • Body — Not Supported. • Face — Supported. An applied current assumes that the body surfaces are equipotential. • Edge — Supported. An applied current assumes that the edges are equipotential. • Vertex — Supported. • Nodes — Not Supported.

Note • Current loads assume that the scoped entities are equipotential, meaning they behave as electrodes where the voltage degrees of freedom are coupled and solve for a constant potential.

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Setting Up Boundary Conditions • During an Electric or Thermal Analysis, it is assumed that the material properties of the body provide conductance. A positive current applied to a face, edge, or vertex flows into the body. A negative current flows out of the body.

Caution Current loads cannot be applied to a face, edge, or vertex that is shared with another voltage or current load or a Coupling. Loading Data Definition: Enter loading data using one of the following options. • Constant — Supported. • Tabular (Time Varying) — Supported. • Tabular (Spatially Varying) — Not Supported. • Function (Time Varying) — Supported. • Function (Spatially Varying) — Not Supported.

Boundary Condition Application To apply Current: 1. On the Environment context toolbar: click Loads>Current. Or, right-click the Environment tree object or the Geometry window and select Insert>Current. 2. Define the Scoping Method and a geometry selection. 3. Enter a Magnitude value. 4. Enter a Phase Angle value.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection (default) — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection.

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Types of Boundary Conditions Category

Fields/Options/Description – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that displays boundary condition type — Current. Magnitude Phase Angle Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

MAPDL References and Notes The following MAPDL commands, element types, and considerations are applicable for this boundary condition. • Currents are applied using a combination of F,,AMPS and CP,,VOLT commands. • Magnitude (constant, tabular, and function) is always represented as a table in the input file.

Electromagnetic Boundary Conditions and Excitations You can apply electromagnetic excitations and boundary conditions when performing a Magnetostatic analysis in the Mechanical application. A boundary condition is considered to be a constraint on the field domain. An excitation is considered to be a non-zero boundary condition which causes an electric or magnetic excitation to the system. Boundary conditions are applied to the field domain at exterior faces. Excitations are applied to conductors. • Magnetic Flux Boundary Conditions (p. 769) • Conductor (p. 771) – Solid Source Conductor Body (p. 771) → Voltage Excitation for Solid Source Conductors (p. 773) → Current Excitation for Solid Source Conductors (p. 774) – Stranded Source Conductor Body (p. 775) → Current Excitation for Stranded Source Conductors (p. 777)

Magnetic Flux Boundary Conditions Available for 3D simulations only. Magnetic flux boundary conditions impose constraints on the direction of the magnetic flux on a model boundary. This boundary condition may only be applied to faces. By default, this feature constrains the flux to be normal to all exterior faces.

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Setting Up Boundary Conditions Selecting Flux Parallel forces the magnetic flux in a model to flow parallel to the selected face. In the figure below, the arrows indicate the direction of the magnetic flux. It can be seen that the flux flows parallel to the xy plane (for any z coordinate).

A flux parallel condition is required on at least one face of the simulation model. It is typically applied on the outer faces of the air body to contain the magnetic flux inside the simulation domain or on symmetry plane faces where the flux is known to flow parallel to the face. To set this feature, right-click on the Magnetostatic environment item in the tree and select Magnetic Flux Parallel from the Insert context menu or click on the Magnetic Flux Parallel button in the toolbar. It can only be applied to geometry faces and Named Selections (faces).

Half-symmetry model of a keepered magnet system. Note that the XY-plane is a Flux Parallel boundary. The flux arrows flow parallel to the plane.

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Types of Boundary Conditions

Half-symmetry model of a keepered magnet system. Note that the YZ-plane is a Flux Normal boundary. The flux arrows flow normal to the plane. This is a natural boundary condition and requires no specification.

Note Applying the flux parallel boundary conditions to the exterior faces of the air domain may artificially capture more flux in the simulation domain than what physically occurs. This is because the simulation model truncates the open air domain. To minimize the effect, ensure the air domain extends far enough away from the physical structure. Alternatively, the exterior faces of the air domain may be left with an unspecified face boundary condition. An unspecified exposed exterior face imposes a condition whereby the flux flows normal to the face. Keep in mind that at least one face in the model must have a flux parallel boundary condition.

Conductor Available for 3D simulations only. A conductor body is characterized as a body that can carry current and possible excitation to the system. Solid CAD geometry is used to model both solid source conductors and stranded source conductors. In solid conductors, such as bus bars, rotor cages, etc., the current can distribute non-uniformly due to geometry changes, hence the program performs a simulation that solves for the currents in the solid conductor prior to computing the magnetic field. Stranded source conductors can be used to represent wound coils. Wound coils are used most often as sources of current excitation for rotating machines, actuators, sensors, etc. You may directly define a current for each stranded source conductor body. • Solid Source Conductor Body (p. 771) • Stranded Source Conductor Body (p. 775)

Solid Source Conductor Body This feature allows you to tag a solid body as a solid source conductor for modeling bus bars, rotor cages, etc. When assigned as a solid source conductor, additional options are exposed for applying electrical

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Setting Up Boundary Conditions boundary conditions and excitations to the conductor. These include applying an electrical potential (voltage) or current. To set this condition, right-click the Magnetostatic environment object in the tree and select Source Conductor from the Insert drop-down menu, or click on the Source Conductor button in the toolbar. Select the body you want to designate as a conductor body, then use the Details view to scope the body to the conductor and set Conductor Type to Solid. The default Number of Turns is 1, representing a true solid conductor. A solid source conductor can be used to represent a stranded coil by setting the Number of Turns to > 1. The conductor still computes a current distribution according to the physics of a solid conductor, but in many cases the resulting current density distribution will not significantly effect the computed magnetic field results. This “shortcut” to modeling a stranded conductor allows you to circumvent the geometry restrictions imposed by the stranded conductor bodies and still obtain acceptable results. After defining the conductor body, you may apply voltage and current conditions to arrive at the desired state.

Note Conductors require two material properties: relative permeability and resistivity. They also must not terminate interior to the model with boundary conditions that would allow current to enter or exit the conductor. Termination points of a conductor may only exist on a plane of symmetry.

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Types of Boundary Conditions Only bodies can be scoped to a conductor. Solid conductor bodies must have at least one voltage excitation and either a second voltage excitation or a current excitation. Also, two solid conductor bodies may not ‘touch’ each other, i.e. they must not share vertices, edges, or faces. To establish current in the conductor, you must apply excitation to at least two locations on the conductor, typically at terminals. For example, you could: • apply a voltage drop at two terminals of a conductor body residing at symmetry planes.

• ground one end of a conductor (set voltage to zero) and apply the net current at the terminal’s other end.

Voltage Excitation for Solid Source Conductors This feature allows you to apply an electric potential (voltage) to a solid source conductor body. A voltage excitation is required on a conductor body to establish a ground potential. You may also apply one to apply a non-zero voltage excitation at another location to initiate current flow. Voltage excitations may only be applied to faces of the solid source conductor body and can be defined as constant or time-varying. To apply a voltage excitation to a solid source conductor body, right-click on the Conductor object under the Magnetostatic environment object in the tree whose Conductor Type is set to Solid, and select Voltage from the Insert drop-down menu, or click on the Voltage button in the toolbar. You define the voltage by magnitude and phase angle in the Details view, according to the equation below. V = Vocos(ωt+ϕ)

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Setting Up Boundary Conditions Vo is the magnitude of the voltage (input value Voltage), ω is the frequency, and ϕ is the phase angle. For a static analysis, ωt = 0.

Note Voltage excitations may only be applied to solid source conductor bodies and at symmetry planes.

An applied voltage drop across the terminals of a conductor body will induce a current. In this simple example, the current in the conductor is related to the applied voltage drop, using the equations shown below. ∆V = applied voltage drop, I = current, ρ = resistivity of the conductor (material property), L = length of the conductor, and Area = cross section area of the conductor. ∆V = IR R = (ρ*L)/Area

Current Excitation for Solid Source Conductors This feature allows you to apply a current to a solid source conductor or stranded source conductor body. Use this feature when you know the amount of current in the conductor. To apply a current excitation to a conductor body, right-click on the Conductor object under the Magnetostatic environment object in the tree whose Conductor Type is set to Solid, and select Current from the Insert drop-down menu, or click on the Current button in the toolbar. A positive current applied to a face flows into the conductor body. A negative current applied to a face flows out of the conductor body. For a stranded source conductor, positive current is determined by the y-direction of a local coordinate system assigned to each solid body segment that comprises the conductor. You define the current by magnitude and phase angle in the Details view, according to the equation below. I = Iocos(ωt+ϕ)

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Types of Boundary Conditions Io is the magnitude of the current (input value Current), ω is the frequency, and ϕ is the phase angle. For a static analysis, ωt = 0.

Note Current excitations may only be applied to a face of a solid source conductor body at symmetry planes. An excitation must be accompanied by a ground potential set at another termination point of the conductor body on another symmetry plane. No current may be applied to a conductor body face that is interior to the model domain. The symmetry plane on which the current excitation is applied must also have a magnetic flux-parallel boundary condition.

An applied current to a conductor face will calculate and distribute the current within the conductor body. A ground potential (voltage = 0) must be applied to a termination point of the conductor body. Both the applied current and voltage constraints must be applied at a symmetry plane.

Stranded Source Conductor Body This feature allows you to tag solid multiple bodies as a stranded source conductor for modeling wound coils. When assigned as a stranded source conductor, additional options are exposed for applying electric boundary conditions and current excitation to the conductor. Model a stranded source conductor using only isotropic materials and multiple solid bodies. Local coordinate systems assigned to these bodies (via the Details view) are the basis for determining the direction of the current that you later apply to a stranded source conductor. The model should include a separate solid body to represent each directional “turn” of the conductor. Assign a local coordinate system to each body with the positive current direction as the y-direction for each of the local coordinate systems. An illustration is shown below.

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Setting Up Boundary Conditions

After creating the body segments and assigning coordinate systems, right-click the Magnetostatic environment object in the tree and select Source Conductor from the Insert drop-down menu, or click on the Source Conductor button in the toolbar. Select all body segments, then scope the bodies to the conductor and, in the Details view, set Conductor Type to Stranded, then enter the Number of Turns and the Conducting Area (cross section area of conductor). The stranded conductor is now ready for you to apply a current. A step-by-step example is presented in the Current Excitation for Stranded Source Conductors (p. 777) section.

Note Conductors require two material properties: relative permeability and resistivity. They also must not terminate interior to the model with boundary conditions that would allow current to enter or exit the conductor. Termination points of a conductor may only exist on a plane of symmetry.

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Types of Boundary Conditions

Current Excitation for Stranded Source Conductors Stranded source conductor bodies are applicable to any magnetic field problem where the source of excitation comes from a coil. The coil must have a defined number of coil «turns.» Stranded source body geometry is limited to straight geometry or circular arc geometry sections with constant cross-section (see below) Source loading for a coil is by a defined current (per turn) and a phase angle according to the equation below. = o ω +φ Io is the magnitude of the current (input value Current), ω is the frequency, and ϕ is the phase angle. For a static analysis, ωt = 0. The direction of the current is determined by the local coordinate systems you assign to each of the solid bodies that comprise the stranded source conductor. A positive or negative assigned value of current will be respective to that orientation. Use the following overall procedure to set up a Stranded Source Conductor and apply a current to the conductor: 1. Define local coordinate systems that have the y-direction point in the direction of positive current flow. • Use Cartesian coordinate systems for straight geometry sections and cylindrical coordinate systems for “arc” geometry sections. 2. Assign a local coordinate system to each stranded source conductor body in the Details view of the body under the Geometry folder.

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3. Right-click on the Magnetostatic environment object in the tree and select Source Conductor from the Insert drop down menu, or click on the Source Conductor button in the toolbar. • Scope the Source Conductor to all of the solid bodies. • Set Conductor Type to Stranded. • Enter the Number of Turns and Conducting Area for the conductor. For the Conducting Area, select a face that represents the conductor’s cross-sectional area and read the surface area that displays in the Status Bar located at the bottom of the screen display.

The Source Conductor graphic and Details view listing is shown below.

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Types of Boundary Conditions

4. Right-click on the Conductor object in the tree and select Current from the Insert drop down menu, or click on the Current button in the toolbar. • Set Magnitude as constant or time-varying. • Set Phase Angle.

The Current automatically is scoped to the same bodies as the Source Conductor. The displayed current arrows give you visual validation that the current direction has been properly defined by the assigned local coordinate systems for each conductor body. Changing either the Type of Source Conductor or any coordinate system will invalidate the setup.

Motion Load The application interacts with motion simulation software such as Dynamic Designer™ from MSC, and MotionWorks from Solid Dynamics. This is not the motion feature that is built into the Mechanical application. See the Rigid Dynamics Analysis (p. 216) and Transient Structural Analysis (p. 285) sections for information on the motion features built into the Mechanical application. Motion simulation software allows you to define and analyze the motion in an assembly of bodies. One set of computed results from the motion simulation is forces and moments at the joints between the bodies in the assembly. See Inserting Motion Loads (p. 781) for the procedure on inserting these loads. These loads are available for static structural analyses.

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Single Body Capability Insert Motion Loads is intended to work only with a single body from an assembly. If more than one body is unsuppressed in the Model during Import, you will receive an error message stating that only one body should be unsuppressed.

Frame Loads File The application reads a text file produced by the motion simulation software. This file contains the load information for a single frame (time step) in the motion simulation. To study multiple frames, create multiple environment objects for the Model and import each frame to a separate environment. The frame loads file includes joint forces and inertial forces which «balance» the joint forces and gravity.

Inertial State If the part of interest is a moving part in the assembly, the frame loads file gives the inertial state of the body. This includes gravitational acceleration, translational velocity and acceleration, and rotational velocity and acceleration. Of these inertial «loads» only the rotational velocity is applied in the environment. The remaining loads are accounted for by solving with inertia relief (see below). If the part of interest is grounded (not allowed to move) in the motion simulation, corresponding supports need to be added in the environment before solving.

Joint Loads For each joint in the motion simulation, the frame loads file reports the force data — moment, force, and 3D location — for the frame. Features are also identified so that the load can be applied to the appropriate face(s), edge(s) or vertex(ices) within the application. These features are identified by the user in the motion simulation software before exporting the frame loads file. For all non-zero moments and forces, a corresponding «Moment» and «Remote Force» are attached to the face(s), edge(s) or vertex(ices) identified in the frame loads file. The Remote Force takes into account the moment arm of the force applied to the joint.

Solving with Inertia Relief Inertia relief is enabled when solving an environment with motion loads. Inertia relief balances the applied forces and moments by computing the equivalent translational and rotational velocities and accelerations. Inertia relief gives a more accurate balance than simply applying the inertia loads computed in the motion simulation. Weak springs are also enabled. The computed reaction forces in the weak springs should be negligible. This option will automatically be turned on if you import any motion loads.

Note Material properties have to be manually set to match density used in motion analysis.

Modifying Parts with Motion Loads If you modify a part having a motion load, you should rerun the solution in the motion simulator software (e.g., Dynamic Designer) and re-export the loads to the Mechanical application. Then, in the Mechanical

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Types of Boundary Conditions application, you must update the geometry, delete the load (from the Environment object) and re-insert the motion load.

Modifying Loads You can modify loads that have been inserted, but you should only do so with great care. Modifying loads in the Mechanical application after importing from the motion simulation software will nullify the original loading conditions sets in the motion simulation software. Therefore, you need to examine your results in the Mechanical application carefully.

Inserting Motion Loads You must make sure the files and data are up to date and consistent when analyzing motion loads. Use the following procedure to ensure that the correct loads are applied for a given time frame. To insert motion loads after solving the motion simulation: 1.

Advance the motion simulation to the frame of interest.

2.

Export the frame loads file from the motion software.

3.

Attach the desired geometry.

4.

Choose any structural New Analysis type except Rigid Dynamics and Random Vibration.

5.

Suppress all bodies except the one of interest.

6.

Click the environment object in the tree, then right-click and select Insert> Motion Loads.

7.

Select the Frame Load file that you exported from Dynamic Designer.

8.

Click Solve. If more than one body is unsuppressed in the Model corresponding to the environment object, you will receive an error message at the time of solution stating that only one body should be unsuppressed.

9.

View the results.

The exported loads depend on the part geometry, the part material properties, and the part’s location relative to the coordinate system in the part document. When any of these factors change, you must solve the motion simulation again by repeating the full procedure. Verify that material properties such as density are consistent in the motion simulation and in the material properties. Insert Motion Loads is intended to work with a single body only. Results with grounded bodies (bodies not in motion in the mechanism) are not currently supported. If an assembly feature (such as a hole) is added after Dynamic Designer generates its Joint attachments for FEA, the attachments may become invalid. These attachments can be verified by opening the Properties dialog box for a Joint and selecting the FEA tab. An invalid attachment will have a red «X» through the icon. To correct this problem, manually redefine the joint attachments using the FEA tab in the Joint Properties dialog. A .log file is created when motion loads are imported. This troubleshooting file has the same name (with an .log extension) and file location as the load file. If the .log file already exists, it is overwritten by the new file.

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Fluid Solid Interface A Fluid Solid Interface boundary condition is used to identify the interface where the transfer of loads to and from external fluid solvers CFX or Fluent occur.

Analysis Types Fluid Solid Interface is available for the following analysis types: • Static Structural • Transient Structural • Steady-State Thermal Analysis • Transient Thermal Analysis

Note • A Static Structural analysis coupled with other physics is intended to work with one substep (specified in the Analysis Settings). When a Fluid Solid Interface is present, program controlled sub-stepping will always use one substep regardless of any nonlinearities present. See Steps and Step Controls for Static and Transient Analyses under the Configuring Analysis Settings section of the Help. • When one or more FSI loads are present, any components defined in the MAPDL input file are exported using the CMWRITE command to the file, file.cm, before the solution is completed. This aids the post-processing of results in CFD-Post.

Mechanical — CFX Once Fluid Solid Interfaces are identified, loads are transferred to and from body faces in the Mechanical APDL model using the MFX variant of the ANSYS Multi-field solver (see “Chapter 4. Multi-field Analysis Using Code Coupling” in the Coupled-Field Analysis Guide for details). This solver is accessed from either the Mechanical APDL Product Launcher or CFX-Solver Manager, and requires both the Mechanical APDL and CFX input files. To generate the Mechanical APDL input file, select the Solution object folder in the Mechanical Outline View, and then select Tools> Write Input File. To generate the CFX input file, use the CFX preprocessor, CFX-Pre. Run time-monitoring is available in both the Mechanical APDL Product Launcher and CFX-Solver Manager. Postprocessing of the Mechanical APDL results is available in the Mechanical application, and simultaneous postprocessing of both the Mechanical APDL and CFX results is available in the CFX postprocessor, CFD-Post.

Mechanical Structural — Fluent Fluid-solid interfaces define the interfaces between the solid or shell elements in the Mechanical system and the fluid in the Fluent system. These interfaces are defined on faces in the Mechanical model. Data is exchanged across these interfaces during the execution of the simulation using the System Coupling component of Workbench. System Coupling is the mechanism allowing the Mechanical application and Fluent to send boundary condition results back and forth to one another (one or two-way communication is available).

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Types of Boundary Conditions Mechanical’s Static Structural and Transient Structural systems can be coupled with Fluent for a fluid force and structural displacement analysis, or a fluid-thermal-structural analysis. For more information about settings and elements needed for the thermal-structural analysis, see Thermal-Fluid-Structural Analyses using System Coupling. The integer Interface Number, found in the Details view, is incremented by default each time a new interface is added. This value can be overridden if desired.

Mechanical Thermal — Fluent Fluid-solid interfaces define the interfaces between the thermal solid or shell elements in the Mechanical system and the fluid in the Fluent system. These interfaces are defined on faces in the Mechanical model. Data is exchanged across these interfaces during the execution of the simulation as described in Fluid-Structure Interaction (FSI) — One-Way Transfer Using System Coupling. For transferring temperature and heat flows from Mechanical, interfaces may only be defined on the following types of faces: • On faces having heat fluxes. • On faces having convections. • On faces with a temperature load. • On faces without any loads specified (adiabatic). In this case, only temperatures are exchanged.

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation – Supported. • 2D Simulation – Not Supported. Geometry Types: Geometry types supported for the Fluid Solid Interface boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Not Supported. Topology: The following topology selection options are supported for Fluid Solid Interface. • Body — Not Supported. • Face — Supported. • Edge — Not Supported. • Vertex — Not Supported. • Nodes — Not Supported. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Boundary Condition Application To apply a Fluid Solid Interface: 1. On the Environment context toolbar: click Loads>Fluid Solid Interface. Or, right-click the Environment tree object or the Geometry window and select Insert>Fluid Solid Interface. 2. Define the Scoping Method.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method – Options include: • Geometry Selection – Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry – Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection – Indicates that the geometry selection is defined by a Named Selection. – Named Selection – Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type – Read-only field that displays boundary condition type — Fluid Solid Interface. Interface Number – Incremental value for each new interface. This value can be overridden if desired. Export Results – Thermal analyses only. The default value for this property is No. When this property is set to Yes, thermal data is written to .axdt files for use with External Data and System Coupling, which can connect to Fluent to transfer thermal data to a CFD analysis for a one-way transfer of static data. The file format for an External Data File (.axdt) is described in the External Data File Format Help section in the Workbench User Guide. Data to Transfer [Expert] – The default for this property is Program Controlled. When set to All System Coupling Data Transfers, the fluid solid interface regions can participate in force, displacement, and thermal coupling through System Coupling. You need to set All System Coupling Data Transfers for Mechanical to participate in a thermal-structural analysis. Suppressed – Include (No — default) or exclude (Yes) the boundary condition.

Detonation Point An explosive may be initiated by various methods of delivering energy to it. However whether an explosive is dropped, thermally irradiated, or shocked, either mechanically or through a shock from an 784

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Types of Boundary Conditions initiator (of a more sensitive explosive), initiation of an explosive always goes through a stage in which a shock wave is an important feature. It is assumed that, on initiation, a detonation wave travels away from the initiation point with constant detonation velocity, being refracted around any inert obstacles in the explosive without moving the obstacle, maintaining a constant detonation velocity in the refracted zone and detonating each particle of explosive on arrival at that particle.

Analysis Types Detonation Point is available for an Explicit Dynamics analysis only.

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation — Supported. • 2D Simulation — Not Supported.

Note Detonation Points are not available for the Explicit Dynamics (LS-DYNA Export) system.

Boundary Condition Application 1. On the Environment context toolbar: click Loads>Detonation Point. Or, right-click the Environment tree object or the Geometry window and select Insert>Detonation Point. 2. Specify Location. Multiple detonation points can be added to an analysis. The location of the selected detonation point and the detonation time are displayed in the annotation on the model.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Definition

Burn Instantaneously — When set to Yes, results in initiation of detonation for all elements with an explosive material at the start of the solve. Detonation Time — User can enter the time for initiation of detonation. [Only visible if Burn Instantaneously is set to No.] Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

Location

Enter detonation point coordinates: • X Coordinate

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Fields/Options/Description • Y Coordinate • Z Coordinate Location — User can interactively select detonation location using the vertex/edge/face selection tools: • Select Vertex — Sets X/Y/Z location to vertex location. • Select Edge — Sets X/Y/Z location to centre of edge. • Select Face — Sets X/Y/Z location to centre of face.

Theory The Detonation analysis method used is Indirect Path detonation. Detonation paths are computed by finding either a direct path through explosive regions or by following straight line segments connecting centers of cells containing explosives. Either: Detonation paths will be computed as the shortest route through cells that contain explosive. Or… Detonation paths are computed by finding the shortest path obtained by following straight line segments connecting the centers of cells containing explosive. The correct detonation paths will automatically be computed around wave-shapers, obstacles, corners, etc. Detonation points must lie within the grid. Paths cannot be computed through multiple Parts. If a detonation point is placed in one Part, the detonation from this point cannot propagate to another Part. If this is required, you must place one or more detonation points in the second Part with the appropriate initiation times set to achieve the required detonation. The following illustration outlines the detonation process:

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Types of Boundary Conditions

• Detonation is initiated at a node or plane (user defined) • Detonation front propagates at the Detonation Velocity, D • Cell begins to burn at time T1 • Burning is complete at time T2 • Chemical energy is released linearly from T1 to T2; burn fraction increases from 0.0 to 1.0 over this time The result DET_INIT_TIME can be used to view the initiation times of the explosive material. For example, in the image below, the body on the left side has a detonation point with instantaneous burn defined, and so the entire material has a detonation initiation time of 1×10-6 ms. The second body has a detonation point defined in the lower X, lower Y, lower Z corner, and the detonation time can be seen to vary from 0 ms (i.e. instantaneous detonation) to a value of 0.19555 ms in the corner of the body furthest away from the detonation point. Once detonation is initiated in an element, a value of zero is shown for DET_INIT_TIME.

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The result ALPHA can be used to view the progress of the detonation wave through the material. This corresponds to the burn fraction, which will be a value between zero (no detonation) and one (detonation complete). For the same example, looking at values of alpha at a later stage in the calculation, the detonation wave can clearly be seen in the body on the right as the spherical band of contours showing the value of alpha changing from zero to one. The body on the left has a value of one for the entire body, as it detonated instantaneously.

Support Type Boundary Conditions The boundary conditions contained under the Support heading are listed below. Fixed Supports

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Types of Boundary Conditions Displacement Remote Displacement Velocity Impedance Boundary — Explicit Dynamics only Frictionless Face Compression Only Support Cylindrical Support Simply Supported Fixed Rotation Elastic Support

Fixed Supports This boundary condition prevents one or more: • Flat or curved faces from moving or deforming • Straight or curved edges from moving or deforming. • Vertices from moving.

Analysis Types A Fixed Support is available for the following analysis types: • Explicit Dynamics • Harmonic Response • Modal • Static Structural • Transient Structural

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation — Supported. Fixes one or more faces, edges, or vertices. • 2D Simulation — Supported. Fixes one or more edges or vertices. Geometry Types: Geometry types supported for the Fixed Support boundary condition include: Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported. Topology: The following topology selection options are supported for Fixed Support. • Body — Supported for rigid bodies in an Explicit Analysis. • Face — Supported. • Edge — Supported. A fixed edge is not realistic and leads to singular stresses (that is, stresses that approach infinity near the fixed edge). You should disregard stress and elastic strain values in the vicinity of the fixed edge. • Vertex — Supported. – A fixed vertex fixes both translations and rotations on faces or line bodies. – A fixed vertex is not realistic and leads to singular stresses (that is, stresses that approach infinity near the fixed vertex). You should disregard stress and elastic strain values in the vicinity of the fixed vertex. – This boundary condition cannot be applied to a vertex scoped to an end release. • Nodes — Not Supported.

Note If you are using a surface body model, see the Simply Supported boundary condition section. Scoping Types: The boundary condition does not require a scoping type because no loading data is required. Loading Data Definition: Fixed supports do not have loading data.

Boundary Condition Application To apply a Fixed Support: 1. On the Environment context toolbar: click Supports>Fixed Support. Or, right-click the Environment tree object or the Geometry window and select Insert>Fixed Support. 2. Define the Scoping Method.

Details View Properties The selections available in the Details view are described below.

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Types of Boundary Conditions Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that describes the object — Fixed Support. Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

Displacements Displacements are applied at the geometry level. They require that one or more flat or curved faces or edges or one or more vertices to displace relative to their original location by one or more components of a displacement vector in the world coordinate system or local coordinate system, if applied.

Analysis Types A Displacement is available for the following analysis types: • Explicit Dynamics • Harmonic Response • Modal • Static Structural • Transient Structural

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation – Supported. Displaces one or more faces, edges, or vertices. • 2D Simulation – Supported. Displaces one or more edge or vertices.

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Setting Up Boundary Conditions Geometry Types: Geometry types supported for the Displacement boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported. Topology: The following topology selection options are supported for Displacement. • Body — Supported for rigid bodies in an Explicit Analysis. • Face — Supported. – Non-zero X-, Y-, and Z-components. The face retains its original shape but moves relative to its original location by the specified displacement vector. The enforced displacement of the face causes a model to deform. – For Zero Y-component, no part of the face can move, rotate, or deform in the Y-direction. – For blank (undefined) X- and Z-components, the surface is free to move, rotate, and deform in the XZ plane. • Edge — Supported. – Enforced displacement of an edge is not realistic and leads to singular stresses (that is, stresses that approach infinity near the loaded edge). You should disregard stress and elastic strain values in the vicinity of the loaded edge. – Non-zero X-, Y-, and Z-components. The edge retains its original shape but moves relative to its original location by the specified displacement vector. The enforced displacement of the edge causes a model to deform. – For Zero Y-component, no part of the edge can move, rotate, or deform in the Y-direction. – For blank (undefined) X- and Z-components, the edge is free to move, rotate, and deform in the XZ plane. • Vertex — Supported. – Non-zero X-, Y-, and Z-components. The vertex moves relative to its original location by the specified displacement vector. The enforced displacement of the vertex causes a model to deform. – For Zero Y-component, the vertex cannot move in the Y-direction. – For blank (undefined) X- and Z-components, the vertex is free to move in the XZ plane. – This boundary condition cannot be applied to a vertex scoped to an End Release. • Nodes — Not Supported.

Note • Multiple surfaces, edges, or vertices can be selected.

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Types of Boundary Conditions • Avoid using multiple Displacements on the same face/edge/vertex and on faces/edges/vertices having shared faces/edges/vertices.

Loading Types: The boundary condition’s loading is defined using one of the following options. • Normal To – Supported (3D Faces Only). • Components – Supported. – Entering a zero for a component prevents deformation in that direction. – Entering a blank for a component allows free deformation in that direction. – In a cylindrical coordinate system X, Y, and Z are used for R, Θ, and Z directions. When using a cylindrical coordinate system, non-zero Y displacements are interpreted as translational displacement quantities, ∆Y = R∆Θ. Since they are treated as linear displacements it is a reasonable approximation only, for small values of angular motion ∆Θ. – For Explicit Dynamics analyses, when using a cylindrical coordinate system, the Y the component (that is, Θ direction) of a displacement constraint is defined as a rotation. Loading Data Definition: Enter loading data using one of the following options. • Constant – Supported. • Tabular (Time Varying) – Supported. • Tabular (Spatially Varying) — Not Supported for Explicit Dynamics. • Function (Time Varying) — Not Supported for Explicit Dynamics. • Function (Spatially Varying) — Not Supported for Explicit Dynamics. • Free – Supported.

Note Solution Restarts are only supported for Tabular data modifications.

Boundary Condition Application To apply a Displacement: 1. On the Environment context toolbar: click Supports>Displacement. Or, right-click the Environment tree object or the Geometry window and select Insert>Displacement. 2. Define the Scoping Method. 3. Select the method used to define the Displacement: Components or Normal To. 4. Define the Coordinate System and displacements or the Distance, of the Displacement based on the above selections.

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Setting Up Boundary Conditions 5. For Harmonic analyses, specify a Phase Angle as needed.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that describes the object — Displacement. Define By — Options include: • Normal To — Requires a Distance entry. This is the distance of displacement, that is, a magnitude. • Components — Option to define the loading type as Components (in the world coordinate system or local coordinate system, if applied). Requires the specification of at least one of the following inputs: – Coordinate System — Drop-down list of available coordinate systems. Global Coordinate System is the default. – X Component — Defines distance in the X direction. – Y Component — Defines distance in the Y direction. – Z Component — Defines distance in the Z direction. Phase Angle (Harmonic Analysis only) Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

Remote Displacement A Remote Displacement allows you to apply both displacements and rotations at an arbitrary remote location in space. You specify the origin of the remote location under Scope in the Details view by

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Types of Boundary Conditions picking, or by entering the XYZ coordinates directly. The default location is at the centroid of the geometry. You specify the displacement and rotation under Definition. A Remote Displacement is classified as a remote boundary condition. Refer to the Remote Boundary Conditions (p. 833) section for a listing of all remote boundary conditions and their characteristics.

Analysis Types A Remote Displacement is available for the following analysis types: • Explicit Dynamics • Harmonic Response • Modal. For a Modal analysis, only zero magnitude Remote Displacement values are valid. These function as supports. If non-zero magnitude remote displacements are needed for a Pre-Stress Modal analysis, apply the Remote Displacement in the static structural environment. • Static Structural • Transient Structural • Rigid Dynamics A common application is to apply a rotation on a model at a local coordinate system. An example is shown below along with a plot of the resulting Total Deformation.

Total Deformation Result Example

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Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types • 3D Simulation — Supported. • 2D Simulation — Supported. Geometry Types: Geometry types supported for the Remote Displacement boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported. Topology: The following topology selection options are supported for Remote Displacement. • Body — Not Supported. • Face — Supported. • Edge — Supported. • Vertex — Supported. This boundary condition cannot be applied to a vertex scoped to an end release. • Nodes — Not Supported Loading: This boundary condition’s loading in defined in one or more of the following directions. • X Component • Y Component • Z Component

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Types of Boundary Conditions • X Rotation • Y Rotation • Z Rotation Loading Data Definition: Enter loading data using one of the following options. • Constant — Supported. • Tabular (Time Varying) — Supported. • Function (Time Varying) — Supported. • Free — Supported.

Note Solution Restarts are only supported for Tabular data modifications.

Boundary Condition Application To apply a Remote Displacement: 1. On the Environment context toolbar: click Supports>Remote Displacement. Or, right-click the Environment tree object or the Geometry window and select Insert>Remote Displacement. 2. Define the Scoping Method. 3. Specify the origin of the remote location or enter the XYZ coordinates. The default location is at the centroid of the geometry. 4. Specify the translational and rotational displacement components.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection.

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Setting Up Boundary Conditions Category

Fields/Options/Description – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections. Coordinate System — Drop-down list of available coordinate systems. Global Coordinate System is the default. Z Coordinate Y Coordinate X Coordinate Location — The location of a Remote Displacement can be defined in the global coordinate system or in a local Cartesian coordinate system. It is by default at the centroid of selected geometry.

Definition

Type — Read-only field that describes the object — Remote Displacement. X Component — Defines distance (+/-) in the X direction. Y Component — Defines distance (+/-) in the Y direction. Z Component — Defines distance (+/-) in the Z direction. X Rotation — Defines rotational distance (+/-) in the X direction. Y Rotation — Defines rotational distance (+/-) in the Y direction. Z Rotation — Defines rotational distance (+/-) in the Z direction. Suppressed — Include (No — default) or exclude (Yes) the boundary condition. Behavior: Rigid, Deformable, or Coupled.

Advanced

Pinball Region: Specify the radius of the pinball (length unit). The displacement is applied to the elements that are within the pinball region.

Velocity Analysis Types Velocity is available for the following analysis types: • Explicit Dynamics — For Explicit Dynamics analyses, the Y Component (that is, Θ direction) of a velocity constraint defined with a cylindrical coordinate system has units of angular velocity. • Transient Structural

Common Characteristics This section describes the characteristics of the boundary condition, including the application requirements, support limitations, and loading definitions and values. Dimensional Types

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Types of Boundary Conditions • 3D Simulation – Supported. • 2D Simulation – Supported. Geometry Types: Geometry types supported for the Velocity boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported. Topology: The following topology selection options are supported for Velocity. • Body — Supported. • Face — Supported. • Edge — Supported. • Vertex — Supported. – Avoid using multiple velocities on the same vertex. – This boundary condition cannot be applied to a vertex scoped to an end release. • Nodes — Not Supported. Loading Types: The boundary condition’s loading is defined using one of the following options. • Normal To – Supported (3D Faces Only). • Components – Supported. – Entering a zero for a component sets the velocity to zero. – Entering a blank for a component allows free velocity in that direction. Loading Data Definition: Enter loading data using one of the following options. • Constant • Tabular (Time Varying) • Function (Time Varying) • Free

Boundary Condition Application To apply a Velocity: 1. On the Environment context toolbar: click Supports>Velocity. Or, right-click the Environment tree object or the Geometry window and select Insert>Velocity. 2. Define the Scoping Method.

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Setting Up Boundary Conditions 3. Select the method used to define the Velocity: Components (default) or Normal To. 4. Define the loading data based on the above selections.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that describes the object — Velocity. Define By — Options include: • Normal To — Requires a Magnitude entry. • Components — Option to define the loading type as Components (in the world coordinate system or local coordinate system, if applied). Requires the specification of at least one of the following inputs: – Coordinate System — Drop-down list of available coordinate systems. Global Coordinate System is the default. – X Component — Defines magnitude in the X direction. – Y Component — Defines magnitude in the Y direction. – Z Component — Defines magnitude in the Z direction. Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

Impedance Boundary This boundary condition is available for the explicit solver only. You can use the impedance boundary condition to transmit waves through cell faces. The boundary condition predicts the pressure P in the dummy cell from the impedance, particle velocity and a reference

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Types of Boundary Conditions pressure (P0). Only the perpendicular component is transmitted, as the pressure is spherical. Therefore, the Impedance boundary condition is only approximate, and should be placed as far as possible from region of interest.

Theory In order to economize on problem size it is sometimes advantageous for problems which have only outward traveling solutions (e.g. an expanding high pressure source) to limit the size of the grid by a boundary condition which allows outward traveling waves to pass through it without reflecting energy back into the computational grid.

In practice it proves impossible to include a simple boundary condition which is accurate for all wave strengths but the algorithm used here give a reasonable approximation over a wide spectrum. However it should always be borne in mind that the condition is only approximate and some reflected wave, however small, will be created and care must be taken that such a wave does not have a significant effect on the later solution. Note that the following analysis deals only with the normal component of velocity of the wave and the velocity component parallel to the boundary is assumed to be unaffected by the boundary. For a one-dimensional wave traveling in the direction of increasing x, the conditions on the rearward facing characteristic are

where ρc is the acoustic impedance (ρ is the local density and c is the local sound speed) and dp and du are the changes of pressure and velocity normal to the wave along the characteristic. Since it is assumed that no wave energy is being propagated back in the direction of decreasing x the error in applying the above condition on a non-characteristic direction is in general small and it is applied on the transmitting boundary in the form

Where: uN is the component of mean velocity normal to the boundary [ρc]boundary is the assumed Material Impedance for the boundary pref is the user defined reference pressure

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Setting Up Boundary Conditions uref is the user defined reference velocity at the boundary For an initially stationary structure at zero pressure, the reference values (pref and uref) are normally set to zero. In this case we have

which is exact for a plane elastic longitudinal wave propagating in an infinite elastic medium.

Note The default Material Impedance (Program Controlled) is zero. In this case the impedance at the boundary is taken to be the impedance at time t of the element to which the boundary is applied. This represents the case of perfect transmission of plane normal elastic waves.

Common Characteristics The following section outlines the common boundary condition characteristics that include application requirements of the boundary condition, support limitations, as well as loading definitions and values. Dimensional Types • 3D Simulation — Supported. • 2D Simulation — Supported. Geometry Types: Geometry types supported for the Impedance Boundary boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported. Topology: The following topology selection options are supported for Impedance Boundary. • Body — Not Supported. • Face — Supported. • Edge — Not Supported. • Vertex — Not Supported. • Nodes — Not Supported. Loading Data Definition: Enter loading data using one of the following options.

Boundary Condition Application To apply an Impedance Boundary: 1. On the Environment context toolbar: click Supports>Impedance Boundary. Or, right-click the Environment tree object or the Geometry window and select Insert>Impedance Boundary. 802

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Types of Boundary Conditions 2. Define the Scoping Method.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that describes the object — Impedance Boundary. Material Impedance — Program Controlled or input value. Reference Velocity — Program Controlled or input value. Reference Pressure — Program Controlled or input value. Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

Frictionless Face You use this boundary condition to prevent one or more flat or curved faces from moving or deforming in the normal direction. The normal direction is relative to the selected geometry face. No portion of the surface body can move, rotate, or deform normal to the face. For tangential directions, the surface body is free to move, rotate, and deform tangential to the face. For a flat surface body, the frictionless support is equivalent to a symmetry condition.

Analysis Types A Frictionless Support is available for the following analysis types: • Harmonic Response • Modal • Static Structural Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions • Transient Structural

Common Characteristics The following section outlines the common boundary condition characteristics that include application requirements of the boundary condition, support limitations, as well as loading definitions and values. Dimensional Types • 3D Simulation — Supported. • 2D Simulation — Supported. Geometry Types: Geometry types supported for the Frictionless Support boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported. Topology: The following topology selection options are supported for Frictionless Support. • Body — Not Supported. • Face — Supported — 3D Only. • Edge — Supported — 2D Only. • Vertex — Not Supported. • Nodes — Not Supported.

Boundary Condition Application To apply a Frictionless Support: 1. On the Environment context toolbar: click Supports>Frictionless Support. Or, right-click the Environment tree object or the Geometry window and select Insert>Frictionless Support. 2. Specify Scoping Method and Geometry or Named Selection.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric

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Types of Boundary Conditions Category

Fields/Options/Description entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that describes the object — Frictionless Support. Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

Compression Only Support Applies a compression only constraint normal to one or more faces. It is modeled internally using Asymmetric rigid-flexible contact. A rigid target surface is constructed and/or mirrored from the scoped faces/edges of the Compression Only Support. Therefore, the following points should be kept in mind: • The underlying technology is using penalty-based formulations. As a result, normal contact stiffness can be an important parameter if nonlinear convergence issues arise. Control normal contact stiffness using the Normal Stiffness property of the Compression Only Support object. • Because source and target topologies are perfect mirrors of one another, be careful during nonlinear analyses to make that contact doesn’t “fall off” the target face. Be sure that the contacting area on the rigid body is large enough to accommodate any potential sliding taking place during the analysis. To avoid this, consider using a fully fixed rigid body and a nonlinear contact to replace the compression only support. Consider the following model with a bearing load and supports as shown.

Note the effect of the compression only support in the animation of total deformation. The following demo is presented as an animated GIF. Please view online if you are reading the PDF version of the help. Interface names and other components shown in the demo may differ from those in the released product.

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Setting Up Boundary Conditions

Since the region of the face in compression is not initially known, a nonlinear solution is required and may involve a substantial increase in solution time.

Analysis Types A Compression Only Support is available for the following analysis types: • Harmonic Response • Modal • Static Structural • Transient Structural

Common Characteristics The following section outlines the common boundary condition characteristics that include application requirements of the boundary condition, support limitations, as well as loading definitions and values. Dimensional Types • 3D Simulation – Supported. • 2D Simulation – Supported. Geometry Types: Geometry types supported for the Compression Only Support boundary condition include: • Solid — Supported. • Surface/Shell — Not Supported. • Wire Body/Line Body/Beam — Not Supported. Topology: The following topology selection options are supported for Compression Only Support. • Body — Not Supported. • Face — Supported — 3D Only.

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Types of Boundary Conditions • Edge — Supported — 2D Only. • Vertex — Not Supported. • Nodes — Not Supported.

Boundary Condition Application To apply a Compression Only Support: 1. On the Environment context toolbar: click Supports>Compression Only Support. Or, right-click the Environment tree object or the Geometry window and select Insert>Compression Only Support. 2. Specify Scoping Method and Geometry or Named Selection. 3. Specify Normal Stiffness property. If set to Manual, enter a Normal Stiffness Factor value. 4. Specify Update Stiffness property.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that describes the object — Compression Only Support. Normal Stiffness — Defines a contact Normal Stiffness factor. Options include: • Program Controlled — This is the default setting. The Normal Stiffness Factor is calculated by the program. • Manual — The Normal Stiffness Factor is input directly by the user. The Normal Stiffness Factor property displays for this setting. Update Stiffness — Specify if the program should update (change) the contact stiffness during the solution. Options include:

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Setting Up Boundary Conditions Category

Fields/Options/Description • Never — This is the default setting. Turns off the program’s automatic Update Stiffness feature. • Each Iteration — Sets the program to update stiffness at the end of each equilibrium iteration. • Each Iteration, Aggressive — Sets the program to update stiffness at the end of each equilibrium iteration, but compared to the option, Each Iteration, this option allows for a more aggressive changing of the value range. Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

Cylindrical Support For 3D simulations, this boundary condition prevents one or more cylindrical faces from moving or deforming in combinations of radial, axial, or tangential directions. Any combination of fixed and free radial, axial, and tangential settings are allowed.

Analysis Types A Cylindrical Support is available for the following analysis types: • Harmonic Response • Modal • Static Structural • Transient Structural

Common Characteristics The following section outlines the common boundary condition characteristics that include application requirements of the boundary condition, support limitations, as well as loading definitions and values. Dimensional Types • 3D Simulation – Supported. • 2D Simulation – Supported. Cylindrical supports can only be applied to circular edges Geometry Types: Geometry types supported for the Cylindrical Support boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported. Topology: The following topology selection options are supported for Cylindrical Support. • Body — Not Supported. • Face — Supported — 3D Cylindrical Face Only.

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Types of Boundary Conditions • Edge — Supported — 2D Circular Edge Only. • Vertex — Not Supported. • Nodes — Not Supported.

Boundary Condition Application To apply a Cylindrical Support: 1. On the Environment context toolbar: click Supports>Cylindrical Support. Or, right-click the Environment tree object or the Geometry window and select Insert>Cylindrical Support. 2. Specify Scoping Method and Geometry or Named Selection.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that describes the object — Cylindrical Support. Radial — Fixed (default) or Free. Axial (3D Only) — Fixed (default) or Free. Tangential — Fixed (default) or Free. Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

Simply Supported Available for 3D simulations only.

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Setting Up Boundary Conditions This boundary condition prevents one or more straight or curved edges or a vertex or vertices from moving or deforming. However, rotations are allowed. If you want to fix the rotations as well, use the Fixed Support boundary condition. It is applicable for surface body models or line models only.

Analysis Types A Simply Supported is available for the following analysis types: • Harmonic Response • Modal • Static Structural • Transient Structural

Common Characteristics The following section outlines the common boundary condition characteristics that include application requirements of the boundary condition, support limitations, as well as loading definitions and values. Dimensional Types • 3D Simulation — Supported. • 2D Simulation — Not Supported. Geometry Types: Geometry types supported for the Simply Supported boundary condition include: • Solid — Not Supported. • Surface/Shell — Supported — Surface Only. • Wire Body/Line Body/Beam — Supported — Line Only. Topology: The following topology selection options are supported for Simply Supported. • Body — Not Supported. • Face — Not Supported. • Edge — Supported. • Vertex — Supported. This boundary condition cannot be applied to a vertex scoped to an End Release. In addition, a simply supported vertex is not realistic and leads to singular stresses (that is, stresses that approach infinity near the simply supported vertex). You should disregard stress and elastic strain values in the vicinity of the simply supported vertex. • Nodes — Not Supported.

Boundary Condition Application To apply a Simply Supported: 1. On the Environment context toolbar: click Supports>Simply Supported. Or, right-click the Environment tree object or the Geometry window and select Insert>Simply Supported. 810

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Types of Boundary Conditions 2. Specify Scoping Method and Geometry or Named Selection.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that describes the object — Simply Supported. Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

Fixed Rotation You can apply a Fixed Rotation boundary condition to faces, edges, and vertices of a surface body. When you only apply a fixed rotation support to a surface body, the geometry is free in all translational directions. However, by default, the rotation of the geometry is fixed about the axes of the corresponding coordinate system.

Note • Rotation constraints are combined with other constraints that produce rotational DOF assignments to determine which values to apply. They are combined with all other constraints to determine the Nodal Coordinate System orientation (frictionless supports, cylindrical supports, given displacements, etc.). • There may be circumstances in which the rotational support and other constraints cannot resolve a discrepancy for preference of a particular node’s coordinate system.

Analysis Types A Fixed Rotation is available for the following analysis types: • Harmonic Response

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Setting Up Boundary Conditions • Explicit Dynamics • Modal • Static Structural • Transient Structural

Common Characteristics The following section outlines the common boundary condition characteristics that include application requirements of the boundary condition, support limitations, as well as loading definitions and values. Dimensional Types • 3D Simulation — Supported. • 2D Simulation — Not Supported. Geometry Types: Geometry types supported for the Fixed Rotation boundary condition include: • Solid — Not Supported. • Surface/Shell — Supported — Surface Body only. • Wire Body/Line Body/Beam — Supported. Topology: The following topology selection options are supported for Fixed Rotation. • Body — Not Supported. • Face — Supported. • Edge — Supported. • Vertex — Supported. – A fixed vertex rotation support is not realistic and leads to singular stresses (that is, stresses that approach infinity near the fixed vertex rotation support). You should disregard stress and elastic strain values in the vicinity of the fixed vertex rotation support. – This boundary condition cannot be applied to a vertex scoped to an end release. • Nodes — Not Supported.

Boundary Condition Application To apply a Fixed Rotation: •

In the Details view, select Free or Fixed for Rotation X, Rotation Y, and Rotation Z to define the fixed rotation support.

1. On the Environment context toolbar: click Supports>Fixed Rotation. Or, right-click the Environment tree object or the Geometry window and select Insert>Fixed Rotation. 2. Specify Scoping Method and Geometry or Named Selection.

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Types of Boundary Conditions 3. As needed, specify the coordinate system for the corresponding rotational constraint. 4. Define the rotational axes as Fixed (default) or Free.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that describes the object — Fixed Rotation. Coordinate System — Drop-down list of available coordinate systems. Global Coordinate System is the default. Rotation X — Fixed (default) or Free. Rotation Y — Fixed (default) or Free. Rotation Z — Fixed (default) or Free. Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

Note When parameterizing this boundary condition, a Free axis of rotation is represented by a zero (0) and Fixed with a value of one (1) inside the Parameter tab in ANSYS Workbench (outside of Mechanical).

Elastic Support Allows one or more faces (3D) or edges (2D) to move or deform according to a spring behavior. The Elastic Support is based on a Foundation Stiffness set in the Details view, which is defined as the pressure required to produce a unit normal deflection of the foundation.

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Setting Up Boundary Conditions

Analysis Types An Elastic Support is available for the following analysis types: • Harmonic Response • Modal • Static Structural • Transient Structural

Common Characteristics The following section outlines the common boundary condition characteristics that include application requirements of the boundary condition, support limitations, as well as loading definitions and values. Dimensional Types • 3D Simulation – Supported. • 2D Simulation – Supported. Geometry Types: Geometry types supported for the Elastic Support boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported Topology: The following topology selection options are supported for Elastic Support. • Body — Not Supported. • Face — Supported. • Edge — Supported — 2D Only. • Vertex — Not Supported. • Nodes — Not Supported.

Boundary Condition Application To apply a Elastic Support: 1. On the Environment context toolbar: click Supports>Elastic Support. Or, right-click the Environment tree object or the Geometry window and select Insert>Elastic Support. 2. Specify Scoping Method and Geometry or Named Selection.

Details View Properties The selections available in the Details view are described below.

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Types of Boundary Conditions Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Type — Read-only field that describes the object — Elastic Support. Suppressed — Include (No — default) or exclude (Yes) the boundary condition. Foundation Stiffness

Conditions Type Boundary Conditions The boundary conditions contained under the Conditions heading are listed below. • Coupling • Constraint Equation • Pipe Idealization

Coupling While setting up a model for analysis, you can establish relationships among the different degrees of freedom of the model by physically modeling the part or a contact condition. However, sometimes there is a need to be able to model distinctive features of a geometry (for example, models that have equipotential surfaces) which cannot be adequately described with the physical part or contact. In this instance, you can create a set of surfaces/edges/vertices which have a coupled degree of freedom by using the Coupling boundary condition. Coupling the degrees of freedom of a set of geometric entity constrains the results calculated for one member of the set to be the same for all members of the set.

Analysis Types Coupling is available for the following analysis types: • Electric Analysis • Steady-State Thermal Analysis Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions • Transient Thermal Analysis • Thermal-Electric Analysis

Common Characteristics The following section outlines the common boundary condition characteristics that include application requirements of the boundary condition, support limitations, as well as loading definitions and values. Dimensional Types • 3D Simulation — Supported. Apply to one or more faces or edges or at least two vertices. • 2D Simulation — Supported. Apply to one or more edges or at least two vertices. Geometry Types: Geometry types supported for the Coupling boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported. Topology: The following topology selection options are supported for Coupling. • Body — Not Supported. • Face — Supported 3D Only. • Edge — Supported. • Vertex — Supported. • Nodes — Not Supported.

Boundary Condition Application To apply a Coupling boundary condition: 1. On the Environment context toolbar: click Conditions>Coupling. Or, right-click the Environment tree object or the Geometry window and select Insert>Coupling. 2. Define the Scoping Method. Restrictions Make sure that you meet the following restrictions when scoping Coupling. • You cannot specify more than one Coupling (the same DOF) on the same geometric entity, such as two edges sharing a common vertex or two faces sharing a common edge. • Coupling should not be applied to a geometric entity that also has a constraint applied to it.

Details View Properties The selections available in the Details view are described below.

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Types of Boundary Conditions Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

DOF Selection — For a Thermal-Electric analysis, select either Temperature or Voltage, otherwise this is a read-only field displaying the DOF selection type. Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

MAPDL References and Notes Coupling is achieved through the use of the CE command.

Constraint Equation This feature allows you to relate the motion of different portions of a model through the use of an equation. The equation relates the degrees of freedom (DOF) of one or more Remote Points for Harmonic, Modal, Modal (SAMCEF), Static Structural, Static Structural (SAMCEF), or Transient Structural systems, or one or more joints for the ANSYS Rigid Dynamics solver. For example, the motion along the X direction of one remote point (Remote Point A) could be made to follow the motion of another remote point (Remote Point B) along the Z direction by: 0 = [1/mm · Remote Point A (X Displacement)] — [1/mm · Remote Point B (Z Displacement)] The equation is a linear combination of the DOF values. Thus, each term in the equation is defined by a coefficient followed by a node (Remote Point) and a degree of freedom label. Summation of the linear combination may be set to a non-zero value. For example: 7 = [4.1/mm · Remote Point A (X Displacement)] + [1/rad · Remote Vertex(Rotation Z)] Similarly, for the ANSYS Rigid Dynamics solver, to make the rotational velocity of gear A (Revolute A) to follow the rotational velocity of gear B (Revolute B), in the Z direction, the following constraint equation should be written: 0 = [1/rad · Revolute A (Omega Z)] — [1/rad · Revolute B (Omega Z)]

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Setting Up Boundary Conditions This equation is a linear combination of the Joints DOF values. Thus, each term in the equation is defined by a coefficient followed by a joint and a degree of freedom label. Summation of the linear combination may be set to a non-zero value. For example: 7 = [4.1/mm · Joint A (X Velocity)] + [1/rad · Joint B (Omega Z)] Note that the Joints DOF can be expressed in terms of velocities or accelerations. However, all terms in the equation will be based on the same nature of degrees of freedom, that is, all velocities or all accelerations. To apply a constraint equation support: 1. Insert a Constraint Equation object by: a. Selecting Constraint Equation from the Conditions drop-down menu. Or… b. Right-clicking on the environment object and selecting Insert> Constraint Equation. 2. In the Details view, enter a constant value that will represent one side of the constraint equation. The default constant value is zero. 3. In the Worksheet, right-click in the first row and choose Add, then enter data to represent the opposite side of the equation. For the first term of the equation, enter a value for the Coefficient, then select entries for Remote Point or Joint and DOF Selection. Add a row and enter similar data for each subsequent term of the equation. The resulting equation displays as you enter the data. Using the example presented above, a constant value of 7 is entered into the Details view, and the data shown in the table is entered in the Worksheet.

Note For Harmonic, Modal, Static Structural, and Transient Structural systems, the first unique degree of freedom in the equation is eliminated in terms of all other degrees of freedom in the equation. A unique degree of freedom is one which is not specified in any other constraint equation, coupled node set, specified displacement set, or master degree of freedom set. You should make the first term of the equation be the degree of freedom to be eliminated. Although you may, in theory, specify the same degree of freedom in more than one equation, you must be careful to avoid over-specification.

Constraint Equation Characteristics • In the Worksheet, you can insert rows, modify an existing row, or delete a row. 818

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Types of Boundary Conditions • A local coordinate system is defined in each remote point that is used. • The constant term is treated as a value with no unit of measure. • Coefficients for X Displacement, Y Displacement, Z Displacement, X Velocity, Y Velocity, Z Velocity, X Acceleration, Y Acceleration, and Z Acceleration have a unit of 1/length. • Coefficients for Rotation X, Rotation Y, Rotation Z, Omega X, Omega Y, Omega Z, Omega Dot X, Omega Dot Y, and Omega Dot Z have a unit of 1/angle. Note that in a velocity based constraint equation, coefficients use angle units and not rotational velocity units. • If you change a DOF such that the unit type of a coefficient also changes (for example, rotation to displacement, or vice versa), then the coefficient resets to 0. • You can parameterize the constant value entered in the Details view. • The state for the Constraint Equation object will be under-defined (? in the tree) under the following circumstances: – There are no rows with valid selections. – Remote Points being used are underdefined or suppressed. – Joints being used are underdefined or suppressed. – The analysis type does not support this feature. – The selected DOFs are invalid for the analysis (2D versus 3D, or remote point versus joints DOFs). • The graphic user interface does not check for overconstraint.

Pipe Idealization Pipe Idealization is a (boundary) condition used to model pipes that have cross-section distortion. This is common for curved pipe structures under loading. It is related to the mesh and acts much like a mesh control. Pipe elements are created by meshing lines or curves.

Prerequisites 1. In the Line Body’s (Geometry Object) Details view Definition category, the Model Type option must be set to Pipe. 2. The scoped line-body must be meshed with higher order elements. This means that Element Midside Nodes option under the Advanced category of the Mesh Object, must be set to Kept. If not, the solver reports an error. 3. Element Midside Nodes in the Advanced section of the Mesh Details panel must be set to Kept); otherwise the solver will report an error.

Extend Elbow Elements You can extend the elbow elements to adjacent edges in order to reduce the boundary effects caused by the incompatible section deformation between edges modeled as straight pipes and high deformation pipes (elbows). If you do not want to extend the elements, under the Extend to Adjacent Elements section of the Details panel set Extend to No. To extend the elements, set Extend to Factor. You can Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions then enter a Factor value, which will extend the elements to the adjacent edge up to a length of factor times selected pipe diameter. If the length calculated by factor times pipe diameter is less than the length of one element, it will still be extended by one element.

Support Limitations Note the following limitations for this condition. • If one or more of the elbow elements has a subtended angle of more than 45 degrees, a warning is reported. The solution can proceed, or you may want to use a finer mesh for better results. • Pipe Idealization cannot be use with symmetry. • Although the solution will account for cross section distortions, the graphics rendering for the results will display the cross sections in their original shape.

Analysis Types Pipe Idealization is available for the following analysis types: • Modal • Harmonic Response • Static Structural • Transient Structural

Common Characteristics The following section outlines the common boundary condition characteristics that include application requirements of the boundary condition, support limitations, as well as loading definitions and values. Dimensional Types • 3D Simulation — Supported — Line Bodies Only. Apply to one or more edges or at least two vertices. • 2D Simulation — Not Supported. Geometry Types: Geometry types supported for the Pipe Idealization boundary condition include: • Solid — Not Supported. • Surface/Shell — Not Supported. • Wire Body/Line Body/Beam — Supported. Topology: The following topology selection options are supported for Pipe Idealization. • Body — Not Supported. • Face — Not Supported. • Edge — Supported. It can only be scoped to edges that have been modeled as pipes. It can be scoped directly to the geometry or to a Named Selection containing edges that are modeled as pipes.

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Types of Boundary Conditions • Vertex — Not Supported. • Nodes — Supported — for node-based Named Selections

Boundary Condition Application To apply a Pipe Idealization: 1. On the Environment context toolbar: click Conditions>Pipe Idealization. Or, right-click the Environment tree object or the Geometry window and select Insert>Pipe Idealization. 2. Verify that in the Details panel for the Mesh object, Element Midside Nodes in the Advanced section is set to Kept. 3. If you choose to Extend to Adjacent Elements, enter a Factor. 4. Define the Scoping Method.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Options include: • Geometry Selection — Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tools. – Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection — Indicates that the geometry selection is defined by a Named Selection. – Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections.

Definition

Suppressed — Include (No — default) or exclude (Yes) the boundary condition. Formulation — Read-only field defined as Curved/Deformed.

Extend to Adjacent Elements

Extend — Do not extend to adjacent elements (No) or specify as Factor (default). Factor

MAPDL References and Notes The following MAPDL commands, element types, and considerations are applicable for this boundary condition. • Pipe element types include PIPE288 (3D two-node pipe) and PIPE289 (3D three-node pipe). Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions • If a pipe idealization is scoped to a pipe, the underneath PIPE289 elements of the pipe are modified to ELBOW290 elements.

Direct FE Type Boundary Conditions The Direct Finite Element (FE) menu contains options that allow you to apply boundary conditions directly to the nodes on the finite element mesh of a model. These boundary conditions are scoped via nodebased Named Selections. They differ from geometry based boundary conditions in the fact that they are applied directly to the nodes during solution calculations whereas geometry-based boundary conditions are applied through special loading elements such as SURF, CONTAC, or FOLLW201 elements. These boundary conditions are applied in the Nodal Coordinate System (except Nodal Pressure). Direct FE boundary conditions cannot be applied to nodes that are already scoped with geometry-based constraints which may modify the Nodal Coordinate system. The boundary conditions contained under the Direct FE heading are listed below. Nodal Orientation Nodal Force Nodal Pressure Nodal Displacement Nodal Rotation EM (Electro-Mechanical) Transducer

Nodal Orientation Nodal Orientation objects are meant to rotate the nodes to a given coordinate system that you select in the GUI. By inserting a Nodal Orientation object and scoping it to a subset of nodes, you can create a Nodal Coordinate System and apply nodal rotations to the scoped nodes. Later, other node based boundary conditions (Nodal Force, Nodal Displacements, and Nodal Rotations) can use these Nodal Coordinate Systems. When two or more Nodal Orientations prescribe different Nodal Coordinate Systems at a single node, the object that is added last (in the tree) is applied.

Analysis Types Nodal Orientation is available for the following analysis types: • Modal • Harmonic Response • Static Structural • Transient Structural

Common Characteristics The following section outlines the common boundary condition characteristics that include application requirements of the boundary condition, support limitations, as well as loading definitions and values. Dimensional Types • 3D Simulation — Supported.

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Types of Boundary Conditions • 2D Simulation — Supported. Geometry Types: Geometry types supported for the Nodal Orientation boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported. Topology: The Nodal Orientation boundary condition is scoped via node-based Named Selections only. See the Specifying Named Selections by Direct Node Selection Help section for more information.

Boundary Condition Application To define Nodal Orientation and apply it to nodes: 1. On the Environment context toolbar, click Direct FE > Nodal Orientation. Or, right-click the Environment tree object or the Geometry window and select Insert>Nodal Orientation. 2. Click the Named Selection drop-down list and then select the node-based Named Selection to prescribe the scope of the boundary conditions. 3. Select the coordinate system that you want to use to define nodal orientation.

Details View Properties The Details View selections are described below. Category

Fields/Options/Description

Scope

Scoping Method — Read-only field that displays scoping method – Named Selection. Named Selection — Drop-down list of available node-based Named Selections. Coordinate System — Drop-down list of available coordinate systems. The selected system is used to orientate the nodes in the Named Selection.

Definition

Suppressed — Includes or excludes the boundary condition in the analysis.

Nodal Force Using Nodal Force, you can apply a force to an individual node or a set of nodes. You must create a node based Named Selection before you can apply a Nodal Force. The Nodal Force that you apply in Mechanical is represented as an F Command in the Mechanical APDL application. You can also apply a spatially varying Nodal Force to the scoped nodes.

Note A Nodal Force may be added during Solution Restart without losing the restart points.

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Setting Up Boundary Conditions

Analysis Types Nodal Force is available for the following analysis types: • Harmonic Response • Static Structural • Transient Structural

Common Characteristics The following section outlines the common boundary condition characteristics that include application requirements of the boundary condition, support limitations, as well as loading definitions and values. Dimensional Types • 3D Simulation — Supported. • 2D Simulation — Supported. Geometry Types: Geometry types supported for the Nodal Force boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported. Topology: The Nodal Force boundary condition is scoped via node-based Named Selections only. See the Specifying Named Selections by Direct Node Selection Help section for more information.

Boundary Condition Application To apply a Nodal Force: 1. On the Environment toolbar, click Direct FE > Nodal Force. Or, right-click the Environment tree object or the Geometry window and select Insert>Nodal Force. 2. Click the Named Selection drop-down list and then select the node-based Named Section to prescribe the scope of the Nodal Force. 3. Enter a magnitude for the X, Y, and Z component to define the load.

Tip Define a Nodal Orientation for the Named Selection to control the Nodal Coordinate System.

Details View Properties The Details View selections are described below.

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Types of Boundary Conditions Category

Fields/Options/Description

Scope

Scoping Method — Read-only field that displays scoping method — Named Selection. Named Selection — Drop-down list of available node-based Named Selection.

Definition

Type — Read-only field that describes the node-based object — Force. Coordinate System — Read-only field that displays the coordinate system Nodal Coordinate System. The Nodal Coordinate System can be modified by applying Nodal Orientation objects. X Component — Defines force in the X direction Y Component- Defines force in the Y direction Z Component — Defines force in the Z direction Divide Load by Nodes — Options include: Yes — (Default) Load value is normalized: it is divided by number of scoped nodes before application. No — Load value applied directly to every scoped node. Suppressed — Includes or excludes the boundary condition in the analysis.

Note • When Divide Load by Nodes is set to Yes, the forces are evenly distributed across the nodes and do not result in a constant traction. • Two Nodal Force objects that have same scoping do not produce a cumulative loading effect. The Nodal Force that was specified last takes priority and is applied, and as a result, the other Nodal Force is ignored. • A load applied to a geometric entity and a Nodal Force produce a resultant effect.

Nodal Pressure Using Nodal Pressure, you can apply pressure on element faces. You must create a node based named selection before you can apply a Nodal Pressure. It is applicable for solid and surface bodies only. Specifically, an elemental face pressure is created only if all of the nodes of a given element face (including midside) are included. If all nodes defining a face are shared by an adjacent face of another selected element, the face is not free and will not have a load applied.

Warning For application to surface bodies, the MAPDL solver logic for this load is such that if all of the nodes of a shell element are specified, then the load is applied to the whole element face. However, if only some nodes are specified on an element and those nodes constitute a complete external edge, then an edge pressure is created. Therefore, it is critical that you Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions make sure that you have not selected nodes that constitute only a free shell edge. This is because shell edge pressures are input on a per-unit-length basis, and Mechanical treats this load always as a per-unit-area quantity. See the SHELL181 Element Description for more information. Nodal Pressures applied to shell bodies act in the opposite direction of geometry-based pressures.

Note A Nodal Pressure may be added during Solution Restart without losing the restart points.

Analysis Types Nodal Pressure is available for the following analysis types: • Harmonic Response (Full) Analysis Using Pre-Stressed Structural System • Static Structural • Transient Structural

Common Characteristics The following section outlines the common boundary condition characteristics that include application requirements of the boundary condition, support limitations, as well as loading definitions and values. Dimensional Types • 3D Simulation — Supported. • 2D Simulation — Supported. Geometry Types: Geometry types supported for the Nodal Pressure boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported. Topology: The Nodal Pressure boundary condition is scoped via node-based Named Selections only. See the Specifying Named Selections by Direct Node Selection Help section for more information.

Boundary Condition Application To apply a Nodal Pressure: 1. On the Environment toolbar, click Direct FE > Nodal Pressure. Or, right-click the Environment tree object or the Geometry window and select Insert>Nodal Pressure. 2. Click the Named Selection drop-down list, and then select the node-based Named Selection to prescribe the scope of the Nodal Pressure.

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Types of Boundary Conditions 3. Enter a magnitude for the load.

Details View Properties The Details View selections are described below. Category

Fields/Options/Description

Scope

Scoping Method — Read-only field that displays scoping method — Named Selection. Named Selection — Drop-down list of available node-based Named Selections.

Definition

Type — Read-only field that displays boundary condition type — Pressure. Define By — Read-only field that displays that the boundary condition is acting Normal To the surface to which it is attached. Magnitude — Input field to define the magnitude of the boundary condition. This value can be defined as a Constant, in Tabular form, or as a Function. Suppressed — Includes or excludes the boundary condition in the analysis.

Note • To apply Nodal Pressure, the Named Selections that you create must include nodes such that they define an element face. • Two Nodal Pressure objects that have same scoping do not produce a cumulative loading effect. The Nodal Pressure that was specified last takes priority and is applied, and as a result, the other Nodal Pressure is ignored. • A load applied to a geometric entity and a Nodal Pressure produce a resultant effect. • You can apply a spatially varying Nodal Pressure to scoped nodes.

MAPDL References and Notes For more information on the solver representation of this load, reference the SF command in the Mechanical APDL Command Reference.

Nodal Displacement Using Nodal Displacement, you can apply a displacement to an individual node or a set of nodes. You must create a node based named selection before you can apply a Nodal Displacement. You can also apply a spatially varying Nodal Displacement to the scoped nodes.

Analysis Types Nodal Displacement is available for the following analysis types:

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Setting Up Boundary Conditions • Modal • Harmonic Response • Static Structural • Transient Structural

Common Characteristics The following section outlines the common boundary condition characteristics that include application requirements of the boundary condition, support limitations, as well as loading definitions and values. Dimensional Types • 3D Simulation — Supported. • 2D Simulation — Supported. Geometry Types: Geometry types supported for the Nodal Displacement boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported. Topology: The Nodal Displacement boundary condition is scoped via node-based Named Selections only. See the Specifying Named Selections by Direct Node Selection Help section for more information.

Boundary Condition Application To apply a Nodal Displacement: 1.

On the Environment toolbar, click Direct FE>Nodal Displacement. Or, right-click the Environment tree object or the Geometry window and select Insert>Nodal Displacement.

2.

Click the Named Selection drop-down list and then select the node-based Named Section to prescribe the scope of the Nodal Displacement.

3.

Define loads in the X, Y, and/or Z directions.

Tip Define a Nodal Orientation for the Named Selection to control the Nodal Coordinate System.

Details View Properties The Details View selections are described below. Category

Fields/Options/Description

Scope

Scoping Method — Read-only field that displays scoping method — Named Selection.

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Fields/Options/Description Named Selection — Drop-down list of available node-based Named Selections.

Definition

Type — Read-only field that displays boundary condition type — Displacement. Coordinate System — Read-only field that displays the coordinate system — Nodal Coordinate System. X Component — Specifies a displacement value in the X direction. The default value is Free (no Displacement constraint applied). This value can also be defined as a Constant, in Tabular form, or as a Function. Y Component — Specifies a displacement value in the Y direction. The default value is Free (no Displacement constraint applied). This value can also be defined as a Constant, in Tabular form, or as a Function. Z Component — Specifies a displacement value in the Z direction. The default value is Free (no Displacement constraint applied). This value can also be defined as a Constant, in Tabular form, or as a Function. Suppressed — Includes or excludes the boundary condition in the analysis.

Note • Solution Restarts are only supported for Tabular data modifications. • If a Component is set to Function, all other Components automatically default to the Free setting and become read-only. • Two Nodal Displacement objects that have same scoping do not produce a cumulative loading effect. The Nodal Displacement that was specified last takes priority and is applied, and as a result, the other Nodal Displacement is ignored.

Nodal Rotation Using Nodal Rotation, you can apply a fixed rotation to an individual node or a set of nodes that have rotational degrees of freedom (DOFs).

Analysis Types Nodal Rotation is available for the following analysis types: • Modal • Harmonic Response • Static Structural • Transient Structural

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Setting Up Boundary Conditions

Common Characteristics The following section outlines the common boundary condition characteristics that include application requirements of the boundary condition, support limitations, as well as loading definitions and values. Dimensional Types • 3D Simulation — Supported. • 2D Simulation — Supported. Geometry Types: Geometry types supported for the Nodal Rotation boundary condition include: • Solid — Not Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Supported. Topology: The Nodal Rotation boundary condition is scoped via node-based Named Selections only. See the Specifying Named Selections by Direct Node Selection Help section for more information.

Boundary Condition Application To apply a Nodal Rotation: 1.

On the Environment toolbar, click Direct FE>Nodal Rotation. Or, right-click the Environment tree object or the Geometry window and select Insert>Nodal Rotation.

2.

Click the Named Selection drop-down list and then select the node-based Named Section to prescribe the scope of the Nodal Rotation.

3.

Define the X, Y, and/or Z axis as Fixed or Free. At least one Component must be defined as Fixed.

Tip Define a Nodal Orientation for the Named Selection to control the Nodal Coordinate System.

Details View Properties The Details View selections are described below. Category

Fields/Options/Description

Scope

Scoping Method — Read-only field that displays scoping method — Named Selection. Named Selection — Drop-down list of available node-based Named Selections.

Definition

Type — Read-only field that displays boundary condition type — Fixed Rotation. Coordinate System — Read-only field that displays the coordinate system — Nodal Coordinate System.

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Types of Boundary Conditions Category

Fields/Options/Description X Component — Define the x-axis of rotation as Fixed (default) or Free. Y Component — Define the y-axis of rotation as Fixed (default) or Free. Z Component — Define the z-axis of rotation as Fixed (default) or Free. Suppressed — Includes or excludes the boundary condition in the analysis.

Note When parameterizing this boundary condition, a Free axis of rotation is represented by a zero (0) and Fixed with a value of one (1) inside the Parameter tab in ANSYS Workbench (outside of Mechanical).

EM (Electro-Mechanical) Transducer Using the EM Transducer boundary condition, you can model simple Micro-Electro-Mechanical Systems (MEMS) devices.

Analysis Types EM Transducer is available for the following analysis types: • Static Structural • Transient Structural

Common Characteristics The following section outlines the common boundary condition characteristics that include application requirements of the boundary condition, support limitations, as well as loading definitions and values. Dimensional Types • 3D Simulation — Supported. Node-based Named Selections only support face node selection. • 2D Simulation — Supported. Node-based Named Selection only support edge node selection. Geometry Types: Geometry types supported for the EM Transducer boundary condition include: • Solid — Supported. • Surface/Shell — Supported. • Wire Body/Line Body/Beam — Not Supported. Topology: The EM Transducer boundary condition is scoped via node-based Named Selections only. See the Specifying Named Selections by Direct Node Selection Help section for more information. Loading Types: The loading for this boundary condition is always defined as a Voltage Difference. Loading Data Definition: Enter loading data using one of the following options. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions • Constant. Supported. This value can be Parameterized. • Tabular (Time Varying). Supported. This value cannot be Parameterized. • Tabular (Spatially Varying). Not Supported. • Function (Time Varying). Supported. This value cannot be Parameterized. • Function (Spatially Varying). Not Supported.

Boundary Condition Application To apply EM Transducer: 1.

On the Environment toolbar, click Direct FE>EM Transducer. Or, right-click the Environment tree object or the Geometry window and select Insert>EM Transducer.

2.

Enter a Voltage Difference value.

3.

Specify a GAP Direction, either X, Y, or Z based on the default Nodal Coordinate System or a userdefined nodal coordinate system.

4.

Enter Initial Gap and Minimal Gap values.

Details View Properties The selections available in the Details view are described below. Category

Fields/Options/Description

Scope

Scoping Method — Read-only field that displays scoping method — Named Selection. Named Selection — Drop-down list of available node-based Named Selections.

Definition

Type — Read-only field that describes the node-based object — EM Transducer. Voltage Difference — Input field for Voltage value. Suppressed — Include (No — default) or exclude (Yes) the boundary condition.

Voltage Surface Location

Coordinate System Read-only field that displays the coordinate system — Nodal Coordinate System. GAP Direction Specify the structural DOF used, X, Y, or Z based on the Nodal Coordinate System. This is used with the Volt DOF. Initial Gap Input field for initial range of motion (in GAP Direction). Can be Parameterized. Minimal Gap Input field for minimal range of motion (in GAP Direction). Can be Parameterized.

Function[1]

Unit System Read-only field displaying the unit of measure associated with the Voltage. Angular Measure Read-only field displaying the unit of measure for the voltage’s angle.

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Types of Boundary Conditions Category

Fields/Options/Description

Graph Controls[1]

Number of Segments The function is graphed with a default value of 200 line segments. You can change this value to better visualize the function.

1. This category displays only when Voltage Difference is specified as a Function.

MAPDL References and Notes This boundary condition uses the EMTGEN command to generate a set of TRANS126 elements between the surface nodes of a moveable structure and a plane of nodes, typically representing a ground plane.

Note The newly created (by EMTGEN command) ground plane nodes (of TRANS126 elements) are assumed to be fixed.

Remote Boundary Conditions The boundary conditions listed here can make use of the Remote Point feature (object) provided by Mechanical. The Remote Point associated with one of the given objects is either created and defined by you (you create a Remote Point object that the remote boundary condition references) or it is automatically generated by the system (you can think of it as an “internal” remote point — no Remote Point object exists in the object tree). When defined with a remote point, these objects are considered remote boundary conditions. The remote point gives the object an “abstract” quality because it is not directly applied to the nodes or vertices of a model. However, you can directly scope a single node or vertex of your model to some of the boundary conditions listed below; specifically Point Masses, Springs, and Joints. Using the Details view property, Applied By, for these objects you can switch between the settings Remote Attachment and Direct Attachment. When directly applied, they are not considered remote boundary conditions and as a result do not provide certain properties, such as Pinball or Formulation. • Point Mass • Thermal Point Mass • Joints • Spring • Bearing • Beam Connection • Remote Displacement • Remote Force • Moment Remote boundary conditions have the following characteristics: Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions • All remote boundary conditions make use of MPC contact used in the Mechanical APDL application. See the Geometry Behaviors and Support Specifications section in the Mechanical Help as well as the SurfaceBased Constraints section in the Contact Technology Guide — part of the Mechanical APDL Help, for more information. • You are advised to check reaction forces to ensure that a remote boundary condition has been fully applied, especially if the boundary condition shares geometry with other remote boundary conditions, any type of constraint, or even MPC contact. • Once a remote boundary condition is created, you can generate an external Remote Point based on the scoping of the remote boundary condition using the Promote Remote Point feature (RMB menu). Annotations are available for point masses, springs, beam connections, and bearings. You can toggle the visibility of these annotations in the Annotation Preferences dialog box. For more information, see Specifying Annotation Preferences (p. 119).

Imported Boundary Conditions Using this feature, you can directly apply results from one analysis as loads for a structural, thermal, electric, thermal-electric, or harmonic response analysis with data transfer.

Note • You can import data from external files and apply it in a Mechanical application analysis by creating a link with an upstream External Data system; see External Data Import. • You can use System Coupling to apply loads from a Fluent CFD analysis; see System Coupling. • You can use the HFSS, Maxwell, or Q3D Extractor applications and perform an analysis in Mechanical by applying the imported loads.

Imported Loads Imported boundary conditions include: Imported Body Force Density Imported Body Temperature Imported Convection Coefficient Imported Displacement Imported Force Imported Heat Flux Imported Heat Generation Imported Initial Strain Imported Initial Stress Imported Pressure Imported Remote Loads Imported Surface Force Density Imported Temperature Imported Velocity

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Types of Boundary Conditions

Analysis Type Support The following table shows valid environment interaction to import loads for an analysis with data transfer. Source Analysis/System (Transfer Data Type)

Target Analysis

CFD (Convection)

Steady State Thermal, Transient Thermal, Thermal — Electric

CFD (Pressure)

Static Structural, Transient Structural1 (p. 835)

CFD (Temperature)

Steady State Thermal, Transient Thermal, Thermal — Electric, Static Structural, Transient Structural1 (p. 835)

System Coupling (Heat Flow, Convection, Temperature)

Steady State Thermal

Electric (Joule Heat)

Steady State Thermal, Transient Thermal

Electromagnetic (Force Density)

Static Structural, Transient Structural1 (p. 835)

Electromagnetic (Power Loss Density)

Steady State Thermal, Transient Thermal

Electromagnetic (Force and Moment)

Harmonic Response2 (p. 835)

External Files (Displacement, Force, Temperature, Stress, Strain, Body Force Density)

Static Structural, Transient Structural1 (p. 835)

External Files (Temperature, Convection, Heat Flux, Heat Generation)

Steady State Thermal, Transient Thermal, Thermal – Electric

External Files (Pressure)

Static Structural, Transient Structural1 (p. 835), Harmonic Response

External Files (Velocity)

Acoustic Analysis3 (p. 835)

Harmonic Response (Velocity)

Acoustic Analysis3 (p. 835)

Polyflow (Temperature)

Steady State Thermal, Transient Thermal, Thermal — Electric, Static Structural, Transient Structural1 (p. 835)

Static Structural, Transient Structural (Displacement, Temperature)

Static Structural, Transient Structural1 (p. 835)

Steady-State Thermal, Transient Thermal (Temperature)

Static Structural, Transient Structural1 (p. 835), Electric

Thermal-Electric (Temperature)

Static Structural, Transient Structural1 (p. 835)

1 — Rigid dynamics solver is not supported. 2 — see the Importing Data into a Harmonic Analysis section for the specific steps to perform the analysis. 3 — An acoustic analysis is performed via ACT. For information on creating optimization extensions, see the Application Customization Toolkit Developer’s Guide and the Application Customization Toolkit Reference Guide. These documents are part of the ANSYS Customization Suite on the ANSYS Customer Portal. You can work with imported loads only when you perform an analysis with data transfer. To import loads for an analysis: 1.

In the Project Schematic, add an appropriate analysis with data transfer to create a link between the solution of a previous analysis and the newly added analysis. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions 2.

Attach geometry to the analysis system, and then double-click Setup to open the Mechanical window. An Imported Load folder is added under the environment folder, by default.

3.

To add an imported load, click the Imported Load folder to make the Environment toolbar available or right mouse click on the Imported Load folder and select the appropriate load from the context menu.

Note An Imported Load can also be created from duplicating an existing imported load. Perform a right mouse click on an Imported Load to display the context menu, select duplicate to add an identical Imported Load to your model.

4.

On the Environment toolbar, click Imported Loads, and then select an appropriate load.

5.

Select the appropriate geometry, using the geometry selection or geometry-based Named Selection option and then click Apply. The following Imported Loads can also be scoped to node-based Named Selections. • Imported Body Temperatures (from External Data, for Submodeling2 (p. 838), or for Thermal-Stress) • Imported Displacements (from External Data or for Submodeling) • Imported Forces (from External Data) • Imported Temperatures (from External Data or for Submodeling) • Imported Velocities (from External Data) • Imported Initial Stress and Imported Initial Strain (from External Data), when Applied To is set to Corner Nodes

6.

Set the appropriate options in the Details view.

7.

The Data View can be used to control the load data that is imported. Each data transfer incorporates some or all of the column types shown below.

• Source Time/Frequency — Time at which the load will be imported. • Source Time Step — Time Step at which the load will be imported. • Analysis Time/Frequency — Time at which the load will be applied when the analysis is solved.

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Types of Boundary Conditions • Scale — The amount by which the imported load values are scaled before they are sent to the solver. The scale value is applied to the imported load values in the solver unit system. For Imported Temperature and Imported Body Temperature loads: – The values used in the solution are calculated by first converting the imported load values into the solver unit system and then multiplying the scale value. • Offset — An offset that is added to the imported load values before they are sent to the solver. The offset value is applied to the imported load values in the solver unit system. Specific transfer details can be found in the Special Analysis Topics (p. 301) section. 8.

If you are using the ANSYS solver, loads can be applied using tables, or can be applied at each analysis time/frequency specified in the imported load using the Tabular Loading property. When sending as tables, the loads can either be ramped or step changed (stepped) between the specified Analysis Times/Frequencies. a.

When ramped, the load value at step/sub-step is calculated using linear interpolation in the range where solve step/sub-step falls.

b.

When stepped, the load value specified at t2 is applied in the range (t1, t2], where (t1, t2] is the range greater than t1 and less than or equal to t2.

Note • When program controlled, the loads are sent as tables when Analysis Time(s)/Frequency(ies) not matching any step end times/maximum frequency are present in the load definition. The loads are ramped for static/steady state and harmonic analyses and step applied for transient analyses. • The loads are always sent as tables when Ramped or Stepped is chosen. • Extrapolation is not performed when stepping/ramping the loads. If the solve time for a step/sub-step falls outside the specified Analysis Time/Frequency, then the load value at the nearest specified analysis time is used. • For temperature loads, the values are ramped from reference temperature for the first time step. For all other loads, the values are ramped from zero. • User can choose not to send the loads as tables using the Off option. The analysis times/frequencies specified in the load definition must match the step end times/maximum frequency in this case for the solution to succeed.

9.

In the Project tree, right-click the imported load, and then click Import Load to import the load.

10. When the load has been imported successfully, a contour or vector plot will be displayed in the Geometry window. • For vector loads types, contours plots of the magnitude (Total) or X/Y/Z component can be viewed by changing the Data option in the details pane. Defaults to a vector plot (All).

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Setting Up Boundary Conditions • For tensor loads types, contours plots of Equivalent (von-Mises) or XX/YY/ZZ/XY/YZ/ZX component can be viewed by changing the Data option in the details pane. Defaults to a Vector Principal plot (All). • For Imported Convection loads, contours plots of film coefficient or ambient temperature can be viewed by changing the Data option in the details pane. • For complex load types, e.g. Pressure/Velocity in Harmonic Response, the Real/Imaginary component of the data can be viewed by changing the Complex Data Component option in the details pane. • The Legend controls options allow the user to control the range of data displayed in the graphics window. By default, it is set to Program control, which allows for complete data to be displayed. If you are interested in a particular range of data, you can select the Manual option, and then set the minimum/maximum for the range.

Note • The isoline option is drawn based on nodal values. When drawing isolines for imported loads that store element values (Imported Body Force Density, Imported Convection, Imported Heat Generation, Imported Heat Flux, Imported Pressure, Imported Surface Force Density, Imported Initial Stress and Imported Initial Strain), the program automatically calculates nodal values by averaging values of the elements to which a node is attached. • The minimum and maximum values of source data are also available in Legend Controls for External Data Import, Thermal-Stress, Submodeling, and Acoustic Coupling analyses.

11. To preview the imported load contour that applies to a given row in the Data View, use the Active Row option in the Details view. 12. To activate or deactivate the load at a step, highlight the specific step in the Graph or Tabular Data window, and choose Activate/Deactivate at this step! See Activation/Deactivation of Loads for additional rules when multiple load objects of the same type exist on common geometry selections. To export data, select the Imported Load object, right-click the mouse, and then select Export. Additional information on Thermal-Stress, Fluid-Structure Interaction (FSI), Ansoft — Mechanical Data Transfer, Icepak to Mechanical Data Transfer, Submodeling, and External Data Import can be found in the Special Analysis Topics (p. 301) section.

Note • Convergence is not supported for environments with imported loads.

2 — Not supported for Shell-Shell submodeling.

Imported Body Force Density When electromagnetic body forces are transferred to a structural environment, an Imported Body Force Density object can be inserted to represent the transfer.

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Types of Boundary Conditions See the Imported Boundary Conditions (p. 834) section for applicable transfers or for specific steps to transfer data.

Note For a particular load step, an active Imported Body Force Density load will overwrite other Imported Body Force Density loads that exist higher (previously added) in the tree, on common geometry selections. See Activation/Deactivation of Loads (p. 637) for additional rules when multiple load objects of the same type exist on common geometry selections.

Note For large-deflection analyses, the loads are applied to the initial size of the element, not the current size.

Imported Body Temperature When temperatures are transferred to a structural or electric analysis, an Imported Body Temperature object is automatically inserted to represent the transfer. If the load is applied to one or more surface bodies, the Shell Face option in the details view enables you to apply the temperatures to Both faces, to the Top face(s) only, or to the Bottom face(s) only. By default, the temperatures are applied to both the top and bottom faces of the selection. See the Imported Boundary Conditions (p. 834) section for applicable transfers or for specific steps to transfer data.

Note • Adaptive Convergence objects inserted under an environment that is referenced by an Imported Body Temperature object will invalidate the Imported Body Temperature object, and not allow a solution to progress. • For a particular load step, an active Imported Body Temperature load will overwrite any Thermal Condition loads on common geometry selections. • When a Thermal Condition is specified on the Top or Bottom shell face of a surface body, the opposite face defaults to the environment temperature unless it is otherwise specified from another load object. • For an assembly of bodies with different topologies, you must define a separate Imported Body Temperature load for surface bodies. • The values used in the solution are calculated by first converting the imported load values into the solver unit system and then multiplying the scale value. • For each load step, if an Imported Body Temperature load and a Thermal Condition load are applied on common geometry or node selections, the Imported Body Temperature load takes precedence. An active Imported Body Temperature load will also overwrite other Imported Body Temperature loads that exist higher (previously added) in the tree, on common geo-

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Setting Up Boundary Conditions metry or node selections. See Activation/Deactivation of Loads (p. 637) for additional rules when multiple load objects of the same type exist on common geometry selections. • If a scale factor is specified, the values used in the solution are calculated by first converting the imported load values into the solver unit system and then multiplying the scale value. • For surface bodies, the thickness of each target node is ignored when data is mapped. When importing data from an External Data system, the Shell Thickness Factor property enables you to account for the thickness at each target node, and consequently modify the location used for each target node during the mapping process. See External Data Import for additional information.

Imported Convection Coefficient When CFD convection coefficients are transferred to a thermal analysis, an Imported Convection Coefficient object can be inserted to represent the transfer.

Note A warning message will appear if negative mapped HTC values are present. Insert a validation object and use the Source Value option to determine source nodes with values less than zero. See the Imported Boundary Conditions (p. 834) section for applicable transfers or for specific steps to transfer data.

Imported Displacement When displacements are transferred to a structural analysis, an Imported Displacement object can be inserted to represent the transfer. See the Imported Boundary Conditions (p. 834) section for applicable transfers or for specific steps to transfer data.

Note If one or more nodes with imported displacements have nodal rotations specified on them, Mechanical attempts to negotiate and apply the imported displacements. The imported displacements are transformed to the nodal coordinate system and then applied on the node(s). However, there may be cases when a suitable transformation cannot be obtained (for example, [x,y,z] -> [fixed, free, free] in the global coordinate system becomes [fixed, fixed, free] in the nodal coordinate system if the coordinate system is rotated about the z-axis). For such situations, Mechanical will report a conflict.

Note For each load step, if an Imported Displacement and other support or displacement constraints are applied on common geometry or node selections, you can choose to override the specified constraints by using the Override Constraints property in the details of the Imported Dis-

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Types of Boundary Conditions placement object. By default, the specified constraints are respected and Imported Displacement is applied only to the free degrees of freedom of a node.

Imported Force When forces are transferred to a structural analysis, an Imported Force object can be inserted to represent the transfer. If the import process involves mapping data across meshes, additional result information is reported in the Transfer Summary. The reported source and target force results may be used to validate the mapping and also to appropriately apply a scaling factor. See the Imported Boundary Conditions (p. 834) section for applicable transfers or External Data Import for specific steps to transfer data.

Note Profile preserving algorithms are used to import force loads, therefore the total force on the source and target may not match. Use the scaling factor reported in the Transfer Summary to appropriately scale the load.

Imported Heat Flux When thermal heat is transferred to a thermal environment, an Imported Heat Flux object can be inserted to represent the transfer. See the Imported Boundary Conditions (p. 834) section for applicable transfers or for specific steps to transfer data.

Note For surface bodies, the thickness of each target node is ignored when data is mapped. When importing data from an External Data system, the Shell Thickness Factor property enables you to account for the thickness at each target node, and consequently modify the location used for each target node during the mapping process. See External Data Import for additional information.

Imported Heat Generation When thermal heat is transferred to a thermal environment, an Imported Heat Generation object can be inserted to represent the transfer. Imported Heat Generation applies Joule heating from an electric analysis in a thermal analysis.

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Setting Up Boundary Conditions See the Imported Boundary Conditions (p. 834) section for applicable transfers or for specific steps to transfer data.

Note • The Joule heating, from an Electric analysis, resulting from limited contact electric conductance is ignored during this data transfer. • For each load step, if an Imported Heat Generation load and an Internal Heat Generation load are applied on common geometry selections, the Imported Heat Generation load takes precedence. An active Imported Heat Generation load will also overwrite other Imported Heat Generation loads that exist higher (previously added) in the tree, on common geometry selections. See Activation/Deactivation of Loads (p. 637) for additional rules when multiple load objects of the same type exist on common geometry selections. • For surface bodies, the thickness of each target node is ignored when data is mapped. When importing data from an External Data system, the Shell Thickness Factor property enables you to account for the thickness at each target node, and consequently modify the location used for each target node during the mapping process. See External Data Import for additional information.

Imported Initial Strain When strains are transferred to define the state of a structure at the beginning of a structural analysis, an Imported Initial Strain object can be inserted to represent the transfer. The following supported strain types can be chosen using Sub Type property in the details of the Imported Initial Strain object : • Elastic Strain • Plastic Strain • Equivalent Plastic Strain You can import values for all six components of the symmetric strain tensor (XX, YY, ZZ, XY, YZ and ZX). See External Data Import for additional information. Imported initial strain from External Data can be mapped and applied either to the centroids or corner nodes of the selected bodies using the Applied To property in the Details view. • When Applied To property is set to Corner Nodes, the imported initial strain can also be scoped to Nodal Named Selections. See the Imported Boundary Conditions (p. 834) section for applicable transfers or for specific steps to transfer data.

Note • Imported Initial Strain can only be applied at the start of the first step. Activation/Deactivation of loads is not available for Imported Strain load.

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Types of Boundary Conditions • Imported elastic strain values are not supported for bodies which have the following material types assigned : – Materials with kinematic hardening properties – Gasket materials – Hyperelastic materials • Imported plastic strain values are not supported for bodies which have the following material types assigned : – Porous media – Rate-dependent plasticity – Viscoplasticity • For shell bodies, the user has the option to import strain on All, Top, Middle, or Bottom shell face(s). • For shells with layered sections, All is the only supported option for importing strain on shell faces. • Initial strain can only be applied to a shell body with a default coordinate system. If a coordinate system is specified either directly through the Coordinate System property on the body or indirectly through the Coordinate System property on Layered Section, then the object becomes invalid and strain cannot be imported.

Important Mechanical maps every individual tensor by direct interpolation of individual components. This is numerically the simplest method but is physically inconsistent especially in nonlinear solid mechanics applications. See the Recommendations and Guidelines for Mapping of Initial Stress and Strain Data section for more information.

Imported Initial Stress When stresses are transferred to define the state of a structure at the beginning of a structural analysis, an Imported Initial Stress object can be inserted to represent the transfer. You can import values for all six components of the symmetric stress tensor (XX, YY, ZZ, XY, YZ and ZX). See External Data Import for additional information. Imported initial stress from External Data can be mapped and applied either to the centroids or corner nodes of the selected bodies using the Applied To property in the Details view. • When Applied To property is set to Corner Nodes, the imported initial stress can also be scoped to Nodal Named Selections.

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Setting Up Boundary Conditions See the Imported Boundary Conditions (p. 834) section for applicable transfers or for specific steps to transfer data.

Note • Imported Initial Stress can only be applied at the start of the first step. Activation/Deactivation of loads is not available for Imported Initial Stress load. • Imported Initial Stress load is not supported for bodies which have the following material types assigned : – Materials with kinematic hardening properties – Gasket materials • For shell bodies, the user has the option to import stress on All, Top, Middle, or Bottom shell face(s). • For shells with layered sections specified, All is the only supported option for importing stress on shell faces. • Initial stress can only be applied to a shell body with a default coordinate system. If a coordinate system is specified either directly through the Coordinate System property on the body or indirectly through the Coordinate System property on Layered Section, then the object becomes invalid and stress cannot be imported.

Important Mechanical maps every individual tensor by direct interpolation of individual components. This is numerically the simplest method but is physically inconsistent especially in nonlinear solid mechanics applications. See the Recommendations and Guidelines for Mapping of Initial Stress and Strain Data section for more information.

Recommendations and Guidelines for Mapping of Initial Stress and Strain Data Mechanical maps initial stress and strain data by direct interpolation of individual components. This is numerically the simplest method but is physically inconsistent especially in nonlinear solid mechanics applications. Tensor fields associated with solid mechanics applications – e.g. stress, strains, plastic strains etc. are not independent of each other. The strains are related to the displacements through the compatibility equations and the stresses are related to strains through the constitutive equations. In addition, for plasticity, other equations like the flow rule also relate the plastic strain tensors to the stress tensors. Hence independent interpolation of these tensors will violate these equations which in turn will create a globally un-equilibrated state of stress in the mapped domain. So, using these mapped quantities in nonlinear solid mechanics applications is not recommended. However, irrespective of these limitations, if the user wants to use these mapped fields, it is strongly recommended that he uses a dummy load step in the solver with the imported initial stress/strain results and only apply new loads and/or boundary conditions if and only if the dummy load step converges and the resulting deformation is physically consistent with the problem. Generally, the analysis with the dummy load step will not converge

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Types of Boundary Conditions with loads generated via incorrectly mapped stress/strain fields. Even with a chance convergence in the dummy load step, no guarantee can be given with respect to the correctness of the results. Mechanical provides an option to view contours of equivalent (von-Mises) stress/strain, as well as individual components (XX, YY, ZZ, XY, YZ and ZX) using Data option in details pane of Imported Initial Stress/Strain. User can insert a Mapping Validation object under the Imported Load, perform Source Value validation, and turn Display In Parent, On, to view overlapping contours of interpolated data with source data and compare the equivalent stress/strain from the interpolated data with the source data. The equivalent stress and strain are calculated using the von Mises equation: Figure 31: Equivalent (von-Mises) stress

 =

− 



+

− 



+

− 

+

    +  + 

Figure 32: Equivalent (von-Mises) strain (elastic/plastic/equivalent plastic)

 =

 − 



+  −



+  −  +

  +   +  

Imported Pressure When pressures are transferred to a structural or harmonic analysis, an Imported Pressure object can be inserted to represent the transfer. See the Imported Boundary Conditions (p. 834) section for applicable transfers or for specific steps to transfer data.

Note For surface bodies, the thickness of each target node is ignored when data is mapped. When importing data from an External Data system, the Shell Thickness Factor property enables you to account for the thickness at each target node, and consequently modify the location used for each target node during the mapping process. See External Data Import for additional information. Imported pressure loads from External Data can be mapped and applied either to the centroids or corner nodes of the selected element faces 3D or element edges(2D) using the Applied to property in the Details view. When imported pressure loads are applied to corner nodes, the Filter property under the Scope group allows the user to select a subset of the scoped element faces/edges and imports the load only on the specified subset. To filter a subset of element faces/edges, follow the following steps: 1. Create a nodal Named Selection to select all the nodes in the region of interest. 2. Select the created named selection in the Filter property. You may also choose any pre-existing nodal Named Selection. The filtered subset of element edges/faces is then determined by the following: Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Setting Up Boundary Conditions 1. The element faces/edges which have all their corner nodes defined in the filter will be included in the mapping 2. For the element edges/faces whose corner nodes are only partially defined the filter, i.e. the faces/edges which have some corner nodes included in the filter, but not all the Include Partial Faces/Edges property can be used to include or exclude the element faces/edges from the scoping.

Imported Remote Loads When electromagnetic forces and moments are transferred to a harmonic environment, an Imported Remote Loads object is inserted into the environment to represent the transfer. See the Importing Data into a Harmonic Analysis section for the specific steps to transfer data.

Imported Surface Force Density When electromagnetic surface forces are transferred to a structural environment, an Imported Surface Force Density object can be inserted to represent the transfer. See the Imported Boundary Conditions (p. 834) section for applicable transfers or for specific steps to transfer data.

Imported Temperature When temperatures are transferred to a thermal analysis, an Imported Temperature object can be inserted to represent the transfer.

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Spatial Varying Loads and Displacements See the Imported Boundary Conditions (p. 834) section for applicable transfers or for specific steps to transfer data.

Note • For each load step, if an Imported Temperature load and Temperature load are applied on common geometry or node selections, the Imported Temperature load takes precedence. An active Imported Temperature load will also overwrite other Imported Temperature loads that exist higher (previously added) in the tree, on common geometry or node selections. See Activation/Deactivation of Loads (p. 637) for additional rules when multiple load objects of the same type exist on common geometry selections. • If a scale factor is specified, the values used in the solution are calculated by first converting the imported load values into the solver unit system and then multiplying the scale value. • For surface bodies, the thickness of each target node is ignored when data is mapped. When importing data from an External Data system, the Shell Thickness Factor property enables you to account for the thickness at each target node, and consequently modify the location used for each target node during the mapping process. See External Data Import for additional information.

Imported Velocity When velocities are transferred to an acoustic analysis, an Imported Velocity object can be inserted to represent the transfer. Imported velocity objects are not supported in MSUP harmonic analyses See the Imported Boundary Conditions (p. 834) section for applicable transfers or for specific steps to transfer data.

Note For surface bodies, the thickness of each target node is ignored when data is mapped. When importing data from an External Data system, the Shell Thickness Factor property enables you to account for the thickness at each target node, and consequently modify the location used for each target node during the mapping process. See External Data Import for additional information.

Note An acoustic analysis is performed via ACT. For information on creating optimization extensions, see the Application Customization Toolkit Developer’s Guide and the Application Customization Toolkit Reference Guide. These documents are part of the ANSYS Customization Suite on the ANSYS Customer Portal.

Spatial Varying Loads and Displacements A spatially varying load or displacement has a variable magnitude in a single coordinate direction (x, y, or z). The following load and displacement types qualify as varying loads and varying displacements, and can be a function of time as well.

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Setting Up Boundary Conditions • Pressure — in a Normal direction only during a structural analysis • Line Pressure — in a Tangential direction only during a structural analysis • Pipe Pressure – during a structural analysis • Pipe Temperature – during a structural analysis • Temperature — during a thermal analysis • Convection — during a thermal analysis • Thermal Condition — during a structural analysis • Displacement for Faces, Edges, or Vertices- during a structural analysis • Nodal Displacement • Nodal Force • Nodal Pressure For spatial varying loads and displacements, the spatial independent variable uses the origin of the coordinate system for its calculations and therefore it does not affect the direction of the load or displacement. To apply a spatial varying load or displacement, set the input as either Tabular or Function in the Details view. You can then view the variable load using the Variable Load toolbar, available on the Environment toolbar. From this toolbar, select the smooth contours effect, the contour bands effect, or the isolines effect. Click Max and Min to toggle the maximum and minimum value label display.

Defining Boundary Condition Magnitude This section describes the methods you can use to define the magnitude of a boundary condition. A load value or magnitude can be defined as: • Constant: defined by a Static value or through an Expression • Tabular Load: defined by varying time, frequency, or space.

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Defining Boundary Condition Magnitude • Function Load: defined by varying time or space.

Note Changing the method of how a multiple-step load value is specified (such as Tabular to Constant), the Activation/Deactivation state of all steps resets to the default, Active.

Support Limitations • Tabular Heat Flow loads applied to an edge in a 3D analysis are not supported. • Function Heat Flow loads applied to an edge in a 3D analysis are not supported. • Function loads are not supported for Explicit Dynamics (LS-DYNA) analyses.

Constant Magnitude Values Once you have scoped the geometry for your boundary condition, generally, the Magnitude option defaults to the Constant setting and you can simply enter your desired magnitude value in the field. As discussed below, you can also define constant values as expressions.

Constant Magnitude Expressions The Magnitude field defaults to the option Constant. Expressions are simply typed into the field. The expression is evaluated and applied. For example and as illustrated, entering the expression =2 + (3 * 5) + pow(2,3) in English in the numeric field is evaluated as a Magnitude of 25.

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Setting Up Boundary Conditions

The equal sign [=] must be used to begin an expression. Additional operators include: +, — , *, /, ^ (for power) and % (integer Modulus). Sample usage: 2+3 10.5-2.5 3.5*3.3 10.12/1.89 2^10 10%3 2*(3+5) The order of operator precedence is: parentheses intrinsic functions (like sin or cos) power (^) multiplication (*), division (/) and integer modulus (%) addition (+) and subtraction (-)

Note If the decimal separator (p. 16) in the current language is a comma (,) as it is in German, then the separator for the list of parameters of a function is a semicolon (;). For example, if an English expression is =2.5 + pow (1.3, 6), the equivalent German expression is =2,5 + pow (1.3; 6). The supported intrinsic functions are: Supported Intrinsic Functions

850

Sample Usage

sin(x)

sin(3.1415926535/2)

sinh(x)

sinh(3.1415926535/2)

cos(x)

cos(3.1415926535/2)

Usage (angles in current Mechanical units setting)

Calculate sines and hyperbolic sines.

cosh(x)

Calculate the cosine (cos) or hyperbolic cosine (cosh). cosh(3.1415926535/2)

tan(x)

tan(3.1415926535/4) Calculate the tangent (tan) or hyperbolic tangent (tanh). Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

Defining Boundary Condition Magnitude Supported Intrinsic Functions

Sample Usage

Usage (angles in current Mechanical units setting)

tanh

tanh(1.000000)

asin(x)

asin(0.326960)

Calculates the arcsine. (x — Value whose arcsine is to be calculated).

acos(x)

acos(0.326960)

Calculates the arccosine. (x — Value between –1 and 1 whose arccosine is to be calculated).

atan(x)

atan(-862.42)

atan2(y,x)

Calculates the arctangent of x (atan) or the arctangent of y/x atan2((atan2). (x,y Any numbers). 862.420000,78.514900)

pow(x,y)

pow(2.0,3.0)

Calculates x raised to the power of y. (x – Base y — Exponent).

sqrt(x)

sqrt(45.35)

Calculates the square root. (x should be a Nonnegative value).

exp(x)

exp(2.302585093)

log(x)

log(9000.00)

Calculates the natural logarithm. (x — Value whose logarithm is to be found).

log10(x)

log10(9000.00)

Calculates the common logarithm. (x — Value whose logarithm is to be found).

rand()

rand() ceil(2.8)

ceil(x)

ceil(-2.8) floor(2.8)

floor(x)

fmod(x,y)

floor(-2.8)

fmod(-10.0, 3.0)

Calculates the exponential. (x — Floating-point value).

Generates a pseudorandom number. Calculates the ceiling of a value. It returns a floating-point value representing the smallest integer that is greater than or equal to x. (x — Floating-point value). Calculates the floor of a value. It returns a floating-point value representing the largest integer that is less than or equal to x. (x — Floating-point value). Calculates the floating-point remainder. The fmod function calculates the floating-point remainder f of x / y such that x = i * y + f, where i is an integer, f has the same sign as x, and the absolute value of f is less than the absolute value of y. (x,y Floating-point values).

You can also enter hexadecimal (starting with 0x) and octal (starting with &) numbers, for example 0x12 and &12.

Tabular Loads For entering a tabular load value, click the flyout arrow in the input field, such as the Magnitude field, choose Tabular (Time) for Static and Transient analysis systems or choose Tabular (Frequency) for a Harmonic Response analysis system, then enter the data in the Tabular Data window. The Graph window displays the variation of the load with time for Static and Transient analysis systems, or frequency for Harmonic analysis system. For time varying loads, annotations in the Geometry window display the current time in the Graph window along with the load value at that time. Tabular Loads allow up to 100,000 entries. For frequency varying loads, annotations in the Geometry window displays the minimum range of harmonic frequency sweep and load value of first frequency entry.

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Setting Up Boundary Conditions

Importing Load History To import a load history from a library: 1.

Select the appropriate geometry on the model and do one of the following: • Click on the appropriate icon on the toolbar and choose the load. OR… • Click right mouse button, select Insert, and choose the load.

2.

Go to the Details view and in the input field, such as the Magnitude field, click on the flyout field and choose Import. Note that the Import feature can present different dependencies, such as time and temperature. Choose the desired load history if it is listed, then click OK. If it is not listed, click the Add button, choose a load history or Browse to one that is stored, then click OK in both dialog boxes.

Exporting Load History To export a load history: By default, any load history that you create in the application remains in the application. To save the load history for future use: 1.

Create a load history using the Graph or Tabular Data windows.

2.

Go to the Details view and in the input field, such as the Magnitude field, click on the flyout field, choose Export, and save the file to a specific location.

Spatial Load Tabular Data When using spatial varying loads, selecting Tabular as the input option displays the Tabular Data and Graph Controls categories in the Details view. The Tabular Data category provides the following options: For a Pressure load, the Define By option must be set to Normal To. • Independent Variable — specifies how the load varies with either Time (or Frequency for a Harmonic Response analysis), the default setting, or in the X, Y, or Z spatial direction. In addition, for Line Pressure loads in a 3D analysis when the Define By property is set to Tangential or Pressure loads in a 2D analysis when the Define By property is set to Normal To, the option Normalized S becomes available. This option allows you to define pressure as a function of the distance along a path whose length is denoted by S. When you select the Normalized S variable, the Tabular Data window accepts input data in the form of normalized values of path length (Normalized S) and corresponding Pressure values. A path length of 0 denotes the start of the path and a 1 denotes the end of the path. Any intermediate values between 0 and 1 are acceptable in the table. Load values are sent to the solver for each element on the defined path based on a first-order approximation.

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Defining Boundary Condition Magnitude • Coordinate System — this property displays if you specify the Independent Variable in a spatial direction (X, Y, or Z). Use this property to define a coordinate system. • Graph Controls — this category displays when you define the Independent Variable as a spatial direction (X, Y, or Z) or as Normalized S. This category provides the property X-Axis which you use to change the Graph window’s display to either Time or to the spatial direction specified in the Independent Variable field. When the X-Axis property is defined as Time: – Tabular Data content can be scaled against time. – You can activate and deactivate the load at a solution load step.

Function Loads For entering a mathematical function, click the flyout arrow in the input field (for example, Magnitude), choose Function, then type a function such as =1000*sin(10*time). Any time values that you are evaluating can exceed the final time value by as much as one time step. The Graph window displays the variation of the load with time. Annotations in the Geometry window display the current time in the Graph window along with the load value at that time.

Spatial Load and Displacement Function Data When using spatial varying loads or displacements, selecting Function as the input option in the Details view presents an editable function field. Enter a mathematical expression in this field. Expressions have the following requirements: • For a Pressure load, the Define By option must be set to Normal To. • For a Line Pressure load, the Define By option must be set to Tangential. • You can use the spatial variation independent variables x, y, or z, and time (entered in lowercase) in the definition of the function. • For Line Pressure loads in a 3D analysis or Pressure loads in a 2–D analysis, you can also use the variable s, which allows you to define pressure as a function of the distance along a path whose length is denoted by s. When defining a path length, valid primary variables you can enter are s alone or s combined with time, for example, s*time, or s*sin(time/s). Load values are sent to the solver for each element on the defined path based on a first-order approximation. • Define only one direction, x, y, or z; or path length, s. After entering a direction or path length, the Graph Controls category (see above) displays. When the Details view property Magnitude is set to Function, the following categories automatically display. • Function — properties include: – Unit System – the active unit system. – Angular Measure – the angular measure that is used to evaluate trigonometric functions. • Graph Controls — based of the defined function, properties include:

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Setting Up Boundary Conditions – X-Axis – This provides options to display time or the spatial independent variable in the graph. When set to Time you can activate and deactivate the load at a solution step. – Alternate Value – If the function combines time and a spatial independent variable, one of these values (alternate) must be fixed to evaluate the function for the two dimensional graph. – Range Minimum – If the X-Axis property is set to a spatial independent variable, this is the minimum range of the graph. For time, this value defaults to 0.0 and cannot be modified. – Range Maximum – If the X-Axis property is set to a spatial independent variable, this is the maximum range of the graph. For time this defaults to the analysis end time and can’t be modified. – Number of Segments — The function is graphed with a default value of two hundred line segments. This value may be changed to better visualize the function. The function can be graphed with up to 100,000 segments.

Caution Specifying larger numbers of points may slow the response time of Mechanical.

Spatial Varying Displacements You can also apply spatial varying displacements, which have the following additional or unique characteristics: • Edge scoping is available. • Displacements are shown as vectors instead of contours except if you choose Normal To the surface. Vectors are only displayed if the model has been meshed. The vector arrows are color-coded to indicate their value. A contour band is included for interpretation of the values. The contour band is the vector sum of the possible three vector components and therefore will only display positive values. • For one Displacement object, you can select up to three displacement components that can all vary using the same direction. If an additional direction is required, you can use an additional Displacement object. • A constant value and a table cannot be used in different components. A table will be forced in any component having a constant value if another component has a table.

Direction There are four types of Direction: Planar Face (p. 855) Edge (p. 855) Cylindrical Face or Geometric Axis Two Vertices (p. 856)

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Defining Boundary Condition Magnitude

Planar Face

Selected planar face. The load is directed normal to the face.

Note Not applicable to rotational velocity. Rotational velocity gets aligned along the normal to a planar face and along the axis of a cylindrical face.

Edge Straight

Colinear to the edge

Circular or Elliptical

Normal to the plane containing the edge

Selected straight edge

Cylindrical Face or Geometric Axis Applies to cylinders, cones, tori, and cylindrical or conical fillets. For vector-based loading on a cylindrical face or geometric axis, you define the radial direction by selecting a different piece of geometry on your model that allows you to modify the Direction in the desired direction.

Selected cylinder

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Setting Up Boundary Conditions

Two Vertices

2 selected vertices

Note Hold the CTRL key to select the second vertex. Loads that require you to define an associated direction include the Define By Details view control. Setting Define By to Vector allows you to define the direction graphically, based on the selected geometry. Setting Define By to Components allows you to define the direction by specifying the x, y, and z magnitude components of the load.

Note If you switch the load direction setting in the Define By field, the data is lost.

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Using Results The Help for Results is organized in the following sections based on analysis type as well as the treatment and usage for the various result options. Introduction to the Use of Results Result Definitions Structural Results Thermal Results Magnetostatic Results Electric Results Fatigue Results User Defined Results Result Outputs Result Utilities

Introduction to the Use of Results Generating results to understand the behavior of an analyzed model is fundamental to any analysis in Mechanical. The application supports a variety of result types and tools to facilitate this process. Some advantageous features include the following capabilities: • Display result contours over the entire, or a portion, of the model for various solution quantities, such as displacement, stress, temperature, and electric field density. • Customized result access using user-defined results. • Chart minimum and maximum values over time for multiple result sets. • Options to quantify and visualization result contours that represent vectors, iso-surfaces, slice planes, path operations, surface cuts, and capped iso-surfaces. • Probes to calculate abstract engineering quantities such as reaction forces, reaction moments, and virtual strain gauges. • Export result data in a variety of formats, such as ASCII files for raw data, static images such as .png, .avi animations, as well as HTML reports.

Result Application To apply Results: • Highlight the Solution object in the tree. Open the desired Solution Context Toolbar menu and select a result item, result probe, or result tool. Or…

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Using Results • Right-click on the Solution object, select Insert, and then choose from the result options.

Note See the User Defined Result section of the Help for more information about the specification and definition of this result type. Once inserted into the tree, you need to scope your result objects to geometric or meshing entities of the model.

Note Any result object clears generated data when it is Suppressed.

Result Definitions The following topics related to result definitions are covered in this section. Applying Results Based on Geometry Scoping Results Solution Coordinate System Material Properties Used in Postprocessing Clearing Results Data Averaged vs. Unaveraged Contour Results Peak Composite Results Layered and Surface Body Results Unconverged Results Handling of Degenerate Elements

Applying Results Based on Geometry The available result objects are based on the given geometry and the analysis type. The following tables outline which bodies can be represented by the various choices available in the drop-down menus and buttons of the Solution toolbar. Static Structural Analysis Geometry

Solution Toolbar Options Deformation

Strain

Stress

Tools

User Defined Result

Solid Body

Total, Directional

All choices

All choices

Stress, Fatigue, Contact1 (p. 861)

Yes

Surface Body

Total, Directional

All choices

All choices

Stress, Fatigue, Contact1 (p. 861)

Yes

Line Body

Total, Directional

None

None

Contact1 (p. 861), Beam

Yes

Transient Analysis Geometry 858

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Result Definitions Deformation

Strain

Stress

Tools

User Defined Result

Solid Body

All choices

All choices

All choices

Stress, Fatigue, Contact1 (p. 861)

Yes

Surface Body

All choices

All choices

All choices

Stress, Fatigue, Contact

Yes

All

None

None

Contact1 (p. 861), Beam

Yes

Line Body

Modal and Linear Buckling Analyses Geometry

Solution Toolbar Options Deformation

Strain

Stress

Tools

User Defined Result

Solid Body

Total, Directional

All applicable choices, except Energy

All choices

None

Yes

Surface Body

Total, Directional

All applicable choices, except Energy

All choices

None

Yes

Line Body

Total, Directional

None

None

None

Yes

Random Vibration Analysis Geometry

Solution Toolbar Options Deformation

Strain

Stress

Tools

User Defined Result

Solid Body

Directional, Directional Velocity, Directional Acceleration

Normal, Shear

Equivalent (von-Mises), Normal, Shear

None

No

Surface Body

Directional, Directional Velocity, Directional Acceleration

Normal, Shear

Equivalent (von-Mises), Normal, Shear

None

No

Line Body

Directional, Directional Velocity, Directional Acceleration

None

None

None

No

Response Spectrum Analysis

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Using Results Geometry

Solution Toolbar Options Deformation

Strain

Stress

Tools

User Defined Result

Solid Body

Total, Directional, Directional Velocity, Directional Acceleration

Normal, Shear

Equivalent (von-Mises), Normal, Shear

None

No

Surface Body

Total, Directional, Directional Velocity, Directional Acceleration

Normal, Shear

Equivalent (von-Mises), Normal, Shear

None

No

Line Body

Total, Directional, Directional Velocity, Directional Acceleration

None

None

None

No

Steady-State Thermal and Transient Thermal Analyses Geometry

Solution Toolbar Options Thermal

User Defined Result

Solid Body

All choices

Yes

Surface Body

All choices

Yes

Temperature

Yes

Line Body Magnetostatic Analysis Geometry

Solution Toolbar Options Electromagnetic

Solid Body Surface Body Line Body

All choices

User Defined Result

2 (p. 861)

Yes

Not Applicable

Yes

None

Yes

Electric Analysis Geometry

Solution Toolbar Options Electric

User Defined Result

All choices

Yes

Surface Body

Yes

Yes

Line Body

Yes

Yes

Solid Body

Harmonic Analysis (Deformation, Strain, Stress)

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Result Definitions Geometry

Solution Toolbar Options Deformation

Strain

Stress

Solid Body

All choices

3 (p. 861)

All choices, except Energy, Thermal, Equivalent Plastic

All choices

Surface Body

All choices3 (p. 861)

All choices, except Energy, Thermal, Equivalent Plastic

All choices

All choices

None

None

Line Body

Harmonic Analysis (Frequency Response, Phase Response, User Defined Result) Geometry

Solution Toolbar Options Frequency Response3 (p. 861)

Phase Response3 (p. 861)

User Defined Result

Solid Body

All choices

All choices

No

Surface Body

All choices

All choices

No

Line Body

All choices

All choices

No

1 — Contact results are not reported, and are not applicable to the following: • Edges. • MPC contact. • Target side of asymmetric contact. 2 — Electric Potential can only be scoped to conductor bodies. 3 — See Harmonic Analysis section.

Scoping Results All result objects can be scoped to: • Geometry selections — edges, a single vertex, faces, parts, bodies, or the entire assembly. • Geometry-based Named Selections. • Node-based Named Selections • Node selections of the underlying mesh. • Element-based Named Selections. • Element selections of the underlying mesh.

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Using Results See the Results Context Toolbar section for additional information about how results are graphically represented following a solution.

Note Direct graphical node or element selection requires you to generate the mesh and have the Show Mesh tool turned on.

Node-Based Scoping The following are known characteristics related to node-based scoping: • If all nodes of an element face are scoped, then Mechanical will draw contour bands on the entire face. • If some nodes of an element face are not scoped, then Mechanical will draw the face as transparent and draw the scoped nodes in contour colors. • As is the case with other scoping that occurs within a body (such as vertex or edge), any applicable averaging is done considering all of the nodes on a body.

Element-Based Scoping Unlike results scoped to geometries or nodes, results scoped to elements evaluate only the scoped elements. No adjacent elements are considered. The example results show below illustrate this behavior. Refer to the Averaged vs. Unaveraged Contour Results section of the Help for additional information on this topic. The following results illustrate contour bands for all nodes. Global Averaged Result

Global Unaveraged Result

Max. = 205 and Min. = -50

Max. = 276 and Min. = -74

The following results illustrate contour bands for elements only. Result Scoped to One Element Max. = 276: Matches the Global Unaveraged Result (Min. Value = 127)

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Result Scoped to Three Elements Max. = 205: Matches the Global Averaged Result Min. = -74: Matches the Global Unaveraged Result

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Result Definitions

Support Requirements Make sure that your result objects conform to the following: • Once a solution is computed, the scope of the result object cannot change. You must either add a new result object with the desired scope, or you can right mouse click on that result item, and choose Clear Generated Data to change its scope. • Result scoping has an impact on convergence. Refinement does not happen outside the scope for a given convergence control. Multiple convergence controls are possible, however.

Solution Coordinate System Solution Coordinate System is available as a Coordinate System option in the Details view for most result objects. If you are familiar with the Mechanical APDL application commands, Solution Coordinate System is an implementation of the RSYS,SOLU command, where for element results, such as stress, a coordinate system is produced for each element. If these individual element coordinate systems are aligned randomly, you can re-align them to a local coordinate system to obtain a uniform alignment. Viewing results in the element solution coordinate system has value since results in a local coordinate system aligned with a certain shell direction are typically more meaningful than results in a global coordinate system. For example, seeing bending and in-plane stresses have meaning in a local coordinate system, but have no meaning in a global coordinate system.

Application The following are typical applications for viewing results in a solution coordinate system: • Viewing results in a particular direction for surface bodies or “solid shell” bodies, that is, solids meshed with the Solid Shell element option (see the Meshing Help: Sweep description in the Method Control section). • Viewing results in a random vibration, spectrum, or surface bodies in an explicit dynamics analysis. Results for these analysis types only have meaning in a solution coordinate system.

Background The meshing of surface bodies and solid shell bodies result in coordinate systems whose alignment is on a per element basis, in contrast to solid body element types whose coordinate systems are aligned with the global coordinate system by default. Surface body alignment on a per element basis can lead to results with totally random alignment directions as shown below.

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Using Results

To produce meaningful results for surface body and solid shell bodies, you can re-align the random direction of each element’s solution coordinate systems to a uniform direction of a local coordinate system. An example is shown below.

Procedure To correct for random coordinate system alignments in surface bodies and solid shell bodies, and to ensure a consistent alignment: 1. For each part, create a local coordinate system to specify the alignment of the elements of the part. 2. Choose the Solution Coordinate System option for the result.

Note • The Coordinate System setting for result objects in a random vibration, spectrum, or explicit dynamics analysis is set to Solution Coordinate System by default and cannot be changed because the results only have meaning when viewed in the solution coordinate system. • The solution coordinate system is not supported by explicit dynamics analyses for results.

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Result Definitions

Material Properties Used in Postprocessing The material properties listed below are used in postprocessing calculations to produce the displays of probe and contour results. For reference, the corresponding labels (Lab argument) for the MP command in Mechanical APDL are included in parentheses. • Elasticity modulus (EX, EY, EZ) • Shear modulus (GXY, GYZ, GXZ) • Poisson’s ratio (NUXY, NUYZ, NUXZ) • Thermal conductivities (KXX, KYY, KZZ) • Magnetic permeability (MURX, MURY, MURZ) The following results, together with their identifiers (see User Defined Results (p. 970)), are directly affected by the material property values: • Equivalent Strain — uses only NUXY Poisson’s ratio 1. Plastic (EPPL) and Creep (EPCR) strain always use NUXY = 0.5. 2. Elastic (EPEL), Thermal (EPTH) and Total (EPTO) default to 0.0. • Structural Error — uses elasticity modulus, shear modulus and Poisson’s ratio. • Thermal Error — uses thermal conductivities • Magnetic Error — uses magnetic permeability An error message is generated if an associated material property is not defined when evaluating Structural, Thermal or Magnetic Error result. If Poisson’s ratio is not defined when evaluating Equivalent Strain, the Poisson’s ratio will assume a zero value. Other results affected by material property values include Stress Tool and Fatigue Tool results.

Note If a material property is temperature dependent, it is evaluated at the reference temperature of the body to be used in the computation for the result.

Clearing Results Data You can clear results and meshing data from the database using the Clear Generated Data command from the File menu, or from a right-mouse click menu item. This reduces the size of the database file, which can be useful for archiving.

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Using Results To clear all results data, simply select the Solution object and choose the Clear Generated Data menu item from the File menu or from a right-mouse click menu. You can clear individual results by selecting a result object before choosing the Clear Generated Data menu item.

Note Anytime the geometry or mesh has been changed, you should clear all results data. If meshes become obsolete, the solution and results are totally cleared.

Averaged vs. Unaveraged Contour Results Normally, contour results in the Mechanical application are displayed as averaged results. Some results can also display as unaveraged contours. Averaged contours distribute the average elemental nodal results across element and geometric discontinuities. A user option exists that allows you to control whether results are also averaged across body boundaries that contain a conformal mesh. The default setting does not calculate an average across bodies. Using the Mechanical APDL application terminology, unaveraged contour results display as element nodal contours that vary discontinuously even across element boundaries. These contours are determined by linear interpolation within each element and are unaffected by surrounding elements (that is, no nodal averaging is performed). The discontinuity between contours of adjacent elements is an indication of the gradient across elements. Results that include the unaveraged contour display option are most elemental quantities such as stress or strain. This option is not available for degree of freedom results such as displacements. Nodal averaging of element quantities involves direct averaging of values at corner nodes. For higherorder elements, midside node results are then taken as the average of the corner nodes. There are two distinct techniques for calculating averaged nodal results. The calculation for the first technique is as follows: 1.

Average the component (X, Y, Z, XY, YZ, XZ) stress values from the elements at a common node.

2.

Calculate the equivalent stresses from the averaged component values

The calculation for the second technique is as follows: 1.

Calculate the equivalent stress values (from the six component strains) on a per element basis.

2.

Average these values from the elements at a common node.

For equivalent stress, stress/strain intensity, max shear stress/strain, and principal stresses/strains, the first technique is used to calculate the results. For equivalent strains, which are calculated by the Mechanical APDL solver, the second technique is used. For random vibration analysis, equivalent stresses are calculated by the Mechanical APDL solver using the Segalman method, so the second technique is also used.

Note If an elemental result is scoped to a surface body, then there may be two sets of results at each node (Top and Bottom) and sometimes a third set of results (Middle). At release 12.0,

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Result Definitions if the solver writes Middle results to the result file, then Mechanical displays these results if the Shell Face setting in the Details view equals Middle (Membrane). If the solver did not write Middle results to the result file, then Mechanical displays the average of Top and Bottom if the Shell Face setting in the Details View is Middle (Membrane). For a given node on the shell, the Mechanical application will average Top results, separately average Bottom results, and separately average Middle results. When you export a result in the Mechanical application that is set to Top/Bottom, you may note that a node number is repeated in the Excel file. This is because both the Top and Bottom stresses are listed. You can display contour results by setting the Display Option field to one of the following: • Unaveraged: Displays unaveraged results. • Averaged (default): Displays averaged results. • Nodal Difference: Computes the maximum difference between the unaveraged computed result (for example, total heat flux, equivalent stress) for all elements that share a particular node. • Nodal Fraction: Computes the ratio of the nodal difference and the nodal average. • Elemental Difference: Computes the maximum difference between the unaveraged computed result (for example, total heat flux, equivalent stress) for all nodes in an element, including midside nodes. • Elemental Fraction: Computes the ratio of the elemental difference and the elemental average. • Elemental Mean: Computes the elemental average from the averaged component results. Characteristics of unaveraged contour displays: • Because of the added data involved in the processing of unaveraged contour results, these results take a longer time to display than averaged results. • Occasionally, unaveraged contour result displays tend to resemble a checkerboard pattern. • Capped Isosurface displays can have missing facets.

Average Across Bodies When you select Averaged as the Display Option, the Average Across Bodies property displays in the Integration Point Results category. Setting this property to Yes (the default value is No) allows you to averages the results across separate bodies on your model. This post-processing feature is supported for most averaged element nodal contour results (like stress, strain, and thermal flux). If a node belongs to two different bodies, its averaged stress value of one of the bodies is typically different from the stress value of the other body. Using the Average Across Bodies feature, the average value at this node is the sum of all of the stress values from all “scoped” elements that contain the node (divided by the number of elements). The feature graphically renders a smoother result contour at the interfaces of bodies. If bodies do not share any nodes, then the feature has no effect. Calculation Conditions Note the following conditions and characteristics for calculating averages across bodies:

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Using Results • Principal values themselves are averaged when averaging results across bodies for principal and vector sums. Calculated results, such as the types shown below, are averaged at the nodes at the interfaces of bodies. That is, they do not average the components (SX, SY, etc.) across bodies. For example, this feature averages equivalent stress (SEQV) values directly: SEQV(node_1) + SEQV(node_2) + SEQV(node_N)/N This differs from the usual method (except for equivalent strain) of averaging the components and then computing SEQV. – Principal Stresses (1, 2, 3) – Stress Intensity (INT) – Equivalent Stress (EQV) – Principal Strains (1, 2, 3) – Strain Intensity (INT) – Equivalent Strain (EQV) – Total Thermal Flux The following result illustrations show the outcomes between not performing an average calculation, performing an average calculation but not across bodies, and performing an average calculation across bodies. No Averaging Performed

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Result Definitions

No Averaging Across Bodies Performed

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Using Results

Averaging Across Bodies Performed

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Result Definitions

• If the associated bodies have different material properties, such as Poisson’s ratios, then, because this feature averages quantities like equivalent elastic strain at common nodes, you may see unexpected results at the interfaces. The Poisson Ratio employed to calculate elastic equivalent in one body may be significantly different from the Poisson Ratio employed to calculate elastic equivalent in a different body. Therefore, in this scenario, averaging across bodies at the interface is not recommended. • If you choose to compare this feature against MAPDL PowerGraphics with AVRES,1,FULL in effect, PowerGraphics employs the effective Poisson’s ratio in the AVPRIN,KEY,EFFNU command. The EFFNU value may not match the Poisson’s ratios in all bodies. PowerGraphics also calculates equivalent strain from the average component strains if KEY (in the AVPRIN command) is set to ZERO. As a result, there may be differences between this feature and PowerGraphics when the AVRES,1,FULL command is employed. Support Limitations The following results features are not supported: • Probe results • Results in cyclic symmetry analyses • Results on line bodies

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Using Results

Averaging Element Nodal Results For element nodal results like stresses, strains, or contact results, the Mechanical solvers write (unaveraged) values for corner nodes to the result file. No element nodal results are written for mid-side nodes. To derive the value at a mid-side node, the Mechanical post processor must employ the values at the corner nodes. There are two distinct techniques: 1. For line elements, such as beams and pipes, Mechanical calculates the average of the unaveraged values of those corner nodes which share an edge with the mid-side node — corner nodes, node I and node J. 2. For elements like quadrilaterals, shells, tetrahedrons, hexagonals, and other non-line elements, Mechanical calculates the average of the averaged values of those corner nodes which share an edge with the mid-side node. For some meshes, this process can lead to averaged results that may be unexpected. Consider the following example consisting solely of high order line elements, where: • Element 1 contains nodes 1, 2, and 12. • Element 2 contains nodes 2, 3, and 23. • Element 3 contains nodes 3, 4, and 34. • Nodes 12, 23, and 34 are mid-side nodes.

If: • The element nodal solution for element 1 is 0.0 and 0.0 for nodes 1 and 2. • The element nodal solution for element 2 is 100 and 80 for nodes 2 and 3. • The element nodal solution for element 3 is 3 and 0.0 for nodes 3 and 4. The unaveraged solution is then: • The value at node 12 is the average of the values at the associated element’s end points, namely 0.0. • The value at node 23 is the average of the values at the associated element’s end points, namely 90. • The value at node 34 is the average of the values at the associated element’s end points, namely 1.5.

For the averaged solution of nodes 2 and 3:

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Result Definitions • The value at node 2 is 50. • The value at node 3 is 41.5.

Note that the value at the mid-side node 23 (90) exceeds the values at the end points. The following is a 2D model that demonstrates the mid-side averaging technique for non-line elements. The average mid-side node data does not demonstrate the quirks seen for line elements.

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Using Results

Peak Composite Results With this feature you can view the result contours over an independent variable such as time in a static or transient structural analysis, or frequency/phase in a harmonic analysis, or cyclic phase in a cyclic modal analysis. Using time as an example, the color in the contour represents one of the following: the results at the specified time, the results for the specified set, the maximum result over time or the time when the maximum result occurred for the node, element, or sample point. To view peak composite results:

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Result Definitions 1.

Insert a result under solution.

2.

In the Details view, under Definition, click the By list and select the result view. Choices are the following:

• Maximum Over Time or Time of Maximum: Each node/element/sample point is swept through the result sets to find its maximum result. Either the result itself is reported (sometimes referred to as a «peak hold») or the time at which the peak occurred is reported. This result is applicable in static and transient analyses. • Maximum Over Frequency or Frequency of Maximum: With these options chosen, the phase specified in the Sweeping Phase property is held constant and each node/element/sample point is swept through frequency range to find its maximum result. This result is applicable during a Harmonic Response analysis only. • Maximum Over Phase or Phase of Maximum: With these options chosen, frequency is held constant and each node/element/sample point is swept through a phase period of 0o to 360o at specified increments to find its maximum result. You can control the increment using the Phase Increment entry. This result is applicable during a Harmonic Response analysis only. • Maximum Over Cyclic Phase or Cyclic Phase of Maximum: Each node/element/sample point is swept through a phase angle of 0o to 360o in 10 degree increments find its maximum result. This result is applicable during a cyclic modal analysis only and for harmonic indices greater than zero.

Note There is no affiliation between composite results and composite elements.

Layered and Surface Body Results For surface bodies, stress and strain results at the top and bottom faces are displayed simultaneously, by default. (See Surface Body Shell Offsets (p. 378) for information on identifying the top and bottom faces.) The contours vary linearly through the thickness from the top face to the bottom face. However you can choose to display only the Top, Middle, or Bottom stress/strains in the Details view of the result item. Selecting Top, Middle, or Bottom will display the result at the selected location as a uniform contour through the thickness. Middle Stresses • Normal and Shear results The middle stresses are calculated at the shell mid-surface or at each layer mid-surface if layers are present. The Middle option for Shell gives the actual result values at the mid-surface if the solver was directed to calculate these results. In Mechanical APDL terminology, the solver computes results at mid-surface if KEYOPT(8) for the shell element is set to 2 at the time of element creation. Otherwise, the Middle results are computed as the average of the Top and Bottom results, that is, (Top + Bottom) / 2. Note that these results are valid only for linear analyses. • Equivalent and Principal results These results are derived from the Normal and Shear results. Hence the Normal and Shear component results for Middle are computed first, and then the Equivalent and Principal results are derived. Element Nodal results (like stress/strain), as well as EDIR- and PNUM-type Elemental results, can be plotted on a specific layer by entering the desired Layer number in the Details view of the result object. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Results Elemental results outputting volume or energy are calculated for the entire element, regardless of the requested layer. If the Layer specified does not exist for a particular surface body, the display of the result will be translucent with zero values for minimums and maximums on that body. If you enter 0 for Layer, it defaults to the Entire Section.

Note • A Layer number must be specified to calculate the Middle stresses and strains. If you set Layer to 0 (Entire Section) while Shell is Middle, the Shell option will become invalid. Similarly, if you have Layer set to Entire Section and you try to set Shell to Middle, Shell will become invalid. • If there is a Layered Section in the model, convergence is not supported for results. • If Layer is Entire Section, Top stresses and strains are for the top surface of the topmost layer and the Bottom stresses and strains are for the outer surface of the bottom layer. • If a Layered Section is present in the model and you enter a number larger than the maximum number of layers that exists in the model, the Layer field will become invalid. • All stress tool results and all fatigue tool results are unsupported if Layered Sections are present in the model. • Only results from the section top and bottom are available on hyperelastic layered shells. Thus no results will be reported on such bodies if the layer is not set to 0 «Entire Section».

For Explicit Dynamics Layer Results Normal/shear stresses and strains are available in global and solution coordinate systems. Stress and strain results for individual layers may be selected by using the Layer property in the result’s Details view. Only a single result is available per layer.

Unconverged Results A nonlinear analysis may fail to converge due to a number of reasons. Some examples may be initially open contact surfaces causing rigid body motion, large load increments, material instabilities, or large deformations that distort the mesh resulting in element shape errors. In the Mechanical application, you can review this unconverged result as well as any converged results at previous time points. These results are marked in the legend of contour/vector plots as ‘Unconverged’ indicating that these results must be used only for debugging purposes. Note that a plot of NewtonRaphson residuals is a very useful tool to identify regions of your structure that led to the convergence difficulty.

Note • Results in Solution Combination objects that use partial solutions will not be solved. You can view partial results but cannot use them in further post/solution work.

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Structural Results • Newton-Raphson residuals is a very useful tool to identify regions of your structure that led to the convergence difficulty. • The handling of unconverged solutions is the same for both probes and results, with the following exception: reaction probes scoped to a Compression Only boundary condition cannot display results if the solver did not converge.

Handling of Degenerate Elements The finite element method can create elements that are classified as degenerate. For example, a quad element, with four nodes 1, 2, 3, and 4, may contain duplicate nodes 3 and 4. In this case, node 3 and 4 are located at the same (x, y, z).

The degenerate quad element (above, right) contains three distinct nodes and four distinct integration (Gauss) points. MAPDL’s solver calculates element nodal results (like stress and strain and flux, et. al.) at each of the integration points. Hence, element nodal results in the MAPDL result file are stored as though an element is not degenerate (even when it is degenerate). For the element (above, right), the file would contain stress and strain and flux listings for four nodes, 1, 2, 3, and 4. At nodes that share the same (x,y,z) in an element, it is not necessarily true that the element nodal results are equal for each coincident node. Depending upon the analysis, the element nodal results for the element (above, right) at node 3 may not equal the element nodal results at node 4. During the post processing phase, Mechanical drops the values of all but the first duplicate node at an (x,y,z). The element (above, right) would display the stress and strain and flux contours for nodes 1, 2, and 3 (but not 4).

Structural Results The following structural result topics are addressed in this section: Deformation Stress and Strain Stabilization Energy Strain Energy Linearized Stress Damage Results Contact Results Frequency Response and Phase Response Stress Tools Fatigue (Fatigue Tool) Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Results Fracture Results Contact Tool Beam Tool Beam Results Structural Probes Gasket Results Campbell Diagram Chart Results Stress Tools (p. 904) are used to determine the following results: • Maximum Equivalent Stress Safety Tool (p. 905) • Maximum Shear Stress Safety Tool (p. 907) • Mohr-Coulomb Stress Safety Tool (p. 908) • Maximum Tensile Stress Safety Tool (p. 910) Structural Probes (p. 926) can be used to determine the following results: • Deformation • Strain • Position • Velocity • Angular Velocity • Acceleration • Angular Acceleration • Energy • Force Reaction • Moment Reaction • Joint • Response PSD • Spring • Bearings • Beam • Bolt Pretension • Generalized Plane Strain

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Structural Results

Deformation Physical deformations can be calculated on and inside a part or an assembly. Fixed supports prevent deformation; locations without a fixed support usually experience deformation relative to the original location. Deformations are calculated relative to the part or assembly world coordinate system.

Component deformations (Directional Deformation) Deformed shape (Total Deformation vector) The three component deformations Ux, Uy, and Uz, and the deformed shape U are available as individual results. Scoping is also possible to both geometric entities and to underlying meshing entities (see example below). Numerical data is for deformation in the global X, Y, and Z directions. These results can be viewed with the model under wireframe display, facilitating their visibility at interior nodes.

Example: Scoping Deformation Results to Mesh Nodes The following example illustrates how to obtain deformation results for individual nodes in a model. The nodes are specified using criteria based named selections. 1. Create a named selection by highlighting the Model tree object and clicking the Named Selection toolbar button. 2. Highlight the Selection object and in the Details view, set Scoping Method to Worksheet. 3. In the Worksheet, add a row and set the following items for the row. Refer to Specifying Named Selections using Worksheet Criteria (p. 434) for assistance, if needed. • Entity Type = Mesh Node. • Criterion = Location X. • Operator = Greater Than. • Value = 0.1. 4. Add a second row with Criterion = Location Y, Value = 0.2, and all remaining items set the same as the first row. 5. Add a third row with Criterion = Location Z, Value = 0.3, and all remaining items set the same as the first row. The table displays as shown below

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Using Results

6. Click the Generate button. The Geometry field in the Details view displays the number of nodes that meet the criteria defined in the Worksheet.

7. After applying loads and supports to the model, add a Total Deformation result object, highlight the object, set Scoping Method to Named Selection, and set Named Selection to the Selection object defined above that includes the mesh node criteria. Before solving, annotations are displayed at each selected node as shown below.

8. Solve the analysis. Any element containing a selected node will display a contour color at the node. If all nodes on the element are selected, the element will display contour colors on all facets. Element facets that contain unselected nodes will be transparent. An example is shown below.

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Structural Results

Note that all element facets are drawn, not just the facets on the surface or skin of the model. To possibly reduce clutter for complex models, the size of the dots representing the nodes can be changed by choosing View> Large Vertex Contours.

Working with Deformations Deformations can be used to • Set Alert objects. • Control accuracy and convergence and to view converged results. • Study deformations in a selected or scoped area of a part or an assembly.

Velocity and Acceleration In addition to deformation results, velocity and acceleration results are also available for Transient Structural, Rigid Dynamics, Random Vibration, and Response Spectrum analyses. Both total and directional components are available for the Transient Structural analyses but only directional components are available for Random Vibration and Response Spectrum.

Considerations for Random Vibration For Random Vibration analyses, only component directional deformations are available because the directional results from the solver are statistical in nature. The X, Y, and Z displacements cannot be combined to get the magnitude of the total displacement. The same holds true for other derived quantities such as principal stresses. Directional Deformation, Directional Velocity, and Directional Acceleration result objects in Random Vibration analyses also include the following additional items in the Details view:

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Using Results • Reference — Read-only reference indication that depends on the directional result. Possible indications are: – Relative to base motion for a Directional Deformation result. – Absolute (including base motion) for a Directional Velocity or Directional Acceleration result. • Scale Factor — A multiple of standard deviation values (with zero mean value) that you can enter which determines the probability of the time the response will be less than the standard deviation value. By default, the results output by the solver are 1 Sigma, or one standard deviation value. You can set the Scale Factor to 2 Sigma, 3 Sigma, or to User Input, in which case you can enter a custom scale factor in the Scale Factor Value field. • Probability — Read-only indication of the percentage of the time the response will be less than the standard deviation value as determined by your entry in the Scale Factor field. A Scale Factor of 1 Sigma = a Probability of 68.3 %. 2 Sigma = 95.951 %. 3 Sigma = 99.737 %.

Stress and Strain Stress solutions allow you to predict safety factors, stresses, strains, and displacements given the model and material of a part or an entire assembly and for a particular structural loading environment. A general three-dimensional stress state is calculated in terms of three normal and three shear stress components aligned to the part or assembly world coordinate system. The principal stresses and the maximum shear stress are called invariants; that is, their value does not depend on the orientation of the part or assembly with respect to its world coordinate system. The principal stresses and maximum shear stress are available as individual results. The principal strains ε1, ε2, and ε3 and the maximum shear strain γmax are also available. The principal strains are always ordered such that ε1> ε2> ε3. As with principal stresses and the maximum shear stress, the principal strains and maximum shear strain are invariants. You can choose from the following stress/strain results: Equivalent (von Mises) Maximum, Middle, and Minimum Principal Maximum Shear Intensity Vector Principals Error (Structural) Thermal Strain Equivalent Plastic Strain Equivalent Creep Strain Equivalent Total Strain Membrane Stress Bending Stress Normal (X, Y, Z) and Shear (XY, YZ, XZ) stress and strain results are also available. It is assumed that whatever holds true for stress applies to strain as well. However, the relationship between maximum shear stress and stress intensity does not hold true for an equivalent relationship between maximum shear strain and strain intensity. For more information about Stress/Strain, see the Mechanical APDL Theory Reference. 882

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Structural Results

Considerations The degree of uncertainty in the numerical calculation of Stress answers depends on your accuracy preference. See Adaptive Convergence (p. 1065) for information on available options and their effect on Stress answers. For your convenience and future reference, Report can include stress, strain, and deformations value, convergence histories, and any alerts for these values.

Equivalent (von Mises) Equivalent stress is related to the principal stresses by the equation: 1/ 2  σ −σ 2 + σ −σ 2 + σ −σ 2 1 2 2 3 3 1 σe =    

Equivalent stress (also called von Mises stress) is often used in design work because it allows any arbitrary three-dimensional stress state to be represented as a single positive stress value. Equivalent stress is part of the maximum equivalent stress failure theory used to predict yielding in a ductile material. The von Mises or equivalent strain εe is computed as:  ε = + ν 

      ε −ε + ε − ε + ε − ε
  
 



where: ν’ = effective Poisson’s ratio, which is defined as follows: • Material Poisson’s ratio for elastic and thermal strains computed at the reference temperature of the body. • 0.5 for plastic strains.

Note Currently, for Linked MSUP analyses with the Expand Results From detail under Output Controls set to Modal Solution, the MAPDL solver does not calculate equivalent strains. If you choose to display equivalent strain results, you will see zero contours.

Maximum, Middle, and Minimum Principal From elasticity theory, an infinitesimal volume of material at an arbitrary point on or inside the solid body can be rotated such that only normal stresses remain and all shear stresses are zero. The three normal stresses that remain are called the principal stresses: σ1 — Maximum σ2 — Middle σ3 — Minimum Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Results The principal stresses are always ordered such that σ1 > σ2 > σ3.

Maximum Shear The maximum shear stress τmax, also referred to as the maximum shear stress, is found by plotting Mohr’s circles using the principal stresses:

or mathematically through: σ − σ3 τmax = 1 For elastic strain, the maximum shear elastic strain γmax is found through: γmax = ε1 — ε3 since the shear elastic strain reported is an engineering shear elastic strain.

Intensity Stress intensity is defined as the largest of the absolute values of σ1 — σ2, σ2 — σ3, or σ3 — σ1: σI =

( σ − σ 2 σ 2 − σ
σ
− σ )

Stress intensity is related to the maximum shear stress: σI = 2τmax Elastic Strain intensity is defined as the largest of the absolute values of ε1 — ε2, ε2 — ε3, or ε3 — ε1: ε =

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( ε − ε ε − ε ε − ε )

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Structural Results Elastic Strain intensity is equal to the maximum shear elastic strain: εI = γmax Equivalent Stress (and Equivalent Elastic Strain) and Stress Intensity are available as individual results.

Note Computation of Equivalent Elastic Strain uses Poisson’s ratio. If Poisson’s ratio is temperature dependent then the Poisson’s ratio value at the reference temperature of the body is used to compute the Equivalent Elastic Strain.

Vector Principals A Vector Principals plot provides a three-dimensional display of the relative size of the principal quantities (stresses or elastic strains), and the directions along which they occur. Positive principals point outwards and negative ones inwards. Plots of Vector Principals help depict the directions that experience the greatest amount of normal stress or elastic strain at any point in the body in response to the loading condition. The locus of directions of maximum principal stresses, for example, suggests paths of maximum load transfer throughout a body. Request a Vector Principals plot in the same way that you would request any other result. Scoping is also possible. Numerical data for these plots can be obtained by exporting the result values to an .XLS file. These files have 6 fields. The first three correspond to the maximum, middle, and minimum principal quantities (stresses or elastic strains). The last three correspond to the Mechanical APDL application Euler angle sequence (CLOCAL command in the ANSYS environment) required to produce a coordinate system whose X, Y and Z-axis are the directions of maximum, middle and minimum principal quantities, respectively. This Euler angle sequence is ThetaXY, ThetaYZ, and ThetaZX and orients the principal coordinate system relative to the global system. These results can be viewed using the Graphics button, so that you can use the Vector Display toolbar.

Error (Structural) You can insert an Error result based on stresses to help you identify regions of high error and thus show where the model would benefit from a more refined mesh in order to get a more accurate answer. You can also use the Error result to help determine where Mechanical will be refining elements if Convergence is active. The Error result is based on the same errors used in adaptive refinement. Information on how these errors are calculated is included in POST1 — Error Approximation Technique, in the Theory Reference for ANSYS and ANSYS Workbench.

Note The Error result is based on linear stresses and as such may be inaccurate in certain nonlinear analyses (for example, when plasticity is active). Furthermore, the Error result is currently restricted to isotropic materials. You may wish to refer to the Structural Material Properties section of the Engineering Data help for additional information. Presented below are example applications of using the Error result in a Structural simulation. 3D Model: Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Results

2D Model, Base Mesh:

2D Model, Adaptive Refinement (Convergence Added):

2D Model, With Mesh Control:

Thermal Strain Thermal strain is computed when coefficient of thermal expansion is specified and a temperature load is applied in a structural analysis. To specify the coefficient of thermal expansion, you must set Thermal Strain Effects to Yes in the Details view of the part or body objects before initiating a solve. Each of the components of thermal strain are computed as:

Where:

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Structural Results — thermal strain in one of the directions x, y, or z. — Secant coefficient of thermal expansion defined as a material property in Engineering Data (see “Chapter 2.4 Linear Material Properties” in the Element Reference of the Mechanical APDL application Help for more information about the secant function). — reference temperature or the «stress-free» temperature. This can be specified globally for the model using the Reference Temperature field of Static Structural or Transient Structural analysis types. Optionally you can also specify the reference temperature as a material property for cases such as the analysis for cooling of a weld or solder joint where each material has a different stress-free temperature.

Equivalent Plastic Strain The equivalent plastic strain gives a measure of the amount of permanent strain in an engineering body. The equivalent plastic strain is calculated from the component plastic strain as defined in the Equivalent stress/strain section. Most common engineering materials exhibit a linear stress-strain relationship up to a stress level known as the proportional limit. Beyond this limit, the stress-strain relationship will become nonlinear, but will not necessarily become inelastic. Plastic behavior, characterized by nonrecoverable strain or plastic strain, begins when stresses exceed the material’s yield point. Because there is usually little difference between the yield point and the proportional limit, the Mechanical APDL application assumes that these two points are coincident in plasticity analyses. Stress Yield Point

Proportional Limit

Strain Plastic Strain

In order to develop plastic strain, plastic material properties must be defined. You may define plastic material properties by defining either of the following in the Engineering Data: • Bilinear Stress/Strain curve. • Multilinear Stress/Strain curve.

Note Yield stresses defined under the Stress Limits section in the Engineering Data are used for the post tools only (that is, Stress Safety Tools and Fatigue tools), and do not imply plastic behavior.

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Equivalent Creep Strain Creep is a rate-dependent material nonlinearity in which the material continues to deform under a constant load. The material deforms under an initial applied load and the load diminishes over time with an increase in deformation or creep strain. The equivalent creep strain gives a measure of the amount of the creep strain in an engineering body. The equivalent creep strain is calculated from component creep strains. In order to develop creep strain, creep material properties must be defined. You may define creep material properties by choosing one of the available 13 creep models in Engineering Data. This result type is available in Mechanical only after you have selected a creep material for at least one prototype in the analysis.

Equivalent Total Strain The equivalent total strain gives a total value of strain in any engineering body. The total strain components are calculated by addition of components of elastic, plastic, thermal, and creep strains and then equivalent total strain is calculated from total strain components. This result type is available in Mechanical only if at least one of the other three strain results is available for post processing. In Mechanical APDL this strain in called Total Mechanical and Thermal Strain.

Membrane Stress Membrane stress calculates the stresses along the thickness of the shell in longitudinal direction, in transverse direction, and in plane shear. The result is available only for shell bodies and solids that are meshed using the thin-solid meshing option. Each element of the body can display individual stress values and give a checkboard appearance to the result contours. The results are calculated in the element coordinate system. Shell membrane stress tensor (s11m, s22m, s12m) is the average of the in-plane stress tensor (s11(z), s22(z), s12(z)) along the shell thickness direction: t

∫σ

σ 11m =

11 z dz

0

 22



σ =





∫σ

22  

σ =

∫σ

 

Where: t is the total shell thickness, z is the thickness location where the in-plane stress is evaluated.

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Structural Results Unlike linearized stress in other elements, a pre-defined path through the shell thickness is not required in order to compute shell membrane stress.

Note Make sure that the Output Control, General Miscellaneous is set to Yes or your results may be under-defined.

Bending Stress The result is available only for shell bodies and solids that are meshed using the thin-solid meshing option and are calculated in the element coordinate system. Each element of the body can display individual stress values and give a checkboard appearance to the result contours. Shell bending stress tensor (s11b, s22b, s12b) represents the linear variation portion of the in-plane stress tensor (s11(z), s22(z), s12(z)) along the shell thickness direction: t

b 11

σ =

2

∫σ

11 z

0

 σ

=

σ   =





∫σ





∫σ

 

−z 

−

−

dz





Where: t is the total shell thickness, z is the thickness location where the in-plane stress is evaluated.

Note Make sure that the Output Control, General Miscellaneous is set to Yes or your results may be under-defined.

Stabilization Energy Stabilization can help with convergence problems, but it can also affect accuracy if the stabilization energy or forces are too large. Although ANSYS automatically reports the stabilization force norms and compares them to internal force norms, it is still very important to check the stabilization energy and forces to determine whether or not they are excessive. If the stabilization energy is much less than the potential energy (for example, within a 1.0 percent tolerance), the result should be acceptable. Stabilization energy is not available to the Samcef solver. When stabilization energy is large, check the stabilization forces at each DOF for all substeps. If the stabilization forces are much smaller than the applied loads and reaction forces (for example, within a 0.5 percent tolerance), the results are still acceptable. Such a case could occur when an elastic system is loaded first, then unloaded significantly. It is possible that the final element potential energy is small Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Results and stabilization energy is relatively large, but all stabilization forces are small. Currently, stabilization forces are accessible in the .OUT file. Even when both stabilization energy and forces are too large, the results could still be valid. Such a scenario is possible when a large part of an elastic structure undergoes large rigid body motion (as in a snap-through simulation). In such a case, the stabilization energy could be large as well as the stabilization force for some DOFs at some substeps, but the results could still be acceptably accurate. Nevertheless, consider the results along with other support data and use your own discretion. To insert a Stabilization Energy result, highlight the Solution object in the tree, then select Stabilization Energy from the Solution Context Toolbar (p. 59) or right-mouse click on the object and choose Insert> Energy> Stabilization Energy. The following figure shows an example stabilization energy contour plot:

Strain Energy Energy stored in bodies due to deformation. This value is computed from stress and strain results. It includes plastic strain energy as a result of material plasticity. To insert a Stabilization Energy result, highlight the Solution object in the tree, then select Stabilization Energy from the Solution Context Toolbar (p. 59) or right-mouse click on the object and choose Insert> Energy> Strain Energy.

Linearized Stress The Linearized Stress results calculate membrane, bending, peak, and total stress along a straight line path in the Mechanical application. To calculate linearized stress, you must first define a straight line path object using Construction Geometry under Model. A path you define for linearized stress can be of type Two Points or of type X axis Intersection and should have at least 47 sample points. The number of points must be an odd number; otherwise the result will not solve and an error message will be issued. The path must be straight and entirely within the model’s elements. The X axis Intersection option is recommend as it ensures that the start and end points are inside the mesh and that the path is straight. Note that the Two Points method obtains the points from the tessellation of the geometric model, and if the geometry faces are curved, the points might not be inside the mesh. For these

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Structural Results situations, you can use the Snap to mesh nodes feature (see Path (Construction Geometry) (p. 453)) to ensure that the two points are contained within the mesh. Linearized stress does not support the Edge path type. To calculate linearized stresses: 1.

In the object tree, select Solution to make the Solution toolbar available.

2.

On the Solution toolbar, click Linearized Stress, and then click the stress you want to calculate.

3.

In the Details view, select the Path you have defined to calculate the linearized stress.

4.

Select the coordinate system you have used for the model.

5.

Click Solve to calculate linearized stress along the path.

Geometry

Select bodies that contribute toward stress calculation

Path

The path you define to calculate the linearized stresses

Type

Types of linearized stresses available

Coordinate System

Coordinate systems you can select for stress calculation

About Linearized Stress When the result is evaluated, component stress values at the path points are interpolated from the appropriate element’s average corner nodal values. Stress components through the section are linearized by a line integral method and are separated into constant membrane stresses, bending stresses varying linearly between end points, and peak stresses (defined as the difference between the actual (total) stress and the membrane plus bending combination). The Details view shows Membrane, Bending, Membrane + Bending, Peak, and Total stresses. The bending stresses are calculated such that the neutral axis is at the midpoint of the path. Principal stresses are recalculated from the component stresses and are invariant with the coordinate system as long as stress is in the same direction at all points along the defined path. It is generally recommended that calculations be performed in a rectangular coordinate system (e.g. global Cartesian). The Details view also includes the following three choices for 2D Behavior: Planar, Axisymmetric Straight, and Axisymmetric Curve. These choices are available to any type of geometry (for example, you can choose Axisymmetric Straight for a 3D model). For Axisymmetric Straight and Axisymmetric Curve, the Details view includes entries for Average Radius of Curvature and Through-Thickness Bending Stress. The Average Radius of Curvature represents the in-plane (X-Y) average radius of curvature of the inside and outside surfaces of an axisymmetric section. If the radius is zero, a plane or 3D structure is assumed. The curve radius is in the current units. An Axisymmetric Straight analysis always has an infinite radius of curvature (which is denoted by a value of -1). The choices for Through-Thickness Bending Stress are: • Include: Include the thickness-direction bending stresses. • Ignore: Ignore the thickness-direction bending stresses. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Results • Include Using Y Dir. Formula: Include the thickness-direction bending stress using the same formula as the Y (axial direction ) bending stress. Also use the same formula for the shear stress. If the Average Radius of Curvature is non-zero, Mechanical reports the linearized stresses in the section coordinates (SX – along the path, SY – normal to the path, and SZ – hoop direction). In this case, the choice of Coordinate System in the Details view is ignored. If the Average Radius of Curvature is zero, Mechanical reports the linearized stresses in the active results coordinate system.

Notes on Linearized Stress • The line integral method is the same as that used in the Mechanical APDL command PRSECT, RHO, KBR. • Mechanical does not support the Solution Coordinate System for this result. • The Worksheet reports the linearized component and principal stresses for each stress category at the beginning, mid-length, and end of the section path.

Damage Results Mechanical supports a number of damage results using non-linear material models, including the Mullins Effect, Progressive Damage, and Physical Failure Criteria.

Mullins Effect The Mullins effect is a phenomenon resulting from load-induced changes to constitutive response exhibited by some hyper elastic materials, especially filled polymers. The effect is most evident during cyclic loading, where the unloading response is more compliant than the loading behavior. During the process of cyclic loading, stress-strain curve for these materials is dependent on the maximum previous load, where the load is the strain energy of the virgin hyper elastic material. As the maximum previous load increases, changes to the virgin hyper elastic constitutive model also increase, due to the Mullins effect. Below the maximum previous load, the Mullins effect changes are not evolving; however, the Mullins effect still modifies the hyper elastic constitutive response based on the maximum previous load. If the load increases beyond the maximum previous all time value, the result is an irreversible and instantaneous softening of the material, which causes a hysteresis in the stress-strain response. The Mullins effect is modeled with the modified Ogden-Roxburgh pseudo-elastic model (TB,CDM,,,,PSE2) and is applicable to any nearly or purely incompressible hyperelastic model (TB,HYPER). For more information on the Mullins effect, see Mullins Effect Material Model. Mechanical supports two results for the Mullins Effect: Mullins Damage Variable and Mullins Max. Previous Strain Energy. The Mullins Damage Variable is a unitless scale range from 0, at which the material is completely damaged without any stiffness, to 1, at which the material is intact, without any loss of stiffness. At a given time step, the Mullins Max. Previous Strain Energy result is the maximum value of strain energy of the virgin material in the time interval [0, t0], where t0 is the beginning of a time step. Depending on the unit system you choose, this result chooses the appropriate unit of energy. A typical unit is the Joules (J) unit.

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Structural Results

Progressive Damage Progressive Damage is associated with the damage phenomenon that occurs in composite materials. When a composite material is subjected to loading, the matrix and fiber controlled types of failure can occur both separately or sequentially. After a certain point, the material experiences enough damage in the form of the local failures that the material can no longer sustain the load. These local failures govern the ultimate load that the material can withstand. Progressive Damage uses material damage initiation (TB, DMGI) and evolution criteria (TB, DMGE) to analyze the progressive damage in composites. While Physical Failure Criteria analyzes the failure criteria, Progressive Damage analyzes the progression of the damage. Damage Initiation Criteria defines the criteria type for determining the onset of material damage under loading. Depending upon the failure mode selected here, the respective failure criteria will be computed for “Physical Failure Criteria”. The available failure modes for damage are: • Maximum Strain • Maximum Stress • Puck • Hashin • LaRc03 • LaRc04 The Damage Evolution Law defines the material damage evolution law (or the way a material degrades) following the initiation of damage. The stiffness reduction takes a value of 0 to 1, where 0 is no damage and 1 is completely damaged. For more information, see Damage Evolution Law and Damage Initiation Criteria in the Mechanical APDL documentation. The Progressive Damage model supports the following results: Result

Description

Damage Status

The Damage Status result will be an enum type with values of 0, 1, or 2, where • 0 — undamaged • 1 — partially damaged • 2 — completely damaged

Fiber Tensile Damage Variable

The Fiber Tensile Damage Variable result value will be in the range of 0 to the “Tensile Fiber Stiffness Reduction” value set in the Damage Evolution Law. In other words, if you set the Tensile Fiber Stiffness Reduction to 0.6, the range of Fiber Tensile damage variable result will be in the range of 0 to 0.6.

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Using Results Result

Description A value of 0 for this result means undamaged and a value of 1 means completely damaged. The result has no units.

Fiber Compressive Damage Variable

The Fiber Compressive Damage Variable result value will be in the range of 0 to the “Compressive Fiber Stiffness Reduction” value set in the Damage Evolution Law. In other words, if you set the Compressive Fiber Stiffness Reduction to 0.6, the range of Fiber Tensile damage variable result will be in the range of 0 to 0.6. A value of 0 for this result means undamaged and a value of 1 means completely damaged. The result has no units.

Matrix Tensile Damage Variable

The Matrix Tensile Damage Variable result value will be in the range of 0 to the “Tensile Matrix Stiffness Reduction” value set in the Damage Evolution Law i.e. if you set the Tensile Matrix Stiffness Reduction to 0.6, the range of Fiber Tensile damage variable result will be in the range of 0 to 0.6. A value of 0 for this result means undamaged and a value of 1 means completely damaged. The result has no units.

Matrix Compressive Damage Variable

The Matrix Compressive Damage Variable result value will be in the range of 0 to the “Compressive Fiber Stiffness Reduction” value set in the Damage Evolution Law i.e. if you set the Compressive Fiber Stiffness Reduction to 0.6, the range of Fiber Tensile damage variable result will be in the range of 0 to 0.6. A value of 0 for this result means undamaged and a value of 1 means completely damaged. The result has no units.

Shear Damage Variable

The Shear Damage Variable result value will be in the range of 0 to 1. This value is computed using the results of Fiber Tensile Damage Variable, Fiber Compressive Damage Variable, Matrix Tensile Damage Variable, and Matrix Compressive Damage Variable. The result has no units.

Energy Dissipated Per Volume

The Energy Dissipated Per Volume result value will be a positive real number. This result uses a unit of “Energy/Volume” in the unit system you choose.

Physical Failure Criteria The respective failure criteria are computed for the failure modes chosen in the damage initiation criteria. While the damage variables give you an idea where the damage is located and its likely direction of propagation, the Physical Failure Criteria helps you determine how much more load the material can handle. These failure criteria are computed based on the parameters given using the material damage initiation (TB, DMGI) and evolution criteria (TB, DMGE). For more information, see Progressive Damage (p. 893), above, as well as Damage Evolution Law, Damage Initiation Criteria, and Physical Failure Criteria in the Mechanical APDL documentation. The Physical Failure Criteria model supports the following results:

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Structural Results Result

Description

Max Failure Criteria

The Max Failure Criteria is computed based on the maximum of Fiber Tensile Failure Criterion, Fiber Compressive Failure Criterion, Matrix Tensile Failure Criterion, and Mattrix Compressive Failure Criterion.

Fiber Tensile Failure Criterion

The Fiber Tensile Failure Criterion result value will be a positive integer. A value of 0 indicates no failure, while 1 is a complete failure. A value above 1 indicates the material has completely failed. The higher this number, the higher the load above the prescribed limits, although specifics are dependent on the stress limits you set and the amount of loading applied.

Fiber Compressive Failure Criterion

The Fiber Compressive Failure Criterion result value will be a positive integer. A value of 0 indicates no failure, while 1 is a complete failure. A value above 1 indicates the material has completely failed. The higher this number, the higher the load above the prescribed limits, although specifics are dependent on the stress limits you set and the amount of loading applied.

Matrix Tensile Failure Criterion

The Matrix Tensile Failure Criterion result value will be a positive integer. A value of 0 indicates no failure, while 1 is a complete failure. A value above 1 indicates the material has completely failed. The higher this number, the higher the load above the prescribed limits, although specifics are dependent on the stress limits you set and the amount of loading applied.

Matrix Compressive Failure Criterion

The Matrix Compressive Failure Criterion result value will be a positive integer. A value of 0 indicates no failure, while 1 is a complete failure. A value above 1 indicates the material has completely failed. The higher this number, the higher the load above the prescribed limits, although specifics are dependent on the stress limits you set and the amount of loading applied.

Contact Results If your model contains Contact Regions, you can define the contact results as listed below under the Solution object by inserting a Contact Tool. See the Reviewing the Results section of the Contact Technology Guide for additional information. • Gap • Penetration • Pressure • Frictional Stress — available only for evaluating contact conditions after solution.

Note – To reflect total contact pressures or frictional stress, you must either set the Behavior option to Asymmetric or Auto Asymmetric, or manually create an asymmetric contact pair. – For node-to-surface contact, Pressure will display zero results. To display the associated contact force, you must insert a user defined result called CONTFORC.

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Using Results • Sliding Distance — available only for evaluating contact conditions after solution. The total sliding distance (SLIDE) is the amplitude of total accumulated slip increments (a geometrical measurement) when the contact status is sticking or sliding (STAT = 2, 3). It contains contributions from the elastic slip and the frictional slip. Elastic slip due to sticking represents the reversible tangential motion from the point of zero tangential stresses. Ideally, the equivalent elastic slip does not exceed the user-defined absolute limit. The higher the tangent stiffness, the smaller the resulting elastic slip. The pair-based elastic slip can be monitored using the Contact Result Tracker (p. 1052). • Fluid Pressure — Fluid penetration pressure (surface-to-surface contact only). Note that command snippets are required to apply the loading to create this result. For more information, see Applying Fluid PressurePenetration Loads in the Mechanical APDL Contact Technology Guide. • Status. Status codes include: – -3 — MPC bonded contact. – -2 — MPC no-separation contact. – 0 — open and not near contact. – 1 — open but near contact. – 2 — closed and sliding. – 3 — closed and sticking.

Note MPC-based contact definitions use negative values. They indicate the intentional removal of one or more contact constraints to prevent over-constraint. The labels Far, Near, Sliding, and Sticking are included in the legend for Status.

Note Contact that has been deactivated via Auto Asymmetric behavior will be displayed with a status of Far-Open. Results for deactivated pairs can be suppressed in the Contact Tool by changing Both to either Contact or Target as necessary.

If you choose to display contact results with a display option other than Unaveraged, then Mechanical uses all elements in the selected regions to calculate the result. That is, Mechanical averages contact across regions regardless of whether you scoped the result via Geometry Selection or via the Worksheet. For example, if you set the display option to Averaged, then the displayed result for a node is the average of all values (from all selected elements) at that node. Contact elements can be coincident, which may be difficult to discern visually, and Mechanical does not display unaveraged contact results if it detects coincident elements in the scoping. However, Mechanical calculates and displays averaged contact results for coincident elements. The images below illustrate how contact results are affected by the different scoping types. The model consists of two blocks contacting a third block.

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Structural Results

Using the Worksheet method, one Contact Tool was scoped to the contact pair on the left, and another one was scoped to the contact pair on the right. This allows you to view the contact results for each contact pair individually. The contact status for the contact pair on the left is shown below.

The contact status for the contact pair on the right is shown below.

A third Contact Tool scoped to the surface of the large block (using the Geometry Selection method) allows you view the contact status averaged over that surface, as shown below.

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Using Results

Note Be aware of the following restrictions regarding contact results: • When a contact result is scoped to a face of an assembly, a contact result may not be obtained in certain cases, especially if the scoped face is not a part of any contact region. • Contour contact results are not reported for 3D edge contact.

Frequency Response and Phase Response Graphs can be either Frequency Response graphs that display how the response varies with frequency or Phase Response plots that show how much a response lags behind the applied loads over a phase period.

Frequency Response The following equations describe how frequency graphs are defined and plotted. Stress and Strain Results The strain result is calculated using the displacement result. Using the Young’s Modulus and strain result, the stress result can be evaluated. Because of this reason, the stress and strain results are in phase with the displacement result. Results displayed on a graph can be scoped using the graphical selection tools (vertex, face, edge, or nodes) or using Named Selections, and can be viewed as a value graphed along a specified frequency range. These include the frequency results for stress, elastic strain, deformation, velocity, or acceleration (frequency only) plotted as a graph. The plot will include all the frequency points at which a solution was obtained. When you generate frequency response results, the default plot (Bode) shows the amplitude and phase angle.

Note Direct graphical node selection requires you to generate the mesh and have the Select Mesh (see Graphics Options Toolbar Help) tool chosen.

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Structural Results Displacement Result The displacement vector on a structure subjected to harmonic loading may be expressed as: EQUATION 1

{

}={

u t

}

u max

e

i

φ

e

i

Ω

The Frequency Response chart for Displacement is calculated by expressing Equation (1) in time domain as follows: EQUATION 2

{

}={



rl

}

Ω − {
g}

Ω

where:  

φ

=  



=  



=

!

φ

2  

2 + 

φ

=

−1 «#$%& «‘(%)

Velocity Result The equation for velocity u can be obtained by taking a time derivative of Equation (1). The frequency response for velocity in time domain is calculated as follows: EQUATION 3

{ɺ } ={ɺ * +

*,-./

}

Ω − {*ɺ03.4}

Ω

where: ɺ

= −Ω ⋅ 5:;8<

ɺ

= Ω ⋅ BCD@E

ɺ

=

56789

=>?@A

F NOP

φɺ

(

ɺ QGHIJ + Fɺ QKLIM

F

)=

−R SɺTUVW

ɺ

SXYVZ

Acceleration Result The equation for acceleration u can be obtained by taking a double time derivative of Equation (1). The frequency response for acceleration in time domain is calculated as follows:

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Using Results EQUATION 4

uɺɺ t = {uɺɺreal }

Ωt − {uɺɺimag}

Ωt

where: ɺɺ
 = −Ω2 ⋅


ɺɺ = Ω ⋅   + ɺɺ ɺɺ x = ɺɺ   φɺɺ

=

ɺɺ −1 

ɺɺ

Optionally, you can plot the following results values for graphs: • Real • Imaginary • Real and Imaginary • Amplitude • Phase Angle You can select any of these from a drop-down list in the Details view for the results. For edges, faces, surface bodies, and multiple vertex selections (which contain multiple nodes), the results can be scoped as minimum, maximum, or average using the Spatial Resolution option. This option is also available for frequency and phase response results scoped on a single vertex.

Note The Spatial Resolution option is especially important for results scoped to a shell vertex, where the default option, Use Average, may yield unexpected results. The Use Minimum and Use Maximum settings of the Spatial Resolution option are based on the amplitude and thus are reported from the location with either the largest or smallest amplitude. The Use Average setting calculates the average by calculating the real and imaginary components separately.

Note You cannot use the Mechanical application convergence capabilities for any results item under a harmonic analysis. Instead, you can first do a convergence study on a modal analysis and reuse the mesh from that analysis. Presented below is an example of a Frequency Response plot:

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Structural Results

The average, minimum, or maximum value can be chosen for selected entities. Stress, Strain, Deformation, Velocity, and Acceleration components vary sinusoidally, so these are the only result types that can be reviewed in this manner. (Note that items such as Principal Stress or Equivalent Stress do not behave in a sinusoidal manner since these are derived quantities.)

Phase Response Similarly, Phase Response plots show the minimum, average, or maximum Stress, Strain, or Deformation for selected graphical entities (vertex, face, edge, or nodes) or a Named Selection. An example of a Phase Response plot is illustrated below.

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Using Results However, unlike Frequency Response plots that show a response amplitude over a frequency range, Phase Response plots show a response over a phase period, so you can determine how much a response lags behind the applied load. The following functions outline the relationships of response amplitude, phase response graphs, and result contours (with associated caveats): Response Amplitude Response Amplitude is defined as the maximum value of the following expression: value = sqrt(real*real + imag*imag) Where real and imag represent all real and imaginary result values from the result file for the selected frequency. Phase Response Graph The graph is the image of the following function, where Sweeping Phase is allowed to vary across a user specified Duration: value = AMPLITUDE * sin(phase)

Note Take caution when comparing the values in the Output column of the Tabular Data for a Phase Response against maximum values of contour displays. Result Contour Drawing contour displays in a Harmonic Response analysis, Mechanical uses the phase specified by the Sweeping Phase property defined by the user to evaluate the expression: value = real*cos(phase) — imag*sin(phase) Where real and imag represent all real and imaginary result values from the result file for the selected frequency. Because the formula for the Phase Response graph differs from the formula for the contour, an Output value for the graph does not necessarily equal a maximum for a contour result at the same frequency. General approach to harmonic analysis postprocessing Generally speaking, you would look at Frequency Response plots at critical regions to ascertain what the frequency of interest may be. In conjunction with Phase Response plots, the phase of interest is also determined. Then, you can request Stress, Strain, or Deformation contour plots to evaluate the response of the entire structure at that frequency and phase of interest.

Creating Contour Result from Frequency Response Results You can use Frequency Response result types (not including Velocity and Acceleration) to generate new result objects of the same type, orientation, frequency. The phase angle of the contour result will be opposite in sign with the same magnitude as the frequency response result type. The sign of the phase in the Sweeping Phase property of the contour result is reversed so that the response amplitude of the frequency response plot for that frequency and phase defined by the Duration property matches with the contour results. To create a Contour Result in a Harmonic Analysis:

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Structural Results 1. Select and right-click on the desired Harmonic result in the solution tree. 2. Choose Create Contour Result.

As illustrated here, you can see how the feature automatically scopes the Type, Orientation, Frequency, and Sweeping Phase.

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Using Results

The Reported Frequency in the Information category is the frequency at which contour results were found and plotted. This frequency can be potentially different from the frequency you requested.

Stress Tools You can insert any of the following stress tools in a Solution object by choosing Stress Tool under Tools in the Solution context toolbar, or by using a right mouse button click on a Solution object and choosing Stress Tool: Maximum Equivalent Stress Safety Tool (p. 905) Maximum Shear Stress Safety Tool (p. 907) Mohr-Coulomb Stress Safety Tool (p. 908) Maximum Tensile Stress Safety Tool (p. 910) After adding a Stress Tool object to the tree, you can change the specific stress tool under Theory in the Details view. The Stress Tools make use of the following material properties: • Tensile Yield Strength • Compressive Yield Strength • Tensile Ultimate Strength 904

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Structural Results • Compressive Ultimate Strength

Safety Tools in the ANSYS Workbench Product The ANSYS Workbench product uses safety tools that are based on four different stress quantities: 1. Equivalent stress (σe). 2. Maximum tensile stress (σ1). 3. Maximum shear stress (τMAX) This uses Mohr’s circle: σ − σ3 τMAX = 1 where: σ1 and σ3 = principal stresses. 4. Mohr-Coulomb stress This theory uses a stress limit based on σ σ +
f σt σcf where: σ = inpu ensile sress limi σ =   o o   

Maximum Equivalent Stress Safety Tool The Maximum Equivalent Stress Safety tool is based on the maximum equivalent stress failure theory for ductile materials, also referred to as the von Mises-Hencky theory, octahedral shear stress theory, or maximum distortion (or shear) energy theory. Of the four failure theories supported by the Mechanical application, this theory is generally considered as the most appropriate for ductile materials such as aluminum, brass and steel. The theory states that a particular combination of principal stresses causes failure if the maximum equivalent stress in a structure equals or exceeds a specific stress limit: σ ≥   Expressing the theory as a design goal: σ  

<

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905

Using Results If failure is defined by material yielding, it follows that the design goal is to limit the maximum equivalent stress to be less than the yield strength of the material: σe y

<

An alternate but less common definition states that fracturing occurs when the maximum equivalent stress reaches or exceeds the ultimate strength of the material: σ u

<

Options Define the stress limit in the Details view under Stress Limit Type. Use either Tensile Yield Per Material, or Tensile Ultimate Per Material, or enter a Custom Value. By default, Stress Limit Type equals Tensile Yield Per Material. Choose a specific result from the Stress Tool context toolbar or by inserting a stress tool result using a right mouse button click on Stress Tool:

Safety Factor s=

lim it

σ

Safety Margin = − =

  − σ

Stress Ratio σ* =

σ 

Notes • The reliability of this failure theory depends on the accuracy of calculated results and the representation of stress risers (peak stresses). Stress risers play an important role if, for example, yielding at local discontinuities (e.g., notches, holes, fillets) and fatigue loading are of concern. If calculated results are suspect, consider the calculated stresses to be nominal stresses, and amplify the nominal stresses by an appropriate stress concentration factor Kt. Values for Kt are available in many strength of materials handbooks. • If fatigue is not a concern, localized yielding will lead to a slight redistribution of stress, and no real failure will occur. According to J. E. Shigley (Mechanical Engineering Design, McGraw-Hill, 1973), «We conclude, then, that yielding in the vicinity of a stress riser is beneficial in improving the strength of a part and that stress-concentration factors need not be employed when the material is ductile and the loads are static.»

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Structural Results • Alternatively, localized yielding is potentially important if the material is marginally ductile, or if low temperatures or other environmental conditions induce brittle behavior. • Yielding of ductile materials may also be important if the yielding is widespread. For example, failure is most often declared if yielding occurs across a complete section. • The proper selection and use of a failure theory relies on your engineering judgment. Refer to engineering texts such as Engineering Considerations of Stress, Strain, and Strength by R. C. Juvinall (McGraw-Hill) and Mechanical Engineering Design by J. E. Shigley (McGraw-Hill) for in-depth discussions on the applied theories.

Maximum Shear Stress Safety Tool The Maximum Shear Stress Safety tool is based on the maximum shear stress failure theory for ductile materials. The theory states that a particular combination of principal stresses causes failure if the Maximum Shear (p. 884) equals or exceeds a specific shear limit: τ

max

≥

lim it

where the limit strength is generally the yield or ultimate strength of the material. In other words, the shear strength of the material is typically defined as a fraction (f < 1) of the yield or ultimate strength:

s

=

s

− =

 

τ

−



In a strict application of the theory, f = 0.5. Expressing the theory as a design goal: τ

<



 

If failure is defined by material yielding, it follows that the design goal is to limit the shear stress to be less than a fraction of the yield strength of the material: τ



<

y

An alternate but less common definition states that fracturing occurs when the shear stress reaches or exceeds a fraction of the ultimate strength of the material: τ



<

u

Options Define the stress limit in the Details view under Stress Limit Type. Use either Tensile Yield Per Material, or Tensile Ultimate Per Material, or enter a Custom Value. By default, Stress Limit Type equals Tensile Yield Per Material. Define coefficient f under Factor in the Details view. By default, the coefficient f equals 0.5.

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907

Using Results Choose a specific result from the Stress Tool context toolbar or by inserting a stress tool result using a right mouse button click on Stress Tool:

Safety Factor s

=

lim it

τmax

Safety Margin =

− =





τ

−

Stress Ratio * τ =

τ

 

Notes • The reliability of this failure theory depends on the accuracy of calculated results and the representation of stress risers (peak stresses). Stress risers play an important role if, for example, yielding at local discontinuities (e.g., notches, holes, fillets) and fatigue loading are of concern. If calculated results are suspect, consider the calculated stresses to be nominal stresses, and amplify the nominal stresses by an appropriate stress concentration factor Kt. Values for Kt are available in many strength of materials handbooks. • If fatigue is not a concern, localized yielding will lead to a slight redistribution of stress, and no real failure will occur. According to J. E. Shigley (Mechanical Engineering Design, McGraw-Hill, 1973), «We conclude, then, that yielding in the vicinity of a stress riser is beneficial in improving the strength of the part and that stress-concentration factors need not be employed when the material is ductile and the loads are static.» • Alternatively, localized yielding is potentially important if the material is marginally ductile, or if low temperatures or other environmental conditions induce brittle behavior. • Yielding of ductile materials may also be important if the yielding is widespread. For example, failure is most often declared if yielding occurs across a complete section. • The proper selection and use of a failure theory relies on your engineering judgment. Refer to engineering texts such as Engineering Considerations of Stress, Strain, and Strength by R. C. Juvinall (McGraw-Hill) and Mechanical Engineering Design by J. E. Shigley (McGraw-Hill) for in-depth discussions on the applied theories.

Mohr-Coulomb Stress Safety Tool The Mohr-Coulomb Stress Safety Tool is based on the Mohr-Coulomb theory for brittle materials, also known as the internal friction theory. The theory states that failure occurs when the combination of the Maximum, Middle, and Minimum Principal (p. 883) equal or exceed their respective stress limits. The theory compares the maximum tensile stress to the material’s tensile limit and the minimum compressive stress to the material’s compressive limit. Expressing the theory as a design goal:

908

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Structural Results σ1 tensile lim it

+

σ3 compressive lim it

<

where σ1 > σ2 > σ3; σ3 and the compressive strength limit assume negative values even though you must actually enter positive values for these quantities. Also, a given term is only used if it includes the correct sign. For example, σ1 must be positive and σ3 must be negative. Otherwise, the invalid term is assumed to be negligible. Note that the Mohr-Coulomb Stress Safety tool evaluates maximum and minimum principal stresses at the same locations. In other words, this tool does not base its calculations on the absolute maximum principal stress and the absolute minimum principal stress occurring (most likely) at two different locations in the body. The tool bases its calculations on the independent distributions of maximum and minimum principal stress. Consequently, this tool provides a distribution of factor or margin of safety throughout the part or assembly. The minimum factor or margin of safety is the minimum value found in this distribution. For common brittle materials such as glass, cast iron, concrete and certain types of hardened steels, the compressive strength is usually much greater than the tensile strength, of which this theory takes direct account. The design goal is to limit the maximum and minimum principal stresses to their ultimate strength values by means of the brittle failure relationship: σ u

+

σ
u

<

An alternative but less common definition compares the greatest principal stresses to the yield strengths of the material: σ y

+

σ y

<

The theory is known to be more accurate than the maximum tensile stress failure theory used in the Maximum Tensile Stress Safety tool, and when properly applied with a reasonable factor of safety the theory is often considered to be conservative.

Options Define the tensile stress limit in the Details view under Tensile Limit Type. Use either Tensile Yield Per Material, or Tensile Ultimate Per Material, or enter a Custom Value. By default, Tensile Limit Type equals Tensile Yield Per Material. Define the compressive stress limit in the Details view under Compressive Limit Type. Use either Comp. Yield Per Material, or Comp. Ultimate Per Material, or enter a Custom Value. By default, Compressive Limit Type equals Comp. Yield Per Material. Choose a specific result from the Stress Tool context toolbar or by inserting a stress tool result using a right mouse button click on Stress Tool:

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Using Results

Safety Factor   σ3 σ1 +  s =  tensile lim it compressive lim it 

−1

Safety Margin   σ σ − = +  
   
    


=

−

−

Stress Ratio σ

σ* =

  

+

σ   

Notes • The use of a yield strength limit with brittle materials is not recommended since most brittle materials do not exhibit a well-defined yield strength. • For ductile and some other types of materials, experiments have shown that brittle failure theories may be inaccurate and unsafe to use. The brittle failure theories may also be inaccurate for certain brittle materials. Potential inaccuracies are of particular concern if the accuracy of calculated answers is suspect. • The reliability of this failure criterion is directly related to treatment of stress risers (peak stresses). For brittle homogeneous materials such as glass, stress risers are very important, and it follows that the calculated stresses should have the highest possible accuracy or significant factors of safety should be expected or employed. If the calculated results are suspect, consider the calculated stresses to be nominal stresses, and amplify the nominal stresses by an appropriate stress concentration factor Kt. Values for Kt are available in many strength of materials handbooks. For brittle nonhomogeneous materials such as gray cast iron, stress risers may be of minimal importance. • If a part or structure is known or suspected to contain cracks, flaws, or is designed with sharp notches or re-entrant corners, a more advanced analysis may be required to confirm its structural integrity. Such discontinuities are known to produce singular (i.e., infinite) elastic stresses; if the possibility exists that the material might behave in a brittle manner, a more rigorous fracture mechanics evaluation needs to be performed. An analyst skilled in fracture analysis can use the Mechanical APDL application to determine fracture mechanics information. • The proper selection and use of a failure theory relies on your engineering judgment. Refer to engineering texts such as Engineering Considerations of Stress, Strain, and Strength by R. C. Juvinall (McGraw-Hill) and Mechanical Engineering Design by J. E. Shigley (McGraw-Hill) for in-depth discussions on the applied theories.

Maximum Tensile Stress Safety Tool The Maximum Tensile Stress Safety tool is based on the maximum tensile stress failure theory for brittle materials.

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Structural Results The theory states that failure occurs when the maximum principal stress equals or exceeds a tensile stress limit. Expressing the theory as a design goal: σ1 lim it

<

The maximum tensile stress failure theory is typically used to predict fracture in brittle materials with static loads. Brittle materials include glass, cast iron, concrete, porcelain and certain hardened steels. The design goal is to limit the greatest principal stress to be less than the material’s ultimate strength in tension: σ u

<

An alternate definition compares the greatest principal stress to the yield strength of the material: σ y

<

For many materials (usually ductile materials), strength in compression and in tension are roughly equal. For brittle materials, the compressive strength is usually much greater than the tensile strength. The Mohr-Coulomb theory used in the Mohr-Coulomb Stress Safety tool is generally regarded as more reliable for a broader range of brittle materials. However, as pointed out by R. C. Juvinall (Engineering Considerations of Stress, Strain, and Strength, McGraw-Hill, 1967), «There is some evidence to support its use with porcelain and concrete. Also, it has been used in the design of guns, as some test results on thick-walled cylinders tend to agree with this theory.»

Options Define the stress limit in the Details view under Stress Limit Type. Use either Tensile Yield Per Material, or Tensile Ultimate Per Material, or enter a Custom Value. By default, Stress Limit Type equals Tensile Yield Per Material. Choose a specific result from the Stress Tool context toolbar or by inserting a stress tool result using a right mouse button click on Stress Tool:

Safety Factor s=

 

σ

Safety Margin = − =

  − σ

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911

Using Results

Stress Ratio σ1* =

σ1 lim it

Notes • The use of a yield strength limit with brittle materials is not recommended since most brittle materials do not exhibit a well-defined yield strength. • For ductile and some other types of materials, experiments have shown that brittle failure theories may be inaccurate and unsafe to use. The brittle failure theories may also be inaccurate for certain brittle materials. Potential inaccuracies are of particular concern if the accuracy of calculated answers is suspect. • The reliability of this failure criterion is directly related to treatment of stress risers (peak stresses). For brittle homogeneous materials such as glass, stress risers are very important, and it follows that the calculated stresses should have the highest possible accuracy or significant factors of safety should be expected or employed. If the calculated results are suspect, consider the calculated stresses to be nominal stresses, and amplify the nominal stresses by an appropriate stress concentration factor Kt. Values for Kt are available in many strength of materials handbooks. For brittle nonhomogeneous materials such as gray cast iron, stress risers may be of minimal importance. • If a part or structure is known or suspected to contain cracks, flaws, or is designed with sharp notches or re-entrant corners, a more advanced analysis may be required to confirm its structural integrity. Such discontinuities are known to produce singular (i.e., infinite) elastic stresses; if the possibility exists that the material might behave in a brittle manner, a more rigorous fracture mechanics evaluation needs to be performed. An analyst skilled in fracture analysis can use the Mechanical APDL application program to determine fracture mechanics information. • The proper selection and use of a failure theory relies on your engineering judgment. Refer to engineering texts such as Engineering Considerations of Stress, Strain, and Strength by R. C. Juvinall (McGraw-Hill) and Mechanical Engineering Design by J. E. Shigley (McGraw-Hill) for in-depth discussions on the applied theories.

Fatigue (Fatigue Tool) See Fatigue Overview.

Fracture Results To review fracture results in Mechanical, you insert a Fracture Tool under the Solution folder, and then add Fracture Results under the Fracture Tool. Fracture Results are of three types: SIFS Results, J-Integral and VCCT Results. Mechanical computes the fracture parameter result based on the type and subtype of the result definition. The type is based on a SIFS, JINT, and VCCT based result. The subtype for SIFS result is the mode of the stress intensity factor, or Mode I (K1), Mode II (K2) or Mode III (K3) of the SIFS result. The subtype for the VCCT based result is Mode I Energy Release rate (G1), Mode II Energy Release rate (G2), Mode III Energy Release rate (G3), and Total Energy Release rate (GT). The JINT result is the mixed mode result, and has no subtype associated with it. For more information about Fracture Results, see: Fracture Tool

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Structural Results Defining a Fracture Result The Active Contour in the Details view indicates the contour number for which the results are shown under the Results parameter. The Graphics window displays the graphical result for the active contour. The “1” in the Graphics window indicates the start of the crack front, while “2” indicates the end of the crack front.

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Using Results

The results are plotted in the Graph window for all contours, starting from the Contour Start value and ending at the Contour End value. The X axis in the Graph window indicates the distance along the crack front. The start of the crack front has a value of zero, and the end of the crack front has the maximum value. The Tabular Data window displays the data points in a table format.

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Structural Results

Fracture Tool The Fracture Tool allows you to group together all of the different types of fracture results associated with one single Crack or Pre-Meshed Crack object defined in the Fracture folder. To define a Fracture Tool: 1.

Select the Solution object in the Tree Outline.

2.

Choose Tools>Fracture Tool from the Solution context toolbar.

Note By default, a Fracture Result of type Mode I Stress Intensity Factor is inserted under the Fracture Tool.

3.

In the Details View, for the Crack option, select the Crack or Pre-Meshed Crack object for which you want to group results.

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915

Using Results 1.

Select the Fracture Tool from the Tree Outline.

2.

From the Fracture Tool context toolbar, select any results you want to add. • SIFS Results>SIFS(K1) inserts a Mode 1 Stress Intensity Factor result. • SIFS Results>SIFS(K2) inserts Mode 2 Stress Intensity Factor result. • SIFS Results>SIFS(K3) inserts Mode 3 Stress Intensity Factor result. • VCCT Results>VCCT(G1) inserts Mode 1 Energy Release Rate result. • VCCT Results>VCCT(G2) inserts Mode 2 Energy Release Rate result. • VCCT Results>VCCT(G3) inserts Mode 3 Energy Release Rate result. • VCCT Results>VCCT(GT) inserts Total Energy Release Rate result. • J-Integral (JINT) inserts a J-Integral result.

Tip In the Details View, you can change the type of fracture result to SIFS, J-Integral(JINT) or VCCT, change the SIFS result subtype to K1, K2 and K3, and change the VCCT result subtype to G1, G2, G3 and GT.

3.

Define each Fracture Result in the Details view. Options specific to fracture results include: • Contour Start: Specifies the first contour number for which the result will be plotted in the graph and displayed in the tabular data. The value must not be greater than the value of Contour End. This option applies only to the SIFS and JINT types of result. • Contour End: Specifies the last contour number for which the result will be plotted in the graph and displayed in the tabular data. The value must not be greater than value of the Solution Contours option specified for the associated crack object. Since the maximum of 10 contours can be plotted in Graph window at one point of time, the difference between Contour End and Contour Start must not be greater than 9. The option applies only to the SIFS and JINT types of result. • Active Contour: Specifies the contour number for which the results are plotted in the Graphics window and are shown in the Details view. By default, it takes the “Last” value which is the contour number specified for Contour End. This option applies only to the SIFS and JINT types of result. For information on other Details view options, see Results and Result Tools (Group) (p. 1385).

Contact Tool The Contact Tool allows you to examine contact conditions on an assembly both before loading, and as part of the final solution to verify the transfer of loads (forces and moments) across the various contact regions. The Contact Tool is an object you can insert under a Connections branch object for examining initial contact conditions, or under a Solution or Solution Combination branch object for examining the effects of contact as part of the solution. The Contact Tool allows you to conveniently scope contact results to a common selection of geometry or contact regions. In this way, all applicable contact results can be investigated at once for a given scoping.

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Structural Results A Contact Tool is scoped to a given topology, and there exist two methods for achieving this: the Worksheet method and the Geometry Selection method. Under the Worksheet method, the Contact Tool is scoped to one or more contact regions. Under the Geometry Selection method, the Contact Tool can be scoped to any geometry on the model. Regardless of the method, the scoping on the tool is applied to all results grouped under it. To use a Contact Tool, prepare a structural analysis for an assembly with contacts. You then use either the Geometry Selection or Worksheet scoping method for results.

Evaluating Initial Contact Conditions Note To calculate initial contact results, the Contact Tool assumes small deflection. This assumption impacts the resulting pinball radius of the scoped contacts if their Pinball Region property is set to Program Controlled. To evaluate initial contact conditions using the Worksheet method: 1.

Insert a Contact Tool in the Connections folder (Contact Tool from the Connections context toolbar, or right mouse button click on Connections, then Insert> Contact Tool). You will see a Contact Tool inserted that includes a default Initial Information object.

2.

In the Details view of the Contact Tool, ensure that Worksheet (the default) is selected in the Scoping Method field. The Worksheet appears. Scoped contact regions are those that are checked in the table.

3.

You can modify your selection of contact regions in the Worksheet using the following procedures: • To add or remove pre-selected groups of contact regions (All Contacts, Nonlinear Contacts, or Linear Contacts), use the drop-down menu and the corresponding buttons. • To add any number of contact regions, you can also drag-drop or copy-paste any number of contact regions from the Connections folder into the Contact Tool in the Tree View. Also, one or more contact regions can be deleted from the Contact Tool worksheet by selecting them in the table and pressing the Delete key. • To change the Contact Side of all contact regions, choose the option in the drop-down menu (Both, Contact, or Target from the drop-down menu and click the Apply button). • To change an individual Contact Side, click in the particular cell and choose Both, Contact, or Target from the drop-down menu.

4.

Add contact result objects of interest under the Contact Tool folder (Contact> Penetration or Gap or Status from the Contact Tool context toolbar, or right mouse button click on Contact Tool, then Insert> Penetration or Gap or Status). The specific contact result objects are inserted.

5.

Obtain the initial contact results using a right mouse button click on the Contact object, or Contact Tool object, or any object under the Contact Tool object, then choosing Generate Initial Contact Results from the context menu. Results are displayed as follows: • When you highlight the Initial Information object, a table appears in the Worksheet that includes initial contact information for the contact regions that you specified in step 2 above. You can display or hide the various columns in the table. The table rows display in various colors that indicate the Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Results detected contact conditions. A brief explanation of each color is provided in the legend that is displayed beneath the table. Copies of the legend explanations are presented below in quotes, followed by more detailed explanations. – Red: «The contact status is open but the type of contact is meant to be closed. This applies to bonded and no separation contact types.» Workbench has detected an open contact Status condition, which is invalid based on the definitions of Bonded and No Separation contact types. It is very likely that the model will not be held together as expected. The geometry of the contact may be too far apart for the closed condition to be satisfied. Review of the Contact Region definition is strongly recommended. – Yellow: «The contact status is open. This may be acceptable.» Workbench has detected an open contact Status condition on a nonlinear contact type, Frictionless, Rough, or Frictional, which is probably acceptable under certain conditions as stated in their descriptions. If the Status is Far Open, the Penetration and the Gap will be set to zero even though the Resulting Pinball is non-zero.

Note Currently, contact results are not saved to results (.rst) file for all contact elements that are outside the pinball region to optimize the file size. Results for far field contact elements were reported as zero in prior releases.

– Orange: «The contact status is closed but has a large amount of gap or penetration. Check penetration and gap compared to pinball and depth.” Workbench has detected that any of the following contact results are greater than 1/2 of the Resulting Pinball, or greater than 1/2 of the Contact Depth: Gap, Penetration, maximum closed Gap, maximum closed Penetration. This could lead to poor results in terms of stiffness of the contacting interface. It is recommended that you alter the geometry to reduce the gap or penetration. – Gray: «Contact is inactive. This can occur for MPC and Normal Lagrange formulations. It can also occur for auto asymmetric behavior.» Refer to the individual descriptions for the MPC and Normal Lagrange formulations, and the description for Auto Asymmetric behavior.

Note The “not applicable” designation, N/A appears in the following locations and situations: • All result columns when the contact pair is inactive (row is gray, or Inactive appears under the Status column). • The Geometric Gap column for Frictionless, Rough, or Frictional contact Types and an Interface Treatment set to Add Offset, Ramped Effects.

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Structural Results • When you highlight any of the contact result objects, the Geometry tab appears and displays the graphical result for the contact regions that you specified in step 2 above. To evaluate initial contact conditions using the Geometry Selection method: 1.

Select one or more bodies that are in contact.

2.

Insert a Contact Tool in the Connections folder (Contact Tool from the Connections context toolbar, or right mouse button click on Connections, then Insert> Contact Tool). You will see a Contact Tool inserted that includes a default Initial Information object.

Note The scoping of the Initial Information object is only available using the Worksheet method. Selecting bodies as in step 1 above has no effect on Initial Information results.

3.

In the Details view of the Contact Tool, select Geometry Selection in the Scoping Method field. The bodies that you selected in step 1 are highlighted in the Geometry tab.

4.

Add contact result objects of interest under the Contact Tool folder (Contact> Penetration or Gap or Status from the Contact Tool context toolbar, or right mouse button click on Contact Tool, then Insert> Penetration or Gap or Status). The specific contact result objects are inserted.

5.

Obtain the initial contact results using a right mouse button click on the Contact object, or Contact Tool object, or any object under the Contact Tool object, then choosing Generate Initial Contact Results from the context menu. When you highlight any of the contact result objects, the Geometry tab appears and displays the graphical result for the bodies that you selected in step 1.

Evaluating Contact Conditions After Solution Note The default method will be the last one that you manually chose in the Scoping Method drop down menu. If you have already selected geometry, the Scoping Method field automatically changes to Geometry Selection. The default however will not change until you manually change the Scoping Method entry. To evaluate contact conditions after solution using the Worksheet method: 1.

Insert a Contact Tool in the Solution folder (Tools> Contact Tool from the Solution context toolbar, or right mouse button click on Solution, then Insert> Contact Tool> Contact Tool). You will see a Contact Tool inserted with a default contact result.

2.

In the Details view, select Worksheet in the Scoping Method field. The Worksheet appears. Scoped contact regions are those that are checked in the table.

3.

You can modify your selection of contact regions in the Worksheet using the following procedures: • To add or remove pre-selected groups of contact regions (All Contacts, Nonlinear Contacts, or Linear Contacts), use the drop-down menu and the corresponding buttons.

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Using Results • To add any number of contact regions, you can also drag-drop or copy-paste any number of contact regions from the Contact folder into the Contact Tool in the Tree View. Also, one or more contact regions can be deleted from the Contact Tool worksheet by selecting them in the table and pressing the Delete key. • To change the Contact Side of all contact regions, choose the option in the drop-down menu (Both, Contact, or Target from the drop-down menu and click the Apply button). • To change an individual Contact Side, click in the particular cell and choose Both, Contact, or Target from the drop-down menu. 4.

Add more contact results as needed in the Contact Tool folder (Contact> [Contact Result, for example, Pressure] from the Contact Tool context toolbar, or right mouse button click on Contact Tool, then Insert> [Contact Result, for example, Pressure]).

5.

Solve database. Upon completion, you will see contact results with the common scoping of the Contact Tool.

To evaluate contact conditions after solution using the Geometry Selection method: 1.

Select one or more bodies that are in contact.

2.

Insert a Contact Tool in the Solution folder (Tools> Contact Tool from the Solution context toolbar, or right mouse button click on Solution, then Insert> Contact Tool> Contact Tool). You will see a Contact Tool inserted with a default contact result. Because you have already selected one or more bodies, Geometry Selection is automatically set in the Scoping Method field within the Details view.

3.

Add more contact results as needed in the Contact Tool folder (Contact> [Contact Result, for example, Pressure] from the Contact Tool context toolbar, or right mouse button click on Contact Tool, then Insert> [Contact Result, for example, Pressure]).

4.

Solve database. Upon completion, you will see contact results with the common scoping of the Contact Tool.

The configuration of the Contact Tool, in particular the location (Solution vs Solution Combination) and the scoping method, affects the availability of results. A Contact Tool in the Solution Combination folder has the limitation that it supports only pressure, frictional stress, penetration and distance.

Contact Tool Initial Information When a Contact Tool is inserted under the Connections object, it includes a default object, Initial Information. This object provides the following information from the Worksheet. • Name: Contact Region name. • Contact Side: Selected contact side, either Contact or Target. • Type: contact type, Bonded, No Separation, Frictionless, Rough, Frictional. • Status: the status of the contact, Open, Closed, Far Open. • Number Contacting: the number of contact or target elements in contact. • Penetration: the resulting penetration.

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Structural Results • Gap: the resulting gap. • Geometric Penetration: the penetration that initially exists between the Contact and Target surfaces. • Geometric Gap: the gap that initially exists between the Contact and Target surfaces. For Frictional or Frictionless contact, this is the minimum gap. For Bonded or No Separation contact, this is the maximum closed gap detected. • Resulting Pinball: user specified or the Mechanical APDL application calculated pinball radius. • Contact Depth: average contact depth of elements. • Normal Stiffness: the calculated maximum normal stiffness value. • Tangential Stiffness: the calculated maximum tangential stiffness value. • Real Constant: the contact Real Constant number. The following table outlines how to interpret the Gap and Penetration columns in the Initial Contact Information when there is a true initial geometric gap at the contact interface. Contact Type

Interface Treatment

Offset

Status

Penetration

Gap

Geometric Penetration

Geometric Gap

Bonded or No Separation

NA

NA

Closed

0

0

0

True Geometric Gap

Bonded or No Separation

NA

NA

Far Open

0

0

0

0

Frictionless, Rough, or Frictional

Add Offset, No Ramping

0

Far Open

0

0

0

0

Frictionless, Rough, or Frictional

Add Offset, Ramped Effects

0

Far Open

0

0

0

NA

Frictionless, Rough, or Frictional

Add Offset, No Ramping

< True Geometric Gap

Near Open

0

True Geometric Gap — Offset

0

True Geometric Gap

Add Offset, Ramped Effects

< True Geometric Gap

Near Open

0

True Geometric Gap — Offset

0

NA

Add Offset, No Ramping

> True Geometric Gap

Closed

Offset True Geometric Gap

0

0

True Geometric Gap

Frictionless, Rough, or Frictional Frictionless, Rough, or Frictional

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Using Results Contact Type

Interface Treatment

Frictionless, Rough, or Frictional

Offset

Add Offset, Ramped Effects

Status

> True Geometric Gap

Penetration

Gap

Offset True Geometric Gap

Closed

0

Geometric Penetration

Geometric Gap

0

NA

The following table outlines how to interpret the Gap and Penetration columns in the Initial Contact Information when there is a true initial geometric penetration at the contact interface. Contact Type

Interface Treatment

Offset

Status

Penetration

Gap

Geometric Penetration

Geometric Gap

Bonded or No Separation

NA

NA

Closed

0

0

True Geometric Penetration

0

Bonded or No Separation

NA

NA

Far Open

0

0

0

0

Closed

Offset + True Geometric Penetration

0

True Geometric Penetration

0

Closed

Offset + True Geometric Penetration

0

True Geometric Penetration

NA

0

| – Offset | — True Geometric Penetration

True Geometric Penetration

0

0

| – Offset | — True Geometric Penetration

True Geometric Penetration

NA

Frictionless, Rough, or Frictional

Add Offset, No Ramping

| Offset | < Geometric Penetration

Frictionless, Rough, or Frictional

Add Offset, Ramped Effects

| Offset | < Geometric Penetration

Frictionless, Rough, or Frictional

Add Offset, No Ramping

| – Offset | > Geometric Penetration

Frictionless, Rough, or Frictional

Add Offset, Ramped Effects

| – Offset | > Geometric Penetration

Near Open

Near Open

Beam Tool You can apply a Beam Tool to any assembly in order to view the linearized stresses on beam bodies. It is customary in beam design to employ components of axial stress that contribute to axial loads and bending in each direction separately. Therefore, the stress outputs (which are linearized stresses) asso-

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Structural Results ciated with beam bodies have been focused toward that design goal. The Beam Tool is not available to the Samcef solver. The Beam Tool is similar to the Contact Tool in that the tool, not the results themselves control the scoping. By default, the scoping is to all beam bodies. You can change the scoping in the Details view, if desired. To insert a Beam Tool, highlight the Solution object then choose Tools> Beam Tool from the Solution context toolbar. Three beam stress results are included under the Beam Tool object: Direct Stress, Minimum Combined Stress, and Maximum Combined Stress. You can add additional beam stress results or deformation results by highlighting the Beam Tool object and choosing the particular result from the Beam Tool context toolbar. As an alternative, you can right mouse button click on the Beam Tool object and, from the context menu, choose Insert> Beam Tool> Stress or Deformation. Presented below are definitions of the beam stress results that are available: • Direct Stress: The stress component due to the axial load encountered in a beam element. • Minimum Bending Stress: From any bending loads a bending moment in both the local Y and Z directions will arise. This leads to the following four bending stresses: Y bending stress on top/bottom and Z bending stress the top/bottom. Minimum Bending Stress is the minimum of these four bending stresses. • Maximum Bending Stress: The maximum of the four bending stresses described under Minimum Bending Stress. • Minimum Combined Stress: The linear combination of the Direct Stress and the Minimum Bending Stress. • Maximum Combined Stress: The linear combination of the Direct Stress and the Maximum Bending Stress.

Caution Be cautious when adding Beam Tool results to the Solutions Combination feature. As stated above, Beam Tool minimum and maximum results can originate from one of four different physical locations. As a result, the application could add solution results from different physical locations together. For this reason, carefully review stress results used with the Solutions Combination feature.

Beam Results Beam results can be applied only to line body edges and are defined as follows in reference to the solution coordinate system of each beam or pipe element: • Axial Force: the force along a beam element axis (X component). • Bending Moment: the moment in the plane perpendicular to the beam element axis (Y and Z components). • Torsional Moment: the moment about the beam element axis (X component). • Shear Force: the force perpendicular to the beam element axis (Y and Z components). • Shear-Moment Diagram: simultaneously illustrates the distribution of shear forces, bending moments and displacements, as a function of arc length along a path consisting of line bodies. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Results To apply a beam result, define a path by using edges, on the line body edges as described in “Defining a Path using an Edge” in Path (Construction Geometry) (p. 453). For Shear-Moment Diagrams, the defined line body edges must be contiguous. Beam results are not available to the Samcef solver.

Note • User Defined Result equivalents of the above results are BEAM_AXIAL_F, BEAM_BENDING_M, BEAM_TORSION_M, and BEAM_SHEAR_F. • An Axial Force display will not include an arrow (that is, a vector). The force consists of only the X component. A positive force denotes tension; a negative force denotes compression. • If a path is coincident with an edge, beam results from scoping to the path may not match beam results from scoping to the edge. The path for beams only allows contributions from beam elements with both endpoints in the path. An edge can allow contributions from elements that have only one node on the edge.

Shear-Moment Diagram A shear-moment diagram is a beam result that you can apply only to paths, which simultaneously illustrates the distribution of shear forces, bending moments and displacements, as a function of arc length along the path consisting of line bodies. These three quantities are included in a shear-moment diagram because they are so closely related. For example, the derivative of the moment is the shear: dM/dx = V(x) You can pre-define the path by selecting a contiguous set of line body edges, then inserting a ShearMoment Diagram object in the tree. Insert from the Beam Results drop down menu on the Solution context toolbar, or by a right-click on the Solution folder and choosing Insert> Beam Results from the context menu. With the Shear-Moment Diagram object highlighted, the Path, Type and Graphics Display settings in the Details view control the curves you can display in the Worksheet or the Graph window. Descriptions are presented below. When the X, Y, or Z component is indicated, they are in the local coordinate system whose X axis is directed instantaneously along the beam. The Y and Z axes can be inspected using an Element Triad result. All Type and Graphics Display directions are referenced to this axis. • Path: The specific path to which the shear-moment diagram is to apply. For ease of use, before inserting the Shear-Moment Diagram object, you can define the path by selecting a contiguous set of line body edges. You can choose to use this path or any other pre-defined paths that you have created for other path results. • Type: The shear-moment diagram to display. Choices are: – Total Shear-Moment Diagram – Directional Shear-Moment Diagram (VY-MZ-UY) – Directional Shear-Moment Diagram (VZ-MZ-UZ) 924

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Structural Results • Graphics Display: Controls which quantity is plotted in the Graph window and reported as Minimum and Maximum values in the Details view. Example in Worksheet:

You can toggle the display of all the Max and Min annotation labels by right-clicking anywhere in the top diagram and choosing Hide/Show Annotation Labels. Example in Graph and Tabular Data Windows:

Example of Tracking Graph with Path Position: When you click anywhere along the Length axis, the vertical bar and length that display corresponds to the position of the + annotation on the path as shown below.

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925

Using Results

Structural Probes The following structural probe types are available. Probe Type

Applicable Analysis Types

Output

Deformation

Static Structural, Transient Structural, Rigid Dynamics, Explicit Dynamics

Deformation: X axis, Y axis, Z axis, Total

Cha ics

Scop flexi or ri bod

Scop by: b ies (sing bod only gid) tion

926

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Structural Results Probe Type

Applicable Analysis Types

Output

Strain

Static Structural, Transient Structural, Explicit Dynamics

Strain: Components, Principals, Normal X, Norma Y, Normal Z, XY Shear, YZ Shear, XZ Shear, Minimum Principal, Middle Principal, Maximum Princip Intensity, Equivalent (von-Mises)

Stress

Static Structural, Transient Structural, Explicit Dynamics

Stress: Components, Principals, Normal X, Norma Y, Normal Z, XY Shear, YZ Shear, XZ Shear, Minimum Principal, Middle Principal, Maximum Princip Intensity, Equivalent (von-Mises)

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Using Results Probe Type

Applicable Analysis Types

Output

Cha ics

any; fault Glob Cart Position

Static Structural, Transient Structural, Rigid Dynamics, Explicit Dynamics

Position: X axis, Y axis , Z axis

Scop rigid bod only

Scop by: b ies, c ordi syste

Orie tion ordi syst any; fault Glob Cart Velocity

Transient Structural, Rigid Dynamics, Explicit Dynamics

Velocity: X axis, Y axis, Z axis

Scop flexi or ri bod

Scop by: b ies (sing bod only gid) ordi syste (rigi bod only ation only tex, edge face

Orie tion ordi syst

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Structural Results Probe Type

Applicable Analysis Types

Output

Angular Velocity

Transient Structural, Rigid Dynamics,

Angular Velocity: X axis, Y axis, Z axis

Acceleration

Transient Structural, Rigid Dynamics, Explicit Dynamics

Acceleration: X axis, Y axis, Z axis

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929

Using Results Probe Type

Applicable Analysis Types

Output

Cha ics

Glob Cart Angular Acceleration

Transient Structural, Rigid Dynamics

Angular Acceleration: X axis, Y axis, Z axis

Scop rigid bod only

Scop by: b ies.

Orie tion ordi syst any; fault Glob Cart Energy

Static Structural, Transient Structural, Rigid Dynamics

For Static Structural and Transient Structural analyses: Kinetic, Strain. For Rigid Dynamics analyses: Kinetic, Potential, External, Total

Scop flexi or ri bod

Scop by:

• Fo en al ic al or fo Po an

• Fo en gi or fo an tia

• Sy on te To

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Structural Results Probe Type

Applicable Analysis Types

Output

Force Reaction2 (p. 935)

Static Structural, Transient Structural, Modal, Harmonic, Random Vibration, Response Spectrum

Force Reaction: X axis, Y axis, Z axis

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931

Using Results Probe Type

Applicable Analysis Types

Output

Cha ics

Vibr and spon Spec trum Moment Reaction2 (p. 935)

Static Structural, Transient Structural, Modal, Harmonic, Random Vibration, Response Spectrum

Moment Reaction: X axis, Y axis, Z axis

Scop flexi bod only can scop a se plan a bo by s cifyi Surf as th Loca Met

Scop by: Bou Con tion tact gion mot

Poin

Beam Mes Con tion Sur-

face

Orie tion ordi syst any Cart defa to G Cart Only Solu Coo

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Structural Results Probe Type

Applicable Analysis Types

Output

Joint

Transient Structural, Rigid Dynamics

See Joint Probes (p. 944)

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933

Using Results Probe Type

Applicable Analysis Types

Output

Cha ics

Sum tion poin way joint Mom Response PSD1 (p. 935)

Random Vibration

X axis, Y axis, and Z axis. Displacement, Stress, Strain, Acceleration, Velocity

Scop flexi bod only

Scop by: l tion and tex.

Orie tion ordi Syst Only Solu Coo ate S tem valid Rand Vibr Spring

Static Structural, Transient Structural, Rigid Dynamics

Elastic Force, Damping Force, Elongation, Velocity

Scop sprin only

Orie tion ordi syst sprin is on Bearing

Static Structural, Transient Structural, Modal, Harmonic Response, Random Vibration, Response Spectrum

Elastic Force 1, Elastic Force 2, Damping Force 1, Damping Force 2, Elongation 1, Elongation 2, Velocity 1, Velocity 2

Scop bear only

Orie tion ordi syst bear

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Structural Results Probe Type

Applicable Analysis Types

Output

Beam

Static Structural, Transient Structural

Axial Force, Torque, Shear Force at I, Shear Force at J, Moment at I, and Moment at J

Bolt Pretension

Static Structural, Transient Structural

Adjustment, Tensile Force

Generalized Plane Strain

2D: Static Structural, Transient Structural

Rotation: X, Y; Moment: X, Y; Fiber Length Change Force

1 — The Response PSD Probe provides an excitation response plot across the frequency domain of an input PSD load. It also evaluates the root mean square (RMS) of a response PSD. It is assumed that the excitations are stationary random processes from the input PSD values. 2 — The Force and Moment Reactions for Mesh Connections are not supported for Modal and Harmonic Response analyses. 3 — Remote Points must be constrained and Beams and Springs must be grounded. 4 — For reactions on cutting planes, you must explicitly select the bodies to be sliced. You cannot apply this to “all bodies.” You then specify for the Extraction detail whether you want to study nodes in front or behind the plane. The probe will only operate on elements cut by the plane (and only nodes on those elements which are on the selected side of the plane).

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935

Using Results

Differences in Probes Applied to Rigid Bodies The following table describes the differences between probes applied to rigid bodies in an Explicit Dynamics analysis, compared to probes applied to rigid bodies in a Static Structural or Transient Structural analysis. Characteristic

Explicit Dynamics Analysis

Static Structural or Transient Structural Analysis

How rigid part is meshed

Meshed with solid element containing multiple nodes.

Meshed as a single element containing a single node.

Centroid of the rigid part

Need not be represented by any node Results at the single node represent in the mesh. The Mechanical application the displacement, velocity, etc. at computes the part centroid by averthe centroid of the part. aging the element centroids. Each element centroid is the average of the element’s nodes.

Display of minimum and Probe applied to rigid body dismaximum results plays both the minimum and maximum results at a given time because there are multiple elements and nodes reporting results.

Probe applied to rigid body does not display both the minimum and maximum results at a given time because there is only one element and one node reporting results.

The position probe represents the sum of the minimum (or maximum) displacement with the average nodal coordinate.

More Information on Probes See the Probes (p. 1001) section for further information. In addition, see the following sections for details on these probe types: Energy (Transient Structural and Rigid Dynamics Analyses) Reactions: Forces and Moments Joint Probes Response PSD Probe Spring Probes Bearing Probes Beam Probes Bolt Pretension Probes Generalized Plain Strain Probes

Energy (Transient Structural and Rigid Dynamics Analyses) A Transient Structural analysis supports the following energy outputs: Strain Energy: Energy stored in bodies due to deformation. This value is computed from stress and strain results. It includes plastic strain energy as a result of material plasticity. Kinetic Energy: Kinetic energy due to the motion of parts in a transient analysis. A Rigid Dynamics analysis supports the following energy outputs:

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Structural Results Kinetic Energy: Kinetic energy due to the motion of parts in a transient analysis is calculated as ½ *mass* velocity2 for translations and ½ *omegaT*Inertia*omega for rotations. Potential Energy: This energy is the sum of the potential energy due to gravity and the elastic energy stored in springs. The potential energy due to gravity is proportional to the height of the body with respect to a reference ground. The reference used in a Rigid Dynamics analysis is the origin of the global coordinate system. Because of this, it is possible to have a negative potential energy (and negative total energy) depending on your model coordinates. The elastic energy includes only energy due to deformation of spring(s) in a rigid body dynamic analysis and is calculated as ½ * Stiffness * elongation2. External Energy: This is all the energy the loads and joints bring to a system. Total Energy: This is the sum of potential, kinetic and external energies in a Rigid Dynamics analysis.

Note Energy results are not available for Rigid Dynamics analysis on a body per-body basis. An energy probe scoped on a body will return the energy of the whole part to which body belongs.

Reactions: Forces and Moments You can obtain reaction forces and moments using Force Reaction probes or Moment Reaction probes. At the solver level, the output of reaction forces and moments is controlled via the MAPDL OUTRES command. Support types marked RSOL are governed by the RSOL option, which refers to nodal constraint reactions. Those marked NLOAD and MISC are governed by the NLOAD and MISC options, which refer to the elemental nodal loads and elemental miscellaneous data, respectively. In addition, some analysis and support types require you turn them on in the Output Controls. If no setting is specified for a reaction type, the output occurs automatically. When you request a Force Reaction or a Moment Reaction in a Cartesian coordinate system at a specific time point by setting Display to Single Time Point in the Details view for Static Structural and Transient Structural Analysis, the Force Reaction or Moment Reaction is displayed by an arrow in the Geometry window. Force Reaction uses a single arrowhead and Moment Reaction uses double arrowhead. The arrows are drawn on the deformed mesh. Similarly, when the force or moment reaction results are requested based on Frequency or Set Number and Phase Angle for Harmonic analysis or Mode Number for Modal analysis, the base of the arrow of the moment probe is placed at the Summation Point (or «centroid»; the simple calculated average; unweighted by length, area, or volume). However, a Moment Reaction probe whose Location Method is a remote point will place the base of the arrow at the location of the remote point. In this case, there is no detail for Summation Point, and Mechanical does not employ a moment arm calculation. The moments are precisely the nodal moments for the remote point in the result file (as printed by the PRRSOL command in Mechanical APDL). For those Moment probes which perform a moment arm calculation, Mechanical employs the undisplaced mesh. In other words, when Mechanical computes a moment arm for a node, it finds the difference between the (x,y,z) of the node and the summation point (sx,sy,sz) in the base mesh: moment_arm = (x,y,z) — (sx,sy,sz) The following sections discuss each type of reaction, the option that controls the output, and any required setting in the Output Controls. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

937

Using Results

Fixed Boundary Conditions For fixed boundary conditions, including: • Face, Edge, and Vertex Rotations (do not include Force reactions) • Displacements for Faces, Edges, and Vertices • Cylindrical Support • Frictionless face • Simply Supported Edge and Vertex • Finite Element (FE) Connection Boundary Conditions (Nodal Displacement and Nodal Rotation) Reaction Type Static Transient Full Modal Harmonic Response Full Harmonic Response Mode-Superposition

Output Controlled By The output of these options are controlled by the RSOL option of the OUTRES command. The output of these options are controlled by the RSOL option of the OUTRES command. To enable the output, set Calculate Reactions = Yes in the Output Controls. If results are expanded from a modal solution, then the output of these options are controlled by both the RSOL and NLOAD options of the OUTRES command. You must set both Calculate Reactions and Nodal Forces to either Yes or Constrained Nodes in the Output Controls.

Note Transient Mode-Superposition

Constrained Nodes is the preferred option, as the results file size will be smaller and the process time shorter. Otherwise, the output of these options are controlled by the RSOL option of the OUTRES command. Set Calculate Reactions = Yes in the Output Controls.

Remote Displacement Reaction Type Static Transient Full Modal

938

Output Controlled By The output of these options are controlled by the RSOL option of the OUTRES command. The output of these options are controlled by the RSOL option of the OUTRES command.

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Structural Results Reaction Type Harmonic Response Full RS

Output Controlled By

To enable the output, set Calculate Reactions = Yes in the Output Controls.

Random Vibration PSD Harmonic Response Mode-Superposition

If results are expanded from a modal solution, then the output of these options are controlled by both the RSOL and NLOAD options of the OUTRES command. You must set both Calculate Reactions and Nodal Forces to either Yes or Constrained Nodes in the Output Controls.

Note Transient Mode-Superposition

Constrained Nodes is the preferred option, as the results file size will be smaller and the process time shorter. Otherwise, the output of these options are controlled by the RSOL option of the OUTRES command. Set Calculate Reactions = Yes in the Output Controls.

Compression Only Support Reaction Type Static Transient Full

Output Controlled By The output of these options are controlled by the RSOL option of the OUTRES command. Reaction probes scoped to a Compression Only boundary condition cannot display results if the solver did not converge.

Elastic Support Reaction Type Static Transient Full

Output Controlled By The output of these options are controlled by the NLOAD option of the OUTRES command. To enable the output, set Nodal Forces = Yes in the Output Controls.

Imported Displacement Reaction Type Static Transient Full

Output Controlled By The output of these options are controlled by the RSOL option of the OUTRES command.

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Using Results

Weak Springs Reaction Type Static Transient Full

Output Controlled By The output of these options are controlled by the RSOL option of the OUTRES command.

Grounded Beam Reaction Type Static Transient Full Modal Harmonic Response Full Harmonic Response Mode-Superposition

Output Controlled By The output of these options are controlled by the RSOL option of the OUTRES command. The output of these options are controlled by the RSOL option of the OUTRES command. To enable the output, set Calculate Reactions = Yes in the Output Controls. If results are expanded from a modal solution, then the output of these options are controlled by both the RSOL and NLOAD options of the OUTRES command. You must set both Calculate Reactions and Nodal Forces to either Yes or Constrained Nodes in the Output Controls.

Note Transient Mode-Superposition

Constrained Nodes is the preferred option, as the results file size will be smaller and the process time shorter. Otherwise, the output of these options are controlled by the RSOL option of the OUTRES command. Set Calculate Reactions = Yes in the Output Controls.

Contact Reaction Type Static

Transient Full

Modal Standalone Harmonic

940

Output Controlled By The underlying element options are controlled by the NLOAD option of the OUTRES command. To enable the output, set Nodal Forces = Yes in the Output Controls. The contact element options are governed by the MISC option of the OUTRES command. To enable the output, set Contact Miscellaneous = Yes in the Output Controls. These analysis types do not support contact reactions using the contact element option. They only support contact reactions using the underlying element option.

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Structural Results Reaction Type

Output Controlled By

Response Full Standalone Harmonic Response Mode-Superposition Harmonic Response Analysis Linked to Modal Analysis

You control the underlying element options using the NLOAD option of the OUTRES command. To enable the output, set the Nodal Forces property to Yes in the Output Controls category.

Transient Linked to Modal Analysis

Remote Point Reaction Type Static Transient Full Modal Harmonic Response Full Harmonic Response Mode-Superposition

Output Controlled By The output of these options are controlled by the RSOL option of the OUTRES command. The output of these options are controlled by the RSOL option of the OUTRES command. To enable the output, set Calculate Reactions = Yes in the Output Controls. If results are expanded from a modal solution, then the output of these options are controlled by both the RSOL and NLOAD options of the OUTRES command. You must set both Calculate Reactions and Nodal Forces to either Yes or Constrained Nodes in the Output Controls.

Note Transient Mode-Superposition

Constrained Nodes is the preferred option, as the results file size will be smaller and the process time shorter. Otherwise, the output of these options are controlled by the RSOL option of the OUTRES command. Set Calculate Reactions = Yes in the Output Controls.

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941

Using Results

Grounded Spring Reaction Type Static Transient Full Modal Harmonic Response Full Harmonic Response Mode-Superposition

Output Controlled By The output of these options are controlled by the RSOL option of the OUTRES command. The output of these options are controlled by the RSOL option of the OUTRES command. To enable the output, set Calculate Reactions = Yes in the Output Controls. If results are expanded from a modal solution, then the output of these options are controlled by both the RSOL and NLOAD options of the OUTRES command. You must set both Calculate Reactions and Nodal Forces to either Yes or Constrained Nodes in the Output Controls.

Note Constrained Nodes is the preferred option, as the results file size will be smaller and the process time shorter.

Transient Mode-Superposition

Otherwise, the output of these options are controlled by the RSOL option of the OUTRES command. Set Calculate Reactions = Yes in the Output Controls.

Mesh Connection Reaction Type

Output Controlled By

Static Transient Full Modal Transient Mode-Superposition

The output of these options are controlled by the NLOAD option of the OUTRES command. To enable the output, set Nodal Forces = Yes in the Output Controls.

Surface Reaction Type

Output Controlled By

Static Transient Full

The output of these options are controlled by the NLOAD option of the OUTRES command.

Transient Mode-Superposi- To enable the output, set Nodal Forces = Yes in the Output Controls. tion

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Structural Results

Support Requirements and Limitations • Force Reaction probes support Cartesian or cylindrical coordinate systems. Moment Reaction probes support Cartesian coordinate systems only. • A Moment Reaction probe cannot be scoped to a Grounded Spring. • A reported reaction may be inappropriate if that support shares a face, edge, or vertex with another support, contact pair, or load. This is because the underlying finite element model will have both loads and supports applied to the same nodes. If a model contains two or more supports that share an edge or vertex, use caution in evaluating the listed reaction forces at those supports. Calculation of reaction forces includes the force acting along bounding edges and vertices. When supports share edges or vertices the global summation of forces may not appear to balance. Reaction forces may be incorrect if they share an edge or face with a contact region. • For a Moment Reaction scoped to a contact region, the location of the summation point may not be exactly on the contact region itself. • If you set Extraction = Contact (Underlying Element) in the Details view of either a Force Reaction or Moment Reaction probe, the reaction calculations work from summing the internal forces on the underlying elements under a contact region. Thus, a reported reaction may be inappropriate on a contact face if that face shares topology with another contact face/edge or external load (such as a force or fixed support), which would contribute to the underlying elements’ internal force balance. In addition, during a Transient analysis, inertial and damping forces are also included. Another possible scenario could arise for MPC contact of solid surfaces. In this case, if a gap is detected, the solver may build constraints on an additional layer into the solid mesh from the TARGET elements. This produces a more accurate response but will invalidate any reactions from the underlying solid elements of the TARGET elements. If symmetric contact is chosen be careful to verify which side becomes active for the TARGET elements so that the correct reaction can be determined. • For Modal analysis, reaction results in damped modal analysis provide a By field option in the result definition to compute results based on Mode Number, Phase of Maximum, and Maximum Over Phase. • For Harmonic analysis, reaction results support all options of the result definition available for other harmonic results, and are reported based on the nearest frequency results available; no interpolation is done. • Reaction results sweep through a phase period of 0o and 360o at a specified increment. In previous releases of Mechanical (14.5 and earlier), the default value for this increment was 1o in order to determine the Phase of Maximum and the Maximum Over Phase values. For Harmonic Response analyses only, the phase increment can be controlled using the Phase Increment option. A Phase Increment entry can be between 1o and 10o. The default Phase Increment value is 10o but for legacy database results it is 1o. • For Random Vibration and Response Spectrum analysis, reaction results can only be scoped to a Remote Displacement boundary condition. Animation of reaction results is not supported for modal and harmonic analysis. • Since Beam Connections are, by definition, three dimensional in nature, the reactions object scoped to grounded beams may produce reactions in all three directions/axis for two dimensional analysis. The Tabular Data view will reflect the reactions in all three axes, while the Results view will only reflect values in two axis. The total reactions will be calculated taking into account the reaction components in all three axis. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

943

Using Results • For a force reaction scoped to a contact region, if you set Extraction = Contact (Contact Element), the reaction calculations come directly from the contact elements themselves. This results in accurate force reactions even when the contact region overlaps with other boundary conditions, such as other contact regions, supports, etc. Characteristics of the Contact (Contact Element) setting are that MPC contact is not supported, nor are reactions from the Target (Underlying Element) side. This feature should only be used with Asymmetric contact and requires that Contact Miscellaneous be set to Yes in the Output Controls. A limitation of the Contact (Contact Element) setting is when you use linear contact (that is, either Bonded or No Separation contact types) with loads that are unrealistically very high or very low in magnitude. These situations can produce inaccurate force reactions. • When a probe is scoped to a Mesh Connection, the Mechanical application reports the following reactions: – Forces and Moments summed from the element nodal forces and moments in the result file. – The Extraction detail determines which elements (Master or Slave) contribute to the force or moment sum. • The Surface probe type enables you to study reactions on cutting planes. You can extract generated member forces and reactions through a model by using a reaction probe scoped to a surface. For this probe type, you must explicitly select the bodies to be sliced. You cannot apply this to “all bodies.” You then specify for the Extraction detail whether you want to study nodes in front or behind the plane. The probe operates on elements cut by the plane (and only nodes on those elements which are on the selected side of the plane). Currently, surface probes cannot intersect a plane strain or an axisymmetric model and consequently no results display for this scoping.

Joint Probes The joint type determines the available result types. Refer to the Joint Types (p. 545) section for a discussion of joint types and the free degrees of freedom. The following table presents each of the joint probe results available through the Result Type drop down menu in the Details view. Joint Probe Result Type

Applicable Joint Type(s)

Total Force

All

Total Moment

All except Slot and Spherical

Relative Displacement

All except Revolute, Universal, and Spherical

Relative Velocity

All except Revolute, Universal, and Spherical

Relative Acceleration

All except Revolute, Universal, and Spherical

Relative Rotation

All except Translational

Relative Angular Velocity

All except Translational

Relative Angular Acceleration

All except Translational

Damping Force

Bushing

Damping Moment

Revolute, Cylindrical, and Bushing

Constraint Force

Revolute, Cylindrical, and Bushing

Constraint Moment

Revolute, Cylindrical, and Bushing

Elastic Moment

Revolute, Cylindrical, and Bushing

Elastic Force

Bushing

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Structural Results

Joint Probe Characteristics and Requirements Review the following characteristics and requirements to ensure that you properly configure your result. • A joint defines the interface between two bodies. One of the bodies is referred to as a Reference body and the other as the Mobile body. The results from the joint measure the relative motion of the mobile body with respect to the reference body. • A joint definition also includes specification of a local “reference” coordinate system for that joint. All results from the joint are output in this reference coordinate system. • The reference coordinate system moves with the reference body. Depending on the motion of the reference body it might be difficult to interpret the joint results. • All of these results have X, Y, and Z components in the reference coordinate system. • Relative rotation is expressed in Euler angles. When all three rotations are free, the general joint cannot report an angle that accounts for the number of turns. A typical behavior will be to switch from +π radians to -π radians for increasing angles passing the π limit, as illustrated below.

• For spherical and general joints the output of relative rotations is characterized by the Cardan (or Bryant) angles; the rotation around the joint Y axis is limited to between -90 degrees to +90 degrees. When this rotation magnitude value reaches 90 degrees, the output may “jump” to the opposite sign. • The convention for the deformations differs for joints in a Rigid Dynamics analysis vs. those in a Transient Structural analysis. For the Rigid Dynamics type, the reference of zero deformation is taken after the model has been assembled, and the initial conditions have been applied. For the Transient Structural analysis type, the initial location of bodies is used as reference, before applying initial conditions. • When you request a force or moment at a specific time point by setting Display time = time value in the Details view of a Joint probe, the force or moment will be displayed by an arrow in the Geometry window. Force will use a single arrowhead and moment will use double arrowhead. • Joints compute no reactions forces or moments for the free degrees of freedom of the joint. However, Displacement, Velocity, Acceleration, Rotation, Rotational Velocity and Rotational Acceleration conditions — generate forces and moments, that are reported in the constraint force and moment. • Joint forces and moment conditions are not reported in the joint force and moment probe. • Joint force and moment are by definition the action of the moving body on the reference body. For the ANSYS solver, the joint constraint forces and moments are reported in the joint reference coordinate system. The elastic forces/moments and damping forces/moments in the joints are reported in the reference and mobile axes of the joint which follow the displacements and rotations of the underlying nodes of the joint element. When using the ANSYS Rigid Dynamics solver, the joint forces and moments components are always reported in the joint reference coordinate system.

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945

Using Results • Joint force and moment probes are not supported for Body-Body fixed joints that are scoped to rigid bodies in analyses that use the MAPDL solver. If these outputs are important, consider using a general joint.

Response PSD Probe The Response PSD Probe provides a spectrum response of a structural component subjected to a random excitation. Response PSD is plotted as square of spectrum response over excitation frequency range. The plot provides an information as to where the average power is distributed as a function of frequency. The square root of the area under the response PSD is the so-called root-mean-square (RMS) value. It is a one-sigma, or one-standard-deviation, value in a statistical term. The Details View properties and selections for the Response PSD object are described below. Property

Control

Description

Definition

Type

Read-only control — only Response PSD is allowed for this result.

Location Method

The response PSD is a point based result. The location of the point can be provided using geometry selection or coordinate system. For the geometry selection, only vertex is allowed for the selection. For the coordinate system, a local/customized coordinate system defining a certain location can be used for evaluation of the response PSD. It can also be scoped to a Remote Point if there is one defined in geometry.

Geometry

Appears if Scoping Method is set to Geometry Selection.

Orientation

Read-only control — only Solution Coordinate System is allowed for this result.

Location

Appears if Location Method is set to Coordinate System.

X Coordinate

Read-only field that displays coordinate that is based on the Location property of the coordinate system.

Y Coordinate

Read-only field that displays coordinate that is based on the Location property of the coordinate system.

Z Coordinate

Read-only field that displays coordinate that is based on the Location property of the coordinate system.

Reference

Two options are available for the response PSD result evaluation; Relative to base motion (or relative motion) and Absolute (including base motion). For the Relative to base motion, the response of any location in a structural component is calculated in term of a relative motion between the base and the structural component, and vice versa.

Remote Points

Appears if Location Method is set to Remote Points.

Suppressed

Include (No) or exclude (Yes) the result in the analysis.

Result Type

Result Type: The result types include three basic motion characteristics (Displacement, Velocity and Acceleration), Stress (including normal and shear) and Strain (including normal and shear).

Result Selection

Defines the direction, in Solution Coordinate System, in which response specified in the result type is calculated.

RMS Value

Read-only field that displays value calculated during solution.

Options

Results

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Structural Results

Spring Probes You can use a probe to display the following longitudinal result items from a spring. Elastic Force: The force is calculated as (Spring Stiffness * Elongation). The force acts along the length of the spring. Damping Force: Damping force is calculated as (Damping Factor * velocity) and acts to resist motion. Elongation: The elongation is the relative displacement between the two ends of the springs. The elongation could be positive (stretching the spring) or negative (compressing the spring). Velocity: Velocity is the rate of stretch (or compression) of the spring. This quantity is only calculated in a Transient Structural or Rigid Dynamics analysis.

Bearing Probes A Bearing is essentially a two-spring-damper system that is aligned in any two coordinate axes of a coordinate system; primarily a rotating plane. For rotations in the X-Y plane, the result items for the first axis are in X direction and the results for the second axis are in Y direction. The application adds a suffix (number 1 and 2) to each result item. The X-Z and Y-Z rotation planes also use this convention. You can use a Bearing probe to display the following result items. Elastic Force 1 The force is calculated as (Spring Stiffness * Elongation). The force acts along the length of the spring along the first axis. Elastic Force 2 The force is calculated as (Spring Stiffness * Elongation). The force acts along the length of the spring along the second axis. Damping Force 1 Damping force is calculated as (Damping Factor * Velocity) and acts to resist motion along the first axis. Damping Force 2 Damping force is calculated as (Damping Factor * Velocity) and acts to resist motion along the second axis. Elongation 1 The elongation is the relative displacement between the two ends of the spring in the first axis. The elongation could be positive (stretching the spring) or negative (compressing the spring). Elongation 2 The elongation is the relative displacement between the two ends of the spring in the second axis. The elongation could be positive (stretching the spring) or negative (compressing the spring). Velocity 1 Velocity is the rate of stretch (or compression) of the spring in the first axis. This quantity is only calculated in a Transient Structural analysis. Velocity 2 Velocity is the rate of stretch (or compression) of the spring in the second axis. This quantity is only calculated in a Transient Structural analysis.

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Using Results

Beam Probes The Beam Probe results provide you the forces and moments in the beam from your analysis. Using the Beam Probe you can determine the Axial Force, Torque, Shear Force at I, Shear Force at J, Moment at I, Moment at J. You can also add the Force reaction and Moment Reaction probes to view reaction force moment for the beam. To add beam probes: 1.

In the Project Tree, click Solution to make the Solution toolbar available.

2.

On the Solution toolbar, click Probe, and then click Beam to add the Beam Probe under Solution.

3.

In the Details view, under Definition, click the Boundary Condition list and click the beam you want to analyze.

4.

Under Options, in the Result Selection list, click the result you want to calculate.

Bolt Pretension Probes When a Bolt Pretension load is applied, the Mechanical application reports the following reactions: Adjustment: This represents the displacement that occurs from the pretension. In Mechanical APDL terms, this is the displacement reported from the pretension node. This result is also available for reporting regardless of how the bolt is defined. Working Load: This represents a constrained force reaction from the pretension load. In Mechanical APDL terms, this is the constrained reaction reported from the pretension node. This is essentially the sum of all the forces acting through the pretension cut. This result is applicable for load steps when the load is defined by either Locked or Adjustment or Increment.

Generalized Plain Strain Probes When a Generalized Plane Strain load is applied (2D application), the Mechanical application reports the following reactions: • Fiber Length Change: Fiber length change at ending point. • Rotation X Component: Rotation angle of end plane about x-axis. • Rotation Y Component: Rotation angle of end plane about y-axis. • Force: Reaction force at end point. • Moment X Component: Reaction moment on end plane about x-axis. • Moment Y Component: Reaction moment on end plane about y-axis.

Gasket Results Gasket results are structural results associated with ANSYS interface elements. When used with ANSYS structural elements, interface elements simulate an interface between two materials. The behavior at these interfaces is highly nonlinear. To mesh a body using interface elements, highlight the Body object in the tree and set Stiffness Behavior to Gasket.

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Structural Results The following gasket results are available in the Mechanical Application: • Normal Gasket Pressure — corresponding to Mechanical APDL command PLNSOL,GKS,X • Shear Gasket Pressure — corresponding to Mechanical APDL commands PLNSOL,GKS,XY and PLNSOL,GKS,XZ • Normal Gasket Total Closure — corresponding to Mechanical APDL command PLNSOL,GKD,X • Shear Gasket Total Closure — corresponding to Mechanical APDL commands PLNSOL,GKD,XY and PLNSOL,GKD,XZ These results are only available in the solution coordinate system.

Campbell Diagram Chart Results A Campbell diagram chart result is only valid in Modal analyses. The Campbell diagram chart result is mainly used in rotor dynamics for rotating structural component design. When a structural component is rotating, an inertial force is introduced into the system. The dynamic characteristics of the structural component change as a result of the inertia effect, namely, gyroscopic effect. To study changes in dynamic characteristics of a rotating structure, more than one solve point in Rotational Velocity is required.

Prerequisites In addition to being applicable to only Modal analyses, you must ensure that the following Analysis Settings are activated in order to properly apply a Campbell Diagram. Select the Analysis Settings object in your Modal Analysis and perform the following settings: • Under Solver Controls, Damped = On. • Under Rotordynamics Controls: – Coriolis Effect = On – Campbell Diagram = On In addition, a Rotational Velocity boundary condition must be created in order to properly scope the Campbell Diagram.

Applying a Campbell Diagram To insert a Campbell diagram chart result, highlight the Solution object in the tree, then select Campbell Diagram from the Solution Context Toolbar, or right click on the object and choose Insert > Campbell Diagram. The following is an example of a Campbell diagram result chart:

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Using Results

In this chart, each line represents a frequency evolution of a whirl mode with respect to increased rotational velocities. The whirl frequency value of an eigenmode at each rotational velocity is also listed in the table. For each whirl mode, it is either labeled as forward (FW) or backward (BW) whirl direction. In some cases, when there is no evident whirl direction, the whirl frequency is labeled as UNDETERMINED. If a whirl mode is identified as FW, the rotating structural component whirls the same direction as the rotation direction, and vice versa. If a whirl mode is evaluated to be unstable (marked as UNSTABLE), the whirl orbit will evolve into a divergent trajectory, instead of an elliptical trajectory. In addition to whirl modes, a line (black color) of any ratio between whirl frequency and rotational velocity is plotted. The intersection between this line and each whirl mode is indicated with a red triangular marker. The rotational velocity corresponding to this intersection is called critical speed. At critical speed, the rotating structural component will experience a peak as the rotating frequency resonates with the natural whirl frequency. The Campbell diagram chart result can be customized in Details of Campbell Diagram as follows:

Scope • Rotational Velocity Selection: This field displays the user-defined Rotational Velocity of the analysis for which the Campbell diagram chart result is evaluated. If one is not defined, the field is highlighted in yellow and displays the value None.

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Structural Results

Campbell Diagram Controls • Y Axis Data: There are three data types available for selection; Frequency, Stability and Logarithmic Decrement. The default is Frequency. • Critical Speed: Option for users to display critical speeds. The default is Yes. Requires you to provide a value in the Ratio field. The option is only valid for frequency. • Ratio: Value used to evaluate critical speeds. The default value is 1.0. • Sorting: Option to display data in a sorted mode manner when some modes are crossing/intercepting each other. The default is Yes.

Note Any change made in these fields requires a result re-evaluation.

Axis Note Two different unit types, rad/s and RPM, are available to define rotational velocity in the chart. The selection can be made in Units toolbar. • X Axis Label: Allows users to provide a customized label for rotational velocity. • X Axis Range: There are two options to display the rotational velocity data range; Program Controlled and Specified. The default is Program Controlled, which uses minimum and maximum determined by the system. The option of Specified allows users to provide a customized range to be used in the chart. The minimum and maximum values are displayed in the X Axis Minimum and X Axis Maximum fields below after result evaluation is done. • X Axis Minimum: Minimum rotational velocity value is displayed according to the selection made in X Axis Range. • X Axis Maximum: Maximum rotational velocity value is displayed according to the selection made in X Axis Range. • Y Axis Label: Allows users to provide a customized label for frequency, stability or logarithmic decrement depending on the selection made in Y Axis Data. • Y Axis Range: There are two options, Program Controlled and Specified, to display the frequency, stability or logarithmic value range depending on the selection made in Y Axis Data. The default is Program Controlled, which uses minimum and maximum determined by the system. The option of Specified allows users to provide a customized range to be used in the chart. The minimum and maximum values are displayed in the Y Axis Minimum and Y Axis Maximum fields below after result evaluation is done. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Results • Y Axis Minimum: Minimum frequency, stability or logarithmic decrement value is displayed according to the selection made in Y Axis Range. • Y Axis Maximum: Maximum frequency, stability or logarithmic decrement value is displayed according to the selection made in Y Axis Range.

Thermal Results The following thermal result topics are addressed in this section: Temperature Heat Flux Heat Reaction Error (Thermal) Thermal Probes Thermal Probes (p. 953) can be used to determine the following results: • Temperature • Heat Flux • Heat Reaction

Note Currently, thermal analyses do not support the Contact Tool.

Temperature In a steady-state or transient thermal analysis, temperature distribution throughout the structure is calculated. This is a scalar quantity. Scoping allows you to limit the temperature display to particular geometric entities. Similarly scoping allows you to get reactions at specific boundary condition objects. Temperature results can be displayed as a contour plot. You can also capture the variation of these results with time by using a probe.

Heat Flux The Mechanical application calculates the heat flux (q/A, energy per unit time per unit area) throughout the body. Heat flux can be output as individual vector components X, Y or Z. You can display the X, Y, and Z components of heat flux in different coordinate systems.

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Thermal Results Scoping allows you to limit the heat flux display to particular geometric entities. Similarly scoping allows you to get reactions at specific boundary condition objects. Heat flux results can be displayed as a contour plot. You can also capture the variation of these results with time by using a probe.

Plots of Vector Heat Flux A Vector Heat Flux plot provides the direction of heat flux (relative magnitude and direction of flow) at each point in the body. The following graphic illustrates an example showing a high temperature area at the top and a low temperature area at the bottom. Note the direction of the heat flow as indicated by the arrows.

Request Vector Heat Flux plots in the same way that you would request any other result. After inserting the result object in the tree and solving, click the Graphics button in the Result context toolbar.

Heat Reaction You can obtain heat reaction (q, energy per unit time) at locations where a temperature, imported temperature, convection, or radiation boundary condition is specified. Heat reaction is a scalar. To obtain a heat reaction result, insert a Reaction probe and specify an existing Boundary Condition. See Thermal Probes (p. 953) for more information.

Error (Thermal) The description of this result is the same as Error (Structural) except that heat flux is the basis for the errors instead of stresses.

Thermal Probes The following thermal probe types are available.

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Using Results Probe Type

Applicable Analysis Output Types

Characteristics

Temperature

Steady-state thermal, transient thermal

Temperature: overall

Scope to: body.

Steady-state thermal, transient thermal

Heat Flux: X axis, Y axis, Z axis

Heat Flux

Scope by: bodies, location only, vertex, edge, face. Scope to: body. Scope by: bodies, location only, vertex, edge, face. Orientation coordinate system: any; defaults to Global Cartesian. Heat Reaction

Steady-state thermal, transient thermal

Heat: overall

Scope to: body. Scope by: boundary condition. Not available to the Samcef solver.

Radiation1 (p. 954)

Steady-state thermal, transient thermal

Net Radiation, Emit- Scope to: face. ted Radiation, Reflected Radiation, Incid- Scope by: boundary condient Radiation tion (Radiation loads with Surface-to-Surface correlation). Not available to the Samcef solver.

1 — For 2D plane stress models the Radiosity Solver method assumes an infinite third dimension so the Radiation Probe results will be proportional to the Workbench model thickness. See the Probes (p. 1001) section for further information.

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Magnetostatic Results

Magnetostatic Results A magnetostatic analysis offers several results items for viewing. Results may be scoped to bodies and, by default, all bodies will compute results for display. You can use the Details view to view vector results in several ways. Magnetic Flux Density, Magnetic Field Intensity, and Force represent the magnitude of the results vector and can be viewed as a contour or as a directional vector. Any directional solution represents direction vector components (X, Y, Z) of the vector. They may be displayed as a contour. The following electromagnetic result topics are addressed in this section: Electric Potential Total Magnetic Flux Density Directional Magnetic Flux Density Total Magnetic Field Intensity Directional Magnetic Field Intensity Total Force Directional Force Current Density Inductance Flux Linkage Error (Magnetic) Magnetostatic Probes Magnetostatic Probes (p. 958) can be used to determine the following results: • Flux Density • Field Intensity • Force Summation • Torque • Energy • Magnetic Flux

Electric Potential Electric potential represents contours of constant electric potential (voltage) in conductor bodies. This is a scalar quantity.

Total Magnetic Flux Density Magnetic Flux Density is computed throughout the simulation domain and is a vector quantity. Selecting this option allows you to view the magnitude of the vector as a contour or as a directional vector.

Directional Magnetic Flux Density Magnetic Flux Density vector components are computed throughout the simulation domain. Selecting this option allows you to view individual vector components (X, Y, Z) as a contour.

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Using Results

Total Magnetic Field Intensity Magnetic Field Intensity is computed throughout the simulation domain and is a vector quantity. Selecting this option allows you to view the magnitude of the vector as a contour or as a directional vector.

Directional Magnetic Field Intensity Magnetic Field Intensity vector components are computed throughout the simulation domain. Selecting this option allows you to view individual vector components (X, Y, Z) as a contour.

Total Force Total Force results represent electromagnetic forces on bodies. This is a vector quantity. Selecting this option allows you to view the magnitude of the vector as a contour or as a directional vector.

Directional Force Vector components of force and torque are computed throughout the simulation domain. They are meaningful only on non-air bodies. Selecting this option allows you to view individual vector force components (X, Y, Z) as a contour. The total summed forces and torque are available in the Details view. For example, requesting the z component of directional force/torque will report the net force acting in the z direction and the net torque acting about the z axis of the specified coordinate system.

Current Density Current density can be computed for any solid conductor body. It is displayed as a vector and is best viewed in wireframe mode. You can use the Vector toolbar to adjust the vector arrow viewing options. You can use the element-aligned option in the Vector toolbar for current density vectors, but not the grid-aligned option.

Inductance Inductance can be computed for conductor bodies. It is defined as a measure of the differential change in flux linkage to the differential change in current. This is represented by the equation below, where dψ is the differential change in flux linking conductor j produced by a differential change in current for conductor i. Note that this is valid for linear and nonlinear systems, the inductance will be a function of current. ψ = ij

ij

i

Inductance is often used as a parameter in electric machine design and in circuit simulators. A conductor body must have a current load to be considered in inductance calculations. Inductance results are presented in the Worksheet View. The results are presented in table form. The example below shows inductance results for a two-conductor system. The diagonal terms represent self-inductance, while the off-diagonal terms represent mutual inductance. In this case, L11 = 1e — 4, L22 = 8e — 4, L12 = L21 = 4e — 4 Henries. Cond1 (H) Cond1 1e-4 956

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Magnetostatic Results Cond2 4e-4

8e-4

The Details view for inductance allows you to define a Symmetry Multiplier. Use this if your simulation model represents only a fraction of the full geometry. The multiplier should be set to compensate for the symmetry model. For example, if you create a half-symmetry model of the geometry for simulation, set the Multiplier to ‘2.’ Changing the multiplier will update the Worksheet results.

Note • Computing inductance can be time-consuming and should only be used if needed. • Loads (Voltage, and Current) must be constant when Inductance is specified. Tabular and function loads are not supported. • Inductance can only be used with a single step, single substep solution. User settings to the contrary will be overridden. • Inductance requires the Direct solver setting (default) for the Solver Type property of Analysis Settings. User settings to the contrary will be overridden.

Flux Linkage Flux linkage can be computed for any system incorporating a conductor. Solving for flux linkage calculates the flux, ψ, linking a conductor. This is commonly referred to as the «flux linkage.» For nonlinear systems, the flux linkage will be a function of current. Flux linkage is also a function of stroke (e.g., displacement of an armature). Flux linkage is often used to compute the emf (electromotive force) in a conductor, defined using the equation below, where V is the electromotive force, typically expressed in volts. =−

ψ

Conductor bodies must have defined current loads to be considered in flux linkage calculations. Flux linkage results are presented in the Worksheet View. The results are presented in table form. The example below shows flux linkage results for a two-conductor system. Flux Linkages (Wb) Cond1 5e-4 Cond2 10e-4 The Details view for flux linkage allows you to define a Symmetry Multiplier. Use this if your simulation model represents only a fraction of the full geometry. The multiplier should be set to compensate for the symmetry model. For example, if you create a half-symmetry model of the geometry for simulation, set the Multiplier to ‘2.’ Changing the multiplier will update the Worksheet results.

Note • Computing flux linkage can be time-consuming and should only be used if needed.

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Using Results • Loads (Voltage, and Current) must be constant when flux linkage is specified. Tabular and function loads are not supported. • Flux linkage can only be used with a single step, single substep solution. User settings to the contrary will be overridden. • Flux linkage requires the Direct solver setting (default) for the Solver Type property of Analysis Settings. User settings to the contrary will be overridden.

Error (Magnetic) The description of this result is similar to Error (Structural) except that flux density is the basis for the errors instead of stresses. When all materials are linear, Workbench uses relative permeability (MURX, MURY, MURZ) values which are available in the material properties. When nonlinear materials are present, Workbench does not extract relative permeability from the material properties. Instead, for a given element, Workbench first sums the flux density vectors of the result nodes to form a vector called B. Workbench next sums the field intensity vectors of the result nodes to form a vector called H. MURX, MURY, and MURZ are all assigned the value ( |B|/|H| ) / MUZERO, where: • |B| is the length of the B vector, • |H| is the length of the H vector, • MUZERO is free space permeability. If the H vector has a zero length, the contribution of this element to the energy error will be set to 0.

Magnetostatic Probes The following magnetostatic probe types are available. Probe Type

Applicable Analysis Output Types

Characteristics

Flux Density

Magnetostatic

Scope to: body.

Flux Density: X axis, Y axis, Z axis

Scope by: bodies, location only, vertex, edge, face. Orientation coordinate system: any; defaults to Global Cartesian.

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Magnetostatic Results Probe Type

Applicable Analysis Output Types

Field Intensity

Magnetostatic

Characteristics

Flux Intensity: X axis, Scope to: Y axis, Z axis body. Scope by: bodies, location only, vertex, edge, face. Orientation coordinate system: any; defaults to Global Cartesian.

Force Summation

Magnetostatic

Force Sum: X axis, Y axis, or Z axis; Symmetry Multiplier

Scope to: body. Scope by: bodies. Orientation coordinate system: any; defaults to Global Cartesian.

Torque

Magnetostatic

Torque:1 (p. 960) X axis, Y axis, or Z axis; Symmetry Multiplier

Scope to: body. Scope by: bodies. Orientation coordinate system: any; defaults to Global Cartesian. Summation: Orientation coordinate system.

Energy

Magnetostatic

Magnetic Co-energy

Scope to: body. Scope by: System or per body.

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959

Using Results Probe Type

Applicable Analysis Output Types

Magnetic Flux

Magnetostatic

Magnetic Flux2 (p. 960)

Characteristics Scope to: body. Scope by: edge.

1 — Torque results represent the torque on a body due to electromagnetic forces. Torque is specified about the origin of a coordinate system. By default, the global coordinate system is used. To change the specification point, create a local coordinate system and specify the results about the new origin. The torque result is listed in the Details view. 2 — Magnetic Flux is computed along the edge scoping. The scoping should produce a single continuous path along a model edge. Flux is reported as magnitude only. See the Probes (p. 1001) section for further information.

Electric Results The following electric result types are available: Result Type

Description

Electric Voltage

Represents contours of constant electric potential (voltage) in conductor bodies. This is a scalar quantity.

Total Electric Field Intensity

Is computed throughout the simulation domain and is a vector sum quantity. Selecting this option allows you to view the total magnitude of the vectors as a contour.

Directional Electric Field Intensity

Its vector components are computed throughout the simulation domain. This option allows you to view individual vector components (X, Y, Z) as contours.

Total Current Density

Can be computed for any solid conductor body. It is displayed as a vector and is best viewed in wireframe mode. You can use the Vector toolbar to adjust the vector arrow viewing options. You can use the element-aligned option in the Vector toolbar for current density vectors, but not the grid-aligned option.

Directional Current Density

Its vector components are computed throughout the simulation domain. This option allows you to view individual current density vector components (X, Y, Z) as contours.

Joule Heat

Occurs in a conductor carrying an electric current. Joule heat is proportional to the square of the current, and is independent of the current direction.

Note This result when generated by non-zero contact resistance is not supported.

Electric Probes (p. 961) can be used to determine the following results: • Electric Voltage 960

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Fatigue Results • Field Intensity • Current Density • Reaction

Electric Probes The following electric probe types are available. Probe Type

Applicable Analysis Types

Output

Characteristics

Electric Voltage

Electric

Voltage

Scope to: body. Scope by: bodies, location only, vertex, edge, face.

Field Intensity

Electric

X axis, Y axis, Z axis, Total

Scope to: body. Scope by: bodies, location only, vertex, edge, face. Orientation coordinate system: any; defaults to Global Cartesian.

Current Density

Electric

X axis, Y axis, Z axis, Total

Scope to: body. Scope by: bodies, location only, vertex, edge, face. Orientation coordinate system: any; defaults to Global Cartesian.

Reaction

Electric

Current: overall

Scope to: body. Scope by: boundary condition.

See the Probes (p. 1001) section for further information.

Fatigue Results Fatigue provides life, damage, and factor of safety information and uses a stress-life or strain-life approach, with several options for handling mean stress and specifying loading conditions. Common uses for the strain-life approach are in notched areas where, although the nominal response is elastic, the local response may become plastic. The three components to a fatigue analysis are: Fatigue Material Properties (p. 962) Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Results Fatigue Analysis and Loading Options (p. 963) Reviewing Fatigue Results (p. 966)

Fatigue Material Properties Engineering Data contains example materials which may include fatigue curves populated with data from engineering handbooks. You can also add your own fatigue curves. The Fatigue Tool will use the information from these curves for each material in the model when calculating life, damage, safety factors, etc. If Young’s Modulus is temperature dependent, then the fatigue calculations are carried out using the Young’s Modulus computed at the reference temperature of the body. For the strain-life approach, the materials must have Strain-Life Parameters defined. For the Stress-Life approach, the materials must have Alternating Stress defined. To add this data to a material follow the Add Material Properties procedure (see Perform Material Tasks in Engineering Data). • Alternating Stress The alternating stress, or stress-life (SN), mean curve data can be defined for a mean stress or r-ratio. The Interpolation method (Log-Log, Semi-Log, or Linear) can be defined. The curve data must be defined to be greater than zero. – Mean Stress Use this definition if experimental SN data was collected at constant mean stress for individual SN curves. – R-Ratio Use this definition if multiple SN curves were collected at a constant r-ratio. The r-ratio is defined as the ratio of the second loading to the first: r = L2 / L1. Typical experimental r-ratios are -1 (fully reversed), 0 (zero-based), and .1 (to ensure that a tensile stress always exists in the part). It is possible to define multiple SN curves to account for different mean stress or r-ratio values. The values of mean stress/r-ratio are only important if multiple curves are defined and the SN-Mean Stress Curves correction using experimental data option is chosen in the Fatigue Tool • Strain-Life Parameters The following four strain-life parameter properties and the two cyclic stress-strain parameters must have data defined: – Strength Coefficient – Strength Exponent – Ductility Coefficient – Ductility Exponent – Cyclic Strength Coefficient – Cyclic Strain Hardening Exponent Note that in Engineering Data, in the Display Curve Type drop down menu, you can plot either a Strain-Life or Cyclic Stress-Strain curve.

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Fatigue Results

Fatigue Analysis and Loading Options After you have defined the stress-life or strain-life curves for all materials in your model, you can choose your fatigue options and run the fatigue analysis. To select the fatigue analysis and loading options, you must select the Fatigue Tool Solution object from the Solution Context Toolbar, or via a right-mouse click. In the Details View (p. 11) you may specify the following options: • Fatigue Strength Factor (Kf ) • Loading Type • Scale Factor • Analysis Type • Mean Stress Theory • Stress Component • Units Name • 1 “Unit” is Equal To • Bin Size • Use Quick Rainflow Counting • Infinite Life • Maximum Data Points To Plot The Worksheet includes theoretical graphic information that reflects settings in the Details view.

Fatigue Strength Factor (Kf ) This is the fatigue strength reduction factor. The stress-life or strain-life curve(s) are adjusted by this factor when the fatigue analysis is run. This setting is used to account for a «real world» environment that may be harsher than a rigidly-controlled laboratory environment in which the data was collected. Common fatigue strength reduction factors to account for such things as surface finish can be found in design handbooks.

Loading Type Choose from the following: • Zero-Based (r=0) • Fully Reversed (r=-1) • Ratio • History Data • Non-proportional Loading (available only for stress-life applications) Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Results The first three are all constant amplitude, proportional loading types and are illustrated with a graph in the Geometry window. The fourth type, history data, allows you to navigate to a file containing the data points. This option is a non-constant amplitude proportional loading type. This data is depicted in a graph on the Worksheet. You can specify the number of data points this graph will display in the Maximum Data Points To Plot field located in the Details view of the Fatigue Tool. The fifth option is a non-proportional constant amplitude loading type for models that alternate between two completely different stress states (for example, between bending and torsional loading). Problems such as an alternating stress imposed on a static stress can be modeled with this feature. Non-proportional loading is applicable on fatigue tools under Solution Combination where exactly two environments are selected.

Scale Factor This setting scales the load magnitude. For example, if you set this to 3, the amplitude (and mean) of a zero-based loading will be 1.5 times the stress in the body. The graph in the Worksheet window will update to reflect this setting. This option is useful to see the effects of different finite element loading magnitudes without having to run the complete structural analysis repeatedly. Note that this scale factor is applied after the stresses have been collapsed from a tensor into a scalar. Thus any multiaxial stress collapse methods that are sensitive to the sign (Von-Mises, Maximum Shear, Maximum Principal) may not give the same answer had the scale factor been applied to the environment load itself.

Analysis Type Choose either Stress Life or Strain Life.

Mean Stress Theory This setting specifies how the mean stress effects should be handled. • If Analysis Type is set to Stress Life, choose from None, Goodman, Soderberg, Gerber, and Mean Stress Curves. The Goodman, Soderberg, and Gerber options use static material properties along with S-N data to account for any mean stress while Mean Stress Curves use experimental fatigue data to account for mean stress. The default mean stress theory can be defined through the Mechanical application Fatigue settings in the Options dialog box. • If Analysis Type is set to Strain Life, choose from None, Morrow, and SWT (Smith-Watson-Topper).

Note A sample plot of each of these theories is shown at the bottom of the Worksheet view. This plot does not use live data, but is rather a generic representation of each theory. For more information on these theories, see «Metal Fatigue In Engineering» by Ralph I. Stephens, et. al.

Stress Component Because stresses are multiaxial but experimental fatigue data is usually uniaxial, the stress must be converted from a multiaxial stress state to a uniaxial one. A value of 2 times the maximum shear stress is used. You can choose from several types, including component stresses, von Mises, and a signed von

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Fatigue Results Mises, which takes the sign of the absolute maximum principal stress. The signed von Mises is useful for accounting for any compressive mean stresses.

Units Name This field allows you to specify the name for the Life Units. The unit options include: • cycles

• hours

• blocks

• days

• seconds

• months

• minutes

• User Defined

User Defined Selecting the User Defined option displays the Custom Units Name field. Enter the name for your customized unit name in this field. The specified unit is reflected in the Details view for all applicable fatigue settings.

1 “Unit” is Equal To Where «unit» is either cycle or block based on the Units Name selection. Modify the field’s value based on the desired number of cycles or blocks for the units.

Bin Size This option appears only if Type is set to History Data (non-constant amplitude loading). This setting defines how many divisions the cycle counting history should be organized into for the history data loading type. Strictly speaking, this is number specifies the dimensions of the rainflow matrix. A larger bin size has greater precision but will take longer to solve and use more memory.

Use Quick Rainflow Counting This option appears only if Type is set to History Data (non-constant amplitude loading). Since rainflow counting is used, using a “quick counting” technique substantially reduces runtime and memory, especially for long time histories. In quick counting, alternating and mean stresses are sorted into bins before partial damage is calculated. This means that with quick counting active, calculations will be performed for maximum of binsize. Thus the accuracy will be dictated by the number of bins. Without quick counting, the data is not sorted into bins until after partial damages are found and thus the number of bins will not affect the results. The accuracy of quick counting is usually very good if a proper number of bins are used when counting. To see the effects of using quick counting, compare the results of constant amplitude loading to simulated constant amplitude loading from a load history file. With quick counting off, the result should match exactly but with quick counting on, there will be some error depending on the bin size and alternating stress value in relation to the midpoint of the bin the count is sorted into.

Infinite Life Stress Life Analysis

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Using Results This option appears only if Type is set to History Data (non-constant amplitude loading) and defines what life will be used if the stress amplitude is lower than the lowest stress on the SN curve. It may be important in how damaging small stress amplitudes from the rainflow matrix are. Strain Life Analysis Since the strain-life method is equation based it has no built-in limit, unlike stress-life for which the Fatigue Tool uses a maximum life equal to the last point on the SN curve. Thus to avoid skewed contour plots showing very high lives, you can specify Infinite Life in a strain-life analysis. For example, if you set a value of 1e9 cycles as the Infinite Life, the maximum life reported is 1e9.

Maximum Data Points To Plot This option is only applicable for History Data loading and allows you to specify the number of data points to display in the corresponding graph that appears in the Worksheet. The default value is 5000 points. The graph displays the full range of points and all points are used in the analysis. However, depending on the value you set, every second or third point may not be displayed in the interest of avoiding clutter and making the graph more readable.

Reviewing Fatigue Results After you have included the Fatigue Tool in your analysis, you can then choose from among several results options. Any of these results can be scoped to individual parts or faces if desired. To select the fatigue solution items, you must be under a Solution object. Click Fatigue Tool either on the toolbar or via a right-mouse click and select any of the following options: • Life (p. 966) • Damage (p. 967) • Safety Factor (p. 967) • Biaxiality Indication (p. 967) • Equivalent Alternating Stress • Rainflow Matrix (history data only) (p. 967) • Damage Matrix (history data only) (p. 968) • Fatigue Sensitivity (p. 968) • Hysteresis (p. 969)

Life This result contour plot shows the available life for the given fatigue analysis. If loading is of constant amplitude, this represents the number of cycles until the part will fail due to fatigue. If loading is nonconstant, this represents the number of loading blocks until failure. Thus if the given load history represents one month of loading and the life was found to be 120, the expected model life would be 120 months. In a constant amplitude analysis, if the alternating stress is lower than the lowest alternating stress defined in the S-N curve, the life at that point will be used.

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Fatigue Results

Damage Fatigue damage is defined as the design life divided by the available life. The default design life may be set through the Options dialog box. A damage of greater than 1 indicates the part will fail from fatigue before the design life is reached.

Safety Factor This result is a contour plot of the factor of safety (FS) with respect to a fatigue failure at a given design life. The maximum FS reported is 15.

Biaxiality Indication This result is a stress biaxiality contour plot over the model that gives a qualitative measure of the stress state throughout the body. A biaxiality of 0 corresponds to uniaxial stress, a value of -1 corresponds to pure shear, and a value of 1 corresponds to a pure biaxial state. For Non-proportional loading, you can choose between average biaxiality and standard deviation of biaxiality in the Details view.

Equivalent Alternating Stress The Equivalent Alternating Stress contour is the stress used to query the S-N curve. This result is not valid if the loading has non-constant amplitude (Loading Type = history data). The result is useful for cases where the design criteria is based on an equivalent alternating stress as specified by the fatigue analyst.

Rainflow Matrix (history data only) This graph depicts how many cycle counts each bin contains. This is reported at the point in the specified scope with the greatest damage. The Navigational Control at the bottom right-hand corner of the graph can be used to zoom and pan the graph. You can use the double-sided arrow at any corner of the control to zoom in or out. When you place the mouse in the center of the Navigational Control, you can drag the four-sided arrow to move the chart points within the chart.

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Using Results

Damage Matrix (history data only) Similar to the rainflow matrix, this graph depicts how much relative damage each bin has caused. This result can give you information related to the accumulation of the total damage (such as if the damage occurred though many small stress reversals or several large ones). The Navigational Control at the bottom right hand corner of the graph can be used to zoom and pan the graph. You can use the double-sided arrow at any corner of the control to zoom in or out. When you place the mouse in the center of the Navigational Control, you can drag the four-sided arrow to move the chart points within the chart.

Fatigue Sensitivity This plot shows how the fatigue results change as a function of the loading at the critical location on the scoped region. Sensitivity may be found for life, damage, or factory of safety. For instance, if you set the lower and upper fatigue sensitivity limits to 50% and 150% respectively, and your scale factor to 3, this result will plot the data points along a scale ranging from a 1.5 to a 4.5 scale factor. You can specify the number of fill points in the curve, as well as choose from several chart viewing options (such as linear or log-log). The Navigational Control at the bottom right hand corner of the graph can be used to zoom and pan the graph. You can use the double-sided arrow at any corner of the control to zoom in or out. When you place the mouse in the center of the Navigational Control, you can drag the four-sided arrow to move the chart points within the chart. To specify a result item, you must be under a Solution object.

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Fatigue Results

Hysteresis In a strain-life fatigue analysis, although the finite element response may be linear, the local elastic/plastic response may not be linear. The Neuber correction is used to determine the local elastic/plastic response given a linear elastic input. Repeated loading will form close hysteresis loops as a result of this nonlinear local response. In a constant amplitude analysis a single hysteresis loop is created although numerous loops may be created via rainflow counting in a non-constant amplitude analysis. The Hysteresis result plots the local elastic-plastic response at the critical location of the scoped result (the Hysteresis result can be scoped, similar to all result items). Hysteresis is a good result to help you understand the true local response that may not be easy to infer. Notice in the example below, that although the loading/elastic result is tensile, the local response does venture into the compressive region. Loading/Elastic Response:

Corresponding Local Elastic Plastic Response at Critical Location:

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Using Results

User Defined Results This section examines the purpose, operation, and use of the User Defined Result feature of Mechanical. Overview Characteristics Application Node-Based Scoping User Defined Result Expressions User Defined Result Identifier Unit Description User Defined Results for the Mechanical APDL Solver User Defined Results for Explicit Dynamics Analyses

Overview The User Defined Result feature allows you to derive user defined result values by performing mathematical operations on results obtained following a solution. Mechanical can generate user defined results, based on the analysis type. The user defined results can be derived from any number of fundamental results stored on the result file. You display these results using the Solution Worksheet. Using this feature, most of the results stored in the result file display in the worksheet as illustrated in this example.

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User Defined Results Refer to the following sections for descriptions of user defined result entries in the worksheet: • User Defined Results for the Mechanical APDL Solver (p. 979) • User Defined Results for Explicit Dynamics Analyses (p. 983)

Characteristics General: • All analysis types and solver targets can produce User Defined Results. A User Defined Result may be unique to a particular solver and analysis. After clicking on the Solution object, you must click on the Worksheet to produce the complete listing of the results that are applicable to the analysis type and solver being used. • All result types can be combined except for results which have different dimensions. For example, displacement vectors, which contain 3 items, cannot be added to stress tensors, which contain 6 items. • User Defined Results which are elemental (such as stress or strain results) can be displayed as averaged or unaveraged results. It takes Mechanical longer to display a result which is not averaged. Like most result types that display using contours, user defined results: • Are scoped to a geometry (vertex, edge, face, body), named selection, path, or surface. However, you cannot scope user defined results based on Contacts to a path or surface. • Require a set, time, and frequency/phase, to be fully specified (depending on the analysis type). • Display minimum/maximum values and a Graph. • Display nodal averaged data. • Can be added to a Chart • Can be examined using probe annotations, slice planes, isosurface, etc. • Can be cleared. • Can be duplicated. Unlike other contour results, user defined results: • Can be duplicated or copy/pasted except for identifiers. • Can have a variable unit category assigned to its contour. • Become obsolete if a user defined result is dependent upon another user defined result that has been modified, cleared, or deleted. In this instance, the graphic of the geometry displays without results. • User defined results cannot employ Probes. • User defined results cannot link to multiple environments and cannot employ the Solution Combination feature.

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Using Results

Application Apply a User Defined Result using one of the following methods: • Select the User Defined Result toolbar button. • Right-click the Solution object and the select the User Defined Result option. • Display the Solution Worksheet following a Solve, right-click the mouse on the desired row of the table, and then select Create User Defined Result. Until you become familiar with this feature, it is recommended that you insert user defined results using the worksheet. This makes sure that results are valid and applicable for the particular analysis type and solver being used. As illustrated below, right-clicking the mouse on a row of the worksheet displays an option to create a user defined result.

Note NMISCxxx and SMISCxxx results are not displayed in the worksheet and can only be accessed by typing in the keyword directly. See User Defined Results for the Mechanical APDL Solver (p. 979) for details. Selecting this option places a User Defined Result object for the specified result in the tree as a child of the Solution object, as shown in the example below. Compared to the other two methods for inserting a User Defined Result, this technique automatically completes field data in the Details view. Note that the new result object’s name appears in the Expression field of the Details view. Except for an Identifier, all remaining details are also automatically generated based on the information provided by the result type, such as Input Unit System (U.S. Custom) and Output Unit (Displacement). If you create a user defined result and do not use the worksheet as the origin, you need to manually enter an Expression and also define the Output Unit. These fields display with a yellow highlight to indicate the required entries. See the User Defined Result Expressions and Unit Description sections for more information.

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User Defined Results

Once a user defined result is created, the advantage of the feature is your ability to further define expressions using mathematical operators. For example, you can enter the mathematical combination UX+UY in the Expression field and then retrieve a new result.

Node-Based Scoping In regard to usage, suppose two user defined results (with identifiers A and B, respectively) are scoped to ScopeA and ScopeB. The algorithm to draw the contours for C = A + B (scoped to ScopeC) proceeds as follows: • The results A and B are combined on all common bodies (determined from ScopeA and ScopeB and referred to as CommonBodies). Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Results • The scope (ScopeC) of the newly defined result C is then employed: the contours of C are drawn on the intersection of ScopeC and CommonBodies. Note, each of ScopeA, ScopeB, and ScopeC can be any set of geometric entities: vertices, edges, faces, bodies, or named selections (consisting of geometric entities or even nodes in the mesh). Example 5: Nodal Scoping Assumptions: A is scoped to bodies 1 and 2 and B is scoped to two faces , one in body 2 and one in body 3. The combination C = A+B is scoped to two vertices, one in body 2, and the other in body 3. Result: A+B will be computed on nodes common to the underlying bodies of A and B; these nodes will exist only in body 2. Then the combination C = A + B will be displayed only on the vertex belonging to body 2 (the one belonging to body 3 is not in the intersection of the two original scoping bodies).

User Defined Result Expressions The term “expression” has more than one use when defining user defined results. An expression is: • Primarily, the combination of mathematical values, based on syntax rules and the available math operations. • A column displayed on the Solution Worksheet that indicates the result type. • An entry field in the Details view of a user defined result where you enter mathematical values, such as UX+UY+UZ.

Note You can use user defined result expressions across multiple combinations of environments with limited functionality by using a Design Assessment system. However, you can not use it within standard Solution Combinations. The example of the Solution Worksheet shown below highlights the Expression column.

When a User Defined Result is applied, the content of the above column populates the Expression field of the user defined result’s Detail View. In this case, UX.

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User Defined Results

The content of the Expression field can be modified using mathematical operators to further define the expression. As shown below, you can combine the X, Y, and Z components and then retrieve a new customized result.

Expression Syntax Expressions support the following syntax: • Operands: ( ‘+’, ‘-‘,’*’, ‘/’, ‘^’) • Functions: (sqrt(), min()…) — always use lower case • Numbers: (scalar quantities such as 1.0, 25, -314.23, or 2.5e12)

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Using Results • Identifiers: unique user defined names

Supported Mathematical Operations The following is a list of the mathematical operations currently supported for user defined results. The shorthand notation «s» defines a single-valued quantity (constant values such as 1.34) and «a» defines an array. An array is distinguished by its dimension which includes the length, based on the number of rows (that is, number of nodes or elements), and the width, consisting of 1, 3, or 6 columns depending on the type of result stored. • Addition (+): s1+s2, a1+a2, a+s (s+a is not supported) • Subtraction (-): s1-s2, a1-a2, a-s (s-a is not supported) • Multiplication (*): s1*s2, a1*a2, a*s, s*a • Division (/): s1/s2, a1/a2, a/s (s/a is not supported) • Power (^): s1^s2, a^s, (undefined if s1 = 0 and s2 < 0) • Log base ten (log10): log10(s), log10(a), (s and a > 0.0) • Square root (sqrt): sqrt(s), sqrt(a), (s and a should be >= 0.0) • Dot product (dot): dot(a1,a2) (results in a single-column array consisting of the inner products, one for each row of a1 and a2; thus, a1, a2 should have the same dimensions) • Cross product (cross): cross(a1,a2) (a1, a2 must have 3 columns) • Add Comp (addcomp): addcomp(uvectors) = ux + uy + uz (If the argument uvectors has 3 columns, they are added to produce a single-column array. If the argument is a single-column array, the result will be a scalar summing all the array entries.) • Maximum (max): s = max(s1,s2), a = max(a1,a2) • Minimum (min): s = min(s1,s2), a = min(a1,a2) • Absolute Value (abs): s = abs(s1), a=abs(a1) • Trigonometric Functions (sin, cos, tan): sin(s), cos(s), tan(s), sin(a), cos(a), tan(a) (s and a are both in radians) • Inverse Trigonometric Functions (asin, acos, atan): asin(s), acos(s), atan(s), asin(a), acos(a), atan(a) (return values are in radians; where -1 <= s <= 1 and -1 <= a <=1 for asin and acos) • atan2: atan2(s1,s2), atan2(a1,a2) (return values are in radians; calculates the arctangent of s1/s2 or a1/a2 and uses the sign of the arguments to determine the quadrant of the returned angle)

Note • The current expression list does not allow input parameters from the Parameter Workspace. Only output parameters are allowed for Min and Max values of a user defined result. • All operations involving two vector arrays must have the same dimensionality.

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User Defined Results • Any result whose expression contains the addcomp function needs to be scoped to exactly one body. • You cannot perform mathematical operations directly within the Design Assessment system. However, the Design Assessment system provides the ability to use python scripts to combine results from various environment using highly complex, user defined mathematical functions.

User Defined Result Identifier Each user defined result you create can be assigned a unique name using the Identifier field in the Details view as illustrated below.

User defined identifiers: • Can begin with a letter or an underscore character. • Can contain any number of letters, digits, or underscores. • Are not case insensitive — however, functions should always use lowercase (sqrt, max, min, etc.). • Are not affected by the order in which they are entered. For example, for Identifiers A and B, the expression for: – User defined Result 1 can equal: B = 2*A, and: – User Defined Result 2 can equal: A = UX It is recommend that you use the proper order and try to define dependents first. For example, define A, B, C and then D = A^2+B^2+C^2 • Cyclic dependencies are blocked, such as the following: – User Defined Result 1: A = UX + C Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Results – User Defined Result 2: C = 2 * A — 1 • Correspond to an array over all nodes (or all elements): – Length = number of nodes (or elements) – Width = 1, 3, or 6 columns An Identifier, together with Expression content (UX, UY, etc.), can be used in combination with other user defined results. For example, using the Identifier MyResult, you could create the Expression: sqrt(MyResult+UX+UY). In addition, if an Identifier is used in an expression, it must be scoped to the same geometry. It is recommended that when you assign an identifier to the expression of a user defined result, that you rename the tree object with the same name/identifier.

Limitations of the User Defined Result Identifier There are several problematic scenarios that can arise when you use the Identifier of an existing user defined result to create a new user defined result. For each scenario, changing an item in the Details view of the new result causes the new result to be unreliable. For example, the Display Time of a User Defined Result is only relevant when the expression consists of built-in identifiers. Unlike user defined identifiers, built-in identifiers retain their time dependence through the evaluation of the expression. To reveal the built-in identifiers for a given solver, examine the Worksheet view on the Solution folder. Note that Mechanical may not necessarily issue a warning or error message for these situations. Suppose the Identifier of the original result is «Original». Further, suppose that the Expression of the new result is «2 * Original». Consider the following scenarios: • Different choices of By Time or By Result Set • Different choices of the value of Display Time or Set • Different choices of Coordinate System • Different choices of Yes/No for Calculate Time History • Different choices for Use Average

Unit Description The units of a user defined result are defined by the following Detail view settings: • Input Unit System: A read-only field that displays the active Mechanical application unit system. To evaluate an expression, a user defined result’s units must be converted to the Input Unit System. As a result, the expression is most easily verified when the intervening data is viewed in the Input Unit System. • Output Unit: The physical dimension assigned to a user defined result. It determines which factors are used to convert the result from its Input Unit System to the current unit system selection. Units are defined in a two step process.

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User Defined Results 1. Before you evaluate an expression, the units are converted to the Input Unit System. 2. Once evaluated, values are converted from the input system to the active Mechanical application unit system using the appropriate factor. For example, given the following user defined result expressions with MKS (m, kg, N, ºC, s, V, A) units: • FORCE_MKS=FSUM • STRESS_MKS=SEQV • DISP_MKS=USUM If you change the unit system to CGS (cm, g, dyne, ºC, s, V, A) and create a new user defined result with Expression =FSUM+SEQV+USUM and select Volume for the Output Unit property, you will produce the following user-defined results: Custom Identifier

Expression

Input Unit System

Output Units

FORCE_MKS

FSUM

Metric (m, kg, N, s, V, A)

Force

STRESS_MKS

SEQV

Metric (m, kg, N, s, V, A)

Stress

DISPL_MKS

USUM

Metric (m, kg, N, s, V, A)

Displacement

VOLUME_CGS

FSUM+SEQV+USUM

Metric (cm, g, dyne, s, V, A)

Volume

The expression VOLUME_CGS is easy to verify for its Input Unit System, CGS. If FSUM=3 dyne, SEQV=17 dyne/cm² and USUM=2 cm, (as seen in when CGS is selected in the Mechanical application), VOLUME_CGS produces the value 22 cm³. Any subsequent changes to the unit system in the Mechanical application cause each of the user defined results to convert based on their required factors. In this manner, VOLUME_CGS will use a factor of 1000 to convert from Metric CGS to Metric mm, because it represents a Volume. FORCE_MKS, STRESS_MKS and DISPL_MKS will convert differently, based on the selected Output Units.

User Defined Results for the Mechanical APDL Solver Refer to the PRNSOL and PRESOL command pages in the Mechanical APDL application Commands Reference for descriptions of most Component and Expression entries in the table. Some other entries are self-explanatory (SUM for example). VECTORS refer to vector plot results that include arrows in the display. The following tables include descriptions of other user defined result names not included in the PRESOL/PRNSOL listings. Nodal Results Nodal results are most often associated with degree of freedom solutions (like nodal reactions). Name

Description

R

Nodal rotations in a structural analysis (analogous to PRNS,ROT)

OMG

Nodal rotational velocities in a structural transient dynamic analysis (analogous to PRNS,OMG)

DOMG

Nodal rotational accelerations in a structural transient dynamic analysis (analogous to PRNS,DMG)

MVP_AZ

Nodal Z magnetic vector potential in an axisymmetric electromagnetic analysis (analogous to PRNS,A)

LOC

Nodal locations (x,y,z) Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Results Name

Description

LOC_DEF Deformed nodal locations (x+ux,y+uy,z+uz) F

Nodal structural forces (reaction)1

M

Nodal structural moments (reaction)1

CSG

Nodal magnetic current segments (reaction)

HEAT

Nodal thermal heat flow (reaction)

AMPS

Nodal electric current (reaction)

NDIR

Nodal THXY, THYZ, and THZX values. The NDIRVECTORS display consists of triads.

1 — When user defined results FX, FY, FZ, FSUM, and FVECTORS (and MX, MY, MZ, MSUM, and MVECTORS) are scoped to a path, then it is possible that no contours will be displayed. The reason is that these types of forces/moments are solved only at constrained nodes. The result value at a path point is interpolated from the nodal values of the elements that contain the path point. If a path point touches an element in which some nodes have undefined reactions, then Mechanical cannot properly interpolate the nodal values for the path point. No contour color is displayed at such a path point. Elemental Results Elemental results can exist at the nodes (like stress and strain) or can exist at the centroid (like volume). Name

Description

SPSD

Element nodal equivalent stress as calculated by the solver.

EPELEQV_RST

Element nodal equivalent elastic strain as calculated by the solver.

EPPLEQV_RST

Element nodal equivalent plastic strain as calculated by the solver.

EPCREQV_RST

Element nodal equivalent creep strain as calculated by the solver.

EPTOEQV_RST

Element nodal equivalent total strain as calculated by the solver, that is, EPTOEQV_RST is total mechanical strain: EPTOEQV_RST = EPELEQV_RST + EPPLEQV_RST + EPCREQV_RST.

EPTTEQV_RST Element nodal equivalent total strain (plus thermal strain) as calculated by the solver, that is, EPTTEQV_RST is total mechanical and thermal strain: EPTTEQV_RST = EPELEQV_RST + EPPLEQV_RST + EPCREQV_RST + EPTHEQV_RST. ETOP

Element nodal densities used for topological optimization (same as TOPO).

BEAM

Element nodal beam stresses: direct, minimum bending, maximum bending, minimum combined, maximum combined.

SVAR

Element nodal state variable data.

CONTJHEA

Element nodal Joule heat for CONTA174.

CONTFORC

Element nodal contact normal forces for CONTA175.

BEAM_AXIAL_F

Element nodal axial force vectors for BEAM188/189.

BEAM_BEND- Element nodal bending moment vectors for BEAM188/189. ING_M BEAM_TORSION_M

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Element nodal torsion moment vectors for BEAM188/189.

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User Defined Results Name

Description

BEAM_SHEAR_F Element nodal shear force vectors for BEAM188/189. ENFO

Element nodal reaction forces for structural analyses.

EHEAT

Element nodal heat values for thermal analyses.

CURRENTSEG

Element nodal magnetic current segments.

VOLUME

Element volumes.

ENERGY

Element potential and kinetic energies.

RIGID_ANG

Element Euler angles for MASS21 elements (rotation about x-axis, rotation about y-axis, rotation about z-axis).

CONTSMISC

Element summable miscellaneous data for contact elements. CONTSMISC is completely analogous in implementation to SMISC (see “User Defined Results Not Displayed in Worksheet” below), except that CONTSMISC, for display purposes, extrapolates the single elemental value to the corner nodes.

CONTNMISC

Element non-summable miscellaneous data for contact elements. CONTNMISC is completely analogous in implementation to NMISC (see “User Defined Results Not Displayed in Worksheet” below), except that CONTSMISC, for display purposes, extrapolates the single elemental value to the corner nodes.

EDIR

Elemental THXY, THYZ, and THZX values: (1) currently only angles of first node in solution record are employed; (2) the EDIRVECTORS display consists of triads.

PNUMTYPE

Element type reference numbers.

PNUMREAL

Real constant set numbers.

PNUMMAT

Material set numbers.

PNUMSEC

Section numbers.

PNUMESYS

Element coordinate system numbers (note: a 0 value corresponds to the global Cartesian system).

PNUMELEM

MAPDL element ID.

SMISC

Element summable miscellaneous data.

NMISC

Element non-summable miscellaneous data.

EFFNU_ZERO_EPElement nodal equivalent total strain (EPEL + EPPL + EPCR) as calculated by the postTOEQV processor. For average results, the solver averages the element nodal component strains at common nodes and performs a Von Mises calculation with effective Poisson’s Ratio set to ZERO. EFFNU_ZERO_EPTTEQV Element nodal equivalent total strain plus thermal strain (EPEL + EPPL + EPCR + EPTH) as calculated by the post-processor. For average results, the solver averages the element nodal component strains at common nodes and performs a Von Mises calculation with effective Poisson’s Ratio set to ZERO. Using this data, you can explicitly define your user defined result, such as total deformation by using the component deformations across all of the nodes in the model, identified by UX, UY, and UZ. You can use these component values to mathematically produce a user defined result for total deformation: SQRT(UX^2+UY^2+UZ^2). Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Results Notes If the Display Option is set to Averaged, then for the results ENFO, EHEAT, and CURRENTSEG, the result at each node represents the sum (or contributions) of all the elements that contain the node. If the Display Option is set to Unveraged, the ENFO result is analogous to PLES,FORCE. SPSD is a User Defined Result that is unique to the Mechanical APDL result file. For any element that supports stresses, the SPSD result represents the equivalent stress, for each corner node in the element, as stored on the result file. Hence, SPSD is the equivalent stress as calculated by the Mechanical APDL solver for the corner nodes. For this result, SPSD is the expression displayed in the Type column and Stress is displayed in the Output Unit column. Prior to release 13.0, SPSD represented the equivalent stress as calculated from component stresses during postprocessing, that is, it was not calculated by the Mechanical APDL solver. By default, Contact Results (accessible through User Defined Results via CONTSTAT or CONTFLUX – see the User Defined Results for the Mechanical APDL Solver section.) are not written to the result file in a thermal analysis. To write them, issue the RSTSUPPRESS,NONE command via a Command object at the /SOLU level. Displays of PNUM results are analogous to EPLOTs with the following commands in MAPDL: • /PNUM,TYPE,1 • /PNUM,REAL,1 • /PNUM,MAT,1 • /PNUM,SEC,1 • /PNUM,ESYS,1 • /PNUM,ELEM,1 For example, the range of the values of the PNUMTYPE result vary from the smallest element type to the largest element type, as created by ANSYS ET commands.

Note PNUM results are available for all analyses supported by MAPDL. For non-linear analyses, user defined results corresponding to MAPDL PLES commands with NL as an Item are available with the following components: SEPL, SRAT, HPRE, EPEQ, PSV, PLWK, CRWK, ELWK, SGYT, and PEQT Although there are no user defined results with SEND in Mechanical, you can use the following: Use This

For This

NLPLWK

PLES,SEND,PLASTIC

NLCRWK

PLES,SEND,CREEP

NLELWK

PLES,SEND,ELASTIC

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User Defined Results

User Defined Results Not Displayed in Worksheet For the Mechanical APDL solver, there are User Defined Results associated with summable miscellaneous data (SMISC) and non-summable miscellaneous data (NMISC) on the result file. These results are not listed in the Solution Worksheet. Because this data can be voluminous, by default, Mechanical does not write it to the result file for all element types in the model (examples of MISC records always written to the result file include beam, joint, and spring element types). You activate miscellaneous output for all elements or just contact elements using the Output Controls available in the Details of the Analysis Settings object. Mechanical has adopted a convention that miscellaneous data for contact elements be called CONTSMISC and CONTNMISC. This means that SMISC and NMISC data will only display on noncontact elements and that CONTSMISC and CONTNMISC data will only display on contact elements. You can also request and store state variables such as USERMAT or USERCREEP if you wish to utilize user-defined materials. Like miscellaneous data, SMISC and NMISC, the state variables do not display in the Solution Worksheet. You access state variables using the expression field entry SVAR followed by the state variable number. To display these results: 1. Click on the User Defined Result toolbar button. 2. In the Details view Expression field, type the string SMISC or NMISC followed by the sequence number which indicates the desired datum. For example, to display the 2nd sequence number for SMISC, enter SMISC2 for the Expression. The graphics contour display will be similar to the Mechanical APDL display for the command PLESOL,SMISC,2. When you evaluate this result, the Details view will show no units and no coordinate system for this data. That is, no unit conversions and no coordinate transformations are performed. If you enter a data expression that does not exist on the result file, the result will not be evaluated. To display the 2nd sequence number for summable miscellaneous data on scoped contact elements, enter CONTSMISC2 for the Expression.

User Defined Results for Explicit Dynamics Analyses Presented below are the user defined results that are specific to an explicit dynamics analysis using the AUTODYN solver. Variable

Description

Type

BEAM_LEN

Beam length

BOND_STATUS

The number of nodes bonded to the faces on an element during Elemental the analysis. A value of -1 is shown where all the bonds for the face have broken.

C_S_AREA

Beam cross section area

Element Nodal

COMPRESS

Material compression

Element Nodal

Compression, µ = ρ/ρ0

Element Nodal

CROSS_SECTION

Beam cross section number

Elemental

DAMAGE

Material Damage

Element Nodal

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Using Results Variable

Description

Type

1- fully fractured DENSITY

Material Density

Element Nodal

EFF_STN

Effective Geometric Strain of a cell

Element Nodal

EFF_PL_STN

Effective Plastic Strain. Note: This is calculated incrementally, Element unlike the equivalent plastic strain (EPPLEQV), which is calculated Nodal as an instantaneous value.

ENERGY_DAM

Energy resulting from fracture for the Johnson-Holmquist brittle Element strength model Nodal

EROSION

Erosion Status

Elemental

0 — no erosion >0 — eroded. (will not be displayed) EPS_RATE

Effective Plastic Strain Rate

Element Nodal

F_AXIAL

Beam axial force

Element Nodal

INT_ENERGY

Internal energy of the material

Element Nodal

MASS

Mass of material in an element

Element Nodal

MATERIAL

Material index. The material index as defined in the Explicit solver. There is not always a direct one-to-one correlation with materials defined in Engineering Data and the those used in the Explicit solver.

Elemental

For layered section shells, the MATERIAL for individual layers can be shown by using the Layer property in the results details view. MOM_TOR

Beam rotation inertia

Element Nodal

POROSITY

Material porosity

Elemental

Porosity, α = ρSolid/ρ PRESSURE

Pressure

Element Nodal

PRES_BULK

Dilation pressure for the Johnson-Holmquist brittle strength model

Elemental

SOUNDSPEED

Material soundspeed

Element Nodal

STATUS

Material Status

Elemental

1 – elastic

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User Defined Results Variable

Description

Type

2 – undergoing plastic flow 3 – failed due to effective criteria (with healing) 4 – failed due to effective criteria 5 – failed due to stress/strain in principal direction 1 6 – failed due to stress/strain in principal direction 2 7 – failed due to stress/strain in principal direction 3 8 – failed due to shear stress/strain in principal direction 12 9 – failed due to shear stress/strain in principal direction 23 10 – failed due to shear stress/strain in principal direction 31 For layered section shells, the STATUS for individual layers can be shown by selecting the Layer number in the results details view. STOCH_FACT

Stochastic factor applied when the stochastic property as definedElemental in the material failure model

STRAIN_XX

Total strain XX

Element Nodal

STRAIN_YY

Total strain YY

Element Nodal

STRAIN_ZZ

Total strain ZZ

Element Nodal

STRAIN_XY

Total strain XY. These are tensor shear strains, and not engineer- Element ing shear strains. Nodal

STRAIN_YZ

Total strain YZ. These are tensor shear strains, and not engineer- Element ing shear strains. Nodal

STRAIN_ZX

Total strain ZX. These are tensor shear strains, and not engineer- Element ing shear strains. Nodal

SUB_STN_X_SHELL_LAY- Shell total strain XX, sub-layer #. These are tensor shear strains, ER__# and not engineering shear strains.

Element Nodal

SUB_STN_Y_SHELL_LAY- Shell total strain YY, sub-layer #. These are tensor shear strains, ER__# and not engineering shear strains.

Element Nodal

SUB_STN_Z_SHELL_LAY- Shell total strain ZZ, sub-layer #. These are tensor shear strains, ER__# and not engineering shear strains.

Element Nodal

SUB_STN_XY_SHELL_LAY- Shell total strain XY, sub-layer #. These are tensor shear strains, ER__# and not engineering shear strains.

Element Nodal

SUB_STN_YZ_SHELL_LAY- Shell total strain YZ, sub-layer #. These are tensor shear strains, ER__# and not engineering shear strains.

Element Nodal

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Using Results Variable

Description

Type

SUB_STN_ZX_SHELL_LAY- Shell total strain ZX, sub-layer #. These are tensor shear strains, ER__# and not engineering shear strains.

Element Nodal

SUBL_EPS_SHELL_LAYER_#

Effective plastic strain, sub-layer #

Element Nodal

TEMPERATURE

Material Temperature

Element Nodal

THICKNESS

Shell Thickness

Element Nodal

TYPE

Element category (element number returned)

Elemental

HEX: 100-101 PENTA: 102 TET: 103-104,106 PYRAMID: 105 QUAD: 107 TRI: 108 SHL: 200-202, 204 BEAM: 203 VISC_PRES

Viscous pressure due to artificial viscosity

Element Nodal

VTXX

Viscoelastic stress XX

Element Nodal

VTYY

Viscoelastic stress YY

Element Nodal

VTZZ

Viscoelastic stress ZZ

Element Nodal

VTXY

Viscoelastic stress XY

Element Nodal

VTYZ

Viscoelastic stress YZ

Element Nodal

VTZX

Viscoelastic stress ZX

Element Nodal

For Euler (Virtual) Analyses The following results are multi-material variables in the AUTODYN solver. • EFF_PL_STN • INT_ENERGY • MASS

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User Defined Results • COMPRESS • DET_INIT_TIME • ALPHA • DAMAGE • TEMPERATURE For each Eulerian (Virtual) body in the analysis, a separate component will be available, which will allow the user to plot the result for the particular material associated with that body. The component name will be derived from the body name. There will also be an “ALL” component, which will displays results for all materials. Results for Lagrangian bodies can be viewed by selecting this “ALL” component. For a purely Lagrangian analysis, only the “ALL” component will be available to the user. For example, an analysis has two Eulerian (Virtual) bodies (Solid, Solid) and a Lagrangian Body (Surface Body), as shown in the image of the Outline View below.

In the User Defined Result Expression Worksheet, there are three components available for the multimaterial results, named SOLID, SOLID_2, and ALL.

Note It may be necessary to delete and reinsert multi-material results in order to view result for databases created prior to Release 13.0

For NBS Tetrahedral Elements The element variables listed below can be used to visualize the variable values at the nodes. The variable values presented in the element are a volume weighted average of those at the nodes. • TEMPERATURE Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Results • SOUNDSPEED • DENSITY • COMPRESS • STRAINS (NORMAL AND SHEAR) • EFF_PL_STN • TIMESTEP • INT_ENERGY The following variables are available as calculated directly from the solver in the element: • EFF_STN

Result Outputs The following topics related to result outputs are covered in this section. Chart and Table Contour Results Coordinate Systems Results Eroded Nodes in Explicit Dynamics Analyses Euler Domain in Explicit Dynamics Analyses Path Results Probes Surface Results Vector Plots Result Summary Worksheet

Chart and Table Selecting the Chart and Table icon button allows you to create charts of loads and/or results against time. In addition you can also chart result quantities against a load or another results quantity. You can also chart loads or results from across different analyses; for example, to compare the displacement response from two different transient runs with different damping characteristics. Use the Chart and Table feature to: • Chart load(s) and result(s) vs time. • Chart multiple harmonic response plots vs. frequency. • Change x-axis to plot a result against a load or another result. • Compare results across analyses. • Visualize and compress data into an easy-to-understand report.

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Result Outputs

Select Loads and Results from Tree Press the Ctrl or Shift key to select multiple objects of interest. In doing so, note that: • You can choose objects in the tree that belong to different analyses of a model. However all objects must belong to the same Model. • Only loads, probes and results that can be contoured are added to the chart. • For result items the variation of minimum and maximum values is plotted as a function of time

Select Chart icon from Standard Toolbar This adds a new chart object to the tree structure. You can add as many charts as needed.

Determining Data Points You can choose a mixture of loads and results that may even span different analyses. In these cases there can be a mismatch between the time points at which the loads are defined and the time points at which results are available. For example in case of a nonlinear transient stress analysis under constant load, the load has a single value but there can be many time points where results are available. The below interpolation scheme is used to create charts when such mismatch occurs. • Loads are interpolated or extrapolated to the time points at which result values or other load values. • Results are not interpolated or extrapolated

Details View Content The main categories are: • Definition: – Outline Selection: Lists how many objects are used in the chart. Clicking on the number of objects highlights the objects in the tree allowing you to modify the selection if needed. • Chart Controls: – X-Axis: By default the data of the selected objects are plotted against time. You may choose a different load or result quantity for the x-axis. For example you can plot a Force – Deflection curve by choosing the deflection to be the X-axis. – Plot Style: display as Lines, Points, or Both (default). – Scale: → Linear (default) — plot as linear graph. → Semi-Log (X) — X-Axis is plotted logarithmically. If negative axis values exist, this option has no effect. → Semi-Log (Y) — Y-Axis is plotted logarithmically. If negative axis values exist, this option has no effect.

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Using Results → Log-Log — X-Axis and Y-Axis are plotted logarithmically. If negative axis values exist, this option has no effect. – Gridlines: Show gridlines for plotting 2D X-Y curves. → Both — The gridlines for both the X-axis and Y-axis are shown. → X Axis — The gridline for the X-axis is shown. → Y Axis — The gridline for the Y-axis is shown. → None — No gridlines are shown. • Axis Labels: – X-Axis and Y-Axis: You can enter appropriate labels for the X and Y axes. In doing so, note that: → The X and Y axes always show the units of the item(s) being charted. These units are appended to any label that you enter. → When multiple items are plotted on the Y-axis the units are determined as follows: If all the items plotted on the Y-axis have the same units then the unit is displayed. For example, if all items are of type deformation and the active unit system is British Inch unit system then the unit is displayed as Inch. If the items plotted on the Y-axis are of different types for example, stress and strain then Normalized is displayed for unit. → When determining pairs of points to plot on the chart when X-axis is not time be aware that time is still used to determine the pairs of points to plot when an item other than time is used for the x-axis. Both the X-axis quantity and the Y-axis quantity must share a common time point to be considered a valid pair. • Report: – Content: By default both the chart as well as the data listing of the objects gets added to reports. Instead you may choose to only add the chart or only add the data listing or exclude the chart from report. Note that only tabular data or chart data with two or more points is displayed in the report. – Caption: You may enter a caption for the chart. The caption will be included in the report. • Input Quantities: – Input Quantities: Any valid load object added to the chart gets displayed under Input Quantities. If a load has multiple components then each component will get a line in this details group. – Output Quantities: Any valid result object added to the chart gets displayed under Output Quantities. If a result has multiple components then each component will get a line in this details group. In using Input and Output Quantities, note that: – Naming and legend: Each object added to a chart is assigned a name and a legend label. The name is simply the object name in the tree if there are no components associated with the object. An example would be a Y displacement probe. For objects that have multiple components the component direction or name will get added to the object name. For example adding ‘Equivalent

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Result Outputs Stress’ result item to a chart will result in two items getting added – ‘Equivalent Stress (min)’ and ‘Equivalent Stress (max)’. – Each name is preceded by a one letter label such as [A] or [B]. This label is also displayed on the corresponding curve in the chart and is used to associate the object name with the curve. – The default setting is to display the item in the chart and data grid. You can exclude an item by setting this field to Omit. Omitting an item removes the corresponding data from both data grid and chart. Be aware that an item chosen for X-axis cannot be omitted and this field will be reset to Display for that item.

Chart Display • Legend: You can use Show Legend /Hide Legend option via the right mouse button context menu to display or hide legends in the charts, the following limitations withstanding. – A maximum of 10 items will get displayed due to space limitations. – If more than 10 items are displayed in a chart then the curves will show all the prefixes even though the legend is limited to 10 items. You can refer to the details of the chart for the description of the items that corresponds to a prefix. • Normalization: Scaling of Y-axis is determined as follows. – Single item on Y-axis : Scaling is based on the minimum and maximum values of the item plotted – Multiple items on Y-axis that have same unit type: Scaling is based on the minimum and maximum values of the items plotted. For example, plot applied pressure load and a stress result against time. – Multiple items on Y-axis that have different unit types: In this case each curve is normalized to lie between 0 and 1, that is the minimum value is treated as zero and the maximum value as one. The label of the Y-axis reflects this by appending Normalized to any user specified label. Note that the data grid displays the actual values always.

Datagrid Display It is read-only.

Contour Results Most result types can be displayed using contours or vectors. The Result context toolbar applies to Solution level objects that display contour or vector results.

Coordinate Systems Results The following topics are addressed in this section: Nodal Coordinate Systems Results Elemental Coordinate Systems Results Rotational Order of Coordinate System Results

Nodal Coordinate Systems Results Every node in a model is associated with a coordinate system that, by default, is aligned with the global Cartesian coordinate system. If any of the X, Y, or Z axes of an individual node is rotated, the Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Results resulting coordinate system will typically not be aligned with the global Cartesian coordinate system. Using this feature, you can display nodal result rotations either as Euler rotated triads at each node location, or as contours that represent an Euler rotation angle about an individual nodal axis. Boundary conditions are highly dependent upon Euler angles. To display nodal coordinate systems results: Highlight the Solution object, and choose one of the following options from the Coordinate Systems drop down menu in the toolbar. A corresponding object will be inserted in the tree. • Nodal Triads: Displays an XYZ triad at each node representing the resulting rotation of the node’s coordinate system compared to the global Cartesian coordinate system. See Rotational Order of Coordinate System Results (p. 993) for details. • Nodal Euler XY Angle: Displays a contour plot representing the magnitude of the resulting Euler angle rotation at each node about the Z axis. • Nodal Euler YZ Angle: Displays a contour plot representing the magnitude of the resulting Euler angle rotation at each node about the X axis. • Nodal Euler XZ Angle: Displays a contour plot representing the magnitude of the resulting Euler angle rotation at each node about the Y axis.

Note For the ANSYS solver, nodal coordinate systems will not vary from time step to time step.

Elemental Coordinate Systems Results Every element in a model is associated with a coordinate system that, by default, is aligned with the global Cartesian coordinate system. If any of the X, Y, or Z axes of an individual element is rotated, the resulting coordinate system will typically not be aligned with the global Cartesian coordinate system. Using this feature, you can display elemental result rotations either as Euler rotated triads at each element’s centroid, or as contours that represent an Euler rotation angle about an individual elemental axis. Shell stresses are highly dependent upon Euler angles. To display elemental coordinate systems results: Highlight the Solution object, and choose one of the following options from the Coordinate Systems drop down menu in the toolbar. A corresponding object will be inserted in the tree. • Elemental Triads: Displays an XYZ triad at each element centroid representing the resulting rotation of the element’s coordinate system compared to the global Cartesian coordinate system. See Rotational Order of Coordinate System Results (p. 993) for details.

Note You may need to use the Wireframe viewing mode to see a particular triad in an element.

• Elemental Euler XY Angle: Displays a contour plot representing the magnitude of the resulting Euler angle rotation at each element centroid about the Z axis.

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Result Outputs • Elemental Euler YZ Angle: Displays a contour plot representing the magnitude of the resulting Euler angle rotation at each element centroid about the X axis. • Elemental Euler XZ Angle: Displays a contour plot representing the magnitude of the resulting Euler angle rotation at each element centroid about the Y axis.

Note For the ANSYS solver, it is possible for elemental coordinate systems to vary from time step to time step.

Rotational Order of Coordinate System Results The following rotational convention is used for both Nodal Coordinate Systems Results (p. 991) and Elemental Coordinate Systems Results (p. 992): 1. The first rotation is called … Euler XY and is in the X-Y plane (X towards Y, about Z). 2. The second rotation is called … Euler YZ and is in Y1-Z1 plane (Y1 towards Z1, about X1). 3. The third rotation is called … Euler XZ and is in X2-Z2 plane (Z2 towards X2, about Y2). X1, Y1, and Z1 refer to the coordinate system axes after the initial rotation about the global Z axis. X2, Y2, and Z2 refer to the coordinate system axes after the initial rotation about the global Z axis and subsequent rotation about X1. See Figure 3.2: Euler Rotation Angles from the Modeling and Meshing Guide for a pictorial representation of this convention.

Eroded Nodes in Explicit Dynamics Analyses During explicit dynamics analyses, highly distorted elements may be automatically removed (eroded) from the model. As elements erode, nodes may become free (not connected to any element). These nodes have mass and inertia and can impact other structures. By default, eroded nodes are plotted as red dots (see below).

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Using Results

The View> Eroded Nodes toggle from the Main Menu allows you to remove the eroded nodes from the display, as shown below.

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Result Outputs

Euler Domain in Explicit Dynamics Analyses In an Explicit Dynamics Analysis, if any bodies have a reference frame set to Eulerian (Virtual), an Euler domain is created that encloses all bodies in the model. The Euler domain is a structured hexahedral mesh. The exact size and resolution of the Eulerian domain can be controlled in the Euler Domain Controls section of the Analysis Settings Details view. Bodies with a reference frame set to Eulerian (Virtual) are used to initialize material into the Euler domain. The surfaces of the Eulerian bodies are not tracked exactly; the original mesh created by the mesher is discarded and the location of materials in the Euler domain is stored as a material (volume) fraction for each of the Euler cells. A representation of the material surface can be displayed as an isosurface for a material fraction value of 50%. A comparison of Lagrangian (left) and Eulerian (right) representations of the same body is shown below.

When plotting results on Eulerian bodies, the results calculated in the Eulerian domain are then interpolated onto this isosurface. If the Euler Tracking By Body option is selected in the Analysis Settings Details view, results may be scoped to Eulerian bodies in the same way as for Lagrangian bodies, and body trackers are available for Eulerian parts. Additional considerations: • Displacement, strain, and BOND_STATUS results are not available for scoped results. • Probes and path plots are not supported for Eulerian bodies. • External Force and Contact Force trackers will return zero for Eulerian bodies. • Point trackers for Strain are not supported. • Deformation scaling (i.e. Undeformed, .5 Auto, AutoScaling, 2x Auto, 5x Auto ) is not available for Eulerian bodies.

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Using Results • Show undeformed wireframe is not available for Eulerian bodies. • Show undeformed model is not available for Eulerian bodies. • Although it is not possible to view the Eulerian domain directly within the Mechanical application, the size and resolution of the domain are indicated in the graphics window when Analysis Settings are selected in the outline view; if required, the model may be transferred to an AUTODYN component system where the Euler mesh can be displayed. • There may be issues with solver efficiency for analyses containing more than ten Eulerian bodies. Further discussion of the Eulerian solver used by Explicit Dynamics Analyses, including a description of the theory, can be found in Key Concepts of Euler (Virtual) Solutions in the ANSYS Mechanical User’s Guide.

Path Results If you have already defined a path, you can view the path results by highlighting the result object, and in the Details view, setting Scoping Method to Path, then choosing the name of the particular path that you defined.

Note Path results are not supported for models using periodic or cyclic symmetry. An example path result plot is shown below.

In this example, the Number of Sampling Points for the Path object was set to 47. Results were calculated for each of these 47 points as shown in the Graph below.

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Result Outputs

For each point in a path or in a surface, Mechanical chooses precisely one body from which to calculate the results. If multiple bodies are scoped, Mechanical calculates the results from the body with the highest identifier (typically the latest one in the geometry tree). No averaging is done of a path result across bodies. If a path or a surface traverses multiple shell or solid bodies and if a path (or surface) point lies on the interface between distinct bodies, it may not be clear which body was employed in the creation of contour colors for the point. To avoid this situation, select the bodies from which to obtain the results. For example, a path can be defined by the edge between two shell bodies. If both bodies are scoped, the result contours on the path can be based on either body. In the following three figures, a path lies along the interface of two shell bodies. In the first two figures, a body is selected on one side of the path.

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Using Results

However, the stresses in the first figure differ from the stresses in the second figure.

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Result Outputs

In the third figure, the result is scoped to both bodies which touch the path.

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Using Results

Note that the stresses displayed in the third figure match those of the second image.

Interpolation and Paths For a given path, Mechanical examines each element in the set of scoped bodies to determine the set of elements which contain a point on the path. A path point may reside on a face of an element, in the interior of an element, or in no element. The set of path points is, in essence, a set of interpolation points. Assume, for example, that you request a normal x-axis stress result on the path (that is, SX). For a given interpolation point (x,y,z) lying on the face or residing in the interior of an element, Mechanical finds the natural (or normalized) coordinates of the point within the element. Mechanical then interpolates the corner values of SX, using the natural coordinates and shape functions, to find a value for SX at (x,y,z).

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Result Outputs

Probes Probes allow you to find results at a point on the model, or minimum or maximum results on a body, face, edge, or vertex; to find results on objects in the tree, such as elastic support or weak springs; or to obtain reaction forces and moments at supports. This section examines the general function of the probe tool in Mechanical as well as the specific probe types that are available in the Mechanical application. It also describes the Details view options associated with the Probe object. Overview and Probe Types Probe Details View

Overview and Probe Types The following probe types are available: • Structural Probes (p. 926) • Thermal Probes (p. 953) • Magnetostatic Probes (p. 958) • Electric Probes (p. 961) You insert a Probe object under Solution in the tree, from the toolbar or from a right mouse button click. You can adjust options in the Details view or add results for specific points/geometry. When you solve the probe, the display of the result probe reveals the displaced mesh for the specified time. The probe shows values over time and for a specified time. The Details view shows either the maximum or minimum value over time.

Note You cannot turn off the time history for result probe. Scoping Since probes are customized for the particular result type, different probes allow different scoping mechanisms. For example a reaction probe allows scoping to a boundary condition while a stress probe will allow scoping to an x, y, z location on the geometry. Refer to the “Characteristics” column of the tables in the linked sections above for scoping. Use Location Method in the Details view of the probe to scope to the desired entity. When you create a probe by clicking on a location or by assigning a coordinate system, Mechanical associates a small subset of nodes which reside near the probe. The value of this probe is interpolated from the values at these neighboring (undeformed) nodes. The interpolation is based on the original node locations and not a function of the displaced position of the probe or of the nodes. When picking a specific x, y, z location, you can obtain the probe result directly at the closest corner node, without extra interpolation, by right-clicking on the probe object in the tree and choosing Snap to mesh nodes

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1001

Using Results from the context menu. The identification number of the closest corner node is displayed as the Node ID in the Details view of the probe in the Results category.

Note If you attempt to intersect such probes with a line body, Mechanical issues a warning message. No results (such as stresses or displacements) will appear in the details view of the probe.

Note For surface bodies with expanded thickness, because the snapping location is located on the expanded mesh, while other items such as the original x, y, z location and the node ID are on the non-expanded mesh, you are advised to turn the visual expansion off in order to best view these items. When you create a probe by scoping a vertex, edge, face, or volume, the results reported for the probe are for the undisplaced nodes and elements. The displaced location of the probe (if any) is not used in any way to calculate results. If the probe is scoped to any suppressed parts, then the probe will not solve or evaluate results. This strategy exists to prevent numeric contributions from elements and nodes that are not scoped. Results Output Coordinate System Some probes such as the Directional Deformation probe allow the results to be calculated and displayed in a coordinate system of your choice. Some other probes such as a Spring probe allow results to be output only in a specific coordinate system. Refer to Orientation Coordinate System: entry under the “Characteristics” column in the probe tables (see links above) regarding what coordinate systems are allowed and what the default coordinate system is. You can use Orientation in the Details view of the probe to change the output coordinate system.

Note When the Orientation Coordinate System is Global Cartesian, the triad symbol is not displayed. The exception is for Torque probes in magnetostatic analyses, where the global triad is displayed and the direction vector is placed at the global origin.

Limitations of Geometry-Based Probes The following table shows the limitations of geometry-based Probe results. If you make incorrect selections in the Details view for any of the probes, all the probes under solution remain unsolved. Probe

Scope

Deformation

Vertices, Edges, Faces, or Volume

Stress Strain

1002

Must be Scoped to a rigid part

Components and Principals Result Selection invalid

All Result Selection invalid X

X

X

X

X

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Result Outputs Thermal Flux1 Flux Density

X

1

Flux Intensity

X 1

X

Velocity

X

Acceleration

X

Position

X 1

X

Angular Acceleration1

X

Angular Velocity

1 — Not supported in explicit dynamics analyses.

Probe Details View The following table describes the Probe Details view categories and properties. All Probes provide the same Details view categories, however, based on the probe type and/or how you specify the probe properties; the availability of the properties can differ. Category

Property Name and Description

Definition

Type This read-only property displays the selected type of probe. Location Method Sets the probe location. Based upon the probe type, Location Method options include: Geometry Selection Default setting, indicating that the probe is applied to a geometry or geometries (X, Y, Z points, edge/edges, vertex/vertices, face/faces, or body/bodies), which are chosen using a graphical selection tools. If you select a point using the Hit Point selection tool (see Graphics Toolbar), the read-only X,Y, Z Coordinate properties display and show the coordinate locations. Geometry: visible when the Location Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. Coordinate System Use this property to set the location according to a user-defined coordinate system. This choice displays a Location drop-down list where you pick the particular coordinate system. The X,Y,Z Coordinates of the location are also displayed. Coordinate System: Visible when the Location Method is set to Coordinate System. Provides a drop-down list of available coordinate systems.

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Using Results Category

Property Name and Description Remote Points Use this property to scope the probe to a remote point. Remote Points: Visible when the Location Method is set to Remote Points. Provides a drop-down list of available remote points. Boundary Condition This Location Method option is available for Force Reaction and Moment Reaction probes. Use this property to scope the probe to an existing boundary condition. Boundary Condition: Visible when the Location Method is set to Boundary Condition. Provides a drop-down list of available boundary conditions. Contact Region Use this property to scope Force Reaction and Moment Reaction probes to an existing contact region that you pick from a Contact Region drop down list. Contact Region: Visible when the Location Method is set to Contact Region. Provides a drop-down list of available contact regions. Beam Use to scope the probe to an existing boundary condition that you pick from a Beam drop down list. Beam: visible when the Location Method is set to Beam. Provides a drop-down list of available beams objects. Mesh Connection Use this property to scope the probe to an existing mesh connection in the tree. Mesh Connection: Visible when the Location Method is set to Mesh Connection. Provides a drop-down list of available mesh connection objects. Surface Use the scope to probe to a surface and study reactions on cutting planes. Surface: Visible when the Location Method is set to Surface. Provides a drop-down list of available surface objects. Geometry: This property corresponds to the Surface property when the Location Method is set to Surface. Select a geometry Body. Boundary Condition This property is available for a number of probe types. It provides a drop-down list of available boundary conditions that you use to scope the probe to.

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Result Outputs Category

Property Name and Description Orientation Sets the direction of the coordinate system specified by the Coordinate System described above. X coordinate A read-only property that displays X Axis value for the Coordinate System property. Y coordinate A read-only property that displays Y Axis value for the Coordinate System property. Z coordinate A read-only property that displays Z Axis value for the Coordinate System property. Summation Displayed only for Moment Reaction probes when Orientation is also displayed. Allows you to specify the summation point where the moment reaction is reported. • Centroid — the simple calculated average; unweighted by length, area, or volume. • Orientation System — the coordinate system you specified with the Orientation setting. By Harmonic Response Analysis Only. This property displays for the Force Reaction and Moment Reaction probes. Property options include: Frequency When this option is specified, a Frequency entry property and the Sweeping Angle property also display. Set When this option is specified, a Frequency entry property and the Sweeping Angle property also display. Maximum Over Frequency When this option is specified, the Sweeping Angle property also displays. Frequency of Maximum When this option is specified, a Frequency entry property and the Sweeping Angle property also display. Maximum Over Phase When this option is specified, the Frequency property and Phase Increment property also display.

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Using Results Category

Property Name and Description Phase of Maximum When this option is specified, a Frequency entry property and Phase Increment property also display. Extraction Displayed only for Force Reaction and Moment Reaction probes when the Location Method is set to Contact Region or Mesh Connection. Options for Contact Region Setting When the Location Method is set to Contact Region, options include: • Contact (Underlying Element) • Target (Underlying Element) • Contact (Contact Element) (Force Reaction Probe only) Options for Mesh Connection Setting When the Location Method is set to Mesh Connection, options include: Master or Slave. Orientation Method Only displayed for a Joint Probe. Options include Joint Reference System and User Specified.

Options

Result Selection The options for this property vary based on the selected type of probe. See the Overview and Probe Types section for additional information based on your desired probe type. Display Time End Time or Time Step. Spatial Resolution When edges, vertices, faces, or bodies are selected as the Geometry, this property displays. It allows you to calculate the maximum (Use Maximum) or minimum (Use Minimum) result values across the given geometry selection. Result Type This property provides a list of available results for a Joint Probe.

Results

This category provides read-only properties of result you select in the Result Selection or Result Type drop-down list. The Node ID is displayed if you used the Snap to mesh nodes feature.

Maximum Value Over Time

This category provides read-only properties that vary based on the probe type. They display maximum values of the results you select over time in stepped analysis.

Minimum Value Over Time

This category provides read-only properties that vary based on the probe type. They display minimum values of the results you select over time in stepped analysis.

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Result Outputs Category

Property Name and Description

Information

Based on the probe type, the following read-only result-based properties may be provided by this category. • Time • Load Step • Substep • Iteration Number • Surface Area

Note • When you set Location Method to Coordinate System, the probe traverses the primary axes to determine where the hits occur on the model. The hit closest to the origin of the coordinate system is used. This behavior is similar to placing a laser at the origin of the system and then shooting the laser sequentially along positive and negative direction of x, y, z axis. • Probe objects scoped to x, y, z picking locations (using the Hit Point selection tool) are achieved in such a way that a projection of the picked location in screen coordinates occurs onto the model based on the current view orientation, in other words, normal to the display screen onto the model at the picked location on the screen. If the geometry is updated, the update of the projection will follow the original vector that was established “behind the scenes” when the x, y, z pick was first made. Therefore the update of Probe objects scoped to x, y, z picking locations may not appear to be logical since it follows a vector that was established dependent on a view orientation when the original pick was made. • Probe animation for joints is only supported if there is at least one rigid body. • Probes are designed to work with geometry entities only. They are not intended to probe displacements on remote locations. • The details view of the probe shows either the maximum or the minimum result values but not both.

Surface Results If you have already defined a surface, you can view the surface results by first adding a standard result or user defined result, and in the Details view of the result object, setting Scoping Method to Surface, then choosing the name of the particular surface that you defined.

Note Surface results are not supported for models using periodic or cyclic symmetry. The Details view for a surface result contains an additional item called Average, which can be parametrized. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Results For example, average stress over the surface is given by: { ∫ Stress(X, Y, Z) dAREA} / {TOTAL_AREA} For some results, the Details view will also contain a Total quantity, such as Total Force, which also can be parametrized. The Total quantities are presented in the following table. Currently, if you desire a Total quantity for Heat Flux, Magnetic Flux Density, Current Density, or Electric Flux Density, you must choose a vector user defined result. Total Force (as integrated from principal stress vectors) is available to both standard and user defined results. Identifier

Result

Surface Integral

TFVECTORS

Heat Flux

Heat Rate

BVECTORS

Magnetic Flux Density

Magnetic Flux

DVECTORS

Electric Flux Density

Charge

JTVECTORS, JCVECTORS

Current Density

Current

SVECTORS (also see Vector Principals (p. 885))

Stress Tensor

Force

Interpolation of Data on a Surface For a given surface (such as the intersection of a cutting plane and a finite element mesh), Mechanical examines each element in the set of scoped bodies to determine if any element edge was intersected by the surface. A surface may intersect multiple edges of a finite element, so Mechanical maintains a list of all (x,y,z) points and all element IDs from the edge intersections. This set of intersection points is, in essence, a set of interpolation points.

For example, you request a normal x-axis stress result on the surface (that is, SX). For a given interpolation point (x,y,z) lying on an edge of an element, Mechanical finds the natural (or normalized) coordinates of the point within the element. Mechanical then interpolates the corner values of SX, using the natural coordinates and shape functions, to find a value for SX at (x,y,z).

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Result Outputs

Force and Moment Reactions For a pre-defined surface, a surface probe enables you to study reactions on cutting planes. You can extract generated member forces and reactions through a model by using a reaction probe scoped to a surface. For this probe type, you must explicitly select the bodies to be sliced. You cannot apply this to “all bodies.” You then specify for the Extraction detail whether you want to study nodes in front or behind the plane. The probe will only operate on elements cut by the plane (and only nodes on those elements which are on the selected side of the plane). Note that the surface probe will display nodal forces for all nodes that are involved in the reaction calculation.

Surface Displays and Fracture Mechanical analyzes for duplicates the sets of (x,y,z) for the facets in a surface construction object and compresses it by discarding all duplicate (x,y,z) sets. Mechanical employs compression to reduce the size of the data cache and to improve performance. For each remaining (x,y,z) in the surface, Mechanical derives via interpolation the results (like displacements and stresses) from precisely one element. That is, even if an (x,y,z) resides in many elements, Mechanical only fetches the displacements from one element. Hence, interpolated displacements at the (x,y,z) may currently fail to demonstrate the proper deformation of a crack.

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Using Results

Vector Plots Certain result items can be displayed using vectors such as the vector principal stresses or vector principal strain results. Similarly total deformation, total velocity and total acceleration can also be displayed using vectors. Using the Graphics button, you can display results as vectors with various options for controlling the display. See the Vector Display Context Toolbar (p. 64) section for more information.

Result Summary Worksheet The Worksheet summary feature displays quantities and a summary of results in tabular format. It provides minimum and maximum values, the associated units of measure, as well as time step values, including the time unit of measure. The Solution object provides a contextual (right-click) menu option, Worksheet: Result Summary, that allows you to access this display, as illustrated below.

For the results displayed by the List Result Summary option, each table entry provides the right-click option, Go To Selected Items In Tree, to select and then graphically display the corresponding result object.

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Result Utilities If a result is included in the tree but not yet evaluated, indicated by a yellow thunder bolt icon, the Worksheet displays a value of zero (note table entries above). Result types supported by this feature include: • Normal Contour/Vector type results such as Stress, Temperature, and Deformation. • User Defined Results. • Force and Moment Reaction Probes. • Joint Probes reporting Force or Moment. • Spring Probes. • Bolt Pretension Probes.

Result Utilities The following topics related to result utilities are covered in this section. Adaptive Convergence Animation Capped Isosurfaces Dynamic Legend Exporting Results Generating Reports Renaming Results Based on Definition Results Legend Results Toolbar Solution Combinations

Adaptive Convergence See the Adaptive Convergence (p. 1065) topic in the Understanding Solving section of the ANSYS Mechanical User’s Guide.

Animation The Animation feature displays in the Graph window when you select a result object in the Mechanical application. Here is an example of the Graph window with a result object selected.

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Using Results

The specific Animation functions are presented below. Control

Description Play: Initiates a new animation.

(same toolbar location as Play)

Pause: Pauses an existing animation. Choosing Play after Pause does not generate new animation frames. When the animation is paused, as you move the cursor across the graph, the cursor’s appearance changes to a double horizontal arrow when you hover over the current frame indicator. With the cursor in this state, you can drag the frame indicator to define a new current frame. The result graphic will update accordingly. Stop: Halts a result animation. Choosing Play after Stop generates new animation frames. Distributed: For static analyses, frames display linearly interpolated results. Frame 1 represents the initial state of the model and the final frame represents the final results calculated by the solver. For stepped and transient analyses, the frames in Distributed mode are distributed over a time range selected in the graph.1 (p. 1013) Result Sets: (available only for stepped and transient simulations) Frames represent the actual result sets that were generated by the solver.1 (p. 1013) Frame Markers: display what time points are being used in the animation by placing a vertical line at the time points. Select the number of frames in the animation. Select the desired amount of time for the entire animation.

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Result Utilities Control

Description Export Video File: Saves animation as an AVI file.

Note When exporting an AVI file, make sure that you keep the Mechanical module window in front of other windows until the exporting is complete. Opening other windows in front of the module window before the exporting is complete may cause those windows to be included in the AVI file capture.

Caution The Aero Theme display mode in Windows 7 is incompatible with the screen capture used in Mechanical. If you are running Windows 7, select a Basic Theme display mode to restore this capability. Damped Modal Animation: Turns on time decay animation of complex modes in a Modal Analysis (p. 196) that has damping applied. This button is not available (grayed out) for any of the following: • Any analysis type other than modal. • Any modal analysis whose Damped setting (under Solver Controls) is set to No. • Any modal analysis whose Damped setting is set to Yes, and whose Solver Type is set to Reduced Damped, and Store Complex Solution is set to No. Zoom to Fit Animation: When turned on, Mechanical loops through all the time steps to compute an auto scale factor that will accommodate the displacement for a full range of time steps and ensure that they will fit nicely in the screen. For more information on auto scale factors, see Result Context Toolbar (p. 59). When turned off, Mechanical uses the current result scale factor for animation. While this option results in increased animation speed, you may experience some distortion if the current display time has a displacement that is much smaller than the peak displacement through which the animation occurs. 1 — For stepped and transient simulations, as you move the cursor across the graph, the cursor’s appearance changes to a scope icon for solved solution points. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Results

Animation Behavior Depending upon the type of simulation that you perform, the behavior of the resulting animation varies. For a static simulation, the progression of an animation occurs in a linear forward/backward manner. The color contours begin with the initial condition, advance to the solution state, and then “rewinds” to the initial conditions. For transient and stepped simulations that have an associated time or step range, the animation begins at the initial time or step value, progresses to the final set, and then stops and starts at zero again. It does not traverse backward as it does for static simulations. As illustrated below, you may also select a specific time period to animate that is a subset of the total time. To do so, drag the mouse through the time period in the graph. The selected time period turns blue. Click the Play button to animate only through that period. While that specific period is playing, you can right-click the mouse to receive the options to Pause, Stop, or to Zoom To Range, which expands the defined period across the entire graph. The following demo is presented as an animated GIF. Please view online if you are reading the PDF version of the help. Interface names and other components shown in the demo may differ from those in the released product.

Note In a dynamic analysis, probe animation for joints is only supported if there is at least one rigid body. See Probes.

Capped Isosurfaces Capped Isosurface mode displays surface bodies through the geometry that correspond to a given value within the calculated range for a selected result. To view a capped isosurface, display the Capped Isosurface toolbar from the Mechanical application.

The value for the isosurface is set by the slider or textbox in the toolbar. The slider represents the range from min to max for the selected result. The three radio buttons control if any solid geometry remains visible on either side of the isosurface. The leftmost button displays the isosurface only, the center button displays the surface body and geometry with values below the surface body, the right button displays the surface body and values above.

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Result Utilities

Dynamic Legend The dynamic legend feature helps you display the result range and contour colors associated with the visible elements. You can use the dynamic legend feature when you slice a body or hide bodies in an assembly. When you apply the dynamic legend feature to a sliced body, Mechanical repositions the Min and Max annotations to the lowest and highest result values in the sliced body. For models that include multiple bodies the maximum and minimum result values can occur at the joined surfaces even if these surfaces are not visible.

To update the legend and view the result range for the visible elements: • Right-click the legend, and then click Adjust to Visible

Note The dynamic legend behavior is not applicable for Probe annotation. Adjusting the legend to visible elements updates the legend colors, values, and adds a Custom tag to the legend information. To restore the legend display for the entire body after you disable the slice or hide command: • Right-click the legend, and then click Reset All to view the result range for the entire body

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Using Results

Note If you do not reset the legend to show result range for the entire body after disabling the slice or hide command, Mechanical displays the out of range values with colors not included in the legend.

Exporting Results The data associated with result objects can be exported in Text (.txt) and Excel (.xls) file format by right-clicking on the desired result object and selecting the Export option. Once executed, you define a filename and then select the file type. An Excel file automatically opens providing the node numbers and the corresponding result data.

Exporting Node Results In addition to a general export of all result data, you can also manually select results for one or more nodes and export data for those nodes only. To export node results: 1. Select the desired result object. 2. Choose the Select Mesh option from the Select Type menu on the Graphics Toolbar. 3. Select a desired selection tool in the Select Mode menu (also on the on the Graphics Toolbar). The Vertex geometry selection option needs to be selected. It is the only selection option available to pick nodes. You may wish to review the Selecting Nodes section of the Help. 4. Select the desired nodes on the result plot.

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Result Utilities 5. In the graphics window, right-click the mouse and select Export Node Results. You are prompted to save the data in .txt format. You may also select to save the data as an Excel file. Once you save the file, an Excel file automatically opens providing the node numbers and the corresponding result data.

Note • Path Results, Surface Results, and Crack-based results do not support this feature. • Results scoped to elements or element-based named selections do not support this feature.

Generating Reports See the Report Preview (p. 22) section.

Renaming Results Based on Definition The option Rename Based on Definition is available when you right mouse click on any result (under Solution objects), or any Result Tracker (under Solution Information objects). When you choose this option, the Mechanical application automatically renames the result or Result Tracker based on the selected parts (for example, Temperature can be renamed to Temperature — Tube, or Directional Deformation can be renamed to Directional Deformation — All Bodies).

Results Legend By default the results legend displays the following information: Object Title This is the name of the selected tree object. Place your cursor over the legend and right-click the mouse to display the following options: • Named Legends: a name can represent the following data: – Number of contours – Color scheme – Color overrides per band – Value break per break, either automatic or numeric Use the Named Legends option to create new named legends or to manage existing ones that can be edited independently. See the steps shown below. • Vertical: view the result contours color spectrum vertically (default). • Horizontal: view the result contours color spectrum horizontally. • Date and Time: toggle Date and Time on and off. • Max, Min on Color Bar: shows extremes when checked. If unchecked, they appear in the title book. • Logarithmic Scale: displays result values.

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Using Results • All Scientific Notation: displays result values. • Digits: specifies the number if significant digits for result values. The default is 3. Options include 2 through 8. • Independent Bands: Use to set the alarm color representing the maximum/minimum contour range. The following choices are available: – None (default) – Top – Bottom – Top and Bottom • Color Scheme: used to change the color spectrum. The choices available are: – Rainbow (default) – Reverse Rainbow – Grayscale – Reverse Grayscale – Reset Colors • Semi transparency • Adjust to Visible • Reset All Type The result type of the selected tree object. Units A display of the current Unit system Time The current solution time step for the result. Time Stamp The time that the result was solved.

New Named Legends By selecting New, an input dialog box displays to specify a name. Future edits use this new name. You can create an independent variation of a named legend by choosing Unnamed or New. The option Unnamed is the default. The Unnamed option indicates that the legend can be edited independently.

Managing Named Legends The Named Legends dialog box allows you to manage styles. Options included:

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Result Utilities • Import • Export • Rename • Delete Checked named legends appear in the legend context menu by default for new databases only.

Maximum/Minimum Contour Range If the context menu is displayed from a color band instead of the title bar, the following items appear at the top of the menu, followed by a separator: • Custom Color: a pop-up color appears when you right click a color band. The same color can be used for more than one band. • Automatic Color: the default color is restored. By hovering your mouse over the contour values in the maximum/minimum contour range, you edit the highlighted information. Two items appear at the top of the context menu: • Edit: You can enter a custom value in the field at the top of the contour provided it is greater than the default value calculated by the program. • Automatic Value: The value calculated by the program. You can set the number of bands between the bottom and top of the contour using the + or – buttons. The number of bands can range from 4 to 14.

Note When the distance between adjacent bands is very small (thousandth of the entire range), the contour colors may not correctly reflect the ranges in the legend.

Results Toolbar Refer to the Result Context Toolbar (p. 59) section under Context Toolbar (p. 53).

Solution Combinations You can create solutions that are calculated from other solutions. These are derived from the addition of results coming from one or more environments, each of which can include a multiplication coefficient that you supply. Included are nonlinear results, which are a simple addition of values. The calculated values cannot be parameterized.

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1019

Using Results The Design Assessment system provides a more powerful Solution Selection capability, allowing you to combine results from a greater variety of upstream analysis systems and perform additional post processing functions using external scripts.

Note Choosing Update Project from the Project Schematic will not solve a Solution Combination in the Mechanical application. To Create a Solution Combination Object You can insert one or more Solution Combination objects under the Model object. Under the Solution Combination object, you can add the following results types: • Stress Tool • Fatigue Tool • Contact Tool (for the following contact results: Frictional Stress, Penetration, Pressure, and Sliding Distance) • Beam Tool • Beam Results • Stresses • Elastic Strains • Deformations Each solution object contains its own configuration spreadsheet, available through the Worksheet View.

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Result Utilities When setting up a Solution Combination, you select the Environment Objects you wish to add together from a drop-down list of all available environments. At least one environment must be checked. Enter the multiplication coefficient you wish for each environment. The results values shown for these objects are derived from the same results objects in the referenced environments, including any defined multiplication coefficients. The basic formula for calculating the results is: (multiplication coefficient 1 X value from environment 1) + (multiplication coefficient 2 X value from environment 2) + etc.

Note You can specify a coordinate system in the Details view of the Solution item for which you request a solution combination. The default is the Global Cartesian Coordinate system. The solution item at each result set identified in the Worksheet view is calculated in the specified coordinate system and then solution combination is carried out. If you request solution combination for derived quantities such as equivalent/principal stresses as well as total displacement, the following two step procedure is used: 1. Solution combination is carried out to compute component results first. 2. The requested result items are then derived from the components. In addition: • Equivalent strains (including elastic, thermal, plastic, creep, total, and total plus thermal equivalent strains) are read from the result file and are used directly in the linear combination formulation. The component strains (X, Y, Z, XY, YZ, XZ) are not used. This procedure is similar to using the MAPDL SUMTYPE,PRIN command. • Using the equivalent strains from the result file may lead to unexpected (or even negative) results.

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Understanding Solving The overall procedure for obtaining a solution in the Mechanical application is as follows: 1. Specify the solver type and other settings as applicable in the Details view of the Analysis Settings object. 2. For background solving capabilities other than My Computer, Background, use RSM Administration to configure servers and queue. This step may be done for you by a person designated as the RSM administrator. 3. For solving capabilities other than standard My Computer options, create solve process settings to utilize the queue created in step 2. The appropriate solve process settings (for example Solve Manager and Queue) for your computing environment may be provided by your RSM administrator. 4. Initiate the solve. You can simply click on the Solve button to use the default solve process settings or display the drop down menu to select specific solve process settings.

• To solve all analyses, highlight the Project object, then choose Solve. • To solve all analyses for a model, highlight the Model object, then choose Solve. • To solve a particular analysis, highlight any of the following objects, then choose Solve: – The particular analysis object (for example, Static Structural). – The Solution object. – Child objects of the Solution object. If you initiate a background solve, and the project has not been initially saved, you will be prompted to save the project first.

Note For a background solve process setting, you still see the Meshing dialog box because meshing will first be run locally and in synchronous mode before the solve is sent to the queue. Meshing locally allows the same mesh to be used in each solve if multiple Solutions are being solved simultaneously under a single Model, rather than re-meshing for each solve. For both synchronous and background solves, you can check your mesh before solving through a right mouse click on the Mesh object and selecting Preview Mesh in the context menu.

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1023

Understanding Solving A Solution Status window in the Mechanical application monitors solution progress for synchronous solutions. Conventional progress bars are displayed in this window along with a Stop Solution button and an Interrupt Solution button. You have two choices when halting the progress of the Mechanical APDL solver in the Solution Status window. If you would like the solver to halt immediately and forego writing any outstanding restart points, click the Stop Solution button. If, instead, you would like to allow the solver to complete its current iteration and record outstanding restart points, click the Interrupt Solution button (available for static structural and transient structural analyses). Neither case affects previous restart points.

Note When running a solution in the background, the RMB option Disconnect Job from RSM is available from the Solution folder. The option becomes visible once you submit the job to the RSM. This option disconnects mechanical from the RSM job and the application returns to the beginning of the solution process. You cannot disconnect the job while it is running.

Note If you are familiar with Mechanical APDL functionality, clicking the Interrupt Solution button places a file named file.abt in the working directory. Any error messages are displayed in the Messages window immediately after attempting the solution. If you interrupt the solution, a confirmation message is displayed in the Messages window. When a solution is in progress in the Mechanical application, you can freely access the Engineering Data tab and review data. The engineering data used in the solution will be in read-only mode as indicated by a lock icon. The following characteristics apply to background configurations where the RSM user interface is used to monitor solutions: • While a background solution is in progress for a branch, that branch will be in a read-only state with the exception that result objects can be deleted during this time. Other branches can be edited freely. • You can cancel a running job and reset the state of the tree by selecting Solution in the tree and choosing Stop Solution in the context menu (right mouse button click). Note that this will immediately kill the job and not attempt to bring back any solver files (if solving on a compute server). Use Evaluate Results or Retrieve first if you wish to bring back any files from the server. • An alternative to canceling a job is to choose Interrupt Solution in the context menu. As in a synchronous solution, this will allow the solver to complete its current iteration and record outstanding restart points. • A green down arrow status symbol indicates that a solution is ready for download and/or loading into the Mechanical application. This does not indicate the success or failure of a solve. • When the green down arrow is displayed to indicate results are ready for download, choose Get Results from the context menu to perform the download, if necessary, and load results into the Mechanical application. In the event of a network connection loss to the Remote Solve Manager, the Get Results function prompts you with a warning message to address the connection issue. You can perform the Get Results operation and retrieve your results information once the you re-establish a connection.

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Solve Modes and Recommended Usage If you do not wish to retrieve your results, simply select Disconnect Job from RSM from the RMB context menu as described above.

Note When using a Local solve process setting and a solve is in progress, do not reboot or log off the Windows client machine. If you reboot or log off, the connection to the Linux job will be lost and results will not be retrievable. If the Linux job has completed, then rebooting or logging off is safe. The mathematical model is applied and the results are evaluated. When the compute server is a remote machine, the model is applied and results are evaluated on that machine. You can rename Solution or Solution Information objects and items under these objects using a right mouse button click and choosing Rename. You then type a new name for the object (similar to renaming a file in Windows Explorer). If you are using a The Mechanical Wizard (p. 123), you must be sure that all the tasks in the wizard are complete (

) before you try to solve.

To view your solution, select View Results from the The Mechanical Wizard (p. 123). Or, click the result and the solution appears in the Geometry Window (p. 20) window. You can use the postprocessing features during solve when the solve process is on a remote computer or as a background process.

Related Solving Topics Solve Modes and Recommended Usage Using Solve Process Settings Solution Restarts Solving Scenarios Solution Information Object Postprocessing During Solve Result Trackers Adaptive Convergence File Management in the Mechanical Application Solving Units Saving your Results in the Mechanical Application Writing and Reading the Mechanical APDL Application Files Converting Boundary Conditions to Nodal DOF Constraints (Mechanical APDL Solver) Resolving Thermal Boundary Condition Conflicts Resume Capability for Explicit Dynamics Analyses Solving a Fracture Analysis

Solve Modes and Recommended Usage Workbench includes capabilities for efficiently solving various kinds of analyses taking CPU usage and solving time into consideration. The following table defines the various solve “modes” available and includes references to recommended usages and associated solve process settings. Further details are discussed in the various other sections under «Understanding Solving» (p. 1023).

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Understanding Solving Solve Start Mode

Solve Monitor Mode

Recommended Usage

Solve Process Settings

In Process — The solve starts and finishes on your computer in the directory where your project resides.

Synchronous The solve runs and finalizes within the same Workbench session.

Analyses that are not expected to be extremely CPU intensive.

Out of Process — The solve starts and finishes either on another computer, or on your computer but in a directory that is separate from the one where your project resides.

Asynchronous — The solve is not restricted to run and finalize during any particular Workbench session.[2 (p. 1026)]

Analyses inMy Computer, Backvolving large ground models or a large amount of processing time and machine resources, excluding linked analyses and analyses that involve multiple convergence loops.[3 (p. 1026)]

Yes

Synchronous The solve runs and finalizes within the same Workbench session.

Analyses involving large models or a large amount of processing time and machine resources, including linked analyses and analyses that involve multiple convergence loops.

Yes

My Computer

My Computer, Background, then click Advanced… button and check Solve in synchronous mode (ANSYS only).

Remote Solve Manager (RSM) Involvement No[1 (p. 1026)]

[1] — Exceptions are the Rigid dynamics and Explicit Dynamics solvers. Both solvers user RSM for the In Process mode. [2] — When solving in asynchronous mode, you are free to continue working independently of the solve job, or close the Workbench session and retrieve the solution results at a later time. You can even shut down your computer when using a Solve Manager located on another computer (See RSM Administration and Using Solve Process Settings (p. 1027)). An asynchronous solution is queued with other solutions and can run either on your local machine or on a more powerful remote machine. Background solutions are recommended for large models or simulations that require a large amount of processing time and machine resources. Sending the Solve to a remote computer can increase productivity when a highend server is available on your network. [3] — Though not recommended for a linked analysis using this solve mode combination, you can solve a linked analysis or an analysis involving multiple convergence loops provided you solve each analysis separately, that is, you must obtain the first solution, then choose Get Results from the context menu in the first analysis before obtaining the solution in the second analysis. The Out of Process and Synchronous mode combination is recommended for these types of analyses because the solve can occur 1026

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Using Solve Process Settings from a single user action. Also, asynchronous solutions involving linked analyses that are initiated from the Project Schematic by choosing Update will automatically achieve the same effect as choosing Get Results, thus providing another method for solving linked analyses from a single user action. See the Understanding Solving help section for additional information.

Using Solve Process Settings Solve process settings are individual solving configurations that you set up prior to initiating solves. Settings include specifying a synchronous or background solve, as well as solve manager machine and queue designations for background configurations. Using the Solve Process Settings dialog box, you can: • Add a local solve process • Add a remote solve process • Specify a default solve process • Modify existing solve process settings • Delete an existing solve process • Rename a solve process You access the Solve Process Settings dialog by selecting the Solve Process Settings option from the Tools menu in the Mechanical application window. The dialog displays as illustrated below based on your solve process selection. My Computer: The is the default setting. When using this setting, the application solves and finalizes the solution on the local computer in the current Workbench session.

My Computer, Background: selecting this setting, solves on the local machine but is not restricted to finalizing in a particular Workbench session. You need more than one solver license to use this setting. However, you can perform Rigid Dynamics and Explicit Dynamics analyses with one solver license by selecting the Use Shared License, if possible option on the Advanced Properties dialog box. The solve process in red indicates that the process is selected as the default solve process and persists across Workbench sessions.

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Understanding Solving

Solve Process Options Add Local

Adds a new local Solve process. The solve manager for this type of solve process is My Computer and cannot be changed.

Add Remote

Adds a new process, where you can specify the remote computer you want to use.

Set As Default

Specifies the solve process as Default across workbench sessions.

Rename

Renames the selected solve process.

Delete

Deletes the selected solve process.

Note You must have a unique name for each Solve process.

Solve Process Settings Computer Settings Solve Manager

Specifies the name of the Solution Manager machine. The manager machine is configured with queues and compute servers.

Note or local configurations, Solve Manager is automatically set to My Computer and cannot be modified. Queue

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Specifies the name of the queue configured using RSM Administration. If this list does not contain any queues, check that RSM is installed for the computer specified in the Solve Manager field.

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Using Solve Process Settings Specifies the name of a valid ANSYS product license (ANSYS Professional or higher) to be used for the solution on the server.

License

Note • You must specify a valid ANSYS product license (ANSYS Professional or higher) because a separate instance of an ANSYS application is being used. • The license from your current ANSYS Workbench client session cannot be accessed from the remote ANSYS application executable.

Note • Computer Settings are not available when you select the built-in My Computer solve process. • Solve Manager and Queue fields are required for all local and remote background configurations.

Advanced Properties Selecting the Advanced button on the Solve Process Settings dialog displays one of the following Advanced Properties dialog boxes. The available options are based on whether you select My Computer or My Computer, Background.

My Computer

My Computer, Background

The Advanced Properties are described below.

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Understanding Solving Distribute Solution (if possible)

Enables a distributed solution.

Note Supported only for static, buckling, transient, modal, full harmonic, and explicit dynamic analyses. Max number of utilized processors

Sets the number of processors to use during solution. The default is 2. Entering 0 does not send any request to the Mechanical APDL solver related to the number of processors to use. If you specify a number greater than the number of processors in the computer, the highest available number of processors is used. This setting is applicable for both shared-memory and Distributed ANSYS solutions. See this section from the Mechanical APDL help for more information: HPC License in the Parallel Processing Guide. For Explicit Dynamics analyses, this setting is used to determine the number of processors unless this has been specified in the Additional Command Line Arguments.

Note • Available only for Mechanical APDL and Explicit Dynamics solver. • You need an ANSYS Mechanical HPC license for each processor after the first two. • For Explicit Dynamics analyses, this setting is used to determine the number of processors unless this has been specified in the Additional Command Line Arguments.

Use GPU Acceleration (if possible)

Provides access to the Graphics Processing Unit (GPU) acceleration capability offered by Mechanical APDL, including support for the NVIDIA and Intel acceleration cards. To enable this feature, you must select NVIDIA or INTEL from the drop-down menu.

Number of utilized GPU devices

Specifies the number of GPU accelerator devices to be used when the Use GPU acceleration property is set to use a valid accelerator type. This value can be an integer in the range of 1 to 20. The default value is 1. For additional information, see the GPU Accelerator Capability section of the Mechanical APDL Parallel Processing Guide.

Manually specify Mechanical Helps you specify the amount of system memory, in MB, used for APDL solver memory settings the ANSYS application workspace and database.

Note Applicable to Mechanical APDL solver only.

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Using Solve Process Settings Additional Command Line Arguments

Specifies arguments that you would normally enter into a command line input, for example, -machine option for a distributed solution.

Custom Executable Name (with path)

Specifies a custom ANSYS application solver executable name and path. This executable will be used for the ANSYS application solve rather than using the default.

Manually specify Linux settings

Enter a valid User Name and Working Folder to override the RSM compute server proxy settings.

Note • You must have write access to this folder on all potential compute proxies in the queue. • To use the RSM settings, leave this field blank.

Use Shared License, if possible

Enables the use of a Shared License

Note • This option works only for Explicit Dynamics and Rigid Dynamics analysis. For more information, see Shared Licensing • License sharing is only possible within a single Workbench session with the solver running on the same machine. A remote solve on another machine via RSM will require a license for the Workbench session and a license for the remote solve.

License Queuing: Wait for Available License

Instruct the MAPDL solver to wait for an available license when solving remotely via RSM.

Solve in synchronous mode (Mechanical APDL solver only)

Select to mimic the default My Computer behavior while leveraging the computation power of a remote machine. See this section from the Mechanical APDL help for more information: HPC Licensing in the Parallel Processing Guide. For Explicit Dynamics analyses, this setting is used to determine the number of processors unless this has been specified in the Additional Command Line Arguments.

Note • Applicable only for Mechanical APDL solver. • Requires an additional license.

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Understanding Solving multiple convergence loops automatically on a single click of the Solve button. This is the default and allows the user to close the Mechanical editor or solve an unrelated analysis. See the Understanding Solving help section for additional information. OK — Commits all changes in the Solve Process Settings dialog box and closes the dialog box. You must choose OK for the Solve Process Setting configurations to be used when you initiate the solve. Cancel — Closes the dialog box and ignores all changes.

Note In order to run a distributed Explicit Dynamics solution on Linux, you must add the MPI_ROOT environment variable and set it to the location of the MPI software installation. It should be of the form: {ANSYS installation}/commonfiles/MPI/Platform/{version}/{platform} For example: usr/ansys_inc/v150/commonfiles/MPI/Platform/9.1/linx64

Solution Restarts Note Solution Restarts are supported in Static Structural and Transient Structural analyses only. However, they are not supported in a Static Structural analysis when computing fracture parameters. See the Computation of Fracture Parameters discussion in the Solving a Fracture Analysis section for more information. The solution process is composed of a sequence of calculations that predict a structure’s response when applied to a specific analysis type and loading condition. Restarts provide the ability to continue an initial or existing solution which can save time during the solve phase. This feature facilitates a variety of workflows, which include: 1. Pausing or stopping a job to review results and then restarting the job. 2. Review and correction of a non-converging solution. Solution parameters in the analysis settings could be fine-tuned or adjusted allowing the solution to proceed while retaining prior solution progress. Similarly a load history can be modified to aid in the convergence. 3. Extending a solution that has already completed, for example, to allow system transients to progress further into time. 4. Submitting post processing instructions into Mechanical APDL after the model has been fully solved (see below). The following topics are covered in this section: • Restart Points (p. 1033) • Generating Restart Points (p. 1033)

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Solution Restarts • Retaining Restart Points (p. 1033) • Viewing Restart Points (p. 1034) • Using Restart Points (p. 1034) • Deleting Restart Points (p. 1035) • Modifications Affecting Restart Points (p. 1035) • Loads Supported for Restarts (p. 1039) • Solution Information Files During Restart (p. 1039)

Restart Points Solution restarts are based on the concept of a restart point. Each restart point can be considered as a snapshot of the system solution state at a discrete point along the sequence of calculations. The solver stores this state of the solution in a restart file on disk. Every restart file on disk will have a corresponding restart point in the Mechanical GUI. See Viewing Restart Points (p. 1034) below. A solution can only be restarted from an available restart point. It is thus important to understand how to work with these restart points.

Generating Restart Points Restart points are automatically created by Mechanical depending on the analysis type. The program controlled option will create one restart point at the last successful solve point for a nonlinear analysis. However, you may directly control their frequency to alter the balance between flexibility and disk usage with the Restart Controls (p. 644) group of the Analysis Settings object. Restart points could be generated at all substeps or specific substep intervals in the analysis or at none at all.

Note • You can manually interrupt a solution and preserve any restart points that may have been produced from a converged iteration by clicking the Interrupt Solution button on the Solution Status window. • A stand-alone linear analysis will not produce any restart points with the program controlled option. It has to be explicitly turned on using the manual setting. However, if the analysis is linked to a follow on modal analysis, it will generate restart points by default.

Retaining Restart Points An incomplete solution (for example, a convergence failure) will always retain the restart points. However, for a complete solution, this is controlled by Retain Files After Full Solve property located in the Details view of Analysis Settings under Restart Controls. This property is set to No by default and hence will delete all restart points after the solution is completed. It can be set to Yes which will retain the restart files for the current project. Alternatively, there is a global option to control the restart points after a successful solve Tools> Options> Mechanical> Analysis Settings and Solution> Restart Controls and it applies to all projects.

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1033

Understanding Solving

Viewing Restart Points Once restart points are generated, they will be visible in several forms. For an overview, select the Analysis Settings object and refer to the Graph window where restart points are symbolized by triangular markers atop the timeline. The Tabular Data window lists the restart points within each load step. A restart point is color coded to distinguish between replayable and a non-replayable. A replayable solution is one which will produce the exact solution when run from start to finish or completed incrementally using intermediate restart points. A blue triangle indicates a replayable restart point. A red triangle indicates a potentially non-replayable restart point and can only be used in manual mode.

Note The Initial Restart Point does not represent a restart file on disk. It is only a place holder to facilitate selection to run the solution from the beginning even when other restart points are available.

Using Restart Points You can manually choose the restart point to be used in a solution. Alternatively, you can configure Mechanical to suggest one for you. To allow Mechanical to automatically select a restart point, set Restart Type to Program Controlled. If you prefer a different point, you may specify it directly by setting Restart Type to Manual and by: • Choosing Current Restart Point in the Details view of the Analysis Settings object. • Selecting the desired marker on the Graph window and choosing Set Current Restart Point in the context menu. • Selecting the desired cell in the Tabular Data window and choosing Set Current Restart Point in the context menu.

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Solution Restarts The Current Restart Point in the Restart Analysis group of the Analysis Settings object will indicate which restart point will be used the next time a solution is attempted. The current restart point in the graph/timeline window will be denoted with a double triangle in the timeline. The program controlled setting takes a conservative approach to guarantee a replayable solution and will always select the last replayable restart point. In manual mode, the software will not automatically change the current restart point and has to be selected explicitly. Picking a non-replayable restart point in manual mode is only recommended for experienced users who understand the implications of the results produced. Mechanical automatically tracks how restart points are affected as you work and modify your model. So they may get flagged as non-replayable (red triangle) or be removed altogether depending on the operation. See Modifications Affecting Restart Points (p. 1035) for details. Also see Restart Analysis (p. 644) under «Configuring Analysis Settings» (p. 635).

Note • An analysis should use the same units (set at the beginning of a solve) throughout the solve including all restarts. If the units are changed at any restart point, the solve is aborted and an error message is displayed. • Named Selections created/modified following the solution process are not recognized during a restart. For example, you may wish to list the nodes of a newly created Named Selection using the Command feature. Because the Named Selection’s geometric data was not defined during the initial solution process, no data is available for the command to process.

Deleting Restart Points In order to delete existing restart points, you may use the Delete All Restart Points in the context menu at the Environment and Solution folders. For more granularity, one or more restart points may also be deleted by selecting them on either the Graph or Tabular Data windows and issuing Delete Restart Points.

Note The Clear Generated Data option in the context menu from either the Solution, Environment, Model or Project objects also deletes all restart points.

Modifications Affecting Restart Points The following table summarizes the effects of making changes to the controls of the Analysis Settings object and the impacts on restart points.

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1035

Understanding Solving If a change is made to one of the following Controls…

Then… All Restart Points are Deleted

Current Restart Point is Set to Initial

Non-replayable Restart Points may be Available2

Current Restart Point set to the Beginning of the Modified Load Step

Step End Time3

X

Auto Time Stepping

X

X

Define By

X

X

Carry Over Time Step

X

X

Time Integration

X

X

Step Controls

Solver Controls

X

Rotordynamics Controls

X

Restart Points are Unaffected

Restart Controls

X

Restart Analysis

X

Non Linear Controls

X

Output Controls4

X

Stress

X

Strain

X

Nodal Force

X

Contact Miscellaneous

X

General Miscellaneous

X

Store Results At Damping Controls

X

X

X

Analysis Data Management

Save MAPDL dB

X

Delete Unneeded Files Solver Units

X X

The following table summarizes the effects of step modifications on restart points. If a change is made to one of the following Controls…

Then…

All Restart Points are Deleted

Current Restart Point is set to the Beginning of the Modified Load Step

Non-replayable Restart Points may be Available2

Activate/Deactivate

X

X

Add Step/Insert Step

X

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Solution Restarts Delete Step

X

A solution can be restarted after modification to the load history. However, any other changes to the definition delete all of the Restart Points.

Note • Displacements, Remote Displacements, and Nodal Displacements only support Tabular data modifications. See the Loads Supported for Restarts (p. 1039) topic for a detailed list. • Changing a Displacement boundary condition may cause the program to return to the initial restart point, depending upon the change you make. The restart point where the change occurred is maintained — not deleted. For example, changing the magnitude of either of these loads from a zero value to a non-zero value, or vice versa, prompts the application to return to the beginning of the solution process. Similarly, if you change the independent time value of either load, the solution process restarts from the beginning.

If a change is made to one of the following Controls…

Then…

Current Restart Point is Set to Initial1 Modify Load History

Constant

Current Restart Point is set to the Beginning of the Modified Load Step

X

X

Tabular Function Change Load Type (Constant, Tabular, Function)

Non-replayable Restart Points may be Available2

X

X

X

X

X

X

The following table summarizes the effects of adding/modifying/deleting a Commands object. When Restart Points are available, adding a new Commands object defaults to the last step so as to preserve the Restart Points. Adding a Commands object without Restart Points defaults to first step. If a change is made to one of the following Controls…

Then…

All Restart Points are Deleted Add/Modify/Delete Command Snippets

Under Environment

Current Restart Point is set to the Beginning of the Modified Load Step

Non-replayable Restart Points may be Available2

X

X

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Restart Points are Unaffected

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Understanding Solving If a change is made to one of the following Controls…

Then…

All Restart Points are Deleted

Current Restart Point is set to the Beginning of the Modified Load Step

Non-replayable Restart Points may be Available2

Restart Points are Unaffected

Under Solution/Results Under Model/Trunk Objects

X

X

Modifications such as adding or changing boundary conditions (for example, scoping changes), constraints, initial conditions, or editing model level objects (Geometry, Contact Region, Joint, Mesh) invalidates and deletes existing Restart Points. The exception is Direct FE loads with a zero magnitude Restart Points are retained. If a change is made to one of the following Controls…

Then… All Restart Points are Deleted

Add/Delete Boundary Condition Add/Delete Direct Boundary Condition

Restart Points are Unaffected

X Force (zero)

X

Force (non zero)

X

Displacement

X

Model Level Changes

X

1

Restart Type specified as Program Controlled.

2

It can only be selected when Restart Type is specified as Manual.

3

When the Step End Time option in the Step Controls category is changed, the restart point is deleted as well as all the steps after this modified restart points are deleted and are not available, not even for manual restarts. Exception is the case when Fluid Solid Interface load exists and all the restart points are retained. 4

It is recommended that you not change Output Controls settings during a solution restart. Modifying Output Controls settings changes the availability of the respective result type in the results file. Consequently, result calculations cannot be guaranteed for the entire solution. In addition, result file values

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Solution Restarts may not correspond to GUI settings in this scenario. Settings turned off during a restart generate results equal to zero and may affect post processing of results and are therefore unreliable.

Note Restart is not supported for an analysis with Adaptive Convergence. So the presence of an adaptive convergence will not retain any restart points.

Loads Supported for Restarts The following table outlines which loads may be modified for a solution restart. Load Specified As… Load Type

Constant

Tabular

Function

Pressure

X

X

X

Line Pressure

X

X

X

Force

X

X

X

Remote Force

X

X

X

Moment

X

X

X

Displacement

X

X

N/A

Remote Displacement

X

X

N/A

Rotational Velocity

X

X

X

Bolt Pretension

X

X

N/A

Acceleration

X

X

X

Earth Gravity

N/A

N/A

N/A

Hydrostatic Pressure

X

N/A

N/A

Bearing Load

X

X

N/A

Joint Load

X

X

X

Pipe Temperature

X

X

X

Pipe Pressure

X

X

X

Thermal Condition

X

X

X

Imported Load

N/A

N//A

N/A

Nodal Force

X

X

X

Nodal Pressure

X

X

X

Nodal Displacement

X

X

N/A

Solution Information Files During Restart During a restart, solution information files (input file ds.dat and output file solve.out) from the previous solve are retained for reference by renaming it just before the restart solve is initiated. The naming convention is filename_loadstep_substep.ext. For example, if the previous solve occurred at loadstep = 2 and substep = 5, the file name would be ds_2_5.dat and solve_2_5.out. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

1039

Understanding Solving Files from the initial solve will be named ds_0_0.dat and solve_0_0.dat. Based on the restart point, Mechanical will ensure that obsolete and invalid solution files are cleaned up.

Solving Scenarios This section describes the various configuration steps involved for the following solving scenarios: • Solve on the Local Machine within the Workbench process (synchronous) (p. 1040) • Solve on My Computer in the Background (asynchronous) (p. 1040) • Solve Directly from My Computer to a Remote Windows Computer (p. 1040) • Solve Directly from My Computer to a Remote Linux Computer (p. 1041) • Solve to a Windows Compute Server via a Solve Manager Running on Another Computer (p. 1041) • Solve to a Linux Compute Server via a Solve Manager Running on Another Computer (p. 1042) • Solve to LSF Cluster with Remote Solve Manager (p. 1042) • Solve to Microsoft HPC Cluster with Remote Solve Manager (p. 1042)

Solve on the Local Machine within the Workbench process (synchronous) • Use the built-in My Computer solve process setting.

Solve on My Computer in the Background (asynchronous) • Use the built-in My Computer, Background solve process setting. The option is only functional if Remote Solve Manager (RSM) was installed along with Workbench. RSM has a built-in “Local” queue and server for running jobs on the client computer.

Solve Directly from My Computer to a Remote Windows Computer This step requires the following configuration steps: 1. The Mechanical application and RSM must also be installed on both your local computer and the remote Windows Computer. 2. For the (My Computer) Solve Manager on your local machine: • Create a remote Compute Server. (This is the remote Windows machine). For details, see Adding a Compute Server in the RSM documentation. • Create a Queue and add the remote Compute Server to the Queue. For details, see Creating a Queue in the RSM documentation. The job will run under the currently logged in user account on the remote computer. 3. Create a Local solve process setting (see Using Solve Process Settings (p. 1027)). After creating the solve process setting, select the local queue created in step 2. 4. Use the Solve Process Setting created in step 3 using the Solve drop down button on the toolbar.

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Solving Scenarios

Solve Directly from My Computer to a Remote Linux Computer This step requires the following configuration steps: 1. Configure a Linux machine for native mode communications. (In native mode, RSM is installed and running locally on the remote Linux machine that serves as the remote Compute Server Proxy, so a separate protocol isn’t required for Windows-to-Linux communications.) See Configuring RSM to Use a Remote Computing Mode and Configuring Native Cross-Platform Communications for details. 2. For (My Computer) Solve Manager on your local machine: • Create a remote Compute Server. (This is the remote Linux machine). For details, see Adding a Compute Server in the RSM documentation. • Create a Queue and add the remote Linux Compute Server to the Queue. For details, see Creating a Queue in the RSM documentation. 3. Create a Local solve process setting (see Using Solve Process Settings (p. 1027)). After creating the solve process setting, select the queue created in step 2. 4. Use the Solve Process Setting created in step 3 using the Solve drop down button on the toolbar.

Solve to a Windows Compute Server via a Solve Manager Running on Another Computer This scenario requires the following configuration: 1. Open the RSM user interface window from the Start menu or double-click on the tray icon ( ) if it is already running. Under Tools> Options add the Solve Manager machine (that is, the remote machine that was configured with Servers and Queues). The Solve Manager will appear in the tree view. This step will allow you to monitor jobs sent to that Solve Manager.

2. Create a Remote solve process setting (see Using Solve Process Settings (p. 1027)). You will enter the same machine name that you used in step 1. You will then be able to select the appropriate queue from the drop down list. 3. Select the Solve Process Setting created in step 2 on the Solve drop down button on the Mechanical application toolbar.

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Understanding Solving

Solve to a Linux Compute Server via a Solve Manager Running on Another Computer This scenario requires the following configuration: 1. Open the RSM user interface window from the Start menu or double-click on the tray icon ( ) if it is already running. Under Tools> Options add the Solve Manager machine (that is, the machine that was configured with Servers and Queues). The Solve Manager will appear in the tree view. This step will allow you to monitor jobs sent to that Solve Manager.

2. A Queue with a Server pointing to the target Linux machine must be configured in the Solve Manager (See RSM Administration). Remember, in this case the Linux machine is a proxy for a Windows-based computer. As far as RSM knows, the job is running on the Windows machine. 3. Create a Remote solve process setting (see Using Solve Process Settings (p. 1027)). You will enter the same machine name that you used in step 1. You will then be able to select the appropriate queue from the drop down list. 4. Select the solve process setting created in step 3 from the Solve drop down button on the Mechanical application toolbar.

Solve to LSF Cluster with Remote Solve Manager The configuration from a Mechanical application user perspective is the same as above. A Solve Process Setting is required that specifies a local or remote RSM Solve Manager and Queue where the Solve is submitted. See Integrating Windows with a Platform LSF cluster in the RSM documentation for configuration details.

Solve to Microsoft HPC Cluster with Remote Solve Manager The configuration from a Mechanical application user perspective is the same as above. A Solve Process Setting is required that specifies a local or remote RSM Solve Manager and Queue where the Solve is submitted. See Integrating with Mircosoft HPC in the RSM documentation for specific configuration details.

Solution Information Object You can track, monitor, or diagnose problems that arise during any solution as well as view certain finite element aspects of the engineering model, using a Solution Information object, which is inserted automatically under a Solution object of a new environment or an environment included in a database

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Solution Information Object from a previous release. You can also manually insert a Solution Information object under a Connections object for solver feedback. When you select a Solution Information object in the tree, the following controls are available in the Details view under the Solution Information category: • Solution Output: [not applicable to Connections object] Determines how you want solution response results displayed. All of the options are displayed in real time as the solution progresses: – Solver Output (default): Displays the solution output file (text) from the appropriate solver (for example, the Mechanical APDL application, AUTODYN). This option is valuable to users who are accustomed to reviewing this type of output for diagnostics on the execution of their solver of choice. – Solve Script Output: (Design Assessment system only) Displays the log file from the python Solve script specified for the current Design Assessment system. – Evaluate Script Output: (Design Assessment system only) Displays the log file from the python Evaluate script specified for the current Design Assessment system. Choosing any of the following options displays a graph of that option as a function of Cumulative Iteration/Cycle (availability depends on the solver). – Force Convergence1 (p. 1044) – Displacement Convergence1 (p. 1044) – Rotation Convergence1 (p. 1044) – Moment Convergence1 (p. 1044) – Max DOF Increment – Line Search – Time – Time Increment – CSG Convergence1 (p. 1044) (magnetic current segments) – Heat Convergence1 (p. 1044) – Energy Conservation – shows plots of total energy, reference energy, work done, and energy error. – Momentum Summary – shows plots of X, Y and Z momentum and X, Y and Z impulse for the model. – Energy summary – shows plots of internal energy, kinetic energy, hourglass energy and contact energy.

Note The frequency at which data is written can be specified as a time step frequency or a physical time frequency. By default information is displayed for every 100 time steps.

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Understanding Solving 1 — All convergence plots include designations where any bisections, converged substeps, or converged steps occur. These designations are the red, green, and blue dotted lines shown in the example below of a Force Convergence plot.

Note For ease of viewing solutions with many substeps/iterations, the Substep Converged and Load Step Converged lines are not displayed when the number of lines exceeds 1000. Also, graphs are shown as lines only, rather than lines and points, when the number of points exceeds 1000.

• Newton-Raphson Residuals: [applicable only to Structural environments solved with the Mechanical APDL application] Specifies the maximum number of Newton-Raphson residual forces to return. The default is 0 (no residuals returned). You can request that the Newton-Raphson residual restoring forces be brought back for nonlinear solutions that either do not converge or that you aborted during the solution. The Newton-Raphson force is calculated at each Newton-Raphson iteration and can give you an idea where the model is not satisfying equilibrium. If you select 10 residual forces and the solution doesn’t converge, those last 10 residual forces will be brought back. The following information is available in the Details view of a returned Newton-Raphson Residual Force object: – Results — Minimum and Maximum residual forces across the model – Convergence — Global convergence Criterion and convergence Value – Information — Time based information These results cannot be scoped and will automatically be deleted if another solution is run that either succeeds or creates a new set of residual forces. • Update Interval: (appears only for synchronous solutions) Specifies how often any of the result tracking items under a Solution Information object get updated while a solution is in progress. The default is 2.5 seconds. • Display Points: [not applicable to Connections object] Specifies the number of points to plot for a graphical display determined by the Solution Output setting (described above). • Display Filter During Solve: [applicable only when using Result Tracker filtering in Explicit Dynamics analyses] When set to Yes, displays filtered data from Result Trackers in the Worksheet at each refresh

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Solution Information Object interval of the Result Tracker. As shown below, a legend is included in the Worksheet to help distinguish the filtered data from the non-filtered data. Typically there are two curves, non-filtered data is displayed in red, and filtered data is displayed in green.

Note If an error occurs during a solve when using the ANSYS solver, the Solution Information worksheet may point you to files (for example, file.err) in temporary scratch folders whose purpose is for solving only (this is the folder where ANSYS actually ran). After the solution, these files are moved back to the project structure, so you may not find them in the scratch folders (or sub-folders).

Viewing and Exporting Finite Element Connections During the solution, the Mechanical application will sometimes create additional elements or Constrain Equations (CE) for certain objects such as a remote boundary condition, spot weld, joint, MPC based contact, or weak spring. So that you might better understand how the boundary conditions are applied, the Mechanical application allows you to “view” these connections after a solution is completed. The following controls are available in the Details view under the FE Connection Visibility category: • Activate Visibility: Allows control on whether or not the finite element connection data is stored during the solution. If visualization of the finite element connections will never be desired or to maximize performance on extreme models in which many constraint equations exist, this feature can be deactivated by setting the value to No before solving the model. Note that in the case of a multiple step analysis, if constraint equations are present, they will be reported from the first load step. The default value for this property can be changed under Tools>Options>Analysis Settings. • Display: Allows control over which finite element connections are to be viewed. The options include: – All FE Connectors (Default)

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Understanding Solving

– CE Based (As illustrated below, outlined or hollow nodes indicate use for calculation purposes only.)

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Solution Information Object

– Beam Based – Weak Springs – None This control is especially useful to separate the constraint equation connections from the beam connections. The option None is available to assist in avoiding potential performance issues from this feature. • Draw Connections Attached To: provides a drop-down list with the option All Nodes (Default) and it will also list any existing node-based Named Selections. • Line Color: Assigns colors to allow you to differentiate connections. The options include: – Connection Type (Default): Displays a color legend that presents one color for constraint equation connections and another color for beam connections. – Manual: Displays a color that you choose. – Color: Appears if Line Color is set to Manual. By clicking in this field, you can choose a color from the color palette.

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Understanding Solving • Visible on Results: When set to Yes (Default), the finite element connections are displayed with any result plot (with the exception of a base mesh). When set to No, the connections are displayed only when the Solution Information object is selected. • Line Thickness: Displays the thickness of finite element connection lines in your choice of Single (default), Double, or Triple. • Display Type: allows you to view FE connections as Lines (Default) or as Points. If you wish to view the Points of a specified Named Selection, the nodes belonging to the Named Selection display as solid colors. Any other associated nodes not belonging to the Named Selection, display with an outline only. You can export the finite element connection information described above by right-clicking on the Solution Information object and choosing Export FE Connections from the context menu. The Display control governs what information is exported. Information for constraint equation connections is exported in terms of Mechanical APDL CE commands, while for beam and weak spring connections, a list of material numbers is exported and written as a block of Mechanical APDL ESEL commands.

Note Finite element connection information is not available for Response Spectrum analyses when the Spectrum Type property is set to Single Point.

Tracking Background Solutions When running background solutions, you can check the status of the solution by using the Retrieve feature, which is available in a context menu when you right-click the mouse button on the Solution Information object. A Retrieve button is also available on the Solution Information toolbar. In rare instances, the Retrieve feature could fail if the necessary files do not become available at a particular time. Simply choosing Retrieve again will likely solve the issue.

Postprocessing During Solve Postprocessing during a solve allows you to use postprocessing tools while an analysis is still in progress. This feature is useful for analyses that produce partial results (that is, analyses that produce intermediate results files that are readable but incomplete) such as all Static and Transient Structural, all Static and Transient Thermal, and Explicit Dynamics analyses. This feature is available only when you solve an analysis on a remote computer or as a background process. When you run the solution as a background process, you can add new results under the Solution object or use postprocessing features such as viewing results contours, animation, min and max labels, and so on. To postprocess results during a solve: 1. Set up the Remote Solve Manager (RSM) and run a solution. Request results for a specific time by entering the time in the Display Time field within the Details view of the Solution object. 2. Right-click on the Solution object and choose Evaluate All Results.

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Result Trackers If you chose a specific time point that is not yet solved, the result of the most recent solved point will be displayed in the output fields within the Details view.

Note When using this feature, it is important that you allow adequate time after the solve for the results files to be created and present before any postprocessing can be successful. Requesting a postprocessing function too prematurely could generate an error message stating that the result file could not be opened.

Result Trackers In addition to the real time solution response graphs you can view from the Solution Information object, you can also view graphs of specific displacement and contact results as a function of time using Result Tracker objects. These objects are inserted as branch objects under a Solution Information object. You cannot add new Result Trackers to completed solutions. In order to add and solve a new result, you must Clear the Solution, add a new Result Tracker, and then resolve the simulation.

Note Result Trackers employ the instructions of the MAPDL command, NLHIST.

Result Tracker Types The Result Tracker feature is available for the following: Structural Result Tracker Thermal Result Tracker Explicit Dynamics Result Tracker

Adding the Result Tracker Object To insert a Result Tracker object, select a Solution Information object in the tree and either choose an option under the Result Tracker drop-down menu in the Solution Information context toolbar, or perform a RMB click on the Result Tracker object, then insert a Result Tracker object.

Result Tracker Features The following options are offered by the Result Tracker object. Plotting Renaming Exporting

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Understanding Solving

Plotting a Result Tracker Any of the graphs created by either the Result Tracker or nonlinear convergence items have the following features: • Multiple Result Tracker objects may be selected at the same time to create a combined chart assuming they share the same X and Y output types (such as pressure for Y and time for X). An example is shown here:

• The graph can be zoomed by using the ALT key + left mouse button. Moving down and to the right zooms in, and moving up and to the left zooms out. • A plot can be saved by using the Image Capture toolbar button.

Caution Because nodes may be rotated in solutions obtained with the Mechanical APDL application, deformation Result Trackers may not record the expected component of the deformation. Should this occur, a warning message alerting you to this will appear after the solve in the Details view of the Solution object, in the Solver Messages field. This situation can occur when Result Trackers are adjacent to supported faces, lines, or vertices. One possible approach to avoid this situation is to add 3 deformation Result Trackers, one for each of the x, y, and z directions. This will ensure that the tracker is showing all deformation of that vertex of the model.

Renaming a Result Tracker The Result Tracker has an option for renaming the object based on the result and the scoping. You choose the option in the context menu (RMB click). This option is useful in having the program create meaningful names of the result trackers. An example would be Result Tracker 5 being renamed to Pressure on Contact Region 2.

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Result Trackers

Exporting a Result Tracker Result Tracker objects can be exported to an Excel file by selecting Export in the context menu using a right-mouse button click on the Result Tracker object. This option appears in the menu after the solution is obtained.

Note You must right-mouse click on the selected object in the tree to use this Export feature. On Windows platforms, if you have the Microsoft Office 2002 (or later) installed, you may see an Export to Excel option if you right-mouse click in the Worksheet window. This is not the Mechanical application Export feature but rather an option generated by Microsoft Internet Explorer.

Structural Result Trackers A Structural Analysis supports the following Result Trackers. • Deformation (p. 1051) • Contact (p. 1052) • Kinetic Energy and Stiffness Energy (p. 1053) The Details view categories and options for each are described below.

Note Direct graphical node selection requires you to generate the mesh and have the Show Mesh tool chosen. Deformation: displacement for one vertex only using the geometry picker or a geometry-based Named Selection or a node-based Named Selection for a single node. • Scope – Scoping Method: options include Geometry Selection or Named Selection. – Geometry: visible when Geometry Selection is specified as the Scoping Method. This field allows you to select and define a single vertex or a single node as the geometry. – Named Selection: visible when Named Selection is specified as the Scoping Method. This field provides a list of user-defined Named Selections that are either geometry-based or node-based. • Definition – Type: Read-only field that displays the type of Results Tracker. – Orientation: Specifies X-Axis, Y-Axis, or Z-Axis. – Suppressed: Prior to solving, you can include or exclude the result from the analysis. The default is value is No.

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Understanding Solving • Results – Minimum: Read-only indication of the minimum value of the result tracker type. – Maximum: Read-only indication of the maximum value of the result tracker type. Contact: for contact outputs scoped to a given contact pair. • Definition – Type: Specifies the particular contact output. For each of these options, the result tracking is performed on the Contact side of the pair. If you want to perform the result tracking on the Target side, you should flip the source and target sides. If this occurs you can change the contact region to Asymmetric and flip the source and target faces in order to specify the side of interest that is to be the contact side. If Auto Asymmetric contact is active (either by the Behavior contact region setting equaling Auto Asymmetric or by the Formulation setting equaling Augmented Lagrange (p. 516) or MPC (p. 516)) and the contact side is chosen by the program to be disabled, the Results Tracker will not contain any results (as signified by a value of -2 for Number Contacting output). Contact results will be valid depending on the type of contact (for example, edge-edge) and the contact formulation. → Pressure: Maximum pressure. → Penetration: Maximum penetration. → Gap: Minimum gap. The values will be reported as negative numbers to signify a gap. A value of zero is reported if the contact region is in contact (and thus has a penetration). Also, if the region is in far-field contact (contact faces are outside the pinball radius), then the gap will be equal to the resulting pinball size for the region. → Frictional Stress: Maximum frictional stress. → Sliding Distance: Amplitude of total accumulated sliding when the contact status is sticking or sliding. → Number Sticking: Number of elements that are sticking. → Number Contacting (default): Number of elements in contact. A value of -1 means the contact pair is in far field contact (meaning the faces lie outside the contact pinball region). → Chattering: Maximum chattering level. → Elastic Slip: Maximum elastic slip. → Normal Stiffness: Maximum normal stiffness. → Max Tangential Stiffness: Maximum tangential stiffness. → Min Tangential Stiffness: Minimum tangential stiffness. → Contacting Area: The total area of the elements that are in contact. → Max Damping Pressure: Maximum damping pressure. → Fluid Pressure: Maximum fluid penetration pressure.

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Result Trackers → Min Geometric Sliding Distance: Minimum total sliding distance, including sticking, sliding, and near-field. For more information, see the GSLID output parameter in the Mechanical APDL Contact Technology Guide. → Max Geometric Sliding Distance: Maximum total sliding distance, including sticking, sliding, and near-field. For more information, see the GSLID output parameter in the Mechanical APDL Contact Technology Guide. – Suppressed: Prior to solving, you can include or exclude the result from the analysis. The default is value is No. • Scope – Contact Region: Specifies the particular contact region in the pair. Default names are Contact Region and Contact Region 2. • Results – Minimum: Read-only indication of the minimum value of the result tracker type. – Maximum: Read-only indication of the maximum value of the result tracker type. Kinetic Energy and Stiffness Energy • Definition – Type: Read-only field that displays the type of Results Tracker. – Suppressed: Prior to solving, you can include or exclude the result from the analysis. The default is value is No. • Results – Minimum: Read-only indication of the minimum value of the result tracker type. – Maximum: Read-only indication of the maximum value of the result tracker type.

Thermal Result Trackers A Thermal Analysis supports the Temperature Result Tracker only. The Temperature can be applied to one vertex only using the geometry selection tools or using a geometry-based Named Selection or for a single node, node-based Named Selection.

Note Direct graphical node selection requires you to generate the mesh and have the Select Mesh tool chosen. The Details view properties and options for the Temperature Result Tracker are described below. • Definition – Type: Read-only field that displays the type of Results Tracker.

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Understanding Solving – Suppressed: Prior to solving, you can include or exclude the result from the analysis. The default is value is No. • Scope: – Scoping Method: Specifies the option Geometry Selection, Named Selection, Global Minimum, or Global Maximum for a solution point. – Geometry: visible when Geometry Selection is specified as the Scoping Method. This field allows you to select and define a single vertex as the geometry or a single node. – Named Selection: visible when Named Selection is specified as the Scoping Method. This field provides a list of user-defined Named Selections that are either geometry-based or node-based. – Global Minimum: – Global Maximum: • Results – Minimum: Read-only indication of the minimum value of the result tracker type. – Maximum: Read-only indication of the maximum value of the result tracker type.

Explicit Dynamics Result Trackers The following topics are related specifically to result trackers in explicit dynamics analyses: Point Scoped Result Trackers for Explicit Dynamics Body Scoped Result Trackers for Explicit Dynamics Force Reaction Result Trackers for Explicit Dynamics Spring Result Trackers for Explicit Dynamics Viewing and Filtering Result Tracker Graphs for Explicit Dynamics

Point Scoped Result Trackers for Explicit Dynamics A point scoped result tracker is used to create a Gauge point in the ANSYS AUTODYN solver. These are either associated with a node or element center, depending on the variable selected. If the location specified in the Mechanical application interface does not correspond to a node or element center then the nearest node or element is used.

Note The point scoped trackers are only available for an explicit dynamics analysis. Point scoped trackers may only be inserted prior to the analysis being solved. You can specify the location of point scoped Explicit Dynamics result trackers in three ways: • Selecting a vertex on the geometry. 1. Set Location Method to Geometry Selection. 2. Select a vertex, click in the Geometry field, then click Apply. • Selecting a point using the Coordinate toolbar button. 1054

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Result Trackers 1. Set Location Method to User Defined Location. 2. Choose Click to Change in the Location field. 3. Depress the Coordinate toolbar button. 4. Move the cursor across the model and notice that the coordinates display and update as you reposition the cursor. 5. Click at the desired location. A small cross hair appears at this location. You can click again at another location, which changes the cross hair location. 6. Click Apply in the Location field. The location coordinates display in the X, Y, Z Coordinate fields. You can change the location by repositioning the cursor, clicking at the new location, then clicking Click to Change and Apply, or by editing the X, Y, Z Coordinate fields in the Details view. • Selecting a point by entering coordinates directly in the Details view. 1. Set Location Method to User Defined Location. 2. Type the coordinates in the X, Y, Z Coordinate fields in the Details view. Point scoped result trackers for explicit dynamics analyses are presented in the main bulleted items below. The Details view settings for each are presented as sub-bulleted items. Included in the Details view of all Explicit Dynamics result trackers is a low-pass filter option, not listed below. • Deformation – Location Method – Select geometry or a user defined location. – Coordinate System – Assigned to user defined location. – X, Y, Z Coordinate – Position of the user defined location. – Location – Select user defined location. – Type – Select deformation type. – Orientation – Deformation along X, Y, or Z axis. – Geometry – Select vertex. – Suppressed – Prior to solving, you can include or exclude the result from the analysis. The default is value is No. • Position – Type – Read only. – Location Method – Select geometry or a user defined location. – Coordinate System – Assigned to user defined location. – X, Y, Z Coordinate – Position of the user defined location.

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Understanding Solving – Location – Select user defined location. – Orientation – Position along X, Y, or Z axis. – Geometry – Select vertex. – Suppressed – Prior to solving, you can include or exclude the result from the analysis. The default is value is No. • Velocity – Location Method – Select geometry or a user defined location. – Coordinate System – Assigned to user defined location. – X, Y, Z Coordinate – Position of the user defined location. – Location – Select user defined location. – Type – Select velocity type. – Orientation – Velocity along X, Y, or Z axis. – Geometry – Select vertex. – Suppressed – Prior to solving, you can include or exclude the result from the analysis. The default is value is No. • Acceleration – Location Method – Select geometry or a user defined location. – Coordinate System – Assigned to user defined location. – X, Y, Z Coordinate – Position of the user defined location. – Location – Select user defined location. – Type – Select acceleration type. – Orientation – Acceleration along X, Y, or Z axis. – Geometry – Select vertex. – Suppressed – Prior to solving, you can include or exclude the result from the analysis. The default is value is No. • Internal Energy – Type – Read only. – Location Method – Select geometry or a user defined location. – Coordinate System – Assigned to user defined location. – X, Y, Z Coordinate – Position of the user defined location.

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Result Trackers – Location – Select user defined location. – Geometry – Select vertex. – Suppressed – Prior to solving, you can include or exclude the result from the analysis. The default is value is No. • Stress – Location Method – Select geometry or a user defined location. – Coordinate System – Assigned to user defined location. – X, Y, Z Coordinate – Position of the user defined location. – Location – Select user defined location. – Type – Select stress type. – Geometry – Select vertex. – Suppressed – Prior to solving, you can include or exclude the result from the analysis. The default is value is No. • Strain (Scoping: not available for Euler bodies) – Location Method – Select geometry or a user defined location. – Coordinate System – Assigned to user defined location. – X, Y, Z Coordinate – Position of the user defined location. – Location – Select user defined location. – Type – Select strain type. – Geometry – Select vertex. – Suppressed – Prior to solving, you can include or exclude the result from the analysis. The default is value is No. • Temperature – Type – Read only. – Location Method – Select geometry or a user defined location. – Coordinate System – Assigned to user defined location. – X, Y, Z Coordinate – Position of the user defined location. – Location – Select user defined location. – Type – Read only. – Geometry – Select vertex.

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Understanding Solving – Suppressed – Prior to solving, you can include or exclude the result from the analysis. The default is value is No. • Pressure – Type – Read only. – Location Method – Select geometry or a user defined location. – Coordinate System – Assigned to user defined location. – X, Y, Z Coordinate – Position of the user defined location. – Location – Select user defined location. – Geometry – Select vertex. – Suppressed – Prior to solving, you can include or exclude the result from the analysis. The default is value is No. • Density – Type – Read only. – Location Method – Select geometry or a user defined location. – Coordinate System – Assigned to user defined location. – X, Y, Z Coordinate – Position of the user defined location. – Location – Select user defined location. – Geometry – Select vertex. – Suppressed – Prior to solving, you can include or exclude the result from the analysis. The default is value is No.

Note Density is not calculated for shell and beam elements.

Importing Point Scoped Result Trackers From a File Choosing Result Trackers From File from the Result Tracker drop down menu in the toolbar enables you to import point scoped result trackers from a file. The format of the file should be as in the following example: cm 1;2;3;velx;velocity;x 1.4;2.5;3.745;My Deformation;Deformation;Total 10;20;30;prin max strain;strain;principal1 10;20;30;middle strain;strain;principal2

The first line, «cm» represents the units of the values in the file. Acceptable inputs for this are: «m», «cm», «mm», «in», «ft», or «um».

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Result Trackers The subsequent lines contain the data for each tracker to be inserted. The first three numbers are the x,y,z location values. The fourth entry is the user given name — the one that will be seen in the tree. The 5th and 6th entries are type and subtype. Acceptable entries for type and subtype are: type = «velocity», «acceleration» or «deformation» with subtypes of «x»,»y»,»z» or «total» type = «position», «temperature», «pressure», «energy» or «density» (no subtype used) type = «stress» or «strain» with subtypes of «xx», «yy», «zz», «xy», «yz», «zx», «principal1», «principal2», «principal3», «equivalent» All values in each line should be separated by a semicolon. Any lines that are not properly formatted will be skipped — no tracker will be inserted for them.

Body Scoped Result Trackers for Explicit Dynamics Body scoped result trackers for explicit dynamics analyses are presented in the main bulleted items below. The Details view settings for each are presented as sub-bulleted items. • Momentum (Scoping: flexible or rigid bodies) – Definition → Type – Read only. → Orientation – Select X, Y, or Z axis. → Suppressed – Prior to solving, you can include or exclude the result from the analysis. The default is value is No. – Scope → Geometry – Select bodies. – Results → Minimum – Read-only indication of the minimum value of the result. tracker type. → Maximum – Read-only indication of the maximum value of the result. tracker type. – Filter → Type – Specify low-pass filtering option. • Total Mass Average Velocity (Scoping: flexible or rigid bodies) – Definition → Type – Read only. → Orientation – Select X, Y, or Z axis.

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Understanding Solving → Suppressed – Prior to solving, you can include or exclude the result from the analysis. The default is value is No. – Scope → Geometry – Select bodies. – Results → Minimum – Read-only indication of the minimum value of the result. tracker type. → Maximum – Read-only indication of the maximum value of the result. tracker type. – Filter → Type – Specify low-pass filtering option. • Contact Force (Scoping: flexible or rigid bodies; not available for Euler bodies) – Definition → Type – Read only. → Orientation – Select X, Y, or Z axis. → Suppressed – Prior to solving, you can include or exclude the result from the analysis. The default is value is No. – Scope → Geometry – Select bodies. – Results → Minimum – Read-only indication of the minimum value of the result. tracker type. → Maximum – Read-only indication of the maximum value of the result. tracker type. – Filter → Type – Specify low-pass filtering option. • External Force (Scoping: flexible or rigid bodies; not available for Euler bodies) – Definition → Type – Read only. → Orientation – Select X, Y, or Z axis. → Suppressed – Prior to solving, you can include or exclude the result from the analysis. The default is value is No. – Scope

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Result Trackers → Geometry – Select bodies. – Results → Minimum – Read-only indication of the minimum value of the result. tracker type. → Maximum – Read-only indication of the maximum value of the result. tracker type. – Filter → Type – Specify low-pass filtering option. • Kinetic Energy (Scoping: flexible or rigid bodies) – Definition → Type – Read only. → Suppressed – Prior to solving, you can include or exclude the result from the analysis. The default is value is No. – Scope → Geometry – Select bodies. – Results → Minimum – Read-only indication of the minimum value of the result. tracker type. → Maximum – Read-only indication of the maximum value of the result. tracker type. – Filter → Type – Specify low-pass filtering option. • Total Energy (Scoping: flexible or rigid bodies) – Definition → Type – Read only. → Suppressed – Prior to solving, you can include or exclude the result from the analysis. The default is value is No. – Scope → Geometry – Select bodies. – Results → Minimum – Read-only indication of the minimum value of the result. tracker type. → Maximum – Read-only indication of the maximum value of the result. tracker type. – Filter Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Understanding Solving → Type – Specify low-pass filtering option. • Internal Energy (Scoping: flexible bodies only) – Definition → Type – Read only. → Location Method – Select geometry or a user defined location. → Coordinate System – Assigned to user defined location. → X, Y, Z Coordinate – Position of the user defined location. → Location – Select user defined location. → Suppressed – Prior to solving, you can include or exclude the result from the analysis. The default is value is No. – Scope → Geometry – Select bodies for Location Method of Geometry Selection. – Results → Minimum – Read-only indication of the minimum value of the result. tracker type. → Maximum – Read-only indication of the maximum value of the result. tracker type. – Filter → Type – Specify low-pass filtering option. • Plastic Work (Scoping: flexible bodies only) – Definition → Type – Read only. → Suppressed – Prior to solving, you can include or exclude the result from the analysis. The default is value is No. – Scope → Geometry – Select bodies. – Results → Minimum – Read-only indication of the minimum value of the result. tracker type. → Maximum – Read-only indication of the maximum value of the result. tracker type. – Filter → Type – Specify low-pass filtering option.

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Result Trackers

Force Reaction Result Trackers for Explicit Dynamics Result trackers that can be scoped to boundary conditions and geometry are available for explicit dynamics analyses. The Details view settings are presented as sub-bulleted items under the tracker bullet. • Force Reaction tracker – Location Method – Select the scoping method for this tracker. Options are Boundary Condition and Geometry Selection. – Boundary Condition – When Boundary Condition is selected as the Location Method, select the defined boundary condition that is to be used for scoping. At this time, the boundary conditions that are available are: Velocity and Displacement. – Geometry – When Geometry Selection is selected as the Location Method, select the vertex, edge, face, or body where the tracker will be located. – Force Component – When Geometry Selection is selected as the Location Method, select the Force Component (Support, Euler/Lagrange Coupling, Contact, All) for which reaction force results will be shown. Euler/Lagrange Coupling specifies that the tracker show results for the forces exerted by any material in bodies assigned with an Eulerian reference frame that interact with the scoped region. These trackers can only be scoped to geometry that has a Lagrangian reference frame. See Explicit Fluid Structure Interaction (Euler-Lagrange Coupling) (p. 1786) for more information about Euler Lagrange interactions. Support specifies that the tracker show results for the forces that will be generated due to supports that are acting on the scoped area. Contact specifies that the tracker show results for the total force resulting from the contact forces acting on the scoped area. All specifies that the tracker show results for the sum of all three components. – Orientation – Select X, Y, or Z axis, or Total, which is the resultant force of its X, Y, and Z components. • The Filter option in the Details view is defined in the same manner as any other result tracker (see Viewing and Filtering Result Tracker Graphs for Explicit Dynamics (p. 1064)). The reaction force will be shown varying over time in the Graph window, and a table is displayed that shows the data. The magnitude of the reaction force is calculated by summing the reaction forces on each of the nodes selected by the scoping. For example, if you have scoped the tracker by Geometry Selection to a face using the Contact Force Component, the magnitude of the reaction force is the sum of all reaction forces due to contact at the nodes on the selected face. If you scope by Boundary Condition, the magnitude will be the sum of all of the reaction forces due to Support on the nodes scoped to the selected boundary condition.

Note • The Force Reaction trackers are only available for an explicit dynamics analysis.

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Understanding Solving • If you right click on a Force Reaction tracker and select Rename Based on Definition, the tracker is renamed based on its type, the direction it shows results for, and the object it is scoped to. For example, if a Force Reaction tracker is selected to show results in the Y direction and is scoped to a Velocity constraint boundary condition named «Velocity Fix», by selecting Name Based on Definition it will be renamed to «Y Force Reaction at Velocity Fix». See Renaming a Result Tracker (p. 1050) for more information on this renaming behavior.

Spring Result Trackers for Explicit Dynamics You can use a spring tracker to display the following longitudinal result items from a spring in an Explicit Dynamics analysis: • Elongation – Elongation is the relative displacement between the two ends of the springs. The elongation could be positive (stretching the spring) or negative (compressing the spring). • Velocity – Velocity is the rate of stretch (or compression) of the spring. • Elastic Force – Elastic force is calculated as (Spring Stiffness * Elongation). The force acts along the length of the spring. • Damping Force – Damping force is calculated as (Damping Factor * velocity) and acts to resist motion.

Viewing and Filtering Result Tracker Graphs for Explicit Dynamics Explicit dynamics analyses typically involve a large number of time history samples, sometimes in the order of hundreds of thousands, and the results tend to include high frequency noise that can obscure slow rate phenomena. A low-pass filtering option is available that allows you to separate slow-rate trends from high frequency noise in signals. This feature can be controlled from the Details view of a Result Tracker object. The filtered results are displayed by default in the Timeline window after the solve. By setting Display Filter During Solve to Yes in the Details view of the Solution Information object, the filtered results can also be displayed in the Worksheet at each refresh interval of the Result Tracker. To configure the low-pass filter for the sampled data: • Under Filter, set the following controls: – Type: Set to one of the following: → None: (Default) No filtering is applied to the data. → Butterworth: Applies a four-channel low-pass Butterworth filter to the data. Two channels are passed twice, once in the forward direction and once in the reverse direction, to prevent phase shifts. – Cut Frequency (displayed if Type is set to Butterworth): Set to the desired cut frequency in Hz or MHz depending on the current unit system. The default is 0, which implies no filtering. Notes A time history data is composed of a limited number of frequency signals that bound the range of meaningful cut frequencies to use for filtering. If the cut frequency is too low, most signals will be lost. On the other hand, if the cut frequency is too high, the signal may remain unaltered. 1064

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Adaptive Convergence In determining a good cut frequency, sampling frequency plays a role. The sampling frequency can be obtained by dividing the number of samples by the sampling duration. The cut frequency should not exceed a quarter of this value. For example, if 15,000 samples occur in 0.015 seconds, the sampling frequency will be 15,000/(0.015 s) = 1,000,000 Hz = 1 MHz. Consequently, the cut frequency should not exceed 0.25 MHz. The process of filtering pads the original signal with extrapolated data. This may produce unexpected shapes in the filtered signal near the margins. The data away from the margins should reflect, however, the proper trends and slow rate phenomena. The signal is not filtered at all if it has less than 11 samples. Under Filter, if Type is set to Butterworth, there are also read only indications for the Minimum and Maximum values of the filtered data.

Adaptive Convergence You can control the relative accuracy of a solution in two ways. You can use the meshing tools to refine the mesh before solving, or you can use convergence tools as part of the solution process to refine solution results on a particular area of the model. This section discusses the latter. Through its convergence capabilities, the application can fully automate the solution process, internally controlling the level of accuracy for selected results. You can seek approximate results or adapted/converged results. This section explains how to interpret accuracy controls.

Converged Results Control You can control convergence to a predefined level of error for selected results. In the calculation of stresses, displacements, mode shapes, temperatures, and heat fluxes, the application employs an adaptive solver engine to identify and refine the model in areas that benefit from adaptive refinement. The criteria for convergence is a prescribed percent change in results. The default is 20%. You can change this default using the Convergence setting in the Options dialog box.

Adaptivity (Refinement of meshes based on solutions) You can continue to refine the mesh based on a specific solution result. When you pick a result (Equivalent Stress, Deformation, Total Flux Density, etc.), indicate that you want to converge on this solution. You pick a value and the solution is refined such that the solution value does not change by more than that value. To add convergence, click the result you added to your solution; for example, Equivalent Stress , Total Deformation, or Total Flux Density. If you want to converge on deformation, right-click on Total Deformation and select Insert> Convergence. In the Details View (p. 11), you can specify convergence

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Understanding Solving on either the Minimum or Maximum value. Additionally, you can specify the Allowable Change between convergence iterations.

Note • Convergence objects inserted under an environment that is referenced by an Initial Condition object or a Thermal Condition load object, will invalidate either of these objects, and not allow a solution to progress. • Results cannot be converged when you have a Mesh Connection object or a Pinch control with Pinch Behavior set to Post. • To use Convergence, you must set Calculate Stress to Yes under Output Controls in the Analysis Settings details panel. However, you can perform Modal and Buckling Analysis without specifying this option. • You cannot use Convergence if you have an upstream or a downstream analysis link. • Convergence is not available when you import loads into the analysis. • Convergence is not supported for a model with Layered Sections. • Convergence is not supported for Design Assessment. • Convergence is not supported for Solution Combinations.

For an adaptive solution, a solution is first performed on the base mesh, and then the elements are queried for their solution information (such as deflection, X-stress, Y-stress, etc.). If the element’s results have a high Zienkiewicz-Zhu, or ZZ error (see the Mechanical APDL Theory Reference for more information on adaptivity theory), the element is placed in the queue to be refined. The application then continues to refine the mesh and perform additional solutions. Adaptivity will be more robust if your initial mesh is with tetrahedrons. Adaptive refinement starting from a hex-dominant mesh will automatically result in a re-meshing of the structure with tetrahedrons. The face mesh given to the tet mesher is the initial quad mesh split into triangles. That face mesh is then filled with tetrahedrons so it is recommended that you insert an all tetrahedron mesh method before you start an adaptive solution. You can control the aggressiveness of the adaptive refinement by adjusting the Refinement Depth setting under Adaptive Mesh Refinement in the Details view of a Solution object. The default value is 2 for structural analyses, and 0 for magnetostatic analyses. The range is from 0 to 3. By default, when adaptive convergence occurs, the program will refine to a depth of 2 elements to help ensure smooth transitions and avoid excessive element distortion for repeated refinement. However, you can adjust this refinement depth to a value of 0 or 1 if for a particular problem, the deep refinement is not required and problem size is a major concern. In general, for mechanical analyses, the default value of 2 is highly recommended. However, you can lower the value if too much refinement is occurring and is overwhelming the solution in terms of size of solution time. If you use a value less than 2, be aware of the following: • Verify that false convergence is not occurring because of too little refinement. • More refinements may be required to achieve the desired tolerance, which may increase the total solution time. The following pictures show the effects of various settings of Refinement Depth on plots of Total Deformation. 1066

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Adaptive Convergence

Base Mesh: No Refinement

Refinement Depth = 1

Refinement Depth = 0

Refinement Depth = 2

For magnetostatic analyses, there are additional settings that allow you to change the percentage of the element selected for adaptive refinement during solution. These settings use an Energy Based percentage and an Error Based percentage. The internal selection process first uses the Energy Based percentage to select the number of elements in the full model that have the highest values of magnetic energy. From this number, it uses the Error Based percentage to select the number of elements with the highest error in the particular body. Magnetic Error results are also available to display on the geometry for verification. These adaptive refinement settings for magnetostatic analyses are in the Refinement Controls group, located in the Details view of the Solution object, provided you have a Convergence object inserted under any magnetostatic result. An Element Selection setting in this group has the following options: • Program Controlled (default): The percentage of elements selected for adaptive refinement equals the default values of 10% for the Energy Based percentage and 20% for the Error Based percentage. • Manual: The percentage of elements selected for adaptive refinement equals the values you enter in the Energy Based and Error Based fields that appear only when you choose Manual.

Adaptive Convergence in Multiple Result Sets You can apply adaptive convergence on multiple result sets that may include different loadings or time points. To do so, create a result for each loading or time point and insert a Convergence object under each result. The following example shows Total Deformation results at two time points where a Convergence object was inserted under each result.

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Understanding Solving

ANSYS Workbench Product Adaptive Solutions Nearly every ANSYS Workbench product result can be calculated to a user-specified accuracy. The specified accuracy is achieved by means of adaptive and iterative analysis, whereby h-adaptive methodology is employed. The h-adaptive method begins with an initial finite element model that is refined over various iterations by replacing coarse elements with finer elements in selected regions of the model. This is effectively a selective remeshing procedure. The criterion for which elements are selected for adaptive refinement depends on geometry and on what ANSYS Workbench product results quantities are requested. The result quantity φ, the expected accuracy E (expressed as a percentage), and the region R on the geometry that is being subjected to adaptive analysis may be selected. The user-specified accuracy is achieved when convergence is satisfied as follows:

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Adaptive Convergence where i denotes the iteration number. It should be clear that results are compared from iteration i to iteration i+1. Iteration in this context includes a full analysis in which h-adaptive meshing and solving are performed. The ANSYS Workbench product uses two different criteria for its adaptive procedures. The first criterion merely identifies the largest elements (LE), which are deleted and replaced with a finer finite element representation. The second employs a Zienkiewicz-Zhu (ZZ) norm for stress in structural analysis and heat flux in thermal analysis. Table 4: ANSYS Workbench Product Adaptivity Methods Result

Adaptive Criterion

Stresses and strains

ZZ norm

Structural margins and factors of safety

ZZ norm

Fatigue damage and life

ZZ norm

Heat flows

ZZ norm

Temperatures

ZZ norm

Deformations

ZZ norm

Mode frequencies

LE

As mentioned above, geometry plays a role in the ANSYS Workbench product adaptive method. In general, accurate results and solutions can be devised for the entire assembly, a part or a collection of parts, or a surface or a collection of surfaces. The user makes the decision as to which region of the geometry applies. If accurate results on a certain surface are desired, the ANSYS Workbench product ignores the aforementioned criterion and simply refines all elements on the surfaces that comprise the defined region. The reasoning here is that the user restricts the region where accurate results are desired. In addition, there is nothing limiting the user from having multiple accuracy specification. In other words, specified accuracy in a selected region and results with specified accuracy over the entire model can be achieved.

General Notes Adaptive convergence is not supported for orthotropic materials. Adaptive convergence is not supported for solid shell elements (the SOLSH190 series elements). Adaptive convergence is not valid for linked environments where the result of one analysis is used as input to another analysis. See the Define Initial Conditions (p. 136) section for details. Low levels of accuracy are acceptable for demonstrations, training, and test runs. Allow for a significant level of uncertainty in interpreting answers. Very low accuracy is never recommended for use in the final validation of any critical design. Moderate levels of accuracy are acceptable for many noncritical design applications. Moderate levels of accuracy should not be used in a final validation of any critical part. High levels of accuracy are appropriate for solutions contributing to critical design decisions. When convergence is not sought, studies of problems with known answers yield the following behaviors and approximated errors:

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Understanding Solving At maximum accuracy, less than 20% error for peak stresses and strains, and minimum margins and factors of safety. At maximum accuracy, between 5% and 10% error for average (nominal) stresses and elastic strains, and average heat flows. At maximum accuracy, between 1% and 5% error for average stress-related displacements and average calculated temperatures. At maximum accuracy, 5% or less error for mode frequencies for a wide range of parts. When seeking highly accurate, Converged Results, more computer time and resources will be required than Manual control, except in some cases where the manual preference approaches highest accuracy. Given the flexible nature of the solver engine, it is impossible to explicitly quantify the effect of a particular accuracy selection on the calculation of results for an arbitrary problem. Accuracy is related only to the representation of geometry. Increasing the accuracy preference will not make the material definition or environmental conditions more accurate. However, specified converged results are nearly as accurate as the percentage criteria. Critical components should always be analyzed by an experienced engineer or analyst prior to final acceptance. For magnetostatic analyses, Directional Force results allow seeking convergence based on Force Summation or Torque as opposed to other results converging on Maximum or Minimum values. Adaptive convergence is not valid if a Periodic Region or Cyclic Region symmetry object exists in the model. Adaptive convergence is not valid if an imported load object exists in the environment.

File Management in the Mechanical Application During the solution, several files are created. Some of these can be deleted after the solution but some need to be retained for postprocessing or for feeding other subsequent analyses. Since you can perform several different analyses on a single model or even have several models in the same Mechanical application project, you must manage the solution files in a consistent and predictable manner.

Consistent Directory Structure for Mechanical Application Analyses ANSYS Workbench’s file management system keeps multiple databases under a single project. See Project File Management for a description of the file management system.

Note The Analysis Settings Details view has an Analysis Data Management grouping that shows the solution directory location for each analysis.

Solution Files Default behavior: By default an analysis in the Mechanical application saves only the minimal files required for postprocessing. Typically these include results files (file.rst, file.rth, file.rmg, file.psd, file.mcom), input file (ds.dat), output file (solve.out), and some other files that

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Solving Units have valuable information about the solution ( file.BCS, file.nlh, file.gst). Of these only the results file is generally of significant size. For Windows users, the solution files folder can be displayed using the Open Solver Files Directory feature. Future Analysis: If the results of this analysis are to be used as a load or an initial condition in a subsequent analysis then additional files may need to be saved. Declaring your intent to use this in the future will automatically save the required files and reuse them in the subsequent analysis. Refer to Define Initial Conditions (p. 136) for details of these analyses. Delete Unneeded Files: The solution process creates other files that are typically not needed for postprocessing or are not used in subsequent analyses. By default, the Mechanical application deletes these files at the end of solution. However, if for any reason, you want to keep all the files you could choose to do so. You can use the Output Controls on the analysis settings page to limit only desired types of results be written to the rst file. (For example, if strains are not needed, you can turn them off which would create a smaller result file). In addition, for advanced Mechanical APDL application users, Command objects can be used to further limit output via the OUTRES command. An external result file is needed to post results. The following behavior will occur: • If you save a simulation, any simulation files (result and other required files) will be saved to the new location. • If you use the Duplicate Without Results option (Environment and Model objects only), all subordinate objects are reproduced with the exception of the data for all result objects. This is based on the intention that loading changes are performed and the solution process is repeated. • If you attempt to resolve a previously solved and saved database, the corresponding saved result files are backed up automatically in case the current solve is not saved. • The /post1 XML transfer of result files used in previous releases is no longer used so any existing solution Command objects which were modifying the Mechanical APDL application results to be brought back into the Mechanical application no longer function.

Solving Units There are eight possible unit systems for a Mechanical application solution. The following tables show the unit systems for the various quantities. For a given Mechanical application run, one of the eight systems is selected and all quantities are converted into that system. This guarantees that all quantities, inputs and outputs to the Mechanical APDL application, can be interpreted correctly in terms of the units in the system. User units shown anywhere in the GUI may differ from those shown below although they will convert properly when they are sent to the solver. All magnetostatic analyses solve in the mks system regardless of the system selected.

Note All «ton» designations in the table indicate metric ton. Acceleration

Angle

Angular Acceleration

Angular Velocity

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Area

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Understanding Solving Capacitance Current Density

Charge Decay Constant

Charge Density Density

Conductivity Displacement

Electric Conductivity Energy Density by Mass Force Per Angular Unit

Electric Field

Electric Flux Density Film Coefficient

Electric Resistivity Force

Force Intensity

Frequency

Gasket Stiffness

Heat Flux

Heat Generation

Energy Per Volume Fracture Energy (Energy Release Rate) Heat Rate

Impulse

Inductance

Inverse Angle

Inverse Length

Inverse Stress

Impulse Per Angular Unit Length

Magnetic Flux

Magnetic Flux Density Moment of Inertia of Mass Power

Mass Normalized Value Pressure

PSD Acceleration

PSD Displacement PSD Stress

PSD Force

PSD Moment

PSD Pressure

PSD Acceleration (G) PSD Strain

PSD Velocity

Rotational Stiffness RS Velocity

RS Acceleration

Relative Permeability RS Displacement

Relative Permittivity RS Strain

Rotational Damping RS Stress

Section Modulus

Shear Elastic Strain Stiffness

Shock Velocity

Thermal Capacitance

Moment of Inertia of Area Poisson’s Ratio

Seebeck Coefficient Specific Weight

Specific Heat

Square Root of Length Strength

Material Impedance Permeability

Magnetic Field Intensity Moment Permittivity

Strain

Stress

Stress Intensity Factor

Thermal Conductance — 3D Edge and Vertex Time

Thermal Expansion

Temperature

Temperature Difference

Thermal Conductance — 3D Face and 2D Edge Temperature Gradient

Translational Damping

Velocity

Voltage

Volume

Table 5: Acceleration and RS Acceleration Unit System

Measured in . . .

o

meters/second2 [m/s2]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

centimeters/second2 [cm/s2]

(cgs) mm, kg, N, oC, s, mV, mA

millimeters/second2 [mm/s2]

(nmm)

1072

Current Electric Conductance Per Unit Area Energy

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Solving Units Unit System

Measured in . . .

o

mm, t, N, C, s, mV, mA

millimeters/second2 [mm/s2]

(nmmton) mm, dat, N, oC, s, mV, mA

millimeters/second2 [mm/s2]

(nmmdat) µm, kg, µN, oC, s, V, mA

micrometers/second2 [µm/s2]

(µmks) ft, lbm, lbf, oF, s, V, A

feet/second2 [ft/s2]

(Bft) in, lbm, lbf, oF, s, V, A

inches/second2 [in/s2]

(Bin) millimeters/millisecond2 [mm/ms2]

mm, mg, ms [ANSYS (AUTODYN) and LS-DYNA solvers]

meters/second2 [m/s2]

m, kg, s [ LS-DYNA solver]

millimeters/second2 [mm/s2]

mm, t, s [ LS-DYNA solver]

inches/second2 [in/s2]

in,lbf, s [ LS-DYNA solver] Table 6: Angle Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

radians [rad]

(mks) cm, g, dyne, oC, s, V, A

radians [rad]

(cgs) mm, kg, N, oC, s, mV, mA

radians [rad]

(nmm) mm, t, N, oC, s, mV, mA

radians [rad]

(nmmton) mm, dat, N, oC, s, mV, mA

radians [rad]

(nmmdat) µm, kg, µN, oC, s, V, mA

radians [rad]

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Understanding Solving Unit System

Measured in . . .

(µmks) ft, lbm, lbf, oF, s, V, A

radians [rad]

(Bft) in, lbm, lbf, oF, s, V, A

radians [rad]

(Bin) Table 7: Angular Acceleration Unit System

Measured in . . .

o

radians/second2 [rad/s2]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

radians/second2 [rad/s2]

(cgs) mm, kg, N, oC, s, mV, mA

radians/second2 [rad/s2]

(nmm) mm, t, N, oC, s, mV, mA

radians/second2 [rad/s2]

(nmmton) mm, dat, N, oC, s, mV, mA

radians/second2 [rad/s2]

(nmmdat) µm, kg, µN, oC, s, V, mA

radians/second2 [rad/s2]

(µmks) ft, lbm, lbf, oF, s, V, A

radians/second2 [rad/s2]

(Bft) in, lbm, lbf, oF, s, V, A

radians/second2 [rad/s2]

(Bin) Table 8: Angular Velocity Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

radians/second [rad/s]

(mks) cm, g, dyne, oC, s, V, A

radians/second [rad/s]

(cgs) mm, kg, N, oC, s, mV, mA

radians/second [rad/s]

(nmm) mm, t, N, oC, s, mV, mA

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radians/second [rad/s]

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Solving Units Unit System

Measured in . . .

(nmmton) mm, dat, N, oC, s, mV, mA

radians/second [rad/s]

(nmmdat) µm, kg, µN, oC, s, V, mA

radians/second [rad/s]

(µmks) ft, lbm, lbf, oF, s, V, A

radians/second [rad/s]

(Bft) in, lbm, lbf, oF, s, V, A

radians/second [rad/s]

(Bin) mm, mg, ms

radians/millisecond [rad/ms]

[ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

radians/second [rad/s]

[ LS-DYNA solver] mm, t, s

radians/second [rad/s]

[ LS-DYNA solver] in,lbf, s

radians/second [rad/s]

[ LS-DYNA solver] Table 9: Area Unit System

Measured in . . .

o

meters2 [m2]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

centimeters2 [cm2]

(cgs) mm, kg, N, oC, s, mV, mA

millimeters2 [mm2]

(nmm) mm, t, N, oC, s, mV, mA

millimeters2 [mm2]

(nmmton) mm, dat, N, oC, s, mV, mA

millimeters2 [mm2]

(nmmdat) µm, kg, µN, oC, s, V, mA

micrometers2 [µm2]

(µmks)

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1075

Understanding Solving Unit System

Measured in . . .

o

feet2 [ft2]

ft, lbm, lbf, F, s, V, A (Bft) in, lbm, lbf, oF, s, V, A

inches2 [in2]

(Bin) millimeters2 [mm2]

mm, mg, ms [ANSYS (AUTODYN) and LS-DYNA solvers]

meters2 [m2]

m, kg, s [ LS-DYNA solver]

millimeters2 [mm2]

mm, t, s [ LS-DYNA solver]

inches2 [in2]

in,lbf, s [ LS-DYNA solver] Table 10: Capacitance Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Farads [F]

(mks) cm, g, dyne, oC, s, V, A

Farads [F]

(cgs) mm, kg, N, oC, s, mV, mA

microFarads [µF]

(nmm) mm, t, N, oC, s, mV, mA

microFarads [µF]

(nmmton) mm, dat, N, oC, s, mV, mA

microFarads [µF]

(nmmdat) µm, kg, µN, oC, s, V, mA

picoFarads [pF]

(µmks) ft, lbm, lbf, oF, s, V, A

Farads [F]

(Bft)

1076

Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

Solving Units Unit System

Measured in . . .

o

in, lbm, lbf, F, s, V, A

Farads [F]

(Bin) Table 11: Charge Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Coulombs [C]

(mks) cm, g, dyne, oC, s, V, A

Coulombs [C]

(cgs) mm, kg, N, oC, s, mV, mA

milliCoulombs [mC]

(nmm) mm, t, N, oC, s, mV, mA

milliCoulombs [mC]

(nmmton) mm, dat, N, oC, s, mV, mA

milliCoulombs [mC]

(nmmdat) µm, kg, µN, oC, s, V, mA

picoCoulombs [pC]

(µmks) ft, lbm, lbf, oF, s, V, A

Coulombs [C]

(Bft) in, lbm, lbf, oF, s, V, A

Coulombs [C]

(Bin) Table 12: Charge Density Unit System

Measured in . . .

o

Coulombs/meter2 [C/m2]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

Coulombs/centimeter2 [C/cm2]

(cgs) mm, kg, N, oC, s, mV, mA

milliCoulombs/millimeter2 [mC/mm2]

(nmm) mm, t, N, oC, s, mV, mA

milliCoulombs/millimeter2 [mC/mm2]

(nmmton) mm, dat, N, oC, s, mV, mA

milliCoulombs/millimeter2 [mC/mm2]

Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

1077

Understanding Solving Unit System

Measured in . . .

(nmmdat) µm, kg, µN, oC, s, V, mA

picoCoulombs/micrometer2 [pC/µm2]

(µmks) ft, lbm, lbf, oF, s, V, A

Coulombs/foot2 [C/ft2]

(Bft) in, lbm, lbf, oF, s, V, A

Coulombs/inch2 [C/in2]

(Bin) Table 13: Conductivity Unit System

Measured in . . .

o

Watts/meter * degree Celsius [W/m * oC]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

dynes/second * degree Celsius [dyne/s * oC]

(cgs) mm, kg, N, oC, s, mV, mA (nmm) mm, t, N, oC, s, mV, mA (nmmton) mm, dat, N, oC, s, mV, mA (nmmdat) µm, kg, µN, oC, s, V, mA (µmks) ft, lbm, lbf, oF, s, V, A

ton * millimeters/second3 * degree Celsius [t * mm/s3 * oC] ton * millimeters/second3 * degree Celsius [t * mm/s3 * oC] ton * millimeters/second3 * degree Celsius [t * mm/s3 * oC] picoWatts/micrometers * degree Celsius [pW/µm * oC] slug * feet/second3 * degree Fahrenheit [(lbm/32.2)ft/s3 * oF]

(Bft) in, lbm, lbf, oF, s, V, A

slinch * inches/second3 * degree Fahrenheit [(lbm/386.4)in/s3 * oF]

(Bin) Table 14: Current Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Amperes [A]

(mks) cm, g, dyne, oC, s, V, A

Amperes [A]

(cgs) mm, kg, N, oC, s, mV, mA

1078

milliAmperes [mA]

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Solving Units Unit System

Measured in . . .

(nmm) mm, t, N, oC, s, mV, mA

milliAmperes [mA]

(nmmton) mm, dat, N, oC, s, mV, mA

milliAmperes [mA]

(nmmdat) µm, kg, µN, oC, s, V, mA

picoAmperes [pA]

(µmks) ft, lbm, lbf, oF, s, V, A

Amperes [A]

(Bft) in, lbm, lbf, oF, s, V, A

Amperes [A]

(Bin) Table 15: Current Density Unit System

Measured in . . .

o

Amperes/meter2 [A/m2]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

Amperes/centimeter2 [A/cm2]

(cgs) mm, kg, N, oC, s, mV, mA

milliAmperes/millimeter2 [mA/mm2]

(nmm) mm, t, N, oC, s, mV, mA

milliAmperes/millimeter2 [mA/mm2]

(nmmton) mm, dat, N, oC, s, mV, mA

milliAmperes/millimeter2 [mA/mm2]

(nmmdat) µm, kg, µN, oC, s, V, mA

picoAmperes/micrometer2 [pA/µm2]

(µmks) ft, lbm, lbf, oF, s, V, A

Amperes/foot2 [A/ft2]

(Bft) in, lbm, lbf, oF, s, V, A

Amperes/inch2 [A/in2]

(Bin) Table 16: Decay Constant Unit System o

m, kg, N, C, s, V, A

Measured in . . . 1/seconds [1/s] Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

1079

Understanding Solving Unit System

Measured in . . .

(mks) cm, g, dyne, oC, s, V, A

1/seconds [1/s]

(cgs) mm, kg, N, oC, s, mV, mA

1/seconds [1/s]

(nmm) mm, t, N, oC, s, mV, mA

1/seconds [1/s]

(nmmton) mm, dat, N, oC, s, mV, mA

1/seconds [1/s]

(nmmdat) µm, kg, µN, oC, s, V, mA

1/seconds [1/s]

(µmks) ft, lbm, lbf, oF, s, V, A

1/seconds [1/s]

(Bft) in, lbm, lbf, oF, s, V, A

1/seconds [1/s]

(Bin) Table 17: Density Unit System

Measured in . . .

o

kilograms/meter3 [kg/m3]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

grams/cm3 [g/cm3]

(cgs) mm, kg, N, oC, s, mV, mA

tons/millimeter3 [t/mm3]

(nmm) mm, t, N, oC, s, mV, mA

tons/millimeter3 [t/mm3]

(nmmton) mm, dat, N, oC, s, mV, mA

tons/millimeter3 [t/mm3]

(nmmdat) µm, kg, µN, oC, s, V, mA

kilograms/micrometer3 [kg/µm3]

(µmks) ft, lbm, lbf, oF, s, V, A

(slug/1)/foot3 [(lbm/32.2)1/ft3]

(Bft) in, lbm, lbf, oF, s, V, A

1080

(slinch/1)/inch3 [(lbm/386.4)1/in3]

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Solving Units Unit System

Measured in . . .

(Bin) grams/cm3 [g/cm3]

mm, mg, ms [ANSYS (AUTODYN) and LS-DYNA solvers]

kilograms/meter3 [kg/m3]

m, kg, s [ LS-DYNA solver]

tons/millimeter3 [t/mm3]

mm, t, s [ LS-DYNA solver]

(slinch/1)/inch3 [(lbm/386.4)1/in3]

in,lbf, s [ LS-DYNA solver]

Table 18: Displacement and RS Displacement Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

meters [m]

(mks) cm, g, dyne, oC, s, V, A

centimeters [cm]

(cgs) mm, kg, N, oC, s, mV, mA

millimeters [mm]

(nmm) mm, t, N, oC, s, mV, mA

millimeters [mm]

(nmmton) mm, dat, N, oC, s, mV, mA

millimeters [mm]

(nmmdat) µm, kg, µN, oC, s, V, mA

micrometers [µm]

(µmks) ft, lbm, lbf, oF, s, V, A

feet [ft]

(Bft) in, lbm, lbf, oF, s, V, A

inches [in]

(Bin) mm, mg, ms

millimeters [mm]

[ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

meters [m]

[ LS-DYNA solver] Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

1081

Understanding Solving Unit System

Measured in . . .

mm, t, s

millimeters [mm]

[ LS-DYNA solver] in,lbf, s

inches [in]

[ LS-DYNA solver] Table 19: Electric Conductance Per Unit Area Unit System

Measured in . . .

o

Siemens/meter2 [S/m2]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

Siemens/centimeter2 [S/cm2]

(cgs) mm, kg, N, oC, s, mV, mA

Siemens/millimeter2 [S/mm2]

(nmm) mm, t, N, oC, s, mV, mA

Siemens/millimeter2 [S/mm2]

(nmmton) mm, dat, N, oC, s, mV, mA

Siemens/millimeter2 [S/mm2]

(nmmdat) µm, kg, µN, oC, s, V, mA

picoSiemens/micrometer2 [pS/µm2]

(µmks) ft, lbm, lbf, oF, s, V, A

Siemens/foot2 [S/ft2]

(Bft) in, lbm, lbf, oF, s, V, A

Siemens/inch2 [S/in2]

(Bin) Table 20: Electric Conductivity Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Siemens/meter [S/m]

(mks) cm, g, dyne, oC, s, V, A

Siemens/centimeter [S/cm]

(cgs) mm, kg, N, oC, s, mV, mA

Siemens/millimeter [S/mm]

(nmm) mm, t, N, oC, s, mV, mA

1082

Siemens/millimeter [S/mm]

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Solving Units Unit System

Measured in . . .

(nmmton) mm, dat, N, oC, s, mV, mA

Siemens/millimeter [S/mm]

(nmmdat) µm, kg, µN, oC, s, V, mA

picoSiemens/micrometer [pS/µm]

(µmks) ft, lbm, lbf, oF, s, V, A

Siemens/foot [S/ft]

(Bft) in, lbm, lbf, oF, s, V, A

Siemens/inch [S/in]

(Bin) Table 21: Electric Field Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Volts/meter [V/m]

(mks) cm, g, dyne, oC, s, V, A

Volts/centimeter [V/cm]

(cgs) mm, kg, N, oC, s, mV, mA

milliVolts/millimeter [mV/mm]

(nmm) mm, t, N, oC, s, mV, mA

milliVolts/millimeter [mV/mm]

(nmmton) mm, dat, N, oC, s, mV, mA

milliVolts/millimeter [mV/mm]

(nmmdat) µm, kg, µN, oC, s, V, mA

Volts/micrometer [V/µm]

(µmks) ft, lbm, lbf, oF, s, V, A

Volts/foot [V/ft]

(Bft) in, lbm, lbf, oF, s, V, A

Volts/inch [V/in]

(Bin) Table 22: Electric Flux Density Unit System

Measured in . . .

o

Coulombs/meter2 [C/m2]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

Coulombs/centimeter2 [C/cm2]

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1083

Understanding Solving Unit System

Measured in . . .

(cgs) mm, kg, N, oC, s, mV, mA

milliCoulombs/millimeter2 [mC/mm2]

(nmm) mm, t, N, oC, s, mV, mA

milliCoulombs/millimeter2 [mC/mm2]

(nmmton) mm, dat, N, oC, s, mV, mA

milliCoulombs/millimeter2 [mC/mm2]

(nmmdat) µm, kg, µN, oC, s, V, mA

picoCoulombs/micrometer2 [pC/µm2]

(µmks) ft, lbm, lbf, oF, s, V, A

Coulombs/foot2 [C/ft2]

(Bft) in, lbm, lbf, oF, s, V, A

Coulombs/inch2 [C/in2]

(Bin) Table 23: Electric Resistivity Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Ohm * meters [Ohm * m]

(mks) cm, g, dyne, oC, s, V, A

Ohm * centimeters [Ohm * cm]

(cgs) mm, kg, N, oC, s, mV, mA

Ohm * millimeters [Ohm * mm]

(nmm) mm, t, N, oC, s, mV, mA

Ohm * millimeters [Ohm * mm]

(nmmton) mm, dat, N, oC, s, mV, mA

Ohm * millimeters [Ohm * mm]

(nmmdat) µm, kg, µN, oC, s, V, mA

teraOhm * micrometers [Tohm * µm]

(µmks) ft, lbm, lbf, oF, s, V, A

Ohm * Cir-mils/foot [Ohm * Cir-mil/ft]

(Bft)

1084

Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

Solving Units Unit System

Measured in . . .

o

in, lbm, lbf, F, s, V, A

Ohm * Cir-mils/inch [Ohm * Cir-mil/in]

(Bin) Table 24: Energy Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Joules [J]

(mks) cm, g, dyne, oC, s, V, A

ergs [erg]

(cgs) mm, kg, N, oC, s, mV, mA

milliJoules [mJ]

(nmm) mm, t, N, oC, s, mV, mA

milliJoules [mJ]

(nmmton) mm, dat, N, oC, s, mV, mA

milliJoules [mJ]

(nmmdat) µm, kg, µN, oC, s, V, mA

picoJoules [pJ]

(µmks) ft, lbm, lbf, oF, s, V, A

slug * feet2/second2 [(lbm/32.2)ft2/s2]

(Bft) in, lbm, lbf, oF, s, V, A

slinch * inches2/second2 [(lbm/386.4)in2/s2]

(Bin) mm, mg, ms

microJoules [µJ]

[ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

Joules [J]

[ LS-DYNA solver] mm, t, s

milliJoules [mJ]

[ LS-DYNA solver] slinch * inches2/second2 [(lbm/386.4)in2/s2]

in,lbf, s [ LS-DYNA solver] Table 25: Energy Density by Mass Unit System o

m, kg, N, C, s, V, A

Measured in . . . Joules/kilograms [J/kg] Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

1085

Understanding Solving Unit System

Measured in . . .

(mks) cm, g, dyne, oC, s, V, A

dynes * centimeters/grams [dyne * cm /g]

(cgs) mm, kg, N, oC, s, mV, mA

milliJoules/tons [mJ/t]

(nmm) mm, t, N, oC, s, mV, mA

milliJoules/tons [mJ/t]

(nmmton) mm, dat, N, oC, s, mV, mA

milliJoules/tons [mJ/t]

(nmmdat) µm, kg, µN, oC, s, V, mA

picoJoules/kilograms [pJ/kg]

(µmks) ft, lbm, lbf, oF, s, V, A

feet2 /seconds2 [ft2/s2]

(Bft) in, lbm, lbf, oF, s, V, A

inches2/seconds2 [in2/sec 2]

(Bin) mm, mg, ms

Joules/kilograms [J/kg]

[ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

Joules/kilograms [J/kg]

[ LS-DYNA solver] mm, t, s

milliJoules/tons [mJ/t]

[ LS-DYNA solver] inches2/seconds2 [in2/sec 2]

in,lbf, s [ LS-DYNA solver] Table 26: Energy Per Volume Unit System

Measured in . . .

o

Joules/meter3 [J/m3]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

ergs/centimeter3 [erg/cm3]

(cgs) mm, kg, N, oC, s, mV, mA

milliJoules/millimeter3 [mJ/mm3]

(nmm)

1086

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Solving Units Unit System

Measured in . . .

o

mm, t, N, C, s, mV, mA

milliJoules/millimeter3 [mJ/mm3]

(nmmton) mm, dat, N, oC, s, mV, mA

milliJoules/millimeter3 [mJ/mm3]

(nmmdat) µm, kg, µN, oC, s, V, mA

picoJoules/micrometer3 [pJ * um3]

(µmks) ft, lbm, lbf, oF, s, V, A

slug * foot2/second2 * feet3[(lbm/32.2) * ft2/s2 * ft3]

(Bft) in, lbm, lbf, oF, s, V, A

slinch * inch2/second2 * inch3 [(lbm/386.4) * in2/s2 * in3)]

(Bin) Table 27: Film Coefficient Unit System

Measured in . . .

m, kg, N, oC, s, V, A

Watts/meter2 * degree Celsius [W/m2 * oC]

(mks) cm, g, dyne, oC, s, V, A (cgs) mm, kg, N, oC, s, mV, mA

dynes/second * centimeter.degree Celsius [dyne/s * cm * oC] tons/second3 * degree Celsius [t/s3 * oC]

(nmm) mm, t, N, oC, s, mV, mA

tons/second3 * degree Celsius [t/s3 * oC]

(nmmton) mm, dat, N, oC, s, mV, mA

tons/second3 * degree Celsius [t/s3 * oC]

(nmmdat) µm, kg, µN, oC, s, V, mA (µmks) ft, lbm, lbf, oF, s, V, A (Bft) in, lbm, lbf, oF, s, V, A (Bin)

picoWatts/micrometer2 * degree Celsius [pW/µm2 * oC] (slug/1)/second3 * degree Fahrenheit [(lbm/32.2)1/s3 * oF] (slinch/1)/second3 * degree Fahrenheit [(lbm/386.4)1/s3 * oF]

Table 28: Force Unit System o

m, kg, N, C, s, V, A

Measured in . . . Newtons [N]

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1087

Understanding Solving Unit System

Measured in . . .

(mks) cm, g, dyne, oC, s, V, A

dynes [dyne]

(cgs) mm, kg, N, oC, s, mV, mA

ton * millimeters/second2 [t * mm/s2]

(nmm) mm, t, N, oC, s, mV, mA

ton * millimeters/second2 [t * mm/s2]

(nmmton) mm, dat, N, oC, s, mV, mA

ton * millimeters/second2 [t * mm/s2]

(nmmdat) µm, kg, µN, oC, s, V, mA

microNewtons [µN]

(µmks) ft, lbm, lbf, oF, s, V, A

slug * feet/second2 [(lbm/32.2)ft/s2]

(Bft) in, lbm, lbf, oF, s, V, A

slinch * inches/second2 [(lbm/386.4)in/s2]

(Bin) mm, mg, ms

milliNewtons [mN]

[ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

Newtons [N]

[ LS-DYNA solver] mm, t, s

Newtons [N]

[ LS-DYNA solver] in,lbf, s

pound force (lbf )

[ LS-DYNA solver] Table 29: Force Intensity Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Newtons/meter [N/m]

(mks) cm, g, dyne, oC, s, V, A

dynes/centimeter [dyne/cm]

(cgs) mm, kg, N, oC, s, mV, mA

tons/second2 [t/s2]

(nmm)

1088

Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

Solving Units Unit System

Measured in . . .

o

mm, t, N, C, s, mV, mA

tons/second2 [t/s2]

(nmmton) mm, dat, N, oC, s, mV, mA

tons/second2 [t/s2]

(nmmdat) µm, kg, µN, oC, s, V, mA

microNewtons/micrometer [µN/µm]

(µmks) ft, lbm, lbf, oF, s, V, A

(slug/1)/second2 [(lbm/32.2)1/s2]

(Bft) in, lbm, lbf, oF, s, V, A

(slinch/1)/second2 [(lbm/386.4)1/s2]

(Bin) mm, mg, ms [ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

Newtons/meter [N/m] or milliNewtons/millimeter [mN/mm]

Newtons/meter [N/m]

[ LS-DYNA solver] mm, t, s

Newtons/millimeter [N/mm]

[ LS-DYNA solver] in,lbf, s

pound force/inch [lbf/in]

[ LS-DYNA solver] Table 30: Force Per Angular Unit Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Newtons/radian [N/rad]

(mks) cm, g, dyne, oC, s, V, A

dynes/radian [dyne/rad]

(cgs) mm, kg, N, oC, s, mV, mA

Newtons/radian [N/rad]

(nmm) mm, t, N, oC, s, mV, mA

Newtons/radian [N/rad]

(nmmton) mm, dat, N, oC, s, mV, mA

Newtons/radian [N/rad]

(nmmdat) µm, kg, µN, oC, s, V, mA

microNewtons/radian [µN/rad]

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1089

Understanding Solving Unit System

Measured in . . .

(µmks) ft, lbm, lbf, oF, s, V, A

pounds mass/radian [lbf/rad]

(Bft) in, lbm, lbf, oF, s, V, A

pounds mass/radian [lbf/rad]

(Bin) Table 31: Fracture Energy (Energy Release Rate) Unit System

Measured in . . .

o

Joules/meter2 [J/m2]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

erg/centimeter2 [erg/cm2]

(cgs) mm, kg, N, oC, s, mV, mA

milliJoules/millimeter2 [mJ/mm2]

(nmm) mm, t, N, oC, s, mV, mA

milliJoules/millimeter2 [mJ/mm2]

(nmmton) mm, dat, N, oC, s, mV, mA

milliJoules/millimeter2 [mJ/mm2]

(nmmdat) µm, kg, µN, oC, s, V, mA

picoJoules/micrometer2 [pJ/µm2]

(µmks) ft, lbm, lbf, oF, s, V, A

slug * feet2/seconds2 * feet2 [(lbm-ft2)/(s2) * ft2

(Bft) in, lbm, lbf, oF, s, V, A

slinch * inch2/seconds2 * inch2 [(lbm-in2)/(s2) * in2

(Bin) Table 32: Frequency Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Hertz[Hz]

(mks) cm, g, dyne, oC, s, V, A

Hertz[Hz]

(cgs) mm, kg, N, oC, s, mV, mA

Hertz[Hz]

(nmm) mm, t, N, oC, s, mV, mA

1090

Hertz[Hz]

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Solving Units Unit System

Measured in . . .

(nmmton) mm, dat, N, oC, s, mV, mA

Hertz[Hz]

(nmmdat) µm, kg, µN, oC, s, V, mA

Hertz[Hz]

(µmks) ft, lbm, lbf, oF, s, V, A

Hertz[Hz]

(Bft) in, lbm, lbf, oF, s, V, A

Hertz[Hz]

(Bin) Table 33: Gasket Stiffness Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Pascals/meter [Pa/m]

(mks) cm, g, dyne, oC, s, V, A

dynes/centimeter3 [dyne/cm3]

(cgs) mm, kg, N, oC, s, mV, mA

tons/second2 * millimeter2 [t/s2 * mm2]

(nmm) mm, t, N, oC, s, mV, mA

tons/second2 * millimeter2 [t/s2 * mm2]

(nmmton) mm, dat, N, oC, s, mV, mA

tons/second2 * millimeter2 [t/s2 * mm2]

(nmmdat) µm, kg, µN, oC, s, V, mA

megaPascals/micrometer [MPa/µm]

(µmks) ft, lbm, lbf, oF, s, V, A

slug/second2 * foot2 [(lbm/32.2)/s2 * ft2]

(Bft) in, lbm, lbf, oF, s, V, A

slinch/second2 * inch2 [(lbm/386.4)/s2 * in2]

(Bin) Table 34: Heat Flux Unit System

Measured in . . .

o

Watts/meter2 [W/m2]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

dynes/second * centimeter [dyne/s * cm]

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1091

Understanding Solving Unit System

Measured in . . .

(cgs) mm, kg, N, oC, s, mV, mA

tons/second3 [t/s3]

(nmm) mm, t, N, oC, s, mV, mA

tons/second3 [t/s3]

(nmmton) mm, dat, N, oC, s, mV, mA

tons/second3 [t/s3]

(nmmdat) µm, kg, µN, oC, s, V, mA

picoWatts/micrometer2 [pW/µm2]

(µmks) ft, lbm, lbf, oF, s, V, A

(slug/1)/second3 [(lbm/32.2)1/s3]

(Bft) in, lbm, lbf, oF, s, V, A

(slinch/1)/second3 [(lbm/386.4)1/s3]

(Bin) Table 35: Heat Generation Unit System

Measured in . . .

o

Watts/meter3 [W/m3]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

dynes/second * centimeter2 [dyne/s * cm2]

(cgs) mm, kg, N, oC, s, mV, mA

tons/second3 * millimeter [t/s3 * mm]

(nmm) mm, t, N, oC, s, mV, mA

tons/second3 * millimeter [t/s3 * mm]

(nmmton) mm, dat, N, oC, s, mV, mA

tons/second3 * millimeter [t/s3 * mm]

(nmmdat) µm, kg, µN, oC, s, V, mA

picoWatts/micrometer3 [pW/µm3]

(µmks) ft, lbm, lbf, oF, s, V, A

(slug/1)/second3 * foot [(lbm/32.2)1/s3 * ft]

(Bft)

1092

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Solving Units Unit System

Measured in . . .

o

(slinch/1)/second3 * inch [(lbm/386.4)1/s3 * in]

in, lbm, lbf, F, s, V, A (Bin) Table 36: Heat Rate Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Watts [W]

(mks) cm, g, dyne, oC, s, V, A

dyne * centimeters/second [dyne * cm/s]

(cgs) mm, kg, N, oC, s, mV, mA

ton * millimeters2/second3 [t * mm2/s3]

(nmm) mm, t, N, oC, s, mV, mA

ton * millimeters2/second3 [t * mm2/s3]

(nmmton) mm, dat, N, oC, s, mV, mA

ton * millimeters2/second3 [t * mm2/s3]

(nmmdat) µm, kg, µN, oC, s, V, mA

picoWatts [pW]

(µmks) ft, lbm, lbf, oF, s, V, A

slug * feet2/second3 [(lbm/32.2) * ft2/s3]

(Bft) in, lbm, lbf, oF, s, V, A

slinch * inches2/second3 [(lbm/386.4) * in2/s3]

(Bin) Table 37: Impulse Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Newton * second [N * s]

(mks) cm, g, dyne, oC, s, V, A

dyne * second [dyne * s]

(cgs) mm, kg, N, oC, s, mV, mA

Newton * second [N * s]

(nmm) mm, t, N, oC, s, mV, mA

Newton * second [N * s]

(nmmton) mm, dat, N, oC, s, mV, mA

Newton * second [N * s]

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1093

Understanding Solving Unit System

Measured in . . .

(nmmdat) µm, kg, µN, oC, s, V, mA

microNewton * second [µN * s]

(µmks) ft, lbm, lbf, oF, s, V, A

pounds mass * second [lbf * s]

(Bft) in, lbm, lbf, oF, s, V, A

pounds mass * second [lbf * s]

(Bin) mm, mg, ms

microNewton * second [µN * s]

[ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

Newton * second [N * s]

[ LS-DYNA solver] mm, t, s

Newton * second [N * s]

[ LS-DYNA solver] in,lbf, s

pound force * second (lbf * second)

[ LS-DYNA solver] Table 38: Impulse Per Angular Unit Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Newton * second/rad [N * s/rad]

(mks) cm, g, dyne, oC, s, V, A

dyne * second/radian [dyne * s/rad]

(cgs) mm, kg, N, oC, s, mV, mA

Newton * second/rad [N * s/rad]

(nmm) mm, t, N, oC, s, mV, mA

Newton * second/rad [N * s/rad]

(nmmton) mm, dat, N, oC, s, mV, mA

Newton * second/rad [N * s/rad]

(nmmdat) µm, kg, µN, oC, s, V, mA

microNewton * second/radian [µN * s/rad]

(µmks) ft, lbm, lbf, oF, s, V, A

pounds mass * second/radian [lbf * s/rad]

(Bft)

1094

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Solving Units Unit System

Measured in . . .

o

in, lbm, lbf, F, s, V, A

pounds mass * second/radian [lbf * s/rad]

(Bin) Table 39: Inductance Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Henries [H]

(mks) cm, g, dyne, oC, s, V, A

Henries [H]

(cgs) mm, kg, N, oC, s, mV, mA

milliHenries [mH]

(nmm) mm, t, N, oC, s, mV, mA

milliHenries [mH]

(nmmton) mm, dat, N, oC, s, mV, mA

milliHenries [mH]

(nmmdat) µm, kg, µN, oC, s, V, mA

teraHenries [TH]

(µmks) ft, lbm, lbf, oF, s, V, A

Henries [H]

(Bft) in, lbm, lbf, oF, s, V, A

Henries [H]

(Bin) Table 40: Inverse Angle Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

1/radians [1/rad]

(mks) cm, g, dyne, oC, s, V, A

1/radians [1/rad]

(cgs) mm, kg, N, oC, s, mV, mA

1/radians [1/rad]

(nmm) mm, t, N, oC, s, mV, mA

1/radians [1/rad]

(nmmton) mm, dat, N, oC, s, mV, mA

1/radians [1/rad]

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1095

Understanding Solving Unit System

Measured in . . .

(nmmdat) µm, kg, µN, oC, s, V, mA

1/radians [1/rad]

(µmks) ft, lbm, lbf, oF, s, V, A

1/radians [1/rad]

(Bft) in, lbm, lbf, oF, s, V, A

1/radians [1/rad]

(Bin)

Note The units presented above are applicable when the Units menu is set to Radians. The applicable units are 1/degree [1/o] when the Units menu is set to Degrees. Table 41: Inverse Length Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

1/meter [1/m]

(mks) cm, g, dyne, oC, s, V, A

1/centimeter [1/cm]

(cgs) mm, kg, N, oC, s, mV, mA

1/millimeter [1/mm]

(nmm) mm, t, N, oC, s, mV, mA

1/millimeter [1/mm]

(nmmton) mm, dat, N, oC, s, mV, mA

1/millimeter [1/mm]

(nmmdat) µm, kg, µN, oC, s, V, mA

1/micrometer [1/µm]

(µmks) ft, lbm, lbf, oF, s, V, A

1/foot [1/ft]

(Bft) in, lbm, lbf, oF, s, V, A

1/inch [1/in]

(Bin) Table 42: Inverse Stress Unit System o

m, kg, N, C, s, V, A

1096

Measured in . . . 1/Pascal [1/Pa] Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

Solving Units Unit System

Measured in . . .

(mks) cm, g, dyne, oC, s, V, A

centimeters2/dyne [cm2/dyne]

(cgs) mm, kg, N, oC, s, mV, mA

second2 * millimeters/ton [s2 * mm/t]

(nmm) mm, t, N, oC, s, mV, mA

second2 * millimeters/ton [s2 * mm/t]

(nmmton) mm, dat, N, oC, s, mV, mA

second2 * millimeters/ton [s2 * mm/t]

(nmmdat) µm, kg, µN, oC, s, V, mA

1/megaPascal [1/MPa]

(µmks) ft, lbm, lbf, oF, s, V, A

second2 * feet/slug [s2 * ft/(lbm/32.2)]

(Bft) in, lbm, lbf, oF, s, V, A

second2 * inch/slinch [s2 * in/(lbm/386.4)]

(Bin) Table 43: Length Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

meters [m]

(mks) cm, g, dyne, oC, s, V, A

centimeters [cm]

(cgs) mm, kg, N, oC, s, mV, mA

millimeters [mm]

(nmm) mm, t, N, oC, s, mV, mA

millimeters [mm]

(nmmton) mm, dat, N, oC, s, mV, mA

millimeters [mm]

(nmmdat) µm, kg, µN, oC, s, V, mA

micrometers [µm]

(µmks) ft, lbm, lbf, oF, s, V, A

feet [ft]

(Bft) in, lbm, lbf, oF, s, V, A

inches [in]

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1097

Understanding Solving Unit System

Measured in . . .

(Bin) mm, mg, ms

millimeters [mm]

[ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

meters [m]

[ LS-DYNA solver] mm, t, s

millimeters [mm]

[ LS-DYNA solver] in,lbf, s

inches [in]

[ LS-DYNA solver] Table 44: Magnetic Field Intensity Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Amperes/meter [A/m]

(mks) cm, g, dyne, oC, s, V, A

Oersteds [Oe]

(cgs) mm, kg, N, oC, s, mV, mA

milliAmperes/millimeter [mA/mm]

(nmm) mm, t, N, oC, s, mV, mA

milliAmperes/millimeter [mA/mm]

(nmmton) mm, dat, N, oC, s, mV, mA

milliAmperes/millimeter [mA/mm]

(nmmdat) µm, kg, µN, oC, s, V, mA

picoAmperes/micrometer [pA/µm]

(µmks) ft, lbm, lbf, oF, s, V, A

Amperes/foot [A/ft]

(Bft) in, lbm, lbf, oF, s, V, A

Amperes/inch [A/in]

(Bin) Table 45: Magnetic Flux Unit System o

m, kg, N, C, s, V, A

Measured in . . . Webers [Wb]

(mks)

1098

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Solving Units Unit System

Measured in . . . o

cm, g, dyne, C, s, V, A

Maxwells [Mx]

(cgs) mm, kg, N, oC, s, mV, mA

milliWebers [mWb]

(nmm) mm, t, N, oC, s, mV, mA

milliWebers [mWb]

(nmmton) mm, dat, N, oC, s, mV, mA

milliWebers [mWb]

(nmmdat) µm, kg, µN, oC, s, V, mA

Webers [Wb]

(µmks) ft, lbm, lbf, oF, s, V, A

Lines

(Bft) in, lbm, lbf, oF, s, V, A

Lines

(Bin) Table 46: Magnetic Flux Density Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Teslas [T]

(mks) cm, g, dyne, oC, s, V, A

Gauss [G]

(cgs) mm, kg, N, oC, s, mV, mA

milliTeslas [mT]

(nmm) mm, t, N, oC, s, mV, mA

milliTeslas [mT]

(nmmton) mm, dat, N, oC, s, mV, mA

milliTeslas [mT]

(nmmdat) µm, kg, µN, oC, s, V, mA

teraTeslas [TT]

(µmks) ft, lbm, lbf, oF, s, V, A

Lines/foot2 [lines/ft2]

(Bft)

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1099

Understanding Solving Unit System

Measured in . . .

o

Lines/inch2 [lines/in2]

in, lbm, lbf, F, s, V, A (Bin) Table 47: Mass Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

kilograms [kg]

(mks) cm, g, dyne, oC, s, V, A

grams [g]

(cgs) mm, kg, N, oC, s, mV, mA

tons [t]

(nmm) mm, t, N, oC, s, mV, mA

tons [t]

(nmmton) mm, dat, N, oC, s, mV, mA

tons [t]

(nmmdat) µm, kg, µN, oC, s, V, mA

kilograms [kg]

(µmks) ft, lbm, lbf, oF, s, V, A

slug [lbm/32.2]

(Bft) in, lbm, lbf, oF, s, V, A

slinch [lbm/386.4]

(Bin) mm, mg, ms

milligrams [mg]

[ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

kilograms [kg]

[ LS-DYNA solver] mm, t, s

tons [t]

[ LS-DYNA solver] in,lbf, s

slinch [lbm/386.4]

[ LS-DYNA solver] Table 48: Material Impedance Unit System

Measured in . . .

mm, mg, ms

milligrams/millimeter2/second [mg/mm2/s]

1100

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Solving Units Unit System

Measured in . . .

[ANSYS (AUTODYN) and LS-DYNA solvers] kilograms/meter2/second [kg/m2/s]

m, kg, s [ LS-DYNA solver]

tons/millimeter2/second [t/mm2/s]

mm, t, s [ LS-DYNA solver]

slinch/inch2/second [slinch/in2/s]

in,lbf, s [ LS-DYNA solver] Table 49: Moment Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Newton * meters [N * m]

(mks) cm, g, dyne, oC, s, V, A

dyne * centimeters [dyne * cm]

(cgs) mm, kg, N, oC, s, mV, mA

ton * millimeters2/second2 [t * mm2/s2]

(nmm) mm, t, N, oC, s, mV, mA

ton * millimeters2/second2 [t * mm2/s2]

(nmmton) mm, dat, N, oC, s, mV, mA

ton * millimeters2/second2 [t * mm2/s2]

(nmmdat) µm, kg, µN, oC, s, V, mA

microNewton * micrometers [µN * µm]

(µmks) ft, lbm, lbf, oF, s, V, A

slug * feet2/second2 [(lbm/32.2) * ft2/s2]

(Bft) in, lbm, lbf, oF, s, V, A

slinch * inches2/second2 [(lbm/386.4) * in2/s2]

(Bin) mm, mg, ms

microNewton * meters [µN * m]

[ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

Newton * meters [N * m]

[ LS-DYNA solver] mm, t, s

Newton * millimeters [N * mm]

[ LS-DYNA solver] Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

1101

Understanding Solving Unit System

Measured in . . .

in,lbf, s

pound force * inch [lbf * in]

[ LS-DYNA solver] Table 50: Moment of Inertia of Area Unit System

Measured in . . .

o

meters4 [m4]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

centimeters4 [cm4]

(cgs) mm, kg, N, oC, s, mV, mA

millimeters4 [mm4]

(nmm) mm, t, N, oC, s, mV, mA

millimeters4 [mm4]

(nmmton) mm, dat, N, oC, s, mV, mA

millimeters4 [mm4]

(nmmdat) µm, kg, µN, oC, s, V, mA

micrometers4 [µm4]

(µmks) ft, lbm, lbf, oF, s, V, A

feet4 [ft4]

(Bft) in, lbm, lbf, oF, s, V, A

inches4 [in4]

(Bin) millimeters4 [mm4]

mm, mg, ms [ANSYS (AUTODYN) and LS-DYNA solvers]

meters4 [m4]

m, kg, s [ LS-DYNA solver]

millimeters4 [mm4]

mm, t, s [ LS-DYNA solver]

inches4 [in4]

in,lbf, s [ LS-DYNA solver] Table 51: Moment of Inertia of Mass Unit System o

m, kg, N, C, s, V, A

1102

Measured in . . . kilogram * meter2 [kg * m2] Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

Solving Units Unit System

Measured in . . .

(mks) cm, g, dyne, oC, s, V, A

gram * centimeter2 [g * cm2]

(cgs) mm, kg, N, oC, s, mV, mA

kilogram * millimeter2 [kg * mm2]

(nmm) mm, t, N, oC, s, mV, mA

kilogram * millimeter2 [kg * mm2]

(nmmton) mm, dat, N, oC, s, mV, mA

kilogram * millimeter2 [kg * mm2]

(nmmdat) µm, kg, µN, oC, s, V, mA

kilogram * micrometer2 [kg * µm2]

(µmks) ft, lbm, lbf, oF, s, V, A

slug * feet2 [(lbm/32.2) * ft2]

(Bft) in, lbm, lbf, oF, s, V, A

slinch * inch2 [(lbm/386.4) * in2]

(Bin) milligram * millimeter2 [mg * mm2]

mm, mg, ms [ANSYS (AUTODYN) and LS-DYNA solvers]

kilogram * meter2 [kg * m2]

m, kg, s [ LS-DYNA solver]

ton * millimeter2 [t * mm2]

mm, t, s [ LS-DYNA solver]

slinch * inch2 [slinch * in2]

in,lbf, s [ LS-DYNA solver] Table 52: Normalized Value Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

unitless

(mks) cm, g, dyne, oC, s, V, A

unitless

(cgs) mm, kg, N, oC, s, mV, mA

unitless

(nmm)

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1103

Understanding Solving Unit System

Measured in . . .

o

mm, t, N, C, s, mV, mA

unitless

(nmmton) mm, dat, N, oC, s, mV, mA

unitless

(nmmdat) µm, kg, µN, oC, s, V, mA

unitless

(µmks) ft, lbm, lbf, oF, s, V, A

unitless

(Bft) in, lbm, lbf, oF, s, V, A

unitless

(Bin) Table 53: Permeability Unit System

Measured in . . .

m, kg, N, oC, s, V, A

Henries/meter [H/m]

(mks) cm, g, dyne, oC, s, V, A

Henries/centimeter [H/cm]

(cgs) mm, kg, N, oC, s, mV, mA

milliHenries/millimeter [mH/mm]

(nmm) mm, t, N, oC, s, mV, mA

milliHenries/millimeter [mH/mm]

(nmmton) mm, dat, N, oC, s, mV, mA

milliHenries/millimeter [mH/mm]

(nmmdat) µm, kg, µN, oC, s, V, mA

teraHenries/micrometer [TH/µm]

(µmks) ft, lbm, lbf, oF, s, V, A

Henries/foot [H/ft]

(Bft) in, lbm, lbf, oF, s, V, A

Henries/inch [H/in]

(Bin) Table 54: Permittivity Unit System o

m, kg, N, C, s, V, A

1104

Measured in . . . Farads/meter [F/m]

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Solving Units Unit System

Measured in . . .

(mks) cm, g, dyne, oC, s, V, A

Farads/centimeter [F/cm]

(cgs) mm, kg, N, oC, s, mV, mA

microFarads/millimeter [µF/mm]

(nmm) mm, t, N, oC, s, mV, mA

microFarads/millimeter [µF/mm]

(nmmton) mm, dat, N, oC, s, mV, mA

microFarads/millimeter [µF/mm]

(nmmdat) µm, kg, µN, oC, s, V, mA

picoFarads/micrometer [pF/µm]

(µmks) ft, lbm, lbf, oF, s, V, A

Farads/foot [F/ft]

(Bft) in, lbm, lbf, oF, s, V, A

Farads/inch [F/in]

(Bin) Table 55: Poisson’s Ratio Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

unitless

(mks) cm, g, dyne, oC, s, V, A

unitless

(cgs) mm, kg, N, oC, s, mV, mA

unitless

(nmm) mm, t, N, oC, s, mV, mA

unitless

(nmmton) mm, dat, N, oC, s, mV, mA

unitless

(nmmdat) µm, kg, µN, oC, s, V, mA

unitless

(µmks) ft, lbm, lbf, oF, s, V, A

unitless

(Bft) in, lbm, lbf, oF, s, V, A

unitless

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1105

Understanding Solving Unit System

Measured in . . .

(Bin) mm, mg, ms

unitless

[ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

unitless

[ LS-DYNA solver] mm, t, s

unitless

[ LS-DYNA solver] in,lbf, s

unitless

[ LS-DYNA solver] Table 56: Power Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Watts [W]

(mks) cm, g, dyne, oC, s, V, A

dyne * centimeters/second [dyne * cm/s]

(cgs) mm, kg, N, oC, s, mV, mA

ton * millimeters2/second3 [t * mm2/s3]

(nmm) mm, t, N, oC, s, mV, mA

ton * millimeters2/second3 [t * mm2/s3]

(nmmton) mm, dat, N, oC, s, mV, mA

ton * millimeters2/second3 [t * mm2/s3]

(nmmdat) µm, kg, µN, oC, s, V, mA

picoWatts [pW]

(µmks) ft, lbm, lbf, oF, s, V, A

slug * feet2/second3 [(lbm/32.2) * ft2/s3]

(Bft) in, lbm, lbf, oF, s, V, A

slinch * inches2/second3 [(lbm/386.4) * in2/s3]

(Bin) mm, mg, ms

milliWatts [mW]

[ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

Watts [W]

[ LS-DYNA solver]

1106

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Solving Units Unit System

Measured in . . .

mm, t, s

Newton * millimeters/second [N * mm/s]

[ LS-DYNA solver] in,lbf, s

pound force * inch/second [lbf * in/s]

[ LS-DYNA solver] Table 57: Pressure Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Pascals [Pa]

(mks) cm, g, dyne, oC, s, V, A

dynes/centimeter2 [dyne/cm2]

(cgs) mm, kg, N, oC, s, mV, mA

ton/second2 * millimeters [t/s2 * mm]

(nmm) mm, t, N, oC, s, mV, mA

ton/second2 * millimeters [t/s2 * mm]

(nmmton) mm, dat, N, oC, s, mV, mA

ton/second2 * millimeters [t/s2 * mm]

(nmmdat) µm, kg, µN, oC, s, V, mA

megaPascals [MPa]

(µmks) ft, lbm, lbf, oF, s, V, A

(slug/1)/second2 * foot [(lbm/32.2)1/s2 * ft]

(Bft) in, lbm, lbf, oF, s, V, A

(slinch/1)/second2 * inch [(lbm/386.4)1/s2 * in]

(Bin) mm, mg, ms

kiloPascals [kPa]

[ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

Pascals [Pa]

[ LS-DYNA solver] mm, t, s

megaPascals [MPa]

[ LS-DYNA solver]

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1107

Understanding Solving Unit System

Measured in . . .

in,lbf, s

pounds/inch2 [lb/in2]

[ LS-DYNA solver] Table 58: PSD Acceleration Unit System

Measured in . . .

o

(meters/second2)2/Hertz [(m/s2)2/Hz]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

(centimeters/second2)2/Hertz [(cm/s2)2/Hz]

(cgs) mm, kg, N, oC, s, mV, mA

(millimeters/second2)2/Hertz [(mm/s2)2/Hz]

(nmm) mm, t, N, oC, s, mV, mA

(millimeters/second2)2/Hertz [(mm/s2)2/Hz]

(nmmton) mm, dat, N, oC, s, mV, mA

(millimeters/second2)2/Hertz [(mm/s2)2/Hz]

(nmmdat) µm, kg, µN, oC, s, V, mA (µmks) ft, lbm, lbf, oF, s, V, A

(micrometers/second2)2/megahertz [(µm/s2)2/MHz] (feet/second2)2/Hertz [(ft/s2)2/Hz]

(Bft) in, lbm, lbf, oF, s, V, A

(inch/second2)2/Hertz [(in/s2)2/Hz]

(Bin) Table 59: PSD Acceleration (G) Unit System

Measured in . . .

o

G2/Hertz [G2/Hz]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

G2/Hertz [G2/Hz]

(cgs) mm, kg, N, oC, s, mV, mA

G2/Hertz [G2/Hz]

(nmm) mm, t, N, oC, s, mV, mA

G2/Hertz [G2/Hz]

(nmmton) mm, dat, N, oC, s, mV, mA

1108

G2/Hertz [G2/Hz]

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Solving Units Unit System

Measured in . . .

(nmmdat) µm, kg, µN, oC, s, V, mA

G2/Hertz [G2/Hz]

(µmks) ft, lbm, lbf, oF, s, V, A

G2/Hertz [G2/Hz]

(Bft) in, lbm, lbf, oF, s, V, A

G2/Hertz [G2/Hz]

(Bin) Table 60: PSD Displacement Unit System

Measured in . . .

o

meters2/Hertz [m2/Hz]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

centimeters2/Hertz [cm2/Hz]

(cgs) mm, kg, N, oC, s, mV, mA

millimeters2/Hertz [mm2/Hz]

(nmm) mm, t, N, oC, s, mV, mA

millimeters2/Hertz [mm2/Hz]

(nmmton) mm, dat, N, oC, s, mV, mA

millimeters2/Hertz [mm2/Hz]

(nmmdat) µm, kg, µN, oC, s, V, mA

micrometers2/megaHertz [µm2/MHz]

(µmks) ft, lbm, lbf, oF, s, V, A

feet2/Hertz [ft2/Hz]

(Bft) in, lbm, lbf, oF, s, V, A

inches2/Hertz [in2/Hz]

(Bin) Table 61: PSD Force Unit System

Measured in . . .

o

Newtons2/Hertz [N2/Hz]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

dynes2/Hertz [dyne2/Hz]

(cgs)

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1109

Understanding Solving Unit System

Measured in . . .

o

mm, kg, N, C, s, mV, mA (nmm) mm, t, N, oC, s, mV, mA (nmmton) mm, dat, N, oC, s, mV, mA (nmmdat) µm, kg, µN, oC, s, V, mA

((kilograms.millimeters)/second2)2/Hertz [((kg * mm)/s2)2/Hz] ((tons * millimeters)/second2)2/Hertz [((t * mm)/s2)2s/Hz] ((tons * millimeters)/second2)2/Hertz [((t * mm)/s2)2s/Hz] microNewtons2/Hertz [µN2/Hz]

(µmks) ft, lbm, lbf, oF, s, V, A

((pounds * mass/32.2) * feet)/second2))2/Hertz [((lb * m/32.2) * ft/s2))2/Hz]

(Bft) in, lbm, lbf, oF, s, V, A

((pounds * mass/32.2) * inches)/second2))2/Hertz [((lb * m/32.2) * in/s2))2/Hz]

(Bin) Table 62: PSD Moment Unit System

Measured in . . .

o

(Newtons * meters)2/Hertz [(N * m)2/Hz]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A (cgs) mm, kg, N, oC, s, mV, mA (nmm) mm, t, N, oC, s, mV, mA (nmmton) mm, dat, N, oC, s, mV, mA (nmmdat) µm, kg, µN, oC, s, V, mA (µmks) ft, lbm, lbf, oF, s, V, A (Bft)

1110

(dynes * centimeters)2/Hertz [(dyne * cm)2/Hz] ((kilograms * millimeters2)/Second2)2/Hertz [((kg * mm2)/s2)2/Hz] ((tons * millimeters2)/second2)2/Hertz [((t * mm2)/s2)2/Hz] ((tons * millimeters2)/second2)2/Hertz [((t * mm2)/s2)2/Hz] (microNewtons * micrometers)2/Hertz [(µN * µm)2/Hz] ((pounds * mass/32.2) * feet2)/second2) /Hertz [((lb * m/32.2) * ft2)/s2)2/Hz]

2

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Solving Units Unit System

Measured in . . .

o

in, lbm, lbf, F, s, V, A

((pounds * mass/386.4) * inches2)/second2)2/Hertz [((lb * m/386.4) * in2)/s2)2/Hz]

(Bin) Table 63: PSD Pressure Unit System

Measured in . . .

o

Pascals2/Hertz [Pa2/Hz]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

(dynes/centimeter2)2/Hertz [(dyne/cm2)2/Hz]

(cgs) mm, kg, N, oC, s, mV, mA (nmm) mm, t, N, oC, s, mV, mA (nmmton) mm, dat, N, oC, s, mV, mA (nmmdat) µm, kg, µN, oC, s, V, mA

(kilograms/(millimeter * second2))2/Hertz [(kg/(mm * s2))2/Hz] (tons/(millimeter * second2))2/Hertz [(t/(mm * s2))2/Hz] (tons/(millimeter * second2))2/Hertz [(t/(mm * s2))2/Hz] megaNewtons2/Hertz [MPa2/Hz]

(µmks) ft, lbm, lbf, oF, s, V, A

(slug/(foot * second2))2/Hertz [((lbm/32.2)/(ft * s2))2/Hz]

(Bft) in, lbm, lbf, oF, s, V, A

(slinch/(inch * second2))2/Hertz [((lbm/386.4)/(in * s2))2/Hz]

(Bin) Table 64: PSD Strain Unit System

Measured in . . .

o

(meters/meter)2/Hertz [(m/m)2/Hz]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A (cgs) mm, kg, N, oC, s, mV, mA (nmm) mm, t, N, oC, s, mV, mA (nmmton) mm, dat, N, oC, s, mV, mA

(centimeters/centimeter)2/Hertz [(cm/cm)2/Hz] (millimeters/millimeter)2/Hertz [(mm/mm)2/Hz] (millimeters/millimeter)2/Hertz [(mm/mm)2/Hz] (millimeters/millimeter)2/Hertz [(mm/mm)2/Hz]

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1111

Understanding Solving Unit System

Measured in . . .

(nmmdat) µm, kg, µN, oC, s, V, mA (µmks) ft, lbm, lbf, oF, s, V, A

(micrometers/micrometer)2/Hertz [(µm/µm)2/Hz] (feet/foot)2/Hertz [(ft/ft)2/Hz]

(Bft) in, lbm, lbf, oF, s, V, A

(inches/inch)2/Hertz [(in/in)2/Hz]

(Bin) Table 65: PSD Stress Unit System

Measured in . . .

o

Pascals2/Hertz [Pa2/Hz]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

(dynes/centimeter2)2/Hertz [(dyne/cm2)2/Hz]

(cgs) mm, kg, N, oC, s, mV, mA (nmm) mm, t, N, oC, s, mV, mA (nmmton) mm, dat, N, oC, s, mV, mA (nmmdat) µm, kg, µN, oC, s, V, mA

(kilograms/(millimeter * second2))2/Hertz [(kg/(mm * s2))2/Hz] (tons/(millimeter * second2))2/Hertz [(t/(mm * s2))2/Hz] (tons/(millimeter * second2))2/Hertz [(t/(mm * s2))2/Hz] megaNewtons2/Hertz [MPa2/Hz]

(µmks) ft, lbm, lbf, oF, s, V, A

(slug/(foot * second2))2/Hertz [((lbm/32.2)/(ft * s2))2/Hz]

(Bft) in, lbm, lbf, oF, s, V, A

(slinch/(inch * second2))2/Hertz [((lbm/386.4)/(in * s2))2/Hz]

(Bin) Table 66: PSD Velocity Unit System

Measured in . . .

o

(meters/second)2/Hertz [(m/s)2/Hz]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

(centimeters/second)2/Hertz [(cm/s)2/Hz]

(cgs) mm, kg, N, oC, s, mV, mA

1112

(millimeters/second)2/Hertz [(mm/s)2/Hz]

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Solving Units Unit System

Measured in . . .

(nmm) mm, t, N, oC, s, mV, mA

(millimeters/second)2/Hertz [(mm/s)2/Hz]

(nmmton) mm, dat, N, oC, s, mV, mA

(millimeters/second)2/Hertz [(mm/s)2/Hz]

(nmmdat) µm, kg, µN, oC, s, V, mA (µmks) ft, lbm, lbf, oF, s, V, A

(micrometers/second)2/megahertz [(µm/s)2/MHz] (feet/second)2/Hertz [(ft/s)2/Hz]

(Bft) in, lbm, lbf, oF, s, V, A

(inches/second)2/Hertz [(in/s)2/Hz]

(Bin) Table 67: Relative Permeability Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

unitless

(mks) cm, g, dyne, oC, s, V, A

unitless

(cgs) mm, kg, N, oC, s, mV, mA

unitless

(nmm) mm, t, N, oC, s, mV, mA

unitless

(nmmton) mm, dat, N, oC, s, mV, mA

unitless

(nmmdat) µm, kg, µN, oC, s, V, mA

unitless

(µmks) ft, lbm, lbf, oF, s, V, A

unitless

(Bft) in, lbm, lbf, oF, s, V, A

unitless

(Bin) Table 68: Relative Permittivity Unit System o

m, kg, N, C, s, V, A

Measured in . . . unitless Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

1113

Understanding Solving Unit System

Measured in . . .

(mks) cm, g, dyne, oC, s, V, A

unitless

(cgs) mm, kg, N, oC, s, mV, mA

unitless

(nmm) mm, t, N, oC, s, mV, mA

unitless

(nmmton) mm, dat, N, oC, s, mV, mA

unitless

(nmmdat) µm, kg, µN, oC, s, V, mA

unitless

(µmks) ft, lbm, lbf, oF, s, V, A

unitless

(Bft) in, lbm, lbf, oF, s, V, A

unitless

(Bin) Table 69: Rotational Damping Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Newton * meter * seconds/radian [N * m * s/rad]

(mks) cm, g, dyne, oC, s, V, A (cgs) mm, kg, N, oC, s, mV, mA (nmm) mm, t, N, oC, s, mV, mA (nmmton) mm, dat, N, oC, s, mV, mA (nmmdat) µm, kg, µN, oC, s, V, mA (µmks) ft, lbm, lbf, oF, s, V, A (Bft)

1114

dyne * centimeter * seconds/radian [dyne * cm * s/rad] ton * millimeter2 * seconds/second2 * radian [t * mm2 * s/s2 * rad] ton * millimeter2 * seconds/second2 * radian [t * mm2 * s/s2 * rad] ton * millimeter2 * seconds/second2 * radian [t * mm2 * s/s2 * rad] microNewton * micrometer * seconds/radian [µN * µm * s/rad] slug * foot2 * seconds/second2 * radian [(lbm/32.2) * ft2 * s/s2 * rad]

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Solving Units Unit System

Measured in . . .

o

slinch * inch2 * seconds/second2 * radian [(lbm/386.4) * in2 * s/s2 * rad]

in, lbm, lbf, F, s, V, A (Bin) Table 70: Rotational Stiffness Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Newton * meters/radian [N * m/rad]

(mks) cm, g, dyne, oC, s, V, A

dynes * centimeters/radian [dyne * cm/rad]

(cgs) mm, kg, N, oC, s, mV, mA (nmm) mm, t, N, oC, s, mV, mA (nmmton) mm, dat, N, oC, s, mV, mA (nmmdat) µm, kg, µN, oC, s, V, mA (µmks) ft, lbm, lbf, oF, s, V, A

ton * millimeters2/second2 * radian [t * mm2/s2 * rad] ton * millimeters2/second2 * radian [t * mm2/s2 * rad] ton * millimeters2/second2 * radian [t * mm2/s2 * rad] microNewton * micrometers/radian [µN*µm/rad] slug * feet2/second2 * radian [(lbm/32.2) * ft2/s2 * rad]

(Bft) in, lbm, lbf, oF, s, V, A

slinch * inches2/second2 * radian [(lbm/386.4) * in2/s2 * rad]

(Bin) Table 71: Seebeck Coefficient Unit System

Measured in . . .

o

Volts/degree Celsius [V/oC]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

Volts/degree Celsius [V/oC]

(cgs) mm, kg, N, oC, s, mV, mA

milliVolts/degree Celsius [mV/oC]

(nmm) mm, t, N, oC, s, mV, mA

milliVolts/degree Celsius [mV/oC]

(nmmton) mm, dat, N, oC, s, mV, mA

milliVolts/degree Celsius [mV/oC]

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1115

Understanding Solving Unit System

Measured in . . .

(nmmdat) µm, kg, µN, oC, s, V, mA

Volts/degree Celsius [V/oC]

(µmks) ft, lbm, lbf, oF, s, V, A

Volts/degree Fahrenheit [V/oF]

(Bft) in, lbm, lbf, oF, s, V, A

Volts/degree Fahrenheit [V/oF]

(Bin) Table 72: Section Modulus Unit System

Measured in . . .

o

meters3 [m3]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

centimeters3 [cm3]

(cgs) mm, kg, N, oC, s, mV, mA

millimeters3 [mm3]

(nmm) mm, t, N, oC, s, mV, mA

millimeters3 [mm3]

(nmmton) mm, dat, N, oC, s, mV, mA

millimeters3 [mm3]

(nmmdat) µm, kg, µN, oC, s, V, mA

micrometers3 [µm3]

(µmks) ft, lbm, lbf, oF, s, V, A

feet3 [ft3]

(Bft) in, lbm, lbf, oF, s, V, A

inches3 [in3]

(Bin) millimeters3 [mm3]

mm, mg, ms [ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

meters3 [m3]

[ LS-DYNA solver] mm, t, s

millimeters3 [mm3]

[ LS-DYNA solver]

1116

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Solving Units Unit System

Measured in . . .

in,lbf, s

inch3 [in3]

[ LS-DYNA solver] Table 73: Shear Elastic Strain Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

radians [rad]

(mks) cm, g, dyne, oC, s, V, A

radians [rad]

(cgs) mm, kg, N, oC, s, mV, mA

radians [rad]

(nmm) mm, t, N, oC, s, mV, mA

radians [rad]

(nmmton) mm, dat, N, oC, s, mV, mA

radians [rad]

(nmmdat) µm, kg, µN, oC, s, V, mA

radians [rad]

(µmks) ft, lbm, lbf, oF, s, V, A

radians [rad]

(Bft) in, lbm, lbf, oF, s, V, A

radians [rad]

(Bin) Table 74: Shock Velocity Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

seconds/meters [s/m]

(mks) cm, g, dyne, oC, s, V, A

seconds/centimeters [s/cm]

(cgs) mm, kg, N, oC, s, mV, mA

seconds/millimeters [s/mm]

(nmm) mm, t, N, oC, s, mV, mA

seconds/millimeters [s/mm]

(nmmton) mm, dat, N, oC, s, mV, mA

seconds/millimeters [s/mm]

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1117

Understanding Solving Unit System

Measured in . . .

(nmmdat) µm, kg, µN, oC, s, V, mA

seconds/micrometers [s/µm]

(µmks) ft, lbm, lbf, oF, s, V, A

seconds/feet [s/ft]

(Bft) in, lbm, lbf, oF, s, V, A

seconds/inches [s/in]

(Bin) Table 75: Specific Heat Unit System

Measured in . . .

o

Joules/kilogram * degree Celsius [J/kg * oC]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A (cgs) mm, kg, N, oC, s, mV, mA (nmm) mm, t, N, oC, s, mV, mA (nmmton) mm, dat, N, oC, s, mV, mA (nmmdat) µm, kg, µN, oC, s, V, mA (µmks) ft, lbm, lbf, oF, s, V, A

dyne * centimeters/gram * degree Celsius [dyne*cm/g * oC] millimeters2/second2 * degree Celsius [mm2/s2 * oC] millimeters2/second2 * degree Celsius [mm2/s2 * oC] millimeters2/second2 * degree Celsius [mm2/s2 * oC] picoJoules/kilogram * degree Celsius [pJ/kg * oC] feet2/second2 * degree Fahrenheit [ft2/s2 * F]

o

(Bft) in, lbm, lbf, oF, s, V, A

inches2/second2 * degree Fahrenheit [in2/s2 * oF]

(Bin) Joules/kilogram * degree Kelvin [J/kg * oK]

mm, mg, ms [ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

Joules/kilogram/degree Kelvin [J/kg/oK]

[ LS-DYNA solver] mm, t, s

milliJoules/ton/degree Kelvin [mJ/t/oK]

[ LS-DYNA solver]

1118

Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

Solving Units Unit System

Measured in . . .

in,lbf, s

inch2/second2/oF [in2/s2/oF]

[ LS-DYNA solver] Table 76: Specific Weight Unit System

Measured in . . .

o

Newtons/meter3 [N/m3]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

dynes/centimeter3 [dyne/cm3]

(cgs) mm, kg, N, oC, s, mV, mA

tons/second2 * millimeters2 [t/s2 * mm2]

(nmm) mm, t, N, oC, s, mV, mA

tons/second2 * millimeters2 [t/s2 * mm2]

(nmmton) mm, dat, N, oC, s, mV, mA

tons/second2 * millimeters2 [t/s2 * mm2]

(nmmdat) µm, kg, µN, oC, s, V, mA

microNewtons/micrometer3 [µN/µm3]

(µmks) ft, lbm, lbf, oF, s, V, A

(slug/1)/second2 * feet2 [(lbm/32.2)1/s2 * ft2]

(Bft) in, lbm, lbf, oF, s, V, A

(slinch/1)/second2 * inch2 [(lbm/386.4)1/s2 * in2]

(Bin) megaNewtons/meter3 [MN/m3]

mm, mg, ms [ANSYS (AUTODYN) and LS-DYNA solvers]

Newtons/meter3 [N/m3]

m, kg, s [ LS-DYNA solver]

Newtons/millimeter3 [N/mm3]

mm, t, s [ LS-DYNA solver]

pound force/inch3 [lbf/in3]

in,lbf, s [ LS-DYNA solver] Table 77: Square Root of Length Unit System o

m, kg, N, C, s, V, A

Measured in . . . meter0.5 [m0.5] Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

1119

Understanding Solving Unit System

Measured in . . .

(mks) cm, g, dyne, oC, s, V, A

centimeter0.5 [cm0.5]

(cgs) mm, kg, N, oC, s, mV, mA

millimeter0.5 [mm0.5]

(nmm) mm, t, N, oC, s, mV, mA

millimeter0.5 [mm0.5]

(nmmton) mm, dat, N, oC, s, mV, mA

millimeter0.5 [mm0.5]

(nmmdat) µm, kg, µN, oC, s, V, mA

micrometer0.5 [µm0.5]

(µmks) ft, lbm, lbf, oF, s, V, A

feet0.5 [ft0.5]

(Bft) in, lbm, lbf, oF, s, V, A

inch0.5 [in0.5]

(Bin) Table 78: Stiffness Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Newtons/meter [N/m]

(mks) cm, g, dyne, oC, s, V, A

dynes/centimeter [dyne/cm]

(cgs) mm, kg, N, oC, s, mV, mA

Newtons/millimeter [N/mm]

(nmm) mm, t, N, oC, s, mV, mA

Newtons/millimeter [N/mm]

(nmmton) mm, dat, N, oC, s, mV, mA

Newtons/millimeter [N/mm]

(nmmdat) µm, kg, µN, oC, s, V, mA

microNewtons/micrometer [µN/µm]

(µmks) ft, lbm, lbf, oF, s, V, A

pound force/foot [lbf/ft]

(Bft) in, lbm, lbf, oF, s, V, A

1120

pound force/inch [lbf/in]

Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

Solving Units Unit System

Measured in . . .

(Bin) mm, mg, ms [ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

Newtons/meter [N/m] or milliNewtons/millimeter [mN/mm]

Newtons/meter [N/m]

[ LS-DYNA solver] mm, t, s

Newtons/millimeter [N/m]

[ LS-DYNA solver] in,lbf, s

pound force/inch [lbf/in]

[ LS-DYNA solver] Table 79: Strain and RS Strain Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

meter/meter [m/m]

(mks) cm, g, dyne, oC, s, V, A

centimeter/centimeter [cm/cm]

(cgs) mm, kg, N, oC, s, mV, mA

millimeter/millimeter [mm/mm]

(nmm) mm, t, N, oC, s, mV, mA

millimeter/millimeter [mm/mm]

(nmmton) mm, dat, N, oC, s, mV, mA

millimeter/millimeter [mm/mm]

(nmmdat) µm, kg, µN, oC, s, V, mA

micrometer/micrometer [µm/µm]

(µmks) ft, lbm, lbf, oF, s, V, A

feet/foot [ft/ft]

(Bft) in, lbm, lbf, oF, s, V, A

inch/inch [in/in]

(Bin) mm, mg, ms

millimeter/millimeter [mm/mm]

[ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

meter/meter [m/m]

[ LS-DYNA solver] Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

1121

Understanding Solving Unit System

Measured in . . .

mm, t, s

millimeter/millimeter [mm/mm]

[ LS-DYNA solver] in,lbf, s

inch/inch [in/in]

[ LS-DYNA solver] Table 80: Strength Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Pascals [Pa]

(mks) cm, g, dyne, oC, s, V, A

dynes/centimeter2 [dyne/cm2]

(cgs) mm, kg, N, oC, s, mV, mA

ton/second2 * millimeters [t/s2 * mm]

(nmm) mm, t, N, oC, s, mV, mA

ton/second2 * millimeters [t/s2 * mm]

(nmmton) mm, dat, N, oC, s, mV, mA

ton/second2 * millimeters [t/s2 * mm]

(nmmdat) µm, kg, µN, oC, s, V, mA

megaPascals [MPa]

(µmks) ft, lbm, lbf, oF, s, V, A

(slug/1)/second2 * foot [(lbm/32.2)1/s2 * ft]

(Bft) in, lbm, lbf, oF, s, V, A

(slinch/1)/second2 * inch [(lbm/386.4)1/s2 * in]

(Bin) mm, mg, ms

kiloPascals [kPa]

[ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

Pascals [Pa]

[ LS-DYNA solver] mm, t, s

megaPascals [MPa]

[ LS-DYNA solver]

1122

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Solving Units Unit System

Measured in . . .

in,lbf, s

pounds/inch2 [lb/in2]

[ LS-DYNA solver] Table 81: Stress and RS Stress Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Pascals [Pa]

(mks) cm, g, dyne, oC, s, V, A

dynes/centimeter2 [dyne/cm2]

(cgs) mm, kg, N, oC, s, mV, mA

ton/second2 * millimeters [t/s2 * mm]

(nmm) mm, t, N, oC, s, mV, mA

ton/second2 * millimeters [t/s2 * mm]

(nmmton) mm, dat, N, oC, s, mV, mA

ton/second2 * millimeters [t/s2 * mm]

(nmmdat) µm, kg, µN, oC, s, V, mA

megaPascals [MPa]

(µmks) ft, lbm, lbf, oF, s, V, A

slug/second2 * foot [(lbm/32.2)/s2 * ft]

(Bft) in, lbm, lbf, oF, s, V, A

slinch/second2 * inch [(lbm/386.4)/s2 * in]

(Bin) mm, mg, ms

kiloPascals [kPa]

[ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

Pascals [Pa]

[ LS-DYNA solver] mm, t, s

megaPascals [MPa]

[ LS-DYNA solver] pounds/inch2 [lb/in2]

in,lbf, s [ LS-DYNA solver] Table 82: Stress Intensity Factor Unit System o

m, kg, N, C, s, V, A

Measured in . . . Pascal * meter0.5 [Pa * m0.5] Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

1123

Understanding Solving Unit System

Measured in . . .

(mks) cm, g, dyne, oC, s, V, A (cgs) mm, kg, N, oC, s, mV, mA (nmm) mm, t, N, oC, s, mV, mA (nmmton) mm, dat, N, oC, s, mV, mA (nmmdat) µm, kg, µN, oC, s, V, mA

dyne * centimeter–2 * centimeter0.5 [dyne * cm–2* cm0.5] ton * millimeter–1 * second–2 * millimeter0.5 [ton * mm–1 * s–2 * mm0.5] ton * millimeter–1 * second–2 * millimeter0.5 [ton * mm–1 * s–2 * mm0.5] ton * millimeter–1 * second–2 * millimeter0.5 [ton * mm–1 * s–2 * mm0.5] megaPascal * micrometer0.5 [MPa * µm0.5]

(µmks) ft, lbm, lbf, oF, s, V, A

lbm_ft * feet–1 * second–2 * feet0.5 [lbm_ft * ft–1 * s–2 * ft0.5]

(Bft) in, lbm, lbf, oF, s, V, A

lbm_inch * inch–1 * second–2 * inch0.5 [lbm_in * in–1 * s–2 * in0.5]

(Bin) Table 83: Thermal Capacitance Unit System

Measured in . . .

o

Joules/degree Celsius [J/oC]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

ergs/degree Celsius [erg/oC]

(cgs) mm, kg, N, oC, s, mV, mA

milliJoules/degree Celsius [mJ/oC]

(nmm) mm, t, N, oC, s, mV, mA

milliJoules/degree Celsius [mJ/oC]

(nmmton) mm, dat, N, oC, s, mV, mA

milliJoules/degree Celsius [mJ/oC]

(nmmdat) µm, kg, µN, oC, s, V, mA

picoJoules/degree Celsius [pJ/oC]

(µmks) ft, lbm, lbf, oF, s, V, A

BTU/degree Fahrenheit [BTU/oF]

(Bft)

1124

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Solving Units Unit System

Measured in . . .

o

BTU/degree Fahrenheit [BTU/oF]

in, lbm, lbf, F, s, V, A (Bin)

Table 84: Thermal Conductance — 3D Face and 2D Edge Unit System

Measured in . . .

o

Watts/meter2 * degree Celsius [W/m2 * oC]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A (cgs) mm, kg, N, oC, s, mV, mA (nmm) mm, t, N, oC, s, mV, mA (nmmton) mm, dat, N, oC, s, mV, mA (nmmdat) µm, kg, µN, oC, s, V, mA (µmks) ft, lbm, lbf, oF, s, V, A

Watts/centimeter2 * degree Celsius [W/cm2 * oC] Watts/millimeter2 * degree Celsius [W/mm2 * oC] Watts/millimeter2 * degree Celsius [W/mm2 * oC] Watts/millimeter2 * degree Celsius [W/mm2 * oC] picoWatts/micrometer2 * degree Celsius [p/µm2 * oC] BTU/second foot2 * degree Fahrenheit [BTU/s * ft2 * oF]

(Bft) in, lbm, lbf, oF, s, V, A

BTU/second * inch2 * Fahrenheit [BTU/s * in2 * oF]

(Bin) Table 85: Thermal Conductance — 3D Edges and Vertices Unit System

Measured in . . .

o

Watts/degree Celsius [W/oC]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

Watts/degree Celsius [W/oC]

(cgs) mm, kg, N, oC, s, mV, mA

Watts/degree Celsius [W/oC]

(nmm) mm, t, N, oC, s, mV, mA

Watts/degree Celsius [W/oC]

(nmmton) mm, dat, N, oC, s, mV, mA

Watts/degree Celsius [W/oC]

Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

1125

Understanding Solving Unit System

Measured in . . .

(nmmdat) µm, kg, µN, oC, s, V, mA

picoWatts/degree Celsius [pW/oC]

(µmks) ft, lbm, lbf, oF, s, V, A

BTU/second * degree Fahrenheit [BTU/s * o F]

(Bft) in, lbm, lbf, oF, s, V, A

BTU/second * degree Fahrenheit [BTU/s * o F]

(Bin) Table 86: Thermal Expansion Unit System

Measured in . . .

o

1/degree Celsius [1/oC]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

1/degree Celsius [1/oC]

(cgs) mm, kg, N, oC, s, mV, mA

1/degree Celsius [1/oC]

(nmm) mm, t, N, oC, s, mV, mA

1/degree Celsius [1/oC]

(nmmton) mm, dat, N, oC, s, mV, mA

1/degree Celsius [1/oC]

(nmmdat) µm, kg, µN, oC, s, V, mA

1/degree Celsius [1/oC]

(µmks) ft, lbm, lbf, oF, s, V, A

1/degree Fahrenheit [1/oF]

(Bft) in, lbm, lbf, oF, s, V, A

1/degree Fahrenheit [1/oF]

(Bin) microJoules/degree Kelvin [µJ/oK]

mm, mg, ms [ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

1/degree Kelvin [1/oK]

[ LS-DYNA solver] mm, t, s

1/degree Kelvin [1/oK]

[ LS-DYNA solver]

1126

Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

Solving Units Unit System

Measured in . . .

in,lbf, s

1/degree Fahrenheit [1/oF]

[ LS-DYNA solver] Table 87: Temperature Unit System

Measured in . . .

o

degrees Celsius [oC]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

degrees Celsius [oC]

(cgs) mm, kg, N, oC, s, mV, mA

degrees Celsius [oC]

(nmm) mm, t, N, oC, s, mV, mA

degrees Celsius [oC]

(nmmton) mm, dat, N, oC, s, mV, mA

degrees Celsius [oC]

(nmmdat) µm, kg, µN, oC, s, V, mA

degrees Celsius [oC]

(µmks) ft, lbm, lbf, oF, s, V, A

degrees Fahrenheit [oF]

(Bft) in, lbm, lbf, oF, s, V, A

degrees Fahrenheit [oF]

(Bin) degrees Kelvin [oK]

mm, mg, ms [ANSYS (AUTODYN) and LS-DYNA solvers]

degrees Kelvin [oK]

m, kg, s [ LS-DYNA solver]

degrees Kelvin [oK]

mm, t, s [ LS-DYNA solver]

degrees Fahrenheit [oF]

in,lbf, s [ LS-DYNA solver] Table 88: Temperature Difference Unit System o

m, kg, N, C, s, V, A

Measured in . . . degrees Celsius [oC] Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

1127

Understanding Solving Unit System

Measured in . . .

(mks) cm, g, dyne, oC, s, V, A

degrees Celsius [oC]

(cgs) mm, kg, N, oC, s, mV, mA

degrees Celsius [oC]

(nmm) mm, t, N, oC, s, mV, mA

degrees Celsius [oC]

(nmmton) mm, dat, N, oC, s, mV, mA

degrees Celsius [oC]

(nmmdat) µm, kg, µN, oC, s, V, mA

degrees Celsius [oC]

(µmks) ft, lbm, lbf, oF, s, V, A

degrees Fahrenheit [oF]

(Bft) in, lbm, lbf, oF, s, V, A

degrees Fahrenheit [oF]

(Bin) degrees Kelvin [oK]

mm, mg, ms [ANSYS (AUTODYN) and LS-DYNA solvers] Table 89: Temperature Gradient Unit System

Measured in . . .

o

degrees Celsius/meter [oC/m]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

degrees Celsius/centimeter [oC/cm]

(cgs) mm, kg, N, oC, s, mV, mA

degrees Celsius/millimeter [oC/mm]

(nmm) mm, t, N, oC, s, mV, mA

degrees Celsius/millimeter [oC/mm]

(nmmton) mm, dat, N, oC, s, mV, mA

degrees Celsius/millimeter [oC/mm]

(nmmdat) µm, kg, µN, oC, s, V, mA

degrees Celsius/micrometer [oC/µm]

(µmks)

1128

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Solving Units Unit System

Measured in . . .

o

degrees Fahrenheit/foot [oF/ft]

ft, lbm, lbf, F, s, V, A (Bft) in, lbm, lbf, oF, s, V, A

degrees Fahrenheit/inch [oF/in]

(Bin) degrees Kelvin/millimeter [oK/mm]

mm, mg, ms [ANSYS (AUTODYN) and LS-DYNA solvers] Table 90: Time Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

seconds [s]

(mks) cm, g, dyne, oC, s, V, A

seconds [s]

(cgs) mm, kg, N, oC, s, mV, mA

seconds [s]

(nmm) mm, t, N, oC, s, mV, mA

seconds [s]

(nmmton) mm, dat, N, oC, s, mV, mA

seconds [s]

(nmmdat) µm, kg, µN, oC, s, V, mA

seconds [s]

(µmks) ft, lbm, lbf, oF, s, V, A

seconds [s]

(Bft) in, lbm, lbf, oF, s, V, A

seconds [s]

(Bin) mm, mg, ms

milliseconds [ms]

[ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

seconds [s]

[ LS-DYNA solver] mm, t, s

seconds [s]

[ LS-DYNA solver]

Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

1129

Understanding Solving Unit System

Measured in . . .

in,lbf, s

seconds [s]

[ LS-DYNA solver] Table 91: Translational Damping Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Newton * seconds/meter [N * s/m]

(mks) cm, g, dyne, oC, s, V, A

dyne * seconds/centimeter [dyne * s/cm]

(cgs) mm, kg, N, oC, s, mV, mA (nmm) mm, t, N, oC, s, mV, mA (nmmton) mm, dat, N, oC, s, mV, mA (nmmdat) µm, kg, µN, oC, s, V, mA (µmks) ft, lbm, lbf, oF, s, V, A

ton * millimeter * seconds/second2 * millimeter [t * mm * s/s2 * mm] ton * millimeter * seconds/second2 * millimeter [t * mm * s/s2 * mm] ton * millimeter * seconds/second2 * millimeter [t * mm * s/s2 * mm] microNewton * seconds/micrometer [µN * s/µm] slugfoot * seconds/second2 * foot [(lbm/32.2)ft * s/s2 * ft]

(Bft) in, lbm, lbf, oF, s, V, A

slinchinch * seconds/second2 * inch [(lbm/386.4)in * s/s2 * in]

(Bin) Table 92: Velocity and RS Velocity Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

meters/second [m/s]

(mks) cm, g, dyne, oC, s, V, A

centimeters/second [cm/s]

(cgs) mm, kg, N, oC, s, mV, mA

millimeters/second [mm/s]

(nmm) mm, t, N, oC, s, mV, mA

millimeters/second [mm/s]

(nmmton) mm, dat, N, oC, s, mV, mA

1130

millimeters/second [mm/s]

Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

Solving Units Unit System

Measured in . . .

(nmmdat) µm, kg, µN, oC, s, V, mA

micrometers/second [µm/s]

(µmks) ft, lbm, lbf, oF, s, V, A

feet/second [ft/s]

(Bft) in, lbm, lbf, oF, s, V, A

inches/second [in/s]

(Bin) mm, mg, ms [ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

meters/second [m/s] or millimeters/millisecond [mm/ms]

meters/second [m/s]

[ LS-DYNA solver] mm, t, s

millimeters/second [mm/s]

[ LS-DYNA solver] in,lbf, s

inches/second [in/s]

[ LS-DYNA solver] Table 93: Voltage Unit System

Measured in . . .

o

m, kg, N, C, s, V, A

Volts [V]

(mks) cm, g, dyne, oC, s, V, A

Volts [V]

(cgs) mm, kg, N, oC, s, mV, mA

milliVolts [mV]

(nmm) mm, t, N, oC, s, mV, mA

milliVolts [mV]

(nmmton) mm, dat, N, oC, s, mV, mA

milliVolts [mV]

(nmmdat) µm, kg, µN, oC, s, V, mA

Volts [V]

(µmks) ft, lbm, lbf, oF, s, V, A

Volts [V]

(Bft)

Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

1131

Understanding Solving Unit System

Measured in . . .

o

in, lbm, lbf, F, s, V, A

Volts [V]

(Bin) Table 94: Volume Unit System

Measured in . . .

o

meters3 [m3]

m, kg, N, C, s, V, A (mks) cm, g, dyne, oC, s, V, A

centimeters3 [cm3]

(cgs) mm, kg, N, oC, s, mV, mA

millimeters3 [mm3]

(nmm) mm, t, N, oC, s, mV, mA

millimeters3 [mm3]

(nmmton) mm, dat, N, oC, s, mV, mA

millimeters3 [mm3]

(nmmdat) µm, kg, µN, oC, s, V, mA

micrometers3 [µm3]

(µmks) ft, lbm, lbf, oF, s, V, A

feet3 [ft3]

(Bft) in, lbm, lbf, oF, s, V, A

inches3 [in3]

(Bin) millimeters3 [mm3]

mm, mg, ms [ANSYS (AUTODYN) and LS-DYNA solvers] m, kg, s

meters3 [m3]

[ LS-DYNA solver] mm, t, s

millimeters3 [mm3]

[ LS-DYNA solver] in,lbf, s

inches3 [in3]

[ LS-DYNA solver]

Saving your Results in the Mechanical Application There are three ways to save your results in the Mechanical application:

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Writing and Reading the Mechanical APDL Application Files • As a Mechanical APDL application database file. To save the Mechanical application results in a Mechanical APDL application database file, click Analysis Settings on the Tree Outline (p. 3) and in its Details, click Yes next to Save ANSYS db under Analysis Data Management (p. 664). • As an input file for the Mechanical APDL application. See Writing and Reading the Mechanical APDL Application Files (p. 1133). • As a Mechanical application database file. To save your solution as a Mechanical application database file, select File> Export. Select File> Save As in the Project Schematic to save the project. The Save As dialog box appears, allowing you to type the name of the file and specify its location.

Note The application creates reference files that contain analysis information that is read back into the application during solution processing. Certain textual characters can create issues during this reading process. Avoid the use of the following characters in your file naming conventions: • Quote character (“) • Ampersand (&) • Apostrophe (‘) • Greater than and less than characters (< >)

Writing and Reading the Mechanical APDL Application Files The Tools menu includes options for writing the Mechanical APDL application input files and for reading the Mechanical APDL application results files. To write the Mechanical APDL application input file: 1. Highlight the Solution object folder in the tree. 2. From the Main Menus (p. 44), choose Tools> Write Input File. 3. In the Save As dialog box, specify a location and name for the input file. To read the Mechanical APDL application result files: 1. Highlight the Solution object folder in the tree. 2. From the Main Menus (p. 44), choose Tools> Read Result Files. 3. Browse to the folder that contains the Mechanical APDL application result files and click Open. 4. In the dialog box that follows, select the unit system, then click OK.

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Understanding Solving

The Unit System used during the solution is stored in the results file (/UNITS command). The Select Results in Unit System dialog box displays to have you verify the system. Selecting a unit system that differs from the specified result file unit system causes a warning message to display. If the application does not have a specified unit system (/UNITS,0), then the application warns you that you have updated the system based on your choice in the Select Results in Unit System dialog box.

Caution • Errors will occur if the Mechanical APDL application result files are from a version of the Mechanical application that is older than the version currently running. • The procedure above instructs you to browse to the folder that contains the Mechanical APDL application result files. This folder should only contain files pertinent to that solution because Mechanical copies all the files contained in this folder to the Solver Files Directory. In addition, for the file names that match the jobname you select in the file browse window the application renames them to the “file” jobname during the copy.

Mechanical APDL Application Analysis from a Mechanical Application Mesh The option for writing the Mechanical APDL application file can be used to perform analyses in the Mechanical APDL application while taking advantage of the meshing capabilities within the Mechanical application. The procedure is as follows: 1. Attach the model into the Mechanical application. 2. Mesh the model. 3. Select the Solution folder in the tree. 4. Tools> Write Input File… and specify a location and name for the input file.

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Converting Boundary Conditions to Nodal DOF Constraints (Mechanical APDL Solver) 5. Use this input file to complete your analysis in the Mechanical APDL application. The meshed model will contain generic elements encoding only shape and connectivity information. Such elements can then be replaced by others that are appropriate to your desired analysis.

Note Any named selection group from the Mechanical application is transferred to the Mechanical APDL application as a component according to specific naming rules and conventions.

Using Writing and Reading Files Together The writing and reading options are useful when used together. You can use the write option, then solve at your leisure on the machine of your choice. When the solution is done, you can use the read option to browse to the directory that contains the Mechanical APDL application output files (for example, result file, file.err, solve.out, file.gst, file.nlh). Workbench will then copy all files into your solution directory and proceed to use those files for postprocessing. The reading option requires that the directory include the result and file.err files at a minimum.

Note You must ensure that the mesh in the result file matches the mesh in Workbench. This includes the Workbench generated mesh from the geometry as well as any nodes or elements defined in the input file (such as for contact or remote boundary conditions). Failure to do so could result in incorrect results and unexpected behavior. The reading Mechanical APDL application file option is available for all analysis types except rigid dynamic analyses and shape analyses. The writing Mechanical APDL application file option is available for all analysis types except rigid dynamic analyses. System units must be specified in the Mechanical APDL application result files being read for Result Tracker graphs to display properly. Result Tracker graphs will display in the Mechanical APDL application result file units if the units specified when reading the files are inconsistent with those in the files.

Converting Boundary Conditions to Nodal DOF Constraints (Mechanical APDL Solver) This section discusses converting structural boundary conditions on the geometry to constraints on the mesh for analyses targeting the ANSYS solver. In the Mechanical APDL application, structural degree-of-freedom constraints can be defined at individual nodes. Specifically, you can choose to constrain each node along any of the three axis directions (x, y, z) of its local coordinate system to simulate the kinds of supports your model requires. In the Mechanical application, however, you specify boundary conditions on the geometry, so the program must automatically convert them into nodal constraints prior to solution. Ordinarily, this process is straightforward and the boundary conditions can be transcribed directly onto the nodes. In certain cases, however, the Mechanical application may be confronted with combinations of boundary conditions that require negotiation to produce an equivalent rendition of the effective constraints acting on the nodes. A common case occurs in structural analyses where two or more boundary conditions are applied to neighboring topologies, for example, Frictionless Supports applied to neighboring faces that meet Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Understanding Solving at an angle: the nodes on the edge are subject to two separate combinations of DOF constraints, one from each Frictionless Support. The Mechanical application attempts to identify a suitable orientation to the nodal coordinate system that accommodates both frictionless supports and, if successful, constrain its axes accordingly. Should this attempt ever fail, the solution will be prevented and an error will be issued to the Message Window (See The Solver Has Found Conflicting DOF Constraints (p. 1432) in the Troubleshooting section.) Among the boundary conditions that participate in this conversion, there are: Fixed Supports (Fixed Face, Fixed Edge, Fixed Vertex) Simply Supported (Edge or Vertex) Fixed Rotation Displacements (Displacements for Faces, Displacement for Edges, Displacements For Vertices) Frictionless Support Cylindrical Support Symmetry Regions The calculations that convert the boundary conditions into nodal constraints involve: • the identification of the linear span contributed by each of the boundary conditions • the combination of the individual spans into a final nodal constraint choice. Angular tolerances are involved in distinguishing and combining the spans; a program controlled tolerance of 0.01 degrees will be used.

Note The calculations have a built in preference for producing nodal coordinate systems that are closest in orientation to the global coordinate system.

Resolving Thermal Boundary Condition Conflicts Conflicts between boundary conditions scoped to parts and individual faces Boundary conditions applied to individual geometry faces always override those that are scoped to a part(s). For conflicts associated with various boundary conditions, the order of precedence is as follows: 1. Applied temperatures (Highest). 2. Convection, heat fluxes, and flows (Cumulative, but overridden by applied temperatures). 3. Insulated (Lowest. Overridden by all of the above).

Resume Capability for Explicit Dynamics Analyses If an Explicit Dynamics analysis has partially or totally completed, then it is possible to resume the analysis from a non-zero time step (cycle). These are some examples of why this would be desirable: • To extend an analysis that has successfully completed beyond its current end time or cycle. • To complete an analysis that has been interrupted. For example you may wish to interrupt an analysis in order to review results part way through a longer simulation.

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Solving a Fracture Analysis • To continue an analysis that has stopped part way through. For example, if an analysis has terminated prematurely due to the time-step size being too small, you can make adjustments to mass scaling, and restart the calculation. • To adjust the frequency of restart file, result file or other output information. For example, you may wish to re-solve part of an analysis that is of interest with more frequent results. • To adjust damping or erosion controls. An analysis may be resumed from any cycle that has a restart file by first selecting the cycle in the Resume From Cycle field located in the Step Controls section of the Analysis Settings, then making any other required analysis changes, and selecting Solve. The frequency of restart file output is controlled in the Analysis Settings Output Controls. There is no limit to the number of times an analysis may be resumed. The following restrictions apply: • Changes made to any feature of the model outside of the Analysis Settings will prevent a resume from taking place. • Changes made to any of the (Analysis Settings) Solver Controls, except for Minimum Velocity, Maximum Velocity and Radius Cutoff, will prevent a resume from taking place. • Changes made to the Retain Inertia of Eroded Material field will prevent a resume from taking place. • Changes to all other Erosion Controls, Damping Controls, and Output Controls are valid and will not prevent a resume from taking place. • To use Automatic Mass Scaling under (Analysis Settings, Step Controls), it must be enabled from the start of the calculation. You cannot change the Automatic Mass Scaling property for a restart calculation. If Automatic Mass Scaling is active, the other Mass Scaling properties may be changed part way through a calculation. • Analyses with non-zero Displacement constraints defined may not be resumed.

Solving a Fracture Analysis Once the crack mesh is generated, you can apply loads and constraints, then solve the analysis. Then, once the solution is done, you can analyze the stress and deformation pattern around the crack. For meshes defined by the Crack object, you can apply the loads on the crack face top and bottom discontinuity plane using nodal named selections. For the Crack object, the internally generated crack mesh is defined after the initial base mesh is generated. The base mesh generation is based on a different set of requirements and constraints than the crack mesh. As a result, the crack mesh may not match perfectly the boundaries of the fracture affected zone. Because they may not match perfectly, kinematic constraints are required to establish a connection between base mesh and crack mesh in the boundaries of the fracture affected zone, which is accomplished using the multi-point constraint (MPC) contact. A contact pair is created at the interface of the

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Understanding Solving crack and base meshes. When the solution is performed using internally-generated crack meshes, the MPC contact region is automatically created and sent to the solver.

Note The static structural analysis is the only analysis applicable to performing fracture mechanics calculations. However, the mesh with cracks is also supported with a static structural analysis linked to an upstream steady state thermal or transient thermal analysis. Also, all loads and boundary conditions applicable to the static structural analysis are applicable with the existence of crack in the solution.

Computation of Fracture Parameters The stress and deformation pattern around the crack is not sufficient to evaluate the catastrophic failure of the structure. The computation of fracture parameters and its comparison against fracture toughness is necessary for designing safe structures. To compute fracture parameters for all cracks defined under the Fracture folder, the “Fracture” setting under the Solver Controls of the Analysis Settings must be turned “On”. This new entry is visible It is visible only if the Fracture folder exists in the model. For more information, see Fracture (p. 643). The computations used for fracture analysis include Stress Intensity Factors (SIFS), J-Integral (JINT), and Energy Release Rates. The Mode 1 Stress Intensity Factor (K1), Mode 2 Stress Intensity Factor (K2), and Mode3 Stress Intensity Factor (K3) are computed along the crack front using the interaction integral method. The Mode 1 Energy Release Rate (G1) and Mode 2 Energy Release Rate (G2), Mode 3 Energy Release Rate (G3) and Total Energy Release Rate (GT) are computed using the Virtual Crack Closure Technique (VCCT) along the crack front.

Note The Energy Release Rate parameters, which are specific to the Pre-Meshed Crack object, are computed using the Virtual Crack Closure Technique (VCCT). When the VCCT technique is used, a specific mesh pattern comprised of hexahedral shapes along the crack front is recommended for better accuracy. For more information, see Fracture Mechanics in the Structural Analysis Guide. The JINT result is a mixed mode result and is also computed along the crack front using the domain integral method. The fracture parameters, for all cracks defined under the fracture folder, are automatically computed and stored in the results file when the “Fracture” setting under the “Solver Controls” of Analysis Settings is turned on. The SIFS and JINT results are calculated for all cracks defined under the Fracture folder. The VCCT results are calculated only if the crack mesh generated is of lower order (dropped midside nodes). You can direct the fracture parameter computation for all cracks to use symmetry by setting the all cracks symmetric variable to active with a value of 1 in the Variable Manager. For more information, see Setting Variables (p. 85). Fracture parameter calculation based on SIFS supports linear isotropic elastic material behavior. J-Integral based fracture parameter calculation supports isotropic elastic and isotropic plastic material behavior. VCCT based fracture parameter calculation supports linear isotropic elastic, anisotropic elastic and orthotrophic elastic material behavior.

Note If you get the following message:

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Solving a Fracture Analysis The fracture parameters computed during solution may be incorrect. Check the Solver Output on the Solution Information object for possible causes. Check for the following: • A contact might have been created in the region of the crack contours. • A load might have been applied in the region of the crack contours that is not supported in the fracture parameter computation. Try replacing it with a Direct FE load.

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Commands Objects You can input commands such as Mechanical APDL commands, directly in the Mechanical application using a Commands object. Refer to the Commands objects reference page for information on valid objects under which you can insert single or multiple Commands objects. Upon inserting a Commands object, the Worksheet appears and displays information or special instructions tailored to the specific parent object. For example, the following information appears if you insert a Commands object under a Contact Region object: *********contact region default statement********* ! Commands inserted into this file will be executed just after the contact region definition. ! The type number for the contact type is equal to the parameter «cid». ! The type number for the target type is equal to the parameter «tid». ! The real and mat number for the asymmetric contact pair is equal to the parameter «cid». ! The real and mat number for the symmetric contact pair(if it exists) is equal to the parameter «tid».

Note For the Transient Structural (Rigid Dynamics) systems, commands are expressed in Python. The following topics are covered in this section: Commands Object Features Using Commands Objects with the MAPDL Solver Using Commands Objects with the Rigid Dynamics Solver

Commands Object Features Solver Target The Target property in the Details view of a Commands object allows you to associate the object with a solver target. All text that displays for a new Commands object can vary and is dependent on the associated solver target. When displayed, the Target property is set according to the following situations: • If all the environments in the tree have the same solver target then the Commands object is tied to that solver target. • If there is a mix of solver targets in the tree, the Target property is left empty and you must assign a solver target. The commands inserted into the Commands object will only be sent to the solver if the solver target of the environment being solved matches that of the Commands object.

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Commands Objects

Post Processing Command Specifications The Commands object can perform post processing actions when inserted under the Solution object. For solved analyses, you can specify a command and choose whether the MAPDL Solver processes the specified commands only or whether the solver processes the entire solution (including the new command) all over again using the Invalidate Solution control. This control is, by default, set to No — do not invalidate the results. If the solver is not specified as MAPDL, then the Invalidate Solution control defaults to Yes and is read-only. An example of the Commands object and its Details is illustrated below.

As shown on the status/progress dialog box, the Solver processes only the newly specified commands.

Post Output File The post command entries generate a new and independent solution output file, post.dat. The post.dat file contains only the content of unsuppressed command objects. The output file can be viewed in the Worksheet for the Solution Information object by setting the Solution Output control to Post Output, as shown below.

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Commands Object Features

Note • This post processing solution only happens if changes or additions are made to the Commands of a Solution object for an otherwise solved environment. If the solution is unsolved or obsolete for some other reason, then the commands are executed as part of the normal solving process. • Existing and post processed results are available for use with any subsequent linked analyses. • When using this mode, MAPDL runs all commands including the ones that may have existed as a part of the regular solve. Some commands may require certain variables or parameters to be active for execution or to produce correct results. As a result, it may be necessary to resume MAPDL db file by making sure that the Analysis Settings>Analysis Data Management>Save MAPDL db option is set to Yes prior to restarting the entire solution. • The solve mode is always In Process. • If the command snippet is inserted or edited with the Invalidate Solution setting set to Yes, then you can issue post-processing commands using the last restart point of a completed solution. The solution executes without incurring the cost of a full solve, as it sends only the post commands and will generate solve.out as a solution output file.

Note that the generated Output files are written to the Solver Files Directory and are named accordingly. An example of the directory is shown below.

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Commands Objects

Input Arguments (Not applicable to the LS-DYNA solver) Input arguments are available on all Commands objects. There are nine arguments that you can pass to the Mechanical APDL application macros. Numerical values only are supported. Input Arguments are editable on the Details view of a Commands object under Input Arguments and listed as ARG1 through ARG9. If you enter a numerical value, including zero, for an argument, that value is passed along to the Mechanical APDL application. If you leave the argument value field empty, no argument value is passed for that specific argument.

Note If you are calling a user defined macro from within a Commands object, be aware of the macro’s location on the disk to make sure the macro is able to be located during the solution. Refer to the /PSEARCH command description located in the Mechanical APDL application Command Reference within the Mechanical APDL Help for more information.

Commands Object Controls The following controls are also available with Commands objects. Each control is available from the toolbar or from the context menu that appears from a right mouse button click on a Commands object: • Export…: Exports the text in the Worksheet to an ASCII text file.

Note You must right-mouse click on the selected object in the tree to use this Export feature. On Windows platforms, if you have the Microsoft Office 2002 (or later) installed, you may see an Export to Excel option if you right-mouse click in the Worksheet. This is not the Mechanical application Export feature but rather an option generated by Microsoft Internet Explorer.

• Import…: Imports the text from an ASCII text file to the Worksheet.

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Using Commands Objects with the MAPDL Solver You can rename the Commands object to the name of an imported or exported file by choosing Rename Based on Definition from the context menu available through a right mouse button click. The Commands object is renamed to the name appearing in the File Name field under the Details view. • Refresh: Synchronizes the text in the Worksheet to that of the currently used ASCII text file. Refresh can be used to discard changes made to commands text and revert to a previously imported or exported version. • Suppress (available in context menu only): Suppressed commands will not propagate to the Mechanical APDL application input file.

Note Preprocessing Commands objects or Postprocessing Commands objects, available in past releases are no longer supported. If you open a database that includes these objects, the objects are automatically converted to Commands objects.

• Search Parameters (available only at the Solution level): Scans the text output and updates the list of detected parameters. Matched the Mechanical APDL application parameters can be parameterized just as other values in Workbench can be parameterized. Refer to the next section for details.

Using Commands Objects with the MAPDL Solver The following information applies to Command objects used with the MAPDL solver. Their use with other solvers may exhibit different behavior.

Text and Units Commands text cannot contain characters outside of the standard US ASCII character set due to the fact that this text will propagate into the Mechanical APDL application input files and must follow the rules set aside for the Mechanical APDL application commands and input files. Use of languages other than English for the command text may cause erratic behavior. The Mechanical APDL application commands should not be translated. Make sure that you use consistent units throughout a simulation. Commands objects whose inputs are units-dependent will not update if you change unit systems for solving. Commands object input for magnetostatic analyses must be in MKS units (m, Kg, N, V, A).

Step Selection Mode For stepped analyses, the Step Selection Mode control is also available in the Details view of a Commands object when you insert the object under an Environment. This control allows you to specify which sequence steps are to process the Commands object. The choices are: First, Last, All, and By Number. If you choose By Number, a Sequence Number control appears that allows you to scroll through and select a specific numbered step that will process the Commands object.

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Commands Objects

User Convenience Parameters When a project is saved in workbench, the application’s project file management creates a directory/folder structure. The generated folders house a variety of files, such as input or result files. As a part of this structure, there is a folder created that is named user_files. The MAPDL solver input file, ds.dat, includes the following parameter (variable): _wb_userfiles_dir(1) The value of this parameter equals the path to the user_files directory. You can use this parameter with the Commands Object and perform file operations in the MAPDL language. For example, by specifying this parameter, you can copy result files to the user_files directory. For a more specific example, accessing external user macros located in this directory might be done using the following MAPDL command: /INPUT, ‘%_wb_userfiles_dir(1)%file_aqld1001.dat’

For additional information on the MAPDL Command language, see the Mechanical APDL Command Reference.

Output Parameters: Using Parameters Defined in Solution Command Objects For Commands objects at the Solution level, an output search prefix can be used to scan the text from a resulting solution run. After you choose Search Parameters, values for the Mechanical APDL application parameter assignments are returned that match the output search prefix. The default output search prefix is my_. Changing the prefix at any time causes a rescan of the text for a matching list. After a SOLVE, the Mechanical APDL application parameters that are found to match the prefix are listed in the Details view for the Commands object with their values. This procedure is illustrated in the demonstration below. Parameters created using Commands objects can be used in Design Exploration.

Note If you have parameterized an output parameter in the Commands object, you cannot edit the command text. You need to remove the parameters to edit the text The following demo is presented as an animated GIF. Please view online if you are reading the PDF version of the help. Interface names and other components shown in the demo may differ from those in the released product.

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Using Commands Objects with the MAPDL Solver

Viewing Mechanical APDL Application Plots in Workbench You can view Mechanical APDL application plots in Workbench that result from using Commands objects. The Mechanical APDL application plots are returned from Mechanical APDL to display in the Worksheet. This feature is useful if you want to review result plots that are available in the Mechanical APDL application but not in Workbench, such as unaveraged stress results or contact results only on a particular region. To View the Mechanical APDL Application Plots in Workbench: 1.

Create one or more Commands objects.

2.

Direct plot(s) to PNG format.

3.

Request plots in the Commands objects.

4.

Make sure that there is at least one Commands object under Solution in the tree.

5.

Solve. Requested plots for all Commands objects are displayed as objects under the first unsuppressed Commands object that appears below Solution.

Note The Mechanical APDL application PowerGraphics mode for displaying results is not compatible with Commands objects. No results will be produced in this mode. If your command list includes the PowerGraphics mode (/GRAPH,POWER), you must switch to the Full mode by including /GRAPH,FULL at the end of the list. Presented below is an example of a Commands object used to create two plots, one for unaveraged stress, and one for element error. ! Commands inserted into this file will be executed immediately after the ANSYS /POST1 command. ! If a SET command is issued, results from that load step will be used as the basis of all ! result objects appearing in the Solution folder. /show,png ! output to png format /gfile,650

! adjust size of file

/edge,1,1 /view,,1,1,1

! turn on element outlines ! adjust view angle

ples,s,eqv ples,serr

! plot unaverage seqv ! plot element error

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Commands Objects The Mechanical APDL application plots are shown below. Unaveraged Stress Result:

Element Error Result:

Suggestions on Using Commands Objects with Materials 1. When using Commands objects, do not change the material IDs for elements. This will cause the results retrieval form the Mechanical APDL application to Workbench to malfunction. 2. Instead of adding one large Commands object to change all of the materials, add individual Commands objects under each part. That way you will be able to reference the “matid” in the Commands object for the material ID of the elements that make up the part. You will also only need to enter the adjusted coefficient of thermal expansion and not the other materials. 3. Use the Worksheet view of the Geometry object to determine which materials are assigned to specific parts. 4. Click the right mouse button on a selected item in the Worksheet view, then choose Go To Selected Items in Tree to add Commands objects. 5. Copy and paste Commands objects from one part to another that have the same material assignment.

Possible Conflicts Between the Mechanical and Mechanical APDL Applications Commands objects can be used to access the Mechanical APDL application commands from within Workbench. The commands issued by the Commands objects affect the solution. However they do not alter settings within Workbench. The Mechanical APDL application commands used in Commands objects may conflict with internal settings in Workbench.

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Using Commands Objects with the Rigid Dynamics Solver One example where a possible conflict between the Mechanical APDL application and Workbench can occur is when Commands objects are used to define material models. The user may have defined only linear elastic properties in Engineering Data. However, it is possible to use the Mechanical APDL application commands in a Commands object to override the material properties defined in Engineering Data or even change the linear elastic material model to a nonlinear material model, such as adding a bilinear kinematic hardening (BKIN) model. In that case, the solution will use the BKIN model defined in the Commands object. However, since the Mechanical application is unaware of the nonlinear material specified by the Commands object, nonlinear solution quantities such as plastic strain will not be available for postprocessing. Another example where a possible conflict between the Mechanical APDL application and Workbench can occur is when Commands objects are used to define boundary conditions. The Mechanical APDL application nodal boundary conditions are applied in the nodal coordinate system. For consistency, Workbench sometimes must internally rotate nodes. The boundary conditions specified by the commands in the Commands object will be applied in the rotated nodal coordinate system. Other situations can occur where the Mechanical APDL application commands issued in Commands objects are inconsistent with Workbench. It is the user’s responsibility to confirm that any the Mechanical APDL application commands issued in a Commands object do not conflict with Workbench. Commands support the definition of Mechanical APDL arguments via the settings of the properties ARG1 through ARG9. Once a value for one of these arguments is set, it will be retained for the remainder of the MAPDL solve run unless explicitly set to zero in the Commands text.

Using Commands Objects with the Rigid Dynamics Solver The following information applies to Commands Objects used with the Rigid Dynamics solver. Their use is very similar to Commands Objects used in the Mechanical APDL solver, but their behavior may differ. This section highlights these differences. The Rigid Dynamics solver commands are based on Python and follow the Python syntax. See Command Reference for Rigid Dynamics Systems (p. 226) for a complete list and descriptions of commands available with the Rigid Dynamics solver. The Rigid Dynamics solver only considers one Commands Object per level. Other Commands Objects are ignored when present.

Output Parameters: Using Parameters Defined in Solution Command Objects As with the MAPDL solver, Commands Objects at the solution level can be used to retrieve values such as output parameters. Their use is similar to MAPDL (see Using Commands Objects with the MAPDL Solver (p. 1145)) except for the following differences: • The Rigid Dynamics solver is case sensitive. • Unlike MAPDL, it is not possible to perform post-only solve. Modifications to Commands Objects at the Solution level require a full solve.

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Setting Parameters The term Parameters in the Mechanical application includes CAD parameters and engineering parameters (pressure magnitude, maximum stress, fatigue life, dimension of a part, material property type, Young’s modulus, and others). While engineering parameters are indicated simply by clicking the parameter box in the Details View (p. 11), CAD Parameters (p. 1153) must be given some extra attention, both in the CAD package and in the Mechanical application. The Parameter tab collects all specified parameters and lists them in the Parameter tab grids for later use and/or modification. Related topics: • Specifying Parameters (p. 1151)

Specifying Parameters The Details View (p. 11) in the application window provides check boxes for items that may be parameterized. The following Details View images illustrate parameter definition for typical objects in the Mechanical application: Part Object (p. 1151) Force Object (p. 1152) Stress Object (p. 1152)

Part Object The details of a part object:

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Setting Parameters

A P defines the Volume as parameterized.

Force Object The details for a Force object:

The Magnitude of the force is parameterized. Other details, such as the Geometry, Define By and Direction cannot be parameterized.

Stress Object The details for a Stress object.

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CAD Parameters

A P appears next to the selected output parameters. The Minimum is selected as an output parameter. The Maximum is not selected as an output parameter.

Parameter Restrictions If an object has a parameterized field, and that object definition is changed in a way that makes that parameterization non-meaningful, the parameterization will be removed by the program. Some examples include: • A material in Engineering Data has a parameterized density, and then the user suppresses the material. • A result in the Mechanical application is scoped to a face and has a parameterized maximum value, and then the user re-scopes the result to a different topology.

Note If you suppresses an object, no parameter boxes will be shown for any property on that object. If you parameterize the Suppressed property on an object, no parameter boxes will be shown for any other property on that object, regardless of whether or not the object is suppressed.

CAD Parameters CAD parameters are a subset of the application parameters. As the name implies, CAD parameters come from a CAD system and are used to define the geometry in the CAD system. Although each CAD system assigns its parameters differently, the Mechanical application identifies them via a key (ds or DS). This identifier can appear either at the beginning or the end of the parameter name and does not need to be separated from the name with an underscore or any other character. By identifying the parameters of interest you can effectively filter CAD parameter exposure. Any of the following examples are valid CAD parameter names using DS or ds as the key: • DSlength • widthds

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Setting Parameters • dsradius DS is the default key for importing CAD parameters into the application. You can change this default via the Personal Parameter Key option on the Geometry Preferences.

Note If you change the key phrase to nothing all parameters are exposed. CAD parameters must be assigned correctly in the CAD system in order to be imported. Refer to your CAD system instructions for detailed information on assigning these parameters. Some system specific notes are included here for your convenience. Remember that these are all actions that must be performed in the CAD system before importing the model. CAD systems: • Autodesk Inventor (p. 1154) • CATIA V5 (p. 1154) • Creo Parametric (formerly Pro/ENGINEER) (p. 1154) • NX (p. 1155) • Solid Edge (p. 1155) • SolidWorks (p. 1155)

Autodesk Inventor After a part is open in Inventor, click Tools> Parameters. In the Parameters dialog box, click a parameter name under the Parameter Name column, modify the parameter name to include ds at either the beginning or end of the name and click Enter. Click Done to close the Parameters dialog box. For detailed information, see CAD Integration.

CATIA V5 After a part is open in CATIA V5, click Tools> Formula. In the Formulas dialog box, select the desired parameter in the scrolling list. In the «Edit name or value of the current parameter» field, modify the parameter name to include ds at either the beginning or end of the name, then click OK or Apply. For detailed information, see CATIA V5 Associative Geometry Interface (*.CATPart, *.CATProduct) in the CAD Integration section of the product help.

Creo Parametric (formerly Pro/ENGINEER) In Creo Parametric, modify the parameter name by selecting the feature it belongs to, right click on Edit. Creo Parametric will then display all dimensions (parameters) for the selected feature. If the model shows numeric values, then select Info> SwitchDims so that the names are text based instead of numeric. Next, select the dimension/parameter you wish to rename, it will turn red when selected. Then hold down right click until a menu appears and there select Properties. The Dimension Properties dialog box will appear, select the Dimension Text tab. Here you can give the dimension a new name,

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CAD Parameters also be sure to change the @D to @S (case sensitive) before completing the modification by clicking OK. For detailed information, see Creo Parametric (formerly Pro/ENGINEER) Associative Geometry Interface (*.prt, *.asm) in the CAD Integration section of the product help.

NX After a model is opened in NX, click Application> Modeling and the Tools> Expression In the Edit Expressions dialog box, select the expression with the variable name that you want to rename and click Rename. Change the expression name in the Rename Variable dialog box to include ds at either the beginning or end of the name and click OK. Click OK/Apply to close the Edit Expressions dialog box. For detailed information, see NX in the CAD Integration section of the product help.

Solid Edge After a model is opened in Solid Edge, click Tools> Variables… If the dimensions (type Dim) are not shown in the Variable Table dialog box, click the Filter button for the Filter dialog box. Highlight both Dimensions and User Variables under the Type column; select Both under the Named By column and select File under the Graphics in column. Then click OK. Click the name of a dimension (under the Name column), modify the dimension name to include ds at either the beginning or end of the name and click Enter. Close the Variable Table dialog box. For detailed information, see Solid Edge in the CAD Integration section of the product help.

SolidWorks In SolidWorks, open the part and then click on the part or on the feature in the tree. Then right-click the dimension on the model, open the Properties dialog box, and edit the name of the dimension. For detailed information, see SolidWorks in the CAD Integration section of the product help.

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Using Design Assessment The Design Assessment system provides further options to quantitatively examine the results from other Mechanical application systems by supporting built-in operations, as well as facilities to perform custom computations on the data. For example, a Design Assessment system could be used to obtain solution combinations, to verify a design in relation to a particular standard (e.g. for BEAMCHECK and FATJACK), or to perform custom calculation processes (e.g. fragmentation analyses, calling a third-party program to process results data, or running a Mechanical APDL post processing session).

User Workflow It is useful to understand the user workflow in a Design Assessment system in order to customize its calculation process. A key step in the workflow is to select the upstream system whose results will be examined. This is accomplished using the Solution Selection object. Once specified, there are three considerations that affect the outcome of the calculation process (and can thus be customized): • what inputs are required • what scripts should run • how results should be displayed The user feeds inputs into the Design Assessment system via one or more Attribute Group objects. The scripts are the workhorse for computation. They are programmed in the Python scripting language and have access, at runtime, to all relevant data in the model, including any inputs collected from the user, along with the mesh and upstream results, through an Application Programmable Interface (API). The user defines result requests using the DA Result object to prescribe what quantities to plot and where on the model.

Customization With the exception of Solution Combinations, predefined assessment types such as FATJACK and BEAMST feature Attribute Groups, Scripts, and Result Objects, and can be used as the basis for customization. These three components of the calculation process must be described in the XML definition file before they can be featured in a Design Assessment system. Collectively, the inputs for the process are described in the AttributeGroups section of the Definition File. Each input is controlled by an individual Attribute indicating the type of data to gather from the user, its scope of application on the model, and its validation, among other details. The scripts are prescribed in the DAScripts section of the XML definition file and are the workhorse for computation. Distinct scripts for «Solve» and for «Evaluating Results» are possible to respond to the respective user operations in the Mechanical application editor. Example snippets are provided for each class in the scripting API, along with full worked examples in this documentation. There is a section on Developing and Debugging Scripts for more operation details.

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Using Design Assessment The display of results is configured in the Results section of the XML definition file. Individual Attributes are also used here to collect inputs from the user that can be accessed in the script to control what is to be plotted. Once configured, the XML definition file is imported into Design Assessment as a User Defined type, distinct from all the predefined ones mentioned, and is ready to be used as a custom calculation process. For details, please see the section below on configuring the assessment type.

Design Assessment Types Design Assessment systems offer three predefined types and a user define type (for customization). The predefined types are: • Solution Combination Only • BEAMCHECK • FATJACK To configure a particular Design Assessment system, you may: • Setup cell Right Mouse Button Menu Right click on the Setup cell for the system in the Project Schematic and select Assessment Type. Here you can select one of the pre-defined types, or a user defined type. For user defined types, you could provide the XML definition file from an Open File dialog or a listing of recent files (if available). To identify the selected assessment type, look for a checkmark next to the pre-defined type on the menu. Absence of a checkmark means a user defined type is in effect. or • Setup Cell Properties Panel Select View > Properties from the Main Menu in the Project Schematic. This will display the Properties Panel in the workspace. Now click on the Setup cell of the Design Assessment system and the Properties Panel will be updated to show the available options for the cell. From here you can change the Assessment Type using the drop-down list in the Design Assessment Settings section. You can choose between the predefined types or select User Defined. For user defined types, you can provide the XML definition file from an Open File dialog or a listing of recent files (if available). The name of this file will then be displayed in the properties panel. For User Defined assessment types, the XML definition file will automatically be copied to your project folder upon selection, to keep as a reference. If you subsequently edit your XML definition file and want the changes to be used in a project, it will need to be re-selected. At this stage the differences between

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Predefined Assessment Types the original and the revised XML definition file will be detected and any defined objects will be updated as detailed in Changing the Assessment Type or XML Definition File Contents (p. 1206)

Note If you Import a Mechanical database (e.g., a .mechdat file) containing a Design Assessment system you must reselect the Assessment Type (and associated XML definition file for the User Defined type) before opening the project in the Mechanical application. Otherwise, your assessment type will revert to Solution Combination Only and any Design Assessment objects will be lost. The following sections describe the use of the Design Assessment system. Predefined Assessment Types Changing the Assessment Type or XML Definition File Contents Solution Selection Using the Attribute Group Object Developing and Debugging Design Assessment Scripts Using the DA Result Object The Design Assessment XML Definition File Design Assessment API Reference Examples of Design Assessment Usage

Predefined Assessment Types The following predefined Assessment Types can be selected as described previously after you add a Design Assessment system to the Project Schematic. Solution Combination Only Enables solution combinations of upstream results using the Solution Selection object. Mechanical results can be added to the system. DA result objects can be added for more advanced combination requirements, such as establishing an SRSS combination, or reviewing a combination for maximum values. BEAMCHECK (Beam and Joint Strength) Enables solution combinations of upstream results and post processing with BEAMST. BEAMST performs various regulatory authority based code of practice checks for the ultimate limit state assessment of Beam or Tubular elements. Mechanical results and DA Results objects are available. FATJACK (Beam Joint Fatigue) Enables solution selection of upstream results and post processing with FATJACK. FATJACK (FATigue calculations for offshore JACKets) performs fatigue analysis at the joints of Beam / Tubular based elements for fatigue/service limit state assessment. No Mechanical results are available but DA Results objects can be added to the system. The following sections describe the use of the predefined Assessment Types in the Design Assessment system. Modifying the Predefined Assessment Types Menu Using Advanced Combination Options with Design Assessment Using BEAMST and FATJACK with Design Assessment Using BEAMST with the Design Assessment System Using FATJACK with the Design Assessment System

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Using Design Assessment

Modifying the Predefined Assessment Types Menu The menu of predefined assessment types can be controlled by editing the AttributeTemplate.xml file in the {ANSYS Installation}\v150\Addins\Simulation folder. This file defines what entries appear in the menu when it is selected, along with the order of the entries and the default entry. The User Defined entry is always shown on the Assessment Type menu in addition to the predefined assessment types.

An Example Menu Definition File The following example defines the standard entries on the Assessment Type menu:

FATJACK (Beam Joint Fatigue) DA_FATJACK.xml 1.1 Windows BEAMCHECK (Beam and Joint Strength) DA_BEAMST.xml 1.2 Windows true Solution Combination Only DA_SolutionCombinations.xml 1.5 Windows,Linux

Defining the Menu Entries Each menu entry is defined using an Attribute XML block. The following tags can be defined in the

block. Name: The name that the user will see in the menu. File: The XML definition file that is passed to Mechanical. If the full path to the file is omitted, the location is assumed to be in the {ANSYS Installation}\v150\aisol\DesignSpace\DSPages\xml folder. Priority: The position in the menu, entered as 1.1 — 1.xxx. Default: Specifies which entry is the default. Include this tag with a value of true for the entry that is to be the default option (omit it for other entries). ValidOn: Specifies which platforms are supported for the entry. Available options are Windows and Linux. To specify both platforms, separate entries with a comma (Windows,Linux).

Using Advanced Combination Options with Design Assessment Advanced combination options are available through the addition of DA Result objects when the Assessment Type is Solution Combination Only. They are not available by default with custom XML

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Predefined Assessment Types definition files, even when CombResults =1. These DA Result objects offer similar capability to that offered by the LCOPER command for Mechanical APDL.

Introduction DA Result objects can be added to the Design Assessment system for combining the upstream solution results that have been specified in the Solution Selection table. Different combinations or comparisons can be applied to the selected solutions. Any number of DA Results can be added to combine or compare as many solutions as needed. It is also possible to compare results from the same solution but over different time steps. This is done by selecting the same environment in multiple entries in the Solution Selection table and specifying the desired time steps for those entries.

Defining Results These DA Result objects are similar to those available for the BEAMCHECK and FATJACK assessment types, but have predefined fields that allow you to define the solution combination/comparison method that you want to use. A number of different Result Type and Result Subtype values can be selected to define the combination method. Result Type Choose the Result Type that you want to combine/compare in this DA Result. You can choose one of the following from the drop down list. • Stress • Strain • Displacement • Expression-Based If you choose Stress, Strain, or Displacement as the Result Type, the Entry Value of Attribute 1 will allow you to choose from a drop down list of selected results. The result units are automatically chosen. If a Stress, Strain or Displacement result type is selected, together with a resultant expression (for example, S1 or USUM), the combination/comparison will be performed on the components, and the resultant value recalculated afterwards. This is the same method used by the Mechanical APDL LCOPER command. However in some cases, such as finding the maximum values over a number of time points, this behavior is not desired and the combination/comparison is required to be performed on the resultant of the expression itself. In these cases, select Expression-Based as the result type and enter the expression name in the relevant Attribute box. If Expression-Based is selected, any user defined result can be entered in an expression string in the Entry Value field of Attribute 1. The result unit type must be selected from the drop down list in

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Using Design Assessment the Entry Value field of Attribute 2. Any combination/comparison is performed directly on the expression and does not take into account component values.

Caution This method may produce undesired or nonphysical results. For example, combining USUM vector results would normally be performed on a component basis, and the direct combination of values would most likely cause an undesired result. Result Subtype The Result Subtype field allows you to select the type of combination/comparison operation that you want to perform in this DA Result object. The following operations are available regardless of the Result Type: • Sum results This operation adds the specified results from the selected solutions. • Subtract Results This operation subtracts the specified results from the selected solutions. The lowest solution row number available acts as the minuend and all subsequent solutions act as subtrahends. This can be manipulated using negative coefficients. • Mean Result Sums all selected solution results and divides the total by the number of solutions selected. • SRSS Result Computes the square root of the sum of squares for all selected solution results. • Absolute Maximum Computes the absolute maximum of the selected solution results and sets the DA result to this value with the relevant sign; in other words, the value furthest from zero. For example, if two results with the values 9 and -10 are compared, the DA Result would be set to -10. • Absolute Minimum Similar to Absolute Maximum, but returns the minimum value; in other words, the value closest to zero. • Maximum Finds the maximum result from the selected solution results and sets the DA Result to this value. For example, if two results with the values 9 and -10 are compared, the DA Result would be set to 9. • Minimum Similar to Maximum, but returns the minimum value.

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Predefined Assessment Types Other Attributes • Solutions (By Row Number) This attribute allows the user to compare different solutions within one Design Assessment system. First specify all of the required solutions in the Solution Selection table. Then, using commas and hyphens, you can enter specific solution rows to consider for the current DA Result in this attribute. For example, if solutions 1,2,3,4,7,8,9,10 were required for one combination and 5,6 were required for the other, the you could enter 1-4,7-10 for the first DA Result and 5,6 for the second DA Result. Solution Row numbers are 1 based.

Using BEAMST and FATJACK with Design Assessment The Design Assessment system provides for the selection of Attribute Group objects to define the input data to FATJACK and BEAMST. In addition, DA Result objects can be added to the Solution to define which results to obtain and display. Workbench and Design Assessment are geometry based, which means that areas of the geometry are selected rather than individual elements. With the Mechanical solver, a member ought to be meshed and formed of a number of elements. Results can be added to the Solution in the Design Assessment system and displayed in Workbench; these will contour the maximum value that occurs for each element. Results can be added either before or after the analysis. If additional results are added after the analysis has been performed, then evaluating the results will obtain the values from the existing database, if the result type exists. Elements that do not have results will be shown as semi transparent. Two functions have been added to allow access to the database produced when running BEAMST or FATJACK, The function pyGetElementResultFlt can be used to get an individual specific result, and pyGetElementResultArray can be used to get a number of results for a given range of loads and elements.

Note BEAMST and FATJACK only support Kilogram (Kg) and Pound (Lbm) mass units, and do not support micrometers (µm). The solution should be obtained (including upstream systems) using appropriate units systems, otherwise incorrect results may be obtained when performing the assessment.

Using BEAMST with the Design Assessment System The ability to perform code checking has been incorporated into Workbench using the Design Assessment System. This system can be connected to both Static Structural and Transient Structural systems. The structural analysis needs to be performed using the Mechanical solver. The following sections describe how to setup a BEAMST analysis in the Design Assessment system. Introduction Information for Existing ASAS Users Attribute Group Types Available Results

Introduction The Design Assessment system enables the input of Attribute Group objects to define the input data to BEAMST and DA Result objects to define which results to obtain and present. Workbench and Design Assessment are geometry based, which means that areas of the geometry are selected rather than indiRelease 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Design Assessment vidual elements. With the Mechanical solver, a member ought to be meshed and formed of a number of elements, the Design Assessment, BEAMST implementation automatically sets the unbraced lengths as the distance between the end vertices of the member to account for this. Use the Solution Selection object to identify the results used to produce the combinations for BEAMST. A combination can be formed of a number of Static and Transient Analyses; however, you can only have one analysis with multiple substep results enabled. The results will be associated with the times of the results in the substeps. When using the Design Assessment interface, BEAMST is limited to processing 5000 result time points or loadcases in a single analysis. The number of upstream results is limited to 4999. The limit includes all of the time points from a result, even if BEAMST is only examining a subset of them, and if two separate results are examined from the same upstream system, the total number of results from that system are applied twice to the limit. So, for example, for a typical offshore code check for a transient wave with a combination of transient wave case + three static cases you may have the following entries in the Solution Selection table: Row 1 – Single step from Static Analysis A containing 10 steps (e.g. dead load case A) Row 2 – 1000 substeps from Transient Analysis B containing 4500 substeps in multiple steps (e.g. Transient wave case) Row 3 – Single step from Static Analysis C containing 5 steps (e.g. live load case). Row 4 – Single step from Static Analysis A containing 10 steps (e.g. dead load case B) This would consume 4525 (10 + 4500 + 5 + 10) upstream results and would produce 1000 result time points (each being a combination of the wave + dead A + dead B + live). Results can be added to the Solution in the Design Assessment system and displayed in Workbench; these will contour the maximum value that occurs for each element. Results can be added either before or after the analysis, if further results are added after the analysis has been performed then evaluating the results will obtain the values from the existing database, if the result type exists. Elements that do not have results will be semi transparent. Reports can be produced of the input data and the results can be parameterized and exposed for use with other systems.

Information for Existing ASAS Users BEAMST Command

Attribute Group Type

Attribute Group Subtype

Requirement

ABNO

Load Dependant Factors

Load Classification

API LRFD Only

AISC

Code of Practise Selection

AISC WSD Checks

*

AISC LRFD Checks API

Code of Practise Selection

API WSD Checks

*

API LRFD Checks BRIG

Ocean Environment

Buoyancy Calculation Method

BS59

Code of Practise Selection

BS5950 Checks

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*

Predefined Assessment Types BEAMST Command

Attribute Group Type

Attribute Group Subtype

CASE

Not supported, Load case selection is via the Solution Selection Object

CB

Load Dependant Factors

Bending Coefficient

CHOR

Geometry Definition

Manually Define Chords

Requirement

Define Chord Thickening at Joint Automatic Joint Identification CMBV

Not Supported, only linear static combinations are permitted.

CMY

Load Dependant Factors

Amplification Reduction Factor CMY

CMZ

Load Dependant Factors

Amplification Reduction Factor CMZ

COMB

Automatically determined from the Solution Selection Object

DESI

Automatically determined from the geometry.

DENT

Geometry Definition

Dented Member Profile

ISO Only

DS44

Code of Practise Selection

DS449 / DS412 Checks

*

EFFE

Geometry Definition

Effective Lengths

ELEM

Code of Practise Selection

As selected for the appropriate code of practice

ELEV

Ocean Environment

Water Details

EXTR

Load Dependant Factors

Safety Factor Definition

GAPD

Geometry Definition

Default Gap/Eccentricity

GRAV

Automatic from units, assumed water surface is in global XY plane.

GROU

Not Supported

HYDR

Load Dependant Factors

Safety Factor Definition

ISO

Code of Practise Selection

ISO Checks

JOIN

Code of Practise Selection

As selected for the appropriate code of practice

LIMI

Not Supported

MCOF

Material Definition

Partial Material Coefficient (NPD, NORSOK, DS449 only)

MFAC

Load Dependant Factors

Moment Reduction Factors

MLTF

Load Dependant Factors

LTB Moment Reduction Factor

MOVE

Not Supported

NORS

Code of Practise Selection

NORSOK Checks

*

NPD

Code of Practise Selection

NPD Checks

*

PHI

Load Dependant Factors

PHI Coefficient

POST

Not Supported

PRIN

Not Supported

PROF

Not Supported

QuAK

Load Dependant Factors

Safety Factor Definition

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Using Design Assessment BEAMST Command

Attribute Group Type

RENU

Not Supported

SAFE

Load Dependant Factors

SEAR

Not Supported

SECO

Code of Practise Selection

SECT

Not Supported

SELE

Not Supported

SIMP

Code of Practise Selection

SPEC

Not Supported

STUB

Not Supported

TITL

Not Supported

TYPE

Geometry Definition

Attribute Group Subtype

Requirement

Safety Factor Definition As selected for the appropriate code of practice

BS5950 Checks

Joint Types Default Joint Types

ULCF

Geometry Definition

Unbraced Compression Flange Length Unbraced Compression Flange Length (Factor)

UNBR

Geometry Definition

Unbraced Length Unbraced Length (Factor)

UNIT

Automatically determined from analysis, selections for N mm, pdl ft, pdl in and N m are supported.

WAVE

Ocean Environment

Wave Definition

YIEL

YIEL Material Definition

Yield Definition

Compulsory

* At least one of these entries is required.

Attribute Group Types Attribute Groups enable the entry of the data that is associated with the BEAMST analysis. The following sections describe the available Attribute Group Types and their subtypes. Code of Practise Selection General Text Geometry Definition Load Dependant Factors Material Definition Ocean Environment

Note If units are changed when defining data for Attributes, then the resulting data sent to the processing script may be incorrect. It is recommended that units are not modified from those used in creating the geometry.

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Predefined Assessment Types

Code of Practise Selection All groups that have this type enable the selection of a particular code of practice.

Note If a specific code check version is set to Not Checked for a given code of practice, it is still necessary to make a geometry selection for that Attribute. • API WSD Checks Enables the selection of the API WSD code of practice and the appropriate edition. Use this to select the joints and members to be included in the check. Any members that are not selected will be excluded from the checks. Allowable Stress, Hydrostatic Checks and Joint check clauses will be included as appropriate for the edition chosen. • API LRFD Checks Enables the selection of the API LRFD code of practice and the appropriate edition. Use this to select the joints and members to be included in the check. Any members that are not selected will be excluded from the checks. Allowable Stress Checks, Hydrostatic Checks and Joint check clauses will be included as appropriate for the edition chosen. • AISC WSD Checks Enables the selection of the AISC WSD code of practice and the appropriate edition. Use this to select the members to be included in the check. Any members that are not selected will be excluded from the checks. Allowable Stress Checks clauses will be included as appropriate for the edition chosen. • AISC LRFD Checks Enables the selection of the AISC LRFD code of practice and the appropriate edition. Use this to select the members to be included in the check. Any members that are not selected will be excluded from the checks. Member Checks clauses will be included as appropriate for the edition chosen. • BS5950 Checks Enables the selection of the BS5950 code of practice and the appropriate edition. Use this to select the members to be included in the check. Any members that are not selected will be excluded from the checks. Member Checks clauses will be included as appropriate for the edition chosen. Members that only need the simplified checks can also be selected • DS449 / DS412 Checks

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Using Design Assessment Enables the selection of the DS code of practice and the appropriate edition. Use this to select the joints and members to be included in the check. Any members that are not selected will be excluded from the checks. Allowable Stress and Joint check clauses will be included as appropriate for the edition chosen. • ISO Checks Enables the selection of the ISO code of practice and the appropriate edition. Use this to select the joints and members to be included in the check. Any members that are not selected will be excluded from the checks. Member, Hydrostatic Checks and Joint check clauses will be included as appropriate for the edition chosen. • NORSOK Checks Enables the selection of the NORSOK code of practice and the appropriate edition. Use this to select the joints and members to be included in the check. Any members that are not selected will be excluded from the checks. Member, Hydrostatic Checks and Joint check clauses will be included as appropriate for the edition chosen. • NPD Checks Enables the selection of the NPD code of practice and the appropriate edition. Use this to select the joints and members to be included in the check. Any members that are not selected will be excluded from the checks. Member and Joint check clauses will be included as appropriate for the edition chosen.

General Text This can be used to supply additional and non-supported commands. This will always override data set by other tree objects. • Geometry Independent Enables additional commands to be entered, these will be appended to the end of all code checks.

Geometry Definition All groups that have this type enable the selection of a particular code of practice. • Manually Define Chords The chord member(s) and the central vertex can be chosen to define which members at a joint form the chords. Without this definition, chords are automatically determined. Chords for each Joint needs to be defined separately. Only applicable to joint checks. • Automatic Joint Identification

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Predefined Assessment Types Enables the identification of joints formed of more than one node by the ratio of the distance between nodes to the diameter of the member. All joints can be selected at once. Only applicable to joint checks. • Define Chord Thickening at Joint Enables the entry of chord thickening at the selected joints. Only applicable to joint checks. • Effective Lengths Enables the definition of effective length factor k for the selected members to be entered for both the local y and z directions. Applicable for member strength based checks only. • Unbraced Compression Flange Length Enables the definition of the unbraced compression flange length. If this and the factor version are omitted then the direct distance between vertices which do not have 2 lines joining is taken. • Unbraced Length Enables the definition of the unbraced length. If this and the factor version are omitted then the direct distance between vertices which do not have 2 lines joining is taken. • Joint Types Enables default joint type to be over-ridden. • Default Gap/Eccentricity Enables default gap or eccentricity to be overridden. • Dented Member Profile Enables the definition of dents and imperfections in the straightness of the member to be defined for the ISO code of practice • Unbraced Compression Flange Length (Factor) Enables the definition of the compression flange length. The factor is applied to the distance between vertices which do not have 2 lines joining is taken and is converted to a length. If undefined (and not over-ridden by the direct entry), a factor of 1 is applied to all elements forming the line • Unbraced Length (Factor) Enables the definition of the unbraced length. The factor is applied to the distance between vertices which do not have 2 lines joining is taken and is converted to a length. If undefined (and not overridden by the direct entry), a factor of 1 is applied to all elements forming the line

Load Dependant Factors All groups that have this type enable the entry of values that are dependent on. • Safety Factor Definition

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Using Design Assessment Use this to define if the loading scenario is considered to be an earthQuake/seismic or extreme load, for which the safety factors can be reduced, alternatively, custom values can be added. Additionally the Hydrostatic pressure load factor can be defined for hydrostatic checks. • Load Classification Enables the identification of abnormal load scenarios. Only applies to the API LRFD code of practice. • Bending Coefficient Enables the definition of the pure coefficient of bending, Cb and selection of the members to which it applies. In absence of application of a user value it is calculated automatically. Only applies to the AISC and API allowable stress checks. • PHI Coefficient Enables the specification of the parameter Φ, used in the determination of the lateral buckling strength of beams for NS3472E, this value can either be automatically determined or manually over-ridden. Only applied to the NPD checks. • LTB Moment Reduction Factor Enables the definition and application of MLTB, the moment reduction factor for lateral torsional buckling. Only applicable to BS5950 • Amplification Reduction Factor CMY Enables the definition and application of the factor Cmy, the amplification reduction factor. Only applies to AISC & API Allowable stress checks. • Amplification Reduction Factor CMZ Enables the definition and application of the factor Cmz, the amplification reduction factor. Only applies to AISC & API Allowable stress checks • Moment Reduction Factors Enables the definition and application of the My and Mz factors, the moment reduction factors. Only applies to BS5950 checks.

Material Definition All groups that have this type enable the selection of a particular code of practice. • Partial Material Coefficients Enables the definition of the partial material coefficients utilised in the NPD, NORSOK and DS449 codes • Yield Definition Definition of the yield stress, must have a value applied for each member in the analysis. Required for all code checks

1170

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Predefined Assessment Types

Ocean Environment All groups that have this type enable the selection of a particular code of practice. • Water Details Enables the elevation of the mean water level, sea bed to be defined in global Z. Water density and tide/surge heights can also be entered. Required for all code checks involving hydrostatic analysis.

Note The global X/Y plane is coincident with the horizontal mean sea level, with global Z vertically upwards (away from the mudline).

• Buoyancy Calculation Method By default rigorous buoyancy is enabled for compatibility with the Mechanical analysis methods. If necessary, this methodology can be disabled for the code check. • Wave Definition Used to specify the wave height and period for the calculation for wave induced hydrostatic pressure head calculations.

Available Results The following results are available for the Code of Practice types as indicated below. Results are added using the DA Results tree object. AISC LRFD Results AISC WSD Results API LRFD Results API WSD Results BS5950 Results DS449 High Results DS449 Normal Results ISO Results NORSOK Results NPD Results As each result object presents a number of types of results, units are not employed in the output. Hence all values will be reported in the solver units used for the BEAMST analysis.

AISC LRFD Results Two Results subtypes are available for this code of practice. The results available for those subtypes are shown below. Member Unity Checks • Axial • Y Shear

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1171

Using Design Assessment • Z Shear • Y Bending • Z Bending • Buckling CSR • Yield Member General Results • Y Amplification Reduction Factor • Z Amplification Reduction Factor • Allowable Axial Stress • Critical Stress • Allowable Y Euler Buckling Stress • Allowable Z Euler Buckling Stress • Allowable Y Shear Stress • Allowable Z Shear Stress • Allowable Y Bending Stress • Allowable Z Bending Stress

AISC WSD Results Two Results subtypes are available for this code of practice. The results available for those subtypes are shown below. Member Unity Check • Axial • Y Shear • Z Shear • Y Bending • Z Bending • Maximum Shear • Buckling • Buckling CSR • Yield

1172

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Predefined Assessment Types Member General Results • Y Amplification Reduction Factor • Z Amplification Reduction Factor • Allowable Axial Stress • Allowable Shear Stress • Allowable Y Bending Stress • Allowable Z Bending Stress

API LRFD Results Six Results subtypes are available for this code of practice. The results available for those subtypes are shown below. Member Unity Checks • Axial • Shear • Torsion • Y Bending • Z Bending • Resultant Bending • Buckling • Buckling CSR • Yield 1 • Yield 2 Hydrostatic Unity Checks • Axial • Hoop • Yield • Buckling • Combined Joint Unity Check • Axial

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1173

Using Design Assessment • In-Plane Bending • Out-of-Plane Bending • Bending • Combined Axial + Bending • Joint Strength Hydrostatic General Results • Hydrostatic Depth • Hydrostatic Pressure Load Factor • Geometry Parameter • Hoop Buckling Coefficient • Hoop Stress • Allowable Axial Stress • Allowable Bending Stress • Allowable Elastic Axial Stress • Allowable Elastic Hoop Stress • Allowable Inelastic Axial Stress • Allowable Inelastic Hoop Stress Joint General Results • Proportion of Joint 1 • Proportion of Joint 2 • Gap • Beta Ratio • Tau Ratio • Theta Angle • Chord Stress • Chord Yield Stress • Brace Yield Stress • Brace Axial Stress • In-Plane Brace Bending Stress

1174

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Predefined Assessment Types • Out-of-Plane Brace Bending Stress • Axial Qf Factor • In-Plane Qf Factor • Out-of-Plane Qf Factor • Axial Qu Factor Brace 1 • In-Plane Bending Qu Factor Brace 1 • Out-of-Plane Bending Qu Factor Brace 1 • Axial Qu Factor Brace 2 • In-Plane Bending Qu Factor Brace 2 • Out-of-Plane Bending Qu Factor Brace 2 • Axial Force • In-Plane Bending Force • Out-of-Plane Bending Force • Allowable Axial Force Brace 1 • Allowable In-Plane Bending Force Brace 1 • Allowable Out-of-Plane Bending Force Brace 1 • Allowable Axial Force Brace 2 • Allowable In-Plane Bending Force Brace 2 • Allowable Out-of-Plane Bending Force Brace 2 • Allowable Cross Chord Force Member General Results • Y Amplification Reduction Factor • Z Amplification Reduction Factor • Column Slenderness Parameter • Allowable Axial Stress • Allowable Shear Stress • Allowable Torsion Stress • Allowable Bending Stress • Allowable Y Euler Buckling Stress Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

1175

Using Design Assessment • Allowable Z Euler Buckling Stress • Yield Stress • Buckling Stress

API WSD Results Eleven Results subtypes are available for this code of practice. The results available for those subtypes are shown below. Member Unity Checks • Axial • Y Shear (not TUBE — Ed17+) • Z Shear (not TUBE — Ed17+) • Y Bending • Z Bending • Buckling • Buckling CSR • Yield • Maximum Shear (TUBE — Ed13 Only) • Flexural Shear (TUBE — Ed17+) • Torsional Shear (TUBE — Ed17+) • Resultant Bending (TUBE — Ed17+) Hydrostatic Unity Checks • Axial Tension • Hoop • Combined 1 • Combined 2 • Combined T Joint (Punching) Unity Checks • Axial • In-Plane Bending • Out-of-Plane Bending

1176

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Predefined Assessment Types • Bending • Combined Axial + Bending • Joint Strength Joint (Nominal) Unity Checks • Axial • In-Plane Bending • Out-of-Plane Bending • Bending • Combined Axial + Bending • Joint Strength Joint Unity Checks • Axial • In-Plane Bending • Out-of-Plane Bending • Combined Axial + Bending Hydrostatic General Results • Hydrostatic Depth • Hoop Stress • Allowable Axial Tension Stress • Allowable Elastic Axial Stress • Allowable Elastic Hoop Stress • Allowable Inelastic Axial Stress • Allowable Inelastic Hoop Stress Joint (Nominal) General Results • Gap • Beta Ratio • Tau Ratio • Theta Angle • Chord Stress Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

1177

Using Design Assessment • Chord Yield • AISC Allowable Punching Shear Stress • Brace Axial Stress • In-Plane Brace Bending Stress • Out-of-Plane Brace Bending Stress • Axial Qf Factor • In-Plane Qf Factor • Out-of-Plane Qf Factor • Axial Qu Factor Brace 1 • In-Plane Bending Qu Factor Brace 1 • Out-of-Plane Bending Qu Factor Brace 1 • Axial Qu Factor Brace 2 • In-Plane Bending Qu Factor Brace 2 • Out-of-Plane Bending Qu Factor Brace 2 • Axial Force • In-Plane Bending Force • Out-of-Plane Bending Force • Allowable Axial Force Brace 1 • Allowable In-Plane Bending Force Brace 1 • Allowable Out-of-Plane Bending Force Brace 1 • Allowable Axial Force Brace 2 • Allowable In-Plane Bending Force Brace 2 • Allowable Out-of-Plane Bending Force Brace 2 Joint General Results • Allowable Pa • Allowable Ma In-Plane • Allowable Ma Out-of-Plane • Beta Ratio • Gamma Ratio

1178

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Predefined Assessment Types • Tau Ratio • Theta Angle • 1st Chord Member • Chord Axial Force • Chord Moment In-Plane • Chord Moment Out-of-Plane • Chord Capacity • Chord Strength • Brace Axial Force • Brace Moment In-Plane • Brace Moment Out-of-Plane • Joint Proportion (%) 1 • Joint Proportion (%) 2 • Joint Proportion (%) 3 • Joint Proportion (%) 4 • Joint Proportion (%) 5 • Axial Qu Factor 1 • Axial Qu Factor 2 • Axial Qu Factor 3 • Axial Qu Factor 4 • Axial Qu Factor 5 • Axial Qf Factor 1 • Axial Qf Factor 2 • Axial Qf Factor 3 • Axial Qf Factor 4 • Axial Qf Factor 5 • Gap Factor 1 • Gap Factor 2 • Gap Factor 3 Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

1179

Using Design Assessment • Gap Factor 4 • Gap Factor 5 • Qu Factor — In-Plane • Qu Factor — Out-of-Plane • Qf Factor Joint (Punching) Results • Proportion of Joint 1 • Proportion of Joint 2 • Gap • Beta Ratio • Tau Ratio • Theta Angle • Chord Stress • Chord Yeild • AISC Allowable Punching Shear Stress • Brace Axial Stress • In-Plane Brace Bending Stress • Out-of-Plane Brace Bending Stress • Axial Qf Factor • In-Plane Qf Factor • Out-of-Plane Qf Factor • Axial Qq Factor Brace 1 • In-Plane Bending Qq Factor Brace 1 • Out-of-Plane Bending Qq Factor Brace 1 • Axial Qq Factor Brace 2 • In-Plane Bending Qq Factor Brace 2 • Out-of-Plane Bending Qq Factor Brace 2 • Axial Stress • In-Plane Bending Stress

1180

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Predefined Assessment Types • Out-of-Plane Bending Stress • Allowable Axial Stress Brace 1 • Allowable In-Plane Bending Stress Brace 1 • Allowable Out-of-Plane Bending Stress Brace 1 • Allowable Axial Stress Brace 2 • Allowable In-Plane Bending Stress Brace 2 • Allowable Out-of-Plane Bending Stress Brace 2 Member General Results • Y Amplification Reduction Factor • Z Amplification Reduction Factor • Critical Buckling (Bending) • Allowable Axial Stress • Allowable Shear Stress • Allowable Y Bending Stress (Not TUBE Ed17 On) • Allowable Z Bending Stress (Not TUBE Ed17 On) • Allowable Torsion Stress (TUBE Ed17 On) • Allowable Bending Stress (TUBE Ed17 On) Spectral Results • Y Amplification Reduction Factor • Z Amplification Reduction Factor • Allowable Axial Stress • Allowable Y Bending Stress (Not TUBE Ed16 On) • Allowable Z Bending Stress (Not TUBE Ed16 On) • Allowable Euler Buckling Stress Y • Allowable Euler Buckling Stress Z • Maximum Axial Stress • Maximum Y Bending Stress • Maximum Z Bending Stress

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1181

Using Design Assessment

BS5950 Results Two Results subtypes are available for this code of practice. The results available for those subtypes are shown below. Member Unity Checks • Major Axis Bending • Minor Axis Bending • Major Axis Shear • Minor Axis Shear • Axial Tension • Combined Axial + Moment • Minor Axis Buckling • Major Axis Buckling • Lateral Torsional Buckling • Overall Buckling Member General Results • Axial Force Capacity • Major Axis Shear Force Capacity • Minor Axis Shear Force Capacity • Major Axis Bending Moment Capacity • Minor Axis Bending Moment Capacity • Reduced Moment Capacity — Major Axis • Reduced Moment Capacity — Minor Axis • Member Compressive Capacity — Minor Axis Buckling • Member Compressive Capacity — Major Axis Buckling • Member Moment Capacity — Lateral Torsional Buckling

DS449 High Results Four Results subtypes are available for this code of practice. The results available for those subtypes are shown below. Member Unity Checks • Von Mises 1182

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Predefined Assessment Types • Shear • Local Buckling • Y Total Buckling • Z Total Buckling • Hydrostatic Overpressure • Combined Local + Hydrostatic Joint (Nominal) Unity Check • Axial • In-Plane Bending • Out-of-Plane Bending • Bending • Combined Axial + Bending Member General Results • Von Mises Stress • Hoop Stress (H) • Hydrostatic Pressure (H) • Relative Slenderness Ratio For Local Buckling • Critical Stress For Local Buckling • Critical Stress For Hydrostatic Overpressure (H) • Critical Stress For Combined Case (H) • Critical Pressure (H) • Maximum Axial Force • Y Equivalent Design Moment • Z Equivalent Design Moment • Y Euler Buckling Force • Z Euler Buckling Force • Y Relative Slenderness Ratio • Z Relative Slenderness Ratio • Y Equivalent Geometric/Material Imperfections Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

1183

Using Design Assessment • Z Equivalent Geometric/Material Imperfections • Critical Stress Joint General Results • Proportion of Joint 1 • Proportion of Joint 2 • Gap • Beta Ratio • Tau Ratio • Theta Angle • Gamma Ratio • Chord Stress • Chord Yield Stress • Chord Wall Shear Limit • Brace Axial Stress • Brace In-Plane Bending Stress • Brace Out-of-Plane Bending Stress • Axial UU Factor • In-Plane UU Factor • Out-of-Plane UU Factor • Axial Ten/Comp CC Factor For Brace 1 • In-Plane Bending CC Factor For Brace 1 • Out-of-Plane Bending CC Factor For Brace 1 • Axial Ten/Comp CC Factor For Brace 2 • In-Plane Bending CC Factor For Brace 2 • Out-of-Plane CC Factor For Bending Brace 2 • Axial Nominal Load • In-Plane Bending Moment • Out-of-Plane Bending Moment • Axial Capacity Brace 1

1184

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Predefined Assessment Types • In-Plane Bending Capacity Brace 1 • Out-of-Plane Bending Capacity Brace 1 • Axial Capacity Brace 2 • In-Plane Bending Capacity Brace 2 • Out-of-Plane Bending Capacity Brace 2

DS449 Normal Results Two Results subtypes are available for this code of practice. The results available for those subtypes are shown below. Member Unity Checks • Von Mises • Shear • Local Buckling • Y Total Buckling • Z Total Buckling • Hydrostatic Overpressure • Combined Local + Hydrostatic Member General Results • Von Mises Stress • Hoop Stress (H) • Hydrostatic Pressure (H) • Relative Slenderness Ratio For Local Buckling • Critical Stress For Local Buckling • Critical Stress For Hydrostatic Overpressure (H) • Critical Stress For Combined Case (H) • Critical Pressure (H) • Maximum Axial Force • Y Equivalent Design Moment • Z Equivalent Design Moment • Y Euler Buckling Force

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1185

Using Design Assessment • Z Euler Buckling Force • Y Relative Slenderness Ratio • Z Relative Slenderness Ratio • Y Equivalent Geometric/Material Imperfections • Z Equivalent Geometric/Material Imperfections • Critical Stress

ISO Results Six Results subtypes are available for this code of practice. The results available for those subtypes are shown below. Member Unity Checks • Axial • Shear • Torsion • Y Bending • Z Bending • Resultant Bending • Yield 1 • Yield 2 Hydrostatic Unity Checks • Hoop Compressive • Combined Hoop + Axial • Combined Hoop Bending + Axial 1 • Combined Hoop Bending + Axial 2 • Combined Joint Unity Check • Axial • In-Plane Bending • Out-of-Plane Bending • Combined Axial + Bending

1186

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Predefined Assessment Types Member General Results • Y Moment Amplification Reduction Factor • Z Moment Amplification Reduction Factor • Column Slenderness Parameter • Allowable Axial Stress • Allowable Shear Stress • Allowable Torsion Stress • Allowable Y Bending Stress • Allowable Z Bending Stress • Allowable Y Euler Buckling Stress • Allowable Z Euler Buckling Stress • Allowable Local Buckling Stress Hydrostatic General Results • Section Position • Hydrostatic Depth • Hydrostatic Load Factor • Geometry Parameter • Hoop Buckling Coefficient • Hoop Stress • Allowable Axial Stress • Allowable Bending Stress • Allowable Elastic Axial Stress • Allowable Inelastic Axial Stress • Allowable Elastic Hoop Stress • Allowable Inelastic Hoop Stress Joint General Results • Allowable Pa • Allowable Ma In-Plane • Allowable Ma Out-of-Plane Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

1187

Using Design Assessment • Beta Ratio • Gamma Ratio • Tau Ratio • Theta Angle • Chord Axial Force • Chord Moment In-Plane • Chord Moment Out-of-Plane • Chord Capacity • Chord Strength • Brace Axial Force • Brace Moment In-Plane • Brace Moment Out-of-Plane • Joint Proportion (%) 1 • Joint Proportion (%) 2 • Joint Proportion (%) 3 • Joint Proportion (%) 4 • Joint Proportion (%) 5 • Axial Qu Factor 1 • Axial Qu Factor 2 • Axial Qu Factor 3 • Axial Qu Factor 4 • Axial Qu Factor 5 • Axial Qf Factor 1 • Axial Qf Factor 2 • Axial Qf Factor 3 • Axial Qf Factor 4 • Axial Qf Factor 5 • Gap Factor 1 • Gap Factor 2

1188

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Predefined Assessment Types • Gap Factor 3 • Gap Factor 4 • Gap Factor 5 • Qu Factor — In Plane • Qu Factor — Out Of Plane • Qf Factor — In Plane • Qf Factor — Out Of Plane

NORSOK Results Six Results subtypes are available for this code of practice. The results available for those subtypes are shown below. Member Unity Checks • Axial • Shear • Torsion • Y Bending • Z Bending • Resultant Bending • Bending + Shear • Shear + Bending + Torsion • Yield 1 • Yield 2 Hydrostatic Unity Checks • Hoop Compressive • Combined Hoop + Axial • Combined Hoop Bending + Axial 1 • Combined Hoop Bending + Axial 2 • Combined Joint Unity Check • Axial

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1189

Using Design Assessment • In-Plane Bending • Out-of-Plane Bending • Combined Axial + Bending Member General Results • Y Moment Amplification Reduction Factor • Z Moment Amplification Reduction Factor • Chord Diameter • Chord Thickness • Column Slenderness Parameter • Allowable Axial Stress • Allowable Shear Stress • Allowable Torsion Stress • Allowable Bending Stress • Allowable Y Euler Buckling Stress • Allowable Z Euler Buckling Stress • Allowable Yield Hydrostatic General Results • Hydrostatic Depth • Geometry Parameter • Hoop Buckling Coefficient • Hoop Stress • Allowable Axial Stress • Allowable Bending Stress • Allowable Elastic Axial Stress • Allowable Inelastic Axial Stress • Allowable Elastic Hoop Stress • Allowable Inelastic Hoop Stress Joint (Nominal) General Results • Gap

1190

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Predefined Assessment Types • Beta Ratio • Tau Ratio • Theta Angle • Chord Stress • Chord Yield Stress • Brace Yield Stress • Brace Axial Stress • In-Plane Brace Bending Stress • Out-of-Plane Brace Bending Stress • Axial Qf Factor • In-Plane Bending Qf Factor • Out-of-Plane Bending Qf Factor • Axial Qu Factor Brace 1 • In-Plane Bending Qu Factor Brace 1 • Out-of-Plane Bending Qu Factor Brace 1 • Axial Qu Factor Brace 2 • In-Plane Bending Qu Factor Brace 2 • Out-of-Plane Bending Qu Factor Brace 2 • Axial Force • In-Plane Bending Force • Out-of-Plane Bending Force • Allowable Axial Force Brace 1 • Allowable In-Plane Bending Moment Brace 1 • Allowable Out-of-Plane Bending Moment Brace 1 • Allowable Axial Force Brace 2 • Allowable In-Plane Bending Moment Brace 2 • Allowable Out-of-Plane Bending Moment Brace 2 • Chord Effective Length

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1191

Using Design Assessment

NPD Results Nine Results subtypes are available for this code of practice. The results available for those subtypes are shown below. Member Unity Checks (1984) • Axial • Bending (TUBE) • Lateral Pressure (TUBE) • Torsional Shear (TUBE) • Bending Shear (TUBE) • Von Mises • Axial + Bending Combined (TUBE) • Axial + Lateral Pressure (TUBE) • Axial + Torsion (TUBE) • Axial + Bending Shear (TUBE) • Y Shear (BEAM) • Z Shear (BEAM) • Y Total (Overall) • Z Total (Overall) Joint (Punching) Unity Checks (1984) • Punching • Yield Member Unity Checks (1992) • Von Mises (Yield) • Y Total (Overall) • Z Total (Overall) Joint Unity Checks (1992) • Axial • In-Plane Bending • Out-of-Plane Bending

1192

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Predefined Assessment Types • Combined Axial + Bending Member Local General Results (1984) • Section Position • Axial Stress • Bending Stress (TUBE) • Hoop Stress (TUBE) • Von Mises Stress • Shear Stress Due To Torsion (TUBE) • Shear Stress Due To Bending (TUBE) • Relative Slenderness Ratio (Axial) (TUBE) • Relative Slenderness Ratio (Bending) (TUBE) • Relative Slenderness Ratio (Lateral Pressure) (TUBE) • Relative Slenderness Ratio (Shear) (TUBE) • Critical Buckling Stress (Axial) (TUBE) • Critical Buckling Stress (Bending) (TUBE) • Critical Buckling Stress (Lateral Pressure) (TUBE) • Critical Buckling Stress (Shear) (TUBE) • Maximum Y Shear Stress (BEAM) • Maximum Z Shear Stress (BEAM) Member Overall General Results (1984) • Y Equivalent Moment • Z Equivalent Moment • Y Relative Slenderness Ratio • Z Relative Slenderness Ratio • FKY To Yield Stress Ratio • FKZ To Yield Stress Ratio • Y Theoretical Buckling Load • Z Theoretical Buckling Load • Y Euler Buckling Load Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

1193

Using Design Assessment • Z Euler Buckling Load • Y Ultimate Bending Capacity • Z Ultimate Bending Capacity • Critical Torsional Axial Stress • Revised Buckling Strength Member General Results (1992) • Axial Stress • Bending Stress • Hoop Stress • Von Mises Stress • Torsional Stress • Maximum Bending Shear Stress • Y Equivalent Moment • Z Equivalent Moment Joint General Results (1984) • Theta Angle • Beta Ratio • Tau Ratio • Gamma Ratio • Joint Geometry Factor • Chord Stress Factor • Brace Axial Stress • In-Plane Brace Bending Stress • Out-of-Plane Brace Bending Stress • Chord Axial Stress • Chord Bending Stress • Chord Shear Yield Stress • Acting Punching Shear • Critical Joint Punching Shear Stress

1194

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Predefined Assessment Types Joint General Results (1992) • Theta Angle • Beta Ratio • Gamma Ratio • Brace Axial Stress • Brace In-Plane Stress • Brace Out-of-Plane Stress • Chord Axial Stress • Chord Y Bending Stress • Chord Z Bending Stress

Using FATJACK with the Design Assessment System The ability to perform joint fatigue assessment has been incorporated into Workbench using the Design Assessment System. This system can be connected to Static Structural, Transient Structural, and Harmonic Response systems as required. See Analysis Type Selection (p. 1198) for more details of the appropriate upstream systems. The structural analysis needs to be performed using the Mechanical solver. The following sections describe how to setup a FATJACK analysis in the Design Assessment system. Introduction Information for Existing ASAS Users Solution Selection Customization Attribute Group Types Available Results

Introduction Attribute Group objects are added to the Design Assessment system to define the input data to FATJACK. DA Result objects are added to the Design Assessment system to define which results to obtain and display. Workbench and Design Assessment are geometry based, which means that areas of the geometry are selected rather than individual elements. With the Mechanical solver, a member ought to be meshed and formed of a number of elements. Some data associated to the upstream solutions is entered in the solution selection table. Results can be added to the Solution in the Design Assessment system and displayed in Workbench; these will contour the maximum value that occurs for each element. Results can be added either before or after the analysis. If additional results are added after the analysis has been performed, then evaluating the results will obtain the values from the existing database, if the result type exists. Elements that do not have results will be semi transparent. Results are for the end of the brace and are shown on the brace element. Reports can be produced of the input data and the results can be parameterized and exposed for use with other systems.

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1195

Using Design Assessment

Information for Existing ASAS Users FATJACK Command

Attribute Group Type

Attribute Group Subtype

Requirement

ANALYSIS

Analysis Type Selection

Time History, Spectral, Stress History, and Deterministic

Compulsory

ACCE

Automatically defined based on units, Analysis type Spectral only.

ALLO

Analysis Type Selection

Stress History

CHOR

Geometry Definition

Chord Definition

CURV

Material Definitions

S-N Curve Definition

Compulsory

CYCL

Analysis Type Selection

Time History

Compulsory for Time History analysis types

DESI

Automatically determined from the geometry

DETE

Data is entered via Structure Selection table for analysis type Time History. For Deterministic and Stress History analysis types, the information should be provided in a separate file.

Compulsory for Deterministic and Stress History Analysis Types

FREQ

Supply in a separate file with SPEC and TRAN data, referenced in Analysis Type for Spectral analyses.

Compulsory for Spectral analysis types

GAP

Geometry Definition

Gap Definition

GAPD

Geometry Definition

Default Gap

HIST

Data is entered via Structure Selection table

INSE

Geometry Definition

Inset

INSP

Joint Inspection Points

Tubular Members, By Number

Compulsory for Time History analyses

Tubular Members, By List of Angles Non-Tubular Members, By Symmetric Positions Non-Tubular Members, By Individual Positions JOIN

Analysis Type Selection

LIMI

Not Supported, can be added using General Text input

PARA

Not Supported, can be added using General Text input

PRIN

Automatically defined as PRIN FULL DETA USAG XCHE SCFE SCFP DAMW, plus OCUR, OCRW or OCRT for Spectral Analyses or plus RNGE or PEAK for Stress History Analyses, both depending upon the option entered in the Analysis definition. If different text output is required, then it can be added using General Text input.

REDU

SCF Definitions

Marshall Reduction

SCF

SCF Definitions

Default Values

SCF ANGLE

SCF Definitions

Joint Values, Tubular (Inspection Point by Angle)

1196

Time History, Spectral, Stress History, and Deterministic

Compulsory

Compulsory

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Predefined Assessment Types FATJACK Command

Attribute Group Type

Attribute Group Subtype

SCF AUTO DEFAULT

SCF Definitions

Default Empirical Formulation by Joint Type

SCF AUTO JOINT

SCF Definitions

Empirical Formulation by Joint

SCFBRACE

SCF Definitions

Joint Values, Non-Tubular (All Inspection Points)

SCFJOINT

SCF Definitions

Brace Side Joint Values, Tubular (Crown + Saddle)

Requirement

Chord Side Joint Values, Tubular (Crown + Saddle) SCFMINIMUM

SCF Definitions

Minimum Value

SCFPOINT

SCF Definitions

Joint Values, Non-Tubular (Inspection Point by Position)

SECO

Geometry Definition

Excluded Members

SIGM

Not Supported

Analysis Type for Spectral analyses Compulsory for Spectral analysis

S-N

Material Definitions

S-N Curve Application

SPEC

Supply in a separate file with FREQ and TRAN data

Analysis Type for Spectral analyses Compulsory for Spectral analysis

SPRE

Not Supported

Analysis Type for Spectral analyses Compulsory for Spectral analysis

THIC

Material Definitions

S-N Thickness Modification

TRAN

Supply in a separate file with FREQ and SPEC data

Analysis Type for Spectral analyses Compulsory for Spectral analysis

TYPE

Geometry Definition

Joint Type (Single Brace)

Compulsory

Joint Type (Multiple Braces) UNIT

Automatically determined from analysis, selections for N mm, pdl ft, pdl in and N m are supported.

WAVE

WAVE AUTO Automatically included for Spectral, Deterministic and Stress History analysis types, use General Text entry to override if specific control is required.

YEAR

Analysis Type Selection

Time History, Spectral, Stress History, and Deterministic

Compulsory

Solution Selection Customization The Solution Selection object for FATJACK has additional columns for the entry of the range of steps to use for rainflow counting (start step, end step, and interval between steps). Also, the occurrence data for each environment can be defined either by number of cycles per year and an amplification factor, or by probability. If a probability is entered this will be used instead of cycles per year. A consistent method needs to be used throughout all solution environments. This data is only applicable for Time History based analyses. For Stress History and Deterministic methods the occurrence data is defined externally, referenced in the analysis type. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Design Assessment

Attribute Group Types Attribute Groups enable the entry of the data that is associated with the FATJACK analysis. The following sections describe the available Attribute Group Types and their subtypes. Analysis Type Selection General Text Geometry Definition Joint Inspection Points SCF Definitions Material Definition Ocean Environment Some attribute groups are compulsory, indicated by superscript letters as follows: TH – compulsory for Time History based analyses SH – compulsory for Stress History based analyses SP – compulsory for Spectral based analyses DT – compulsory for Deterministic based analyses C – compulsory for all analyses

Note If units are changed when defining data for Attributes, then the resulting data sent to the processing script may be incorrect. It is recommended that units are not modified from those used in creating the geometry.

Analysis Type Selection All types of fatigue analysis supported with this interface. Add an Attribute Group under the Design Assessment object in the tree, and set the Attribute Group Type to Analysis Type Selection. The Attribute Group Subtype can be set to one of the following values, and the associated attributes for that subtype can be set: • Time HistoryTH Enables the selection of which joints are to be included, along with definition of the rainflow counting information (Number of Intervals, Peak Stress Range Required, and Stress Range Limit (1st Interval) attributes) and Target Year Life of the analysis. Upstream systems should be Structural Transient, normally each including randomized ocean loading with different wave directions. • Stress HistorySH Enables the selection of which joints are to be included, along with definition of the Target Year Life of the analysis. Wave occurrence data should be provided in a text file containing the FATJACK commands. Select this file using the browse button for the Deterministic Data attribute. Wave conditions (heights, periods, directions) are automatically determined from the ocean loading provided in upstream system(s) in the order that they are defined. Upstream systems can be either static structural or transient structural. If loading is not applied using the ocean loading, then an additional attribute group of the type General Text can be used to define the WAVE commands. If the value for 1198

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Predefined Assessment Types the Allowable Stress attribute is set to zero, then actual stresses will be output; if a value is entered, then utilization factors will be output. These values will either be the Peak or Full Range values as specified in the Stress Range Output attribute. • SpectralSP Enables the selection of which joints are to be included, along with definition of the Wave Spreading and Target Year Life of the analysis. Wave transfer function, spectrum, and additional frequency data should be provided in a text file containing the FATJACK commands. Select this file using the browse button for the Spectrum Data attribute. Wave load cases are automatically determined using the harmonic ocean wave procedure provided in upstream system(s) in the order that they are defined. Upstream systems should be of the Harmonic Response type; both the Static and Harmonic options of the HROCEAN command can be used when performing Spectral analysis. The Stress Histogram Results Output (tables of number of cycles against stress range) attribute may be Enabled and optionally set to output results By Transfer Function or By Spectrum. Unless Stress Histogram Results Output is Disabled, a valid Peak Stress Range Required attribute must be defined, together with the number of reporting intervals (Number of Intervals attribute). If Stress Histogram Results Output is Disabled, values must be entered for Peak Stress Range Required and Number of Intervals, but they are not used. • DeterministicDT Enables the selection of which joints are to be included, along with definition of the Target Year Life of the analysis. Wave occurrence data should be provided in a text file containing the FATJACK commands. Select this file using the browse button for the Deterministic Data attribute. Wave load cases are automatically determined using the harmonic ocean wave procedure provided in upstream system(s) in the order that they are defined. Upstream systems should be of harmonic response type; only the Static option of the HROCEAN command is appropriate for Deterministic analysis.

Note References to ocean loading assume the input of MAPDL commands using Commands objects in upstream Mechanical systems.

General Text This can be used to supply additional and non-supported commands. This will always override data set by other tree objects. • Geometry Independent Enables additional commands to be entered that will be appended to the end of all code checks.

Geometry Definition All groups that have this type enable the selection of a particular code of practice. • Chord Definition The chord member(s) and the central vertex can be chosen along with the length of the chord and fixity parameters to define which members at a joint form the chords. Without this definition, chords are automatically determined. Chords for each Joint need to be defined separately. Only applicable to joint checks. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Design Assessment • Gap Definition Enables specific gap information to be defined between the pairs of braces forming KT or K joints, and to determine which member is the through member. • Default Gap Enables the entry of the default gap size to use for the given equations. • Inset Enables a distance to be entered to allow for moment backoff. • Joint Type (Single Brace) Enables the manual definition of joint type when only a single brace is connected. • Joint Type (Multiple Braces) Enables the manual definition of joint type when more than one brace is connected. • Excluded Members Enables members that are to be excluded from the joint checks to be selected.

Joint Inspection Points Inspection points are the positions to check for fatigue around the brace where it connects to the chord. • Tubular Members, By Number Use this to define the number of inspection points equally spaced around tubular members. • Tubular Members, By List of Angle Use this to define a list of space separated angles that define the inspection points spaced around tubular members at an individual joint. • Non-Tubular Members, By Symmetric Positions Use this to define inspection points for selected non-tubular members by defining Z and Y offset distances from the centre of the member to generate 4 points for the positive and negative combinations. • Non-Tubular Members, By Individual Positions Use this to define specific inspection points on an individual joint, by a list of y z pairs, space separated.

SCF Definitions All groups that have this type enable the entry of values that define the stress concentration factors. • Marshall Reduction Use this to define the Marshall Reduction factor for the brace side SCF values when using the Kuang equations.

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Predefined Assessment Types • Default ValuesC Use this to specify the default SCF values for a given section type. • Chord Side Joint Values, Tubular (Crown + Saddle) Use this to specify user defined crown and saddle SCF values for the chord side of tubular braces at specific joints. • Brace Side Joint Values, Tubular (Crown + Saddle) Use this to specify user defined crown and saddle SCF values for the brace side of tubular braces at specific joints. • Joint Values, Non-Tubular (All Inspection Points) Use this to specify the SCF values at all inspection points on non tubular braces. • Joint Values, Tubular (Inspection Point by Angle) Use this to specify the SCF values at specific inspection points on tubular braces. • Joint Values, Non-Tubular (Inspection Point by Position) Use this to specify the SCF values at specific inspection points on non tubular braces. • Empirical Formulation by Joint Use this to specify that the empirical equations to be utilized for the SCF generation for the given joint selection. • Default Empirical Formulation by Joint Type Use this to specify the default empirical equations to be utilized for the SCF generation for the given joint type. • Minimum Value Use this to set the minimum SCF value in the analysis.

Material Definition All groups that have this type enable the selection of a particular code of practice. • S-N Curve ApplicationC Use this to define which S-N Curve applies to selected area of the model. Enter the same name as used in the S-N Curve Definition. • S-N Thickness Modification Use this to request the modification of the S-N curves to account for varying plate thickness. • S-N Curve DefinitionC

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Using Design Assessment Use this to define an S-N curve for use in the analysis; the name is limited to 4 characters in length.

Ocean Environment All groups that have this type define wave occurrence data in the ocean environment, if a large number of occurrence data needs to be entered, then general entry can be used to reference an external file containing the data. • Additional Wave Occurrence Data Use this to define a single line of additional wave occurrence data; i.e., additional wave height, direction, and number of cycle definitions. Only applicable to Deterministic and Stress History analysis types.

Available Results The following results are available as indicated below. Results are added using the DA Results tree object. • Damage Values* • Fatigue Assessment*# • SCF Values# • Stress Histogram Results • Stress Range Results * To obtain these results for Spectral Analyses, Stress Histogram Results Output needs to be set to Disabled. # To obtain these results for Stress History Analyses, Stress Range Output needs to be set to Disabled. When retrieving results from a FATJACK analysis, you have the option of specifying how the value of the result is determined among all of the inspection points, using the Result Value Option and Specified Inspection Point attributes.

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Predefined Assessment Types

Result Value Option This attribute and the Specified Inspection Point (if needed) allow you to specify how the results are retrieved. • Maximum – Retrieves the maximum value across the inspection points (default) • Minimum – Retrieves the minimum value across the inspection points • Absolute Maximum – Retrieves the absolute maximum value across the inspection points • Absolute Minimum – Retrieves the absolute minimum value across the inspection points • Inspection Point – Retrieves the value for the point defined by the Specified Inspection Point Specified Inspection Point This attribute is exposed if Inspection Point is selected for the Result Value Option (otherwise this attribute is unused and should be zero). Enter a number between 1 and the maximum number of inspection points.

Damage Values • Per Wave (Solution) • All Wave Cases (Solutions) The damage per wave for each joint (worst case for each inspection point, shown on the brace and chord elements) can be displayed. For the Per Wave (Solution) result, the Spectrum or Wave Case Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Design Assessment number needs to be entered as additional input. For All Wave Cases (Solutions), results will be obtained and displayed for all, with minimum and maximum values shown.

Fatigue Assessment • Usage Factor • Life The Usage Factor or Life for each joint (worst case for each inspection point, shown on the brace and chord elements) can be displayed.

SCF Values • Brace Side • Chord Side The SCF factors for each joint for the chord and brace sides (worst case for each inspection point, shown on the brace and chord elements) can be displayed for the required component (Axial, In-Plane Bending, Out-of-Plane Bending).

Stress Histogram Results These results are only applicable to Time History analysis results. • Stress Range by Wave and Interval • Stress Range by Wave — All Intervals • Stress Range by Interval — All Waves • Occurrence by Wave and Interval • Occurrence by Wave — All Intervals • Occurrence by Interval — All Waves The stress range and occurrence of stress range data for each joint (worst case for each inspection point, shown on the brace and chord elements) can be displayed. In the cases where the result is for an individual wave (i.e. Transient analysis), the Wave Case number needs to be entered. This is equivalent to the row of the upstream solution in the Solution Selection table. In the cases where the result is for an individual interval, the Interval value needs to be entered. These results are only applicable to Spectral analysis results, when Stress Histogram Results Output is “Enabled”. • Occurrence by Interval • Occurrence — All Intervals • Occurrence Total • Stress Range by Interval • Stress Range — All Intervals 1204

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Predefined Assessment Types The stress range and occurrence of stress range data for each joint (worst case for each inspection point, shown on the brace and chord elements) can be displayed. In the case where the result is for an individual interval, the Interval value needs to be entered. When Stress Histogram Results Output is set to “By Transfer Function”, the following results are applicable: • Occurrence by Transfer Function and Interval • Occurrence by Transfer Function — All Intervals • Occurrence by Interval — All Transfer Functions The occurrence data for each joint (worst case for each inspection point, shown on the brace and chord elements) can be displayed for a given or all Transfer functions and a given or all Intervals. When Stress Histogram Results Output is set to “By Spectrum”, the following results are applicable: • Occurrence by Spectrum and Interval • Occurrence by Spectrum — All Intervals • Occurrence by Interval — All Spectrums The occurrence data for each joint (worst case for each inspection point, shown on the brace and chord elements) can be displayed for a given or all Spectrum(s) and a given or all Intervals.

Stress Range Results These results are only applicable to Stress History results; in addition, Stress Range Output must be set to either Peak Stress or Stress Range appropriately. • Signed Peak Stress • Signed Peak Stress – All Wave Cases • Peak Stress Utilization • Peak Stress Utilization – All Wave Cases • Stress Range • Stress Range – All Wave Cases • Stress Range Utilization • Stress Range Utilization – All Wave Cases The stress data for each joint (worst case for each inspection point, shown on the brace and chord elements) can be displayed. When a Wave Case is being specified, the Wave Case number is the case entered in the Deterministic analysis data. Utilization results are only available if an allowable stress has been entered. Non-utilization results are only available if a zero allowable stress has been entered.

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Using Design Assessment

Changing the Assessment Type or XML Definition File Contents If you change the Assessment Type of your Design Assessment system, or if you change the location or contents of the XML definition file, the Mechanical application will evaluate the existing Design Assessment objects in your project and modify those objects as indicated below. If no content changes are found in the XML definition file (even if the file location changes), or if only the Solve or Evaluate script locations change, no changes are made in the Design Assessment objects in the tree. If you change the Assessment Type of the Design Assessment system: From Solution Combination Only to BEAMCHECK All existing Attribute Group and DA Result objects will be refreshed based on certain criteria. From Solution Combination Only to FATJACK All Mechanical results inserted under the Solution object will be deleted and existing Attribute Group and DA Result objects will be refreshed based on certain criteria. From FATJACK to BEAMCHECK All existing Attribute Group and DA Result objects will be refreshed based on certain criteria. From FATJACK to Solution Combination Only All Attribute Group objects will be deleted and DA Result objects will be refreshed based on certain criteria. From BEAMCHECK to FATJACK All Mechanical results will be deleted and Attribute Group and DA Result objects will be refreshed based on certain criteria. From BEAMCHECK to Solution Combination Only All Attribute Group objects will be deleted and DA Result objects will be refreshed based on certain criteria.

Note The behavior described above also corresponds to the settings of the DAData and CombResults properties in the DAScripts section of the XML definition file. For BEAMCHECK, DAData=1 and CombResults=1; for FATJACK, DAData=1 and CombResults=0; for Solution Combination Only, DaData=0 and CombResults=1. So, for example, if you have the DAData and CombResults properties both set to 1 in a user defined XML file, and you change the DAData property to 0, the behavior would be that described in the From BEAMCHECK to Solution Combination Only entry above. If the contents of any Design Assessment XML definition file change, the Mechanical application refreshes the existing Design Assessment objects as follows: When the Group Type in use is not present in the file The affected Attribute Group or DA Result is initialized to default values. Default values are the values which you get when an Attribute Group or DA Result is inserted in the tree. When the Group Sub Type in use is not present in the file The affected Attribute Group or DA Result is initialized to default values. Default values are the values which you get when an Attribute Group or DA Result is inserted in the tree.

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Solution Selection When the Attribute IDs present for a Group Type and Sub Type combination in use are changed (IDs added or removed) The affected Attribute Group or DA Result is initialized to default values. Default values are the values which you get when an Attribute Group or DA Result is inserted in the tree. Group Type not in use is changed/added/removed No existing Design Assessment objects are affected. Group Sub Type not in use is changed/added/removed No existing Design Assessment objects are affected. Attribute IDs are changed/added/removed for a Group Type and Sub Type combination which is not in use No existing Design Assessment objects are affected. Validation/Default Value/Attribute Name/Geometry Application/Property type is changed Design Assessment object is modified as indicated.

Note For any above mentioned change, the state of the system becomes obsolete, forcing the user to solve again.

Solution Selection A Solution Selection object is automatically included as part of the Design Assessment environment. This object allows you to select upstream solutions to be used in a way similar to the standard Solution Combination object available in the Mechanical application. To use the Solution Selection object, the individual analysis systems should be connected in sequence on the Project Schematic (sharing the Engineering Data, Geometry and Model cells), with the Design Assessment system at the end of the chain. Depending upon the Assessment Type, various types of upstream systems are valid as shown in the table below. Assessment Type

Valid systems

Solution Combination Only

Static Structural, Modal, Harmonic Response, or Transient Structural

BEAMCHECK

Transient Structural or Static Structural

FATJACK

Transient Structural, Static Structural, or Harmonic Response

User Defined

Static Structural, Modal, Harmonic Response, Random Vibration, Response Spectrum, Explicit Dynamics, or Transient Structural

The Solution Selection Table When you click on the Solution Selection object in the tree, the Solution Selection table is displayed. To include systems in the Solution Selection table either for access to the results or inclusion in the solution combination, right click on the table and select Add. In the Environment Name column of the row that is added, click Choose…. and select the name of the system that you want to add to the table. For Static, Transient, Explicit, and Harmonic systems, you can specify that a set of results is returned for Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Design Assessment a particular system. (Other types of systems will only return a single result for each system at the indicated Time/Step, Frequency/Phase Angle, or Mode.)

Set the values in the columns to select the results that are returned for each solution. • Multiple Sets – Values are Enabled or Disabled. This column applies to any upstream solution that supports Multiple Set data, i.e. Static, Transient, Explicit Dynamics and Harmonic. – If Enabled, then the user can enter Start/End Times, or Min/Max Frequencies to define a result step/substep for combination (all result sets found within the boundaries of the defined step are used) or to use during the execution of their scripts. – If Disabled, then only the End Time and Max Frequency columns will be available in order to define a single result point to be used for combination (the result set defined is used for every calculated point in the combined result) or to use during the execution of the scripts. • Start Time (s) – Will define the start time of the step/substep used from the upstream solution. • End Time (s) – Will define the end time of the step/substep used from the upstream solution. • Step – The step number used from the upstream solution. Value can also be “Multiple” and “All”, in cases where the Start and End Times defined cover more than one step or the entire analysis from the upstream solution. • Min Frequency (s) – Will define the start frequency of the step/substep used from the upstream solution. • Max Frequency (s) – Will define the end frequency of the step/substep used from the upstream solution. The Step column in the solution selection table defaults to ‘All’ which means all steps from your upstream solution are available. All can be specified by entering ‘0’ in the Step column. Otherwise this column can take any integer value that lies within the step boundaries to define a single step. If you define a start or end time that is outside the boundaries of one step, then the Step column will say Multiple. Steps are inclusive of their Start/End Times or Min/Max Frequencies. During combination, the data from all result points within the steps/substeps defined are linearly combined to produce a result containing multiple sets. Therefore the limits of the combined result will be defined by the smallest and greatest values (Start/End Time or Min/Max Frequency) found within the Solution Selection table.

Results Availability The Results Availability field in the Details panel for the Design Assessment system Solution object allows you to specify which Mechanical results will be available to the Design Assessment system. If Results Availability is set to Filter Combination Results and different upstream system types are selected, only results that are valid for all selected systems can be inserted under the Solution object.

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Solution Selection However, if you set the Results Availability field to Allow all Available Results, you can add any results valid for any of the selected systems to the Solution object. In this case, results that are inserted will be combined for those systems for which they are valid. You can set the default value for the Results Availability field in the Mechanical Options. If Results Availability is set to Filter Combination Results, and additional upstream systems are selected which cause a result type to be invalid, then its state will change accordingly and a solution will not be possible.

Note • When used in a solution combination based result, it may not be correct to combine the results. Any combined results are formed by linear combination only. • The available systems in the drop down list are not constrained depending upon the Assessment Type. • The Results Availability setting will only appear under the Design Assessment Solution object in the tree if the

tag within the XML that is being used by the Design Assessment system is set to 1. Otherwise it has no function. • User defined results containing complex expressions are supported through the use of DA Results. In addition, you can access results from various environments, using python scripts to combine results with highly complex, user defined mathematical functions (see CreateSolutionResult in the Solution class).

Solution Combination Behavior The Solution Selection object differs in several ways from a standard Solution Combination object: • There is an ability to add extra columns to the worksheet using the XML configuration file. Each row in the table can be used to enter additional data that can be passed out to the processing script. These values can be obtained using the Design Assessment API. • Results are added to the Solution object in the Design Assessment system, not directly under the Solution Selection object. • The Solution Selection object can be configured such that select results from multiple upstream systems are available for use in post processing scripts, but the display of combined results is suppressed. For the FATJACK Assessment Type, or when CombResults = 0 in a user defined XML file, Solution Selection will make the results of the selected solutions available for external processing, but no solution combination is done, and no Mechanical results are available. • Appropriate columns are enabled to access appropriate result sets defined by start time, end time, step, minimum frequency, maximum frequency, phase angle, and mode, based on the upstream system. • Upstream results systems can be accessed via the python scripts using the Selection class. Where times or frequencies overlap, data will be combined. However, where these values are unique to an upstream solution, the data will be the equivalent to the result point held in the upstream solution.

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Using Design Assessment The following tables and charts illustrate how the combination takes place. Here is an example of solutions entered in the Solution Combination table:

The individual uncombined results are:

The combined results would be as follows. Notice here that the solution with Multiple Sets Disabled is a single result point and therefore combined over the entire result.

The Effective Result for the deformation values of Node X in the combined result would be:

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Using the Attribute Group Object

The combined plot, where the Combination line illustrates the combined values of Node X in Solutions 1 to 4 at these time points, would be:

Using the Attribute Group Object Attribute Group objects allow the Mechanical application to collect inputs. They are available in Predefined Assessment Types such as BEAMST and FATJACK, or can also be configured in the XML definition file of a User Defined Type. After you have opened the project in the Mechanical application, insert an Attribute Group by one of the following methods: 1. Right click on the Design Assessment object and select Insert > Attribute Group or Click on the Design Assessment object, then click on the Attribute Group button in the toolbar. An Attribute Group object will be added to the analysis.

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Using Design Assessment 2. Click on the Attribute Group and then set it up by selecting the appropriate AttributeGroupType and AttributeGroupSubtype. This will display the attributes for that group subtype. 3. Enter the attribute values that you wish to pass out to the postprocessing script defined in the XML definition file, along with any associated geometry information.

Note Numerical attributes within an attribute group can be parameterized.

Developing and Debugging Design Assessment Scripts The scripting environment used in Design Assessment is the same as that used in the Workbench and is based on IronPython, which is well integrated into the rest of the .NET Framework (on Windows) and Mono CLR (on Linux). For more details see the Workbench Scripting documentation.

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Using the DA Result Object With the help of a development environment, such as Microsoft® Visual Studio®, Python scripts can be developed and “debugged”. To debug a script, open its text file in your development environment and attach the debugger to the AnsysWBU.exe process of interest. Be sure to specify managed code mode. You will then be able to control the execution of your script, stepping along and reviewing the values obtained.

Using the DA Result Object DA Results Objects allow you to specify what results to calculate and how to display them. You can add DA Result objects to the analysis system for the BEAMCHECK, FATJACK or Solution Combination assessment types, and for any custom scripts you create. Define a DA Result object in a Design Assessment system as follows: 1. Insert a DA Result object using one of the following methods. • Right click on the Solution object under Design Assessment and select Insert > DA Result, or • Click on the Solution object, then click on the DA Result button in the toolbar. Click on the newly added DA Result object to setup the fields in the Details panel. 2. Set the Scoping Method for the DA Result. • If you choose Geometry Selection, Geometry defaults to All Bodies; or you can select the part of the geometry for which you want to see results and click Apply. • If you choose Named Selection, select a defined Named Selection from the drop down list. 3. Select the desired Result Type and Result Subtype from the drop down lists. 4. Set By to Substep Value or Result Set. • If you choose Result Set, enter the result Set Number that you want to observe. • If you choose Substep Value, enter the Substep Value. Substep Value is equivalent to the Result Time/Result Frequency on a normal Result Object, and as such if you enter ‘0’ in the user interface you will automatically receive the ‘Last’ result point. Otherwise you can enter any double value that is within the boundaries of your result. 5. Set the Entry Value for each attribute in the DA Result object to return the Results of interest to you. 6. Right click on the DA Result object and select Solve. The results of the post processing script are displayed in the Results section of the Details panel, and the resulting contour is shown in the Graphics window if applicable for that result type.

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Using Design Assessment

The Design Assessment XML Definition File The Design Assessment system is driven in part by an XML definition file (referred to as the XML definition file). This file can be user defined or provided by ANSYS or a third party. This section defines the format of the XML definition file. The XML definition file is split into four parts to define the following: • Available Attributes • Attribute Groups • Scripts • Result Availability For each Design Assessment system, a copy will be made of the selected XML definition file and associated with that Design Assessment system to define the visibility of the tree objects. The entries in the tree objects will be saved with the Mechanical project database file; this includes the actual script used for the assessment. The overview of the file format is shown below.

definition of attributes for re-use throughout the attribute groups.

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The Design Assessment XML Definition File

grouping of attributes; used to define the available options in the attribute groups objects analysis script language & contents; used to define a script covering how the design assessment will be performed and a script used to obtain results definition of the available results and the available options in the results object.

Note For all sections of the XML definition file, all values entered as part of a list in a tag must be separated by commas only (no spaces); for example in the following tag,

0.5,10, there should not be any space between the values 0.5 and 10.

Attributes Format Within the Attributes section there are a number of options to define the name and type of attribute (for example, whether it’s a double, integer, drop-down list, text, etc.), and what it applies to (for example, can it be applied to selectable geometry or loadcases, and if geometry, is it vertex, lines, surfaces or solids). Depending upon the type, default values and validation ranges can be set. Attributes of int and double types can be parameterized.

attr name type keyword <Application PropType=»string»>selection keyword validation data default value display units keyword

The attribute is defined in the Details panel with 4 rows:

If Scoping Method is set to Named Selection, the fourth row will contain a drop-down of all defined named selections that contain geometric entities of the type specified in the attribute definition.

The Attributes tag properties should be set as follows: Property

Value

Meaning

ObjId

enter an integer

Number identifying this attribute collection

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Using Design Assessment Property

Value

Meaning

Type

CAERepBase

Specifies that the file is in ANSYS intermediate file format

Ver

enter an integer

Version of the Attributes object definition; this should be set to 2

The DAAttribute tag properties should be set as follows: Property

Value

Meaning

ObjId

enter an integer

Unique number identifying this DAAttribute, suggest starting at a fixed number (e.g. 100) to avoid conflict with other objects

Type

DAAttribute

Signifies that the contents of the DAAttribute tag define an attribute

Ver

enter an integer

Version of the DAAtribute object definition; this should be set to 2

The following tags can be included as children of a DAAttribute tag (note that each tag must have a property PropType=”string” or PropType=”vector<string>” (the latter if entering more than a single value in the tag contents). Property

Value

Meaning

AttributeName

enter a string

Displayed name of the attribute

AttributeType, with following values of type keyword allowed:

Int

Integer entry only

Double

Double precision entry only

Text

Text entry only

DropDown

Drop down list selection

Browse

Text based, but includes browse to a file button

None

Only Geometry Selection required, hides Value Cell

Application, with following values Vertices of selection keyword allowed: Lines

Validation, with following values of validation data allowed:

Enables Geometric selection of vertices only Enables Geometric selection of line bodies only

Surfaces

Enables Geometric selection of surface bodies only

Solids

Enables Geometric selection of solid bodies only

Geometry

Enables Geometric selection of lines, surfaces and solids

All

Hides Geometry Selection cell, applies to the whole analysis

Two comma separated numbers defining a min and max

For Int or Double type keywords

Multiple comma separated strings For DropDown type keywords defining the available entries 1216

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The Design Assessment XML Definition File Property

Default, with following values of default value allowed:

DisplayUnits, with following values of display units keywords allowed: (Only used if version number of DAAttribute > 2 and AttributeType is Double) When a display unit is defined the value will automatically scale depending on the defined unit system for the Analysis and for the unit system used to view

Value

Meaning

A single number to define the maximum length of the string

For the Text or Browse type keywords

Default value in SI units; if default For Int or Double type keywords is within the valid range, when it’s created the object state will be checked, otherwise “?” String; used to set the default entry in the drop-down

For DropDown type keywords

Default text string

For the Text or Browse type keywords

No Units

No units are associated with the value (default if field is not defined)

Stress

Values are treated as stress

Distance

Values are treated as distance

Strain

Values are treated as strain

Force

Values are treated as force

Moment

Values are treated as moment, i.e. force x distance

Rotation

Values are treated as rotation

Angular Acceleration

Values are treated as angular acceleration, i.e. rotation / time2

Angular Velocity

Values are treated as angular velocity, i.e. rotation / time

Velocity

Values are treated as velocity, i.e. distance / time

Acceleration

Values are treated as acceleration, i.e. distance / time2

Temperature

Values are treated as temperature

Pressure

Values are treated as pressure, i.e. force / distance2

Voltage

Values are treated as voltage

Energy

Values are treated as energy

Volume

Values are treated as volume, i.e. distance3

Area

Values are treated as area, i.e. distance2

Current

Values are treated as current

Heat Rate

Values are treated as heat rate

Current Density

Values are treated as current density

Power

Values are treated as power

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Using Design Assessment Property

Value

Meaning

Heat Generation

Values are treated as heat generation

Magnetic Flux

Values are treated as magnetic flux

Attribute Groups Format The AttributeGroups tag contains DAAttributeGroup tags that provide a means for the user to select the groups of attributes shown in the Details panel when an Attributes Group tree object is selected. A maximum of 10 attributes can be grouped per attribute group object. Attribute group objects automatically sort themselves by drop downs of available types and subtypes.

Group Type Group Subtype «>list of attribute numbers

The group is defined in the Details panel with 3 standard rows and then up to 10 attributes:

The AttributeGroups tag properties should be set as follows: Property

Value

Meaning

ObjId

enter an integer

Number identifying this attribute group collection

Type

CAERepBase

Specifies that the file is in ANSYS intermediate file format

Ver

enter an integer

Version of the AttributeGroups object definition; this should be set to 2

The DAAttributeGroup tag properties should be set as follows: Property

Value

Meaning

ObjId

enter an integer

Unique number identifying this DAAttributeGroup, suggest starting at fixed number (e.g. 500) to avoid conflict with other objects

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The Design Assessment XML Definition File Property

Value

Meaning

Type

DAAttributeGroup

Signifies that the contents of the DAAttributeGroup tag define an attribute group

Ver

enter an integer

Version of the DAAttributeGroup object definition; this should be set to 2

The following tags can be included as children of a DAAttributeGroup tag: Property

Value

Meaning

GroupType

enter a string

Type of this attribute group

GroupSubtype

enter a string

Subtype of this attribute group

AttributeIDs

enter a comma separated list of attribute ID numbers

Attributes that will be displayed for this attribute group

The PropType property of the GroupType and GroupSubtype tags must be set to string, and the PropType property of the AttributeIDs tags must be set to vector<unsigned int>.

Script Format This section defines the location for the Design Assessment post processing scripts and also defines what values can be accessed in this Design Assessment system. The scripts are to be written using the Python scripting language. There are three Design Assessment specific system environment variables that can be used when specifying script paths: DAPROGFILES Default: C:\Program Files DANSYSDIR Default: C:\Program Files\ANSYS Inc\v150 DAUSERFILES The Workbench project user_files subfolder The Solve tag defines the location of the script that will be run upon pressing the solve button within the Mechanical application. The Evaluate tag defines the location of the script that will be run when evaluating the DAResult objects. The Evaluate script will be run by default after the solve script when solve has been selected. This separation enables the ability for any intensive processing to be performed and saved to files during the solve stage and then results extraction and presentation to be scripted during the evaluation stage. Alternatively, you may want all the processing performed during the evaluate script and enter None in the Solve Script section. Additional tags allow you to: • permit or prevent the inclusion of Design Assessment Attribute Groups and Results in the tree for the associated Design Assessment system • permit or prevent the availability of solution combination results in the associated Design Assessment system • add additional columns to the Solution Selection Worksheet Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Design Assessment • define which upstream solution types are permitted in the Solution Selection Worksheet

<Solve PropType=»string»>»c:\mysolve.py» <Evaluate PropType=»string»>»c:\myevaluate.py» 1 1 Extra 1,Extra 2,Extra 3 1,2,3,4,5,6,7 lt;/DAScripts>

The DAScripts tag properties should be set as follows: Property

Value

Meaning

ObjId

enter an integer

Number identifying this script set

Type

DAScripts

Signifies that the contents of the DAScripts tag define solve and evaluate postprocessing scripts

Ver

enter an integer

Version of the DAScripts tag; this should be set to 2

The following tags can be included as children of a DAScripts tag: Property

Value

Meaning

Solve

enter a string

Path to the file called during the solution; a relative path can be entered. A relative path will be relative to {install}\aisol\bin\{platform}, so for example, ..\..\..\My_Solve.py would need to be located in the same folder as the installation. Standard environment variables or one of the Design Assessment specific environment variables may be used in the path (enclosed in percent signs). For example: %TEMP%\My_solve.py %DAPROGFILES%\My_solve.py If no solve script is required, the keyword None can be entered.

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The Design Assessment XML Definition File Property

Value

Meaning

Evaluate

enter a string

Path to the file called during the evaluate. As per the Solve string, this can be relative or use standard environment variables or the Design Assessment specific environment variables.

DAData

enter either 1 or 0

Set to 0 to prevent any DA Data (Attribute Groups or DA Results) from being added to the project, or 1 to allow them

CombResults

enter either 1 or 0

Set to 0 to prevent Mechanical Results objects from being added to the Design Assessment Solution, or 1 to allow them

CombExtra

enter a comma separated list of strings

Enter a string for each extra column heading that you want to appear in the Solution Selection Worksheet.

CombTypes

enter a comma separated list of positive numbers between 1 and 7

Each of the numbers represents a system type. Only system types in this list will be permitted to be selected in the Solution Selections table. The numbers correspond to the systems as follows: 1: Static Structural 2: Transient Structural 3: Explicit Dynamics 4: Modal 5: Harmonic Response 6: Random Vibration 7: Response Spectrum If CombTypes is not defined, there will be no restrictions applied.

The PropType property of the Solve and Evaluate tags must be set to string, The PropType property of the DAData and CombResults tags must be set to int, and the PropType property of the CombExtra tag must be set to vector<string> and the PropType property of the CombTypes tag must be set to vector<unsigned int>.

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Using Design Assessment

Results Format The DA Results format defines the available DA Results tree objects. A maximum of 10 attributes can be included per DA Result object; for example to define direction components. For attributes applied to results objects, the application entry is ignored. DA Result objects automatically sort themselves by drop downs of available types and subtypes. Each DA Result object also contains information on how it should display results; this can either be set in this XML definition file or programmatically in the python solve or evaluate scripts. Minimum and maximum values are also reported and can be parametrized. Probe labels can be added to the graphic to identify specific results, or the minimum and maximum locations.

Group Type Group Subtype «>list of attribute numbers display type keyword display style keyword display units keyword

The result is defined in the Details panel with standard rows and then up to 10 attributes:

Note that if the Display Style of a result is anything other than scalar, a «Components» field is shown in the Definitions section. The Results tag properties should be set as follows: Property

Value

Meaning

ObjId

enter an integer

Number identifying this attribute group collection

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The Design Assessment XML Definition File Property

Value

Meaning

Type

CAERepBase

Specifies that the file is in ANSYS intermediate file format

Ver

enter an integer

Version of the Results definition section; this should be set to 2

The DAResult tag properties should be set as follows: Property

Value

Meaning

ObjId

enter an integer

Unique number identifying this DA Result; suggest starting at a fixed number (e.g. 1000) to avoid conflict with other objects

Type

DAResult

Signifies that the contents of the DAResult tag defines a result group

Ver

enter an integer

Version of the DA Result object definition; this should be set to 3

The following tags can be included as children of a DAResult tag: Property

Value

Meaning

GroupType

enter a string

Type of this DA Result object

GroupSubtype

enter a string

Subtype of this DA Result object

AttributeIDs

enter a comma separated list of attribute ID numbers

Attributes that will be displayed for this DA Result object

DisplayType, with following values of display type keywords allowed:

Element

Values per element are expected

Nodal

Values per node are expected.

ElementNodal

Values per node of each element are expected

Scalar

A single number is expected for each element / node depending upon the DisplayType set (default if field is not defined)

Vector

X, Y and Z component values are expected for each element / node depending upon the DisplayType

DisplayStyle, with following values of display style keywords allowed: (Only used if version number of DAResult > 2)

An additional drop down will be provided to choose between X, Y, Z, Resultant and Vector Display The Resultant, R, is determined by

= √ Tensor

 +   + 

X, Y, Z, XY, YZ and XZ component values are expected for each element / node de-

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1223

Using Design Assessment Property

Value

Meaning pending upon the DisplayType An additional drop down will be provided to choose between X, Y, Z, XY, YZ and XZ, Maximum Principal, Middle Principal, Minimum Principal, Intensity, Equivalent, Vector Principal, and Maximum Shear

DisplayUnits, with following values of display units keywords allowed: (Only used if version number of DAResult > 2) When a display unit is defined the result will automatically scale depending on the given unit system

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StrainTensor

As Tensor, but without the Maximum Shear option

No Units

No units are associated with the result (default if field is not defined)

Stress

Results are treated as stress

Distance

Results are treated as distance

Strain

Results are treated as strain

Force

Results are treated as force

Moment

Results are treated as moment, i.e. force x distance

Rotation

Results are treated as rotation

Angular Acceleration

Results are treated as angular acceleration, i.e. rotation / time2

Angular Velocity

Results are treated as angular velocity, i.e. rotation / time

Velocity

Results are treated as velocity, i.e. distance / time

Acceleration

Results are treated as acceleration, i.e. distance / time2

Temperature

Results are treated as temperature

Pressure

Results are treated as pressure, i.e. force / distance2

Voltage

Results are treated as voltage

Energy

Results are treated as energy

Volume

Results are treated as volume, i.e. distance3

Area

Results are treated as area, i.e. distance2

Current

Results are treated as current

Heat Rate

Results are treated as heat rate

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Design Assessment API Reference Property

Value

Meaning

Current Density

Results are treated as current density

Power

Results are treated as power

Heat Generation

Results are treated as heat generation

Magnetic Flux

Results are treated as magnetic flux

The DisplayType, DisplayStyle and Display unit can all be over-ridden or set within the python script if desired. However, DisplayStyle needs to be set here to enable the addition of the drop-down to choose the component and automatic calculation of additional results (e.g. Resultant, Maximum Principal, etc.) in the cases of vector or tensor display. See the DAResult class in the API for details on how to set these programmatically. The PropType property of the GroupType, GroupSubtype, and DisplayType tags must be set to string, and the PropType property of the AttributeIDs tags must be set to vector<unsigned int>.

Design Assessment API Reference These guidelines describe the Design Assessment API. Included with the standard ANSYS Workbench installation is the IronPython scripting environment that allows a Python script to be run. Within Design Assessment scripts can be run upon Solve and Evaluate. These Python based scripts have a DesignAssessment object defined as an entry point to access to the API functions to enable data to be processed either directly in python, or externally by calling 3rd party programs. The following API classes are available: DesignAssessment class Helper class MeshData class DAElement class DANode class SectionData class AttributeGroup class Attribute class SolutionSelection class Solution class SolutionResult class DAResult class DAResultSet class The API is structured as shown in this diagram:

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Using Design Assessment

Every effort is made to ensure compatibility of the API across versions. However, there are occasions where functions or properties need to be modified. In these scenarios, the existing function will be deprecated, i.e. it will become undocumented. Any data output via the print command will be added to the appropriate script output file which can be reviewed via the Solution Information object. If a deprecated function is called a message will be added to the appropriate script output file with a suggested alternative methodology. These can be viewed via the Solution Information object. This inclusion of the message in the file can be controlled by the OutputDeprecatedWarnings function in the DesignAssessment class. Additional text output from your script can be included in a file that is displayed using the Solver Output option (see Helper class, ReplaceSolverOutputFile). Undocumented functions (including those recently deprecated) may be removed or altered in subsequent releases if it becomes impractical to maintain a backwards compatible interface, so effort should be made to update any calls to deprecated functions. Functions may not work on previous releases; therefore, all users should use the same release of Workbench to ensure compatibility.

API Change Log for R14.5 No functions were deprecated or modified with this release. Newly added functions are not detailed here, but were mainly contained within the Solution class.

API Change Log for R14.0 Release 14 represents the first release after the initial version. In response to feedback, we have made a number of changes of functions to properties where appropriate, hence there are an unusually high number of deprecated functions. These changes are tabulated below, grouped by class name. The tables do not include newly added functions. Design Assessment Class: 1226

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Design Assessment API Reference Method/Property

Description of Change

getHelper()

Changed to property Helper, old code: DesignAssessment.getHelper(), new code DesignAssessment.Helper

GeometryMeshData()

Changed to property MeshData, old code: DesignAssessment.GeometryMeshData(), new code DesignAssessment.MeshData

Selections()

Changed name to SolutionSelections() to be consistent with the Mechanical application

Selection(int Index)

Duplication of python functionality. Old code DesignAssessment.SolutionSelection(0), new code MyArray = DesignAssessment.SolutionSelections() then MyArray[0] (NB, using the shortcut DesignAssessment.SolutionSelections()[index] in a loop is less efficient than assigning it to an array within python)

ResultGroups()

Changed name to DAResults() to be consistent with the Mechanical application

ResultGroup(int Index)

Duplication of python functionality. Old code DesignAssessment.DAResult(0), new code MyArray = DesignAssessment.DAResults() then MyArray[0] (NB, using the shortcut DesignAssessment.DAResults()[index] in a loop is less efficient than assigning it to an array within python)

NoOfAttributeGroups()

Changed to property AttributeGroupCount, old code: DesignAssessment.NoOfAttributeGroups(), new code DesignAssessment.AttributeGroupCount

NoOfSelections()

Changed to property SolutionSelectionCount, old code: DesignAssessment.NoOfSelections(), new code DesignAssessment.SolutionSelectionCount

NoOfResultGroups()

Changed to property DAResultCount, old code: DesignAssessment. NoOfResultGroups(), new code DesignAssessment.DAResultCount

ProjectName()

Changed to property ProjectTitle, old code: DesignAssessment. ProjectName(), new code DesignAssessment.ProjectTitle

AttributeGroup(int Index)

Duplication of python functionality. Old code DesignAssessment.AttributeGroup(0), new code MyArray = DesignAssessment.AttributeGroups() then MyArray[0] (NB, using the shortcut DesignAssessment.AttributeGroups()[index] in a loop is less efficient than assigning it to an array within python)

Helper Class: A number of functions related to an internal file, the CAERep, were previously documented in error. These have been removed from the documentation; it is not recommended that these are used as the file structure is subject to change. Function/Property

Description of Change

getUnits()

Replaced by property Units in the DesignAssessment class, for the units set for the Design Assessment System and also the property Units in the Solution class for the units system used in upstream solution.

getSolverOut()

Changed to property SolverOutputFilePath, old code: Helper.getSolverOut(), new code Helper.SolverOutputFilePath

getOutputFile()

Changed to property SystemDirectory, old code: Helper.getOutputFile(), new code Helper.SystemDirectory

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Using Design Assessment Function/Property

Description of Change

getGeometryPath ()

Changed to property GeometryPath, old code: Helper. getGeometryPath (), new code Helper.GeometryPath

getResultPath ()

Changed to property ResultPath, old code: Helper.getResultPath(), new code Helper.ResultPath

getSystemDirectory ()

Changed to property SystemDirectory, old code: Helper.getSystemDirectory(), new code Helper.SystemDirectory

getLogFile()

Removed as the log file can be displayed via Solution Information and its contents can be added to via the standard python print function

WriteToLog ()

Removed as the log file contents can be added to via the standard python print function

MeshData Class (previously named GeometryMeshData): A number of functions related to an internal reference, the TopologyID, were previously documented in error. These have been removed from the documentation. Method/Property

Description of Change

NoOfNodes()

Changed to property NodeCount, old code: MeshData. NoOfNodes(), new code MeshData.NodeCount

NoOfElements()

Changed to property ElementCount, old code: MeshData.NoOfElements(), new code MeshData.ElementCount

ElementbyID(int ID)

Corrected capitalization, old code: MeshData.ElementbyID(Id), new code MeshData.ElementById(Id)

NodebyID(int ID)

Corrected capitalization, old code: MeshData.NodebyID(Id), new code MeshData.NodeById(Id)

getConnectedElementIDs (int ID)

Removed as incorrectly located and duplicated functionality; the method should be the responsibility of the Node object, old code: MeshData.getConnectedElementIDs(Id), new code MeshData.NodeById(Id).ConnectedElementIds()

getConnectedElements (int ID)

Removed as incorrectly located and duplicated functionality; the method should be the responsibility of the Node object, old code: MeshData.getConnectedElementIDs(ID), new code MeshData.NodeById(Id).ConnectedElements()

getElementsByID(int[] ID)

Consistency issue, old code: MeshData.getElementsByID (ID[]), new code MeshData.ElementsByIds(ID[])

Element(int Index)

Duplication of python functionality. Old code MeshData.Element(0), new code MyArray = MeshData.Elements() then MyArray[0] (NB, using the shortcut MeshData.Elements()[index] in a loop is less efficient than assigning it to an array within python)

Node(int Index)

Duplication of python functionality. Old code MeshData.Node(0), new code MyArray = MeshData.Nodes() then MyArray[0] (NB, using the shortcut MeshData.Nodes()[index] in a loop is less efficient than assigning it to an array within python)

DAElement Class: The function TopologyID() related to an internal reference was previously documented in error. This has been removed from the documentation.

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Design Assessment API Reference Method/Property

Description of Change

Type()

Replaced with property Description, this provides a text description of the element, rather than an internal number which was subject to change, old code: DAElement.Type(), new code DAElement.Description

SectionData()

Changed to property CrossSectionData, old code: DAElement.SectionData(), new code DAElement.CrossSectionData

getNodeIDs()

Consistency issue, old code: DAElement.getNodeIDs(), new code DAElement.NodeIds()

ID()

Changed to property Id, old code: DAElement.ID(), new code DAElement.Id

NoOfConnectedNodes()

Changed to property NodeCount, old code: DAElement.NoOfConnectedNodes(), new code DAElement.NodeCount

DANode Class: Method/Property

Description of Change

ID()

Changed to property Id, old code: DANode.ID(), new code DANode.Id

x()

Changed to property X, old code: DANode.x(), new code DANode.X

y()

Changed to property Y, old code: DANode.y(), new code DANode.Y

z()

Changed to property Z, old code: DANode.z(), new code DANode.Z

NoOfConnectedElements()

Changed to property ConnectedElementCount, old code: DANode.NoOfConnectedElements(), new code DANode.ConnectedElementCount

ConnectedElementIDs()

Corrected capitalization, old code: DANode.ConnectedElementIDs(Id), new code DANode.ConnectedElementIds(Id)

SectionData Class: Method/Property

Description of Change

Type()

Replaced with property Description, this provides a text description of the element, rather than an internal number which was subject to change, old code: SectionData.Type(), new code SectionData.Description

Diameter()

Changed to property TubeDiameter, old code: SectionData.Diameter(), new code SectionData.TubeDiameter

Thickness()

Changed to property TubeThickness, old code: SectionData.Thickness(), new code SectionData.TubeThickness

WebThickness()

Changed to property BeamWebThickness, old code: SectionData.WebThickness(), new code SectionData.BeamWebThickness

FlangeThickness()

Changed to property BeamFlangeThickness, old code: SectionData.FlangeThickness(), new code SectionData.BeamFlangeThickness

FilletRadii()

Changed to property BeamFilletRadii, old code: SectionData.FilletRadii(), new code SectionData.BeamFilletRadii

Height()

Changed to property BeamHeight, old code: SectionData.Height(), new code SectionData.BeamHeight

Width()

Changed to property BeamWidth, old code: SectionData.Width(), new code SectionData.BeamWidth Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Design Assessment AttributeGroup Class: Method/Property

Description of Change

NoOfAttributes()

Changed to property AttributeCount, old code: AttributeGroup.NoOfAttributes(), new code AttributeGroup.AttributeCount

Name()

Changed to property TreeName, old code: AttributeGroup.Name(), new code AttributeGroup.TreeName

Type()

Changed to property XmlType, old code: AttributeGroup.Type(), new code AttributeGroup.XmlType

SubType()

Changed to property XmlSubType, old code: AttributeGroup.SubType(), new code AttributeGroup.XmlSubType

Attribute Class: Method/Property

Description of Change

Name()

Changed to property AttributeName, old code: Attribute.Name(), new code Attribute.AttributeName

Value()

Replaced with the properties ValueAsInt, ValueAsDouble, ValueAsString in order to simplify the interface, old code: ValueObj = Attribute.Value() then ValueObj.GetAsInt(), new code: Attribute.ValueAsInt

getNoOfSelectedElements()

Changed to property SelectedElementCount, old code: Attribute.getNoOfSelectedElements(), new code Attribute.SelectedElementCount

getSelectedElements()

Consistency issue, old code: Attribute.getSelectedElements(), new code Attribute.SelectedElements()

getNoOfSelectedNodes()

Changed to property SelectedNodeCount, old code: Attribute.getNoOfSelectedNodes(), new code Attribute.SelectedNodeCount

getSelectedNodes()

Consistency issue, old code: Attribute.getSelectedNodes(), new code Attribute.SelectedNodes()

SolutionSelection Class (previously named Selection): Method/Property

Description of Change

NoOfSolutions()

Changed to property SolutionCount, old code: Selection.NoOfSolutions(), new code SolutionSelection.SolutionCount

Solution(int index)

Replaced with method SolutionByRow(int Row), Row is 1 based. Old code: Selection.Solution(0), new code SolutionSelection.SolutionByRow(1)

Solution Class: Method/Property

Description of Change

NoOfAdditionalSolutionData()

Changed to property AdditionalSolutionDataCount, old code: Solution.NoOfAdditionalSolutionData(), new code Solution.AdditionalSolutionDataCount

EnvironmentName()

Changed to property Id, old code: Solution.EnvironmentName(), new code Solution.Id

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Design Assessment API Reference Method/Property

Description of Change

getResult()

This method and the object it returned have been removed and the objects functions replaced with properties within the Solution Class. Old code: Solution.getResult().ResultFilePath(), new code: Solution.ResultFilePath

AdditionalSolutionData(int Index)

Replaced with method AdditionalSolutionDataByColumn (int Col), Col is 1 based. Old code: Solution. AdditionalSolutionData(0), new code Solution.AdditionalSolutionDataByColumn(1)

SolutionResult Class: Method/Property

Description of Change

ResultFilePath()

Function moved to SolutionClass. Old code: Solution.getResult().ResultFilePath(), new code: Solution.ResultFilePath

DAResult Class (previously named ResultGroup): Method/Property

Description of Change

Name()

Changed to property TreeName, old code: ResultGroup.Name(), new code DAResult.TreeName

Type()

Changed to property XmlType, old code: ResultGroup.Type(), new code DAResult.XmlType

AddStepResult()

Renamed to AddDAResultSet, old code: ResultGroup.AddStepResult(), new code DAResult.AddDAResultSet()

AddStepResult(Result myResult)

Function has been removed, use AddDAResultSet to create the DAResultSet object then define values within that object.

StepResult()

Renamed to DAResultSets(), old code: ResultGroup.StepResult(), new code DAResult.DAResultSets()

StepResult(int index)

Renamed to DAResultSet(), old code: ResultGroup.StepResult(index), new code DAResult.DAResultSet(SetNumber). Note: SetNumber is 1 based.

NoOfAttributes()

Changed to property AttributeCount, old code: ResultGroup.NoOfAttributes(), new code DAResult. AttributeCount

DAResultSet Class (previously named Result): Method/Property

Description of Change

AddElementResultValue(ValueStructureClass newElementResultValue)

Modified so that it’s easier to create sets of result values. Now element result values can be directly defined using SetElementalValue. Old code Result.AddElementValue(ValueStructure), new code: DAResultSet.SetElementalValue(ElementID, Component, Value)

ValueStructureClass AddElementResultValue()

The ValueStructure class has been deprecated as the result values can be accessed directly. Values are also now added with a given ElementID, so numerous entries need not be made. Old code ValueStructure = Result.AddElementValue() then ValueStructure.setValue(Value), new code: DAResultSet.SetElementalValue(ElementID, Component, Value)

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Using Design Assessment Method/Property

Description of Change

ValueStructureClass[] ElementResultValues()

The ValueStructure class has been deprecated as the result values can be accessed directly for the given element. It is no longer possible to get all the values out as an Array, but values can be obtained via GetElementalValue(ElementID, Component) instead.

ValueStructureClass ElementResultValue(int index)

The ValueStructure class has been deprecated as the result values can be accessed directly for the given element. Values are also now added with a given ElementID. Old code ValueStructure = Result. ElementResultValue(Index) then Value = ValueStructure.GetAsDouble(), new code: Value = DAResultSet.GetElementalValue(ElementID, Component)

ValueStructure Class: This class has been deprecated; all functionality is now redundant as the values can either be obtained or set directly.

DesignAssessment class This class is the parent class of all Design Assessment API objects that can be called from the python scripts. It is a global variable that can be accessed from anywhere in your script. Table 95: Members Name

Type

Description

Helper

Helper class

See Helper class description for available properties and methods

Units

string

Returns the solver units defined by the user in the analysis settings, represented as a string: MKS: i.e. Metric (m, Kg, N, s, V, A) UMKS: i.e. Metric (µm, Kg, µN, s, mV, mA) CGS: i.e. Metric (cm, g, dyne, s, V, A) NMM: i.e. Metric (mm, Kg, N, s, mV, mA) LBFT: i.e. US Customary (ft, lbm, lbf, s, V, A) LBIN: i.e. US Customary (in, lbm, lbf, s, V, A)

MeshData

MeshData class

See MeshData class description for available properties and methods

AttributeGroups()

AttributeGroup[] class

Array of AttributeGroup objects

AttributeGroups(string TreeName)

AttributeGroup[] class

Array of AttributeGroup objects with the given TreeName filtered from the available AttributeGroups

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Design Assessment API Reference Name

Type

Description

AttributeGroups(string Type, string SubType)

AttributeGroup[] class

Array of AttributeGroup objects with the given Type and SubType filtered from the available AttributeGroups

SolutionSelections()

SolutionSelection[] class

Array of SolutionSelection class objects

DAResults()

DAResult[] class

Array of DAResult objects

DAResults(string TreeName)

DAResult[] class

Array of DAResult objects with the given TreeName filtered from the available DAResults

DAResults(string Type, string SubType)

DAResult[] class

Array of DAResult objects with the given Type and SubType filtered from the available DAResults

AttributeGroupCount

int

A count of the number of AttributeGroup objects

SolutionSelectionCount

int

A count of the number of SolutionSelection objects

DAResultCount

int

A count of the number of DAResult objects

ProjectTitle

string

The title of the project

OutputDeprecatedWarnings(bool ShowWarnings)

void

Sets the verbosity of the warnings related to deprecated properties/methods: False – for no output True – for full output for each call Warnings are presented as text output to the solve or evaluate debug logs. By default only a summary is shown; the user can then decide to add this function to their script to display them all, or display none.

Example Usage The following example can be used as a basis of either the solve or evaluate script. def runClassDemo_DesignAssessment(): DA = DesignAssessment #just to save typing. #To know full details of deprecated functions. DA.OutputDeprecatedWarnings(True) #Get the helper object HelperObject = DA.Helper #Output units string, e.g. MKS print DA.Units # Get the MeshData object MeshDataObject = DA.MeshData print DA.ProjectTitle #Attribute Groups: #Obtain an array of all attribute group objects. AllAttributeGroupsObjects = DA.AttributeGroups() #Filter for an array of attribute group objects called Bob Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Design Assessment NameFilterAttributeGroupsObject = DA.AttributeGroups(«Bob») #Filter for an array of attribute groups with type Sam, subtype Phil TypeFilterAttributeGroupsObject = DA.AttributeGroups(«Sam», «Phil») #Returns the total number of attribute groups print str(DA.AttributeGroupCount) #Solution Selection: #Obtain all solution selection objects AllSolutionSelections = DA.SolutionSelections() #DA Results: #Obtain an array of all DA Result objects. AllDAResultsObjects = DA.DAResults() #Filter for an array of DA Result objects called John NameFilterDAResultsObject = DA.DAResults(«John») #Filter for an array of DA Result with with type Paul, subtype Mike TypeFilterDAResultsObject = DA.DAResults(«Paul», «Mike») #Returns the total number of DA Result objects print str(DA.DAResultCount) #Access first object in NameFilterAttributeGroupsObject array if (NameFilterAttributeGroupsObject != None): AGObjectA = NameFilterAttributeGroupsObject[0] #Example Loop around Array AllAttributeGroupsObjects for AGObject in AllAttributeGroupsObjects: #Now AGObject is a representation of each Attribute Group. print AGObject.TreeName runClassDemo_DesignAssessment()

Typical Evaluate (or Solve) Script Output The output will depend upon the number of Attribute Group and DA Result objects defined and used in the model. MKS HelpFileExample—Design Assessment (B5) 1 1 Attribute Group

Helper class This class provides some general functions to assist the user writing scripts. Table 96: Members Name

Type Description

GeometryPath

string Returns the directory where the Geometry file is saved.

ResultPath

string Returns the directory where the Result files should be written. During the solving process this can be an intermediate directory, not the project system directory.

SystemDirectory

string Returns the project system directory.

UserFilesDirectory

string Returns the user_files directory for the current project.

RunMAPDL(string input, string output, string CommandLineParams)

void

1234

Runs an instance of the Mechanical APDL solver. You must provide file names which may include the full path or may be in the application or current directory for input and output. Specify any additional MAPDL command line parameters for CommandLineParams, or a blank string if none are required.

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Design Assessment API Reference Name

Type Description

SetLastError(string errorString)

void

Sets the text message to show in the output messages of the editor. This can be used to present a message to the user of the script for a reason for failure,

ReplaceSolverOutputFile(string FileLoc)

void

Specifies a text file produced during output to replace the default solve.out log file. The solve.out log file will be shown in the Solution Information Worksheet view if selected from the drop down.

SolverOutputFilePath

string Gets the file name and path of the file that is displayed when the Solution Output displays the Solver Output data.

AppendToSolverOutputFile(string AdditionalText)

void

Appends a line of text to the Solver Output display.

ClearSolverOutputFile()

void

Deletes contents of the Solver Output File.

Example Usage The following example can be used as a basis of either the solve or evaluate script. def runClassDemo_Helper(): HelperObject = DesignAssessment.Helper #Get the helper object #Obtain some Helper based properties and print them to the debug file. print «GeometryPath = » + HelperObject.GeometryPath print «ResultPath = » + HelperObject.ResultPath print «SystemDirectory = » + HelperObject.SystemDirectory print «SolverOutputFilePath = » + HelperObject.SolverOutputFilePath #Use some Helper based design assessment methods #Create a text file with write access in the result path location NewSolverFilePathAndName = HelperObject.ResultPath+»\\MySolverFile.txt» MySolverFile = open(NewSolverFilePathAndName, «w») MySolverFile.write(«This is a solver output file\n») MySolverFile.write(«The backslash n indicates the end of a line\n») MySolverFile.close() #Make the solver output file text to be that contained in the MySolverFile HelperObject.ReplaceSolverOutputFile(NewSolverFilePathAndName) #uncomment out the below line to clear the previously entered text #HelperObject.ClearSolverOutputFile() #Append some more text, note this automatically includes the new line code. HelperObject.AppendToSolverOutputFile(«My First Additional Line») HelperObject.AppendToSolverOutputFile(«My Second Additional Line») runClassDemo_Helper()

Typical Evaluate (or Solve) Script Output GeometryPath = D:\Data\Documents\HelpFileExample_files\dp0\SYS\DM\SYS.agdb ResultPath = D:\Data\Documents\HelpFileExample_files\dp0\SYS-1\MECH\ SystemDirectory = D:\Data\Documents\HelpFileExample_files\dp0\SYS-1\MECH\ SolverOutputFilePath = D:\Data\Documents\HelpFileExample_files\dp0\SYS-1\MECH\solve.out

Typical Solver Output This is a solver output file The backslash n indicates the end of a line My First Additional Line My Second Additional Line

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Using Design Assessment

MeshData class This class provides access to the mesh created for the analysis, including all elements and nodes, which can be filtered or obtained as required. Table 97: Members Name

Type

Description

NodeCount

int

Total of number of nodes in this mesh

ElementCount

int

Total of number of elements in this mesh

ElementById(int Id)

DAElement class

Obtains the DAElement class object with the given Id. Represents a single element in the Mesh.

Elements()

DAElement[] class

Array of all DAElement class objects. representing all the elements in the mesh

NodeById(int Id)

DANode class

Obtains the DANode class object with the given Id. Represents a single node in the Mesh

Nodes()

DANode[] class

Array of all DANode class objects representing all the nodes in the mesh

NodesByIds (int[] Ids)

DANode[] class

Array of DANode class objects that belong to any of the array of element Ids specified in ids.

ElementsByIds(int[] Ids)

DAElement[] class

Array of DAElement class objects that belong to any of the array of element Ids specified in Ids.

Example Usage The following example can be used as a basis of either the solve or evaluate script. #we need to use arrays for the ElementsByIds and NodesByIds methods from System import Array def runClassDemo_MeshData(): MeshDataObject = DesignAssessment.MeshData #Get the MeshData object #Output some data to the debug log file. print «Number of Nodes = » + str(MeshDataObject.NodeCount) print «Number of Elements = » + str(MeshDataObject.ElementCount) #Loop around all element objects. for ElementIterator in MeshDataObject.Elements(): print «ElementId = » + str(ElementIterator.Id) #Three ways of getting elements. #It can not be assumed that Element Ids start at 1 and are contiguous Elements = MeshDataObject.Elements() FirstElementId = Elements[0].Id ByIdMethodElement = MeshDataObject.ElementById(FirstElementId) # print true if they are the same Id. print str(FirstElementId == ByIdMethodElement.Id) # Create an Array so we can iterface with the .NET code ElementIdArray = Array[int]([FirstElementId,MeshDataObject.Elements()[1].Id]) print ElementIdArray #Pass the array into the ElementsById method. ByIdArrayMethodElement = MeshDataObject.ElementsByIds(ElementIdArray) # print true if they are the same Id. print str(FirstElementId == ByIdArrayMethodElement[0].Id) #Three ways of getting nodes. #It can not be assumed that Node Ids start at 1 and are contiguous Nodes = MeshDataObject.Nodes()

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Design Assessment API Reference FirstNodeId = Nodes[0].Id ByIdMethodNode = MeshDataObject.NodeById(FirstNodeId) # print true if they are the same Id. print str(FirstNodeId == ByIdMethodNode.Id) # Create an Array so we can iterface with the .NET code NodeIdArray = Array[int]([FirstNodeId,MeshDataObject.Nodes()[1].Id]) print NodeIdArray #Pass the array into the NodesById method. ByIdArrayMethodNode = MeshDataObject.NodesByIds(NodeIdArray) # print true if they are the same Id. print str(FirstNodeId == ByIdArrayMethodNode[0].Id) runClassDemo_MeshData()

Typical Evaluate (or Solve) Script Output The output will depend upon the mesh used in the model. Number of Nodes = 457 Number of Elements = 236 ElementId = 237 ElementId = 238 …. ElementId = 470 ElementId = 471 ElementId = 472 True Array[int]((237, 238)) True True Array[int]((1, 3)) True

DAElement class This class represents an element on the mesh for this model, providing access to the element, its connectivity and, if it is a beam or tube, the associated section data. Table 98: Members Name

Type

Description

Description

string

A description of the element: Tetrahedral Hexagonal Wedge Pyramid Triangle Triangle,Shell Quadrilateral Quadrilateral,Shell Line Point

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Using Design Assessment Name

Type

Description EMagLine EMagArc EMagCircle Surface Edge Beam Special

CrossSectionData

SectionData class

Section data for this element, describes beam cross sections for beam types; Only elements that have a Circular Hollow Section, Rectangular Hollow Section or I Section are supported, all other elements will return NULL

NodeIds()

int[]

Array of integer values representing Ids of the Element’s Nodes

Nodes()

DANode[] class

Array of DANode class objects for each node of this Element

Id

int

Returns the unique Id number of this Element

NodeCount

int

Returns the number of Nodes for this Element

ElementThickness

double

The shell thickness of the element. If the element is not a shell, the value returned will be zero. Where shell thickness can be applied via geometry or by a Shell Thickness object, that defined by the Shell Thickness will take precedence.

ElementThicknessAtNode(NodeId) double

The shell thickness of the element at position of Node with NodeId. If the element is not a shell, the value returned will be zero. Where shell thickness can be applied via geometry or by a Shell Thickness object, that defined by the Shell Thickness will take precedence. If shell thickness varies across the element then it is determined by the average thickness of the element nodes.

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Design Assessment API Reference

Example Usage The following example can be used as a basis of either the solve or evaluate script. def runClassDemo_DAElement(): #Loop around all element objects. for ElementIterator in DesignAssessment.MeshData.Elements(): #General info: print «Element Description = » + ElementIterator.Description print «Element Id = » + str(ElementIterator.Id) # Information about the nodes of the element print «Number of connected Nodes = » + str(ElementIterator.NodeCount) NodeIdArray = ElementIterator.NodeIds() print NodeIdArray ConnectedNodeObjects = ElementIterator.Nodes() #Cross Section Data is only available for beams. #First test to see if it’s a beam as they support it. if ‘Beam’ in ElementIterator.Description: XSectionDataObj = ElementIterator.CrossSectionData #Element Thickness only applies to some elements, returns 0.0 if not supported. print «Element Thickness = » + str(ElementIterator.ElementThickness) ThicknessAtNode = ElementIterator.ElementThicknessAtNode(NodeIdArray[0]) print «Thickness at Node Id » + str(NodeIdArray[0]) + » = » + str(ThicknessAtNode) runClassDemo_DAElement()

Typical Evaluate (or Solve) Script Output The output will depend upon the elements used in the model; this output is for beams. Element Description = Beam Element Id = 237 Number of connected Nodes = 3 Array[int]((1, 3, 222)) Element Thickness = 0.0 Thickness at Node Id 1 = 0.0

DANode class This class represents a node on the mesh for this analysis. It can be used to find the coordinates of the node and the elements that it is connected to. Table 99: Members Name

Type

Description

Id

int

Returns the unique Id number of this Node

X

double

Returns the x coordinate of this Node in solver units as set in Analysis settings

Y

double

Returns the y coordinate of this Node in solver units as set in Analysis settings

Z

double

Returns the z coordinate of this Node in solver units as set in Analysis settings

ConnectedElementIds()

int[]

Array of integer values representing Ids of the connected Elements

ConnectedElements()

DAElement[] class

Array of DAElement class objects that represent the elements that this Node is connected to

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Using Design Assessment Name

Type

Description

ConnectedElementCount

int

Returns the number of Elements this node is connected to

IsOrientationNode

bool

Some beam nodes are created to orient the local axis system for the section; if this node is used for orientation this function will return true Note: results cannot be displayed on orientation nodes

Example Usage The following example can be used as a basis of either the solve or evaluate script. def runClassDemo_DANode(): #Loop around all nodes. for NodeIterator in DesignAssessment.MeshData.Nodes(): #General info: print «Node Id = » + str(NodeIterator.Id) print «Node X = » + str(NodeIterator.X) print «Node Y = » + str(NodeIterator.Y) print «Node Z = » + str(NodeIterator.Z) print «Node only used for beam orientation? » + str(NodeIterator.IsOrientationNode) # Information about the elements that connect to this node print «Number of connected Elements = » + str(NodeIterator.ConnectedElementCount) ElementIdArray = NodeIterator.ConnectedElementIds() print «Connected Element Ids = » + str(ElementIdArray) ConnectedElementObjects = NodeIterator.ConnectedElements() runClassDemo_DANode()

Typical Evaluate (or Solve) Script Output The output will depend upon the nodes used in the model. Node Id = 1 Node X = -2.0 Node Y = 4.4408920985e-16 Node Z = 5.0 Is the node only used for beam orientation? False Number of connected Elements = 4 Connected Element Ids = Array[int]((408, 400, 245, 237))

SectionData class This class provides Section Data properties for a beam based element in solver units as set in Analysis settings. It can be accessed via DAElement. Table 100: Members Name

Type

Description

Description

string

Returns a description of the type of cross section: CHS,Tube I,Beam RHS,Beam

TubeDiameter

double Returns the Diameter as double, only applicable to sections that are tubular

TubeThickness

double Returns the Thickness as double, only applicable to sections that are tubular

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Design Assessment API Reference Name

Type

Description

BeamWebThickness

double Returns the WebThickness as double, only applicable to sections that are beam based

BeamFlangeThickness

double Returns the FlangeThickness as double, only applicable to sections that are beam based

BeamFilletRadii

double Returns the FilletRadii as double, only applicable to sections that are beam based

BeamHeight

double Returns the Height as double, only applicable to sections that are beam based

BeamWidth

double Returns the Width as double, only applicable to sections that are beam based

Example Usage The following example can be used as a basis of either the solve or evaluate script. def runClassDemo_SectionData(): #Loop around all element data objects. for ElementIterator in DesignAssessment.MeshData.Elements(): #Cross Section Data is only available for beams. #First test to see if it’s a beam as they support it. if ‘Beam’ in ElementIterator.Description: XSectionData = ElementIterator.CrossSectionData print XSectionData.Description if ‘Tube’ in XSectionData.Description: print «Diameter = » + str(XSectionData.TubeDiameter) print «Thickness = » + str(XSectionData.TubeThickness) if ‘Beam’ in XSectionData.Description: print «Web Thickness = » + str(XSectionData.BeamWebThickness) print «Flange Thickness = » + str(XSectionData.BeamFlangeThickness) print «Fillet Radii = » + str(XSectionData.BeamFilletRadii) print «Height = » + str(XSectionData.BeamHeight) print «Width = » + str(XSectionData.BeamWidth) runClassDemo_SectionData()

Typical Evaluate (or Solve) Script Output The output will depend upon the elements used in the model; this output is for a tube and a beam. CHS,Tube Diameter = 0.5 Thickness = 0.01 I,Beam Web Thickness = 0.01 Flange Thickness = 0.01 Fillet Radii = 0.03 Height = 0.65 Width = 0.5

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Using Design Assessment

AttributeGroup class This class represents the Attribute Group entries in the tree view and provides access to the data entered. This tree object is defined in the AttributeGroups section of the XML definition file. Table 101: Members Name

Type

Description

Attributes()

Attribute[] class

Array of all the Attribute class objects held under this AttributeGroup

Attribute(int index)

Attribute class

An Attribute class object at the index as defined in the AttributeIDs field in the XML definition file. Index is zero based.

Attribute(string XMLName)

Attribute class

An Attribute class object of the name defined in the XML definition file, from the Attribute array

AttributeCount

int

The number of Attribute class objects in the Attribute array

TreeName

string

The name of this AttributeGroup as defined by the user in the user interface

XmlType

string

The Type of this AttributeGroup as defined in the XML definition file

XmlSubType

string

The Sub Type of this AttributeGroup as defined in the XML definition file

Example Usage The following example can be used as a basis of either the solve or evaluate script. def runClassDemo_AttributeGroups(): #Loop around all attribute group objects. for AGIterator in DesignAssessment.AttributeGroups(): #Attribute Group info print «Name = » + AGIterator.TreeName print «Type = » + AGIterator.XmlType print «Subtype = » + AGIterator.XmlSubType #Obtaining contained attributes print «No of Attributes = » + str(AGIterator.AttributeCount) Index = 0 for AttributeIterator in AGIterator.Attributes(): #Get the name of this attribute AName = AttributeIterator.AttributeName #Get the attribute, based on the index AttributeMethod1 = AGIterator.Attribute(Index) #Get the attribute, based on the Name, it’s easier to look up by name. AttributeMethod2 = AGIterator.Attribute(AName) print «Attribute Name: » + AName print «Check names are the same: » + str(AName == AttributeMethod1.AttributeName) print «Are attrib. objects the same: » + str(AttributeMethod1 == AttributeMethod2) #Add to the index (there are more concise ways of doing this in a loop) Index = Index + 1 runClassDemo_AttributeGroups()

Typical Evaluate (or Solve) Script Output The output will depend upon the XML definition file used in the model and the attribute groups used. Name = Attribute Group Type = Geometry Factor Subtype = My Factors No of Attributes = 1

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Design Assessment API Reference Attribute Name: Factor Check names are the same: True Are attrib. objects the same: True

Attribute class This class provides access to the input provided for each attribute in the attribute group. The attributes are defined in the Attributes section of the XML definition file. Table 102: Members Name

Type

Description

AttributeName

int

The name of this Attribute

ValueAsInt

int

Returns the value entered as an integer; double values will be truncated. Accepted input is determined by the XML definition file.

ValueAsDouble

double

Returns the value entered as a double. Accepted input is determined by the XML definition file.

ValueAsString

string

Returns the value entered as text; if the value is numerical, it will automatically be converted to text. Accepted input is determined by the XML definition file.

SelectedElementCount

int

Returns the number of elements included in the selected geometry

SelectedElements()

DAElement[] class

Returns an array of DAElements included in the selected geometry

SelectedNodeCount

int

Returns the number of nodes included in the selected geometry

SelectedNodes()

DANode[] class

Returns an array of DANodes included in the selected geometry

Note The functions SelectedNodes and SelectedElements will return None if no geometry is specified. These functions, plus the SelectedNodeCount and SelectedElementCount are only valid if the <Application> field in the attributes section of the XML definition file is used to enable geometry selection.

Example Usage The following example can be used as a basis of either the solve or evaluate script. def runClassDemo_Attributes(): #Loop around all attribute group objects for AGIterator in DesignAssessment.AttributeGroups(): for AttributeIterator in AGIterator.Attributes(): #Get info about the attribute print «Attribute Name = » + AttributeIterator.AttributeName print «Value via ValueAsInt = » + str(AttributeIterator.ValueAsInt) print «Value via ValueAsDouble = » + str(AttributeIterator.ValueAsDouble) print «Value via ValueAsString = » + AttributeIterator.ValueAsString print «No Elements in Selection = » + str(AttributeIterator.SelectedElementCount) print «1st Element in Selection = » + str(AttributeIterator.SelectedElements()[0]) print «No of Nodes in Selection = » + str(AttributeIterator.SelectedNodeCount) print «First Node in Selection = » + str(AttributeIterator.SelectedNodes()[0]) runClassDemo_Attributes()

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Using Design Assessment

Typical Evaluate (or Solve) Script Output The output will depend upon the XML definition file used in the model and the attributes and attribute groups used. Attribute Name = Factor Value via ValueAsInt = 1 Value via ValueAsDouble = 1.0 Value via ValueAsString = 1 No Elements in Selection = 236 1st Element in Selection =

No of Nodes in Selection = 221 First Node in Selection =

SolutionSelection class This class represents the Solution Selection object in the tree view and provides access to the Solutions entered in the Worksheet view. Each solution represents an upstream analysis. Table 103: Members Name

Type

Description

Solutions()

Solution[] class

Array of all the Solution class objects held under this Solution Selection, each being a row of the table.

SolutionByRow(int row)

Solution class

A Solution class object at the given row in the SolutionSelections worksheet, a one based value, so to obtain the Solution class object for the first row, enter 1

SolutionCount

int

The number of Solution class objects in the Solutions array

Example Usage The following example can be used as a basis of either the solve or evaluate script. def runClassDemo_SolutionSelection(): #Loop around all solution selection objects (NB only 1 currently supported) for SolutionSelectionIterator in DesignAssessment.SolutionSelections(): print «No of Solutions in selection = » + str(SolutionSelectionIterator.SolutionCount) print «1st row in Solseln = » + str(SolutionSelectionIterator.SolutionByRow(1).Id) for SolutionIterator in SolutionSelectionIterator.Solutions(): print «Id for solution = » + str(SolutionIterator.Id) runClassDemo_SolutionSelection()

Typical Evaluate (or Solve) Script Output The output will depend upon the XML definition file used in the model and the attributes and attribute groups used. No of Solutions in selection = 1 1st row in Solseln = 23 Id for solution = 23

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Design Assessment API Reference

Solution class This class represents a row in the Worksheet of the Solution Selection tree object. Table 104: Members Name

Type

Description

AdditionalSolutionData()

string[]

Array of strings representing all the additional data entered in to the Solution Selection table additional data columns

AdditionalSolutionDataByColumn(int Column)

string

The string object at the Column of the AdditionalSolutionData

AdditionalSolutionDataCount

int

The number of AdditionalSolutionData text files in the AdditionalSolutionData array

Id

int

The unique Id number for the solution. Solution Id’s do not change once the solution is created.

Type

string

The type of solution as defined by the description: Static Structural Transient Structural Explicit Dynamics Modal Harmonic Response Random Vibration Response Spectrum

CreateSolutionResult()

SolutionResult class

Create a new result based on this analysis system. Returns the created object.

CreateSolutionResult(string Name)

SolutionResult class

Create a new result of the given Name based on this analysis system. Returns the created object.

CreateSolutionResult(string Name, string Expression, string ResultType)

SolutionResult class

Create a new result of the given Name, Expression and ResultType based on this analysis system. Returns the created object. ResultType string should be set to one of the values listed for DisplayUnits keyword in the

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Using Design Assessment Name

Type

Description DAResult section of the XML definition file.

CreateSolutionResultSets(int NumSets)

SolutionResult[] class

Creates a number of new Solution Result objects determined by the given NumSets, based on this Solution. These Solution Results are substeps spread evenly across the result step provided by the definition in the Solution Selection table. The created Solution Result objects are then returned in the form of an array.

CreateSolutionResultSets(int NumSets, string Name)

SolutionResult[] class

Creates a number of new Solution Result objects determined by the given NumSets and Name, based on this Solution. These Solution Results are substeps spread evenly across the result step provided by the definition in the Solution Selection table. The created Solution Result objects are then returned in the form of an array.

CreateSolutionResultSets(int NumSets, string Name, string Expression, string ResultType)

SolutionResult[] class

Creates a number of new Solution Result objects determined by the given NumSets, Name, Expression and ResultType, based on this Solution. These Solution Results are substeps spread evenly across the result step provided by the definition in the Solution Selection table. The created Solution Result objects are then returned in the form of an array. ResultType string should be set to one of the values listed for DisplayUnits keyword in the DAResult section of the XML definition file.

ClearSolutionResultSets()

void

Clears all SolutionResult objects created for this Solution class.

SolutionResults()

SolutionResult[] class

Array of results containing all the result objects.

SolutionResults(string Name)

SolutionResult[] class

Array of results containing specific results filtered on the given Name.

Units

string

Returns the Units used in this solution, represented as a string: CGS

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Design Assessment API Reference Name

Type

Description NMM LBFT LBIN UMKS MKS No Units System

ResultFilePath

string

String representing the solution combination result file path (rst file) for the loadcase.

Time

double

Gets the value of time that has been entered by the user in the Solution Selection table, if applicable.

Freq

double

Gets the value of frequency that has been entered by the user in the Solution Selection table, if applicable.

Coefficient

double

Gets the Coefficient entered by the user.

Phase

double

Gets the value of Phase Angle that has been entered by the user in the Solution Selection table, if applicable.

Mode

int

Gets the value of Mode that has been entered by the user in the Solution Selection table, if applicable.

StepStartTime

double

Gets the value of the start time that has been entered by the user in the Solution Selection table, if applicable.

StepEndTime

double

Gets the value of the end time that has been entered by the user in the Solution Selection table, if applicable.

StepMinFrequency

double

Gets the value of the minimum frequency that has been entered by the user in the Solution Selection table, if applicable.

StepMaxFrequency

double

Gets the value of the maximum frequency that has been entered by the user in the Solution Selection table, if applicable.

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Using Design Assessment Name

Type

Description

StepCount

int

Returns the number of inclusive steps used in this Upstream Solution. This is only applicable when the Solution is based on a Static or Transient analysis type.

SubstepCount

int

Returns the number of inclusive substeps used in this Upstream Solution. This is only applicable when the Solution is based on a Static, Transient or Explicit analysis type.

Steps()

Int[]

Gets an array of inclusive step numbers used in this Upstream Solution. This is only applicable when the Solution is based on a Static or Transient analysis type.

Substeps()

Int[]

Gets an array of inclusive Substep numbers used in this Upstream Solution. This is only applicable when the Solution is based on a Static, Transient, or Explicit analysis type.

TimePoints()

Double[]

Gets an array of result time points for all inclusive Substeps used in this Upstream Solution. This is only applicable when the Solution is based on a Static, Transient, or Explicit analysis type.

MultipleSets

bool

Returns True if the Solution has Multiple Sets set to ‘Enabled’ in the Solution Selection table.

Example Usage The following example can be used as a basis of either the solve or evaluate script. def runClassDemo_Solution2(): #Get all results called bob and set the expression to SX. AllBobs = DesignAssessment.SolutionSelections()[0].SolutionByRow(1).SolutionResults(«Bob») for BobResultIter in AllBobs: print «Bob found at » + str(BobResultIter) BobResultIter.Expression = «SX» def runClassDemo_Solution(): #Get the first entered upstream solution. UpstreamSoln = DesignAssessment.SolutionSelections()[0].SolutionByRow(1) #Get properties that identify this solution. print «Id = » + str(UpstreamSoln.Id) print «Type = » + str(UpstreamSoln.Type) #Get properties defined for this entry in the solution selection worksheet print «Time = » + str(UpstreamSoln.Time) print «Frequency = » + str(UpstreamSoln.Frequency) print «Phase = » + str(UpstreamSoln.Phase)

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Design Assessment API Reference print print print print

«Mode = » + str(UpstreamSoln.Mode) «Coefficient = » + str(UpstreamSoln.Coefficient) «Result File Path = » + str(UpstreamSoln.ResultFilePath) «Units system used = » + str(UpstreamSoln.Units)

#XML defined properties in the solution selection worksheet print «Number of Additional strings = » + str(UpstreamSoln.AdditionalSolutionDataCount) print «Additional strings = » + str(UpstreamSoln.AdditionalSolutionData()) print «Additional string, col 1 = » + str(UpstreamSoln. AdditionalSolutionDataByColumn(1)) #Create a new result object for this solution #this object can then be used directly to set expressions, etc. MyResult = UpstreamSoln.CreateSolutionResult() #Use the Name for identification, #useful to obtain the results in another subroutine in python. MyBobResult = UpstreamSoln.CreateSolutionResult(«Bob») MyFredResult = UpstreamSoln.CreateSolutionResult(«Fred») My2ndBobResult = UpstreamSoln.CreateSolutionResult(«Bob») #Define expression at same time as creating the result. MySXDefinedResult = UpstreamSoln.CreateSolutionResult(«FredSX»,»sx») runClassDemo_Solution()

Typical Evaluate (or Solve) Script Output The output will depend upon the XML definition file used in the model and the attributes and attribute groups used. Id = 23 Type = Static Structural Time = 1.0 Frequency = 0.0 Phase = 0.0 Mode = 0 Coefficient = 1.0 Result File Path = D:\Data\Documents\HelpFileExample_files\dp0\SYS\MECH\file.rst Units system used = MKS Number of Additional strings = 1 Additional strings = Array[str]((»)) Additional string, col 1 = Bob found at

Bob found at

SolutionResult class This class holds the solution result data that can be accessed, directly related to the solution. The solution result class will be initialized with the unit system specified for the Design Assessment analysis. Only when a valid unit system and type are set will results obtained be converted correctly to the expected result units. Results are organized in sets; each set contains the results at a given time, frequency, etc. depending upon the analysis type. It is more efficient to get all the required results at a given set, before changing sets. For convenience the set can be identified automatically by defining a time or frequency. If the value is not exact then the results will be interpolated from the adjacent values.

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Using Design Assessment If the value cannot be obtained (for example, requesting elemental values for a nodal result), the maximum value for a double type is returned (1.79769e+308).

Note DefineCoordinateSystem and CoordinateSystem are mutually exclusive; if both are used, the last one defined takes precedence. Table 105: Members Name

Type

Description

Name

string

Gets or sets the name of the result, so that it can be found from the solution class.

ElementNodalValues(int ElementId, int NodeId)

double[]

Array of values of an element nodal result at the given ElementId and NodeId. The size of the returned array will depend upon the number of result components. If required, this can be determined using ComponentCount or the python len() function.

ElementalValues(int ElementId)

double[]

Array of values of an element result at the given ElementId. The size of the returned array will depend upon the number of result components. If required, this can be determined using ComponentCount or the python len() function.

NodalValues(int NodeId)

double[]

Array of values of a nodal result at the given NodeId. The size of the returned array will depend upon the number of result components. If required, this can be determined using ComponentCount or the python len() function.

DisplayStyle

string

Returns the DisplayStyle: i.e. if it’s a Vector, Tensor, Scalar, etc. The returned string can be used to programmatically set the ResultGroup’s DisplayStyle. Note: the returned value is dependent on provided Expression and IntegrationMethod, so these should be called beforehand.

DisplayType

string

Returns the DisplayType: i.e. if it’s a Nodal, Elemental or ElementNodal result. The returned string can be used to programmatically set the ResultGroup’s DisplayType. Note: the returned value is dependent on provided Expression and IntegrationMethod, so these should be called beforehand.

ComponentCount

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int

Returns the number of components for this result, typically 1, 3, or 6.

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Design Assessment API Reference Name

Type

Description Note: the returned value is dependent on provided Expression and IntegrationMethod, so these should be called beforehand.

ResultSetCount

int

Returns the total number of results sets for this system. The Result Set count is read directly from the underlying file containing the results..

Expression

string

Set the expression by assigning a string. Valid expressions are the same as those used for user defined results and can include mathematical modifiers.

CoordinateSystem

string

Sets the coordinate system type by assigning a string. Valid inputs are either the name of a user coordinate system in the Mechanical application or one of the following: Global (default) Solution The solution coordinate system is generally associated with beam based results.

DefineCoordinateSystem(string Axes, double Axis1X, double Axis1Y, double Axis1Z, double Axis2X, double Axis2Y, double Axis2Z, double OriginX, double OriginY, double OriginZ)

void

Defines a custom coordinate system orientation matrix to obtain results in. Use as an alternative to CoordinateSystem to enable an axis to be defined directly in the python code. Axes is one of the following strings used to define what two axes of the orientation matrix are being entered, the third axis is calculated automatically. XY YZ ZX

SetUnitsSystem(string UnitsSystem, string RotationUnit, string TemperatureUnit)

void

Defines the units system that the results are to be obtained in. If a string is blank, then the default is assumed. Options for UnitsSystem are: MKS: i.e. Metric (m, Kg, N, s, V, A), (Default) UMKS: i.e. Metric (µm, Kg, µN, s, mV, mA) CGS: i.e. Metric (cm, g, dyne, s, V, A) NMM: i.e. Metric (mm, Kg, N, s, mV, mA) LBFT: i.e. US Customary (ft, lbm, lbf, s, V, A)

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Type

Description LBIN: i.e. US Customary (in, lbm, lbf, s, V, A) Options for RotationUnit are: Degrees Radians (Default) Options for TemperatureUnit are: Kelvin Celsius (Default for metric systems) For US Customary, Fahrenheit is always used and the entered value is ignored.

ResultType

string

Gets or Sets the ResultType. ResultType string should be set to one of the values listed for DisplayUnits keyword in the DAResult section of the XML definition file. No Units is the default value. If not set or left as default No Units, any results obtained will not be unit converted to the appropriate units for the Design Assessment system.

IntegrationMethod

string

Defines the integration method used when obtaining results by assigning a string. Valid options are: UnAveraged Averaged (default) Nodal Difference Nodal Fraction Elemental Mean Elemental Difference Elemental Fraction Different Integration options can affect the DisplayType.

ResultSet

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int

Defines the set that data is obtained from by assigning an integer value. It is recommended that this method is used to specify which results are to be obtained for Modal,

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Type

Description Spectrum, and Response Spectrum analyses. Assigning 0 will obtain data from the last result set in the analysis. Default is based on the entry in the Solution Selection table.

ResultTimeFrequency

double

Defines the time or frequency that data is obtained from by assigning a real number to indicate the time or frequency. Whether it is defining Time or Frequency1 (p. 1253) is determined automatically from the analysis type. Assigning 0.0 will obtain data from the last time or frequency in the analysis. If the analysis is time or frequency independent then the ResultSet property can be used instead. Default is based on the entry in the Solution Selection table.

ShellLayer

int

Define the layer for which to obtain results. In the case of composite sections, assigning ShellLayer to a positive integer can be used to define the layer number. Alternatively, assign 0 for the whole section; this is default behavior. See also ShellFaceResultDisplay. Only applicable to shell elements.

ShellFaceResultDisplay

string

Define what results are displayed on the faces of shell elements by assigning a string. Valid entries are: Top (i.e. results calculated for the top face on both faces) Bottom (i.e. results calculated for the bottom face on both faces) Middle (i.e. calculated middle values on both faces — see Layered and Surface Body Results (p. 875) for details) Only applicable to shell elements.

1 — Obtaining frequency based results is not presently supported.

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Example Usage The following example can be used as a basis of either the solve or evaluate script. def runClassDemo_SolutionResult(): #Create a scripted, user defined, result MyRes = DesignAssessment.SolutionSelections()[0].SolutionByRow(1).CreateSolutionResult() #Define what result we’re obtaining. MyRes.Expression = «UX» #You can specify the solution or Global system.. MyRes.CoordinateSystem = «Solution» #Alternatively, define a coordinate system directly. #The last CS defined takes precidence. #MyRes.DefineCoordinateSystem(«ZX»,1,0,0,0,1,0,0,0,0) #Define the units sytem and the units type to convert the results. #MyRes.SetUnitsSystem(«UMKS»,»Radians»,»Celsius»,»Distance») #Define the method of integrating the results, this can affect the result type. #MyRes.IntegrationMethod = «UnAveraged» #Set the time or set for the results that we want to obtain, #last one defined takes precidence. MyRes.ResultSet = 0 MyRes.ResultTimeFrequency = 0 #Get some info about this result DS = MyRes.DisplayStyle print DS DT = MyRes.DisplayType print DT NC = MyRes.ComponentCount print NC NRS = MyRes.ResultSetCount print NRS #Loop around all elements objects. for ElementIter in DesignAssessment.MeshData.Elements(): print «Element Values = » + str(MyRes.ElementalValues(ElementIter.Id)) for NodeIter in ElementIter.Nodes(): Values = str(MyRes.ElementNodalValues(ElementIter.Id,NodeIter.Id)) print «Element Nodal Result Values = » + Values #Loop around all node objects. for NodeIterator in DesignAssessment.MeshData.Nodes(): print «Node Result Values = » + str(MyRes.NodalValues(NodeIterator.Id)) runClassDemo_Solution()

Typical Evaluate (or Solve) Script Output The output will depend upon the model. Scalar Nodal 1 1 Element Value = Array[float](( 1.7976931348623157e+308)) Element Nodal Result Values = Array[float]((-2.5374282230927747e-08)) Element Nodal Result Values = Array[float]((-1.6870160379767185e-08)) Element Nodal Result Values = Array[float]((-9.8640562384844088e-09)) …. Node Result Values = Array[float]((-4.6618247040441929e-08)) Node Result Values = Array[float]((-3.7071398395482902e-08)) Node Result Values = Array[float]((-2.8261506912485856e-08)) ….

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Design Assessment API Reference

DAResult class This class provides access to the results objects, and enables the user to set the results that are to be displayed when the result object is selected. The DAResult is defined in the DAResults section of the XML definition file. Table 106: Members Name

Type

Description

TreeName

string

Returns the user defined name of this result instance

XmlType

string

Returns the text string of the Type of this result instance; the Type is set in the user interface by a drop down list (as defined in the XML definition file)

XmlSubType

string

Returns the text string of the Sub Type of this result instance; the Sub Type is set in the user interface by a drop down list (as defined in the XML definition file)

DAResultSetCount

int

Total number of sets that are available for this result

CreateDAResultSet()

DAResultSet class

Creates a new result set and returns it so that values can be defined within it DisplayStyle and DisplayType will be read from values in the XML definition file, or if multiple DAResultSets are created, they’ll be read from the first set.

CreateDAResultSet(string DisplayStyle, string DisplayType)

DAResultSet class

Creates a new result set and returns it so that values can be defined within it overrides the DisplayStyle entered in the XML definition file for this result group. However, unlike the XML definition file setting, defining it here does not enable the option to choose the component in the user interface of the DA Result object. However, this option can be used to force the display to show either a Vector or Tensor result; 3 or 6 component values should be defined accordingly. DisplayStyle strings should be set to one of the values listed for the DisplayStyle keyword in the DAResult section of the XML definition file. DisplayType overrides the DisplayType entered in the XML definition file, and should be a valid DisplayType keyword in the DAResult section of the XML definition file.

DAResultSets()

DAResultSet[] class

DAResultSet(int SetNumber) DAResultSet class

Returns an array of DAResultSets classes from the DAResultSet collection for this DAResult Returns a single DAResultSet object for the given SetNumber. SetNumber is 1 based and incremented automatically with each set that is added.

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Type

Description

AttributeCount()

int

Total number of Attributes objects defined

Attributes()

Attribute[] class

Array of Attribute class objects; the Attribute collection for this DAResult as Attribute class type

Attribute(string XMLName)

Attribute class

An Attribute class object of the name defined in the XML definition file, from the Attribute array

Attribute(int index)

Attribute class

An Attribute class object at the index as defined in the AttributeIDs field in the XML definition file. Index is zero based.

DisplayStyle

string

Gets the type of display, as defined in the XML definition file, or as defined when creating a result set; Scalar, Vector, Tensor, or StrainTensor.

DisplayType

string

Gets the type of display, as defined in the XML definition file or as defined when creating a result set; Elemental, Nodal, or ElementNodal.

DisplayUnits

string

Gets or sets the DisplayUnits set programmatically. By default it’s obtained from the display units set via the XML definition file for this DAResult. If setting it, the string should be set to one of the values listed for DisplayUnits keyword in the DAResult section of the XML definition file.

IsUpToDate

bool

This will return true if the DAResult is currently Up To Date, otherwise it will return false.

Note A DAResult that is currently Up To Date is in a read-only state, and therefore its properties and results can not be modified. In order to modify the DAResult, you will need to clear it via the User Interface before solving or evaluating.

Example Usage The following example can be used as a basis of either the solve or evaluate script. def runClassDemo_DAResult(): for DAResultIter in DesignAssessment.DAResults(): #General info: print «Name = » + DAResultIter.TreeName print «XmlType = » + DAResultIter.XmlType print «XmlSubType = » + DAResultIter.XmlSubType #Show and modify display options. print «Initial DisplayType = » + DAResultIter.DisplayType print «Initial DisplayStyle = » + DAResultIter.DisplayStyle print «Initial DisplayUnits = » + DAResultIter.DisplayUnits DAResultIter.DisplayUnits = «Stress» print «New DisplayUnits = » + DAResultIter.DisplayUnits #Attribute access: print «Number of Attributes = » + str(DAResultIter.AttributeCount) myAttribute = DAResultIter.Attribute(0) myAttributeByName = DAResultIter.Attribute(«Mathematical Operator») print «Are they the same? = » + str(myAttribute == myAttributeByName) print «All attributes = » + str(DAResultIter.Attributes())

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Design Assessment API Reference

NewSet = DAResultIter.CreateDAResultSet() GetSet = DAResultIter.DAResultSet(1) print «Are they the same object? = » + str(NewSet == GetSet) print «Number of Result Sets = » + str(DAResultIter.DAResultSetCount) print «Result Sets = » + str(DAResultIter.DAResultSets()) runClassDemo_DAResult()

Typical Evaluate (or Solve) Script Output The output will depend upon the XML definition file used in the model and the attributes and attribute groups used. Name = DA Result XmlType = My Custom Result XmlSubType = Element Initial DisplayType = Elemental Initial DisplayStyle = Scalar Initial DisplayUnits = No Units New DisplayUnits = Stress Number of Attributes = 1 Are they the same? = True All attributes = Array[AttributeClass]((

)) Are they the same object? = True Number of Result Sets = 1 Result Sets = Array[DAResultSetClass](())

DAResultSet class This class provides the ability to set result values ready for displaying at the appropriate solution step. The object stores 3 types of result values: • Elemental results are for when only a single value is to be displayed for each element. • ElementNodal results are for when an element has different results at each node, but the result belongs to the element, hence there can be multiple results at a given node. • Nodal results have a value at each node. A DAResultSet is equivalent to a DAResult substep. The SubstepValue parameter enables multiple results to be calculated and displayed for a DAResult. Only results that are appropriate for the display type set in the XML definition file should be added to the object; otherwise an exception will be generated. Depending upon the display style set in the XML definition file the result can have a 1, 3 or 6 components, i.e. scalar, vector or tensor. The component input required is 1 based, i.e. use 1 in the case of scalar. Setting any value to the capacity of a double (1.79769e+308) will result in the element being displayed in a translucent manner. This is the default if a value is not defined for a particular element. Table 107: Members Name

Type

Description

SetElementalValue(int ElementId, int Component, double Value)

void

Sets an element result for a given component to the specified Value

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Type

Description

GetElementalValue(int ElementID, int Compon- double ent)

Returns the result value

SetElementalValues(int ElementId, double[] Values)

void

Sets an element result for all components to the specified Value array

GetElementalValues(int ElementId)

double []

Returns the result values for all components as an array

SetElementNodalValue(int ElementId, int NodeId, int Component, double Value)

void

Sets a node result at the NodeId of an element defined by the provided ElementId, for the specified Component. If the NodeId doesn’t exist on the given ElementId an exception will be generated.

GetElementNodalValue(int ElementId, int NodeId, int Component)

double

Returns the result for a given NodeId, ElementId, and Component. If the NodeId doesn’t exist on the given ElementId an exception will be generated.

SetElementNodalValues(int ElementId, int NodeId, double[] Values)

void

Sets a node result at the NodeId of an element defined by the provided ElementId for all components. If the NodeId doesn’t exist on the given ElementId an exception will be generated.

GetElementNodalValues(int ElementId, int NodeId)

double[] Returns the result for a given NodeId and ElementId for all components as an array. If the NodeId doesn’t exist on the given ElementId an exception will be generated.

SetNodalValue(int NodeId, int Component, double Value)

void

Sets a node result value for the given NodeId and Component

GetNodalValue(int NodeId, int Component)

double

Returns the value for the given NodeId and Component

SetNodalValues(int NodeId, double[] Values)

void

Sets a node result values for the given NodeId for all Components

GetNodalValues(int NodeId)

double[] Returns the value for the given NodeId as an array for all Components

SubstepValue

double

Sets the Substep value of this DAResultSet (i.e. Time, Frequency, Substep Number)

Example Usage The following example can be used as a basis of either the solve or evaluate script. def runClassDemo_DAResultSet(): for DAResultIter in DesignAssessment.DAResults(): #Create Result Set: Res = DesignAssessment.SolutionSelections()[0].SolutionByRow(1).CreateSolutionResult() #Set the expression and integration method, result info is dependant on these

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Examples of Design Assessment Usage Res.Expression = «UX» Res.IntegrationMethod = «Unaveraged» #Create a result based on the upstream results type and style. DT = Res.DisplayType DS = Res.DisplayStyle NewDAResultSet = DAResultIter.CreateDAResultSet(DS, DT) print DT print DS if (DT == «Elemental»): #Loop around all elements objects. for ElementIter in DesignAssessment.MeshData.Elements(): ElemId = ElementIter.Id NewDAResultSet.SetElementalValues(Id, Res.ElementalValues(Id)) elif (DT == «ElementNodal»): #Loop around all elements objects. for ElementIter in DesignAssessment.MeshData.Elements(): ElemId = ElementIter.Id #Loop around all node objects attached to the element. for NodeIter in ElementIter.Nodes(): NodeId = NodeIter.Id ResultValues = Res.ElementNodalValues(ElemId, NodeId) NewDAResultSet.SetElementNodalValues(ElemId, NodeId, ResultValues) elif (DT == «Nodal»): #Loop around all node objects. for NodeIterator in DesignAssessment.MeshData.Nodes(): NodeId = NodeIterator.Id ResultValues = Res.NodalValues(NodeId) print NodeId + » : » + str(ResultValues) NewDAResultSet.SetNodalValues(NodeId, ResultValues) runClassDemo_DAResultSet()

Typical Evaluate (or Solve) Script Output The output will depend upon the XML definition file used in the model and the attributes and attribute groups used. Nodal Scalar 1 : 9.5726960580577725e-08 2 : -8.2783643051698164e-08 3 : -7.0038652211223962e-08 4 : -1.0865198873943882e-07

Examples of Design Assessment Usage The following examples show how the Design Assessment system can be used to provide external processing during an analysis. Using Design Assessment to Obtain Results from Mechanical APDL Using Design Assessment to Calculate Complex Results, such as Those Required by ASME Using Design Assessment to Perform Further Results Analysis for an Explicit Dynamics Analysis Using Design Assessment to Obtain Composite Results Using Mechanical APDL Using Design Assessment to Access and Present Multiple Step Results Using Design Assessment to Perform an Explicit-to-Implicit Sequential Analysis The Python script and XML files described in the Design Assessment examples are available from the ANSYS Customer Portal. Go to http://support.ansys.com/docinfo and locate the Design Assessment examples zip file. Download the file and unzip it to your local disk. There is a subfolder for each Design Assessment example.

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Using Design Assessment to Obtain Results from Mechanical APDL The purpose of this example is to illustrate how to run Mechanical APDL in batch mode using Design Assessment, and how to display the results within the Workbench environment; see the Mechanical APDL Command Reference for further information. An example Mechanical APDL data file is shown below. This surf154.dat file is written to obtain surface 154 results that are not supported natively in the Mechanical application and to output them to a CSV file called data.csv. In this scenario, results are element based. Two arguments are to be passed in: • ARG1 = Result file path (without file extension) • ARG2 = Time point to obtain results

The surf154.dat file /batch /post1 FILE,ARG1 set,NEAR,,1.0,,ARG2 esel,s,ename,,154 ETABLE,my_press,smisc,13 *get,ecount,elem,0,count *dim,output,arra,ecount,10 curre = 0 *do,i,1,ecount curre = ELNEXT(curre) output(i,1) = curre *get,output(i,2),etab,1,elem,curre *enddo *cfopen,data,csv *vwrite,output(1,1), output(1,2) (2(F16.7,’,’)) *cfclose fini /exit

It is recommended that the files for this example are to be placed in a folder called DA MAPDL Example within your ANSYS Inc folder. If you choose not to use this folder, the paths used in the XML definition file to locate the python scripts will need to be modified.

Creating the XML Definition File The XML definition file is set up to create an Attribute Group object for the user to browse to the macro, and a DA Result object to indicate which column from the CSV file to present results for. It will run two scripts. Upon solve, the macro file defined by the user in the Attribute Group will be run by Mechanical APDL and the CSV file created. Upon evaluate, values will be read from the appropriate column in the CSV file and displayed in the Details view of the Design Assessment system.

MAPDL.xml

MAPDL Macro File Browse <Application PropType=»string»>All 256

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Examples of Design Assessment Usage

Column Int <Application PropType=»string»>All 1,100 1 Select MAPDL File By Browsing «>100 <Solve PropType=»string»>%DAPROGFILES%\Ansys Inc\DA MAPDL Example\MADPL_S.py <Evaluate PropType=»string»>%DAPROGFILES%\Ansys Inc\DA MAPDL Example\MAPDL_E.py 1 0 Select Result Column Number Input «>101 Elemental Scalar No Units

The Attributes section defines two DAAttributes: 1st Attribute: Enables the users to browse to the Macro file, Attribute Id = 100: • Named “MAPDL Macro File” • Browse control type • Applies to all geometry • Validates for a maximum length of 256 characters • No default entry 2nd Attribute: Enables the users to select a column in the CSV file, Attribute Id = 101: • Named “Column” • Integer entry type • Applies to all geometry • Validates to check the value is between 1 and 100 (inclusive) • Defaults to a value of 1 In the AttributeGroups section, we define a single Attribute Group object. As we have only one, the GroupType and GroupSubtype fields are effectively redundant, but ought to be entered. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Design Assessment • Allow the users to browse to the Macro file, Attribute Id = 110000: – Type = Select MAPDL File – SubType = By Browsing – Include Attribute with Id = 100 This becomes the following object in the Mechanical application:

In the DAScripts section we set the path to the scripts to be run on Solve and on Evaluate. In this case we use the %DAPROGFILES% option to direct the program to the Program Files folder, wherever it’s defined locally. The scripts in this case are called MAPDL_S.py and MAPDL_E.py. We want to permit Design Assessment results and prevent combination results In the Results section, we define a single DAResult object. As we have only one, the GroupType and GroupSubtype fields are effectively redundant, but ought to be entered. • Allow the users to browse to the Macro file, Attribute Id = 110000: – Type = Select Result Column – SubType = Number Input – Include Attribute with Id = 101 – DisplayType is set to show results per element – DisplayStyle is set to show a single, scalar, result – There are no units associated to this result, we’ll set this in the python script This becomes the following object in the Mechanical application:

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Examples of Design Assessment Usage

Creating the Script to be Run on Solve, MAPDL_S.py When the user selects “solve” the python script will: 1. Find out what macro file has been selected a. Display a message to the Solver Script Output if more than one attribute group is defined 2. Obtain selected upstream solution data a. Display a message to the Solver Script Output if more than one upstream system is entered 3. Run the macro with Mechanical APDL a. It is assumed that the macro will write data out to a CSV file so it can be read at the evaluate stage b. Display the output from running the macro as the Solver Output import os DA = DesignAssessment def runDADemoSolve(): #1.a — display message if DA.AttributeGroupCount != 1: print «Only one Attribute Group should be entered» #2.a — Display message if DA.SolutionSelections()[0].SolutionCount != 1: print «Only one upstream solution should be entered» #1 — Get the macro path MAPDLMacro = DA.AttributeGroups()[0].Attribute(«MAPDL Macro File»).ValueAsString SolPath = DA.SolutionSelections()[0].SolutionByRow(1).ResultFilePath #2 — Form the command line strings SolPath_Output = «Macro.out» SolTime_ARG2 = str(DA.SolutionSelections()[0].SolutionByRow(1).Time) BatchArgs = » -par1 file -par2 » + SolTime_ARG2 #2 — Run the solve with MAPDL #Change to the path where the results are kept os.chdir(SolPath.rstrip(‘file.rst’)) #Run MAPDL DA.Helper.RunMAPDL(MAPDLMacro,SolPath_Output,BatchArgs)

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Using Design Assessment

#2.b — Display the output DA.Helper.ReplaceSolverOutputFile(SolPath_Output) runDADemoSolve()

Creating the Script to be Run on Evaluate All Results, MAPDL_E.py When the user selects “evaluate” the python script will: 1. Read the CSV file a. Identify the location of the CSV file; this is stored in the upstream result path b. Convert it to a dictionary based on the element ID; each entry of the dictionary is a list of values for each column in the file i.

Read each line of the file

ii. Split using the commas as the delimiter iii. Convert the text into numeric values iv. Store the values in an array v. Add the array into the dictionary based on the ID 2. For each DAResult create a DAResultSet. Each DAResultSet will display a value for each element a. Find the column to use based on the users entry b. Create the DAResultSet c. The value is found by looking it up in the dictionary with the given element ID #import System DA = DesignAssessment #1.b.iii — Define a rountine to convert text to either a real or integer number. def convertStr(s): #remove the comma s = s.translate(None,’,’) #If a value exists if len(s) > 0: #Try to convert to an integer try: ret = int(s) except ValueError: #couldn’t convert to an integer, try a real number try: ret = float(s) except ValueError: #couldn’t convert to a number, set to large value #(makes Mechanical display translucent) ret = 1.7976931348623157e+308 return ret #1.b — Define seperate routine to convert CSV to a dictionary for in-memory access. def CSVToDictionary(PathAndFile): #Define a dictionary IDToDataDict = {}; #Open the file CSVFile = open(PathAndFile,»r»)

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Examples of Design Assessment Usage

#1.b.i — step through the file, line by line. for line in CSVFile: #1.b.ii — Split into an array of words. words = line.split(«,») #Get the first column, this is the identifier (e.g. Element or Node ID) ID = convertStr(words[0]) #1.b.iv — All other data becomes a list of numbers Data = [] for i in range(len(words)-1): Data.append(convertStr(words[i+1])) #1.b.v — Assign the list to the identifier in the dictionary IDToDataDict[ID] = Data #Close the file and return the dictionary. CSVFile.close() return IDToDataDict def runDADemo(): #1.a — Find where the CSV fle is stored. SolPath = DA.SolutionSelections()[0].SolutionByRow(1).ResultFilePath CSVPath = SolPath.rstrip(‘file.rst’) + «data.csv» #1.b — Call the function to convert the CSV file into a dictionary IDToDataDict = CSVToDictionary(CSVPath) #2 — access each DA Result object in the available results for DAResult in DA.DAResults(): #2.a — Find the column to look up in the CSV data ColIndex = DAResult.Attribute(«Column»).ValueAsInt — 1 #2.b — Create a result set to display the results using. #We know that in this case it’s scalar and element based. DAResultSet = DAResult.CreateDAResultSet(«Scalar»,»Elemental») #2.c — For each element set the value. for Element in DA.MeshData.Elements(): DAResultSet.SetElementalValue(Element.Id,1,IDToDataDict[Element.Id][ColIndex]) runDADemo()

Expanding the Example The example given was for a scalar, elemental result. However, if the result required was say a nodal, vector based result, then this example could easily modified by changing a few lines in the evaluate script. Assume that the CSV file contains a first column for the node Id, then 3 columns for X, Y, Z components of the vector. Then, these lines where it previously used SetElementValue: DAResultSet = DAResult.CreateDAResultSet(«Scalar»,»Elemental») #2a — For each element set the value. for Element in DA.MeshData.Elements(): DAResultSet.SetElementalValue(Element.Id,1,IDToDataDict[Element.Id][ColIndex])

Would change to the following, using the SetNodalValue function: DAResultSet = DAResult.CreateDAResultSet(«Vector»,»Nodal») #2a — For each element set the value. for Node in DA.MeshData.Nodes(): DAResultSet.SetNodalValue(Node.Id,1,IDToDataDict[Node.Id][0])

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Using Design Assessment DAResultSet.SetNodalValue(Node.Id,2,IDToDataDict[Node.Id][1]) DAResultSet.SetNodalValue(Node.Id,3,IDToDataDict[Node.Id][2])

Alternatively, if the CSV file was always of this NodeId, X, Y, Z format, and given that this is converted into a dictionary of arrays using the Node Id as the key, then the SetNodalValues function could be used instead: DAResultSet = DAResult.CreateDAResultSet(«Vector»,»Nodal») #2a — For each element set the value. for Node in DA.MeshData.Nodes(): DAResultSet.SetNodalValues(Node.Id,IDToDataDict[Node.Id])

Using Design Assessment to Calculate Complex Results, such as Those Required by ASME The purpose of this example is to illustrate how to Design Assessment can be used to calculate results that are beyond the capabilities of the standard user defined result; for example those given in codes of practice such as those from ASME.

Creating the XML Definition File The XML definition file defines 4 attributes; 3 are material constants and are to be grouped under a single Attribute Group. The final one is the result set, used to obtaining intermediary results at a given time. The attribute section of the XML definition file is defined as:

Const 1 Double <Application PropType=»string»>All -100,100 0.247 Const 2 Double <Application PropType=»string»>All -100,100 2.2 Const 3 Double <Application PropType=»string»>All -100,100 0.25 Set Number Int <Application PropType=»string»>All 1,100 1

And to group the 3 material constants together we have an Attribute Group. Defining these in the Attribute Group means that the values can be parameterized if required. This enables a range of coefficients and associative results obtained by running Design Explorer.

ASME VIII Division 3 High Pressure Vessels Material Constants

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Examples of Design Assessment Usage

«>101,102,103

The solve and evaluate files are to reside in the user files folder so that they can be easily distributed with the project. All of the processing is to be performed during the evaluate script, so no intermediary files are created to pass data from the solve process to the evaluate process. Combination results are not required and we have no additional system based selection data to define.

<Solve PropType=»string»>%DAUSERFILES%\DA-AFT-012_m1-S_empty.py <Evaluate PropType=»string»>%DAUSERFILES%\DA-AFT-012_m1-E_v3_ST.py 1 0

In the final section, 3 types of DAResults are defined based on the following equations: X — Based on 3 entered constants, plus principal and Von Mises stress

        +   +   −         =
    +         

(56)

Damage — The damage value: change in plastic strain divided by X

 −  =  , !»#$%&’  , !»#$%&’ , !()&*+$ 

(57)

Damage Sum — Accumulative damage; i.e. sum of current and previous Damage values for each result set. The results section of the XML definition file appears as follows:

ASME VIII Division 3 High Pressure Vessels Value X «>110 ElementNodal Scalar Stress ASME VIII Division 3 High Pressure Vessels Damage «>110 ElementNodal Scalar No Units ASME VIII Division 3 High Pressure Vessels Culmative Damage «> ElementNodal Scalar No Units

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Creating the Script to be Run on Evaluate The script first imports the python math function and defines some constants. import math DA = DesignAssessment DA.OutputDeprecatedWarnings(True) UpstreamSolution = DesignAssessment.SolutionSelections()[0].Solutions()[0]

Three routines “EvaluateValueX”, “EvaluateDamage”, and “EvaluateCulmativeDamage”, are defined for performing the calculations for each equation. These are followed with definitions for two additional routines, “Plot” to plot the results and “EvaluateAllResults” to control the evaluate process. The following sections look at each of these routines, starting from the “EvaluateAllResults” entry point. EvaluateAllResults EvaluateDamage EvaluateCulmativeDamage Plot

EvaluateAllResults After defining a dictionary to store the element nodal based results, this function creates a new result with part of the required equation and then defines which set to obtain the results from. Then, looping through each element and its nodes, it calculates the part of the equation that is not possible with the standard Mechanical equations and assigns it into the dictionary for the given node and element Id. def EvaluateValueX(Set, Const1, Const2, Const3): XValues = {} #key = element node id tuple, #data = values array. SolRes = UpstreamSolution.CreateSolutionResult(«»,str(Const2/(1+Const3))+»*((((s1+s2+s3)/(3*seqv))-\ (1/3)))»,»Stress») SolRes.ResultSet = Set for Element in DA.MeshData.Elements(): for Node in Element.Nodes(): SolResValue = SolRes.ElementNodalValues(Element.Id,Node.Id) XValue = Const1 * math.exp(SolResValue[0]) XValues[Element.Id,Node.Id] = XValue return XValues

EvaluateDamage This routine calls the “EvaluateValueX” function to obtain the X Values then creates 2 solution results for the plastic strain results for this and, if one exists, the previous set. A dictionary is created for the element nodal results being generated and this is populated by performing the required calculation. def EvaluateDamage(Set, Const1, Const2, Const3): XValues = EvaluateValueX(Set, Const1, Const2, Const3) StrainRes = UpstreamSolution.CreateSolutionResult(«»,»EPPLEQV_RST»,»Strain») StrainRes.ResultSet = Set PrevStrainRes = UpstreamSolution.CreateSolutionResult(«»,»EPPLEQV_RST»,»Strain») if (Set >= 2): PrevStrainRes.ResultSet = Set — 1 DamageValues = {}

#key = element node id tuple, #data = values array.

for Element in DA.MeshData.Elements(): for Node in Element.Nodes(): S1 = StrainRes.ElementNodalValues(Element.Id,Node.Id)[0]

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Examples of Design Assessment Usage S2 = 0 if (Set >= 2): S2 = PrevStrainRes.ElementNodalValues(Element.Id,Node.Id)[0] XValue = XValues[Element.Id,Node.Id] DamageValues[Element.Id,Node.Id] = (S1 — S2) / XValue return DamageValues

EvaluateCulmativeDamage This routine creates a dummy result to obtain the number of result sets. Then, for each set, calls the “EvaluateDamage” function summing the results into a dictionary of element nodal results called CulmativeDamage. def EvaluateCulmativeDamage(Const1, Const2, Const3): DummyRes = UpstreamSolution.CreateSolutionResult(«»,»EPPLEQV_RST»,»Strain») CulmativeDamage = {} for Set in range(DummyRes.ResultSetCount): DamageValues = EvaluateDamage(Set,Const1, Const2, Const3) if (Set > 1): for Element in DA.MeshData.Elements(): for Node in Element.Nodes(): CulmativeDamage[Element.Id,Node.Id] = CulmativeDamage[Element.Id,Node.Id] +\ DamageValues[Element.Id,Node.Id] else: CulmativeDamage = DamageValues return CulmativeDamage

Plot This routine creates a new result for this DAResult object and then loops over each element and node setting the value obtained from the passed in dictionary. def Plot(DAResult, ValuesDictionary): ResultSet = DAResult.CreateDAResultSet() for Element in DA.MeshData.Elements(): for Node in Element.Nodes(): Value = ValuesDictionary[Element.Id,Node.Id] ResultSet.SetElementNodalValue(Element.Id,Node.Id,1,Value)

When the script is run, a contour plot is generated for each DA Result.

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Using Design Assessment to Perform Further Results Analysis for an Explicit Dynamics Analysis The purpose of this example is to illustrate how Design Assessment can be used to perform further processing, presenting results in a text file and graphically. In this example, algorithms are written in python to identify which elements form fragments of the geometry following an Explicit Dynmaics analysis.

Creating the XML Definition File The XML definition file defines a number of DA Results. All of the processing is to be performed during the evaluate script. This approach means that different levels of damage can be used for the fragment identification within one analysis. This would not be the case if the fragments were determined at the solve stage, but determining fragments at solve stage could be more efficient. Six different results are set up as follows: • Element Results: – Hide Damaged Elements – Show User Defined Result • Fragment Results: – Number of Elements in Fragment – Volume of Fragment

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Examples of Design Assessment Usage – Mass of Fragment – Average Damage in Fragment Each can have failure based upon Failure Threshold or Status, with a numeric limit, and all but the Show User Defined Result can optionally output text to the solver output file. These are attributes 90, 91, and 92 respectively. The Show User Defined Result also has additional input to enable the user to choose the result to display. The results section of the XML definition file is as follows:

Element Hide Damaged Elements «>90,91,92 Element Show User Defined Result «>90,91,103,105,106,107 Fragment Number of Elements in Fragment «>90,91,92 Fragment Volume of Fragment «>90,91,92 Fragment Mass of Fragment «>90,91,92 Fragment Average Damage in Fragment «>90,91,92 Fragment Kinetic Energy Of Fragment «>90,91,92 Fragment Characteristic Length of Fragment «>90,91,92 Fragment CL Increase «>90,91,92 Fragment Momentum «>90,91,92 Fragment Origin «>90,91,92 Fragment

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Using Design Assessment

Centre «>90,91,92 Fragment AverageSpeed «>90,91,92

Creating the Script to be Run on Evaluate The script first calls the function runDADemo. This loops over each result and, based on the type and subtype it calls an appropriate sub function to perform the calculation. In the case of fragmentation results, it first calls a function, IdentifyFragments, to create a dictionary of fragments. The fragment dictionary created is a data collection that contains the fragment number for each Element Id. This dictionary is passed to each function so it can be used for the fragment result calculation. An example of this fragment result calculation is VolumeOfFragment: def VolumeOfFragment(SortedDict, DAResult, FragmentDict, NodalMass): print » » print «Volume of Fragment» print » ________________________________» print «|Fragment | Volume(m^3) |» print «+————+——————-+» UpstrResDensity = UpstreamSolution.CreateSolutionResult(«»,»DENSITY»,»No Units») UpstrResDensity.IntegrationMethod = «unAveraged» # unaveraged because summing indiviual values # and taking an average afterwards. Density = 0 NodeCounter = 0 FragmentDataDict = {} #key = elementid, data = mass FragmentDataDict2 = {} NodesProcessed = {} for ElementID in FragmentDict.keys(): NodeList = DA.MeshData.ElementById(ElementID).NodeIds() for NodeID in NodeList: if NodesProcessed.has_key(NodeID): continue else: Fragment = FragmentDict[ElementID] Mass = NodalMass[NodeID] # uses NodalMass dictionary from NodalMassFunc if FragmentDataDict.has_key(Fragment): FragmentDataDict[Fragment] += Mass else: FragmentDataDict[Fragment] = Mass NodesProcessed[NodeID] = 0 Density += UpstrResDensity.ElementNodalValues(ElementID, NodeID)[0] # sum all of the # densities NodeCounter += 1 # Count the number of nodes which have been processed Index = 1 Total = 0 for Key in FragmentDataDict.keys(): TVol = (FragmentDataDict[Key])/(Density/NodeCounter) # divide total density by the number # of nodes Text = «Fragment :» + str(Index) + » has a Volume of » + str(TVol) + » m^3″ FragmentDataDict2[Key] = TVol Index += 1 Total += TVol NewResultData = DAResult.CreateDAResultSet(«Scalar»,»Elemental») for ElementId in FragmentDict: NewResultData.SetElementalValue(ElementId, 1, FragmentDataDict2[FragmentDict[ElementId]]) FragmentDataDict2 = Sort(SortedDict, FragmentDataDict2)

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Examples of Design Assessment Usage for Fragment in FragmentDataDict2: print «| » + str(Fragment) + » | » + str(‘%.3e’%FragmentDataDict2[Fragment]) +\ » |» print «+————+——————-+» print «| Total | » + str(‘%.3e’%Total) +» |» print «|____________|___________________|» print » » print » » print » «

The result can then be displayed:

Expanding the Example Additional results could be obtained on a per fragment basis.

Using Design Assessment to Obtain Composite Results Using Mechanical APDL Along with the example Using Design Assessment to Obtain Results from Mechanical APDL (p. 1260), the purpose of this example is to illustrate how to run Mechanical APDL in batch mode using Design Assessment, and how to present the results within the Workbench environment — see MAPDL command reference for further information. Unlike Using Design Assessment to Obtain Results from Mechanical APDL (p. 1260) which is more generic, this example is set up to run a specific script and obtain specific results; therefore the interface can be more targeted and offer better guidance to the user. In this example the input file for Mechanical APDL is dynamically generated by the python script. This in turn calls a fix macro with various given parameters as determined from the DA Result objects added to the model. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Using Design Assessment The macro file that is run, named LayerMultiPly.mac, is as follows: ! INPUT: ! Input arguments relate to the failure criteria for one material ! ARG1 Type of result, e.g. ‘fail’ ! ARG2 Subtype of the result, e.g. ’emax’ ! ARG3 1 for nodal or 0 for elemental based results ! ARG4 1 based layer number ! ! OUTPUT: critical layer and Strength Ratio will be written to defined CSV file ! /post1 /delete,CSVFile_Directory(1),csv /cwd,Current_Directory(1) Type = ARG1 SubType = ARG2 DisplayType = ARG3 LayerNum = ARG4 file,SYS_Directory(1),rst set,last rsys,solu

! set the last set into memory

! set the failure criteria FCTYP,add,all tblist,,1 ! set the layer layer,LayerNum *if,DisplayType,eq,0,then ! select the elements esel,s,ename,,181 ! get the number of elements that we need to loop over *get,ecount,elem,0,count ! make sure some elements are selection *if,ecount,lt,1,then *MSG,ERROR THERE ARE NO ELEMENTS SELECTED FOR FAILURE CHECKING *endif ! dimension the output arrays *dim,output,arra,ecount,2 etab,bob,Type,SubType !get elemental results curre = 0 *do,i,1,ecount curre = ELNEXT(curre) ! get the element number output(i,1) = curre *get,output(i,2),etab,1,elem,curre *enddo *cfopen,CSVFileScratch_Directory(1),csv *vwrite,output(1,1),output(1,2) (F10.0,’,’,F16.3) *cfclose *elseif,DisplayType,eq,1,then ! select the elements esel,s,ename,,181 nsle

! get the number of nodes that we need to loop over

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Examples of Design Assessment Usage *get,ncount,node,0,count ! make sure some nodes are selection *if,ncount,lt,1,then *MSG,ERROR THERE ARE NO NODES SELECTED FOR FAILURE CHECKING *endif *dim,output2,arra,ncount,2 curre = 0 *do,i,1,ncount curre = NDNEXT(curre) output2(i,1) = curre *get,output2(i,2),node,i,Type,SubType *enddo *cfopen,CSVFileScratch_Directory(1),csv *vwrite,output2(1,1),output2(1,2) (F10.0,’,’,F16.3) *cfclose *endif

It is recommended that the files for this example are to be placed in your user_files folder.

Creating the XML Definition File The XML definition file is set up so that there are no attribute groups, and where appropriate the layer number, display types, and an option to invert the value attributes are included in the DA Result definitions.

The failure.xml file

Layer Int <Application PropType=»string»>All 1,1000000 1 Display DropDown <Application PropType=»string»>All Elemental,Nodal Elemental Inverse DropDown <Application PropType=»string»>All Yes,No Yes <Solve PropType=»string»>%DAUSERFILES%\SolveFailure.py <Evaluate PropType=»string»>%DAUSERFILES%\EvaluateFailure.py 1 0 <SelectionExtra PropType=»vector<string>»> Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Layer Dependant Failure Maximum strain «>101,100 Layer Dependant Failure Maximum stress «>101,100 Layer Dependant Failure Tsai-Wu strength index «>101,100,102 Layer Dependant Failure Inverse of Tsai-Wu strength ratio index «>101,100,102 Layer Dependant Failure Hashin fiber failure «>101,100,102 Layer Dependant Failure Hashin matrix failure «>101,100,102 Layer Dependant Failure Puck fiber failure «>101,100,102 Layer Dependant Failure Puck inter-fiber (matrix) failure «>101,100,102 Layer Dependant Failure LaRc03 fiber failure «>101,100,102 Layer Dependant Failure LaRc03 matrix failure «>101,100,102 Layer Dependant Failure LaRc04 fiber failure «>101,100,102 Layer Dependant Failure LaRc04 matrix failure «>101,100,102 Maximum Failure Criteria Layer «> Elemental

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Examples of Design Assessment Usage

Maximum Failure Criteria Failure Criteria «> Elemental Maximum Failure Criteria Value «>102 Elemental

Creating the Script to be Run on Solve, SolveFailure.py This is not used as everything is run on the fly, so it is just a simple print statement to say as such.

Creating the Script to be Run on Evaluate All Results, EvaluateFailure.py Example 1 covers some aspects of this evaluate function. For example reading the CSV file into a dictionary. The following sections concentrate on the new techniques used here: Using a Dictionary to Avoid a Long if/elif/else Statement. Writing the MADPL .inp File from Within Design Assessment Running Mechanical APDL Multiple Times

Using a Dictionary to Avoid a Long if/elif/else Statement. At the beginning of the script it sets up a dictionary matching the XML Type and XML SubType to the Type and SubType of result required in Mechanical APDL: TypeSubTypeDict = {} TypeSubTypeDict[«Layer TypeSubTypeDict[«Layer TypeSubTypeDict[«Layer TypeSubTypeDict[«Layer TypeSubTypeDict[«Layer TypeSubTypeDict[«Layer TypeSubTypeDict[«Layer TypeSubTypeDict[«Layer TypeSubTypeDict[«Layer TypeSubTypeDict[«Layer TypeSubTypeDict[«Layer TypeSubTypeDict[«Layer

Dependant Dependant Dependant Dependant Dependant Dependant Dependant Dependant Dependant Dependant Dependant Dependant

Failure»,»Maximum strain»] = «fail»,»emax» Failure»,»Maximum stress»] = «fail»,»smax» Failure»,»Tsai-Wu strength index»] = «fail»,»twsi» Failure»,»Inverse of Tsai-Wu strength ratio index»] = «fail»,»twsr» Failure»,»Hashin fiber failure»] = «fail»,»hfib» Failure»,»Hashin matrix failure»] = «fail»,»hmat» Failure»,»Puck fiber failure»] = «fail»,»pfib» Failure»,»Puck inter-fiber (matrix) failure»] = «fail»,»pmat» Failure»,»LaRc03 fiber failure»] = «fail»,»l3fb» Failure»,»LaRc03 matrix failure»] = «fail»,»l3mt» Failure»,»LaRc04 fiber failure»] = «fail»,»l4fb» Failure»,»LaRc04 matrix failure»] = «fail»,»l4mt»

TypeSubTypeDict[«Maximum Failure Criteria»,»Layer»] = «FCMX»,»lay» TypeSubTypeDict[«Maximum Failure Criteria»,»Failure Criteria»] = «FCMX»,»fc» TypeSubTypeDict[«Maximum Failure Criteria»,»Value»] = «FCMX»,»val»

These can then be easily looked up using: MAPDLKeys = TypeSubTypeDict[str(DAResult.XmlType),str(DAResult.XmlSubType)]

MAPDLKeys can then be accessed like a regular array; i.e. MAPDLKeys[0] will return “fail” or “FCMX” appropriately.

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Writing the MADPL .inp File from Within Design Assessment In this case we want to write the input file for Mechanical APDL from within Design Assessment so that multiple paths can be set, etc., without having to use command line parameters. Most of the common functionality is extracted to the macro file so the input file mainly just sets up these parameters. def CreateMAPDLInputFile(MAPDLKeys,Layer,Display): ArgList = str(«,'» + MAPDLKeys[0]) + «‘,'» + str(MAPDLKeys[1]) + «‘,» + str(Display) + «,» + \ str(Layer) currentdirectory = os.getcwd() RunMapdlFile = open(TempMAPDLRunFilePath, «w») WriteLine(RunMapdlFile,»/batch») WriteLine(RunMapdlFile,»*DIM,SYS_Directory,string,248″) RSTFileLoc = DesignAssessment.SolutionSelections()[0].SolutionByRow(1).ResultFilePath.rstrip(‘.rst’) WriteLine(RunMapdlFile,»‘SYS_Directory(1)’ = » + «‘» + RSTFileLoc + «‘») WriteLine(RunMapdlFile,»*DIM,CSVFile_Directory,string,248″) WriteLine(RunMapdlFile,»‘CSVFile_Directory(1)’ = » + «‘» + DesignAssessment.Helper.ResultPath + \ «\\TempRes» + «‘») WriteLine(RunMapdlFile,»*DIM,CSVFileScratch_Directory,string,248″) WriteLine(RunMapdlFile,»‘CSVFileScratch_Directory(1)’ =» + «‘» + currentdirectory + «\\TempRes» + \ «‘») WriteLine(RunMapdlFile,»*DIM,Current_Directory,string,248″) WriteLine(RunMapdlFile,»‘Current_Directory(1)’ =» + «‘» + currentdirectory + «‘») WriteLine(RunMapdlFile,»*USE,LayerMultiPly.mac» + ArgList) WriteLine(RunMapdlFile,»fini») WriteLine(RunMapdlFile,»/exit») RunMapdlFile.close()

Running Mechanical APDL Multiple Times Mechanical APDL is run repeatedly for each DA Result object. In each case, the CSV file is read and the results displayed. In-line if statements are used to determine, among other things, if the value is to be inverted and what the value is if it is inverted. def runStressEvaluate(DesignAssessment): #Change to the result path as the local folder, to save passing in long file names to the MAPDL solve originaldir = os.getcwd() os.chdir(DesignAssessment.Helper.ResultPath) # Make sure the mapdl macro is in this directory shutil.copy2(DesignAssessment.Helper.UserFilesDirectory + «\\LayerMultiPly.mac», \ DesignAssessment.Helper.ResultPath) # For now just assume one upstream but could make the code generic if required if (DesignAssessment.SolutionSelections()[0].SolutionCount > 1): print «only the first solution in the solution selection object will be used» for DAResult in DesignAssessment.DAResults(): #Identify the type and subtype to be passed into MAPDL MAPDLKeys = TypeSubTypeDict[str(DAResult.XmlType),str(DAResult.XmlSubType)] print MAPDLKeys #in-line if / else statements, format of N = ValueA if statement [is true] else [N =] ValueB. Layer = 0 if (DAResult.Attribute(«Layer») == None) else DAResult.Attribute(«Layer»).ValueAsInt Display = «Elemental» if (DAResult.Attribute(«Display») == None) else \ DAResult.Attribute(«Display»).ValueAsString Inverse = False if (DAResult.Attribute(«Inverse») == None) else \

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Examples of Design Assessment Usage DAResult.Attribute(«Inverse»).ValueAsString == «Yes» #Create the results temp file by running a post script with MAPDL if Display == «Elemental»: CreateMAPDLInputFile(MAPDLKeys,Layer,0) elif Display == «Nodal»: CreateMAPDLInputFile(MAPDLKeys,Layer,1) #Run MAPDL DesignAssessment.Helper.RunMAPDL(TempMAPDLRunFilePath,»out.lis»,»/minimise») DesignAssessment.Helper.ReplaceSolverOutputFile(«out.lis») #Read the results from the temp file to memory. IDToDataDict = CSVToDictionary(DesignAssessment.Helper.ResultPath + «tempres.csv») #Present the results #Elemental if Display == «Elemental»: DAResultSet = DAResult.CreateDAResultSet(«Scalar»,»Elemental») for Element in DesignAssessment.MeshData.Elements(): Value = 1/max(IDToDataDict[Element.Id][0],0.01) if Inverse else \ IDToDataDict[Element.Id][0] DAResultSet.SetElementalValue(Element.Id,1,Value) #Nodal elif Display == «Nodal»: DAResultSet = DAResult.CreateDAResultSet(«Scalar»,»Nodal») for Node in DesignAssessment.MeshData.Nodes(): Value = 1/max(IDToDataDict[Node.Id][0],0.01) if Inverse else IDToDataDict[Node.Id][0] DAResultSet.SetNodalValue(Node.Id,1,Value) os.chdir(originaldir)

Expanding the Example The example could be expanded to perform combinations of results and factor the values based on the coefficient provided for the upstream system.

Using Design Assessment to Access and Present Multiple Step Results This example shows how to access upstream results from multiple time points and to create a new result with a different number of time points as defined in the user object.

Creating the XML Definition File The following XML definition file defines attributes for a DA Result object that allow you to specify a particular row in the Solution Selection, an expression and units, along with the number of substeps for which to present results.

Row Number Int <Application PropType=»string»>All 1,50 1 No Units Expression Text <Application PropType=»string»>All 20 Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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SX No Units Number of Substeps Int <Application PropType=»string»>All 1,1000 1 No Units Units DropDown <Application PropType=»string»>All No Units,Stress,Distance,Strain,Force,Moment,Rotation, Angular Acceleration,Angular Velocity,Velocity,Acceleration,Temperature,Pressure,Voltage, Energy,Volume,Area,Current,Heat Rate,Current Density,Power,Heat Generation,Magnetic Flux <Solve PropType=»string»>%DAUSERFILES%\loadsteps_S.py <Evaluate PropType=»string»>%DAUSERFILES%\loadsteps.py 1 1 Load Steps Single «>10,11,12,13

Creating the Script to be Run on Evaluate The below code snippet shows it looping though the creation of a number of these sets, then setting the ResultTimeFrequency value for it to use for each result set in the display. while substepvalue <= EndTime: #Create a DA Result set for each substep NewResultData = DAResult.CreateDAResultSet(UpstreamResult.DisplayStyle,»Nodal») #Set the substep value NewResultData.SubstepValue = substepvalue #Set the Solution result to obtain results at this time UpstreamResult.ResultTimeFrequency = NewResultData.SubstepValue #Loop over elements for Element in DesignAssessment.MeshData.Elements(): ElementID = Element.Id #Loop over nodes for Node in Element.Nodes(): NodeID = Node.Id #Set the value for each Node in the Values Dictionary ValueDict[NodeID] = UpstreamResult.NodalValues(NodeID)[0] #Loop over Nodes in the mesh for Node in DesignAssessment.MeshData.Nodes(): NodeID = Node.Id #Set the value at the node to be the value set for that node in the Values Dictionary NewResultData.SetNodalValue(NodeID, 1, ValueDict[NodeID]) #increment substep value substepvalue += increment

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Examples of Design Assessment Usage

Using Design Assessment to Perform an Explicit-to-Implicit Sequential Analysis The purpose of this example is to illustrate how Design Assessment can be used to write Mechanical APDL commands to perform an explicit-to-implicit sequential analysis. Relevant data is obtained from the Explicit Dynamics analysis, and Design Assessment then writes Mechanical APDL commands to a file for execution in the implicit analysis within Workbench.

Note This method is currently limited to cases where there is no change in mesh topology between the start of both the explicit and implicit analyses.

Creating the XML Definition File An XML file is needed to specify the script that will be called on evaluate to read files from the explicit results, use those results to initialize the implicit model, then view the results using the Mechanical APDL post processor.

Expression Text <Application PropType=»string»>All 20 SX No Units <Solve PropType=»string»>%DAUSERFILES%\Solve.py <Evaluate PropType=»string»>%DAUSERFILES%\Evaluate.py 1 1 Explicit Explicit «>11

Creating the Solve Script The main stages involved in the process for Solids are: 1. Enter the pre-processor /prep7 2. Initialize model with deformations from end of the explicit analysis 3. Specify reduced element integration 4. Enter solution processor 5. Initialize implicit model with stresses from end of the explicit analysis

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Using Design Assessment 6. Initialize implicit model with plastic strains from end of the explicit analysis The first thing to consider is the deformation at the end of the explicit analysis. Deformation is a nodal result and thus deformation components are obtained at every node. UpstreamSolution = DesignAssessment.SolutionSelections()[0].SolutionByRow(1) UpstreamResult1 = UpstreamSolution.CreateSolutionResult(«»,»UVECTORS»,»Distance») #write «Text» to solver output file» DesignAssessment.Helper.AppendToSolverOutputFile(Text) for Node in DesignAssessment.MeshData.Nodes(): NodeID = Node.Id #set variables to components of deformation vector result U1 = UpstreamResult1.NodalValues(NodeID)[0] U2 = UpstreamResult1.NodalValues(NodeID)[1] U3 = UpstreamResult1.NodalValues(NodeID)[2] print str(NodeID) + «: » +str(U3) #write commands to redefine node locations Text = «*GET, X_CO, NODE, » + str(NodeID) +», LOC, X,\n\ *GET, Y_CO, NODE, » + str(NodeID) + «, LOC, Y,\n\ *GET, Z_CO, NODE, » + str(NodeID) + «, LOC, Z,\n\ N, «+str(NodeID) + «, X_CO + («+ str(U1) +»), Y_CO + (» + str(U2) + «), Z_CO + (» + str(U3)+»)\n» DesignAssessment.Helper.AppendToSolverOutputFile(Text)

DesignAssessment.Helper.AppendToSolverOutputFile(Text) writes whatever is stored in the variable Text to the Solver Output File of the Design Assessment system. The Mechanical APDL commands then are written in the following format: *GET, *GET, *GET, N, 1,

X_CO, NODE, 1, LOC, X, Y_CO, NODE, 1, LOC, Y, Z_CO, NODE, 1, LOC, Z, X_CO + (0.0159664358944), Y_CO + (-0.478581756353), Z_CO + (4.01744182454e-05)

*GET, *GET, *GET, N, 2,

X_CO, NODE, 2, LOC, X, Y_CO, NODE, 2, LOC, Y, Z_CO, NODE, 2, LOC, Z, X_CO + (0.0159850046039), Y_CO + (-0.478512704372), Z_CO + (2.13666535274e-05)

*GET, *GET, *GET, N, 3,

X_CO, NODE, 3, LOC, X, Y_CO, NODE, 3, LOC, Y, Z_CO, NODE, 3, LOC, Z, X_CO + (0.0159850046039), Y_CO + (-0.478512704372), Z_CO + (-2.13666735362e-05)

These commands obtain the original location of the nodes from the mesh of the implicit analysis, add the deformation of those nodes from the end of the explicit analysis, and redefine the position of the nodes to the new location. Please refer to the Mechanical APDL Command Reference for more information on the specific Mechanical APDL commands. It is now necessary to write Mechanical APDL commands to initialize the model with the stresses and plastic strains from the end of the explicit analysis. The Mechanical APDL command used for this is INISTATE. Solution results are created for each of the results that are of interest. The integration method is set to unaveraged because the result for the element is required, as opposed to the result at the node. Using an unaveraged integration method means that all of the nodes on one element have the same value. It is therefore only necessary to get the value at one of the nodes. Element.Nodes()[0].Id gets the Node ID of the first node in the array of nodes for the current element. The results are then obtained for this node. #stress components SX = UpstreamSolution.CreateSolutionResult(«»,»SX»,»No Units»)

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Examples of Design Assessment Usage SY = UpstreamSolution.CreateSolutionResult(«»,»SY»,»No Units») SZ = UpstreamSolution.CreateSolutionResult(«»,»SZ»,»No Units») SXY = UpstreamSolution.CreateSolutionResult(«»,»SXY»,»No Units») SYZ = UpstreamSolution.CreateSolutionResult(«»,»SYZ»,»No Units») SXZ = UpstreamSolution.CreateSolutionResult(«»,»SXZ»,»No Units») #specify unaveraged integration method SX.IntegrationMethod = («unaveraged») SY.IntegrationMethod = («unaveraged») SZ.IntegrationMethod = («unaveraged») SXY.IntegrationMethod = («unaveraged») SYZ.IntegrationMethod = («unaveraged») SXZ.IntegrationMethod = («unaveraged») for Element in DesignAssessment.MeshData.Elements(): #get ID of first node in element FirstNodeId = Element.Nodes()[0].Id #write commands to initialize stress Text = «INISTATE, SET, DTYP, STRESS\nINISTATE, DEFINE, » + str(Element.Id) + \ «, all,all,all, » + str(SX.ElementNodalValues(Element.Id, FirstNodeId)[0]) + «, » \ + str(SY.ElementNodalValues(Element.Id, FirstNodeId)[0]) + «, » \ + str(SZ.ElementNodalValues(Element.Id, FirstNodeId)[0]) + «, » \ + str(SXY.ElementNodalValues(Element.Id, FirstNodeId)[0])+ «, » \ + str(SYZ.ElementNodalValues(Element.Id, FirstNodeId)[0])+ «, » \ + str(SXZ.ElementNodalValues(Element.Id, FirstNodeId)[0]) DesignAssessment.Helper.AppendToSolverOutputFile(Text)

This generates Mechanical APDL commands as follows: INISTATE, INISTATE, INISTATE, INISTATE, INISTATE, INISTATE,

SET, DTYP, DEFINE, 1, SET, DTYP, DEFINE, 2, SET, DTYP, DEFINE, 3,

STRESS all,all,all,77669520.0,-108961984.0,8667132.0,-127329504.0,40947276.0,-21408484.0 STRESS all,all,all,73086624.0,-54661364.0, 2108868.5,-50930028.0,-2542906.5,-13913089.0 STRESS all,all,all, 57340700.0, -85816616.0, -16383176.0, -96323688.0, 0.0, 0.0

For shells, the layers and integration points within layers have to also be considered. These are also defined as parameters of the INISTATE command. In the Design Assessment script, you must specify which integration point within the layer to obtain results for. This is done as follows: SX.ShellFaceResultDisplay = «Top» SY.ShellFaceResultDisplay = «Top» SZ.ShellFaceResultDisplay = «Top» SXY.ShellFaceResultDisplay = «Top» SYZ.ShellFaceResultDisplay = «Top» SXZ.ShellFaceResultDisplay = «Top» for Element in DesignAssessment.MeshData.Elements(): FirstNodeId = Element.Nodes()[0].Id Text = «INISTATE, SET, DTYP, STRESS\nINISTATE, DEFINE, » + str(Element.Id) + «, all,all,3, » \ + str(SX.ElementNodalValues(Element.Id, FirstNodeId)[0]) + «, » \ + str(SY.ElementNodalValues(Element.Id, FirstNodeId)[0]) + «, » \ + str(SZ.ElementNodalValues(Element.Id, FirstNodeId)[0]) + «, » \ + str(SXY.ElementNodalValues(Element.Id, FirstNodeId)[0])+ «, » \ + str(SYZ.ElementNodalValues(Element.Id, FirstNodeId)[0])+ «, » \ + str(SXZ.ElementNodalValues(Element.Id, FirstNodeId)[0]) DesignAssessment.Helper.AppendToSolverOutputFile(Text)

This obtains results from the explicit analysis on the top surface of the layer. When writing the Mechanical APDL commands, the layers are counted from the bottom, so here we specify layer 3 as we are defining the values for the top layer. The same thing is done for plastic strain and accumulated equivalent plastic strain. The full Solve script for Solids is included as a reference below:

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Using Design Assessment def RunDA(): UpstreamSolution = DesignAssessment.SolutionSelections()[0].SolutionByRow(1) UpstreamResult1 = UpstreamSolution.CreateSolutionResult(«»,»UVECTORS»,»Distance») #enter pre-processor Text = «/prep7\n» #write «Text» to solver output file» DesignAssessment.Helper.AppendToSolverOutputFile(Text) for Node in DesignAssessment.MeshData.Nodes(): NodeID = Node.Id #set variables to components of deformation vector result U1 = UpstreamResult1.NodalValues(NodeID)[0] U2 = UpstreamResult1.NodalValues(NodeID)[1] U3 = UpstreamResult1.NodalValues(NodeID)[2] print str(NodeID) + «: » +str(U3) #write commands to redefine node locations Text = «*GET, X_CO, NODE, » + str(NodeID) +», LOC, X,\n\ *GET, Y_CO, NODE, » + str(NodeID) + «, LOC, Y,\n\ *GET, Z_CO, NODE, » + str(NodeID) + «, LOC, Z,\n\ N, «+str(NodeID) + «, X_CO + («+ str(U1) +»), Y_CO + (» + str(U2) + «), Z_CO + (» + str(U3)+»)\n» DesignAssessment.Helper.AppendToSolverOutputFile(Text) #stress components SX = UpstreamSolution.CreateSolutionResult(«»,»SX»,»No Units») SY = UpstreamSolution.CreateSolutionResult(«»,»SY»,»No Units») SZ = UpstreamSolution.CreateSolutionResult(«»,»SZ»,»No Units») SXY = UpstreamSolution.CreateSolutionResult(«»,»SXY»,»No Units») SYZ = UpstreamSolution.CreateSolutionResult(«»,»SYZ»,»No Units») SXZ = UpstreamSolution.CreateSolutionResult(«»,»SXZ»,»No Units») #specify unaveraged integration method SX.IntegrationMethod = («unaveraged») SY.IntegrationMethod = («unaveraged») SZ.IntegrationMethod = («unaveraged») SXY.IntegrationMethod = («unaveraged») SYZ.IntegrationMethod = («unaveraged») SXZ.IntegrationMethod = («unaveraged»)

#plastic strain components EPPLX = UpstreamSolution.CreateSolutionResult(«»,»EPPLX»,»No Units») EPPLY = UpstreamSolution.CreateSolutionResult(«»,»EPPLY»,»No Units») EPPLZ = UpstreamSolution.CreateSolutionResult(«»,»EPPLZ»,»No Units») EPPLXY = UpstreamSolution.CreateSolutionResult(«»,»EPPLXY»,»No Units») EPPLYZ = UpstreamSolution.CreateSolutionResult(«»,»EPPLYZ»,»No Units») EPPLXZ = UpstreamSolution.CreateSolutionResult(«»,»EPPLXZ»,»No Units») EPPLX.IntegrationMethod = («unaveraged») EPPLY.IntegrationMethod = («unaveraged») EPPLZ.IntegrationMethod = («unaveraged») EPPLXY.IntegrationMethod = («unaveraged») EPPLYZ.IntegrationMethod = («unaveraged») EPPLXZ.IntegrationMethod = («unaveraged») #accumulated equivalent plastic strain EFF_PL_STNALL = UpstreamSolution.CreateSolutionResult(«»,»EFF_PL_STNALL»,»No Units») EFF_PL_STNALL.IntegrationMethod = («unaveraged»)

#specify reduced integration formulation for SOLID185 Text = » \n\n\net,1,185,,1\n/solu» DesignAssessment.Helper.AppendToSolverOutputFile(Text) for Element in DesignAssessment.MeshData.Elements(): #get ID of first node in element

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Examples of Design Assessment Usage FirstNodeId = Element.Nodes()[0].Id #write commands to initialise stress Text = «INISTATE, SET, DTYP, STRESS\nINISTATE, DEFINE, » + str(Element.Id) + «, all,all,all, » \ + str(SX.ElementNodalValues(Element.Id, FirstNodeId)[0]) + «, » \ + str(SY.ElementNodalValues(Element.Id, FirstNodeId)[0]) + «, » \ + str(SZ.ElementNodalValues(Element.Id, FirstNodeId)[0]) + «, » \ + str(SXY.ElementNodalValues(Element.Id, FirstNodeId)[0])+ «, » \ + str(SYZ.ElementNodalValues(Element.Id, FirstNodeId)[0])+ «, » \ + str(SXZ.ElementNodalValues(Element.Id, FirstNodeId)[0]) DesignAssessment.Helper.AppendToSolverOutputFile(Text) for Element in DesignAssessment.MeshData.Elements(): FirstNodeId = Element.Nodes()[0].Id #write commands to initalise plastic strain Text2 = «INISTATE, SET, DTYP, EPPL\nINISTATE, DEFINE, «+ str(Element.Id) + str(EPPLX.ElementNodalValues(Element.Id, FirstNodeId)[0]) + «, + str(EPPLY.ElementNodalValues(Element.Id, FirstNodeId)[0]) + «, + str(EPPLZ.ElementNodalValues(Element.Id, FirstNodeId)[0]) + «, + str(EPPLXY.ElementNodalValues(Element.Id, FirstNodeId)[0])+ «, + str(EPPLYZ.ElementNodalValues(Element.Id, FirstNodeId)[0])+ «, + str(EPPLXZ.ElementNodalValues(Element.Id, FirstNodeId)[0]) DesignAssessment.Helper.AppendToSolverOutputFile(Text2)

+ » » » » «

«, all,all,all, «\ \ \ \ \ \

for Element in DesignAssessment.MeshData.Elements(): FirstNodeId = Element.Nodes()[0].Id #write commands to initalise accumulated equivalent plastic strain Text2 = «INISTATE, SET, DTYP, PLEQ\nINISTATE, DEFINE, «+ str(Element.Id) + «, all,all,all, «\ + str(EFF_PL_STNALL.ElementNodalValues(Element.Id, FirstNodeId)[0]) DesignAssessment.Helper.AppendToSolverOutputFile(Text2) Text = «solve» RunDA()

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Productivity Tools The Mechanical application includes several features designed to help you create, navigate, and manage data in complex databases where a large number of objects are present. These features include tags, tree filtering, and the object generator. This section examines the following topics: • Generating Multiple Objects from a Template Object (p. 1287) • Tagging Objects (p. 1292) • Filtering the Tree (p. 9)

Generating Multiple Objects from a Template Object You can use the Object Generator to make one or more copies of a template object, scoping each to a different piece of geometry. Almost any tree object that supports the “Duplicate” function can be used as a template. To use the Object Generator, you define a tree object to be copied, select the geometry to which it should be copied, and generate from the Object Generator. The original tree object is copied to all of the selected geometry, with all details from the original object maintained. You have the option of adding a common prefix and/or tag to the name of all generated objects. • If your object must be scoped to more than one geometry set, you have a choice for how that scoping is handled. • For objects with locations, such as remote points, you can choose to move the location to the centroid of the new geometry, or leave the location unchanged. • If the geometry from the template object is part of the target geometry selection set, you can choose to ignore or include it. • For any connections requiring two sets of geometry, you specify one named selection for each side of the connection. The Object Generator will then generate a connection between any geometry on each side which falls within a specified distance. • Since end releases require a vertex and an edge, you can specify named selections for the vertices and edges. The Object Generator will then generate an end release for every specified vertex with an edge in the specified set of edges. Example 6: Generating Clamping Bolts For example, you have two retaining collars with one clamping bolt defined.

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You can use the object generator to generate the other bolt connections.

Generating an Object To use the Object Generator: 1.

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Generating Multiple Objects from a Template Object 2.

In the Tree Outline, select the tree object to be copied. Define any details you want included in the generated objects.

3.

In the Geometry window, select the geometry to which the tree object should be copied in the Object Generator window.

4.

In the Object Generator window, select any required options. The options vary, depending on the selected object. Possible options are: Option Name

Shown for Object Type

Description

Scope to

• General objects supporting one geometry selection

When multiple geometry items are selected, you have several options for scoping the new object.

• Connection objects

• Each Entity: Scope one new object to each geometric entity selected. • Adjacent Entities: Scope one object to all groups of adjacent selected entities. This is the default. • All Entities by Part: Scope one new object to all selected geometric entities on each part.

Note If none of the selected topologies are adjacent, then both options will work in a similar manner. Ignore Original

All

If the geometry for the original object is part of the target selection set, this option directs the Object Generator to ignore the original and scope new objects only onto geometry not scoped to the original object. This option is selected by default. If you clear this option, the Object Generator copies new objects to all specified geometry, including that of the original, if selected. Note that this may result in duplicate objects.

Name Prefix

All

If you want all generated objects to have a common name prefix, enter the desired prefix in the Name Prefix field.

Apply Tag

All

If you want to apply a label to all generated objects, enter a tag name in the Apply Tag

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Productivity Tools Option Name

Shown for Object Type

Description field. Tags can be used to filter your tree. For more information on tags, see Tagging Objects (p. 1292).

Relocate

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When relocation is possible, applies to:

For objects with locations, such as remote points, you have an option for how to handle the location of the generated objects.

• General objects supporting one geometry selection

• Yes: For generated objects, the remote point will be the centroid of the new geometry. This is the default.

• Connection objects

• No: Leave the location of the remote point as is when generating the new objects.

Generate from

If named selections are defined, applies to general objects supporting one geometry selection

Select whether to use the geometric entities selected in the Geometry window (Current Selection) or a named selection.

Reference

Springs

Select the named selection to use as the Reference side of the connection. You specify the other side using the Mobile option, then specify the lower and upper boundaries of the distance between sides to generate connections.

Mobile

Springs

Select the named selection to use as the Mobile side of the connection. You specify the other side using the Reference option, then specify the lower and upper boundaries of the distance between sides to generate connections.

Master

Mesh connections

Select the named selection to use as the Master side of the connection. You specify the other side using the Slave option, then specify the lower and upper boundaries of the distance between sides to generate connections.

Slave

Mesh connections

Select the named selection to use as the Slave side of the connection. You specify the other side using the Master option, then specify the lower and upper boundaries of the distance between sides to generate connections.

Contact

Contacts

Select the named selection to use as the contact side of the connection. You specify the other side using the Target option, then specify the lower and upper boundaries of the distance between sides to generate connections.

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Generating Multiple Objects from a Template Object Option Name

Shown for Object Type

Description

Target

Contacts

Select the named selection to use as the target side of the connection. You specify the other side using the Contact option, then specify the lower and upper boundaries of the distance between sides to generate connections.

Minimum

Connection objects

For connections, specify the lower boundary. The Object Generator will generate a connection between any geometry on each side which falls within the specified distance. The distance is defined as the distance between the centroid of one geometric selection and the centroid of the another geometric selection.

Maximum

Connection objects

For connections, specify the upper boundary. The Object Generator will generate a connection between any geometry on each side which falls within the specified distance. The distance is defined as the distance between the centroid of one geometric selection and the centroid of the another geometric selection.

Edges

End releases

For end releases, select a named selection that encompasses edges for which you want to generate objects. The Object Generator will generate an end release for every specified vertex specified in Vertices if it has an edge in the specified set of edges.

Vertices

End releases

For end releases, select a named selection that encompasses vertices for which you want to generate objects. The Object Generator will generate an end release for every specified vertex if it has an edge in the specified set of edges specified in Edges.

Source

Mesh method control

Select the named selection to use as the Source. Source appears in the Object Generator window for the Sweep and MultiZone mesh methods only. Specifying a Source is optional. You specify the target using the Target option.

Target

Mesh method control

Select the named selection to use as the Target. Target appears in the Object Generator window for the Sweep mesh method only. Specifying a Target is optional. You specify the source using the Source option.

High

Mesh match control

Select the named selection to use as the high side of the match control. You specify the other side using the Low option. The Object Generator will not assign a coordinate system. You must assign a coordinate system manually.

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5.

Option Name

Shown for Object Type

Description

Low

Mesh match control

Select the named selection to use as the low side of the match control. You specify the other side using the High option. The Object Generator will not assign a coordinate system. You must assign a coordinate system manually.

Boundary

Mesh inflation control

Select the named selection to use as the inflation boundary.

Click Generate to copy the selected tree object to the selected geometry.

Tagging Objects For complex models, it may be difficult to keep track of all of the objects in your tree. With tags, you can mark objects in the tree with meaningful labels, which can then be used to filter the tree. For more information on filtering, see Filtering the Tree (p. 9). Tags are managed through the Tags window. To view this window, click the Tags button in the Graphics toolbar. This section covers the following: Creating Tags Applying Tags to Objects Deleting a Tag Renaming a Tag Highlighting Tagged Tree Objects

Creating Tags To create a tag and apply it to the currently-selected tree object: 1.

In the Tree Outline, select an object.

2.

In the Tags window, click the Add a Tag icon. The Add New Tag window appears.

3.

Enter a name for the tag and click OK. The tag is listed in the Tags window. The check box is selected to indicate that it applies to the selected object in the tree.

Applying Tags to Objects Once you have created tags, you can apply those tags to other objects in the tree. To apply a tag to a tree object: 1.

In the Tree Outline, select an object.

2.

In the Tags window, select the check box for all tags you want to add to that object.

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Tagging Objects You can now use these tags to filter the tree. For more information on filtering the tree, see Filtering the Tree (p. 9).

Deleting a Tag To remove a tag: 1.

In the Tags window, select one or more tags.

2.

Click the Delete Tag(s) icon, or right-click the Tags window and select Delete Tag(s) .

Renaming a Tag To rename a tag: 1.

In the Tags window, select a tag.

2.

Click the Rename Tag icon. The Rename Tag window appears.

3.

Enter a name for the tag and click OK. The new tag name is listed in the Tags window.

Highlighting Tagged Tree Objects Once a tag is applied to objects in the Tree Outline, you can highlight all of the objects with a selected tag. You can search for objects that apply to one or more tags. When you select multiple tags, you have several options. You can search for objects that contain any of the selected tags, or you can search for objects that contain all of the selected tags. To highlight objects: 1.

In the Tags window, select one or more tags

2.

Right-click the Tags window and select one of the following options: • Find items with selected tag: Available when only one tag is selected, this option highlights all tree objects with the selected tag. • Find items with all selected tags: Available when multiple tags are selected, this option highlights all items that contain every one of the selected tags. • Find items with any selected tags: Available when multiple tags are selected, this option highlights all items that contain one of the selected tags. Tree objects matching the selected number of tags are highlighted.

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Mechanical Objects Reference Welcome to the Mechanical Objects Reference. This reference provides a specification for every Mechanical object in the tree. Each object is represented in either its own reference page, or is combined with similar objects and represented on one group reference page. For example, the Joint object is represented on its own Joint object reference page, whereas the Acceleration object is represented on the Loads and Supports (Group) object reference page. All pages representing groups of objects include «(Group)” as part of the page’s title.

Note Certain types of objects do not appear in the tree but are still represented on their own pages in this reference. These include Virtual Cell objects, Virtual Hard Vertex objects, Virtual Split Edge objects, and Virtual Split Face objects. When these types of objects are created, they are saved in the database and have editable properties similar to other objects. For details, refer to the individual reference pages for these objects. A complete alphabetical listing of Mechanical objects reference pages is included below. To determine the reference page for an object in a group, consult the group page whose title matches the object, and check the entry: “Applies to the following objects”. The following is a description of each component of a Mechanical object reference page: • Title — For individual object reference pages, the title is the default name of the object as it appears in the tree. For group reference pages, the title is a name given to the collection of objects represented. • Object definition — A brief description of the individual object or group of objects. • Applies to the following objects — Appears only on group reference pages and includes the default name of all objects represented on the group reference page. • Tree dependencies — The valid location of the object or group of objects in the tree (Valid Parent Tree Object), as well as other possible objects that you can insert beneath the object or group of objects (Valid Child Tree Objects). • Insertion options — Procedure for inserting the object (individual or one in the group) in the tree. Typically this procedure includes inserting the object from a context toolbar button or through a context menu option when you click the right mouse button with the cursor on the object. • Additional related information — a listing of topics related to the object or object group that are in the help. Included are links to those topics. • Tree location graphic — an indication of where the object or group of objects appears in the tree. • Object Properties — a listing of every setting or indication available in the Details view (located directly beneath the object tree) for the object. Included are links to more detailed information on an item within the help.

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Objects Reference • Relevant right mouse button context menu options — a listing of options directly relevant to the objects that are available in the context menu through a right mouse click on the object. Included are links to more detailed information on an item within the help. The options listed are in addition to options that are common to most of the objects (such as Solve, Copy, Cut, Duplicate, and Delete). The objects reference is not intended to be your primary source of procedural information for performing simulations — see the «Steps for Using the Mechanical Application» section for introductory and procedural guidelines concerning when and where to use Mechanical objects.

Page Listings The following is an alphabetical listing of object reference pages: Alert Analysis Settings Angular Velocity Beam Body Body Interactions Body Interaction Chart Commands Comment Connections Connection Group Construction Geometry Contact Debonding Contact Region Contact Tool (Group) Convergence Coordinate System Coordinate Systems Crack Direct FE (Group) End Release Environment (Group) Fatigue Tool (Group) Figure Fluid Surface Fracture Gasket Mesh Control Geometry Global Coordinate System Image Imported Layered Section Imported Load (Group) Imported Remote Loads Imported Thickness Imported Thickness (Group) Initial Conditions Initial Temperature Interface Delamination Joint Layered Section 1296

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Alert Loads, Supports, and Conditions (Group) Mesh Mesh Connection Mesh Control Tools (Group) Mesh Group (Group) Mesh Grouping Mesh Numbering Modal Model Named Selections Numbering Control Part Path Periodic/Cyclic Region Point Mass Pre-Meshed Crack Pre-Stress Probe Project Remote Point Remote Points Result Tracker Results and Result Tools (Group) Solution Solution Combination Solution Information Spot Weld Spring Stress Tool (Group) Surface Symmetry Symmetry Region Thermal Point Mass Thickness Validation Velocity Virtual Body Virtual Body Group Virtual Cell Virtual Hard Vertex Virtual Split Edge Virtual Split Face Virtual Topology

Alert Sets pass or fail thresholds for individual results. When a threshold is exceeded, the status symbol changes in front of the associated result object. The status is also displayed in the Details view of the Alert object. Alerts facilitate the presentation of comparisons in automatic reports.

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Objects Reference Tree Dependencies: • Valid Parent Tree Objects: All result objects (independent, or under result tools), except Damage Matrix, Fatigue Sensitivity, Hysteresis, Phase Response, Probe, Rainflow Matrix, Reactions, Status, Vector Principal Elastic Strain, Vector Principal Stress. • Valid Child Tree Objects: Comment Insertion Options: Click right mouse button on a result object or in the Geometry window after you select the result object, and then> Insert> Alert.

Object Properties The Details view properties for this object include the following. Category

Fields

Definition

Fails If — Set failure threshold as Minimum Below Value or Maximum Above Value, where you set the value in the next field. Value — Threshold value in the units of the associated result.

Results

Status — Read-only indication of the pass/fail status; also includes criterion (for example: “Passed: Minimum Above Value”).

Analysis Settings Allows you to define various solution settings that are customized to specific analysis types. Tree Dependencies: • Valid Parent Tree Object: Any environment object. • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: Appears by default when you create an analysis system. Additional Related Information: • Establish Analysis Settings (p. 134) • «Configuring Analysis Settings» (p. 635)

Object Properties For more information on this object’s properties, see the Analysis Settings for Most Analysis Types (p. 635) section.

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Angular Velocity

Angular Velocity Applies angular velocity as an initial condition for use in an explicit dynamics analysis.

Note • For explicit dynamics analyses, the center of rotation for an angular velocity is defined by the origin of the coordinate system associated with the angular velocity. • Angular Velocity initial conditions are not supported for 2D axisymmetric Explicit Dynamics analyses.

Tree Dependencies: • Valid Parent Tree Object: Initial Conditions • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: Use any of the following methods after highlighting Initial Conditions object: • Click Angular Velocity button on Initial Conditions context toolbar. • Click right mouse button on Initial Conditions object or in the Geometry window>Insert>Angular Velocity. Additional Related Information: • Define Initial Conditions • Explicit Dynamics Analysis

Object Properties The Details view properties for this object include the following. Category

Fields

Scope

Scoping Method Geometry– appears if Scoping Method is set to Geometry Selection. In this case, use selection filters to pick geometry, click in the Geometry field, then click Apply. Named Selection – appears if Scoping Method is set to Named Selection.

Definition

Input Type — choose either Angular Velocity or Velocity. Define By Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Objects Reference Category

Fields Total — magnitude; appears if Define By is set to Vector. Direction- appears if Define By is set to Vector. Coordinate System – available list; appears if Define By is set to Components. X, Y, Z Component – values; appears if Define By is set to Components. Suppressed

Beam A beam is a structural element that carries load primarily in bending. Tree Dependencies: • Valid Parent Tree Object: Connections • Valid Child Tree Objects: Commands, Comment, Figure, Image Insertion Options: Use any of the following methods after highlighting Connections object: • Click Body-Ground> Beam or Body-Body> Beam, as applicable on Connections context toolbar. • Click right mouse button on Connections object or in the Geometry window> Insert> Beam. Additional Related Information: • Connections Context Toolbar • Beam Connections (p. 614) The following right mouse button context menu options are available for this object. • Enable/Disable Transparency — similar behavior to feature in Contact Region. • Rename Based on Definition — similar behavior to feature in Results. • Promote Remote Point (when the Applied By property is set to Remote Attachment).

Object Properties The Details view properties for this object include the following. Category

Fields

Graphics Properties

Visible – toggles visibility of the beam.

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Beam Definition

Material — defined in Engineering Data. Cross Section — read-only indication. Radius Suppressed

Scope — inform- Scope — includes the options Body-Body or Body-Ground. ation on springs also applies to beams. Reference — information on springs also applies to beams.

The following properties are available when the Scope property is set to BodyBody: Scoping Method — specify as Geometry Selection, Named Selection, or Remote Point. Applied By — specify as Remote Attachment (default) or Direct Attachment. The default for this property can differ if you first select geometry or a mesh node. Scope — displays when the Scoping Method property is set to Geometry Selection. Once a geometry is selected, click in the Scope field and then click Apply. Reference Component — displays when the Scoping Method property is set to Named Selection. This property provides a drop-down list of available user–defined Named Selections. Remote Points — displays when the Scoping Method property is set to Remote Point. This property provides a drop-down list of available user–defined Remote Points. Body — a read-only indication of scoped geometry. Displays for BodyBody scoping. The following properties display for either Body-Body or Body-Ground scoping when the Applied By property is set to Remote Attachment. Coordinate System Reference X Coordinate Reference Y Coordinate Reference Z Coordinate Reference Location Behavior — specify the scoped geometry as either Rigid or Deformable. Pinball Region

Mobile — information on springs also applies to beams.

The following properties are available when the Scope property is set to BodyBody: Scoping Method — specify as Geometry Selection, Named Selection, or Remote Point. Applied By — specify as Remote Attachment (default) or Direct Attachment. The default for this property can differ if you first select geometry or a mesh node. Scope — displays when the Scoping Method property is set to Geometry Selection. Once a geometry is selected, click in the Scope field and then click Apply. Reference Component — displays when the Scoping Method property is set to Named Selection. This property provides a drop-down list of available user–defined Named Selections.

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Objects Reference Remote Points — displays when the Scoping Method property is set to Remote Point. This property provides a drop-down list of available user–defined Remote Points. Body — a read-only indication of scoped geometry. Displays for BodyBody scoping. Behavior — specify the scoped geometry as either Rigid or Deformable. Pinball Region The following properties display for either Body-Body or Body-Ground scoping when the Applied By property is set to Remote Attachment. Coordinate System Mobile X Coordinate Mobile Y Coordinate Mobile Z Coordinate Mobile Location

Body Defines a component of the attached geometry included under a Geometry object, or under a Part object if considered a multibody part (shown in the figure below). Also see the description of the Virtual Body (p. 1405) object (applicable to assembly meshing algorithms only). Tree Dependencies: • Valid Parent Tree Object: Geometry or Part (if under a multibody part) • Valid Child Tree Objects: Commands, Comment, Figure, Gasket Mesh Control, Image Insertion Options: Appears by default when geometry is attached. Additional Related Information: • Define Part Behavior (p. 129) • «Specifying Geometry in the Mechanical Application» (p. 371) The following right mouse button context menu options are available for this object. • Search Faces with Multiple Thicknesses • Create Selection Group • Generate Mesh • Preview> Surface Mesh — appears only for a solid body.

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Body • Preview> Inflation

Object Properties The Details view properties for this object include the following. Category

Fields

Graphics Properties

Visible — turns part display On or Off in the Geometry window Transparency — varies the body between being completely transparent (0) to completely opaque (1) Color — sets the color of the body.

Definition

Suppressed Stiffness Behavior — appears only for a single solid body that is not a component of a multibody part Brick Integration Scheme — appears only if Element Control is set to Manual in the Details view of the Geometry object; not available if Stiffness Behavior is set to Rigid Coordinate System — assign a local coordinate system to specify the alignment of the elements of the body if previously defined using one or more Coordinate System objects; not available if Stiffness Behavior is set to Rigid Reference Temperature Reference Temperature Value — available only when you select By Body as the Reference Temperature Reference Frame — appears only for solid bodies when an Explicit Dynamics system is part of the solution Thickness — appears only for a surface body Thickness Mode — appears only for a surface body; read-only indication Offset Mode — appears only for a line body Offset Type — appears only for a line body Model Type — appears only for a line body

Material

Assignment Nonlinear Effects — not available if Stiffness Behavior is set to Rigid. Thermal Strain Effects Fluid/Solid — available only in the Meshing application (i.e., not available if you are using the meshing capabilities from within the Mechanical application). Useful in assembly meshing. Allows you to control the physics that occur on a model. Valid options are Fluid, Solid, and Defined By Geometry. When set to Defined By Geometry, the value is based on the Fluid/Solid material property that was assigned to the body in the DesignModeler application.

Bounding Box

Length X Length Y Length Z

Properties Indications of the prop-

Volume Mass

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Objects Reference erties originally assigned to the body.

Length — appears only for line bodies

Note If the material density is temperature dependent, the Mass will be computed at the body temperature, or at 22oC (default temperature for an environment). The following appear for all bodies except line bodies: Centroid X Centroid Y Centroid Z Moment of Inertia Ip1 Moment of Inertia Ip2 Moment of Inertia Ip3 Surface Area (approx.) — appears only for a surface body The following appear for line bodies only: Cross Section Cross Section Area Cross Section IYY Cross Section IZZ The following appear for surface bodies only: Offset Type Membrane Offset — appears for surface bodies when Offset Type = User Defined

Statistics: Read-only indication of the entities that comprise the body.

Nodes Elements Mesh Metric

Body Interactions Sets global options for all Body Interaction objects in an Explicit Dynamics Analysis.

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Body Interactions Tree Dependencies: • Valid Parent Tree Object: Connections • Valid Child Tree Objects: Body Interaction, Comment, Figure, Image Insertion Options: Automatically inserted in the tree if contact is detected when model is attached. Also, use any of the following methods after highlighting Connections object: • Click Body Interaction button on Connections context toolbar. • Click right mouse button on Connections object or in the Geometry window>Insert>Body Interaction. Additional Related Information: • Body Interaction (p. 1306) • Body Interactions in Explicit Dynamics Analyses (p. 619) • Explicit Dynamics Analysis (p. 155)

Object Properties The Details view properties for this object include the following. Category

Fields

Advanced

Contact Detection Formulation — appears if Contact Detection = Trajectory. Shell Thickness Factor — appears if the geometry includes one or more surface bodies and if Contact Detection = Trajectory. Pinball Factor — appears if Contact Detection = Proximity Based. Timestep Safety Factor — appears if Contact Detection = Proximity Based. Limiting Timestep Velocity — appears if Contact Detection = Proximity Based. Edge on Edge Contact — appears if Contact Detection = Proximity Based. Body Self Contact Element Self Contact Tolerance — appears if Contact Detection = Trajectory and Element Self Contact = Yes.

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Objects Reference

Body Interaction Creates contact between bodies in an Explicit Dynamics Analysis. Tree Dependencies: • Valid Parent Tree Object: Body Interactions • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: • Automatically inserted in the tree if model includes a Body Interactions object. • For manual insertion, use any of the following methods after highlighting Connections object. – Choose Body Interaction on Connections context toolbar. – Click right mouse button on Connections object, or in the Geometry window>Insert>Body Interaction. Additional Related Information: • Body Interactions (object reference) • Body Interactions • Explicit Dynamics Analysis

Object Properties The Details view properties for this object include the following. Category

Fields

Scope

Scoping Method Geometry – appears if Scoping Method is set to Geometry Selection. In this case, use selection filters to pick geometry, click in the Geometry field, then click Apply. Named Selection – appears if Scoping Method = Named Selection.

Definition

Type Maximum Offset – appears if Type = Bonded. Breakable – appears if Type = Bonded. Normal Stress Limit – appears if Type = Bonded and Breakable = Stress Criteria.

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Commands Category

Fields Normal Stress Exponent – appears if Type = Bonded and Breakable = Stress Criteria. Shear Stress Limit – appears if Type = Bonded and Breakable = Stress Criteria. Shear Stress Exponent – appears if Type = Bonded and Breakable = Stress Criteria. Friction Coefficient – appears if Type = Frictional. Dynamic Coefficient – appears if Type = Frictional. Decay Constant – appears if Type = Frictional. Suppressed

Chart Represents a chart that you can create for loads and/or results against time, or result quantities against a load or another result quantity. Tree Dependencies: • Valid Parent Tree Object: Model • Valid Child Tree Objects: Comment, Image Insertion Method: Click the Chart and Table button on the standard toolbar. Additional Related Information: • Chart and Table (p. 988) • Standard Toolbar

Object Properties For more information on this object’s properties, see the Chart and Table (p. 988) section.

Commands • Allows use of Mechanical APDL application commands or APDL programming in a simulation. • Allows use of Python for the Transient Structural (Rigid Dynamics) system.

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Objects Reference Tree Dependencies: • Valid Parent Tree Objects: Body, Contact Region (shown in figure), environment objects, Joint, Pre-Stress, Solution, Spring • Valid Child Tree Objects: Comment, Image Insertion Options: Choose one of the following: • Click right mouse button on either the parent object (see above) or in the Geometry window> Insert> Commands. • Highlight the parent object (see above) and choose the Insert Commands button from the toolbar. Additional Related Information: • Commands Objects Tree Dependencies for the Transient Structural (Rigid dynamics) system: • Valid Parent Tree Objects: Connections Folder, Joint, Spring, Environment, Joint Condition. The following right mouse button context menu options are available for this object. • Export… • Import… • Refresh • Suppress • Search Parameters — appears only if Commands object is under a Solution object. • Rename Based on Definition

Object Properties The Details view properties for this object include the following. Category

Fields/Descriptions

File

File Name — Read-only indication of imported text file name (including path) if used. File Status — Read-only indication of the status of an imported text file if used.

Definition

Suppressed Target — displays a list of solvers. Invalidate Solution — applicable for the Solution object only. Output Search Prefix — applicable for the Solution object only. Step Selection Mode — applicable only for stepped analyses, and only when inserting under an environment object.

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Connections Step Number — applicable only for stepped analyses, and only when inserting under an environment object. ARG1 through ARG9

Input Arguments Results

Applicable only when inserting under a Solution object.

Comment Inserts a comment for a Mechanical parent object. The comment editor creates a fragment of HTML, and the object itself consists of that HTML fragment, a string denoting the author’s name, and a color. Report adds the resulting HTML fragment directly in line, in the specified color and notes the author. The Comment context toolbar provides buttons to insert an image or to apply various text formatting tags. Tree Dependencies: • Valid Parent Tree Objects: All objects. • Valid Child Tree Objects: None. Insertion Method: Click the Comment button on the standard toolbar. Additional Related Information: • Inserting Comments, Images, and Figures (p. 121) • Comment Context Toolbar • Reporting

Object Properties The Details view properties for this object include the following. Category

Fields/Descriptions

Author

Name

Connections Defines connections between two or more parts or bodies. Includes global settings in Details view that apply to all Contact Region, Spot Weld, Mesh Connection, Body Interaction (for explicit dynamics analyses), Joint, Spring, and Beam child objects.

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Objects Reference Tree Dependencies: • Valid Parent Tree Object: Model • Valid Child Tree Objects: Beam, Body Interactions, Comment, Connection Group (including those named Contacts, Joints, and Mesh Connections; Contact Tool, Figure, Image, Joint, Solution Information, Spot Weld, Spring, Insertion Options: • Automatically inserted in the tree if connection is detected when model is attached. • For setting connections manually, use any of the following methods after highlighting Model object: – Click Connections button on Model context toolbar. – Click right mouse button on Model object or in the Geometry window> Insert> Connections.

Note These options are not available if a Connections object already exists in the tree.

Additional Related Information: • Beams • Body Interactions • Connections Overview • Automatically Generated Connections • Contact Region Settings • Mesh Connection • Contact Ease of Use Features • Contact Tool and Results • Contact Options Preferences • Joints

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Connection Group • Spot Welds • Springs The following right mouse button context menu options are available for this object. • Create Automatic Connections — available only if at least one Connection Group folder is present. • Redundancy Analysis — available if at least one Joint object is present. • Enable/Disable Transparency • Search Connections for Duplicate Pairs • Rename Based on Definition

Object Properties The Details view properties for this object include the following. Category Auto Detection Transparency

Fields Generate Automatic Connection On Refresh Enabled

Connection Group Defines connections among selected bodies. Includes global settings in Details view that apply to all Contact Region, Mesh Connection, or Joint child objects. Tree Dependencies: • Valid Parent Tree Object: Connections • Valid Child Tree Objects: Comment, Contact Region, Figure, Image, Joint, Mesh Connection Insertion Options: Use any of the following methods after highlighting Connections object: • Click Connection Group on Connections context toolbar. • Click right mouse button on Connections object (or on another Connection Group object), or in the Geometry window; then Insert> Connection Group. • Insert a Contact Region, Mesh Connection, or Joint object. A separate parent Connection Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Objects Reference Group object is created automatically for each of these three types of objects, and is renamed Contacts, Mesh Connections, or Joints accordingly. Additional Related Information: • Automatically Generated Connections • Contact Region Settings • Mesh Connection • Joints (p. 542) The following right mouse button context menu options are available for this object. • Create Automatic Connections • Enable/Disable Transparency • Search Connections for Duplicate Pairs • Rename Based on Definition

Object Properties The Details view properties for this object include the following. Category

Fields

Definition

Connection Type

Scope

Scoping Method Geometry– appears if Scoping Method is set to Geometry Selection. In this case, use selection filters to pick geometry, click in the Geometry field, then click Apply. Named Selection – appears if Scoping Method is set to Named Selection.

Auto Detection

Tolerance Type (p. 498) Tolerance Slider (p. 498) Tolerance Value (p. 498) Use Range (p. 498) Min Distance Percentage (p. 498) Min Distance Value (p. 498) Face/Face Face/Edge — appears only for contacts and mesh connection groups. Edge/Edge — appears only for contacts and mesh connection groups. Priority — appears only for contacts and mesh connection groups. Group By Search Across Revolute Joints — appears only for joint groups. Fixed Joints — appears only for joint groups.

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Contact Debonding

Construction Geometry Houses one or more Path and/or Surface objects. You can apply results to paths and surfaces that you define. Tree Dependencies: • Valid Parent Tree Object: Model • Valid Child Tree Objects: Comment, Figure, Image, Path, Surface. Insertion Options: Use any of the following methods after highlighting Model object: • Click Construction Geometry button on Model context toolbar • Click right mouse button on Model object or in the Geometry window >Insert>Construction Geometry.

Note The Model folder can contain only one Construction Geometry object. Additional Related Information: • Path (Construction Geometry) (p. 453) • Surface (Construction Geometry) (p. 459) • Path (p. 1372) object reference • Surface (p. 1397) object reference

Contact Debonding The Contact Debonding object defines contact regions along a contact interface that will separate. Tree Dependencies: • Valid Parent Tree Object: Fracture Insertion Options: Use any of the following methods after highlighting Fracture object: • Click the Contact Debonding button on the Fracture context toolbar. • Click right mouse button on the Fracture object, Interface Delamination object, or Contact Debonding object and select Insert>Contact Debonding.

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Objects Reference Additional Related Information: • Interface Delamination and Contact Debonding • Fracture Analysis The following right mouse button context menu options are available for this object. • Insert>Interface Delamination • Insert>Contact Debonding • Suppress

Object Properties The Details view properties for this object include the following. Category

Fields

Definition

Type — Read-only field that describes the object — Contact Debonding. Method — Read-only field that describes the formulation used to introduce the fracture mechanism — Cohesive Zone Material (CZM) model. Material — Fly-out menu for Material selection or specification. Materials are specified in Engineering Data. Suppressed — Includes or excludes the object in the analysis.

Scope

Contact Region — Specify the Contact Region of the contact interface that is associated with the Contact Debonding object. The properties for the contact elements require that the contact Type be Bonded or No Separation contact and that the Formulation is specified as the Augmented Lagrange method or the Pure Penalty method.

Contact Region Defines conditions for individual contact and target pairs. Several Contact Regions can appear as child objects under a Connection Group object. The Connection Group object name automatically changes to Contacts. Tree Dependencies: • Valid Parent Tree Object: Connection Group • Valid Child Tree Objects: Commands, Comment, Figure, Image Insertion Options: Use any of the following methods after highlighting Connections or Connection Group object: • Inserted automatically if you choose Create Automatic Connections through a right mouse click on Connections (or Contacts) object. • Click Contact on Connections context toolbar and choose a contact type.

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Contact Region • Click right mouse button on Connections (or Connection Group) object or in the Geometry window; then Insert> Manual Contact Region. Additional Related Information: • Contact Region Settings • Automatically Generated Connections • Global Connection Settings — See the Connections Folder and Connection Group Folder sections. • Connections Context Toolbar • Setting Contact Conditions Manually • Contact Ease of Use Features • Contact Tool and Results • Contact Options Preferences • Interface Delamination using ANSYS Composite PrepPost (ACP) The following right mouse button context menu options are available for this object. • Enable/Disable Transparency • Hide All Other Bodies • Flip Contact/Target • Search Connections for Duplicate Pairs • Go To Connections for Duplicate Pairs — available if connection object shares the same geometries with other connection objects. • Save Contact Region Settings • Load Contact Region Settings • Reset to Default • Promote to Named Selection • Rename Based on Definition

Object Properties Choose the object properties below that apply to your analysis type. Object Properties — Most Structural Analyses Object Properties — Explicit Dynamics Analyses Object Properties — Thermal and Electromagnetic Analyses Object Properties — Rigid Body Dynamics Analyses

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Objects Reference

Object Properties — Most Structural Analyses The Details view properties for this object include the following. Category

Fields/Conditions

Scope

Scoping Method Interface — displays when the Scoping Method is set to Pre-Generated Interface. Contact Target Contact Bodies Target Bodies Contact Shell Face — appears for surface bodies. Target Shell Face — appears for surface bodies.

Definition

Type Friction Coefficient — if Type = Frictional Scope Mode Behavior Trim Contact Trim Tolerance — if Trim Contact is set to On. Suppressed

Advanced

Formulation Detection Method Penetration Tolerance Elastic Slip Tolerance Normal Stiffness Normal Stiffness Factor — if Normal Stiffness = Manual Constraint Type — if Formulation = MPC and scoping of Contact Bodies or Target Bodies is to a surface body. Update Stiffness — if Formulation = Augmented Lagrange or Pure Penalty Stabilization Damping Factor — Helps reduce the risk of rigid body motion. Available for Frictionless, Rough, and Frictional contact types. Thermal Conductance Pinball Region Pinball Radius — if Pinball Region = Radius Electric Conductance Electric Conductance Value — if Electric Conductance = Manual Time Step Controls — if Type = Frictionless, Rough, or Frictional Restitution Factor — Rigid Body Dynamics Solver Only

Geometric Modification

Interface Treatment Offset — if Interface Treatment = Add Offset Contact Geometry Correction. Supporting properties include: • Orientation • Mean Pitch Diameter • Pitch Distance • Thread Angle

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Contact Region Category

Fields/Conditions • Thread Type • Handedness

Basics of Contact Region object

Object Properties — Explicit Dynamics Analyses The Details view properties for this object include the following. Category

Fields/Conditions

Scope

Scoping Method Contact Target Contact Bodies Target Bodies

Definition

Type Friction Coefficient — if Type = Frictional Dynamic Coefficient — if Type = Frictional Decay Constant — if Type = Frictional Scope Mode Behavior Maximum Offset — if Type = Bonded Breakable — if Type = Bonded Normal Stress Limit — if Type = Bonded and Breakable = Stress Criteria Normal Stress Exponent — if Type = Bonded and Breakable = Stress Criteria Shear Stress Limit — if Type = Bonded and Breakable = Stress Criteria Shear Stress Exponent — if Type = Bonded and Breakable = Stress Criteria Suppressed

Basics of Contact Region object

Object Properties — Thermal and Electromagnetic Analyses The Details view properties for this object include the following. Category

Fields/Conditions

Scope

Scoping Method Contact (p. 507) Target (p. 508) Contact Bodies (p. 508) Target Bodies (p. 508) Contact Shell Face (p. 508) — appears for surface bodies. Target Shell Face (p. 508) — appears for surface bodies.

Definition

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Objects Reference Category

Fields/Conditions Scope Mode Behavior Suppressed

Advanced

Formulation Constraint Type — if Formulation = MPC and scoping of Contact Bodies or Target Bodies is to a surface body. Interface Treatment Offset — if Interface Treatment = Add Offset. Normal Stiffness (Magnetostatic analyses and all thermal analyses) if Formulation = Augmented Lagrange, Pure Penalty, or MPC. Normal Stiffness Factor (Magnetostatic analyses and all thermal analyses) — if Normal Stiffness = Manual Update Stiffness (Magnetostatic analyses and all thermal analyses) if Formulation = Augmented Lagrange, Pure Penalty, or MPC. Thermal Conductance (Magnetostatic analyses and all thermal analyses) Thermal Conductance Value (Magnetostatic analyses and all thermal analyses) — if Thermal Conductance = Manual. Electrical Conductance (Electric and Magnetostatic analyses) Electrical Conductance Value (Electric and Magnetostatic analyses) if Electric Conductance = Manual. Pinball Region Pinball Radius — if Pinball Region = Radius. Time Step Controls — if Type = Frictionless, Rough, or Frictional.

Basics of Contact Region object

Object Properties — Rigid Body Dynamics Analyses The Details view properties for this object include the following. Category Scope

Fields/Conditions Scoping Method Contact (p. 507) Target (p. 508) Contact Bodies (p. 508) Target Bodies (p. 508) Contact Shell Face (p. 508) — appears for surface bodies. Target Shell Face (p. 508) — appears for surface bodies.

Definition

Type

Advanced

Restitution Factor

Basics of Contact Region object

Contact Tool (Group) Determines contact conditions on an assembly both before loading and as part of the final solution. Applies to the following objects: Contact Tool, Frictional Stress, Gap, Initial Information, Penetration, Pressure, Sliding Distance, Status

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Contact Tool (Group) Tree Dependencies: • Valid Parent Tree Objects: – For Contact Tool: Connections, Solution – For Frictional Stress, Pressure, Sliding Distance, and Fluid Pressure: Contact Tool under Solution object – For Gap, Penetration, and Status: Contact Tool under Connections object or Solution object – For Initial Information: Contact Tool under Connections object only • Valid Child Tree Objects: – For Contact Tool under Connections object: Comment, Gap, Image, Initial Information, Penetration, Status – For Contact Tool under Solution object: Comment, Gap, Frictional Stress, Image, Penetration, Pressure, Sliding Distance, Fluid Pressure, Status – For Frictional Stress, Gap, Penetration, Pressure, Sliding Distance, and Fluid Pressure: Alert, Comment, Convergence, Figure, Image – For Initial Information: Comment, Image – For Status: Comment, Figure, Image Insertion Options: • For Contact Tool under Connections object, use any of the following methods after highlighting Connections object: – Choose Contact Tool on Connections context toolbar under the Contact drop down menu. – Click right mouse button on Connections object or in the Geometry window> Insert> Contact Tool. • For Contact Tool under Solution object, use any of the following methods after highlighting Solution object: – Choose Tools> Contact Tool on Solution context toolbar. – Click right mouse button on Solution object or in the Geometry window> Insert> Contact Tool> Contact Tool. • For any Contact Tool result object, use any of the following methods after highlighting Contact Tool object: – Choose Contact> (result object) on Contact Tool context toolbar. – Click right mouse button on Contact Tool object or in the Geometry window> Insert> (result object).

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Objects Reference Additional Related Information: • Connections Context Toolbar • Contact Overview • Contact Settings • Setting Contact Conditions Manually • Contact Ease of Use Features • Contact Tool and Results • Contact Options Preferences The following right mouse button context menu options are available for this object. • Generate Initial Contact Results — available for Contact Tool and all child objects when the Contact Tool is inserted under a Connections object. • Evaluate All Results — available for Contact Tool and all child objects when the Contact Tool is inserted under a Solution object.

Object Properties For more information on this object’s properties, see the Contact Tool section.

Convergence Controls the relative accuracy of a solution by refining solution results on a particular area of a model. The Convergence object is applicable to static structural, modal, linear buckling, steady-state thermal, and magnetostatic analyses. Tree Dependencies: • Valid Parent Tree Objects: Several result objects. Insertion Options: Click right mouse button on a result object or in the Geometry window> Insert> Convergence.

Note Only one Convergence object is valid per result object. Convergence is not supported: • For result objects that belong to linked analyses. • If an imported load object exists in the environment. • When Imported Layered Section or Imported Thickness objects are used.

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Coordinate System When running background solutions, only one maximum refinement loop is performed. Additional Related Information: • Adaptive Convergence • Error (Structural) • Error (Thermal) • Mechanical Options — Convergence

Object Properties The Details view properties for this object include the following. Category

Fields

Definition

Type Allowable Change

Results

Last Change — Read-only indication of the most recent change in convergence. Converged — Read-only indication of the convergence state (Yes or No).

Note • Convergence objects inserted under an environment that is referenced by an Initial Condition object or a Thermal Condition load object, will invalidate either of these objects, and not allow a solution to progress. • Results cannot be converged when you have a Mesh Connection object or a Pinch control with PinchBehavior set to Post. • To use Convergence, you must set Calculate Stress to Yes under Output Controls in the Analysis Settings details panel. However, you can perform Modal and Buckling Analysis without specifying this option. • You cannot use Convergence if you have an upstream or a downstream analysis link. • Convergence is not available when you import loads into the analysis.

Coordinate System Represents a local coordinate system that you can add under a Coordinate Systems object.

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Objects Reference Tree Dependencies: • Valid Parent Tree Object: Coordinate Systems • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: Use any of the following methods after highlighting Coordinate Systems object, or Global Coordinate System object, or another Coordinate System object: • Choose Create Coordinate System button on Coordinate Systems context toolbar. • Click right mouse button on Coordinate Systems object, or Global Coordinate System object, or another Coordinate System object, or in the Geometry window> Insert> Coordinate System. Additional Related Information: • Coordinate Systems • Creating Coordinate Systems

Object Properties The Details view properties for this object include the following. Category

Properties

Definition

Type Cartesian or Cylindrical. Coordinate System Program Controlled or Manual. These options assign the coordinate system reference number automatically or manually. If you specify Manual, the Coordinate System ID property displays. Enter a value greater than or equal to 12. Coordinate systems must have an unique ID. Suppressed Yes or No (default). Suppressing a coordinate system removes the object from further treatment, and writes no data to the input deck, and causes any objects scoped to the coordinate system to become underdefined (therefore invalidating solutions).

Origin

Define By Geometry Selection, Named Selection or Global Coordinates. • Geometry Selection — Default setting, indicating that the coordinate system is applied to a geometry or geometries, which are chosen using a graphical selection tools.

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Coordinate System When the Define By is set to Geometry Selection, the Geometry property displays. This property displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection: when this property is selected, the geometry selection is defined by a Named Selection. When the Define By is set to Named Selection, another Named Selection property displays. This field provides a drop-down list of available user-defined Named Selections. • Global Coordinates This selection allows you to specify the coordinate system origin using the Location property in tandem with the Hit Point Coordinate feature on the Graphics Toolbar or by entering Origin X, Origin Y, and Origin Z coordinate values directly to define the origin of the coordinate system. The following properties define the X, Y, and Z locations on the coordinate axis from the (0, 0, 0) location. • Origin X • Origin Y • Origin Z Axis: X, Y, or Z Define the Principal Axis vector with respect to one of these planes.

Principle Axis

Define By Property options include: Geometry Selection Fixed Vector Global X Axis Global Y Axis Global Z Axis Hit Point Normal Orientation About Principle Axis

Axis Based on the Principal Axis, define the Orientation About Principal Axis vector with respect to the X, Y, or Z plane. Define By Property options include: Default Geometry Selection Global X Global X

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Objects Reference Global X Fixed Vector Directional Vectors

The following Directional Vector properties are read-only mathematical representations, in matrix form, showing the orientation in space of the X, Y, and Z vectors. • X Axis Data • Y Axis Data • Z Axis Data

Transformations

The Transformations properties allow you to change the location and rotation of the original definition of the coordinate system. Shown below, these properties are order-dependent and that order may be modified using the Move Up and Move Down features of the Coordinate System Context Toolbar. • Base Configuration • Offset X • Offset Y • Offset Z • Rotate X • Rotate Y • Rotate Z • Flip X • Flip Y • Flip Z • Transformation Configuration

Coordinate Systems Houses any new coordinate systems that can include a Global Coordinate System object and local Coordinate System objects.

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Crack Tree Dependencies: • Valid Parent Tree Object: Model • Valid Child Tree Objects: Comment, Coordinate System, Figure, Global Coordinate System, Image Insertion Options: The Coordinate Systems object is automatically inserted into the tree.

Note Only one Coordinate Systems (Parent) object is valid per Model. Additional Related Information: • Coordinate Systems • Creating Coordinate Systems

Crack Defines a crack based on an internally generated mesh to analyze crack fronts by use of geometric parameters. Tree Dependencies: • Valid Parent Tree Object: Fracture Insertion Options: Click right mouse button on Fracture, Crack, or Pre-Meshed Crack object and select Insert> Crack. Additional Related Information: • Fracture Meshing • Fracture Analysis

The following right mouse button context menu options are available for this object. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Objects Reference • Insert>Crack • Insert>Pre-Meshed Crack • Generate All Crack Meshes • Suppress

Object Properties The Details view properties for this object include the following. Category

Properties

Scope

Source — Read-only and always set to Crack when defining cracks. Scoping Method — Read-only and always set to Geometry Selection when defining cracks. Geometry — Use the Body selection filter to pick a solid body, click in the Geometry field, then click Apply.

Definition

Coordinate System — Specifies the coordinate system that defines the position and orientation of the crack. The Y axis of the specified coordinate system defines the crack plane normal. You can select the default coordinate system or a local coordinate system that you have defined. The default is the Global Coordinate System. The valid coordinate system must be of type Cartesian and its origin cannot lie outside the bounding box of the body scoped to the crack. The X axis of the crack must be oriented to the surface normal and its origin must be located on the surface. For more information on creating a coordinate system aligned with a hit point, see Creating a Coordinate System Based on a Surface Normal (p. 487). Crack Shape — Read-only and always set to Semi-Elliptical. Major Radius — Specifies the major radius, which defines the size of the crack shape along the Z axis (that is, the width of the crack). The specified value must be greater than 0. Minor Radius — Specifies the minor radius, which defines the size of the crack shape along the X axis (that is, the depth of the crack). The specified value must be greater than 0. Fracture Affected Zone — The fracture affected zone is the region that contains a crack. The Fracture Affected Zone control determines how the fracture affected zone height is defined. When set to Program Controlled, the software calculates the height, and Fracture Affected Zone Height is read-only. This is the default. When set to Manual, you enter the height in the Fracture Affected Zone Height field. Fracture Affected Zone Height — This value specifies two things: 1) the height of the Fracture Affected Zone, which is in the Y direction of the crack coordinate system; and 2) the distance in totality by which the Fracture Affected Zone is extended in the positive and negative Z direction of the crack coordinate system from the crack front extremities. Largest Contour Radius — Specifies the largest contour radius for the crack shape. The specified value must be greater than 0. Circumferential Divisions — Specifies the number of circumferential divisions for the crack shape. The value must be a multiple of 8, and

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Direct FE (Group) Category

Properties must be 8 or greater. The default is 8. The Geometry window can display only a maximum of 360 circumferential divisions, but you can specify a higher value and fracture meshing will respect it. Mesh Contours — Specifies the number of mesh contours for the crack shape. The value must be 1 or greater. The default is 6. The Geometry window can display only a maximum of 100 mesh contours, but you can specify a higher value and fracture meshing will respect it. Crack Front Divisions — Specifies the number of divisions for the crack front. The value must be 3 or greater. The default is 15. The Geometry window can display only a maximum of 999 crack front divisions, but you can specify a higher value and fracture meshing will respect it. Solution Contours — Specifies the number of mesh contours for which you want to compute the fracture result parameters. The value must be less than or equal to the value of Mesh Contours, and cannot be greater than 99. By default, the value is Match Mesh Contours, indicating the number of Solution Contours is equal to the number of Mesh Contours. Entering 0 resets the value to Match Mesh Contours. Suppressed — Toggles suppression of the Crack object. The default is No. The Crack object is suppressed automatically if the scoped body is suppressed.

Buffer Zone Scale Factors

The Buffer Zone Scale Factors control the size of the buffer zone in the X, Y, and Z directions, relative to the size of the fracture affected zone. For each scaling parameter, use the slider to set a value from 2 to 50. The default is 2. The maximum dimension among the three directions of the fracture affected zone is multiplied by the corresponding scale factors to create a buffer zone: X Scale Factor Y Scale Factor Z Scale Factor

Named Selections Creation

Named Selections are created automatically when the fracture mesh is generated. These Named Selections are a special type of Named Selection. For details, refer to Fracture Meshing and Special Handling of Named Selections for Crack Objects. For information about Named Selections in general, refer to Named Selections (p. 429).

Direct FE (Group) Defines the node-based boundary conditions that are used in the Environment object of a model. Applies to the following objects: Nodal Orientation, Nodal Force, Nodal Pressure, Nodal Displacement, and Nodal Rotation.

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Objects Reference Tree Dependencies: • Valid Parent Tree Objects: Environment • Valid Child Tree Objects: – Nodal Orientation – Nodal Force – Nodal Pressure – Nodal Displacement – Nodal Rotation – EM Transducer Insertion Options: Use any of the following methods after highlighting Environment object: • Click Direct FE on Environment context toolbar. • Click right mouse button on Environment object or in the Geometry window; then Insert> {load type}.

Object Properties See the Direct FE section for more information about the load options as well as Details View properties.

End Release Allows chosen DOFs to be released on a vertex between line bodies. Tree Dependencies: • Valid Parent Tree Object: Connections • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: Use any of the following methods after highlighting Connections object: • Click End Release on Connections context toolbar. • Click right mouse button on Connections object or in the Geometry window; then Insert> End Release. Additional Related Information: • End Releases (p. 619)

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Environment (Group) • Connections Context Toolbar The following right mouse button context menu option is available for this object. • Rename Based on Definition (1) (1) — Description for Contact Region object also applies to Mesh Connection object. The Details view properties for this object include the following.

Object Properties The Details view properties for this object include the following. Category

Properties/Conditions

Scope

Scoping Method – Geometry Selection or Named Selection. Edge Geometry Vertex Geometry

Definition

Coordinate System Translation X Translation Y Translation Z Rotation X Rotation Y Rotation Z Behavior Suppressed

Environment (Group) An environment object holds all analysis related objects in a given Model object. The default name of the environment object is the same as the name of the analysis type. All result objects of an analysis are grouped under the Solution object.

Note The application creates reference files that contain analysis information that is read back into the application during solution processing. Certain textual characters can create issues during this reading process. Avoid the use of the following characters when renaming your environment: • Quote character (“) • Ampersand (&) • Apostrophe (‘) • Greater than and less than characters (< >)

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Objects Reference Tree Dependencies: • Valid Parent Tree Object: Model • Valid Child Tree Objects: Analysis Settings, Comment, Figure, Image, Initial Condition (for some analysis types), all load and support objects, Solution Insertion Options: Appears by default based on the analysis type chosen in the Project Schematic. Additional Related Information: • «Analysis Types» (p. 149) • Environment Context Toolbar • Types of Loads • Types of Supports The following right mouse button context menu options are available for this object. • Solve • Open Solver Files Directory — available for Windows OS only. • Clear Generated Data

Object Properties The Details view properties for this object include the following. Category

Properties

Definition read-only indications.

Physics Type Analysis Type Solver Target

Options

Environment Temperature — the temperature of the body unless this temperature is specified by a particular load such as a thermal condition or an imported temperature. This will also be the material reference temperature unless overridden by the Body (see Reference Temperature (p. 130) under Define Part Behavior (p. 129) for more information). Environment Temperature is not valid for any type of thermal analysis. Generate Input Only

Fatigue Tool (Group) Determines life, damage, and factor of safety information using a stress-life or strain-life approach. The Fatigue Tool is available only for Static Structural and Transient Structural analyses. Applies to the following objects: Biaxiality Indication, Damage, Damage Matrix, Equivalent Alternating Stress, Fatigue Sensitivity, Fatigue Tool, Hysteresis, Life, Rainflow Matrix, Safety Factor

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Fatigue Tool (Group) Tree Dependencies: • Valid Parent Tree Object: – For Fatigue Tool: Solution – For Biaxiality Indication, Damage, Damage Matrix, Equivalent Alternating Stress, Fatigue Sensitivity, Hysteresis, Life, Rainflow Matrix, Safety Factor: Fatigue Tool • Valid Child Tree Objects: – For Fatigue Tool: Biaxiality Indication, Comment, Damage, Damage Matrix, Equivalent Alternating Stress, Fatigue Sensitivity, Hysteresis, Image, Life, Rainflow Matrix, Safety Factor – For Biaxiality Indication, Damage, Equivalent Alternating Stress, Life, Safety Factor: Alert, Comment, Convergence, Figure, Image – For Damage Matrix, Fatigue Sensitivity, Hysteresis, Rainflow Matrix: Comment, Image Insertion Options: • For Fatigue Tool, use any of the following methods after highlighting Solution object: – Choose Tools> Fatigue Tool on Solution context toolbar. – Click right mouse button on Solution object or in the Geometry window> Insert> Fatigue> Fatigue Tool. • For all fatigue results under Fatigue Tool, use any of the following methods after highlighting Fatigue Tool object: – Choose Contour Results or Graph Results> [specific fatigue result] on Fatigue Tool context toolbar. – Click right mouse button on Fatigue Tool object or in the Geometry window> Insert> [specific fatigue result]. Additional Related Information: • Fatigue Overview • Mechanical Fatigue Material Properties • Fatigue Analysis and Loading Options • Reviewing Fatigue Results The following right mouse button context menu options are available for this object. • Evaluate All Results — available for Fatigue Tool and all child objects.

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Objects Reference

Object Properties The Details view properties for this object include the following. For the Fatigue Tool: Category

Properties

Materials

Fatigue Strength Factor (Kf)

Loading

Type Loading Ratio — appears only if Type is set to Ratio. History Data Location — appears only if Type is set to History Data. Scale Factor

Definition

Display Time — enter a time value (within the analysis time limit) to display results at that moment of the analysis.

Options

Analysis Type Mean Stress Theory Stress Component Bin Size — appears only if Type is set to History Data. Use Quick Rainflow Counting — appears only if Type is set to History Data. Infinite Life — appears if Analysis Type is set to Strain Life; or if Analysis Type is set to Stress Life and Type is set to History Data. Maximum Data Points To Plot — appears only if Type is set to History Data.

Life Units

Units Name 1 cycle is equal to

For Biaxiality Indication, Damage, Equivalent Alternating Stress, Life, Safety Factor: Category

Properties

Scope

Scoping Method Path Geometry — Use selection filters to pick geometry, click in the Geometry field, then click Apply.

Definition

Design Life — available for Damage and Safety Factor. Type — Read-only indication of fatigue object name. Use Average Identifier

Results — Readonly indication of the following quantities.

Minimum — available for Life, Safety Factor, Biaxiality Indication, Equivalent Alternating Stress. Minimum Occurs On — available for Life, Safety Factor, Biaxiality Indication, Equivalent Alternating Stress. Maximum — available for Damage, Biaxiality Indication, Equivalent Alternating Stress. Maximum Occurs On — available for Damage, Biaxiality Indication, Equivalent Alternating Stress.

Information available for Life and Equivalent Alternating

Time Load Step Substep Iteration Number

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Figure Stress. Read-only indication of the following quantities. For Damage Matrix, Fatigue Sensitivity, Hysteresis, Rainflow Matrix: Category

Properties

Scope

Geometry — Use selection filters to pick geometry, click in the Geometry field, then click Apply.

Definition available only for Damage Matrix and Fatigue Sensitivity.

Sensitivity For — available only for Fatigue Sensitivity. Design Life — available only for Damage Matrix; and Fatigue Sensitivity if Sensitivity For is set to Damage or Safety Factor.

General

Stress Strain Type — if set to Shear Stress, the General, Options, and Results categories are replaced by a Definition category that includes a Type setting.

Options

Lower Variation — available only for Fatigue Sensitivity. Upper Variation — available only for Fatigue Sensitivity. Number of Fill Points — available only for Fatigue Sensitivity. Chart Viewing Style — available only for Damage Matrix, Fatigue Sensitivity, and Rainflow Matrix. Points per Segment — available only for Hysteresis.

Results — available only for Damage Matrix, Hysteresis, and Rainflow Matrix. Read-only indication of the following quantities.

Minimum Range — available only for Damage Matrix and Rainflow Matrix. Maximum Range — available only for Damage Matrix and Rainflow Matrix. Minimum Mean — available only for Damage Matrix and Rainflow Matrix. Maximum Mean — available only for Damage Matrix and Rainflow Matrix. Minimum Strain — available only for Hysteresis. Maximum Strain — available only for Hysteresis. Minimum Stress — available only for Hysteresis. Maximum Stress — available only for Hysteresis.

Figure Captures any graphic displayed for a particular object in the Geometry window. A Figure object can be further manipulated (rotated for example), unlike an Image object, which is a static screen shot of the current model view or an imported static figure. Popular uses of a Figure object are for presenting specific views and settings for later inclusion in a report. Tree Dependencies: • Valid Parent Tree Object: All objects except Alert, Commands, Comment, Convergence, Image, Project, Result Tracker, Solution Combination, Solution Information • Valid Child Tree Objects: None Insertion Method: Click the New Figure or Image button on standard toolbar and select Figure. Additional Related Information: Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Objects Reference • Inserting Comments, Images, and Figures (p. 121) • Viewports • Reports • Standard Toolbar

Object Properties Caption is the only property available for the Figure object. It provides an editable text field.

Fluid Surface Fluid Surface objects allow you to identify faces that should be grouped together in support of a virtual body for assembly meshing.

Note Virtual Body and Fluid Surface objects are fluids concepts, and as such they are not supported by Mechanical solvers. Tree Dependencies: • Valid Parent Tree Objects: Virtual Body Insertion Options: Use any of these methods: Highlight the Virtual Body object, and then: • In the Details view for the Virtual Body, set Used By Fluid Surface to Yes. • Click the right mouse button and select Insert> Fluid Surface from the context menu. Additional Related Information: • Meshing Capabilities in Workbench • Mesh Context Toolbar • Assembly Meshing • Defining Virtual Bodies

Object Properties The Details view properties for this object include the following.

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Fracture Category

Properties

Scope

Faces To Group — Set of faces that should be members of the group. Master Virtual Body — Read-only name of the master Virtual Body. Priority — Determines which group will claim cells in cases where groups overlap. The priority is initially based on the rule: the smaller the volume, the higher the priority.

Definition

Suppressed — Read-only setting inherited from the Virtual Body.

Fracture Represents all definitions of cracks within a model. Each definition is represented in a Crack or PreMeshed Crack object, where a Crack is generated internally within the Mechanical application or Meshing application, while a Pre-Meshed Crack comes from an external source. May contain any number of Crack or Pre-Meshed Crack objects. Tree Dependencies: • Valid Parent Tree Object: Model • Valid Child Tree Objects: Crack, Pre-Meshed Crack, Interface Delamination, Contact Debonding Insertion Options: Click right mouse button on Model object and select Insert> Fracture.

Note Only one Fracture object is valid per Model, and once it is inserted, it cannot be deleted. Additional Related Information: • Fracture Meshing • Fracture Analysis • Interface Delamination and Contact Debonding The following right mouse button context menu options are available for this object. • Insert>Crack • Insert>Pre-Meshed Crack • Generate All Crack Meshes • Insert>Contact Debonding Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Objects Reference

Gasket Mesh Control Available when Body object’s Stiffness Behavior is set to Gasket. The control applies a sweep mesh in a chosen direction and drops midside nodes on gasket elements that are parallel to the sweep direction. Tree Dependencies: • Valid Parent Tree Object: Body • Valid Child Tree Objects: None. Insertion Options: Appears automatically when a Body object’s Stiffness Behavior is set to Gasket. Additional Related Information: • Gaskets (p. 480)

Object Properties The Details view properties for this object include the following. Category

Properties

Definition

Free Face Mesh Type Mesh Method Element Midside Nodes

Scope

Src/Trg Selection Source Target

Geometry Represents attached geometry in the form of an assembly or multibody part from a CAD system or from DesignModeler. Assembly parameters, if available, are viewable under the Geometry object. Tree Dependencies: • Valid Parent Tree Object: Model • Valid Child Tree Objects: Comment, Figure, Image, Layered Section, Part, Point Mass, Thickness Insertion Options: Appears by default with a Model object. Additional Related Information: • «Specifying Geometry in the Mechanical Application» (p. 371) 1336

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Geometry • Attach Geometry The following right mouse button context menu options are available for this object. • Search Faces with Multiple Thicknesses • Update Geometry from Source • Reset Body Colors • Show Missing Tessellations • Insert > Virtual Body

Note Virtual Body and Fluid Surface objects are fluids concepts, and as such they are not supported by Mechanical solvers.

Object Properties The Details view properties for this object include the following. Category Definition

Properties Source — Read-only indication of the path and file name associated with the geometry. Type — Read-only indication of how the original geometry was created (CAD product name or DesignModeler). Length Unit — Read-only indication of the length unit originally assigned to the geometry. Exceptions are when importing geometry from CATIA V5 or ACIS, where length units must be specified from a drop down menu. Element Control — Allows manual control of the underlying Mechanical APDL element options (KEYOPTS) for individual Part or Body objects beneath the Geometry object. To manually set Mechanical APDL element options, set Element Control to Manual, then select the Part or Body object. Any element options that are available for you to manually set appear in the Details view of the Part or Body object. For example, the Brick Integration Scheme setting for a Part or Body object becomes available only when Element Control is set to Manual. When Element Control is set to Program Controlled, all element options are automatically controlled and no settings are displayed. The Mechanical APDL application equivalent to this setting is the inclusion of the ETCON,SET command in the input file, which automatically resets options for currenttechnology elements to optimal settings. Refer to the Mechanical APDL Element Reference in the Mechanical APDL Help for more information about Mechanical APDL elements and element options. Display Style — The default is Body Color which assigns unique colors to individual bodies in a part. Other choices include Part Color, Material, Non linear Material Effects, and Stiffness Behavior. 2D Behavior — Appears only for a designated 2-D simulation. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Objects Reference Category

Properties

Bounding Box

Length X Length Y Length Z

Properties

Volume Mass — Appears only in the Mechanical application. Any suppressed Part or Body child objects are not included in the mass property values that are displayed.

Note If the material density is temperature dependent, the Mass will be computed at the body temperature, or at 22oC (default temperature for an environment). Scale Factor Value — The factor applied to imported geometry for the purpose of modifying the size of the model. The scale factor value of newly imported geometry is 1.0. You can modify the value and that value is expected to be preserved on updated models. Due to tolerances, models that are scaled (especially larger) sometimes have problems meshing. The scale factor limit is from 1e-3 to 1e3. Factors entered beyond that range are ignored.

Note • Beam sections and shell thicknesses are not affected by the Scale Factor Value. • Geometry scale factors should not be applied after virtual cells have been added to the model. Doing so may result in mesh failure.

Statistics: — Readonly indication of the entities that comprise the geometry. Active Bodies are those that are unsuppressed compared to the total number of Bodies.

Bodies Active Bodies Nodes Elements Mesh Metric

Basic Geometry Options

Solid Bodies Surface Bodies Line Bodies Parameters Parameter Key Attributes Named Selections

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Global Coordinate System Category

Properties Material Properties Use Associativity Coordinate Systems Reader Mode Saves Updated File Use Instances Smart CAD Update Compare Parts on Update Attach File Via Temp File Temporary Directory Analysis Type Mixed Import Resolution Decompose Disjoint Geometry Enclosure and Symmetry Processing

Advanced Geometry Options

Global Coordinate System Represents the default coordinate system. The origin is defined as 0,0,0 in the model coordinate system. This location serves as the reference location for any local Coordinate System objects inserted under the Global Coordinate System object. Tree Dependencies: • Valid Parent Tree Object: Coordinate Systems • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: Automatically inserted in the tree. Additional Related Information: • Coordinate Systems • Creating Coordinate Systems

Object Properties The Details view properties for this object include the following. The following are all read-only status indications of the global coordinate system: Category

Properties

Definition

Type Mechanical APDL System Number — assigns the coordinate system reference number (the first argument of the Mechanical APDL LOCAL command).

Origin

Origin X Origin Y Origin Z Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Objects Reference Category Directional Vectors

Properties X Axis Data Y Axis Data Z Axis Data

Image Inserts a screen shot of the model in its current view or imports any image in .bmp, .jpg, or png format under a parent object. Its use is similar to inserting a Comment object. Inserted images appear in the Report. Image is a static picture of the current model view. It differs from the Figure object, which is also a picture of the current model view that can be further manipulated (rotated for example).

Note Duplicating an image in the tree will result in both the original object and the copied object using the same image file on disk. Altering or deleting either the original or the copied object will result in modification and/or deletion of the image file on disk. Both items in the tree will be affected by the change to one of the objects. Tree Dependencies: • Valid Parent Tree Objects: – For importing images: All objects – For static image captures: Same parent tree objects as for Figure • Valid Child Tree Object: Comment Insertion Method: Click the New Figure or Image button on the standard toolbar and select Image. For importing an image, choose Image from File, then choose an image file from the browse window. Filters are available for listing only image files in .bmp, .jpg, or.png formats. Additional Related Information: • Inserting Comments, Images, and Figures (p. 121) • Reporting

Imported Layered Section Imported Layered Section objects provide layer data that has been made available from an external system upstream of the analysis system.

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Imported Layered Section Tree Dependencies: • Valid Parent Tree Objects: Model • Valid Child Tree Object: Comment, Image Insertion Method: • Appears automatically when importing layer data from an external system. Additional Related Information: • Specifying Surface Body Layered Sections (p. 383)

Object Properties The Details view properties for this object include the following. Category Definition

Properties Type — appears as Imported Layered Section and is a read-only field. Suppressed — select Yes to suppress this object.

Note Suppression option is only available when the external system shares the model with the downstream analysis system. Material

Nonlinear Effects — select yes to include the nonlinear effects from the material properties. The reference temperature specified for the body on which a layered section is defined is used as the reference temperature for the layers. Thermal Strain Effects — select yes to send the coefficient of thermal expansion to the solver.

Note These fields are not supported for an Explicit Dynamics analysis. Graphic Properties

Layer to Display — defines which layer to display on the model. For information on setting the Layer to Display see Viewing Individual Layers (p. 384). Note that the layer number will correspond to the layer number used by the Mechanical APDL solver, which

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Objects Reference may not match the layer number of the system providing the layered data.

Note This property is only available when the external system shares the model with the downstream analysis system.

Imported Load (Group) The Imported Load group includes the loads that you have imported from an earlier analysis and want to apply in the present analysis. You can add valid loads under the Imported Load object folder. Applies to: Imported Load object folder and all imported load child objects under the folder. Tree Dependencies: • Valid Parent Tree Objects: Any Environment object. • Valid Child Tree Object: Comment, Image, imported load objects Insertion Method: Appears by default for specific analyses with data transfer. Additional Related Information: • Imported Loads

Object Properties The Details view properties for the Imported Load object folder include the following. Category

Properties

Definition

Type — read-only indication. Interpolation Type — read-only indication. Suppressed

The Details view properties for the imported load object include the following.

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Imported Remote Loads Category

Properties

Scope

Scoping Method Geometry – appears if Scoping Method is set to Geometry Selection. In this case, use selection filters to pick geometry, click in the Geometry field, then click Apply. Named Selection – appears if Scoping Method is set to Named Selection.

Definition

Type — read-only indication of imported load. Suppressed

Display

Preview Row — appears if multiple load steps are used.

Imported Remote Loads The Imported Remote Loads object includes the Force and Moment boundary conditions provided by an upstream Maxwell analysis to perform a coupled simulation. These loading conditions are used during a Harmonic Response analysis.

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Objects Reference Tree Dependencies: • Valid Parent Tree Objects: Environment (Group) • Valid Child Tree Object: the automatically generated groups of remote forces and moments. Insertion Method:: Appears by default for specific analyses with data transfer. Additional Related Information: • Importing Data into a Harmonic Analysis • Electromagnetics (EM) — Mechanical Data Transfer

Note As illustrated, an Imported Remote Loads object is automatically generated it contains Remote Point objects that are automatically named and associated with an appropriate group for the Force and Moment loading objects.

Object Properties The Details view properties for the Imported Remote Loads object folder include the following. Category

Properties

Scope

Scoping Method: options include: • Geometry Selection: this is the default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using graphical selection tools. Geometry: visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of

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Imported Thickness Category

Properties geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. • Named Selection: indicates that the geometry selection is defined by a Named Selection. Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user-defined Named Selections.

Definition

Ansoft Solution: this property provides a drop-down list of the available solutions that were generated in the upstream application. When multiple solutions are available, your selection defines which solution data is applied to the imported load. Remote Points: this property provides the options Internal and Globally Available. On Data Refresh: this option is available only when the Remote Points property is set to Globally Available. Its options include: • Reuse Remote Points: this is the default setting. This option reuses the previously added remote points and only updates the scoping and location, if necessary. • Regenerate Remote Points: this option deletes the remote points that were created during the previous import and adds new remote points when the data is imported. Import Status: this read-only property displays the status of the import. Status conditions include the following: • Data Unavailable: no data is available to perform the import. • Obsolete: the data is available to be imported, but no data has been imported or the data is obsolete and should be re-imported. • Update: all data has been imported. • Import Failed: an error occurred during the import process and no data was imported Suppressed: the default value is No.

Imported Thickness Use the Imported Thickness object to import thickness data generated in a previous analysis for application in a current analysis. Imported Thickness objects are created in Mechanical by linking an External Data system to an analysis’ Model cell in the Project Schematic by right-clicking Setup>Transfer Data To New and selecting an analysis type for the External Data system in the Project Schematic. You can also right-click the Model cell of your project on the Project Schematic and select Transfer Data From New>External Data. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Objects Reference Solver Notes: • For the MAPDL solver, thickness on 3D shells is represented at the nodal level via the SECFUNCTION command. For 2D plane stress, thicknesses are calculated as an average value from the element’s nodal thickness values and it is input as a real constant for the element. • For the Explicit Dynamics solver the element’s nodal thicknesses are converted to an average element thickness. • For Explicit Dynamics (LS-DYNA Export) analyses, thicknesses are applied to the nodes. This is also true for 2D analyses. Applies to: Imported Thickness object folder and all thickness child objects under the folder. Tree Dependencies: • Valid Parent Tree Objects: Imported Thickness Group • Valid Child Tree Object: Comment, Image Insertion Method: • Appears by default for specific analyses with data transfer • Click right mouse button on the Imported Thickness Group object • Click on Thickness in the Geometry toolbar. Additional Related Information: • External Data Import (p. 310) • Specifying Surface Body Thickness (p. 380) • Polyflow to Mechanical Data Transfer (p. 325) The following right mouse button context menu options are available for this object. • Search Faces with Multiple Thicknesses

Object Properties The Details view properties for this object include but are not limited to the following. See Appendix B. Data Transfer Mesh Mapping for additional information about other categories and settings for Imported Thicknesses. Category

Properties

Scope

Scoping Method — Select the method of choosing objects to which the thickness is applied: Geometry Selection or Named Selection.

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Imported Thickness (Group) Geometry – appears if Scoping Method is set to Geometry Selection. In this case, use selection filters to pick geometry, click in the Geometry field, then click Apply. Named Selection – appears if Scoping Method is set to Named Selection. Definition

Type — appears as Imported Thickness and is a read-only field. Suppressed — Select Yes to suppress Imported Thickness. External Data Identifier — Choose the appropriate data identifier which represents the thickness data from the file. Scale — The amount by which the imported thickness values are scaled before being used for display or solution. Offset — An offset that is added to the imported thickness values before being used for display or solution. Shell Offset — Set the desired shell offset.

Advanced

Unmapped Data Value — You can specify a thickness value for the unmapped target nodes using the Unmapped Data Value property. By default, a zero thickness value is assigned to the unmapped nodes. For the ANSYS solver, the thickness value at each node must be greater than zero. See External Data Import in the ANSYS Mechanical User’s Guide for details.

Imported Thickness (Group) The External Thickness group includes the thicknesses that you have imported from an earlier analysis and want to apply in the present analysis. You can add valid thicknesses under the Geometry > Imported Thickness object folder by right-clicking the Imported Thickness or the Thickness objects. For a 3D analysis, imported data is specified as a shell thickness but for a 2D analysis, it is defined as a plane element thickness. Plane element thicknesses are calculated as an average value from nodal thickness values and it is input as a real constant for the element. Applies to: Imported Thickness object folder and all external thickness child objects under the folder.

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Objects Reference Tree Dependencies: • Valid Parent Tree Objects: Geometry object. • Valid Child Tree Object: Comment, Image, imported thickness objects Insertion Method: • Appears by default when a Mechanical Model cell is connected to an External Data system. • Create a link to an upstream Polyflow system. Additional Related Information: • External Data Import (p. 310) • Polyflow to Mechanical Data Transfer (p. 325)

Object Properties The Details view properties for the Imported Thickness object folder include the following. Category

Properties

Definition

Type A read-only description of the Imported Thickness property. Interpolation Type A read-only description of the Interpolation Type property. Suppressed Enables you to control whether the Imported Thickness characteristics are considered in the solving of the simulation.

Initial Conditions Houses initial condition objects for use in a Transient Structural analysis (Velocity only) or an explicit dynamics analysis (Velocity and Angular Velocity).

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Initial Temperature Tree Dependencies: • Valid Parent Tree Object: Transient Structural [for Velocity only], or Explicit Dynamics environment object [for either Velocity or Angular Velocity]. • Valid Child Tree Objects: Angular Velocity (Explicit Dynamics object only), Comment, Figure, Image, Pre-Stress (Explicit Dynamics object only), Velocity Insertion Options: Appears by default for a Transient Structural analysis or an explicit dynamics analysis. Additional Related Information: • Define Initial Conditions • Transient Structural Analysis (p. 285) • Explicit Dynamics Analysis (p. 155)

Initial Temperature Defines an initial temperature or an initial temperature distribution for use in a steady-state thermal or transient thermal analysis.

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Objects Reference Tree Dependencies: • Valid Parent Tree Object: Steady-State Thermal or Transient Thermal analysis environment. • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: Appears by default for a steady-state thermal analysis or a transient thermal analysis. Additional Related Information: • Define Initial Conditions • Steady-State Thermal Analysis (p. 277) • Transient Thermal Analysis (p. 297)

Object Properties The Details view properties for this object include the following. Category

Properties

Definition

Initial Temperature Initial Temperature Value

Interface Delamination The Interface Delamination object allows you to simulate the separation of two materials across an interface.

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Interface Delamination Tree Dependencies: • Valid Parent Tree Object: Fracture Insertion Options: Use any of the following methods after highlighting Fracture object: • Click the Interface Delamination button on the Fracture context toolbar. • Click right mouse button on the Fracture object, Interface Delamination object, or Contact Debonding object and select Insert>Interface Delamination. Additional Related Information: • Interface Delamination and Contact Debonding • Fracture Analysis • Crack • Pre-Meshed Crack The following right mouse button context menu options are available for this object. • Insert>Interface Delamination • Insert>Contact Debonding • Suppress

Object Properties The Details view properties for this object include the following. Category

Properties

Definition

Type — read-only field that describes the object — Interface Delamination. Method — this property specifies the formulation used to introduce the fracture mechanism, either Virtual Crack Closure Technique (VCCT — default) or Cohesive Zone Material (CZM). Failure Criteria Option — options include: • Energy-Release rate — this property displays when VCCT is the specified as Method. It requires you to specify a Critical Rate value. This value determines the energy release rate in one direction. • Material Data Table — — this property displays when VCCT is the specified as Method. This property defines the energy release rate in all three fracture modes. It provides a fly-out menu for Material selection or specification. Material definitions are created in Engineering Data. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Objects Reference Category

Properties Material — this property displays when CZM is the specified as Method. It provides a fly-out menu for Material selection or specification. Material definitions are created in Engineering Data. Suppressed — this property allows you to exclude the object in the analysis.

Scope

Generation Method — specify as either Matched Meshing or Node Matching. If interface layers imported from ANSYS Composite PrepPost (ACP) application are available, a third option, Pre-Generated Interface is also available. This property is automatically set to Pre-Generated Interface for Interface Delamination objects automatically generated during the import process for the interface layers. Scoping Method — displayed when Node Matching is specified as the Generation Method. Options include Geometry Selection (default) and Named Selection. Specifies that the Source and Target properties are defined using the graphical selection tools or that the geometry is defined by from a drop-down list of available user–defined Named Selections. This option assumes that the existing mesh is already matched. Source — displayed when Node Matching is specified as the Generation Method. Specify the face on the model that will be the source. Target — displayed when Node Matching is specified as the Generation Method. Specify the face on the model that will be the target. Match Control — displayed when Matched Meshing is specified as the Generation Method. The Match Control property references a pre-defined Mesh Match Control. The pre-defined Match Control requires two independent parts that have the same (brick) element/node pattern. Initial Crack — this property displays when VCCT is specified as Method. Select a user-defined Pre-Meshed Crack. Interface (ACP Only) — This property is only available when you create your composite geometry in the ACP application. Select the appropriate Interface Layer from the provided drop-down menu.

Step Controls for Crack Growth

This category displays when VCCT is specified as Method. It provides the following properties. If Auto Time Stepping is set to Manual the time step properties can be modified, otherwise they are read-only. Auto Time Stepping — options include Program Controlled (default) or Manual. Initial Time Step — initial time step when crack growth initiates. Minimum Time Step — minimum time step for subsequent crack growth. Maximum Time Step — maximum time step for subsequent crack growth.

Node Matching Tolerance

This category displays when Node Matching is specified as Generation Method. It provides the following properties. Tolerance Type — options include Program Controlled (default) or Manual.

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Joint Category

Properties Distance Tolerance — this property may be modified when the Tolerance Type is set to Manual, otherwise it is read-only — that is, the value is defined by the application. Node matching requires that each node has a corresponding mate (Source and Target). This tolerance value defines the search radius for determining the matching between Source and Target nodes.

Joint Defines conditions for reference and mobile pairs that make up a joint. Several Joint objects can appear as child objects under a Connection Group object. The Connection Group object name automatically changes to Joints. Tree Dependencies: • Valid Parent Tree Object: Connection Group • Valid Child Tree Objects: Comment, Coordinate System, Figure, Image Insertion Options: Use any of the following methods after highlighting Connections object: • Inserted automatically if joints are defined in the CAD model and you choose Create Automatic Connections through a right mouse button click on the Connections (or Joints) object. • Click Body-Ground> {type of joint} or Body-Body> {type of joint} on Connections context toolbar. • Click right mouse button on Connections (or Joints ) object in the Geometry window> Insert> Joint. Additional Related Information: • Joints (p. 542) • Joint Load (p. 742) • Connections Context Toolbar The following right mouse button context menu options are available for this object. • Enable/Disable Transparency • Hide All Other Bodies • Flip Reference/Mobile • Search Connections for Duplicate Pairs • Go To Connections for Duplicate Pairs — available if connection object shares the same geometries with other connection objects. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Objects Reference • Promote to Remote Point (Remote Attachment Only) • Promote to Named Selection • Rename Based on Definition

Object Properties For more information on this object’s properties, see the Joint Properties (p. 553) section for specific details.

Layered Section Allows you to define layered section properties on selected surface bodies or on selected faces of surface bodies. Tree Dependencies: • Valid Parent Tree Object: Geometry • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: Use any of the following methods after highlighting Geometry object : • Click Layered Section button on Geometry context toolbar. • Click right mouse button on Geometry object > Insert> Layered Section. Additional Related Information: • Specifying Surface Body Layered Sections (p. 383) • Geometry Context Toolbar The following right mouse button context menu options are available for this object. • Search Faces with Multiple Thicknesses

Object Properties The Details view properties for this object include the following. Category

Properties

Scope

Scoping Method

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Loads, Supports, and Conditions (Group) Geometry — appears if Scoping Method is set to Geometry Selection. In this case, use selection filters to pick geometry, click in the Geometry field, then click Apply. Named Selection — appears if Scoping Method is set to Named Selection. Definition

Coordinate System Offset Type (this field is not supported for an Explicit Dynamics analysis) Membrane Offset — appears if Offset Type is set to User Defined. Layers — click here to open the worksheet to enter the layer data. Suppressed

Material

Nonlinear Effects — select yes to include the nonlinear effects from the material properties. The reference temperature specified for the body on which a layered section is defined is used as the reference temperature for the layers. Thermal Strain Effects — select yes to send the coefficient of thermal expansion to the solver.

Note These fields are not supported for an Explicit Dynamics analysis. Graphic Properties

Layer to Display — defines which layer to display on the model.

Properties

Total Thickness — total thickness of all of the layers in the Layered Section. Total Mass — total mass of all of the layers in the Layered Section.

Loads, Supports, and Conditions (Group) Defines the individual loads, supports, and conditions used as boundary conditions in the environment for a model. Applies to the following objects: Acceleration, Bearing Load, Bolt Pretension, Compression Only Support, Conductor, Constraint Equation, Convection, Coupling, Current, Cylindrical Support, Detonation Point, Displacement, Elastic Support, Nodal Displacement, Nodal Rotation, Fixed Rotation, Fixed Support, Fluid Solid Interface, Force, Frictionless Support, Generalized Plane Strain, Heat Flow, Heat Flux, Hydrostatic Pressure, Impedance Boundary, Internal Heat Generation, Joint Load, Line Pressure, Magnetic Flux Parallel, Moment, Nodal Orientation , Nodal Force, Nodal Pressure, Perfectly Insulated, Pipe Idealization, Pipe Pressure, Pipe Temperature, Pressure, PSD Base Excitation, Radiation, Remote Displacement, Remote Force, Rotational Velocity, RS Base Excitation, Simply Supported, Standard Earth Gravity, Temperature, Thermal Condition, Velocity, Voltage

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Objects Reference Tree Dependencies: • Valid Parent Tree Object: – For Magnetostatic Analysis only: Source Conductor when specifying a Current or Voltage – For all other objects: an analysis environment object. • Valid Child Tree Objects: – For Magnetostatic Analysis Source Conductor: Comment, Current, Figure, Image, Voltage (Solid Source Conductor only) – For all other objects: Comment, Figure, Image Insertion Options: • For Current or Voltage, scope to a body, then use any of the following methods: – Choose Conductor or Current on Environment context toolbar, then choose Current or Voltage from the toolbar. – Click right mouse button on Magnetostatic object, or in the Geometry window> Insert> Conductor then > Insert> Current or Voltage • For all other objects, use any of the following methods after highlighting Environment object: – Choose Inertial, or Load, or Supports, or Conditions> {Load, support, or condition name} on Environment context toolbar. – Click right mouse button on Environment object, any load, support, or condition object, or in the Geometry window> Insert> {Load, support, or condition name} Additional Related Information: • Create Analysis System • Apply Loads and Supports The right mouse button context menu option Promote to Named Selection is available for most boundary condition objects.

Object Properties See the Applying Boundary Conditions section for more information about Loads, Supports, and Conditions.

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Mesh

Mesh Manages all meshing functions and tools for a model; includes global controls that govern the entire mesh. Tree Dependencies: • Valid Parent Tree Object: Model • Valid Child Tree Objects: all mesh control tool objects, Comment, Figure, Image Insertion Options: Appears by default when geometry is attached. Additional Related Information: • Meshing Capabilities in Workbench • Mesh Context Toolbar

The following right mouse button context menu options are available for this object. • Update • Generate Mesh • Preview> Surface Mesh • Preview> Inflation • Show> Removable Loops • Show> Sweepable Bodies • Show> Mappable Faces • Show> Geometry in Overlapping Named Selections • Show> Program Controlled Inflation Surfaces • Create Pinch Controls • Clear Generated Data

Object Properties The Details view properties for this object include the following. Category Defaults

Fields Physics Preference Solver Preference (appears if Physics Preference is CFD)

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Objects Reference Category

Fields Relevance

Note Solver Preference also appears in the Mechanical application if the Physics Preference is Mechanical in a Transient Structural or Rigid Dynamics system during the initial geometry attach. See Solver Preference for more information. Sizing

Use Advanced Size Function Relevance Center Element Size Initial Size Seed Smoothing Transition Span Angle Center Curvature Normal Angle Proximity Accuracy Num Cells Across Gap Proximity Size Function Sources Min Size Proximity Min Size Max Face Size Max Size Growth Rate Minimum Edge Length

Inflation

Use Automatic Inflation Inflation Option Transition Ratio Maximum Layers Growth Rate Number of Layers Maximum Thickness First Layer Height First Aspect Ratio Aspect Ratio (Base/Height) Inflation Algorithm View Advanced Options Collision Avoidance Fix First Layer Maximum Height over Base Gap Factor Growth Rate Type Maximum Angle Fillet Ratio Use Post Smoothing Smoothing Iterations

Assembly Meshing

Method

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Mesh Connection Category

Fields Feature Capture Tessellation Refinement Keep Solid Mesh

Patch Conforming Options

Triangle Surface Mesher

Advanced

Shape Checking Element Midside Nodes Straight Sided Element — appears if the model includes an enclosure from DesignModeler. Number of Retries Extra Retries For Assembly Rigid Body Behavior Mesh Morphing

Defeaturing

Use Sheet Thickness for Pinch Pinch Tolerance Generate Pinch on Refresh Sheet Loop Removal Loop Removal Tolerance Defeaturing Tolerance

Statistics

Nodes — Read-only indication Elements — Read-only indication Mesh Metric

Mesh Connection Defines conditions for joining meshes of topologically disconnected surface bodies. Several Mesh Connection objects can appear as child objects under a Connection Group object. The name of the Connection Group object automatically changes to Mesh Connections. Tree Dependencies: • Valid Parent Tree Object: Connection Group • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: Use any of the following methods after highlighting Connections or Connection Group object: • Inserted automatically if you choose Create Automatic Connections through a right mouse click on the Connections or Mesh Connections objects. • Click Mesh Connection on Connections context toolbar.

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Objects Reference • Click right mouse button on Connections (or Mesh Connections) object or in the Geometry window; then Insert> Manual Mesh Connection. Additional Related Information: • Mesh Connection • Automatically Generated Connections • Connections Context Toolbar • Common Connections Folder Operations for Auto Generated Connections (p. 501) The following right mouse button context menu options are available for this object. • Enable/Disable Transparency (1) • Hide All Other Bodies (1) • Flip Master/Slave (1) • Search Connections for Duplicate Pairs (1) • Go To Connections for Duplicate Pairs (1) — available if connection object shares the same geometries with other connection objects. • Rename Based on Definition (1) (1) — Description for Contact Region object also applies to Mesh Connection object.

Object Properties The Details view properties for this object include the following. Category

Fields/Conditions

Scope

Scoping Method – Geometry Selection or Named Selection. Master Geometry Slave Geometry Master Bodies — read-only indication. Slave Bodies — read-only indication.

Definition

Scope Mode — read-only indication of Manual or Automatic. Tolerance Type Tolerance Slider — appears if Tolerance Type = Tolerance Slider. Tolerance Value — appears if Tolerance Type = Tolerance Slider (readonly) or Tolerance Value. Thickness Scale Factor — appears if Tolerance Type = Use Sheet Thickness. Suppressed Snap to Boundary Snap Type — appears if Snap to Boundary = Yes. Snap Tolerance — appears if Snap Type = Manual Tolerance.

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Mesh Control Tools (Group) Category

Fields/Conditions Master Element Size Factor — appears if Snap Type = Element Size Factor.

Mesh Control Tools (Group) Objects available for fine tuning the mesh. Applies to the following objects: Method, Mesh Grouping, Sizing, Contact Sizing, Refinement, Mapped Face Meshing, Match Control, Pinch, Inflation, Sharp Angle, Gap Sizing, Gap Tool Tree Dependencies: • Valid Parent Tree Object: – For Gap Sizing: Gap Tool – For all other objects: Mesh • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: • For Gap Sizing, automatic insertion under the Gap Tool based on detection of gap face pairs. • For all other objects, use any of the following methods after highlighting Mesh object: – Choose Mesh Control> {Mesh control tool name} on Mesh context toolbar. – Click right mouse button on Mesh object, any mesh control tool object, or in the Geometry window> Insert> {Mesh control tool name}. Additional Related Information: • Meshing Capabilities in Workbench • Mesh Context Toolbar • Gap Tool Context Toolbar — applicable to Gap Sizing and Gap Tool • Convergence — applicable to Refinement • Error (Structural) — applicable to Refinement The following right mouse button context menu options are available. Availability is dependent on the selected object.

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Objects Reference • Inflate This Method — available only for Method control where Method is set to anything other than Hex Dominant, MultiZone Quad/Tri, or Sweep (unless a source has been specified). • Update • Generate Mesh • Preview> Surface Mesh • Preview> Source and Target Mesh • Preview> Inflation • Show> Sweepable Bodies • Show> Mappable Faces • Create Gap Sizes — available only for Gap Tool • Rename Based on Definition

Object Properties The Details view properties for this object include the following. Except where noted, the following applies to all objects other than Gap Tool: Category Scope

Definition

Fields Scoping Method — specify either Geometry Selection or Named Selection. Not applicable to Contact Sizing, Gap Sizing, Pinch, or Match Control. Geometry — appears if Scoping Method is set to Geometry Selection. In this case, use selection filters to pick geometry, click in the Geometry field, then click Apply. Not applicable to Contact Sizing, Gap Sizing, Pinch, or Match Control. Named Selection — appears if Scoping Method is set to Named Selection. Not applicable to Contact Sizing, Gap Sizing, Pinch, or Match Control. Contact Region — applicable only to Contact Sizing. Suppressed

Note Additional Definition settings may be available, depending on the specific mesh control tool.

The following applies only to the Gap Tool: Category Definition

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Mesh Group (Group) Category

Fields Maximum Gap Aspect Ratio Gap Density Generate on Update

Mesh Group (Group) Mesh Group objects allow you to identify bodies that should be grouped together for assembly meshing. Also see the description of the Fluid Surface (p. 1334) object (applicable to assembly meshing algorithms only).

Note Virtual Body and Fluid Surface objects are fluids concepts, and as such they are not supported by Mechanical solvers. Tree Dependencies: • Valid Parent Tree Objects: Mesh Grouping Insertion Options: Highlight the Mesh object (or its Mesh Grouping or Mesh Group child object if any exist), and then: • Select Mesh Control> Mesh Group on the Mesh Context Toolbar. • Click the right mouse button on the object you highlighted and select Insert> Mesh Group from the context menu. These methods insert a Mesh Group object beneath the Mesh Grouping object. The Mesh Grouping object is inserted automatically when the first Mesh Group object is inserted. Additional Related Information: • Meshing Capabilities in Workbench • Mesh Context Toolbar • Defining Mesh Groups • Assembly Meshing

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Objects Reference

Object Properties The Details view properties for this object include the following. Category

Fields

Scope

Bodies To Group — Set of bodies that should be members of the group. All bodies within a group, including the Master Body, should be of the same type (i.e., Fluid or Solid, as defined by the Fluid/Solid material property). Otherwise, unexpected results may occur. Surface bodies cannot be selected for grouping. Master Body — Body that should act as the master of the group. The master body is the body to which all mesh of the group members will be associated. By default, the first body that is selected for Bodies To Group is the Master Body. Priority — Determines which group will claim cells in cases where groups overlap. The priority is initially based on the rule: the smaller the volume, the higher the priority.

Definition

Suppressed — Toggles suppression of the selected group. The default is No. If set to Yes, the group will be suppressed.

Mesh Grouping Represents all definitions of mesh groups within a model. Each definition is represented in a Mesh Group object. May contain any number of Mesh Group objects, which are used for assembly meshing. Tree Dependencies: • Valid Parent Tree Object: Mesh • Valid Child Tree Object: Mesh Group Insertion Options: Automatically inserted in the tree when the first Mesh Group object is inserted. Additional Related Information: • Meshing Capabilities in Workbench • Mesh Context Toolbar • Defining Mesh Groups • Assembly Meshing

Mesh Numbering Folder object that includes any number of Numbering Control objects, used for mesh numbering, which allows you to renumber the node and element numbers of a generated meshed model consisting of flexible parts.

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Modal Tree Dependencies: • Valid Parent Tree Object: Model • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: Use any of the following methods after selecting Model object: • Click Mesh Numbering button on Model context toolbar. • Click right mouse button on Model object or in the Geometry window> Insert>Mesh Numbering. Additional Related Information: • Mesh Numbering • Model Context Toolbar The following right mouse button context menu options are available for this object. • Renumber Mesh

Object Properties The Details view properties for this object include the following. Category Definition

Properties Node Offset Element Offset Suppressed: suppressing this object returns the mesh numbering to their original values. Compress Numbers

Modal Defines the modal analysis whose mode shapes are to be used in a random vibration, response spectrum, or harmonic (MSUP) linked analysis (not shown below).

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Objects Reference Tree Dependencies: • Valid Parent Tree Object: Random Vibration, Response Spectrum, or Harmonic Response (linked) environment object. • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: Appears by default for a random vibration analysis, response spectrum analysis, or harmonic (MSUP) linked analysis. Additional Related Information: • Random Vibration Analysis (p. 202) • Response Spectrum Analysis (p. 207) • Harmonic Response Analysis Using Linked Modal Analysis System (p. 189)

Object Properties The Details view properties for this object include the following. Category Definition

Fields Modal Environment

Model Defines the geometry for the particular branch of the tree. The sub-levels provide additional information about the Model object, including loads, supports and results, but do not replace the geometry. 1366

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Named Selections Graphic settings applied to the Model object apply to lower level objects in the tree. The Model object groups geometry, material assignments, connections, and mesh settings. The Geometry, Connections and Mesh objects are not created until geometry is successfully attached. Tree Dependencies: • Valid Parent Tree Object: Project • Valid Child Tree Objects: Chart, Comment, Connections, Coordinate Systems, environments, Figure, Geometry, Image, Mesh, Named Selection, Solution Combination, Symmetry, Virtual Topology Insertion Options: Appears by default for attached geometry. Additional Related Information: • Attaching Geometry • Model Context Toolbar The following right mouse button context menu options are available for this object. • Solve • Disable Filter/Auto Filter • Clear Generated Data

Object Properties The Details view properties for this object include the following. Category

Fields

Filter Options

Control

Lighting

Ambient Light Diffuse Light Specular Light Light Color

Named Selections Named Selections is a folder object that includes any number of individual user-defined Selection objects.

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Objects Reference Tree Dependencies: • Valid Parent Tree Object: Model • Valid Child Tree Objects: Individual named selection objects, Comment, Figure, Image

Note Comment, Figure, and Image are also child objects of individual named selection objects.

Insertion Options: Use any of the following methods: • Click Named Selection button on the Model Context Toolbar (p. 55). • Select geometry items for grouping in the Geometry window, or select Body objects in the tree, then choose Create Named Selection (left button on the Named Selection Toolbar or right-click context menu choice). • Import named selections from a CAD system or from DesignModeler. • Automatically inserted in the event of a mesher failure so that problem surface bodies can be identified. Additional Related Information: • Named Selections • Named Selection Toolbar • Geometry Preferences • Named Selection (DesignModeler Help) • Enclosure (DesignModeler Help) The right mouse button context menu option Generate Named Selections is available from the Named Selections object. This option updates all named selection child objects that were specified using the Worksheet. It is a substitute for the Worksheet Generate button to ensure that all worksheet-based named selection updates are captured. The following right mouse button context menu options are available for child objects of a Named Selections object.

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Named Selections • Select Items in Group • Add to Current Selection • Remove from Current Selection • Create Nodal Named Selection

Object Properties The Details view properties for this object include the following. The following applies only to the Named Selections object folder: Category

Fields/Descriptions

Display

Show Annotation

Worksheet Based Named Selections

Generate on Refresh — Updates Named Selection criteria automatically following a geometry update. Generate on Remesh — Updates the Node ids and locations based on the new mesh.

The following applies only to the child objects of a Named Selections object folder: Category

Fields/Descriptions

Scope

Geometry Selection Worksheet

Definition

Send to Solver controls whether the named selection is passed to the solver. Also see Passing Named Selections to the Solver in the Meshing help.

Note The solvers supported by Mechanical are the only solvers that recognize node- and element-based Named Selections. Therefore, the Send to Solver feature supports Mechanical solvers only for nodeand element-based Named Selections. Visible — displays named selection when set to Yes. Program Controlled Inflation (Include/Exclude) determines whether faces in the named selection are selected to be inflation boundaries for Program Controlled inflation. Also see Program Controlled inflation in the Meshing help. Statistics Read-only status indications

Type — Manual if named selection was created in the Mechanical application or generated due to a mesher failure; Imported if named selection was imported. Total Selection Suppressed Hidden

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Objects Reference Category

Fields/Descriptions Used by Mesh Worksheet — Yes if named selection is being used by the Mesh worksheet. Also see the description of the Mesh worksheet in the Meshing help. Tolerance Type

Tolerance

• Program Controlled — Assigns default values. • Manual — Makes Zero Tolerance and Relative Tolerance available. Zero Tolerance Relative Tolerance — Multiplying factor applied to the values in the entire Worksheet.

Numbering Control Represents a part, vertex, or Remote Point whose nodes/elements can be renumbered. Any number of these objects can exist within a Mesh Numbering folder. Tree Dependencies: • Valid Parent Tree Object: Mesh Numbering • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: Use any of the following methods after selecting Mesh Numbering object: • Click Numbering Control button on Mesh Numbering context toolbar. • Click right mouse button on Mesh Numbering object or in the Geometry window> Insert> Numbering Control. Additional Related Information: • Mesh Numbering • Model Context Toolbar The following right mouse button context menu options are available for this object. • Renumber Mesh

Object Properties The Details view properties for this object include the following.

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Part Category

Fields

Scope

Scoping Method — specify either Geometry Selection or Remote Point. Geometry — appears if Scoping Method is set to Geometry Selection. Remote Points — appears if Scoping Method is set to Remote Point.

Definition

Begin Node Number — appears if Geometry is set to a part. End Node Number — appears if Geometry is set to a part. Begin Element Number — appears if Geometry is set to a part. End Element Number — appears if Geometry is set to a part. Node Number — appears if Geometry is set to a vertex or if Remote Points is set to a specific Remote Point. Suppressed

Part Defines a component of the attached geometry included under a Geometry object. The Part object is assumed to be a multibody part with Body objects beneath it as depicted in the figure below. The Part object label in your Project tree inherits the name from the CAD application you use to create the part and may differ based on the CAD application. Refer to the Body objects reference page if the Geometry object does not include a multibody part, but instead only includes individual bodies. Also see the description of the Virtual Body Group (p. 1407) object (applicable to assembly meshing algorithms only). Tree Dependencies: • Valid Parent Tree Object: Geometry • Valid Child Tree Objects: Body, Comment, Figure, Image Insertion Options: Appears by default when geometry is attached that includes a multibody part. Additional Related Information: • Attaching Geometry The following right mouse button context menu options are available for this object. • Search Faces with Multiple Thicknesses • Create Selection Group • Generate Mesh • Preview> Surface Mesh — appears only for a solid body. • Preview> Inflation

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Objects Reference

Object Properties The Details view properties for this object include the following. Category

Fields

Graphics Properties

Visible — Turns part display On or Off in the Geometry window.

Definition

Suppressed Assignment Brick Integration Scheme — appears only if Element Control is set to Manual in the Details view of the Geometry object. Coordinate System — Assign a local coordinate system to specify the alignment of the elements of the part if previously defined using one or more Coordinate System objects; not available if Stiffness Behavior is set to Rigid.

Bounding Box

Length X Length Y Length Z

Properties — Readonly indication of the properties originally assigned to the part.

Volume Mass — Appears only in the Mechanical application.

Note If the material density is temperature dependent, the Mass will be computed at the body temperature, or at 22oC (default temperature for an environment). Centroid X Centroid Y Centroid Z Moment of Inertia Ip1 Moment of Inertia Ip2 Moment of Inertia Ip3 Surface Areas (approx.)

Statistics — Readonly indication of the entities that comprise the part.

Nodes Elements Mesh Metric

Path Represents a spatial curve to which you can scope results. The results are evaluated at discrete points along this curve.

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Periodic/Cyclic Region Tree Dependencies: • Valid Parent Tree Object: Construction Geometry • Valid Child Tree Objects: Comment, Figure, Image. Insertion Options: Use any of the following methods after selecting Construction Geometry object: • Click Path button on Construction Geometry context toolbar. • Click right mouse button on Construction Geometry object or in the Geometry window> Insert>Path. Additional Related Information: • Path (Construction Geometry) (p. 453) • Construction Geometry (p. 1313) object reference The following right mouse button context menu options are available for this object. • Snap to mesh nodes • Export

Object Properties The Details view properties for this object include the following. Category

Fields

Definition

Path Type Path Coordinate System Number of Sampling Points Suppressed Show Mesh

Start

Coordinate System Start X Coordinate Start Y Coordinate Start Z Coordinate Location

End

Coordinate System End X Coordinate End Y Coordinate End Z Coordinate Location

Periodic/Cyclic Region Defines an individual plane for periodic conditions, anti-periodic conditions, or cyclic conditions. The collection of all Periodic/Cyclic Region objects exists under one Symmetry object.

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Objects Reference Tree Dependencies: • Valid Parent Tree Object: Symmetry • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: Use any of the following methods after highlighting Symmetry object: • Choose Periodic/Cyclic Region on Symmetry context toolbar. • Click right mouse button on Symmetry object, on an existing Periodic/Cyclic Region or Symmetry Region object, or in the Geometry window> Insert> Periodic/Cyclic Region. Additional Related Information: • Symmetry • Symmetry in the Mechanical Application • Symmetry Context Toolbar

The following right mouse button context menu option is available for this object. • Flip High/Low

Object Properties The Details view properties for this object include the following. Category

Fields

Scope

Scoping Method Low Boundary — appears if Scoping Method is set to Geometry Selection. High Boundary — appears if Scoping Method is set to Geometry Selection. Low Selection — appears if Scoping Method is set to Named Selection. High Selection — appears if Scoping Method is set to Named Selection.

Definition

Scope Mode Type — appears for Periodic Region only. Coordinate System

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Point Mass Suppressed

Point Mass Represents the inertial effects from a body. Tree Dependencies: • Valid Parent Tree Object: Geometry • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: Use any of the following methods after highlighting Geometry object or Body object: • Click Point Mass button on Geometry context toolbar. • Click right mouse button on Geometry object, Body object, or in the Geometry window> Insert> Point Mass. Additional Related Information: • Point Mass Application • Coordinate Systems • Geometry Context Toolbar The following right mouse button context menu options are available for this object. • Promote Remote Point (Remote Attachment Only)

Object Properties The Details view properties for this object include the following. Category Scope

Fields Scoping method — Specify as Geometry Selection (default) or Named Selection or Remote Point (only available when a userdefined Remote Point exists in the tree). Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools. Use selection filters to pick geometry, click in the Geometry field, then click Apply. The Remote Attachment option is the required Applied By property (see below) setting if the geometry scoping is to a single face or multiple faces, a single edge or multiple edges, or multiple vertices.

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Objects Reference Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections. Remote Points — Visible when the Scoping Method is set to Remote Point. This field provides a drop-down list of available user–defined Remote Point. Applied By — Specify as Remote Attachment (default) or Direct Attachment. Coordinate System — Assign load to a local coordinate system if previously defined using one or more Coordinate System objects. The Point Mass will automatically be rotated into the selected coordinate system if that coordinate system differs from the global coordinate system. X Coordinate — Define X coordinate location; can be designated as a parameter. Y Coordinate — Define Y coordinate location; can be designated as a parameter. Z Coordinate — Define Z coordinate location; can be designated as a parameter. Location — Change location of the load. Pick new location, click in the Location field, then click Apply. Mass — Define mass; can be designated as a parameter. Mass Moment of Inertia X — Available for 3D models only. Mass Moment of Inertia Y — Available for 3D models only. Mass Moment of Inertia Z — Available for 2D and 3D models. Suppressed Behavior Pinball Region

Definition

Pre-Meshed Crack Defines a crack that is based on a previously generated mesh and used to analyze crack fronts based on a Named Selection. Tree Dependencies: • Valid Parent Tree Object: Fracture Insertion Options: Click right mouse button on Fracture, Crack, or Pre-Meshed Crack object and select Insert> Pre-Meshed Crack. Additional Related Information: • Defining a Pre-Meshed Crack (p. 473)

The following right mouse button context menu options are available for this object. • Insert>Crack • Insert>Pre-Meshed Crack

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Pre-Stress • Suppress

Object Properties The Details view properties for this object include the following. Category

Fields

Scope

Source — Read-only field indicating the type of crack definition. Scoping Method — Read-only and always set to Named Selection when defining pre-meshed cracks. Crack Tip (Nodal Named Selection) — Assign the scoping of the PreMeshed Crack to a valid Named Selection. Click in the Named Selection field and select a named selection consisting of nodes. This option is only applicable to 2D analysis. Crack Front (Named Selection) — Assign the scoping of the Pre-Meshed Crack to a valid Named Selection. Click in the Named Selection field and select a named selection consisting of nodes. This option is only applicable to 3D analysis.

Definition

Coordinate System — Specifies the coordinate system that defines the position and orientation of the crack. The Y axis of the specified coordinate system defines the crack surface normal. The origin of the coordinate system represents the open side of the crack. You can select the default coordinate system or a local coordinate system that you have defined. The default is the Global Coordinate System. The valid coordinate system must be of type Cartesian. Solution Contours — Specifies the number of contours for which you want to compute the fracture result parameters. Suppressed — Toggles suppression of the Pre-Meshed Crack object. The default is No. The Pre-Meshed Crack object is suppressed automatically if the scoped named selection is suppressed.

Pre-Stress Defines the structural analysis whose stress results are to be used in a Harmonic Response Analysis or Modal Analysis, or whose stress-stiffening effects are to be used in a Linear Buckling Analysis, or whose stresses, strains, and/or displacements, or velocities are to be used in an Explicit Dynamics Analysis. Tree Dependencies: • Valid Parent Tree Object: Harmonic Response, Modal, or Linear Buckling , or Explicit Dynamics environment object. • Valid Child Tree Objects: Commands, Comment, Figure, Image Insertion Options: Appears by default for a Harmonic Response, Modal, Linear Buckling, or an Explicit Dynamics analysis.

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Objects Reference

Additional Related Information: • Harmonic Response • Modal Analysis (p. 196) • Linear Buckling Analysis (p. 192) • Explicit Dynamics Analysis (p. 155) • Define Initial Conditions

Object Properties The Details view properties for this object include the following. Category

Fields

Definition

Pre-Stress Environment Harmonic Response, Modal, or Linear Buckling environments only: Pre-Stress Define By — Specify this property as Program Controlled (default), Load Step, or Time. Pre-Stress Loadstep — Displays when Pre-Stress Define By is specified as Load Step. Enter the load step of Static Structural analysis that you’ll use as the starting point to begin your Harmonic Response, Modal, or Linear Buckling analysis. The default value is Last.

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Probe Pre-Stress Time — Displays when Pre-Stress Define By is specified as Time. Enter the time from the Static Structural analysis that you want to use as the starting point to begin your Harmonic Response, Modal, or Linear Buckling analysis. The default value is End Time. Reported Loadstep — Read-only field. Reported Substep — Read-only field. Reported Time — Read-only field. Contact Status — Options include Use True Status, Force Sticking, Force Bonded. Newton-Raphson Option — Read-only field for Pre-Stressed Modal Analyses. Indicates whether the property was selected in the prestressed environment. Options include Program Controlled, Full, Modified, Unsymmetric. Explicit Dynamics environments only: Mode — Specify this property as Displacement or Material State. Time Step Factor — Displays when Mode is specified as Displacement. Pressure Initialization — Displays when Mode is specified as Material State. Specify this property as From Deformed State (default) or From Stress Trace. Time — The time at which results are extracted from the implicit analysis.

Probe Determines results at a point on a model or finds minimum or maximum results on a body, face, vertex, or edge. Tree Dependencies: • Valid Parent Tree Object: Solution • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: • Use any of the following methods after highlighting Solution object or an existing Probe object: – Choose Probe> {specific probe} on Solution context toolbar. – Click right mouse button on Solution object or in the Geometry window> Insert> Probe> {specific probe}. Additional Related Information: • Probes (p. 1001)

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Objects Reference The following right mouse button context menu options are available for this object: • Evaluate All Results • Rename Based on Definition

Object Properties See the Probe Details View (p. 1003) section.

Project Includes all objects in the Mechanical application and represents the highest level in the object tree. Only one Project can exist per Mechanical session. Tree Dependencies: • Valid Parent Tree Object: None — highest level in the tree. • Valid Child Tree Objects: Comment, Model Insertion Options: Appears by default in every Mechanical session. The following right mouse button context menu options are available for this object. • Solve • Export — this option provides two selections: – Geometry — exports a CAD file in Mechanical’s native format, corresponding to a binary Part Manager Database of PMDB. – Mesh — following mesh generation, exports the mesh, including nodes, elements, and applicable topology references, in an ACMO binary database format. • Clear Generated Data

Object Properties The Details view properties for this object include the following. Category

Fields

Title Page — You can enter the following information that will appear on the title page of the report.

Author Subject Prepared for

Information — The Mechanical application

First Saved Last Saved

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Remote Point provides the following information that will appear on the title page of the report. Project data Management

Product Version

Save Project Before Solution- Saves the entire project immediately before solving (after any required meshing). If the project had never been previously saved, you can now select a location to save a new file. Save Project After Solution- Saves the project immediately after solving but before postprocessing. If the project had never been previously saved, nothing will be saved.

Note • The default values can be specified in Tools>Options under the Miscellaneous section. • The Save Options defaults are applicable only to new projects. These settings will not be changed for existing projects. • These properties are not supported if you are using the Workbench System Coupling component system in combination with your Mechanical analysis.

Remote Point Allows scoping of remote boundary conditions. Tree Dependencies: • Valid Parent Tree Object: Remote Points. • Valid Child Tree Objects: Commands, Comment, Figure Insertion Options: Use any of the following methods after highlighting Model or Remote Points object: • Choose Remote Point on Model or Remote Points context toolbar. • Click right mouse button on the Model or Remote Points object or in the Geometry window and select Insert> Remote Point. Additional Related Information: • Remote Point

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Objects Reference • Remote Boundary Conditions The right mouse button context menu option Promote to Named Selection is available for Remote Point objects. The Details view properties for this object include the following. Category

Fields

Scope

Scoping Method — Specify as Geometry Selection (default) or Named Selection. Geometry — appears if Scoping Method is set to Geometry Selection. Choose geometry entity then click on Apply. Named Selection — appears if Scoping Method is set to Named Selection. Choose a Named Selection from the drop-down menu. Named selections can be geometry or node-based. Coordinate System — the Coordinate System based on the original location of the remote point. This property does not change if you modify the remote point’s position with the Location property. X Coordinate — the distance from the coordinate system origin on the x axis. Y Coordinate — the distance from the coordinate system origin on the y axis. Z Coordinate — the distance from the coordinate system origin on the z axis. Location — the location in space of the remote point. This property allows you to manually modify the remote point’s original position. Changing the Location does not establish a new coordinate system (reflected by the above Coordinate System property) and replots the x, y, and z coordinate locations.

Definition

Suppressed Behavior Pinball Region DOF Selection – specify as Program Controlled (default) or Manual. This property provides control of which DOF’s will activate for corresponding constraint equations. If the Manual setting is selected, the following additional properties display. • X Component • Y Component • Z Component • Rotation X • Rotation Y

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Result Tracker Category

Fields • Rotation Z

Remote Points Houses all Remote Point objects. Tree Dependencies: • Valid Parent Tree Object: Model • Valid Child Tree Objects: Comment Remote Point Insertion Options: Use any of the following methods after highlighting Model object: • Choose Remote Point on Model context toolbar. • Click right mouse button on the Model object or in the Geometry window, select Insert> Remote Point. Additional Related Information: • Remote Point • Remote Boundary Conditions

Object Property The Details view property for this object includes the following. Category Graphics

Fields Show Connection Lines

Result Tracker Provides results graphs of various quantities (for example, deformation, contact, temperature, kinetic energy, stiffness energy) vs. time. Tree Dependencies: • Valid Parent Tree Object: Solution Information • Valid Child Tree Objects: Comment, Image Insertion Options: Use any of the following methods after highlighting Solution Information object:

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Objects Reference • Choose Result Tracker> {name of Result Tracker} on Solution Information context toolbar.

Note You will not be able to add a Result Tracker from the Solution Information context toolbar if the solution is in a solved state. You will need to clear the solution before adding a Result Tracker.

• Click right mouse button on Solution Information object or in the Geometry window> Insert> {name of Result Tracker}. Additional Related Information: • Result Tracker Objects • Solution Context Toolbar The following right mouse button context menu options are available for this object. • Export — available after solution is obtained. • Rename Based on Definition

Object Properties The Details view properties for this object include the following.

Note Properties may differ for Result Trackers in Explicit Dynamics systems. See Explicit Dynamics Result Trackers (p. 1054) for more information. Category

Fields

Definition

Type — Read-only indication of result tracker type for Deformation and Temperature objects. For Contact object, specify contact output. Orientation — appears for a Deformation result tracker object. Suppression – Prior to solving, you can include or exclude the result from the analysis. The default is value is No.

Scope

Scoping Method — appears for a Temperature result tracker object.

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Results and Result Tools (Group) Geometry — appears for a Deformation result tracker object, or for a Temperature object if Scoping Method is set to Geometry Selection. Use selection filters to pick geometry, click in the Geometry field, then click Apply. Contact Region — appears for a Contact result tracker (p. 1052) object. Results

Minimum — Read-only indication of the minimum value of the result tracker type. Maximum — Read-only indication of the maximum value of the result tracker type.

Filter — displayed only for Explicit Dynamics systems.

Type Cut Frequency — appears if Type = Butterworth. Minimum filtered value — appears if Type = Butterworth. Maximum filtered value — appears if Type = Butterworth.

Results and Result Tools (Group) Defines the engineering output for displaying and analyzing the results from a solution. Applies to the following objects: Category

Object

Structural

Bending Stress, Campbell Diagram, Directional Acceleration, Damage Status, Directional Deformation, Directional Velocity, Elastic Strain Intensity, Energy Dissipated Per Unit Volume, Equivalent Creep Strain, Equivalent Plastic Strain, Equivalent Stress, Equivalent Total Strain, Fiber Compressive Damage Variable, Fiber Compressive Failure Criterion, Fiber Tensile Damage Variable, Fiber Tensile Failure Criterion, Frequency Response, Linearized Stresses, Max Failure Criteria, Matrix Compressive Damage Variable, Matrix Compressive Failure Criterion, Matrix Tensile Damage Variable, Matrix Tensile Failure Criterion, Maximum Principal Elastic Strain, Maximum Principal Stress, Maximum Shear Elastic Strain, Maximum Shear Stress, Membrane Stress, Middle Principal Elastic Strain, Middle Principal Stress, Minimum Principal Elastic Strain, Minimum Principal Stress, Mullins Damage Variable, Mullins Max Previous Strain Energy, Normal Elastic Strain, Normal Gasket Pressure, Normal Gasket Total Closure, Normal Stress, Phase Response, Sheer Damage Variable, Shear Elastic Strain, Shear Gasket Pressure, Shear Gasket Total Closure, Shear Stress, Strain Energy, Stress Intensity, Structural Error, Thermal Strain, Total Acceleration, Total Deformation, Total Velocity, Vector Principal Elastic Strain, Vector Principal Stress

Structural Beams

Axial Force, Beam Tool, Bending Moment, Direct Stress, Maximum Bending Stress, Maximum Combined Stress, Minimum Bending Stress, Minimum Combined Stress, Shear Force, ShearMoment Diagram, Torsional Moment

Thermal Directional Heat Flux, Temperature, Thermal Error, Total Heat Flux Magnetostatic

Current Density, Directional Field Intensity, Directional Flux Density, Directional Force, Electric Potential, Flux Linkage, Inductance, Magnetic Error, Total Field Intensity, Total Flux Density, Total Force

Electric

Directional Current Density, Directional Electric Field Intensity, Electric Voltage, Joule Heat, Total Current Density, Total Electric Field Intensity

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Objects Reference Category General

Object Coordinate Systems Results (group), User Defined Result

Tree Dependencies: • Valid Parent Tree Object: – For Direct Stress, Maximum Bending Stress, Maximum Combined Stress, Minimum Bending Stress, Minimum Combined Stress: Beam Tool – For Directional Deformation, Total Deformation: Beam Tool, Solution – For all other result objects: Solution • Valid Child Tree Objects: – For Beam Tool: Comment, Direct Stress, Directional Deformation, Figure, Image, Maximum Bending Stress, Maximum Combined Stress, Minimum Bending Stress, Minimum Combined Stress, Total Deformation – For all other objects: Comment, Figure, Image

Note Alert and Convergence may also apply.

Insertion Options: • For results and result tools that are direct child objects of a Solution object, use any of the following methods after highlighting the Solution object: – Open one of the toolbar drop-down menus or result category on the Solution context toolbar. – Right-click the mouse on Solution object or in the Geometry window, and the select Insert and then the desired result or result category. • For results that are direct child objects of a specific result tool, use any of the following methods after highlighting the specific result tool object: – Choose result on the context toolbar related to the result tool. – Right-click the mouse on a specific result tool object Insert and then the desired result or result category. Additional Related Information: • «Using Results» (p. 857) • Solution Context Toolbar

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Results and Result Tools (Group) • Layered and Surface Body Results (p. 875) The following right mouse button context menu options may be available based on the Result object. • Export • Evaluate All Results • Convert To Path Result (for Results scoped to Edges Only) • Promote to Named Selection • Rename Based on Definition

Object Properties The Details view properties for this object may include the following. The following applies to many result objects whose direct parent object is Solution. Many exceptions are noted. For more complete information check individual descriptions for all results and result tools. Category

Fields

Scope

Scoping Method — Geometry Selection, Named Selection, Path, or Surface. Geometry — appears if Scoping Method = Geometry. Use selection filters to pick geometry, click in the Geometry field, then click Apply. Named Selection — appears if Scoping Method = Named Selection. Specify named selection. Path — appears if Scoping Method = Path. Select defined path. Surface — appears if Scoping Method = Surface. Select defined surface. Shell — appears only for stress and strain results scoped to a surface body. Layer — Specifies the layer to calculate Shell result values.

Definition

Type — result type indication, can be changed within the same result category. Read-only indication for: Current Density, Electric Potential, Equivalent Plastic Strain, Strain Energy, Magnetic Error, Structural Error, Temperature, Thermal Error, User Defined Result, Vector Principal Elastic Strain, Vector Principal Stress, J-Integral, VCCT, SIFS Orientation — appears only for: Axial Force, Directional Deformation, Directional Field Intensity, Directional Flux Density, Directional Force, Directional Heat Flux, Normal Elastic Strain, Normal Stress, Shear Elastic Strain, Shear Stress, Torsional Moment, Shell Membrane Stress, Shell Bending Stress. Expression — appears only for User Defined Result. Input Unit System — appears only for User Defined Result. Output Unit — appears only for User Defined Result. Identifier — appears only for User Defined Result. Coordinate System — only displayed for results that change with respect to a coordinate system, such as Normal Stress. For these result types you can specify: default Global Coordinate System, local Coordinate System, or Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Objects Reference Solution Coordinate System (for most element types the Solution Coordinate System aligns with the global coordinate system, however, for surface and line bodies, elements may align themselves on a per element basis and therefore create random alignments. To correct this, specify a local coordinate system on each part and choose Solution Coordinate System option to ensure that the displayed elements have a consistent alignment). By — Maximum Over “…” is the maximum result over an independent variable for the node, element, or sample point. “…” of Maximum is the value of the independent variable that the maximum occurred for the node, element, or sample point. Neither option is available for non-cyclic modal results, or linearized stress results. Display Time — appears if By is set to Time. (See Note below.) Frequency — appears if By is set to Frequency. (See Note below.) Set Number — appears if By is set to Set. Mode — appears for Modal analyses. Calculate Time History — appears if By is set to Time or Set. Sweeping Phase — appears if By is set to Frequency, Set (Harmonic Response analyses), Mode (Damped Modal Analyses), Maximum Over Frequency, or Frequency of Maximum. Phase Increment — appears if By is set to Maximum Over Phase or Phase of Maximum. The entry can be between 1o and 10o. The default value is 1o. Identifier — appears only for User Defined Result. Suppressed — suppresses the object if set to Yes. Contour Start — appears only for Fracture Results. Contour End — appears only for Fracture Results. Active Contour — appears only for Fracture Results.

Note If you specify a Display Time or Frequency value which exceeds the final time or frequency in the result file, then Mechanical will not allow the result to be evaluated. If you specify a Display Time or Frequency value for which no results are available, then Mechanical performs a linear interpolation to calculate the results at that specified time. The two times or frequencies in the result file that are the closest to the specified time/frequency are used in the interpolation. No interpolation is performed for the Fracture Tool results. That is, for Fracture Results with a Display Time between the two solution time points, only the data set associated with the lower of the solution time points is used. Integration Point Results

Display Option — appears only for result items that can display unaveraged contour results. Average Across Bodies — When you select Averaged as the Display Option, this property displays. Setting this property to Yes (the default value is No) averages results across separate bodies.

Results — Readonly status indication of result object.

Minimum — not available for Vector Principal Stress. Maximum — not available for Vector Principal Stress. Minimum Occurs On — not available for: Current Density, Electric Potential, Strain Energy, Vector Principal Stress.

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Solution Maximum Occurs On — not available for: Current Density, Electric Potential, Strain Energy, Vector Principal Stress. Maximum Value Over Time

This category provides read-only properties that display maximum values of the results you select over time. These properties are only applicable for static, transient, explicit, and design assessment analyses.

Minimum Value Over Time

This category provides read-only properties that display minimum values of the results you select over time. These properties are only applicable for static, transient, explicit, and design assessment analyses.

Information Read-only status indication of time stepping.

Time Load Step Substep Iteration Number

Note If a result changes with respect to coordinate systems, then Mechanical rotates this result in an identical fashion to MAPDL. For an explanation of rotating results to a different coordinate system, see Additional POST1 Postprocessing in the Basic Analysis Guide.

Solution Defines result types and formats for viewing a solution. Tree Dependencies: • Valid Parent Tree Object: Any environment object. • Valid Child Tree Objects: All general Results and Result Tools, Commands, Comment, Figure, Image, Solution Information Insertion Options: Appears by default for any analysis.

Note A Solution object cannot be deleted from the tree. Additional Related Information: • «Understanding Solving» (p. 1023) • Solution Context Toolbar • Adaptive Convergence The following right mouse button context menu options are available for this object. • Evaluate All Results • Stop Solution: available only for RSM solutions. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Objects Reference • Interrupt Solution: available only for RSM solutions. • Clear Generated Data • Open Solver Files Directory: available for Windows OS only. • Worksheet: Result Summary: available following the completion of the solution process. This option displays the results content in a tabular format.

Object Properties The Details view properties for this object include the following. Category

Fields

Adaptive Mesh Refinement

Max Refinement Loops Refinement Depth

Refinement Controls appears only for magnetostatic analyses if a Convergence object is inserted under a result.

Element Selection Energy Based — appears if Element Selection is set to Manual. Error Based — appears if Element Selection is set to Manual.

Solution Combination Manages solutions that are derived from the results of one or more environments. See Design Assessment for additional Solution Combination capabilities. Tree Dependencies: • Valid Parent Tree Object: Model • Valid Child Tree Objects: all stress and strain result objects, Directional Deformation, Total Deformation, Contact Tool (only for Frictional Stress, Penetration, Pressure, and Sliding Distance), Fatigue Tool , Stress Tool, Comment, Image Insertion Options: Use any of the following methods after highlighting Model object: • Choose Solution Combination on Model context toolbar. • Click right mouse button on Model object or in the Geometry window> Insert> Solution Combination. Additional Related Information: • Solution Combinations • Underdefined Solution Combinations (Troubleshooting) The Evaluate All Results right mouse button context menu option is available for this object.

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Spot Weld

Solution Information Allows tracking, monitoring, or diagnosing of problems that arise during a nonlinear solution. Also allows viewing certain finite element aspects of the engineering model. Tree Dependencies: • Valid Parent Tree Object: Connections, Solution • Valid Child Tree Objects: Comment, Image, Result Tracker (available only when Solution is the parent) Insertion Options:: • Automatically inserted under a Solution object of a new environment or of an environment included in a database from a previous release. • Click right mouse button on Connections object or in the Geometry window> Insert> Solution Information. Additional Related Information: • Solution Information The following right mouse button context menu option is available for this object. • Export FE Connections

Object Properties The Details view properties for this object include the following. Category

Fields

Solution Information

Solution Output — not applicable to Connections object. Newton-Raphson Residuals — applicable only to Structural environments. Update Interval — appears for synchronous solutions only Display Points — not applicable to Connections object. Display Filter During Solve — appears for Explicit Dynamics systems only.

FE Connection Visibility

Activate Visibility Display Line Color Color — appears if Line Color is set to Manual. Visible on Results Line Thickness

Spot Weld Defines conditions for individual contact and target pairs for a spot weld, which is used to connect individual surface body parts to form a surface body model assembly , just as a Contact Region object

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Objects Reference is used to form a solid model assembly. Several Spot Weld objects can appear as child objects under a Connection Group object. The Connection Group object name automatically changes to Contacts. Tree Dependencies: • Valid Parent Tree Object: Connections • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: Use any of the following methods after highlighting Connections object: • Inserted automatically if spot welds are defined in the CAD model and you choose Create Automatic Connections through a right mouse click on Connections (or Contacts) object. • Click Spot Weld button on Connections context toolbar. • Click right mouse button on Connections (or Connection Group) object or in the Geometry window > Insert> Spot Weld. Additional Related Information: • Spot Welds • Connections Context Toolbar The following right mouse button context menu options are available for this object. • Enable/Disable Transparency • Hide All Other Bodies • Flip Contact/Target • Merge Selected Contact Regions — appears if contact regions share the same geometry type. • Save Contact Region Settings • Load Contact Region Settings • Reset to Default • Rename Based on Definition

Object Properties The Details view properties for this object include the following.

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Spring Category

Fields

Scope

Scoping Method Contact (p. 507) Target (p. 508) Contact Bodies (p. 508) Target Bodies (p. 508)

Definition

Scope Mode ed

Spring An elastic element that regains its undeformed shape after a compression or extension load is removed. Tree Dependencies: • Valid Parent Tree Object: Connections • Valid Child Tree Objects: Commands, Comment, Figure, Image Insertion Options: Use any of the following methods after highlighting Connections object: • Click Body-Ground> Spring or Body-Body> Spring, as applicable on Connections context toolbar. • Click right mouse button on Connections object or in the Geometry window> Insert> Spring. Additional Related Information: • Connections Context Toolbar • Springs (p. 606) The following right mouse button context menu options are available for this object. • Enable/Disable Transparency — similar behavior to feature in Contact Region. • Rename Based on Definition — similar behavior to feature in Contact Region. • Promote to Remote Point (Remote Attachment Only) • Promote to Named Selection

Object Properties The Details view properties for this object include the following. Category

Fields

Graphics Properties

Visible

Definition

Type — read only indication of Longitudinal Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Objects Reference Spring Behavior Longitudinal Stiffness Longitudinal Damping Preload Suppressed Spring Length — read only indication. Scope

Scope — options include Body-Body or Body-Ground.

Reference

Scoping Method — Specify as Geometry Selection, Named Selection, or Remote Point. Applied By — Displays for Body-Body scoping. Specify as Remote Attachment or Direct Attachment. The default for this property can differ if you first select geometry or a mesh node. Scope — appears if Scope (under Scope group) is set to Body-Body and Scoping Method is set to Geometry Selection. Choose geometry entity then click on Apply. Reference Component — appears if Scope (under Scope group) is set to BodyBody and Scoping Method is set to Named Selection. Remote Points- appears if Scope (under Scope group) is set to Body-Body and Scoping Method is set to Remote Point. This property provides a dropdown list of available user-defined Remote Points. This property is not available when the Applied By property is specified as Direct Attachment. Body — Read-only indication of scoped geometry. The following options appear if Scope (under Scope group) is set to BodyGround or if Scope is set to Body-Body and Applied By is specified as Remote Attachment. • Coordinate System • Reference X Coordinate • Reference Y Coordinate • Reference Z Coordinate • Reference Location • Behavior • Pinball Region

Mobile

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Scoping Method — Specify as Geometry Selection or Named Selection. Applied By — Specify as Remote Attachment or Direct Attachment. The default for this property can differ if you first select geometry or a mesh node. Scope — appears if Scoping Method is set to Geometry Selection. Choose geometry entity then click on Apply. Mobile Component — appears if Scoping Method is set to Named Selection. Remote Points- appears if the Scoping Method is set to Remote Point. This property provides a drop-down list of available user-defined Remote Points. This property is not available when the Applied By property is specified as Direct Attachment. Body — Read-only indication of scoped geometry.

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Stress Tool (Group) Body- appears if Scoping Method is set to Geometry Selection. Read-only indication of scoped geometry. The following options appear if Scope (under Scope group) is set to BodyGround and Applied By is specified as Remote Attachment or if Scope is set to Body-Body and Applied By is specified as Remote Attachment. • Coordinate System • Mobile X Coordinate • Mobile Y Coordinate • Mobile Z Coordinate • Mobile Location • Behavior • Pinball Region

Stress Tool (Group) Provides stress safety tools for analyzing simulation results. Applies to the following objects: Safety Factor, Safety Margin, Stress Ratio, Stress Tool Tree Dependencies: • Valid Parent Tree Object: – For Stress Tool: Solution in a static structural or transient structural analysis. – For Safety Factor, Safety Margin, or Stress Ratio: Stress Tool • Valid Child Tree Objects: – For Stress Tool: Comment, Figure, Image, Safety Factor, Safety Margin, Stress Ratio – For Safety Factor, Safety Margin, or Stress Ratio: Alert, Comment, Convergence, Figure, Image Insertion Options: • For Stress Tool, use any of the following methods after highlighting Solution object in a static structural or transient structural analysis: – Choose Tools> Stress Tool on Solution context toolbar. – Click right mouse button on Solution object or in the Geometry window> Insert> Stress Tool> Max Equivalent Stress or Max Shear Stress or MohrCoulomb Stress or Max Tensile Stress.

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Objects Reference • For Safety Factor, Safety Margin, or Stress Ratio, use any of the following methods after highlighting Stress Tool object: – Choose Safety Factor, Safety Margin, or Stress Ratio on Stress Tool context toolbar. – Click right mouse button on Stress Tool object or in the Geometry window> Insert> Stress Tool>Safety Factor, Safety Margin, or Stress Ratio. Additional Related Information: • Stress Tools (p. 904) • Maximum Equivalent Stress Safety Tool (p. 905) • Maximum Shear Stress Safety Tool (p. 907) • Mohr-Coulomb Stress Safety Tool (p. 908) • Maximum Tensile Stress Safety Tool (p. 910) The right mouse button context menu option Evaluate All Results — is available for Safety Factor, Safety Margin, Stress Ratio, and Stress Tool.

Object Properties The Details view properties for this object include the following. For Stress Tool: Category Definition

Fields Theory Factor — appears only if Theory is set to Max Shear Stress. Stress Limit — appears only if Stress Limit Type is set to Custom Value. Stress Limit Type — appears if Theory is set to any stress tool except MohrCoulomb Stress. Tensile Limit — appears only if Theory is set to Mohr-Coulomb Stress and Tensile Limit Type is set to Custom Value. Compressive Limit — appears only if Theory is set to Mohr-Coulomb Stress and Compressive Limit Type is set to Custom Value. Tensile Limit Type — appears only if Theory is set to Mohr-Coulomb Stress. Compressive Limit Type — appears only if Theory is set to Mohr-Coulomb Stress.

For Safety Factor, Safety Margin, or Stress Ratio: Category

Fields

Scope

Scoping Method Geometry — Use selection filters to pick geometry, click in the Geometry field, then click Apply.

Definition

Type – Read-only display of specific stress tool object name. By

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Symmetry Display Time Calculate Time History Use Average Identifier Results — Readonly display of the following values:

Minimum Maximum — appears only for Stress Ratio. Minimum Occurs On Maximum Occurs On — appears only for Stress Ratio.

Information Read-only display of the following values:

Time Load Step Substep Iteration Number

Surface Represents a section plane to which you can scope results. Tree Dependencies: • Valid Parent Tree Object: Construction Geometry • Valid Child Tree Objects: Comment, Figure, Image. Insertion Options: Use any of the following methods after selecting Construction Geometry object: • Click Surface button on Construction Geometry context toolbar. • Click right mouse button on Construction Geometry object or in the Geometry window> Insert> Surface. Additional Related Information: • Surface (Construction Geometry) (p. 459) • Construction Geometry (p. 1313) object reference

Object Properties The Details view properties for this object include the following. Category Definition

Fields Coordinate System Suppressed

Symmetry Represents all definitions of symmetry or periodic/cyclic planes within a model. Each symmetry definition is represented in a Symmetry Region object, each periodic definition is represented in a Periodic Region object, and each cyclic definition is represented in a Cyclic Region object.

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Objects Reference Tree Dependencies: • Valid Parent Tree Object: Model • Valid Child Tree Objects: Comment, Figure, Image, Periodic/Cyclic Region, Symmetry Region Insertion Options: • Automatically inserted in the tree if model includes symmetry planes defined in DesignModeler (using the Symmetry or Enclosure feature). • For manual insertion, use any of the following methods after highlighting Model object: – Choose Symmetry on Model context toolbar. – Click right mouse button on Model object or in the Geometry window> Insert> Symmetry.

Note Only one Symmetry object is valid per Model. Additional Related Information: • Symmetry • Symmetry Context Toolbar

Symmetry Region Defines an individual plane for symmetry or anti-symmetry conditions. The collection of all Symmetry Region objects exists under one Symmetry object. Tree Dependencies: • Valid Parent Tree Object: Symmetry • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: • Automatically inserted in the tree if model includes symmetry planes defined in DesignModeler (using the Symmetry or Enclosure feature). • For manual insertion, use any of the following methods after highlighting Symmetry object: – Choose Symmetry Region on Symmetry context toolbar.

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Thermal Point Mass – Click right mouse button on Symmetry object, on an existing Symmetry Region, Periodic Region, or Cyclic Region object, or in the Geometry window > Insert> Symmetry Region. Additional Related Information: • Symmetry • Symmetry Context Toolbar

Object Properties The Details view properties for this object include the following. Category

Fields

Scope

Scoping Method Geometry — appears if Scoping Method is set to Geometry Selection. Named Selection — appears if Scoping Method is set to Named Selection.

Definition

Scope Mode Type Coordinate System Symmetry Normal Suppress

Thermal Point Mass Represents heat from surrounding objects. Tree Dependencies: • Valid Parent Tree Object: Geometry • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: Use any of the following methods after highlighting Geometry object or Body object: • Click Thermal Point Mass button on Geometry context toolbar. • Click right mouse button on Geometry object, Body object, or in the Geometry window> Insert> Thermal Point Mass. Additional Related Information: • Thermal Point Mass • Coordinate Systems • Geometry Context Toolbar The following right mouse button context menu options are available for this object. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Objects Reference • Promote Remote Point (Remote Attachment Only)

Object Properties The Details view properties for this object include the following. Category Scope

Fields Scoping method — Specify as Geometry Selection (default) or Named Selection or Remote Point (only available when a userdefined Remote Point exists in the tree). Geometry — Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (face, edge, vertex) and the number of geometric entities (for example: 1 Face, 2 Edges) to which the boundary has been applied using the selection tools. Use selection filters to pick geometry, click in the Geometry field, then click Apply. The Remote Attachment option is the required Applied By property (see below) setting if the geometry scoping is to a single face or multiple faces, a single edge or multiple edges, or multiple vertices. Named Selection — Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user–defined Named Selections. Remote Points — Visible when the Scoping Method is set to Remote Point. This field provides a drop-down list of available user–defined Remote Point. Applied By — Specify as Remote Attachment (default) or Direct Attachment. Coordinate System — this property is available when the Applied By property is set to Remote Attachment. Allows you to assign the Thermal Point Mass to a local coordinate system if previously defined using one or more Coordinate System objects. The Thermal Point Mass is automatically rotated into the selected coordinate system if that coordinate system differs from the global coordinate system. The individual coordinate properties, X/Y/Z, are available when the Applied By property is set to Remote Attachment. Define coordinate origins directly. These properties can be designated as a parameter. • X Coordinate • Y Coordinate • Z Coordinate Location — this property is available when the Applied By property is set to Remote Attachment. Allows you to change the location of the load. Once relocated, click in the Location field and then click Apply.

Definition

1400

Thermal Capacitance — Can be designated as a parameter. Suppressed Behavior

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Thickness Pinball Region

Thickness Allows you to define variable thickness properties on selected faces of surface bodies. Tree Dependencies: • Valid Parent Tree Object: Geometry • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: Use any of the following methods after highlighting Geometry object or Body object: • Click Thickness button on Geometry context toolbar. • Click right mouse button on Geometry object, Body object, or in the Geometry window> Insert> Thickness. Additional Related Information: • Specifying Surface Body Thickness (p. 380) • Geometry Context Toolbar The following right mouse button context menu options are available for this object. • Search Faces with Multiple Thicknesses • Promote Remote Point

Object Properties The Details view properties for this object include the following. Category

Fields

Scope

Scoping Method Geometry– appears if Scoping Method is set to Geometry Selection. In this case, use selection filters to pick geometry, click in the Geometry field, then click Apply. Named Selection – appears if Scoping Method is set to Named Selection.

Definition

Scope Mode- read-only indication of Manual or Automatic. Suppressed Thickness Offset Type

Tabular Data — appears if Thickness is set to Tabular Data.

Independent Variable Coordinate System

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Objects Reference Function — appears if Thickness is set to a function.

Unit System — read only indication of the active unit system. Angular Measure — read only indication of the angular measure used to evaluate trigonometric functions.

Graph Controls — appears if Thickness is set to a function.

Number of Segments Range Minimum Range Maximum

Note The above description applies to a Thickness object that you manually insert into the tree. When you include thickness associated with a surface body that you import from DesignModeler, an automatically generated Thickness object is added as a child object beneath the associated Surface Body object. Read only object properties in the Scope and Definition categories are available for these automatically generated Thickness objects. Additionally, the right-click context menu item Make Thickness Manual is available for the automatically generated version of the object.

Validation The Validation object enables you to evaluate the quality of mapping across source and target meshes. It provides quantitative measures that help in identifying regions on the target where the mapping failed to provide an accurate estimate of the source data. You can add validation objects under the Imported Load or Imported Thickness objects. Applies to: Validation objects. Tree Dependencies: • Valid Parent Tree Objects: Imported Load or Imported Thickness objects. • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: Use any of the following methods after highlighting the Imported Load or Imported Thickness objects: • Select Validation in the Environment/Geometry Context Toolbar • Click the right-mouse button on the object you highlighted and select Insert > Validation from the context menu. Additional Related Information: • Imported Load • Imported Thickness

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Validation • Mapping Validation in the ANSYS Mechanical User’s Guide Right-mouse Options: • Analyze: Invokes calculation of Validation object. See Mapping Validation in the ANSYS Mechanical User’s Guide. • Export: Exports the data to a text file in tabbed delimited format. See Exporting Data in the ANSYS Mechanical User’s Guide.

Object Properties The Details view properties for this object include the following. Category

Fields

Definition

File Identifier* — Specify the file identifier(s) from parent object. Row -The row of the parent worksheet. Data -The data type for the imported load. Component -The vector component (X, Y, Z). Complex Component -The real/imaginary component for complex loads. Shell Face -Specify the top/bottom for loads applied to shells.

Note * This property is only available when data is imported through the External Data system. Settings

Type — Specify Reverse Validation, Distance Based Average Comparison, Source Value, or Undefined Points. Number of Points — available when Distance Based Average Comparison is selected. Specifies how many points to use in the distance based average mapping calculations. Output Type — Specify either Relative Difference or Absolute Difference. (This is not displayed for the Source Value or Undefined Points types.)

Graphics Controls

Display – Specify either Scaled Spheres, Colored Spheres, Colored Points, Contours, or Isolines (Isolines are only available for Source Value Output Type when element mesh data is provided) Line Thickness – available when Display is set to Isolines. Control the thickness of the isolines by selecting Single, Double, or Triple. Scale – Specify scale multiplier for increasing and decreasing sphere sizes. Not displayed for Colored Points.

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Objects Reference Category

Fields Display Minimum – appears if object state is solved. Graphics display will use this value to show only items above this threshold. Must be greater than the Minimum and less than the Maximum property. (This is not displayed for the Undefined Points type.) Display Maximum – appears if object state is solved. Graphics display will use this value to only show items below this threshold. Must be greater than Minimum and less than Maximum property. (This is not displayed for the Undefined Points type.) Display In Parent – graphics items can be overlaid on parent objects when this item is set to On. Legend Divisions – control how many contour colors to use in displaying graphics data. (This is not displayed for the Undefined Points type.)

Statistics

Minimum –- read-only minimum value for entire mapped points. (This is not displayed for the Undefined Points type.) Maximum – read-only maximum value for entire mapped points. (This is not displayed for the Undefined Points type.) Number Of Items – read-only number of currently displayed items

Velocity Applies velocity as an initial condition for use in a transient structural analysis or an explicit dynamics analysis. Tree Dependencies: • Valid Parent Tree Object: Initial Conditions • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: Use any of the following methods after highlighting Initial Conditions object: • Click Velocity button on Initial Conditions context toolbar. • Click right mouse button on Initial Conditions object or in the Geometry window > Insert> Velocity. Additional Related Information: • Define Initial Conditions • Transient Structural Analysis (p. 285)

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Virtual Body • Explicit Dynamics Analysis

Object Properties The Details view properties for this object include the following. Category

Fields

Scope

Scoping Method Geometry – appears if Scoping Method is set to Geometry Selection. In this case, use selection filters to pick geometry, click the Geometry field, then click Apply. Named Selection – appears if Scoping Method is set to Named Selection.

Definition

Input Type — choose either Angular Velocity or Velocity. Define By Total– magnitude; appears if Define By is set to Vector. Direction- appears if Define By is set to Vector. Coordinate System – available list; appears if Define By is set to Components. X, Y, Z Component – values; appears if Define By is set to Components.

Virtual Body Defines an individual virtual body. Virtual bodies are supported for assembly meshing only.

Note Virtual Body and Fluid Surface objects are fluids concepts, and as such they are not supported by Mechanical solvers. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Objects Reference Tree Dependencies: • Valid Parent Tree Object: Virtual Body Group • Valid Child Tree Objects: Fluid Surface, Comment, Figure, Image Insertion Options: Use either of the following methods after highlighting the Geometry object: • Click right mouse button on the Geometry object and select > Insert> Virtual Body. • Choose Virtual Body on the Geometry context toolbar. Additional Related Information: • Assembly Meshing • Defining Virtual Bodies

Object Properties The Details view properties for this object include the following. Category

Fields

Graphics Properties

Visible — Toggles visibility of the selected virtual body in the Geometry window.

Definition

Suppressed — Toggles suppression of the selected virtual body. Used By Fluid Surface — Defines whether the virtual body is being used by a set of fluid surfaces. If you change the setting from Yes to No, the Fluid Surface object will be hidden. Material Point — Specifies the coordinate system to be used for the selected virtual body. The default is Please Define. The Fluid Surface object and the Virtual Body object will remain underdefined until a material point is specified. You can select the default coordinate system or define a local coordinate system. In either case, the setting will be retained, even if the Used By Fluid Surface setting is changed later.

Material

Fluid/Solid — Read-only and always set to Fluid for virtual bodies.

Statistics

Nodes — Read-only indication of the number of nodes associated with the virtual body when meshed. Elements — Read-only indication of the number of elements associated with the virtual body when meshed. Mesh Metric — Read-only metric data associated with the virtual body when meshed.

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Virtual Cell

Virtual Body Group Represents all definitions of virtual bodies within a model. Each definition is represented in a Virtual Body object. Virtual bodies are supported for assembly meshing only.

Note Virtual Body and Fluid Surface objects are fluids concepts, and as such they are not supported by Mechanical solvers. Tree Dependencies: • Valid Parent Tree Object: Geometry • Valid Child Tree Objects: Virtual Body, Comment, Figure, Image Insertion Options: When you insert the first Virtual Body object into the tree, the Virtual Body Group object is inserted automatically. Additional Related Information: • Assembly Meshing • Defining Virtual Bodies

Object Properties The Details view properties for this object include the following. Category

Fields

Graphics Properties

Visible — Toggles visibility of the virtual body group in the Geometry window

Definition

Suppressed — Toggles suppression of the virtual body group object

Statistics

Nodes — Read-only indication Elements — Read-only indication Mesh Metric — Read-only indication

Virtual Cell Defines an individual face or edge group, defined manually or automatically. Virtual Cell objects do not appear in the tree. Creation Options: • For automatic creation of virtual cell regions, a Virtual Cell object is created for each region that meets the criterion specified in the Details view of the Virtual Topology object.

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Objects Reference • For manual creation of Virtual Cell objects, highlight the Virtual Topology object, select one or more faces or one or more edges in the Geometry window, and then do one of the following: – Choose Merge Cells on the Virtual Topology context toolbar. – Click right mouse button on the Virtual Topology object and select Insert> Virtual Cell from the context menu. – Click right mouse button in the Geometry window and select Insert> Virtual Cell from the context menu. Additional Related Information: • Virtual Topology Overview • Virtual Topology Context Toolbar • «Meshing: Virtual Topology» (in the Meshing help)

Object Properties The properties for this object include the following. For related information, refer to Using the Virtual Topology Properties Dialog to Edit Properties. Category General

Fields Cell Class — Read-only indication of cell class for selected Virtual Cell object. Geometry — Read-only indication of components that make up the Virtual Cell object. Suppressed — Read-only indication of suppression status of selected Virtual Cell object. Project to Underlying Geometry — Defines whether the mesh should project to the original underlying geometry (Yes) or faceted geometry (No).

Virtual Hard Vertex Defines a virtual hard vertex, which allows you to define a hard point according to your cursor location on a face, and then use that hard point in a split face operation.Virtual Hard Vertex objects do not appear in the tree. Creation Options: Highlight the Virtual Topology object. Select the face to split in the Geometry window. Position your cursor on the face where you want the hard point to be located, left-click, and do one the following: • Right-click in the Geometry window and select Insert> Virtual Hard Vertex at + from the context menu. • Choose Hard Vertex at + on the Virtual Topology context toolbar. Additional Related Information: • Virtual Topology Overview • Virtual Topology Context Toolbar • «Meshing: Virtual Topology» (in the Meshing help)

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Virtual Split Edge

Object Properties The properties for this object include the following. For related information, refer to Using the Virtual Topology Properties Dialog to Edit Properties. Category General

Fields Geometry — Read-only indication showing that one vertex makes up the Virtual Hard Vertex object. Suppressed — Read-only indication of suppression status of selected Virtual Hard Vertex object. Virtual Hard Vertex Location — Read-only indication of the XYZ location of the Virtual Hard Vertex object.

Virtual Split Edge Defines a virtual split edge. Virtual Split Edge objects do not appear in the tree. Creation Options: Highlight the Virtual Topology object, select the edge to split in the Geometry window, and then do the following: • To define the split location according to your cursor location on the edge, right-click in the Geometry window and select Insert> Virtual Split Edge at + from the context menu, or choose Split Edge at + on the Virtual Topology context toolbar. • To define the split without specifying the location, right-click in the Geometry window and select Insert> Virtual Split Edge from the context menu, or choose Split Edge on the Virtual Topology context toolbar. By default the split ratio will be set to 0.5, but it can be changed later using the Virtual Topology Properties dialog. Additional Related Information: • Virtual Topology Overview • Virtual Topology Context Toolbar • «Meshing: Virtual Topology» (in the Meshing help)

Object Properties The properties for this object include the following. For related information, refer to Using the Virtual Topology Properties Dialog to Edit Properties. Category General

Fields Geometry — Read-only indication of components that make up the Virtual Split Edge object. Suppressed — Read-only indication of suppression status of selected Virtual Split Edge object. Split Ratio — Defines the location of the split for the selected Virtual Split Edge object. Represented as a fraction of the total length of the edge. The default is 0.5.

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Objects Reference

Virtual Split Face Defines a virtual split face. Virtual Split Face objects do not appear in the tree. Creation Options: Highlight the Virtual Topology object, select two vertices on the face that you want to split in the Geometry window, and then do one of the following: • Choose Split Face at Vertices on the Virtual Topology context toolbar. • Click right mouse button on the Virtual Topology object and select Insert> Virtual Split Face at Vertices from the context menu. • Click right mouse button in the Geometry window and select Insert> Virtual Split Face at Vertices from the context menu.

Note Virtual Hard Vertex objects can be defined for use in split face operations. Additional Related Information: • Virtual Topology Overview • Virtual Topology Context Toolbar • «Meshing: Virtual Topology» (in the Meshing help)

Object Properties The properties for this object include the following. For related information, refer to Using the Virtual Topology Properties Dialog to Edit Properties. Category General

Fields Geometry — Read-only indication of components that make up the Virtual Split Face object. Suppressed — Read-only indication of suppression status of selected Virtual Split Face object. Vertices — Read-only indication showing that two vertices were selected.

Virtual Topology Represents all definitions of face or edge groups, and all definitions of virtual split edges, virtual split faces, and virtual hard vertices within a model. Each definition is represented in a Virtual Cell, Virtual Split Edge, Virtual Split Face, or Virtual Hard Vertex object, respectively. Virtual Cell, Virtual Split Edge, Virtual Split Face, and Virtual Hard Vertex objects do not appear in the tree.

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Virtual Topology Tree Dependencies: • Valid Parent Tree Object: Model • Valid Child Tree Objects: Comment, Figure, Image Insertion Options: Use any of the following methods after highlighting Model object: • Choose Virtual Topology on Model context toolbar. • Click right mouse button on Model object or in the Geometry window> Insert> Virtual Topology.

Note Only one Virtual Topology object is valid per Model. Additional Related Information: • Virtual Topology Overview • Virtual Topology Context Toolbar • «Meshing: Virtual Topology» (in the Meshing help) The following right mouse button context menu options are available for this object. • Generate Virtual Cells • Generate Virtual Cells on Selected Entities

Object Properties The Details view properties for this object include the following. The Lock position of dependent edge splits setting applies to virtual split edge behavior. Category

Fields

Definition

Behavior

Advanced

Generate on Update Merge Face Edges Lock position of dependent edge splits

Statistics

Virtual Faces — Read-only indication Virtual Edges — Read-only indication Virtual Split Edges — Read-only indication Virtual Split Faces — Read-only indication Virtual Hard Vertices — Read-only indication Total Virtual Entities — Read-only indication

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Mechanical: CAD System Information For detailed CAD-related information specific to the ANSYS DesignModeler application and ANSYS Workbench, see the CAD Integration section of the product help. When accessing the ANSYS Workbench Help from the Help menu, click the Contents tab and open the CAD Integration folder in the hierarchical tree. The CAD Integration section includes topics about: • Overview • Geometry Interface Support for Linux and Windows • Project Schematic Presence • Mixed import Resolution • CAD Configuration Manager • Named Selection Manager • Caveats and Known Issues • Installation and Licensing • File Format Support (with information specific to the Mechanical application) ACIS AutoCAD BladeGen CATIA Creo Elements/Direct Modeling Creo Parametric (formerly Pro/ENGINEER) ANSYS DesignModeler GAMBIT IGES Inventor JT Open Monte Carlo N-Particle NX Parasolid Solid Edge SolidWorks SpaceClaim STEP • ANSYS Teamcenter Connection • SpaceClaim Related to CAD Integration Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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CAD System Information • Frequently Asked Questions • Troubleshooting • Glossary • Updates Mechanical application topics: General Information (p. 1414)

General Information Body Filtering Property There are four body filtering properties: Process Solid Bodies, Process Surface Bodies, Process Line Bodies and Mixed Import Resolution. Their value is set in the Project Schematic and they determine what bodies will get imported to the Mechanical application. The default setting is: Yes for Solid and Surface Bodies, No for Line Bodies and, None for Mixed Import Resolution.

Material Properties The CAD system interfaces will process only the isotropic material type.

Multiple Versions of CAD Systems For most CAD systems, you cannot use geometry that was created in a newer version of the same CAD system. For example, if you have both SolidWorks 2013 and SolidWorks 2012 installed, but only the 2012 version is registered, and you attempt to insert geometry created in SolidWorks 2013 from the Project Schematic, the registered 2012 version will not recognize the geometry created in the 2013 version.

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Mechanical Troubleshooting Problem Situations (p. 1415) Recommendations (p. 1433)

General Product Limitations This section describes limitations that can be present in the Mechanical application during certain conditions. • Color coding may change or disappear when displaying shared topologies using both the By Connection edge coloring and the Section Plane features. The By Connection feature displays connectivity color coding, while the Section Plane feature is used to cut or slice the model to view its interior. • When you are running Mechanical version 14.0 or any later version on a Linux system, you may experience graphical distortions when animating results, rotating an animation of results, as well as zooming in and/or out on your results. • When exporting video files, the Aero Theme display mode in Windows 7 is incompatible with the screen capture used in Mechanical. If you are running Windows 7, select a Basic Theme display mode to restore this capability. • When using Nice DCV to remotely connect to a Linux machine running Mechanical, you may encounter display issues when using the Report or Print Preview features. To correct this issue, temporarily turn off the DCV in the Nice DCV control panel, generate the Report or Print Preview, and then turn DCV back on once again.

Problem Situations A Linearized Stress Result Cannot Be Solved. A Load Transfer Error Has Occurred. Although the Exported File Was Saved to Disk Although the Solution Failed to Solve Completely at all Time Points. An Error Occurred Inside the SOLVER Module: Invalid Material Properties An Error Occurred While Solving Due To Insufficient Disk Space An Error Occurred While Starting the Solver Module An Internal Solution Magnitude Limit Was Exceeded. An Iterative Solver Was Used for this Analysis At Least One Body Has Been Found to Have Only 1 Element At Least One Spring Exists with Incorrectly Defined Nonlinear Stiffness Animation Does not Export Correctly Application Not Closing as Expected Assemblies Missing Parts CATIA V5 and IGES Surface Bodies Constraint Equations Were Not Properly Matched Error Inertia tensor is too large Failed to Load Microsoft Office Application Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Troubleshooting Illogical Reaction Results Large Deformation Effects are Active MPC equations were not built for one or more contact regions or remote boundary conditions One or More Contact Regions May Not Be In Initial Contact One or more MPC contact regions or remote boundary conditions may have conflicts One or More Parts May Be Underconstrained One or More Remote Boundary Conditions is Scoped to a Large Number of Elements Problems Unique to Background (Asynchronous) Solutions Problems Using Solution Running Norton AntiVirusTM Causes the Mechanical Application to Crash The Correctly Licensed Product Will Not Run The Deformation is Large Compared to the Model Bounding Box The Initial Time Increment May Be Too Large for This Problem The Joint Probe cannot Evaluate Results The License Manager Server Is Down Linux Platform — Localized Operating System The Low/High Boundaries of Cyclic Symmetry The Remote Boundary Condition object is defined on the Cyclic Axis of Symmetry The Solution Combination Folder The Solver Engine was Unable to Converge The Solver Has Found Conflicting DOF Constraints Problem with RSM-Mechanical Connection Unable to Find Requested Modes You Must Specify Joint Conditions to all Three Rotational DOFs

A Linearized Stress Result Cannot Be Solved. … The path is not entirely contained within the finite element mesh. To solve a Linearized Stress result, a necessary condition is that the associated path be totally contained within the model. If the start/endpoints of the path are not within the model (likely to occur when the mesh is coarse and when using the XYZ Coordinate toolbar button for picking), you can use the Snap to mesh nodes feature to adjust the endpoints to be coincident with the nearest nodes in the mesh. Occasionally however, other internal “knots” of the path are not inside the model due to a hole or other missing material in the model. These situations can prevent the solving of a Linearized Stress result and cause this error message to appear, even after using the Snap to mesh nodes feature. To verify that a discontinuity is the cause of the error, apply a result other than a Linearized Stress result to that path, and solve it. By doing so you will take advantage of the fact that other results do not require that the full path be inside the model. The results are displayed and discontinuities are indicated by any gaps or missing fields shown in the Graph and Tabular Data windows. The following example illustrates a Total Deformation result where gaps in the Graph window and empty fields in the Tabular Data window provide evidence of discontinuities.

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Problem Situations

A Load Transfer Error Has Occurred. … A load could not be applied to small or defeatured entity. Please see the Troubleshooting section of the Help System for more information. At least one load is not able to be applied. This may be due to mesh-based defeaturing of the geometry. You can modify the mesh defeaturing settings to restore the nodes and elements where the loads need to be applied. Another possible reason could be that the Details View property Send to Solver was incorrectly set to No for the node-based Named Selection used for some Direct FE boundary condition scoping.

Although the Exported File Was Saved to Disk … the Microsoft Office application failed to load. See the Troubleshooting section for details. This message is displayed when you have chosen to export a file to Microsoft Excel, but the Microsoft application is either not supported or not installed correctly. The Microsoft Excel file is still exported and can be opened provided the application is resident. To prevent this error message from appearing again, you can either install Microsoft Excel or set Automatically Open Excel to No in the Export preferences, accessible from the Main Menu under Tools> Options.

Although the Solution Failed to Solve Completely at all Time Points. … partial results at some points have been able to be solved. Refer to Troubleshooting in the Help System for more details. This message displays if for some reason (such as non convergence or the user choosing the Stop button) the simulation does not run to completion, but the solution does produce at least some results that can be post processed. If such a condition occurs, any applicable results in the tree that you request will be calculated (that is, they are defined at a sequence number or time that has been solved). These results will be assigned a Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Troubleshooting green check state (up to date) but the solution itself will still be in an obsolete state because it is not fully complete. Use the Evaluate Results right mouse button option on a Solution object or a result object in order to additionally postprocess the partial solution. See Unconverged Results (p. 876) for further details.

An Error Occurred Inside the SOLVER Module: Invalid Material Properties … Please see the Troubleshooting section of the Help system for possible causes. Check the following:

Material Definition Check the Details view for each part to see that you selected the correct material for each part. Go to Engineering Data to edit and check your material files and data and to verify the material definitions (including numbers and units). Note that, depending on the type of result, you will have a minimum of properties to be set.

Structural, Vibration, Harmonic, and Shape Results: • Need to define the Modulus of Elasticity • If you don’t define the Poisson’s Ratio it will default to 0.0. Also note that the Solver engine will not accept values of Poisson’s Ratio smaller than 0.1 or larger than 0.4 for Shape Results. • For Vibration and Harmonic results, include the Mass Density of your material. • For Thermal-stress results, you will need the Coefficient of Thermal expansion.

Thermal Results: Thermal conductivity is required. Can be constant or temperature-dependent. Specific Heat is required in a thermal transient analysis. Can be constant or temperature-dependent.

Check Thermal Data For thermal analysis, go to the Engineering Data to edit and check thermal conductivity in the material files and to check thermal convection in the convection files. Verify the ‘smoothness’ of the temperaturedependent conductivity data and convection data. Non-smooth curves will lead to Solve failures.

Electromagnetic Materials — Minimum Requirements For a Conductor scoped to a body, the associated material must have either Resistivity or Orthotropic Resistivity specified in order for the simulation to continue on to a solve. For all materials in an electromagnetic simulation, one of the following four conditions must be met. These conditions are mutually exclusive of each other so only one condition can exist at a time for a material. • Linear “Soft” Magnetic Material properties specified: Either Relative Permeability or Linear Orthotropic Permeability are set.

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Problem Situations • Linear “Hard” Magnetic Material properties specified. Only Linear “Hard” Magnetic Material property is set. • Nonlinear “Soft” Magnetic Material properties specified: Either only BH Curve or BH Curve and Nonlinear Orthotropic Permeability are set. • Nonlinear “Hard” Magnetic Material properties specified: Only Demagnetization BH Curve is set.

An Error Occurred While Solving Due To Insufficient Disk Space … Please see the Troubleshooting section of the Help system for more information. Possible reasons that this message appears: • You may be running out of disk space during the Mechanical APDL solution due to the writing of large solution files. Verify that there is sufficient free disk space on the drive where the solver directory exists. • You do not have write permissions to the solution directory. • Files from a previous Workbench or Mechanical APDL session already reside in the solution directory.

An Error Occurred While Starting the Solver Module To get further information on what the issue may be, insert a Solution Information object under Solution in the tree, and view the contents. Possible reasons that the solver may fail are: • Insufficient memory — You may not have enough virtual memory assigned to your system. To increase the allocation of virtual memory (total paging file size), go to Settings> Control Panel> System (on your Windows Start Menu). Click the Advanced tab and then click Performance Options. Increase the size of your virtual memory. • Insufficient disk space — You may not have enough disk space to support the increase in virtual memory and the temporary files that are created in the analysis. Be sure you have enough disk space or move to an area where you have enough. • Corrupt product installation • License request rejected • The startup directory for cmd.exe has been overridden by the AUTORUN option and as a result causes the solver to be unable to locate the solver input files.

Solving and UNC Paths If a Workbench database resides on a UNC path (for example, \\pghxpuser\Shares) for which you have write permissions, the ANSYS input file will be written successfully but will fail to start the solver executable. To solve, map a drive to the location and then reopen the project. If you did not have write permissions, Workbench will instead write the ANSYS input file to your temp directory (%tmp%) and perform a solution from that directory.

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Troubleshooting

An Internal Solution Magnitude Limit Was Exceeded. … Please check your Environment for inappropriate load values or insufficient supports. Please see the Troubleshooting section of the Help System for more information. In most cases this message will occur if your model is improperly constrained or extremely large load magnitudes are applied relative to the model size. First check that the applied boundary conditions are correct. In some cases, loads that are self-equilibrating with no support may be desired. To help in these cases, if this message occurs, consider adjusting the weak spring stiffness or turning on inertia relief.

An Iterative Solver Was Used for this Analysis …However, a direct solver may enhance performance. Consider specifying the use of a direct solver. An iterative solver was used to obtain the solution; however, a large number of iterations were needed in order to get a converged answer. By default, the program will either choose a direct or iterative solver based on analysis type and geometric properties. (In general, thin models perform better with a direct solver while bulky models perform better with an iterative solver.) However, sometimes the iterative solver is chosen when the direct solver would have performed better. In such cases, you may want to force the use of the direct solver. You may specify the solver type in the Details view of the Analysis Settings folder.

At Least One Body Has Been Found to Have Only 1 Element …in at least 2 directions along with reduced integration. This situation can lead to invalid results. Consider changing to full integration element control or meshing with more elements. Refer to Troubleshooting in the Help System for more details. This scenario is based on the following conditions: • Structural solid model. • Brick meshes that have only 1 element in less then 2 directions. • Reduced element integration is assigned (This can happen by default if Element Control in the Geometry object is set to Program Controlled.). If the above conditions are met, there is a strong likelihood that your analysis will excite hourglass modes. In such cases solver pivot warnings will be reported and nonphysical deformations will result (see examples below). If this occurs, first determine which bodies have one element through the thickness (Right-click in Geometry window, choose Go To> Bodies With One Element Through the Thickness, and observe selected body objects in the tree). The offending bodies can then be corrected by doing one of the following: • Modify the mesh to have more than 1 element in at least 2 directions. This will remove the hourglass modes in most cases. In rare cases you may need to modify the mesh such that more than 1 element exists in all 3 directions. • Use Full integration on the offending bodies. • Consider using lower order elements.

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Problem Situations Example of a «bad» mesh for reduced integration:

Example of a «good» mesh for reduced integration:

At Least One Spring Exists with Incorrectly Defined Nonlinear Stiffness The force-deflection curve is incorrectly defined using tabular input for nonlinear stiffness for one or more spring objects existing in the model, see the details in COMBIN39 element description for more information.

Note Support Requirements • Tabular Data requires at least two rows of data. • The properties Longitudinal Damping and Preload are not applicable for Springs with nonlinear stiffness.

Animation Does not Export Correctly When exporting an AVI file, make sure that you keep the Workbench module window in front of other windows until the exporting is complete. Opening other windows in front of the module window before the exporting is complete may cause those windows to be included in the AVI file capture.

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Troubleshooting

Application Not Closing as Expected During shutdown, if Mechanical is responding slowly, that is, taking two or more minutes to close, you may want to review your Filesystem Settings.

Assemblies Missing Parts When reading assemblies from CATIA V5, all part files that are referenced by assemblies must be accessible in order for the importing to occur.

CATIA V5 and IGES Surface Bodies CATIA V5 and IGES surface bodies consisting of closed faces are transferred as solid bodies.

Constraint Equations Were Not Properly Matched … for all node pairs across the low and high sector boundaries in the cyclic symmetry. Please see the Troubleshooting section of the Help System for more information This message may occur if the solver does not succeed to reproduce the exact pairing of nodes between the low and high sector. An approximate technique was used to group like nodes and distribute the loads, but this can reduce solution accuracy.

Error Inertia tensor is too large This message is shown by the LS-DYNA solver if your model includes rigid bodies with large dimensions, for example a few meters in length. Such rigid geometries cause the inertia tensor limit of the solver to be exceeded. You can attempt to resolve this issue by running the double precision LS-DYNA solver, which has a much larger inertia tensor limit. The double precision solver executable can be accessed with the -dp command line option as follows LSDYNA120.exe -dp.

Failed to Load Microsoft Office Application … See the Troubleshooting section for details. This message is displayed when you have chosen a feature that is dependent on a Microsoft Office application, such as exporting a file to Microsoft Excel, and the related Microsoft Office application is not installed correctly.

Illogical Reaction Results Cause Loads, supports, or contact items are applied to the same or shared topology.

Reason It is unclear or ambiguous as to which reaction should be attributed to which support, load, or contact item. Refer to this Note for details.

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Problem Situations

Large Deformation Effects are Active … Which may have invalidated some of your applied supports such as displacement, cylindrical, frictionless, or compression only supports. Refer to Troubleshooting in the Help System for more details. In a large deformation analysis, the program updates the nodal coordinates as the solution progresses towards the final configuration. As a result, supports that fix only some of the degrees of freedom of a node but not all (for example fix only UX=0), may become invalid as the model’s nodal coordinates and thus nodal rotation angles are updated. The imposed DOF displacement directions do not change even though rotation angles change. This may or may not be a desirable situation. A classic example is a simple torsion of a rod. Initially the nodes at zero degrees have a circumferential direction of UY but after a twist of 90 degrees, have a circumferential direction of UX. The user is responsible for determining if any nodal rotation at the support is significant enough to cause undesired results. The following is a list of supports which only fix the movement of a node partially and thus are susceptible to large deformation effects: • Displacement • Cylindrical support • Frictionless In addition a Compression Only Support may be susceptible to large deformation effects because if large sliding occurs, the face can literally «slide off» the compression only support.

MPC equations were not built for one or more contact regions or remote boundary conditions … Due to potential conflicts with the cyclic symmetry constraints. This may reduce solution accuracy. Please refer to the Troubleshooting section. Cyclic symmetry is enforced with the help of constraint equations between pairs of nodes on the low and high sector boundaries respectively. When such nodes also participate in MPC contact, which requires constraint equations of its own, conflicts may arise. Please review results carefully, since the MPC contact will be compromised at these locations.

One or More Contact Regions May Not Be In Initial Contact … Check results carefully. Refer to Troubleshooting in the Help System for more details. During the solution it was found that one or more of the contact pairs was not initially in contact. You may check the solution output located in the Worksheet of a Solution Information object to determine exactly which contact pairs are initially open, and take the appropriate action. • This message is expected if a contact pair is meant to be initially open and may become closed after the load application.

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Troubleshooting • If initial contact was desired and the contact pair has a significant geometric gap, setting the Pinball Radius manually to a sufficiently large value may be required. • If symmetric contact is active, it is possible that one pair may be initially open and its symmetric pair be initially in contact. Check the solution output to confirm this.

One or more MPC contact regions or remote boundary conditions may have conflicts …With other applied boundary conditions or other contact regions. This may reduce solution accuracy. Tip: You can graphically display FE Connections from the Solution Information Object. Refer to Troubleshooting in the Help System for more details. During solution it was found that one or more contact pairs using MPC (multi point constraint) contact formulation overlaps with another contact region or boundary condition. The same is true for remote boundary conditions overlapping with another contact region or boundary condition. Due to the fact that MPC formulation can cause over constraint if applied to the same nodes more than once, the program may have not been able to completely bond the desired entities together. You may check the solution output located in the Worksheet of a Solution Information object to determine which pairs and nodes are affected by this condition. Specifically this can happen when: • A contact pair entity (either an edge or face) also has a Dirichlet (prescribed displacement/temperature) boundary condition applied to it. In this case the MPC constraints will not be created at nodes that have prescribed conditions thus possibly causing parts to lose contact. Sometimes this warning may be disregarded in cases such as a large face with a fixed support at one edge and a contact pair on another. If it is determined that overlap does indeed exist, consider relocating the applied support or using a formulation other than MPC. • Two MPC contact pairs share topology (such as a face or an edge). Again it is possible for one or both of these pairs to lose contact. This message may especially occur when edge/face contact is automatically generated by the program because often 2 complementary contact pairs (that is, edge part 1/face part 2 and edge part 2/face part 1) are created. Often in this case the message can be ignored after verifying result correctness and if necessary, deleting/suppressing one of the inverse pairs. This condition may also occur when 1 part (typically a surface body), is being contacted by 2 or more parts in the same spatial region. In this case it is possible for one or more of the parts to lose contact. Consider reducing the Pinball Radius to avoid overlap or changing one or more of the regions in question to use a contact formulation other than MPC. • When MPC contact is used to connect rigid bodies and joints, the overconstraint situation can sometimes occur.

One or More Parts May Be Underconstrained …and experiencing rigid body motion. This message may occur for one of several reasons: If the program detects that the model may be underconstrained, weak springs will be added to the finite element model to help obtain a solution. In addition, the program will automatically add weak springs if unstable contact (frictionless, no separation, rough) or compression only supports are active in order to make the problem more numerically stable. Since the weak springs have a low stiffness relative to the model stiffness, they will not have an effect on a properly constrained model. If you are confident that weak springs are not needed for a solution

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Problem Situations and the program adds them anyway, you may disable them by setting the Weak Springs option to Off in the Details view of the Analysis Settings object.

One or More Remote Boundary Conditions is Scoped to a Large Number of Elements …which can adversely affect solver performance. Consider using the Pinball setting to reduce the number of elements included in the solver. Remote boundary conditions scoped to a large number of elements can cause the solver to consume excessive amounts of memory. Point masses in an analysis where a mass matrix is required and analyses that contain remote displacements are the most sensitive to this phenomenon. If this situation occurs, consider modifying the Pinball setting to reduce the number of elements included in the solver. Forcing the use of an iterative solver may help as well. The reason for the excessive memory consumption is that the remote boundary conditions generate internal constraint equations to distribute the remote mass, displacement, or loads from one node of the model to all other selected nodes. As described in Chapter 15.14. Constraint Equations, in the Mechanical APDL Theory Reference, constraint equations could change a sparse matrix (for example, a stiffness matrix, mass matrix, or damping matrix) to a dense matrix. An increase in the number of constraint equations used increases the density of the final matrix, which in turn places a higher demand for more memory (or longer CPU time) in the solution of a problem. Normally, if the maximum number of remote nodes selected is about 3000, then the increased memory usage or CPU time is not significant. Caution should be taken to not use too many remote nodes in these applications. Other techniques are available to distribute loads or masses. For example, to distribute a point mass to the entire model, you might consider specifying density directly instead of using the point mass approach.

Problems Unique to Background (Asynchronous) Solutions Consider the following hints when troubleshooting background (asynchronous) solution problems: • For security reasons, RSM will not allow any job to be run by the «root» user on Linux, including primary and alternate accounts. • It may sometimes be necessary for you to enter the full path to the solver executable file in the Solve Process Settings. • It may sometimes be necessary for you to enter the full path to the Linux working directory in the Linux Working Folder field of the Solve Process Settings. • The LSF administrator should configure the Workbench job server to disallow multiple, simultaneous jobs. Two solves running on the same server will interfere with each other, preventing successful completion of each. • To help in debugging solver startup problems on the remote machine, it is sometimes useful for you to use the Solution Information object under the Solution object in the tree. The Solution Information object will show the contents of the solve.out file that the remote solver produced, if the application was able to start. • When using the Stop Solution option to stop a solve running on a Linux machine, it is possible that the solver will continue to run on that machine even though the Mechanical application thinks it has stopped. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Troubleshooting If this happens and you don’t want the solve job to continue on the Linux machine it will be necessary for you to kill the process manually. The ability to solve to two different Linux machines simultaneously is not allowed. • The solve command may have failed to execute on the remote Linux server. Verify the command’s spelling and/or path. Solve commands are issued to the remote server using the rexec interface. Failures may occur if the resulting path ($path) is insufficient. $path can be verified by issuing rexec on the command prompt on the local machine. For example: rexec machinename -l username echo $path > diagnosticsfile (where «l» is the letter «el)» The machinename and username match the entries in the Solve Process Settings, and diagnosticsfile corresponds to the recipient on the local machine for the command output.

Note After issuing rexec, if you receive the following message, rexec isn’t enabled on the remote Linux server. This feature must be enabled on the remote Linux server in order for the solution to proceed. > rexec:connect:Connection refused rexec: can’t establish connection If the path to the solve command is unavailable on the remote server, it can be added to user or system-wide files that initialize the startup shell (for example, .cshrc or /etc/csh.login on Cshells). Consult the Linux server’s rexec interface and appropriate shell manual pages for details. • If you cannot make ASCII transfers to a Linux server, changes need to be made on the server. Background solutions on a remote Linux server use file transfer protocol (ftp). Therefore, the system administrator must install ftp and enable it. Ftp uses ASCII transfer mode to convert PC text to Linux text. If ASCII mode is disabled, it is not obvious because error messages do not imply this. On some ftp servers (vsftpd, for example), by default, the server will pretend to allow ASCII mode, but in fact, will ignore the request. You will need to ensure that the ASCII upload and download options are enabled to have the server actually do ASCII mangling on files when in ASCII mode. To enable these options, the system administrator should consult the operating system documentation. The following vsftp.conf modification procedure is Linux platform specific and is provided as an example only. 1. In /etc/vsftpd/vsftpd.conf, uncomment the following lines (that is, remove the # at the beginning of these lines): ascii_upload_enable=YES ascii_download_enable=YES 2. Restart the server.

Problems Using Solution If Solution fails to complete, try the following suggestions.

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Problem Situations

Verify the Environment Verify that the loads and supports in the Environment meet the requirements for Stress, Thermal, Thermal-Stress, Shape or Vibration. You can verify the environment quickly by looking at the icons adjacent to each environment item in the Tree Outline. A green check indicates that the requirements are met. A indicates that the requirements were not met.

Check System Requirements Verify that your system meets the minimum requirements at the time you start Solution. Disk space and memory may fluctuate depending on how the system is used. See also General Solver Error.

For Thin-Walled or Finely Detailed Parts If your parts contain features whose size or thickness is extremely small in comparison to the principal dimensions of the assembly, try adjusting the variables used in modeling geometry. • Set the variable DSMESH DEFEATUREPERCENT to 1e-5. To set variables, click Tools> Variable Manager. • If that fails, change the setting to 1e-6.

Invalid or Poorly Defined Models At the end of the Solution procedure, the region of a part that caused the problem is usually labeled.

. If the geometry that is notated looks valid, but is small compared to the rest of the model, adjusting the Sizing Control may correct the problem.

Running Norton AntiVirusTM Causes the Mechanical Application to Crash If the Norton AntiVirusTM product is running and you choose Allow the entire script once to resolve a script error, the Mechanical application crashes. Choose Authorize this script to allow the Mechanical application to function normally.

The Correctly Licensed Product Will Not Run If you have installed a license file for a valid Mechanical product, but the product continues to run in read-only mode or, in the case of an upgrade to a higher product, continues to run the lower product, make sure you have specified the correct product in the launcher.

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Troubleshooting This situation can occur if you install the Mechanical application before creating your license file. In this case, the Mechanical application will run only in read-only mode. When you create your license file later, you must choose a license under Mechanical APDL Product Launcher in the Start menu. Once there, select the product that you have licensed to reset the default to the correct product. Otherwise, the Mechanical application will continue to run in read-only mode. This situation can also occur if you upgrade your license to a higher Mechanical product. Again, you must choose a license under Mechanical APDL Product Launcher in the Start menu. Then reset to the appropriate product. Otherwise, the Mechanical application will continue to run as the lower, previously-licensed product.

The Deformation is Large Compared to the Model Bounding Box … Verify boundary conditions or consider turning large deflection on. This message will be displayed any time the software detects nodal deformations exceeding 10% of the model diagonal. Exceeding 10% of this length suggests model mechanics that depart from linearity in response to the applied boundary conditions. Load magnitudes, surface body thicknesses, and contact optionsoe, if applicable, should be verified. If these are intended, a nonlinear analysis is advised. To request a nonlinear analysis, set Large Deflection to On in the Details view of the Analysis Settings folder.

The Initial Time Increment May Be Too Large for This Problem … Check results carefully. Refer to Troubleshooting in the Help System for more details. This message will appear if the program determines that the initial time increment used in the thermal transient analysis may be too large based on the «Fourier modulus» (Fo). This dimensionless quantity can be used as a guideline to define a conservative time step based on thermal material properties and element sizes. It is defined as: Fo = k (∆t) / ρ c (lengthe2) where: lengthe = Average element length ∆t = Time step k = Thermal Conductivity c = Specific Heat ρ = Density Specifically this warning will be issued if the program finds that the Fourier modulus is greater than 100, that is, Fo > 100. Stated in terms of the initial time step (ITS), this warning appears when the ITS is 100 times greater than the time step suggested by the Fourier modulus in the form expressed below: ∆t = lengthe2 / (k / (c ρ)) This check is done on a per body basis and the results are echoed in the Mechanical APDL output listing. For example: ********* Initial Time Increment Check And Fourier Modulus ********* Specified Initial Time Increment: .75 Estimated Increment Needed, le*le/alpha, Body 1: 0.255118 Estimated Increment Needed, le*le/alpha, Body 2: 1.30416

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Problem Situations Estimated Increment Needed, le*le/alpha, Body 3: 0.158196 Estimated Increment Needed, le*le/alpha, Body 4: 0.364406

If this warning is issued make sure that the specified time step sizes are sufficiently fine to accurately capture the transient phenomenon. The proper use of this guideline depends on the type of problem being solved and on accuracy expectations.

The Joint Probe cannot Evaluate Results …A possible cause is that the joint is a fixed body-body joint on a rigid body. This message displays because fixed body-body joints on rigid bodies do not report a reaction. See the Probes section of the help for more information.

The License Manager Server Is Down Unless a connection is reestablished, the Mechanical application will exit in nn minutes. Cause This message occurs in a one-server license environment if your license manager has quit running. In a three-license server environment, the ANSYS license manager must be running on at least two of the three license server machines at all times. If two of the license server machines go down, or two of the machines are not running the license manager, this error message will appear in the program output or in a message box. The program will continue to run for nn minutes to allow the license manager to be restarted or to be started on a second machine if using redundant servers. When the message first displays, nn = 60. The message then reappears every five minutes with nn displaying the elapsed time at each 5 minute increment (55, 50, 45, etc.) until the connection is established.

Resolution When this error message appears, start the license manager on the other machines designated as license servers. If you get this message and determine that the license manager is still running, and you are running in a one-server environment, then the IP address of the license server machine was changed while the application was running (this is usually caused by connecting to or disconnecting from an Internet Service Provider (ISP) that dynamically allocates IP addresses). To correct this situation, you must return the IP address to the same address that the license server had when the application was started. If the IP address changes after you start the application (either because you connected to or disconnected from your ISP), you can correct the error by restarting the application. You should not need to restart the license manager. You can avoid this problem by remaining connected to or disconnected from the ISP the entire time you are running the application.

Linux Platform — Localized Operating System Specific to the Linux platform: if you are using a localized operating system (such as French or German), or set your preferences to use regional settings for numbers and dates (comma delimiter versus period), there is a discrepancy between applications: The ANSYS Workbench will honor the setting and display the numbers with comma delimiter. However, some of the components (e.g. Geometry, Meshing, Mechanical, etc.) can only recognize periods; numbers will be displayed and entered with periods. As a result, you may have to use commas when working in Workbench, and periods when working within those components. If this causes any inconvenience or confusion, define the «LANG» environment Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Troubleshooting variable and set to «en-us» (e.g. «setenv LANG en-us» for csh shell) to force ALL applications (including Workbench) to use the period delimiter consistently throughout. Note that setting LANG to en-us may also cause some strings to be displayed in English, even if your language preference was set to a nonEnglish language. Within Mechanical, analysis settings for Explicit Dynamics and Rigid Dynamics, as well as Imported Load mapping settings are not localized. If you are using a localized operating system (such as French or German), you must set the following VisualMainWin control on any machines running these applications in order for these applications to recognize the correct numerical format. ANSYS Workbench must already be installed before setting this control. 1. cd to: <wb_install directory>/v140/aisol

2. Issue the following command: ./.workbench -cmd mwcontrol

3. On the MainWin Control Panel, select Regional Settings. 4. Select the Regional Settings tab. 5. Change the language in the drop-down to match the language you want to use.

The Low/High Boundaries of Cyclic Symmetry … Have been found to include one or more nodes along the axis of symmetry.This may reduce solution accuracy. Please refer to the Troubleshooting section. Cyclic symmetry does not support the presence of nodes along the axis of symmetry. There, the node pair on the high and low sector boundary degenerates to a single node. Consider removing the axial nodes, fixing the nodes, or providing a much finer mesh in the vicinity.

The Remote Boundary Condition object is defined on the Cyclic Axis of Symmetry … This may reduce solution accuracy. Please refer to the Troubleshooting section in the Help System. This message is displayed when the software detects that a Remote Boundary Condition object is defined on the Cyclic Axis of Symmetry. To obtain accurate results, it is necessary to scope that Remote Boundary Condition to a Remote Point, which should be properly constrained by a Remote Displacement. In addition, non-physical results might be exposed if the Remote Boundary Condition’s Behavior option is specified as Deformable.

The Solution Combination Folder …is underdefined due to invalid input environments. When the Solution Combination Folder is underdefined, verify that:

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Problem Situations • At least one environment is checked in the Solution Combination Worksheet. • The selected environments are static structural analyses. • The selected environments do not contain convergence. • The Solution folder within one or more selected environments makes use of Cyclic Solution Display options other than Program Controlled. For more information, see Solution Combinations (p. 1019).

The Solver Engine was Unable to Converge Cause The solver engine was unable to converge on a solution of a nonlinear problem.

Recommendations • When Advanced Contact is NOT Present in the Model … 1. Check for sufficient supports to prevent rigid body motion (structural) or check for thermal material curves or convection curves which rise and/or fall sharply over the temperature range (thermal). 2. If you encounter a convergence error during a thermal analysis that is using contact, consider modifying the Thermal Conductance property. • When Advanced Contact IS Present in the Model … 1. Check for sufficient supports to prevent rigid body motion or that contact with other parts will prevent rigid motion. 2. Check that the loading is of a reasonable nature. Unlike linear problems whose results will scale linearly with the loading, advanced contact is nonlinear and convergence problems may arise if the loading is too big or small in a real world setting. 3. If the contact type is frictionless, try setting the type to rough. This may help some problems to converge if any possible sliding is not constrained. 4. Check that the mesh is sufficiently fine on faces that may be in contact. Too coarse a mesh may cause inaccurate answers and convergence difficulties. 5. Consider softening the normal contact stiffness KN to a value of .1. The default value is 1 and may be changed by setting the Normal Stiffness. Smaller KN multipliers will allow more contact penetration which may cause inaccuracies but may allow problems to converge that would not otherwise. 6. If symmetric contact is being used (by default the contact is symmetric), consider using asymmetric contact pairs (p. 512). This may help problems that experience oscillating convergence patterns due to contact chattering. The program can be directed to automatically use asymmetric contact in the Details view of the Contact Folder.

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Troubleshooting

The Solver Has Found Conflicting DOF Constraints …at one or more nodes. Please refer to the Troubleshooting section in the Help System. A variety of boundary conditions in Workbench direct the solver to apply a specific value of displacement or rotation to one or more nodes. Among these are fixed supports, simple supports, rotational supports, frictionless supports, cylindrical supports, symmetry planes and displacements. Workbench also allows you to rotate nodes using the Nodal Orientation boundary condition. A typical example would be to apply non-zero displacements to two faces of a model that meet at an edge, especially when the displacements do not act in perpendicular directions. Nodes along the edge may find conflicting instructions as they are instructed to move different amounts along the same direction in space. If this is the case, consider modifying the non-zero displacements so they act in perpendicular directions. Although Workbench attempts to negotiate these constraints, along with the nodal rotations applied, there may be instances in which a node is directed to take on different and incompatible values of displacement or rotation by two or more of these boundary conditions. For such situations, Workbench will report a conflict. One example could be to apply non-zero displacements to two faces of a model that meet at an edge, especially when the displacements do not act in perpendicular directions. Nodes along the edge may find conflicting instructions as they are instructed to move different amounts along the same direction in space. If this is the case, consider modifying the non-zero displacements so they act in perpendicular directions. Another example could be when one or more nodal orientations are added in Workbench with other boundary conditions which are applied to same section of geometry (for example by selecting the same “Scope”, or one “Scope” being a part of the other). Each Nodal Orientation prescribes a Nodal Coordinate System to a subset of nodes. Only one Nodal Coordinate System can be prescribed to a given node. Whenever this condition is not met, Workbench creates an error that “The solver has found conflicting DOF constraints with Direct FE loading at one or more nodes”. Direct FE boundary conditions cannot be applied to nodes that are already scoped with geometrybased constraints which may modify Nodal Coordinate system.

Problem with RSM-Mechanical Connection If Mechanical appears to hang up as a result of a job processing in the RSM, select the right-mouse option Disconnect Job from RSM from the Solution folder to disconnect Mechanical from the current RSM job.

Unable to Find Requested Modes If this message occurs during a modal analysis, most likely a frequency search range was specified but no natural frequencies were found in the specified range. Either increase search range or specify that the first N frequencies be found. If this message occurs during an linear buckling analysis, verify that the loading is in the correct direction (that is, compressive) and that the structure is well constrained so that no rigid body motion can occur. If the applied boundary conditions appear to be correct, it is likely that a buckling failure will not occur.

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Recommendations

You Must Specify Joint Conditions to all Three Rotational DOFs …for one or more joints in the model. Please refer to the Troubleshooting section in the ANSYS Workbench Manual Rotations are not independent in 3D. You must define all three rotations for a Joint Condition before proceeding to a solve. The problem is mathematically different on the velocities, as the 3 components are perfectly independent, thus you can define any of the components.

Recommendations Microsoft ClearType edge smoothing option may cause font display problem If you use Microsoft ClearType edge smoothing method with Large size DPI setting, you may see distorted dimension text in DesignModeler and legend text in the Mechanical application. The problem occurs when the user minimizes or maximizes the Workbench window. In DesignModeler the display can be corrected on some machines by nudging the graphics window pane a pixel or two. This will cause a resize event in the graphics browser which will redraw the dimension text properly. Nudging the graphics window pane does not correct the problem in the Mechanical application, however. Alternatively, if the edge smoothing method is set to Standard instead of ClearType, then the text display appears correctly in both applets. Please note though, this is machine dependent, so the suggestions may not work on all machines. To ensure the text appears properly, it is recommended to turn off edge smoothing entirely.

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Appendix A. Glossary of General Terms API

Application Program Interface: This is a defined interface of functions that can be called by the scripts. This interface will remain reasonably constant and no functions will be removed without deprecation and warning.

Callout

A message that appears as a result of an action initiated within the wizard. Callouts usually point to a toolbar button, a row in the Details View (p. 11), or object in the Tree Outline (p. 3). The message contains descriptive and instructive text.

Context Menu

Provides a short list of options applicable to a specific object or window. To view a context menu, click the right mouse button on an object or in a window.

Context Toolbar

A toolbar containing options appropriate for the current level in the Tree Outline (p. 3).

Deprecate

When a function in the API is removed it will be deprecated and undocumented. This means that it will still be available for the next release, but will be removed in the future. A warning will be provided with a suggested alternative method of achieving the same function.

Details View

Provides information on the highlighted object in the Tree Outline (p. 3).

Displacement

A vector quantity used to measure the movement of a point from one location to another. The basic unit for displacement is (Length).

Double

Data type that can be assigned to real (decimal) numbers, e.g. 2.3462

Drag

Moving an on-screen object in the Tree Outline (p. 3) from one location to another using the mouse cursor while holding down the left button. The drag is interpreted as «move» if the object is dragged from the outline and «copy» if the object is dragged from the outline while holding down the Ctrl key

Edge

A selectable entity on a part that occurs at the intersection of two surfaces. In a surface model, an edge can also exist on the edge of one surface.

Elastic Strain

Normal elastic strain is a measure of the elongation or contraction of a hypothetical line segment inside a body per unit length. Normal elastic strain is dimensionless, however in practice it is common to assign normal elastic strain the basic unit of (Length / Length). Shear elastic strain is a measure of the change in angle that occurs between two initially perpendicular hypothetical line segment inside a body. The basic unit for shear elastic strain is radians. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Glossary of General Terms Face

A selectable area on a part bordered on all sides by edges. Periodic, nonboundary edged faces (like spheres) may occasionally appear.

Factor of Safety

Factor of safety is defined as the ratio of the limit strength of a material to the maximum stress predicted for the design. This definition of factor of safety assumes that the applied load is linearly related to stress (an assumption implicit in all calculations performed in the application). A factor of safety of less than one generally predicts failure of the design; in practice a factor of safety of one or greater is required to help avoid the potential for failure.

FEA

Finite Element Analysis. A robust and mature technique for approximating the physical behavior of a complex system by representing the system as a large number of simple interrelated building blocks called elements.

Fundamental Frequencies

The fundamental frequencies are the frequencies at which a structure under free vibration will vibrate into its fundamental mode shapes. The fundamental frequencies are measured in Hertz (cycles per second).

Heat Flux

A measure of heat flow per unit area. The basic unit for heat flux is (Heat / Length*Length).

Int

Data type that can be assigned to integer (whole) numbers, e.g.2

Margin of Safety

Margin of safety is always equal to the factor of safety minus one.

Multiple Select

Select more than one surface, edge or vertex by holding the Ctrl key.

Object

A set of information displayed visually as an icon (usually in the Tree Outline (p. 3)).

Python

This is a non-proprietary scriptable programming language that is commonly used throughout the world. Full details can be found at www.python.org. A number of debuggers are available to enable a script to be stepped through.

Reference Temperature

The reference temperature defines the temperature at which strain in the design does not result from thermal expansion or contraction. For many situations, reference temperature is adequately defined as room temperature. The reference temperature is defined for each body in a model. A coefficient of thermal expansion curve will be adjusted for the body’s reference temperature if the reference temperature of the coefficient of thermal expansion is different.

Right-Hand Rule

The right-hand rule is a convenient method for determining the sense of a rotation defined by a vector: close your right hand and extend your thumb in the direction of the vector defining the rotation. Your fingers will indicate the sense or direction of the rotation. The direction in which your fingers curl is the positive direction.

Rigid Body Motion

Might occur when the part is free to translate or rotate in one or more directions. For example, a body floating in space is free to move in the X-, Y-, and Z-directions and to rotate about the X-, Y-, and Z-directions.

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Stress

A measure of the internal forces inside a body. The basic unit for stress is (Force / Length*Length).

String

Data type that can be assigned to one or more characters of text, e.g. Hello World

Temperature

A scalar quantity used to measure the relative hotness or coldness of a point from one location to another. The basic units for temperature are degrees Fahrenheit or Celsius.

Vertex

A selectable entity on a part that occurs at the intersection of two or more edges.

World Coordinate System

The fixed global Cartesian (X, Y, Z) coordinate system defined for a part by the CAD system.

XML

eXtensible Markup Language: This is a standard layout of text based files in a metalanguage that enables users to define their own customized markup languages.

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Appendix B. Tutorials This section includes step-by-step tutorials that represent some of the basic analyses you can perform in the Mechanical Application. The tutorials are designed to be self-paced and each have associated geometry input files. You will need to download all of these input files before starting any of the tutorials. To access tutorials and their input files on the ANSYS Customer Portal, go to http://support.ansys.com/ training. The following tutorials are included within this section: Steady-State and Transient Thermal Analysis of a Circuit Board Cyclic Symmetry Analysis of a Rotor — Brake Assembly Using Finite Element Access to Resolve Overconstraint Actuator Mechanism using Rigid Body Dynamics Track Roller Mechanism using Point on Curve Joints and Rigid Body Dynamics Simple Pendulum using Rigid Dynamics and Nonlinear Bushing Fracture Analysis of a Double Cantilever Beam (DCB) using Pre-Meshed Crack Fracture Analysis of an X-Joint Problem with Surface Flaw using Internally Generated Crack Mesh Fracture Analysis of a 2D Cracked Specimen using Pre-Meshed Crack Interface Delamination Analysis of Double Cantilever Beam Delamination Analysis using Contact Based Debonding Capability Nonlinear Static Structural Analysis of a Rubber Boot Seal

Steady-State and Transient Thermal Analysis of a Circuit Board Problem Description The circuit board shown below includes three chips that produce heat during normal operation. One chip stays energized as long as power is applied to the board, and two others energize and de-energize periodically at different times and for different durations. A steady-state thermal analysis and transient thermal analysis are used to study the resulting temperatures caused by the heat developed in these chips.

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Tutorials

Features Illustrated • Linked analyses • Attaching geometry • Model manipulation • Mesh method and sizing controls • Constant and time-varying loads • Solving • Time-history results • Result probes • Charts

Procedure 1. Create analysis system. You need to establish a transient thermal analysis that is linked to a steady-state thermal analysis. a. Start ANSYS Workbench. b. From the Toolbox, drag a Steady-State Thermal system onto the Project Schematic. c. From the Toolbox, drag a Transient Thermal system onto the Steady-State Thermal system such that cells 2, 3, 4, and 6 are highlighted in red.

d. Release the mouse button to define the linked analysis system.

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Steady-State and Transient Thermal Analysis of a Circuit Board

2. Attach geometry. a. In the Steady-State Thermal schematic, right-click the Geometry cell, and then choose Import Geometry. b. Browse to open the file BoardWithChips.x_t. This file is available on the ANSYS Customer Portal; go to http://support.ansys.com/training. 3. Continue preparing the analysis in the Mechanical Application. a. In the Steady-State Thermal schematic, right-click the Model cell, and then choose Edit. The Mechanical Application opens and displays the model. b. For convenience , use the Rotate toolbar button to manipulate the model so it displays as shown below.

Note You can perform the same model manipulations by holding down the mouse wheel or middle button while dragging the mouse.

c. From the Menu bar , choose Units> Metric (m, kg, N, s, V, A) . 4. Set mesh controls and generate mesh. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Tutorials Setting a specific mesh method control and mesh sizing controls will ensure a good quality mesh. Mesh Method: a. Right-click Mesh in the tree and choose Insert> Method. b. Select all bodies by choosing Edit> Select All from the toolbar, then clicking the Apply button in the Details view. c. In the Details view, set Method to Hex Dominant, and Free Face Mesh Type to All Quad. Mesh Body Sizing – Board Components: a. Right-click Mesh in the tree and choose Insert> Sizing. b. Select all bodies except the board by first enabling the Body selection toolbar button, then holding the Ctrl keyboard button and clicking on the 15 individual bodies. Click the Apply button in the Details view when you are done selecting the bodies. c. Change Element Size from Default to 0.0009 m. Mesh Body Sizing – Board: a. Right-click Mesh in the tree and choose Insert> Sizing. b. Select the board only and change Element Size from Default to 0.002 m. Generate Mesh: • Right-click Mesh in the tree and choose Generate Mesh.

5. Apply internal heat generation load to chip. The chip on the board that is constantly energized represents an internal heat generation load of 5e7 W/m3. a. Select the chip shown below by first enabling the Body selection toolbar button, then clicking on the chip.

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Steady-State and Transient Thermal Analysis of a Circuit Board

b. Right-click Steady-State Thermal in the tree and choose Insert> Internal Heat Generation. c. Type 5e7 in the Magnitude field and press Enter. General items to note: • The applied loads are shown using color coded labels in the graphics. • Time is used even in a steady-state thermal analysis. • The default end time of the analysis is 1 second. • In a steady-state thermal analysis, the loads are ramped from zero. You can edit the table of load vs. time to modify the load behavior. • You can also type in expressions that are functions of time for loads. 6. Apply a convection load to the entire circuit board. The entire circuit board is subjected to a convection load representing Stagnant Air — Simplified Case. a. Select all bodies by choosing Edit> Select All. b. Choose Convection from the Environment toolbar. c. Import temperature dependent convection coefficient and choose Stagnant Air — Simplified Case. Note that the Ambient Temperature defaults to 22oC. i.

Click the flyout menu in the Film Coefficient field and choose Import Temperature Dependent (adjacent to the thermometer icon).

ii. Click the radio button for Stagnant Air — Simplified Case, then click OK. 7. Prepare for a temperature result. The resulting temperature of the entire model will be reviewed.

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Tutorials • Right-click Solution in the tree under Steady-State Thermal and choose Insert> Thermal> Temperature. 8. Solve the steady-state thermal analysis. • Choose Solve from the toolbar. 9. Review the temperature result. • Highlight Temperature in the tree.

You have completed the steady-state thermal analysis, which is the first part of the overall objective for this tutorial. You will perform the transient thermal analysis in the remaining steps. Items to note in preparation for the transient thermal analysis: • If you highlight Initial Temperature under Transient Thermal in the tree, you will notice in the Details view, the read only displays of Initial Temperature and Initial Temperature Environment. In general, the initial temperature can be: – Uniform Temperature — where you specify a temperature for all bodies in the structure at time = 0, or – Non-Uniform Temperature — (as in this example) where you import the temperature specification at time = 0 from a steady-state analysis. • The initial temperature environment is from the steady-state thermal analysis that you just performed. By default the last set of results from the steady-state analysis will be used as the initial condition. You can specify a different set (different time point) if multiple result sets are available. 10. Specify a time duration for the transient analysis. A time duration of the transient study will be 200 seconds. • Under Transient Thermal, highlight the Analysis Settings object and enter 200 in either the Step End Time field in the Details view or in the End Time column in the Tabular Data window. Also note and accept the default initial, maximum, and minimum time step controls for this analysis.

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Steady-State and Transient Thermal Analysis of a Circuit Board 11. Apply internal heat generation to simulate on/off switching on first chip. A chip on the board is energized between 20 and 40 seconds and represents an internal heat generation load of 5e7 W/m3 during this period. a. Select the chip shown below by first enabling the Body selection toolbar button, then clicking on the chip.

b. Right-click Transient Thermal in the tree and choose Insert> Internal Heat Generation. c. Enter the following data in the Tabular Data window: • Time = 0; Internal Heat Generation = 0

Note Enter each of the following sets of data in the row beneath the end time of 200 s.

• Time = 20; Internal Heat Generation = 0 • Time = 20.1; Internal Heat Generation = 5e7 • Time = 40; Internal Heat Generation = 5e7 • Time = 40.1; Internal Heat Generation = 0 The Graph window reflects the data that you entered.

General items to note:

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Tutorials • Loads can be specified as one of three types: – Constant – remains constant throughout the time history of the transient. – Tabular (Time) – (as in this example) define a table of load vs. time. – Function – enter a function such as “=10*sin(time)” to define a variation of load with respect to time. The function definition requires you to start with a ‘=‘ as the first character. 12. Apply internal heat generation to simulate on/off switching on second chip. Another chip on the board is energized between 60 and 70 seconds and represents an internal heat generation load of 1e8 W/m3 during this period. a. Select the chip shown below by first enabling the Body selection toolbar button, then clicking on the chip.

b. Right-click Transient Thermal in the tree and choose Insert> Internal Heat Generation. c. Enter the following data in the Tabular Data window: • Time = 0; Internal Heat Generation = 0

Note Enter each of the following sets of data in the row beneath the end time of 200 s.

• Time = 60; Internal Heat Generation = 0 • Time = 60.1; Internal Heat Generation = 1e8 • Time = 70; Internal Heat Generation = 1e8 • Time = 70.1; Internal Heat Generation = 0 The Graph window reflects the data that you entered.

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Steady-State and Transient Thermal Analysis of a Circuit Board

13. Prepare for a temperature result. The resulting temperature of the entire model will be reviewed. • Right-click Solution in the tree under Transient Thermal and choose Insert> Thermal> Temperature. 14. Solve the transient thermal analysis. • Click the right mouse button again on Solution and choose Solve. The solution is complete when green checks are displayed next to all of the objects. You can ignore the Warning message and click the Graph tab. 15. Review the time history of the temperature result for the entire model. • Highlight the Temperature object. The time history of the temperature result for the entire model is evaluated and displayed.

– The Tabular Data window shows the min/max values of temperature at a time point. – By moving the mouse, you can move the bar along the Graph as shown, to any time, click the right mouse button and Retrieve this Result to review the results at a particular time. – You can also animate the solution. 16. Review the time history of the temperature result for each of the chips. Temperature probes are used to obtain temperatures at specific locations on the model. a. Right-click Solution and choose Insert> Probe> Temperature. b. Select the chip to which internal heat generation was applied in the steady state analysis and click the Apply button in the Details view. c. Follow the same procedure to insert two more probes for the two chips with internal heat generations in the transient thermal analysis. d. Right-click Solution or Temperature Probe and choose Evaluate All Results.

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Tutorials 17. Plot probe results on a chart. a. Select the three temperature probes in the tree and select the New Chart and Table button from the toolbar.

A Chart object is added to the tree.

b. Right-click in the white space outside the chart in the Graph window and choose Show Legend.

c. In the Details view, you can change the X Axis variable as well as selectively omit data from being displayed.

You have completed the transient thermal analysis and accomplished the second part of the overall objective for this tutorial. End of tutorial.

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Cyclic Symmetry Analysis of a Rotor — Brake Assembly

Cyclic Symmetry Analysis of a Rotor — Brake Assembly Program Description This tutorial demonstrates the use of cyclic symmetry analysis features in the Mechanical Application to study a sector model consisting of a rotor and brake assembly in frictional contact. With increased loading of the brake, the contact status between the pad and the rotor changes from “near”, to “sliding”, to “sticking”. Each of these contact states affects the natural frequencies and resulting mode shapes of the assembly. Three pre-stress modal analyses are used to verify this phenomenon.

Features Demonstrated • Cyclic Regions • Named Selections based on Criteria • Thermal Steady-State Analysis with Cyclic Symmetry • Static Structural Analysis with Cyclic Symmetry • Modal Analysis with Cyclic Symmetry • Generation of Restart Points • Modal Analysis with Nonlinear Prestress (Linear Perturbation)

Note The procedural steps in this tutorial assume that you are familiar with basic navigation techniques within the Mechanical application. If you are new to using the application, consider running the tutorial: “Steady-State and Transient Thermal Analysis of a Circuit Board” before attempting to run this tutorial.

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Analysis System Layout We will tour the different analysis systems that can leverage cyclic symmetry functionality. These comprise thermal, static structural and modal analyses: • A steady-state thermal analysis will be used to calculate the temperature distribution for the evaluation of any temperature-dependent material properties or thermal expansions in subsequent analyses. • A nonlinear static structural analysis is configured to represent the mechanical loading of the brake onto the rotor. Nonlinearities from large deformation and changes in contact status are included. • Modal analyses, each at different stages of frictional contact status, are established to compare the free vibration responses of the model. 1. Create the analysis systems. You need to establish a static structural analysis that is linked to a steady-state thermal analysis, then establish three modal analyses that are linked to the static structural analysis. a. Start ANSYS Workbench. b. From the Toolbox, drag a Steady-State Thermal system onto the Project Schematic. c. From the Toolbox, drag and drop a Static Structural system onto the Steady-State Thermal system such that cells 2, 3, 4, and 6 are highlighted in red.

d. The systems are displayed as follows:

e. To measure the free vibration response, go to the Toolbox, drag and drop a Modal system onto the Static Structural system such that cells 2, 3, 4, and 6 are highlighted in red.

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Cyclic Symmetry Analysis of a Rotor — Brake Assembly f.

Repeat step e two more times to complete adding the remaining analysis systems. The layout of the analysis systems and interconnections in the Project Schematic should appear as shown below.

2. Assign materials. Accept Structural Steel (typically the default material) for the model. a. In the Steady-State Thermal schematic, right-click the Engineering Data cell and choose Edit…. The Engineering Data tab opens and displays Structural Steel as the default material. b. Click the Return to Project toolbar button. 3. Attach geometry. a. In the Steady-State Thermal schematic, right-click the Geometry cell, and then choose Import Geometry. b. Browse to open the file Rotor_Brake.agdb. This file is available on the ANSYS Customer Portal; go to http://support.ansys.com/training.

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Define the Cyclic Symmetry Model We now specify the cyclic symmetry for our quarter sector model (N = 4, 90 degrees) and prepare other general aspects of modeling in the Mechanical application. To setup a cyclic symmetry analysis, Mechanical uses a Cyclic Region object. This object requires selection of the sector boundaries, together with a cylindrical coordinate system whose Z axis is colinear with the axis of symmetry, and whose Y axis distinguishes the low and high boundaries. 1. Enter the Mechanical Application and set unit systems. a. In the Steady-State Thermal schematic, right-click the Model cell, and then choose Edit…. The Mechanical Application opens and displays the model. b. From the Menu bar , choose Units> Metric (mm, kg, N, s, mV, mA) . 2. Define the Coordinate System to specify the axis of symmetry. a. Right-click Coordinate Systems in the tree and choose Insert> Coordinate System. b. In the Details view of the newly-created Coordinate System, set Type to Cylindrical and Define By to Global Coordinates. 3. Define the Cyclic Region object. a. Right-click Model in the tree and choose Insert> Symmetry. b. Right-click Symmetry and choose Insert> Cyclic Region. The direction of the Y-axis should be compatible with the selection of low and high boundaries. The low boundary is designated as the one with a lower value of Y or azimuth. c. Select the three faces that have lower azimuth for the low boundary. These faces are highlighted in blue in the figure below. d. Select the three matching faces on the opposite end of the sector for the high boundary. These faces are highlighted in red in the figure below

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Cyclic Symmetry Analysis of a Rotor — Brake Assembly

4. Define Connections. Frictional contact exists between the rotor and brake pad, whereas bonded contact exists between the wall and the rotor. a. Expand the Connections folder in the tree, then expand the Contacts folder. Within the Contacts folder, two contact regions were detected automatically and displayed as Contact Region and Contact Region 2. b. Right-click the Contacts folder and choose Renamed Based on Definition. The contact region names automatically change to Bonded — Pad to Rotor and Bonded — Blade to Wall respectively. c. Highlight Bonded — Pad to Rotor and in the Details view, set Type to Frictional. Note that the name of the object changes accordingly. d. In the Friction Coefficient field, type 0.2 and press Enter.

Note For higher values of contact friction coefficient a damped modal analysis would be needed. At a level of 0.2 damping effects are being neglected.

Generate the Mesh In the following section we’ll use mesh controls to obtain a mesh of regular hexahedral elements. The Cyclic Region object will guarantee that matching meshes are generated on the low and high boundaries of the cyclic sector. Taking advantage of the shape and dimensions of the model, Named Selections will be used to choose the edge selections for each mesh control. Mesh control: Element Size on Pad-Wall-Rotor: Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Tutorials 1. Create a Named Selection for this Mesh Control. a. Right-click on Model and choose Insert> Named Selection. b. Highlight the Selection object, and set Scoping Method to Worksheet. c. Program the Worksheet, as shown below, to select the edges at 90 degrees of azimuth in the cylindrical coordinate system, keeping those in the z-axis range [1mm, 6 mm] (to remove the thickness of the wall). To add rows to the Worksheet, right-click in the table and select the option from the flyout menus. d. Click the Generate button. You should see 11 edges. e. Rename the object to Edges for Wall Rotor Pad Sector Boundary. The selection should display as follows:.

Note It may be useful to undock the Worksheet window and tile it with the Geometry view as shown above.

2. Insert a Mesh Sizing control. a. Right-click on Mesh and choose Insert> Sizing. b. Set Scoping Method to Named Selection. c. Choose the named selection defined in the previous step. 1454

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Cyclic Symmetry Analysis of a Rotor — Brake Assembly d. Set its Element Size to 0.5 mm. e. Set Behavior to Soft. Mesh control: Number of Divisions on Pad-Rotor: 1. Create a Named Selection to pick the circular edges in the orifice of the pad and rotor. This Named Selection will pick the circular edges in the orifice of the pad and rotor, which is within a radius of 5 mm. a. Right-click on Model and choose Insert> Named Selection. b. Highlight the Selection object, and set Scoping Method to Worksheet. c. Rename the object to Edges for Rotor Pad Orifice. d. Program the Worksheet, as shown below.

e. Click the Generate button. You should see 4 edges. 2. Insert a Mesh Sizing Control as before to select this Named Selection. a. Right-click on Mesh and choose Insert> Sizing. b. Set Scoping Method to Named Selection. c. Choose the named selection defined in the previous step. d. Set its Type to Number of Divisions and specify 9. e. Set Behavior to Hard. Mesh control: Element Size on Wall-Blade 1. Create a Named Selection object to pick the thicknesses of the Wall and Blade. a. Right-click on Model and choose Insert> Named Selection. b. Highlight the Selection object, and set Scoping Method to Worksheet. c. Rename the object to Edges for Wall Blade Thicknesses. d. Program the Worksheet as shown below.

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e. Click the Generate button. You should see 16 edges. 2. Insert a Mesh Sizing Control as before to select this Named Selection. a. Right-click on Mesh and choose Insert> Sizing. b. Set Scoping Method to Named Selection. c. Choose the named selection defined in the previous step. d. Set its Element Size to 1 mm. e. Set Behavior to Hard. Mesh Control: Number of Divisions on Blade — Longer Edges 1. Create a Named Selection object to pick the longer edges of the Blade. a. Right-click on Model and choose Insert> Named Selection. b. Highlight the Selection object, and set Scoping Method to Worksheet. c. Rename the object to Edges for Blade. d. Program the Worksheet as shown below.

e. Click the Generate button. You should see 2 edges. 2. Insert a Mesh Sizing Control as before to select this Named Selection. a. Right-click on Mesh and choose Insert> Sizing. b. Set Scoping Method to Named Selection. c. Choose the named selection defined in the previous step. d. Set its Type to Number of Divisions and specify 14. e. Set Behavior to Hard. Mesh Control: Number of Divisions on Blade — Shorter Edges

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Cyclic Symmetry Analysis of a Rotor — Brake Assembly 1. Create a Named Selection object to pick the shorter edges of the Blade. a. Right-click on Model and choose Insert> Named Selection. b. Highlight the Selection object, and set Scoping Method to Worksheet. c. Rename the object to Edges for Blade 2. d. Program the Worksheet as shown below.

e. Click the Generate button. You should see 2 edges. 2. Insert a Mesh Sizing Control as before to select this Named Selection. a. Right-click on Mesh and choose Insert> Sizing. b. Set Scoping Method to Named Selection. c. Choose the named selection defined in the previous step. d. Set its Type to Number of Divisions and specify 1. e. Set Behavior to Hard. Mesh Control: Method on Pad-Rotor-Wall-Blade 1. Insert a Sweep Method control. a. Right-click Mesh in the tree and choose Insert> Method. b. Select all the bodies by choosing Edit> Select All from the toolbar, then click the Apply button. c. In the Details view, set Method to Sweep. d. Set Free Face Mesh Type to All Quad. Generate the Mesh • For convenience, select all 6 mesh controls defined, right-click and choose Rename Based on Definition. • Right-click Mesh in the tree and choose Generate Mesh. The mesh should appear as shown below:

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Steady-State Thermal Analysis We now proceed to define the boundary conditions for a thermal analysis featuring cyclic symmetry. Thermal boundary conditions are prescribed throughout the model while steering clear of the faces comprising the sector boundaries since temperature constraints are already implied there. 1. Define a convection interface. a. Right-click Steady-State Thermal in the tree and choose Insert> Convection. b. Select the outer faces of the Wall and the Blade as shown in the figure (8 faces).

c. Specify a Film Coefficient of air by right-clicking on the property and choosing Import Temperature Dependent upon which you choose Stagnant Air — Simplified Case. 2. Insulate the upper and lower faces of the Wall. • Select the upper and lower faces of the Wall, then right-click and choose Insert> Perfectly Insulated. 3. Apply a temperature load to the Pad and Rotor.

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Cyclic Symmetry Analysis of a Rotor — Brake Assembly a. Select the remaining faces on the assembly on the Pad and the Rotor, then right-click and choose Insert> Temperature. Exclude any faces on the sector boundaries or in the frictional contact. b. Type 100°C as the Magnitude and press Enter. 4. Solve and review the temperature distribution. a. Right-click Solution under Steady-State Thermal and choose Insert> Thermal> Temperature. b. Solve the steady-state thermal analysis. c. Review the temperature result by highlighting the Temperature result object.

Note Although insignificant in this model, temperature variations and their effect on the structural material properties are generally important to the formulation of physically accurate models.

Static Structural Analysis In this analysis, the brake is loaded onto the rotor in a single load step. The contact status is monitored at various stages of loading and three points are selected as pre-stress conditions for subsequent modal analyses. Because both contact and geometric nonlinearities are present, each pre-stress condition will present a different effective stiffness matrix to its corresponding modal analysis. The solver uses restart points, generated in the static analysis, to record the snapshot of the nonlinear tangent stiffness matrices and transfers them into the subsequent linear systems. This technique is referred to as Linear Perturbation.

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Tutorials 1. Apply the pressure and boundary conditions to engage the brake pad into the rotor. a. Select the bottom face of the Pad as shown below. Right-click the Static Structural object in the tree and choose Insert> Pressure. b. In the Details view, click the Magnitude flyout menu, choose Function, and specify: =time*time*4000, then press Enter. This represents a quadratic function reaching 4000 MPa by the end of the load step.

c. Set up the frictionless supports on the faces of Blade, Wall and Pad as shown below.

2. Configure the Analysis Settings. a. Set Auto Time Stepping to On. b. Set Define By to Substeps. c. Set Initial Substeps to 30. d. Set Minimum Substeps to 10. e. Set Maximum Substeps to 30. f.

Set Large Deflection to On to activate geometric nonlinearities.

g. To ensure that Restart Points are generated, under Restart Controls, set Generate Restart Points to Manual, and request to retain All Files for load steps and substeps. Maximum Points to Save should also be set to All. 3. Proceed to solve the model using the standard procedure.

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Cyclic Symmetry Analysis of a Rotor — Brake Assembly Reviewing the contact status changes during the course of the load application The contact status will change with increasing loads from Near, to Sliding, to Sticking. A status change from Near to Sliding reflects the engagement of contact impenetrability conditions (normal direction). A change from Sliding to Sticking, reflects additional engagement of contact friction conditions (tangential direction). This progression will generally reflect an increased effective stiffness in the tangent stiffness matrix, which can be illustrated by a Force-deflection curve:

To review the contact status, insert a Contact Tool in the Solution folder. To display only the contact results at the frictional contact, unselect Bonded — Wall To Blade in the Contact Tool Worksheet. Insert three different Contact Status results with display times at 0.03, 0.5 and 0.8 seconds, which should reveal the progression in contact status as shown below (from left to right):

The legend for these contact status plots is as follows: • Yellow — Near • Light Orange — Sliding • Dark Orange — Sticking

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Modal Analysis There are three modal analyses to study the effect of contact status and stress stiffening on the free vibration response of the structure. Each of these will be based on a different restart point in the static structural analysis. To see all available restart points, you can inspect the timeline graph displayed when the Analysis Settings object of the Static Structural analysis is selected after solving. Restart points are denoted as blue triangle marks atop the graph:

To select the restart point of interest, go to the Pre-Stress (Static Structural) object under each Modal Analysis. Make sure Pre-Stress Define By is set to Time and specify the time. The object will acknowledge the restart point in the Reported Loadstep, Reported Substep and Reported Time fields. Configure the Modal analyses as follows: • In Modal 1 set Pre-Stress Time to 0.033 seconds. • In Modal 2 set Pre-Stress Time to 0.5 seconds. • In Modal 3 set Pre-Stress Time to 0.8 seconds. Because the boundary conditions (that is, the frictionless supports) are automatically imported from the static analysis, we can proceed directly to solve.

Solving and Reviewing Modal Results We’ll monitor the lowest frequencies of vibration which belong to Harmonic Indices 0 (symmetric) and 2 (anti-symmetric). 1. Right-click on the Solution folder of each Modal analysis and choose Solve. 2. When the solutions complete, go to the Tabular Data window of each modal analysis. You can inspect the listing of modes and their frequencies. Because our structure has a symmetry of N=4, there will be three solutions, namely for Harmonic Indices 0, 1 and 2. 3. In the Tabular Data window of each modal analysis, select the two rows for Harmonic Index 0 — Mode 1 and Harmonic Index 2 — Mode 1. Right-click and choose Create Mode Shape Results. The image below shows this view for the first Modal analysis:

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Cyclic Symmetry Analysis of a Rotor — Brake Assembly

An interesting alternative to this view is to see the sorted frequency spectrum. You may review this by setting the X-Axis to Frequency on any of the Total Deformation results in each modal analysis:

At this point, each modal analysis should have two results for Total Deformation to inspect the first Mode of Harmonic Indices 0 and 2. Recall the meaning of Harmonic Index solutions and how they apply to the model. Harmonic Index 0 represents the constant offset in the discrete Fourier Series representation of the model and corresponds to equal values of every transformed quantity, for example, displacements in X, Y and Z directions, in consecutive sectors. Thus deformations that are axially positive in one sector will have the same axially positive value in the next. The following picture compiles, from left to right, the mode shapes for the Near, Sliding and Sticking status at Harmonic Index 0:

Notice how increased engagement of the frictional contact in the assembly has the effect of producing higher frequency vibrations. Also, the mode of vibration goes from being localized at the contact interface when the contact is Near, but is forced to distribute throughout the wall of the rotor as the contact sticks.

Note You may need to specify Auto Scale on the Results toolbar so the mode shapes are plotted as shown.

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Tutorials Harmonic Index 2 solutions correspond to N/2 for our sector (90 degrees or N = 4). This Harmonic Index, sometimes called the asymmetric term in the Fourier Series, represents alternation of quantities in consecutive sectors. A positive axial displacement at a node in one sector becomes negative in the next, a radially outward displacement in one sector will become inward in the next, and so on. The following are the results for the first mode of this Harmonic Index:

The lowest mode shows nearly independent vibration of the rotor relative to the blade. On the highest mode, sticking reduces this relative movement. For a continued discussion on post-processing for Cyclic Symmetry and especially on features for postprocessing degenerate Harmonic Indices (those between 0 and N/2), please see Reviewing Results for Cyclic Symmetry in a Modal Analysis in the Mechanical help. End of tutorial.

Using Finite Element Access to Resolve Overconstraint Problem Description This tutorial demonstrates the use of Finite Element (FE) types exposed in the Mechanical application by examining an analysis of a bracket assembly with contacts. This tutorial attempts to show the features related to FE types in the context of resolving an over-constraint issue in a Static Structural Analysis.

Features Demonstrated • Create Node-based Named Selections – Using Worksheet Criterion – Using Node Selection Tool • Scope FE (node-based) Boundary Conditions • Display FE Connections • Scope Results to FE Nodes

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Using Finite Element Access to Resolve Overconstraint

Setting Up the Analysis System 1. Create Static Structural Analysis. a. Open ANSYS Workbench. b. On the Workbench Project page, drag a Static Structural system from the Toolbox to the Project Schematic. The Project Schematic should appear as follows:

2. Assign Materials. For this tutorial we will accept Structural Steel (typically the default material) for the model and add Aluminum Alloy as a material option. a. In the Static Structural schematic, right-click the Engineering Data cell and select Edit. The Engineering Data tab opens and displays Structural Steel as the default material.

b. Right-click the box below Structural Steel, where it says «Click here to add new material» and select Engineering Data Sources.

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c. Select the General Materials check box and then click the Add button for Aluminum Alloy. A book icon appears in the column next to the Add button (plus symbol) to indicate that the material is selected.

d. Click the Return to Project toolbar button to return to the Project Schematic.

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Using Finite Element Access to Resolve Overconstraint

3. Attach Geometry. a. In the Static Structural schematic, right-click the Geometry cell and choose Import Geometry>Browse.

b. Browse to the proper location and open the file Bracket_Assembly.agdb. This file is available in the ANSYS Customer Portal, go to http://support.ansys.com/training.

Define the Model 1. Launch Mechanical by right-clicking the Model cell and then choosing Edit. (Tip: You can also doubleclick the cell to launch Mechanical).

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Tutorials 2. Define Unit System: from the Menu bar , select Units> Metric (mm, kg, N, s, mV, mA). 3. Define Part Material and Create Named Selection. a. For this model, all of the parts have been defined as Structural Steel. However, we want to change the Material type of the Clevis to Aluminum Alloy. To do this, first expand the Geometry object in the tree. b. Select the Clevis object under Geometry. In the Details under the Material category, click the Structural Steel option in the Assignment field to display the drop-down list. Change the material to Aluminum Alloy.

c. Right-click on Clevis and select Create Named Selection. Enter the Selection Name «Clevis» and click the OK button.

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Using Finite Element Access to Resolve Overconstraint

The Selection Name window is shown below.

4. Define Connections. a. Expand the Connections folder in the tree, and then expand the Contacts folder. b. Right-click the Contacts folder and choose Renamed Based on Definition.

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Renaming is illustrated below.

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Using Finite Element Access to Resolve Overconstraint

Refine and Generate Mesh To be able to create and modify node-based boundary conditions, you must first generate the model’s mesh. In addition, for this example, we will use the Body Sizing feature to define certain local mesh sizing. 1. Insert Body Sizing. a. Right-click on the Mesh object and select Sizing.

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b. In the Details view, select the Scoping Method option in the Scope field and set it to Named Selection.

c. Select the Named Selection field and select Clevis from the drop-down menu. d. In the Element Size field, enter 4 (mm).

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Using Finite Element Access to Resolve Overconstraint

e. Right-click the Body Sizing object and select Rename Based on Definition.

As illustrated here, the object is renamed.

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2. Generate Mesh: Right-click on the Mesh object select Generate Mesh.

The completed mesh is shown here.

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Using Finite Element Access to Resolve Overconstraint

Static Structural Analysis At this time, we will specify the following boundary conditions: • Moment • Displacement • Fixed Support 1. Define Analysis Settings: Select the Analysis Settings object in the tree. In Details view change the Solver Controls>Large Deflection to On. This selection allows the solver to account for large deformation effects such as large deflection, large rotation, and large strain.

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2. Insert a Moment Load. a. Select the Static Structural object, right-click the mouse, and then choose Insert>Moment.

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Using Finite Element Access to Resolve Overconstraint

b. Select the inner face of the Clevis (1 Face) as illustrated here. In the Details for the Scope category, select the Geometry field and click Apply. Enter 1e5 N mm as the Magnitude and change the Behavior to Rigid.

3. Insert a Displacement and Fixed Support. a. With the Moment object still highlighted, right-click the mouse and select Insert>Displacement.

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b. Select the inner face of the circular hole highlighted here. Make sure that the model is oriented as shown (note the direction of the bolts) and then click the Apply button in the Geometry field. Set the values of X Component, Y Component, and Z Component, to 0 mm.

c. Finally, let’s immobilize the assembly by specifying Fixed Supports on the faces illustrated below. Under the Supports menu, select Fixed Support, select one of the faces, press and hold the Ctrl key, and then select the remaining three faces. Once all of the faces are selected, click the Apply button in the Geometry field.

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Using Finite Element Access to Resolve Overconstraint

Results and Solution This section outlines the steps to add result objects, solve your analysis, and review your results. 1. Specify Result Object and Solve. a. Highlight the Solution object, select the Deformation Menu on the Solution Context Toolbar, and select Total.

b. Right-click the Solution object and select Solve. 2. Review the Results. a. Select the Total Deformation object. The solved model should display as follows:

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The bulk of the result displays in blue, indicating no deformations on the assembly. This cannot be correct. In addition to that condition, the following Warning Messages display: • Large deformation effects are active which may have invalidated some of your applied supports such as displacement, cylindrical, frictionless, or compression only. Refer to Troubleshooting in the Help System for more details. • One or more MPC contact regions or remote boundary conditions may have conflicts with other applied boundary conditions or other contact regions. Refer to Troubleshooting in the Help System for more details. This second message indicates that one of the nodes is likely over-constrained. You can graphically display FE Connections from the Solution Information object, as illustrated below. In the Details, specify the Display control as CE Based and the Display Type as Lines. As you can see there is an abundance of Constraint Equations.

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Using Finite Element Access to Resolve Overconstraint

Using FE Types to Identify Over-Constraints Now, let’s look at Solver Output to track down the over-constraint issue. 1. Select the Solution Information object. The Worksheet displays. The contents of the Worksheet display output messages, including Warnings. Scroll through the messages, searching for over-constraint messages/warnings.

The warning highlighted here provides a starting point to correct the over-constraint. Node 390 is identified as a node that is over-constrained; specifically that it has multiple constraints on degree of freedom 3.

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Tutorials FE access makes it possible to select a single node using the Node ID. That is, Mechanical allows us to create a Named Selection that consists of Node 390 so we can that identify it specifically and view it graphically. 2. Select the Named Selections object and then click the Named Selection button on the toolbar. A Selection object is generated. In the Details for the Selection object, change the Scoping Method to Worksheet. The Worksheet view automatically displays.

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Using Finite Element Access to Resolve Overconstraint

3. Right-click in the first row of the table and select Add Row.

4. Specify the criteria as follows: • Entity Type = Mesh Node • Criterion = Node ID • Operator = Equal • Value = 390

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5. Click the Generate button. 6. Right-click on Selection and select Rename. Change the name to «Node 390». A selection is generated that is just the one node, Node 390, that is over-constrained. Select the Graphics tab to view the generated node.

7. With node-based Named Selections, it is possible to view the Constraint Equations (CEs) attached to a single node. Select Solution Information in the tree, select the Graphics tab at the bottom of the window, and then select Node 390 as the option for the control, Draw Connections Attached To. You should see the following illustration. The CEs are displayed as lines (note Display Type in the Details).

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Using Finite Element Access to Resolve Overconstraint

The Display Type specified as Points is illustrated below. You can see Node 390 as well as all of the other nodes used to calculate CEs. All nodes other than Node 390 are hollow. This indicates that each node is connected to Node 390. In addition, the Visible on Results control has been set to Yes. This facilitates the display of the contour results for the Total Deformation result and the CEs, also shown below.

Here is an illustration of the CEs while the Total Deformation object is selected.

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We have identified the over-constrained node, now, let’s correct the issue.

Using FE Type to Correct Over-Constraints A starting point to correct the over-constraint is to remove the Displacement at Node 390. But looking at the scoping of the Moment and Displacement, it is clear that they share the edge nodes on the hole on the side of the face where the Moment is applied. As a result, when the CE’s are generated from the Moment load, the solver tries to impose displacements on the edge nodes which may conflict with the Displacement already imposed due to the Displacement constraint. So, it is reasonable to try to remove the Displacement on the edge nodes. While a typical Displacement Boundary Condition does not allow for this option, it can be accomplished with Nodal Displacement. 1. Create Geometry-based Named Selection. a. Select the Named Selections object and then click the Named Selection button on the toolbar. A Selection object is generated. b. Make sure that the Face selection toolbar option is chosen and then select the hole in the Clevis. In the Details for the Selection object, the Scoping Method should be set to Geometry. In the Geometry field, click the Apply button to specify the hole as the Geometry. c. Right-click on Selection and select Rename. Change the name to «Hole Face».

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Using Finite Element Access to Resolve Overconstraint

2. Create Criterion-based Named Selection. a. Select the Named Selections object and then click the Named Selection button on the toolbar. A new Selection object is generated. b. Right-click on the new Selection object and select Rename. Change the name to «Hole Face Nodes». c. In the Details for the Selection object, change the Scoping Method to Worksheet. The Worksheet view automatically displays. d. Specify the criteria as illustrated here.

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Tutorials e. Take a moment to review and consider the criterion you have defined and then click the Generate button. 3. Convert Edge to Nodes and Remove it from the Geometry. Now, let’s use a criterion-based Named Selection to create a Named Selection for the hole that subtracts (removes) the nodes of the hole’s edge. a. Select the Named Selections object and then click the Named Selection button on the toolbar. A Selection object is generated. b. Make sure that the Edge selection option is chosen and then select the edge of the hole. In the Details for the Selection object, the Scoping Method should be set to Geometry. In the Geometry field, click the Apply button to specify the hole as the Geometry. c. Right-click on Selection and select Rename. Change the name to «Hole Edge».

d. Select the Named Selections object and then click the Named Selection button on the toolbar. A new Selection object is generated. e. Right-click on the new Selection object and select Rename. Change the name to «Hole Edge Nodes». 1488

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Using Finite Element Access to Resolve Overconstraint f.

In the Details for the Selection object, change the Scoping Method to Worksheet. The Worksheet view automatically displays. Specify the criteria as illustrated here and then click the Generate button.

One more Named Selection is required. This Named Selection will remove the edge nodes from the hole nodes. g. Select the Named Selections object and then click the Named Selection button on the toolbar. A new Selection object is generated. h. Right-click on the new Selection object and select Rename. Change the name to «Hole Face Minus Edge». i.

In the Details for the Selection object, change the Scoping Method to Worksheet. Specify the criteria as illustrated here and then click the Generate button.

We now have a node-based Named Selection that includes all of the nodes of the hole, minus the nodes of the inner edge of the hole. 4. Suppress the existing Displacement: select the Displacement object, right-click the mouse, and select Suppress. If desired, you could instead delete the load.

5. Create Nodal Displacement and Solve. Now let’s define the scope of the Nodal Displacement and resolve the analysis. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Tutorials a. Select the Static Structural object, click the Direct FE menu in the toolbar, and then select Nodal Displacement. b. Node-based boundary conditions can only be scoped to Named Selections. In the Details for the Nodal Displacement, specify Hole Face Minus Edge as the Named Selection and then specify each Component (X, Y, and Z) as 0.

c. Click the Solve button. The solution should appear as shown here.

The Constraint Equations should appear with a uniform pattern, as illustrated here for the Solution Information object. And once again, the Visible on Results control has been set to Yes so that you can view Constraint Equations and contour results (make sure to select the Graphics tab).

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Using Finite Element Access to Resolve Overconstraint

6. Examine Equivalent Stresses. Now, let’s examine the Equivalent Stresses on the model. a. Highlight the Solution object, right-click, and select Insert>Equivalent Stress. b. Right-click the mouse and select Evaluate Results. The result should appear as illustrated here.

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A zero Displacement was applied and this is reflected in the above result. c. Examine the stresses on the hole using direct node selection. i.

Graphically Select Nodes. Select the Mesh object and then open the Select Type (Geometry/Mesh) menu and choose Select Mesh.

ii. Open the Select Mode menu and choose Box Select.

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Using Finite Element Access to Resolve Overconstraint iii. Drag your cursor over the Clevis hole in a pattern similar to what is illustrated here to directly select the nodes in and around the hole.

iv. Right-click the mouse and select Named Selection. Enter «Stress Nodes» as the Selection Name.

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v. Select the Equivalent Stress object, right click the mouse and choose Clear Generated Data.

vi. Right-click the mouse and select Evaluate Results. Results can be scoped to FE-based Named Selections as illustrated here, where the Equivalent Stress result was scoped to the Named Selection Stress Nodes.

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Actuator Mechanism using Rigid Body Dynamics

End of tutorial.

Actuator Mechanism using Rigid Body Dynamics This example problem demonstrates the use of a Rigid Dynamic analysis to examine the kinematic behavior of an actuator after moment force is applied to the flywheel.

Features Demonstrated • Joints • Joint loads • Springs • Coordinate system definition • Body view • Joint probes

Setting Up the Analysis System 1. Create the analysis system. Start by creating a Rigid Dynamics analysis system and importing geometry. a. Start ANSYS Workbench. b. In the Workbench Project page, drag a Rigid Dynamics system from the Toolbox into the Project Schematic. c. Right-click the Geometry cell of the Rigid Dynamics system, and select Import Geometry>Browse.

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Tutorials d. Browse to open the Actuator.agdb file. A check mark appears next to the Geometry cell in the Project Schematic when the geometry is loaded. This file is available on the ANSYS Customer Portal; go to http://support.ansys.com/training. 2. Continue preparing the analysis in the Mechanical Application. a. In the Rigid Dynamics system schematic, right-click the Model cell, and select Edit. The Mechanical Application opens and displays the model.

The actuator mechanism model consists of four parts: (from left to right) the drive, link, actuator, and guide. b. From the Menu bar , select Units>Metric (mm, kg, N, s, mV, mA).

Note Stiffness behavior for all geometries are rigid by default.

3. Remove surface-to-surface contact. Rigid dynamic models use joints to describe the relationships between parts in an assembly. As such, the surface-to-surface contacts that were transferred from the geometry model are not needed in this case. To remove surface-to-surface contact: a. Expand the Connections branch in the Outline, then expand the Contacts branch. Highlight all of the contact regions in the Contacts branch. b. Right-click the highlighted contact regions, then select Delete. Note that this step is not needed if your Mechanical options are configured so that automatic contact detection is not performed upon attachment. 4. Define joints.

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Actuator Mechanism using Rigid Body Dynamics Joints will be defined in the model from left to right as shown below, using Body-Ground and Body-Body joints as needed to solve the model.

Prior to defining joints, it is useful to select the Body Views button in the Connections toolbar. The Body Views button splits the graphics window into three sections: the main window, the reference body window, and the mobile body window. Each window can be manipulated independently. This makes it easier to select desired regions on the model when scoping joints. To define joints: a. Select the drive pin face and link center hole face as shown below, then select Body-Body>Revolute in the Connections toolbar.

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b. Select the drive center hole face as shown below, then select Body-Ground>Revolute in the Connections toolbar.

c. Select the link face and actuator center hole face as shown below, then select Body-Body>Revolute in the Connections toolbar.

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Actuator Mechanism using Rigid Body Dynamics

d. Select the actuator face and the guide face as shown below, then select Body-Body>Translational in the Connections toolbar.

e. Select the guide top face as shown below, then select Body-Ground>Fixed in the Connections toolbar.

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5. Define joint coordinate systems. The coordinate systems for each new joint must be properly defined to ensure correct joint motion. Realign each joint coordinate system so that they match the corresponding systems pictured in step 4. To specify a joint coordinate system: a. In the Outline, highlight a joint in the Joints branch. b. In the joint Details view, click the Coordinate System field. The coordinate field becomes active. c. Click the axis you want to change (i.e., X, Y, or Z). All 6 directions become visible as shown below.

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Actuator Mechanism using Rigid Body Dynamics

d. Click the desired new axis to realign the joint coordinate system. e. Select Apply in the Details view once the desired alignment is achieved. 6. Define a local coordinate system. A local coordinate system must be created that will be used to define a spring that will be added to the actuator. a. Right-click the Coordinate Systems branch in the Outline, then select Insert>Coordinate System. b. Right-click the new coordinate system, then select Rename. Enter Spring_fix as the name. c. In the Spring_fix Details view, define the Origin fields using the values shown below:

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Tutorials 7. Add a spring to the actuator. a. Select the bottom face of the actuator as shown below, then select Body-Ground>Spring in the Connections toolbar.

b. In the Reference section of the spring Details view, set the Coordinate System to Spring_fix. c. In the Definition section of the spring Details view, specify: Longitudinal Stiffness = 0.005 N/mm Longitudinal Damping = 0.01 N*s/mm

8. Define analysis settings. To define the length of the analysis: a. Select the Analysis Settings branch in the Outline.

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Actuator Mechanism using Rigid Body Dynamics b. In the Analysis Settings Details view, specify Step End Time = 60. s 9. Define a joint load. A joint load must be defined to apply a kinematic driving condition to the joint object. To define a joint load: a. Right-click the Transient branch in the Outline, then select Insert>Joint Load. b. In the Joint Load Details view, specify: Joint = Revolute — Ground To Drive Type = Moment Magnitude = Tabular (Time) Graph and Tabular Data windows will appear. c. In the Tabular Data window, specify that Moment = 5000 at Time = 60, as shown below.

10. Prepare the solution a. Select Solution in the Outline, then select Deformation>Total in the Solution toolbar. b. In the Outline, click and drag the link to actuator revolute joint to the Solution branch. Joint Probe will appear under the Solution branch. This is a shortcut for creating a joint probe that is already scoped to the joint in question. Because we want to find the forces acting on this joint, the default settings in the details of the joint probe are used. c. Click the Solve button in the main toolbar. 11. Analyze the results a. After the solution is complete, select Total Deformation under the Solution branch in the Outline. A timeline animation of max/min deformation vs. time appears in the Graph window. b. In the Graph window, select the Distributed animation type button, and specify 100 frames and 4 seconds, as shown below. (These values have been chosen for efficiency purposes, but they can be adjusted to user preference.)

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c. Click the Play button to view the animation. d. Select the Joint Probe branch in the Outline, e. In the Joint Probe Details view, specify X Axis in the Result Selection field. f.

Right-click the Joint Probe branch, then select Evaluate All Results.

The results from the analysis show that the spring-based actuator is adding energy in to the system that is reducing the cycle time. End of tutorial.

Track Roller Mechanism using Point on Curve Joints and Rigid Body Dynamics This example problem demonstrates the use of a Rigid Dynamics analysis to examine the behavior of a track-roller mechanism using point on curve joints. In the example, the center point of an offset roller is placed directly onto a track edge to demonstrate the offset positioning capabilities of point on curve joints. While this model may not be entirely realistic, it clearly demonstrates the capabilities of the features highlighted.

Features Demonstrated • Point on curve joints • Reference coordinate system • Mobile coordinate system

Setting Up the Analysis System 1. Prepare the analysis system.

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Track Roller Mechanism using Point on Curve Joints and Rigid Body Dynamics a. Browse to open the file TrackRoller.mechdat. A Rigid Dynamics system will populate the Project Schematic. This file is available on the ANSYS Customer Portal; go to http://support.ansys.com/ training. b. Right click the Model cell, and select Edit to open the Mechanical Application. The model shown below will open.

2. Insert a new joint. In the Outline view, right-click the Connections node, then select Insert>Joint. 3. Define the new joint. a. Select the new joint in the Outline to display the joint Details view. b. In the Definition section of the Details view, click on the Connection Type field. The field becomes active. c. Select Body-Body from the Connection Type drop-down menu. d. Click the Type field. The field becomes active. e. Select Point on Curve from the Type drop-down menu. 4. Scope the new point on curve joint. a. Use the edge selection tool to select an edge of the track to be used as the curve in the new point on curve joint, as shown below.

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b. In the Details view, click to activate the Reference Scope field. c. Click Apply. d. Use the face selection tool to select a the face of the track to be used as the curve orientation surface, as shown below.

e. In the Details view, click to activate the Reference Curve Orientation Surface field. f.

Click Apply.

5. Define the reference coordinate system for the joint.

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Track Roller Mechanism using Point on Curve Joints and Rigid Body Dynamics a. In the Details view, click to activate the Reference Coordinate System field. b. Configure the orientation of the reference coordinate system so that Z is the normal of the curve orientation surface and X is in the tangent of the curve. The correct orientation is show below.

c. Click Apply. 6. Select and configure the point used in the point on curve joint. In this example, the center of the first roller (the circle selected below) will be selected as the point for the first joint. When creating a point on curve joint, the center of a selected geometric entity (i.e., a vertex, an edge, a surface, or a volume) is considered as the point. To specify a point: a. Use the edge selection tool to select the outer edge of the roller, as shown below.

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b. In the Details view of the joint, click to activate the Mobile Scope field. c. Click Apply. d. In the Details view, click to activate the Mobile Initial Position field. e. Select Override from the Initial Position drop-down menu. The Override option is necessary because the center point of the roller is offset from the track edge. If the Initial Position value of the mobile coordinate system is left to the default value, Unchanged, the reference coordinate system and mobile coordinate system are assumed to be coincident. 7. Define the mobile coordinate system for the joint. The center of the roller face will be used as the origin in this model. The orientations of the reference coordinate system and mobile coordinate system must be the same, or the point on curve joint will not work properly. To define the mobile coordinate system: a. In the joint Details view, click to activate the Mobile Coordinate System field. b. Select the edge of the roller using the edge selection tool. By default, this will configure the mobile coordinate system so that is corresponds to the reference coordinate system. c. Ensure that both coordinate systems align as shown below, then click Apply.

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Track Roller Mechanism using Point on Curve Joints and Rigid Body Dynamics

8. Create point of curve joint for the remaining rollers. Create three more point on curve joints, one for each additional roller, and define them in a similar manner as described in Step 3 through Step 7. Be sure to select a different roller edge (as described in Step 6) for each additional joint. The completed model and coordinate systems should be configured as shown in the model below.

9. Solve the model.

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Tutorials Click the Solve button. 10. Review the results. In the Outline view, select Total Deformation from the Solution node. The model displays with the point selected placed on the specified curve, as shown below.

End of tutorial.

Simple Pendulum using Rigid Dynamics and Nonlinear Bushing This tutorial demonstrates the use of a nonlinear bushing to modify the behavior of a simple pendulum.

Features Demonstrated • Nonlinear bushings • Reference coordinate system • Mobile coordinate system

Setting Up the Analysis System 1. Prepare the analysis system. a. Browse to open the file NLBushingTuto.wbpz. A Rigid Dynamics system will populate the Project Schematic. This file is available on the ANSYS Customer Portal; go to http://support.ansys.com/ training.

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Simple Pendulum using Rigid Dynamics and Nonlinear Bushing b. Right click the Model cell, and select Edit to open the Mechanical Application. The model shown below will open.

2. Continue preparing the analysis in the Mechanical Application. a. From the Menu bar , choose Units>Metric (mm, kg, N, s, mV, mA). b. From the Menu bar , choose Units>Degrees. 3. Insert a new bushing. a. In the Outline view, expand the Connections node, then select the Joints node. b. In the Connections toolbar, expand the Body-Body drop-down menu, and select Bushing.

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4. Scope the bushing to the correct faces: a. In the Outline view, select the new bushing to display the bushing Details View. b. In the Details View, click to activate the Reference Scoping Method field, then select Named Selection from the drop-down menu. c. Click to highlight the Reference Component field, then select FACE from the drop-down menu. d. In the Details View, click to activate the Mobile Scoping Method field, then select Named Selection from the drop-down menu. e. Click to highlight the Mobile Component field, then select FACE2 from the drop-down menu. The bushing reference coordinate system should now be defined as shown below:

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Simple Pendulum using Rigid Dynamics and Nonlinear Bushing

Note that the pendulum axis of rotation is the Z-axis. 5. Add a nonlinear rotational stiffness to the Z axis a. In the Outline View, highlight the new bushing, then toggle the Worksheet view. b. In the bushing worksheet, right-click the last diagonal term of the stiffness matrix, and select Tabular.

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Note that only the diagonal terms of the stiffness matrix can be defined as nonlinear. c. In the Tabular Data view, enter the angle and stiffness data pictured below:

The curve defined is displayed in the Graph View next to the table. 6. Solve the model. Click the Solve button. 7. Observe the defined nonlinear behavior. In the Outline View, select the Joint Probe under the Solution node to view the pendulum motion animation.

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Fracture Analysis of a Double Cantilever Beam (DCB) using Pre-Meshed Crack The pendulum should oscillate near its initial horizontal position due to the high stiffness entered for small angular displacements. With joint rotation unsuppressed, a 20° rotation of the pendulum will occur at the beginning of the analysis, and the pendulum should have free oscillation around the vertical axis.

End of tutorial.

Fracture Analysis of a Double Cantilever Beam (DCB) using Pre-Meshed Crack Problem Description The Double Cantilever Beam shown below is cracked at the center. This problem uses an imported model, already meshed, and then computes fracture parameters (energy release rates) using the Virtual Crack Close Technique (VCCT) on a static structural analysis to determine the impact of a catastrophic failure to the structure.

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Features Illustrated • Importing a meshed model using Finite Element Modeler. • Nodal named selections. • Coordinate systems. • Crack definition. • Fracture Results • Charting.

Procedure 1. Create a Finite Element Modeler (FEM) system. a. Start ANSYS Workbench. b. From the Toolbox, under Component System, drag a Finite Element Modeler system onto the Project Schematic. 2. Import the meshed model. Import a Mechanical APDL input file into Finite Modeler. a. In the Finite Element Modeler schematic, right-click the Model cell and select Add Input Mesh > Browse. b. In the Open dialog box, for Please select your model format, select Mechanical APDL Input (*.cdb). c. Browse to open the file 3d_vcct. This file is available on the ANSYS Customer Portal; go to http:// support.ansys.com/training. d. Right-click the Model cell and select Properties to view the assembly mesh file you imported. 3. Establish a static structural analysis. a. From the Toolbox, drag a Static Structural system onto the Project Schematic.

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Fracture Analysis of a Double Cantilever Beam (DCB) using Pre-Meshed Crack b. Drag the Model cell on the Finite Element Modeler schematic on to the Model cell of the Static Structural system. c. Right-click the Model cell on the Finite Element Modeler and select Update. d. Right-click the Model cell of the Static Structural system and select Refresh. 4. Continue preparing the analysis in the Mechanical Application. a. In the Static Structural schematic, right-click the Model cell, and then choose Edit. The Mechanical Application opens and displays the model. Note that the mesh is composed of linear elements, and VCCT is only applicable to linear elements b. For convenience, use the Rotate toolbar button to manipulate the model so it displays as shown below.

Note You can perform the same model manipulations by holding down the mouse wheel or middle button while dragging the mouse.

c. From the Menu bar , choose Units> Metric (m, kg, N, s, V, A) . 5. Create a nodal named selection. a. On the Graphics toolbar, select the Edge button to toggle Edge selection mode. b. On the Graphics Options toolbar, select the Wireframe button to toggle wireframe mode. c. In the Tree Outline, right-click Model and select Insert>Named Selection. d. In the Graphics window, select the crack front edge. e. In the Details pane, for Geometry, click Apply. The named selection is created for the selected edge. f.

In the Tree Outline, under Named Selections, right-click the new named selection and select Rename.

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Tutorials g. Enter crack_front as the name. h. Right-click the crack_front named selection and select Create Nodal Named Selection. i.

In the Tree Outline, under Named Selections, right-click the new named selection and select Rename.

j.

Enter crack_nodes as the name.

6. Create a coordinate system with a Y-axis aligned to crack normal. a. In the Details view, select Coordinate System. b. In the Graphics window, select the edge on the open side of the crack. c. Right-click and select Insert > Coordinate System. The origin of the coordinate system should be on the open side of the crack. d. In the Details view, for Geometry, click Apply. e. Under Principal Axis, for Axis, select Y. f.

For Define by, select Global Z Axis.

g. Leave all other values at their defaults. 7. Define the crack. a. Select the Model object in the Tree Outline. b. Insert a Fracture object into the Tree by right-clicking the Model object and selecting Insert > Fracture. c. Insert a Pre-Meshed Crack object into the Tree by right-clicking the Fracture object and selecting Insert > Pre-Meshed Crack. d. In the Details View, for Crack Front (Named Selection), select the crack_nodes nodal named selection. e. For Coordinate System, select the coordinate system you defined. f.

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Leave the Suppressed value set to No.

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Fracture Analysis of a Double Cantilever Beam (DCB) using Pre-Meshed Crack

8. Apply loads. a. In the Tree Outline, select Static Structural. b. Right-click and select Insert>Fixed Support, or from the Environment Context toolbar, select Supports > Fixed Support. c. In the Graphics toolbar, select the Face button. d. In the Graphics window, select the face on the closed side of the crack. e. In the Details view, for Geometry, click Apply. f.

Right-click and select Insert>Displacement, or from the Environment Context toolbar, select Supports > Displacement.

g. In the Graphics toolbar, select the Edge button. h. In the Graphics window, select the top edge on the open side of the crack. i.

In the Details view, for Geometry, click Apply.

j.

Select the Z Component and select Tabular.

k. In the second row (2), for Z[m], enter 5.e-003. l.

Right-click and select Insert>Displacement, or from the Environment Context toolbar, select Supports > Displacement.

m. In the Graphics window, select the bottom edge on the open side of the crack. n. In the Details view, for Geometry, click Apply. o. Select the Z Component and select Tabular. p. In the second row (2), for Z[m], enter -5.e-003. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Tutorials 9. Define results. a. In the Tree Outline, right-click on Solution and select Insert > Fracture Tool. b. In the Details view, for Crack Selection, select Pre-Meshed Crack. c. Right-click the Fracture Tool folder and select VCCT Results > VCCT (G1), or select the Fracture Tool folder and, from the Fracture Tool toolbar, select VCCT Results > VCCT (G1). d. Also add the VCCT (G2), VCCT (G3), and VCCT (GT) results. 10. Solve. a. In the Tree Outline, under Static Structural, select Analysis Settings. b. Under Solver Controls, set Fracture to On. c. Click Solve. 11. View results. a. Select each result and view the results in the Graphics window.

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Fracture Analysis of a Double Cantilever Beam (DCB) using Pre-Meshed Crack

12. View the Graph window for each result. The graph plots the distance of the crack front node from the origin and the energy release rate as it moves along the crack front. Since the load applied on the crack faces is tensile, the Mode I energy release rate ((VCCT (G1) ) ) dominates in this case. The VCCT(G2) and VCCT(G3) results are approximately zero. The total energy release rate (VCCT (GT) ) is approximately equivalent to VCCT(G1) You have completed the fracture analysis and accomplished the overall objective for this tutorial. End of tutorial.

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Fracture Analysis of an X-Joint Problem with Surface Flaw using Internally Generated Crack Mesh Problem Description In this problem, a semi-elliptical crack is inserted at the tubular joint of the structure. Then crack mesh is generated on the defined crack and fracture parameters based on Stress Intensity Factors (SIFS) are computed and post-processed.

Features Illustrated • Importing geometry • Nodal named selections. • Coordinate systems. • Crack definition. • Fracture Results. • Charting.

Procedure 1. Establish a static structural analysis. a. Start ANSYS Workbench. b. From the Toolbox, drag a Static Structural system onto the Project Schematic. 2. Import the model. a. In the Static Structural schematic, right-click the Geometry cell and select Import Geometry > Browse. b. Browse to open the file X_Joint.agdb. This file is available on the ANSYS Customer Portal; go to http://support.ansys.com/training. See the introductory Appendix B section for downloading instructions. 3. Prepare the analysis in the Mechanical Application. a. In the Static Structural schematic, right-click the Model cell, and then choose Edit. The Mechanical Application opens and displays the model. b. For convenience, use the Rotate toolbar button to manipulate the model so it displays as shown below.

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Fracture Analysis of an X-Joint Problem with Surface Flaw using Internally Generated Crack Mesh

Note You can perform the same model manipulations by holding down the mouse wheel or middle button while dragging the mouse.

4. Generate mesh. a. In the Tree Outline, right-click Mesh and select Insert>Method. b. In the Graphics window, select the body. c. In the Details view, for Geometry, click Apply. d. For Method, select Tetrahedrons. This method is required for crack mesh generation. e. In the Tree Outline, select the Mesh object. f.

In the Details view, under Sizing, set the Relevance Center to Fine.

g. On the Graphics toolbar, select the Face button to toggle Face selection mode. h. In the Tree Outline, right-click Mesh and select Insert>Sizing. i.

In the Graphics window, select the external filet.

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Tutorials

j.

In the Details view, for Geometry, click Apply.

k. For Element Size, enter 5e-3 m. l.

Right-click the Mesh object and select Generate Mesh.

5. Create a coordinate system. a. In the Details view, select Coordinate System. b. In the Graphics window, select the edge on the open side of the crack. c. Right-click and select Insert > Coordinate System, or from the Environment Context toolbar, select Coordinate Systems> Coordinate System. d. In the Graphics window, select the vertex lying at the center of the filet face.

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Fracture Analysis of an X-Joint Problem with Surface Flaw using Internally Generated Crack Mesh

e. In the Details view, for Geometry, click Apply. f.

Under Principal Axis, for Axis, select X.

g. For Define by, select Hit Point Normal. h. In the Graphics window, click at the origin location of the coordinate system. i.

In the Details view, for Hit Point Normal, click Apply.

6. Define the crack. a. Select the Model object in the Tree Outline. b. Insert a Fracture object into the Tree by right-clicking the Model object and selecting Insert > Fracture. c. Insert a Crack object into the Tree by right-clicking the Fracture object and selecting Insert > Crack. d. On the Graphics toolbar, select the Body button to toggle Body selection mode. e. In the Graphics window, select the body. f.

In the Details view, for Geometry, click Apply.

g. For Coordinate System, select the coordinate system you previously defined. h. In addition, set the following options in the Details view: Major Radius

18.4 mm

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Tutorials Minor Radius

9.5 mm

Largest Contour Radius 2 mm Circumferential Divisions

16

Crack Front Divisions

35

i.

In the Tree Outline, right-click the Fracture object and select Generate All Crack Meshes.

j.

Zoom in on the external filet to see the generated crack mesh.

7. Apply loads. a. From the Menu bar , choose Units> Metric (mm, kg, N, s, mV, mA). b. In the Tree Outline, select Static Structural. c. Right-click and select Insert>Pressure, or from the Environment Context toolbar, select Loads > Pressure. d. In the Graphics window, select the top face. e. In the Details view, for Geometry, click Apply. f.

For Magnitude, enter -1000 MPa. The negative value indicates the pressure direction is upward.

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Fracture Analysis of an X-Joint Problem with Surface Flaw using Internally Generated Crack Mesh

8. Solve. a. In the Tree Outline, under Static Structural, select Analysis Settings. b. Under Solver Controls, set Fracture to On. c. Click Solve. 9. Define results. a. In the Tree Outline, right-click on Solution and select Insert > Fracture Tool. b. In the Details view, for Crack Selection, select Crack. c. Right-click the Fracture Tool folder and select SIFS Results > SIFS (K2), or select the Fracture Tool folder and, from the Fracture Tool toolbar, select SIFS Results > SIFS (K2). d. Also add the SIFS (K3) results. e. In the Tree Outline, right-click the Fracture Tool object and select Evaluate All Results. 10. View results. a. Select each result and view the results in the Graphics window. b. View the Graph window for each result. The graph plots the stress intensity factors against the curvilinear abscissa of the crack front, starting from the origin extremity.

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Since the crack surface normal is nearly aligned with the tensile load, the Mode I stress intensity factor (SIFS [K1]) dominates in this case. The SIFS (K2) and SIFS (K3) results show that Mode II and Mode III slightly contribute. You have completed the fracture analysis and accomplished the overall objective for this tutorial. End of tutorial.

Fracture Analysis of a 2D Cracked Specimen using Pre-Meshed Crack Problem Description This tutorial illustrates a fracture analysis of a 2D cracked specimen under a tensile load. The crack is modeled at the geometry level and the appropriate mesh controls are already defined. The fracture parameters are post-processed using a J-Integral approach which supports plastic material behavior.

Features Illustrated • Restoring archive. • Engineering Data. • Nodal named selections. • Coordinate systems. • Crack definition.

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Fracture Analysis of a 2D Cracked Specimen using Pre-Meshed Crack • Fracture Results. • Charting.

Procedure 1. Restore the project archive. a. Start ANSYS Workbench. b. Select File > Restore Archive. c. Browse to open 2D Cracked Specimen.wbpz. This file is available on the ANSYS Customer Portal; go to http://support.ansys.com/training. d. Save the project in the desired directory. 2. Check the material properties in Engineering Data. a. In the Static Structural schematic, right-click the Engineering Data cell and choose Edit. The Engineering Data opens and displays the material windows. b. Select the Structural Steel material and, in the Properties window, select the Bilinear Isotropic Hardening law.

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Tutorials c. Click on Return to Project on the main toolbar to go back to the project schematic. 3. Prepare the analysis in the Mechanical Application. a. In the Static Structural schematic, right-click the Model cell, and then choose Edit. The Mechanical Application opens and displays the model. b. For convenience, use the Rotate and Zoom toolbar buttons to manipulate the model so it displays as shown below.

Note Geometry and mesh controls have already been defined in the project. The geometry consists of two parts that represent the two different sides of the crack.

4. Create Mesh Connections. a. Select the Connections object in the Tree Outline. b. Insert a Connection Group object into the Tree by right-clicking the Connections object and selecting Insert > Connection Group. c. Insert a Mesh Connection object into the Tree by right-clicking the Connection Group object and selecting Insert > Manual Mesh Connection. d. On the Graphics toolbar, select the Edge button to toggle Edge selection mode. e. In the Graphics window, select the edge in lower right-hand corner of the upper part. f.

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Fracture Analysis of a 2D Cracked Specimen using Pre-Meshed Crack g. In the Graphics window, select the corresponding edge belonging to the bottom part. h. In the Details view, for Slave Geometry, click Apply.

i.

Repeat the last five steps two times to connect the edges couples that correspond to the regions where the mesh needs to be connected.

5. Generate mesh. a. Select the Mesh object in the Tree Outline. Note that some mesh controls are already defined in the model. b. Right-click the Mesh object and select Generate Mesh.

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6. Create a coordinate system. a. In the Details view, select Coordinate System. b. Right-click and select Insert > Coordinate System, or from the Environment Context toolbar, select Coordinate Systems> Coordinate System. c. In the Graphics window, select the vertex in the middle of the left hand side of the structure. d. In the Details view, for Geometry, click Apply.

7. Create nodal named selections. a. On the Graphics toolbar, select the Vertex button to toggle Vertex selection mode. b. In the Tree Outline, right-click Model and select Insert>Named Selection. c. In the Graphics window, select the crack front extremity.

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Fracture Analysis of a 2D Cracked Specimen using Pre-Meshed Crack d. In the Details pane, for Geometry, click Apply. The named selection is created for the selected vertex. e. In the Tree Outline, under Named Selections, right-click the new named selection and select Rename. f.

Enter crack_front as the name.

g. Right-click the crack_front named selection and select Create Nodal Named Selection. h. In the Tree Outline, under Named Selections, right-click the new named selection and select Rename. i.

Enter crack_node as the name.

8. Define the crack. a. Insert a Pre-Meshed Crack object into the Tree by right-clicking the Fracture object and selecting Insert > Pre-Meshed Crack. b. In the Details View, for Crack Front (Named Selection), select the crack_node nodal named selection. c. For Coordinate System, select the coordinate system you previously defined. d. For Solution Contours, set the value to 10. e. Leave the Suppressed value set to No.

9. Apply loads. a. From the Menu bar , choose Units> Metric (mm, kg, N, s, mV, mA). b. In the Tree Outline, select Static Structural. c. Right-click and select Insert>Displacement, or from the Environment Context toolbar, select Supports > Displacement. d. In the Graphics toolbar, select the Edge button. e. In the Graphics window, select the bottom edge.

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Tutorials f.

In the Details view, for Geometry, click Apply.

g. Select the Y Component and select Tabular. h. In the Details view, change the Independent variable to X. i.

In the Tabular Data window, enter the evolution of Y Component against X coordinates: i.

In the first row (1), for Y[mm], enter 0.4.

ii. In the second row (2), for X[mm], enter 10 and for Y[mm], enter 0.48. j.

In the Details view, change the X-Axis to Time.

k. In the Tabular Data window, enter the evolution of scale against time: In the first row (1), for Scale, enter 0. l.

Repeat steps a through k to add an additional displacement: Selected Edge

Independent Variable X: Tabular Data

X-Axis Time: Tabular Data

Top edge

Evolution of Y Component against X coordinates

Evolution of scale against time:

• In the first row (1), for X[mm], enter 0 and for Y[mm], enter 0.7.

• In the first row (1), for Scale, enter 0.

• In the second row (2), for X[mm], enter 10 and for Y[mm], enter 0.57. m. In the Tree Outline, select Static Structural. n. Right-click and select Insert>Displacement, or from the Environment Context toolbar, select Supports > Displacement. o. On the Graphics toolbar, select the Vertex button to toggle Vertex selection mode. In the Graphics window, select the vertex in the middle of the right hand side of the specimen. p. In the Details view, for Geometry, click Apply. q. Select the X Component and select Tabular. r.

In the Details view, set X Component to 0.

10. Solve. a. In the Tree Outline, under Static Structural, select Analysis Settings. b. Under Step Controls, note that substeps have already been defined because due to the plastic law the resolution will be nonlinear. c. Under Solver Controls, set Fracture to On. d. Click Solve. 1534

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Fracture Analysis of a 2D Cracked Specimen using Pre-Meshed Crack 11. Define J Integral results. a. In the Tree Outline, right-click on Solution and select Insert > Fracture Tool. b. In the Details view, for Crack Selection, select Pre-Meshed Crack. c. Right-click the Fracture Tool folder and select J-Integral (JINT), or select the Fracture Tool folder and, from the Fracture Tool toolbar, select J-Integral (JINT). d. In the Tree Outline, right-click the Fracture Tool object and select Evaluate All Results. 12. View results. a. Select the Equivalent Plastic Strain Results.

The plasticity is localized around the crack tip which is required for J-Integral calculation. b. Select the J-Integral (JINT) result and view the results in the Graphics window.

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Tutorials c. View the Graph window and the tabular data for each result. The tabular data display the J-Integral results at the crack front node for each integration contour. Note that the results converge after several contour integrations. J-Integral results start converging when the integration contour is outside the plastic zone. You have completed the fracture analysis and accomplished the overall objective for this tutorial. End of tutorial.

Interface Delamination Analysis of Double Cantilever Beam Problem Description This tutorial demonstrates the use of Interface Delamination feature available in Mechanical by examining the displacement of two 2D parts on a double cantilever beam. This same problem is demonstrated in VM248. The following example is provided to demonstrate the steps to setup and analyze the same model using Mechanical. As illustrated below, a two dimensional beam has a length of 100mm and an initial crack of length of 30mm at the free end that is subjected to a maximum vertical displacement (Umax) at the top and bottom of the free end nodes. Two vertical displacements, one positive and one negative, are applied to determine the vertical reaction at the end point. The point of fracture is at the vertex of the crack and the interface edges.

This image illustrates the dimension of the model.

This tutorial also examines how to prepare the necessary materials and mesh controls that work in cooperation with the Interface Delamination feature.

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Interface Delamination Analysis of Double Cantilever Beam

Features Demonstrated • Engineering Data/Materials • Static Structural Analysis • Match Control • Interface Delamination

Procedure 1. Create static structural analysis. a. Open ANSYS Workbench. b. On the Workbench Project page, drag a Static Structural system from the Toolbox to the Project Schematic. The Project Schematic should appear as follows. The properties window does not display unless you have made the required selection; right-click a cell and select Properties.

Note The Interface Delamination feature is only available for Static Structural and Transient Structural analyses.

2. Assign materials. This analysis requires the creation of the proper materials using the Engineering Data feature of Workbench. We will define a new Orthotropic Elastic material for the model as well as a Cohesive Zone Bilinear material for the Interface Delamination feature. a. In the Static Structural schematic, right-click the Engineering Data cell and choose Edit. The Engineering Data tab opens and displays Structural Steel as the default material. b. Click the box labeled «Click here to add new material» and enter the name «Interface Body Material».

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Tutorials c. Expand the Linear Elastic option in the Toolbox and right-click Orthotropic Elasticity. Select Include Property. The required properties for the material are highlighted in yellow.

d. Define the new material by entering the following property values and units of measure into the corresponding fields. Property

Value

Unit

Young’s Modulus X Direction

1.353E+05

MPa

Young’s Modulus Y Direction

9000

MPa

Young’s Modulus Z Direction

9000

MPa

Poisson’s Ratio XY

0.24

na

Poisson’s Ratio YZ

0.46

na

Poisson’s Ratio XZ

0.24

na

Shear Modulus XY

5200

MPa

Shear Modulus YZ

0.0001

MPa

Shear Modulus XZ

0.0001

MPa

The properties for the material should appear as follows:

e. Click the box labeled «Click here to add new material» and enter the name “CZM Material”. This material will specify the formulation used to introduce the fracture mechanism (Cohesive Zone Material method).

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Interface Delamination Analysis of Double Cantilever Beam

f.

Expand the Cohesive Zone option in the Toolbox and right-click Exponential for Interface Delamination. Select Include Property. The required properties for the material are highlighted in yellow.

g. Define the new material by entering the following property values and units of measure into the corresponding fields. Property

Value

Maximum Normal Traction

2.5E+07 Pa

Normal Separation Across the Interface

4E-06

m

1

m

Shear Separation at Maximum Shear Traction

Unit

The properties for the material should appear as follows.

3. Attach geometry. a. In the Static Structural schematic, right-click the Geometry cell and select Import Geometry>Browse. b. Browse to the proper location and open the file 2D_Fracture_Geom.agdb. This file is available on the ANSYS Customer Portal; go to http://support.ansys.com/training. c. Right-click the Geometry cell and select Properties. In the Properties window, set the Analysis Type property to 2D. The Project Schematic should appear as follows:

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4. Launch Mechanical. Right-click the Model cell and then choose Edit. (Tip: You can also double-click the cell to launch Mechanical). 5. Define unit system. From the menu bar in Mechanical, select Units>Metric (mm, kg, N, s, mV, mA). 6. Define 2D behavior. a. Highlight the Geometry folder. b. In the Details pane, specify the 2D Behavior property as Plane Strain. This constrains all of the UZ degrees of freedom. See the 2D Analyses section for additional information about this property.

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Interface Delamination Analysis of Double Cantilever Beam 7. Apply Material: Expand the Geometry folder and select the Part 2 folder. Set the Assignment property to «Interface Body Material». Selecting the Part 2 folder allows you to assign the material to both parts at the same time.

8. Suppress Contact.

Caution Contact cannot be present for this analysis. a. Expand the Connections folder and then expand the Contacts folder. b. Right-click the Contact Region object and select Suppress.

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9. Define coordinate systems. This analysis requires a mesh Match Control property to match the elements of the two parts. To properly define the Match Control property, you need to define coordinate systems for the element faces that will be matched with one another. In theory, for this model, one coordinate system could facilitate the specification of the Mesh Match Control because the coordinate systems you are about to create are virtually identical. a. Right-click the Coordinate Systems object in the tree and select Insert>Coordinate System.

b. Right-click the new coordinate system object, select Rename, and name the object «High Coordinate System.» c. In the Details pane of the newly-created Coordinate System object, select the Geometry property field Click to Change.

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Interface Delamination Analysis of Double Cantilever Beam d. Select the Edge selection filter (on the Graphics Toolbar) and highlight an edge in the center of the model. This tutorial employs the Depth Picking tool because of the close proximity of the two edges involved in the interface, as well as the crack. As illustrated here, the graphics window displays a stack of rectangles in the lower left corner. The rectangles are stacked in appearance, with the topmost rectangle representing the visible (selected) geometry and subsequent rectangles representing additional geometry selections. For this example, the topmost geometry is the «high» edge.

e. Click Apply in the Geometry property. The «High Coordinate System» is defined. f.

Right-click the Coordinate Systems object again and insert another Coordinate System object. Rename this object «Low Coordinate System.»

g. Select the Edge selection filter and highlight an edge in the center of the model. Using the Depth Picking tool, select the second rectangle in the stack, and then scope the edge as the geometry (Apply in the Geometry property). This scoping is illustrated below.

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10. Define Mesh Options and Controls. a. Select the Mesh object. Define the following Mesh object properties: • Set Use Advanced Size Function (Sizing category) to Off • Enter an Element Size (Sizing category) of 0.750. • Set Element Midside Nodes (Advanced category) to Kept.

b. Right-click the Mesh object and select Insert>Match Control.

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Interface Delamination Analysis of Double Cantilever Beam

c. Activate the High Geometry Selection property by selecting its field (that is highlighted in yellow). The Apply and Cancel buttons display. Select the Edge selection tool and highlight one of the edges in the center of the model. Use the Depth Picking tool to select the topmost geometry. Click the Apply button.

d. Perform the same steps to specify the Low Geometry Selection property, as illustrated below.

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e. Change the Transformation property from Cyclic to Arbitrary and specify the High Coordinate System and Low Coordinate System properties using the coordinate systems created in the previous step of the tutorial. The object should appear as illustrated below.

f.

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Select the Edge selection filter (on the Graphics Toolbar) and, holding the Ctrl key, select the four side edges.

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Interface Delamination Analysis of Double Cantilever Beam

g. Right-click the Mesh object and select Insert>Sizing. This mesh sizing control should be scoped to the four side edges. h. In the Details view, enter 0.75 mm as the Element Size. i.

Select the Edge selection filter (on the Graphics Toolbar) and highlight an edge in the center of the model. Use the Depth Picking tool and, holding the Ctrl key, select both rectangles in the lower left corner of the graphics window. Continue to hold the Ctrl key, and select an edge of the crack. Again, use the Depth Picking tool and select both rectangles in the lower left corner of the graphics window. Still holding the Ctrl key, select the top and bottom edges on the model.

j.

Right-click the Mesh object and select Insert>Sizing. This mesh sizing control should be scoped to six (top and bottom and the four interface edges) edges.

k. In the Details view, enter 0.5 mm as the Element Size. l.

Right-click the Mesh object and select Generate Mesh.

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11. Define Interface Delamination object. a. Insert a Fracture folder into the tree by highlighting the Model object and selecting the Fracture button on the Model Context Toolbar. b. Select the Interface Delamination button on the Fracture Context Toolbar.

c. In the Details pane, set the Method property to CZM.

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Interface Delamination Analysis of Double Cantilever Beam

d. Set the Material property to CZM Material.

e. Select the Match Control that was created earlier in the tutorial for the Match Control property.

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The Interface Delamination object is complete.

12. Configure the Analysis Settings. a. Select the Analysis Settings object. b. Set the Auto Time Setting property to On and then enter 40 for the Initial Substeps, Minimum Substeps, and Maximum Substeps properties.

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Interface Delamination Analysis of Double Cantilever Beam

c. In the Details pane, set the Large Deflection property to On to activate geometric nonlinearities.

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Tutorials 13. Define boundary conditions. a. Select the Edge selection filter and select the two edges on the side of the model that is opposite of the crack. Select one edge, press the Ctrl key, and then select the next edge.

b. Highlight the Static Structural object, select the Supports menu on the Environment Context Toolbar, and then select Fixed Support.

c. Highlight the Static Structural object. With the Vertex selection filter active, select the vertex illustrated below, select the Supports menu, and then select Displacement.

d. Highlight the Displacement object in the tree and enter 10 (mm in the positive Y direction) as the loading value for the Y Component property. 1552

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Interface Delamination Analysis of Double Cantilever Beam

e. Create another Displacement. With the Vertex selection filter active, select the bottom vertex and then select Supports>Displacement. Enter -10 (mm in the negative Y direction) as the loading value for the Y Component property.

14. Specify result objects and solve. a. Highlight the Solution object, select the Deformation menu on the Solution Context Toolbar, and then select Directional Deformation. b. Under the Definition category in the Details view, set the Orientation property to Y Axis. c. Highlight the Solution object, select the Probe menu on the Solution Context Toolbar, and then select Force Reaction. d. Select Displacement for the Boundary Condition property. e. Click the Solve button.

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Tutorials 15. Review the results. Highlight the Directional Deformation and Force Reaction objects. Results appear as follows:

You may wish to validate results against those outlined in the verification test case (VM248). This is most easily accomplished by creating User Defined Results using the Worksheet. End of tutorial.

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Delamination Analysis using Contact Based Debonding Capability

Delamination Analysis using Contact Based Debonding Capability Problem Description This tutorial demonstrates the use of Contact Debonding feature available in Mechanical by examining the displacement of two 2D parts on a double cantilever beam. This same problem is demonstrated in VM255. The following example is provided to demonstrate the steps to setup and analyze the same model using Mechanical. As illustrated below, a two dimensional beam has a length of 100mm and an initial crack of length of 30mm at the free end that is subjected to a maximum vertical displacement (Umax) at the top and bottom of the free end nodes. Two vertical displacements, one positive and one negative, are applied to determine the vertical reaction at the end point. The point of fracture is at the vertex of the crack and the interface edges.

This tutorial also examines how to prepare the necessary materials that work in cooperation with the Contact Debonding feature.

Features Demonstrated • Engineering Data/Materials • Static Structural Analysis • Contact Regions • Contact Debonding

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Procedure 1. Create static structural analysis. a. Open ANSYS Workbench. b. On the Workbench Project page, drag a Static Structural system from the Toolbox to the Project Schematic. The Project Schematic should appear as follows. The properties window does not display unless you have made the required selection; right-click a cell and select Properties.

2. Define materials. a. In the Static Structural schematic, right-click the Engineering Data cell and choose Edit. The Engineering Data tab opens and displays Structural Steel as the default material. b. Click the box below the field labeled «Click here to add new material» and enter the name «Interface Body Material».

c. Expand the Linear Elastic option in the Toolbox and right-click Orthotropic Elasticity. Select Include Property. The required properties for the material are highlighted in yellow.

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Delamination Analysis using Contact Based Debonding Capability d. Define the new material by entering the following property values and units of measure into the corresponding fields. Property

Value

Unit

Young’s Modulus X Direction

1.353E+05

MPa

Young’s Modulus Y Direction

9000

MPa

Young’s Modulus Z Direction

9000

MPa

Poisson’s Ratio XY

0.24

NA

Poisson’s Ratio YZ

0.46

NA

Poisson’s Ratio XZ

0.24

NA

Shear Modulus XY

5200

MPa

Shear Modulus YZ

0.0001

MPa

Shear Modulus XZ

0.0001

MPa

Once complete, the properties for the material should appear as follows.

e. Now you need to create a new Material that specifies the formulation used to introduce the fracture mechanism. For this tutorial, the Cohesive Zone Material (CZM) method is used. Click the field labeled «Click here to add new material» and enter the name “CZM Crack Material”.

f.

Expand the Cohesive Zone option in the Toolbox and right-click Fracture-Energies based Debonding. Select Include Property. The required properties for the material are highlighted in yellow.

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g. Define the new material by entering the following property values and units of measure into the corresponding fields. Property Tangential Slip Under Normal Compression Maximum Normal Contact Stress

Value

Unit

No

NA

1.7E+06 Pa 280

J m^2

Maximum Equivalent Tangential Contact Stress

1E-30

Pa

Critical Fracture Energy for Tangential Slip

1E-30

J m^2

Artificial Damping Coefficient

1e-8

s

Critical Fracture Energy for Normal Separation

The properties for the material should appear as follows.

3. Attach geometry. a. In the Static Structural schematic, right-click the Geometry cell and choose Import Geometry>Browse. b. Browse to the proper location and open the file 2D_Fracture_Geom.agdb. This file is available on the ANSYS Customer Portal; go to http://support.ansys.com/training. c. Right-click the Geometry cell and select Properties. In the Properties window, set the Analysis Type property to 2D.

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Delamination Analysis using Contact Based Debonding Capability The Project Schematic should appear as follows:

4. Launch Mechanical. Right-click the Model cell and then choose Edit. (Tip: You can also double-click the cell to launch Mechanical). 5. Define unit system. From the menu bar in Mechanical, select Units>Metric (mm, kg, N, s, mV, mA). 6. Define 2D behavior. a. Select the Geometry folder. b. In the Details pane, set the 2D Behavior property to Plane Strain. This constrains all of the UZ degrees of freedom. See the 2D Analyses section for additional information about this property.

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7. Apply material. a. Expand the Geometry folder and select the Part 2 folder. b. In the Details pane, set the Assignment property to Interface Body Material. Selecting the Part folder allows you to assign the material to both parts at the same time.

8. Define contact region.

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Delamination Analysis using Contact Based Debonding Capability a. Expand the Connections folder and the Contacts folder. A Contact Region object was automatically generated for the entire interface of the two parts. b. Select the Edge selection filter (on the Graphics Toolbar) and highlight an edge in the center of the model. Using the Depth Picking tool, select the first rectangle in the stack, and then scope the edge as the geometry (Apply in the Contact property). This tutorial employs the Depth Picking tool because of the close proximity of the two edges involved in the interface. As illustrated here, the graphics window displays a stack of rectangles in the lower left corner. The rectangles are stacked in appearance, with the topmost rectangle representing the visible (selected) geometry and subsequent rectangles representing additional geometry selections. For this example, the topmost geometry is the «high» edge.

c. Select the Edge selection filter and highlight an edge in the center of the model. Using the Depth Picking tool, select the second rectangle in the stack, and then scope the edge as the geometry (Apply in the Target property). Verify that Bonded is selected as the contact Type and that Pure Penalty is set as the Formulation.

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d. Rename the contact «Body».

9. Define Mesh Options and Controls. a. Select the Mesh object. Define the following Mesh object properties: • Set Use Advanced Size Function (Sizing category) to Off. • Enter an Element Size (Sizing category) of 0.750. • Set Element Midside Nodes (Advanced category) to Kept. b. Right-click the Mesh object and select Insert>Sizing. This mesh sizing control should be scoped to the four side edges.

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Delamination Analysis using Contact Based Debonding Capability

c. In the Details view, enter 0.75 mm as the Element Size. d. Select the Edge selection filter (on the Graphics Toolbar) and highlight an edge in the center of the model. Use the Depth Picking tool and, holding the Ctrl key, select both rectangles in the lower left corner of the graphics window. Continue to hold the Ctrl key, and select an edge of the crack. Again, use the Depth Picking tool and select both rectangles in the lower left corner of the graphics window. Still holding the Ctrl key, select the top and bottom edges on the model.

e. Right-click the Mesh object and select Insert>Sizing. This mesh sizing control should be scoped to six (top and bottom and the four interface edges) edges.

f.

In the Details view, enter 0.5 mm as the Element Size.

g. Right-click the Mesh object and select Generate Mesh. 10. Specify Contact Debonding object. a. Insert a Fracture folder into the tree by highlighting the Model object and then selecting the Fracture button on the Model Context Toolbar. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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b. Right-click and select Insert>Contact Debonding. You could also select the Contact Debonding button on the Fracture Context Toolbar.

c. In the Details pane, set the Material property to CZM Crack Material.

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Delamination Analysis using Contact Based Debonding Capability

d. In the Details pane, set the Contact Region property to Body.

The Contact Debonding object is complete.

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11. Configure the Analysis Settings. a. Select the Analysis Settings object. b. Set the Auto Time Setting property to On and then enter 100 for the Initial Substeps, Minimum Substeps, and Maximum Substeps properties.

12. Apply boundary conditions. a. Select the Edge selection filter and select the two edges on the side of the model that is opposite of the crack. Select one edge, press the Ctrl key, and then select the next edge.

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Delamination Analysis using Contact Based Debonding Capability b. Highlight the Static Structural object, select the Supports menu on the Environment Context Toolbar, and then select Fixed Support.

c. Highlight the Static Structural object. With the Edge selection filter active, select the edge illustrated below, select the Supports menu and then select Displacement. In the Details pane, enter 10 (mm in the positive Y direction) as the loading value for the Y Component property.

d. Create another Displacement. With the Edge selection filter active, select the bottom edge, and then select Supports>Displacement. Enter -10 (mm in the negative Y direction) as the loading value for the Y Component property.

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13. Specify result objects and solve. a. Highlight the Solution object, select the Deformation menu on the Solution Context Toolbar, and then select Directional Deformation. b. Under the Definition category in the Details view, set the Orientation property to Y Axis. c. Highlight the Solution object, select the Probe menu on the Solution Context Toolbar, and then select Force Reaction. d. Select Displacement for the Boundary Condition property of the probe. e. Click the Solve button. 14. Review the results. Highlight the Directional Deformation and Force Reaction objects. Results appear as follows:

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Nonlinear Static Structural Analysis of a Rubber Boot Seal

You may wish to validate results against those outlined in the verification test case (VM255). This is most easily accomplished by creating User Defined Results using the Worksheet. End of tutorial.

Nonlinear Static Structural Analysis of a Rubber Boot Seal Problem Description This is the same problem demonstrated in the Mechanical APDL Technology Demonstration Guide. See Chapter 29: Nonlinear Analysis of a Rubber Boot Seal. The following example is provided only to demonstrate the steps to setup and analyze the same model using Mechanical.

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Tutorials This rubber boot seal example demonstrates geometric nonlinearities (large strain and large deformation), nonlinear material behavior (rubber), and changing status nonlinearities (contact). The objective of this example is to show the advantages of the surface-projection-based contact method and to determine the displacement behavior of the rubber boot seal, stress results. A rubber boot seal with half symmetry is considered for this analysis. There are three contact pairs defined; one is rigid-flexible contact between the rubber boot and cylindrical shaft, and the remaining two are self contact pairs on the inside and outside surfaces of the boot.

Features Demonstrated • Hyperelastic Material Creation • Remote Point • Named Selection • Manual Contact Generation • Large Deflection • Multiple Load Steps • Nodal Contacts

Setting Up the Analysis System 1. Create a Static Structural analysis system. a. Start ANSYS Workbench. b. On the Workbench Project page, drag a Static Structural system from the Toolbox to the Project Schematic.

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Nonlinear Static Structural Analysis of a Rubber Boot Seal

2. Create Materials. For this tutorial, we are going to create a material to use during the analysis. a. In the Static Structural schematic, right-click the Engineering Data cell and choose Edit. The Engineering Data tab opens. Structural Steel is the default material.

b. From the Engineering Data tab, place your cursor in the Click here to add new material field and then enter «Rubber Material».

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c. Expand the Hyperelastic Toolbox menu: i.

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Select the Neo-Hookean option, right-click, and select Include Property.

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Nonlinear Static Structural Analysis of a Rubber Boot Seal

ii. Enter 1.5 for the Initial Shear Modulus (µ) Value and then select MPa for the Unit. iii. Enter .026 for the Incompressibility Parameter D1 Value and then select MPa^-1 for the Unit.

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d. Click the Return to Project toolbar button to return to the Project Schematic. 3. Attach Geometry. a. In the Static Structural schematic, right-click the Geometry cell and choose Import Geometry>Browse.

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Nonlinear Static Structural Analysis of a Rubber Boot Seal

b. Browse to the proper folder location and open the file BootSeal_Cylinder.agdb. This file is available on the ANSYS Customer Portal; go to http://support.ansys.com/training.

Define the Model The steps to define the model in preparation for analysis are described below. You may wish to refer to the Modeling section of Chapter 29: Nonlinear Analysis of a Rubber Boot Seal in the Mechanical APDL Technology Demonstration Guide to see the steps taken in the Mechanical APDL Application. 1. Launch Mechanical by right-clicking the Model cell and then choosing Edit. (Tip: You can also doubleclick the Model cell to launch Mechanical). 2. Define Unit System: from the Menu bar , select Units> Metric (mm, kg, N, s, mV, mA). Also select Radians as the angular unit.

3. Define stiffness behavior and thickness: expand the Geometry folder and select the Surface Body object. Set the Stiffness Behavior to Rigid and enter a Thickness value of 0.01 mm.

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4. In the Geometry folder, select the Solid geometry object. In the Details under the Material category, open the Assignment property drop-down list and select Rubber Material.

5. Create a Cylindrical Coordinate System: Right-click the Coordinate Systems folder and select Insert>Coordinate System. Highlight the new Coordinate System object, right-click, and rename it to «Cylindrical Coordinate System». Specify properties of the Cylindrical Coordinate System: a. Under the Details view Definition category, change Type to Cylindrical and Coordinate System to Manual. b. Under the Origin group, change the Define By property to Global Coordinates.

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Nonlinear Static Structural Analysis of a Rubber Boot Seal c. Under Principal Axis select Z as the Axis value and set the Define By property to Global Y Axis. d. Under Orientation About Principal Axis, select X as the Axis value and select Global Z Axis for the Define By property.

6. Insert Remote Point: Right-click on the Model object and select Insert>Remote Point. 7. In Details view, scope the Geometry to cylinder’s exterior surface, set X Coordinate, Y Coordinate, and Z Coordinate to 0, and specify the Behavior as Rigid.

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8. Define Named Selections: a. Right-click on the Model object and select Insert>Named Selection. b. Select the exterior surface of the cylinder, Apply it as the Geometry, right-click, and Rename it to Cylinder_Outer_Surface.

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Nonlinear Static Structural Analysis of a Rubber Boot Seal

c. Right-click on the Surface Body object under the Geometry folder and select Hide Body. This step eases the selection of the boot’s inner surfaces.

d. Highlight the Named Selection object and select Insert>Named Selection. e. Select all of the inner faces of the boot seal as illustrated below and scope the faces as the Geometry selection. Make sure that the Geometry property indicates that 24 Faces are selected. Press the Ctrl key to select multiple surfaces individually or you can hold down the mouse button and methodically drag the cursor across all of the interior surfaces. Note that the status bar at the bottom of the graphics window displays the number of selected surfaces (highlighted in green in the following image).

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f.

Right-click the new Selection object and Rename it to Boot_Seal_Inner_Surfaces.

g. Again highlight the Named Selection object and select Insert>Named Selection. h. Reorient your model and select all of the outer faces of the boot seal as illustrated below and scope the faces as the Geometry selection. Make sure that the Geometry property indicates that 27 Faces are selected.

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Nonlinear Static Structural Analysis of a Rubber Boot Seal The selection process is the same. Press the Ctrl key to select multiple surfaces individually or you can hold down the mouse button and methodically drag the cursor across all of the surfaces (except the top surface of the boot).

i.

Right-click the new Selection object and Rename it to Boot_Seal_Outer_Surfaces.

9. Insert a Connection Group and Manual Contacts:

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Tutorials a. Highlight the Connections folder, right-click, and select Insert>Connections Group.

b. Right-click on the Connections Group and select Insert>Manual Contact Region. Notice that Connection Group is automatically renamed to Contacts and that the new contact region requires definition.

c. Create a Rigid-Flexible contact between the rubber boot and cylindrical shaft by defining the following Details view properties of the newly added Bonded-No Selection To No Selection. • Scoping Method set to Named Selections. • Contact set to Boot_Seal_Inner_Surfaces from drop-down list of Named Selections. • Target set to Cylinder_Outer_Surface from drop-down list of Named Selections. • Target Shell Face set to Top. • Type set to Frictional. • Frictional Coefficient Value equal to 0.2.

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Nonlinear Static Structural Analysis of a Rubber Boot Seal • Set Behavior set to Asymmetric. • Detection Method set to On Gauss Point. • Interface Treatment set to Add Offset, Ramped Effects.

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Note The name of the contact, Bonded-No Selection To No Selection, is automatically renamed to Frictional — Boot_Seal_Inner_Surfaces To Cylinder_Outer_Surface.

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Nonlinear Static Structural Analysis of a Rubber Boot Seal d. Right-click the Contacts folder object and select Insert>Manual Contact Region. Set Contact at inner surface of the boot seal. In details view of the newly added Bonded-No Selection To No Selection, change the following properties: • Scope set to Named Selection. • Contact and Target set to Boot_Seal_Inner_Surfaces. • Type set to Frictional. • Frictional Coefficient value equal to 0.2. • Detection Method set to Nodal-Projected Normal From Contact.

Note The Bonded-No Selection To No Selection is automatically renamed to Frictional — Boot_Seal_Inner_Surfaces To Boot_Seal_Inner_Surfaces.

e. Right-click the Contacts folder object and select Insert>Manual Contact Region. Set Contact at inner surface of the boot seal. Self Contact at outer surface of the boot seal. In details view of the newly added Bonded-No Selection To No Selection, specify the following properties: • Scoping Method set to Named Selection. • Contact and Target set to Boot_Seal_Outer_Surfaces. • Type set to Frictional.

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Tutorials • Frictional Coefficient Value equal to 0.2. • Detection Method set to Nodal-Projected Normal From Contact.

Note Bonded-No Selection To No Selection is automatically renamed to Frictional Boot_Seal_Outer_Surfaces To Boot_Seal_Outer_Surfaces.

Analysis Settings The problem is solved in three load steps, which include: • Initial interference between the cylinder and boot. • Vertical displacement of the cylinder (axial compression in the rubber boot). • Rotation of the cylinder (bending of the rubber boot). Load steps are specified through the properties of the Analysis Settings object. 1. Highlight the Analysis Settings object. 2. Define the following properties: • Number of Steps equals 3. • Auto Time Stepping set to On (from Program Controlled). • Define By set to Substeps. 1586

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Nonlinear Static Structural Analysis of a Rubber Boot Seal • Initial Substeps and Minimum Substeps set to 5. • Maximum Substeps set to 1000. • Large Deflection set to On.

3. For the second load step, define the properties as follows: • Current Step Number to 2. • Auto Time Stepping set to On (from Program Controlled). • Initial Substeps and Minimum Substeps set to 10. • Maximum Substeps set to 1000.

4. For the third load step, define the properties as follows: • Current Step Number to 3. • Auto Time Stepping set to On (from Program Controlled). • Initial Substeps and Minimum Substeps set to 20. • Maximum Substeps set to 1000.

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Boundary Conditions The model is constrained at the symmetry plane by restricting the out-of-plane rotation (in Cylindrical Coordinate System). The bottom portion of the rubber boot is restricted in axial (Y axis) and radial directions (in Cylindrical Coordinate System). 1. Highlight the Static Structural (A5) object and: • select the two faces (press the Ctrl key and then select each face) of the rubber boot seal as illustrated here. • right-click and select Insert>Displacement.

2. Set the Coordinate System property to Cylindrical Coordinate System and the Y Component property to 0.

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Nonlinear Static Structural Analysis of a Rubber Boot Seal

3. Highlight the Static Structural (A5) object and select the face illustrated here. Insert another Displacement and set the Y Component to 0 (Coordinate System should equal Global Coordinate System).

4. Insert another Displacement scoped as illustrated here and set the Coordinate System property to Cylindrical Coordinate System and the X Component property to 0.

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5. Insert a Remote Displacement from the Support drop-down menu on the Environment toolbar.

6. Specify Remote Point as the Scoping Method. 7. Select the Remote Point created earlier (only option) for the Remote Points property. 8. Change the X Component, Y Component, Z Component, Rotation X, Rotation Y, and Rotation Z properties to Tabular (Time) as illustrated below.

9. In the Tabular Data specify: • Y value for Step 2 and Step 3 as -10 mm.

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Nonlinear Static Structural Analysis of a Rubber Boot Seal • RZ value for Step 3 as 0.55 [rad].

Results and Solution 1. Highlight the Solution and then select Deformation>Total Deformation from the Solution toolbar.

2. Specify the Geometry as the boot body only, and set the Definition category property By as Time and the Display Time property as Last.

3. Highlight the Solution and then select Stress>Equivalent (von-Mises) from the Solution toolbar. 4. Specify the Geometry as the boot body only, and set the Definition category property By as Time and the Display Time property as Last.

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Tutorials 5. Highlight the Solution and then select Strain>Equivalent (von-Mises) from the Solution toolbar. 6. Specify the Geometry as the boot body only, and set the Definition category property By as Time and the Display Time property as Last.

7. Click the Solve button.

Note • The default mesh settings mesh keep mid-side nodes in elements creating SOLID186 elements (See Solution Information). You can drop mid-side nodes in Mesh Details view under the Advanced group. This allows you to mesh and solve faster with lower order elements. • Although very close, the mesh generated in this example may be slightly different than the one generated in the Chapter 29: Nonlinear Analysis of a Rubber Boot Seal in the Mechanical APDL Technology Demonstration Guide.

Review Results The solution objects should appear as illustrated below. You can ignore any warning messages. For a more detailed examination and explanation of the results, see the Results and Discussion section of Chapter 29: Nonlinear Analysis of a Rubber Boot Seal in the Mechanical APDL Technology Demonstration Guide. Total Deformation at Maximum Shaft Angle

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Nonlinear Static Structural Analysis of a Rubber Boot Seal

Equivalent Elastic Strain at Maximum Shaft Angle (at the end of 3 seconds)

Equivalent Stress (Von-Mises Stress) at Maximum Shaft Angle

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End of tutorial.

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Appendix C. Data Transfer Mesh Mapping To transfer data across a dissimilar mesh interface, the nodes of one mesh must be mapped to the local coordinates of a node/element in the other mesh. This section describes the settings that are available in Mechanical when data is mapped across two different meshes. You can add the exported mesh and loads as external data in the project schematic and couple a new Mechanical analysis system with this external data. The Mapping Settings described below are available within Mechanical for Thermal-Stress coupling with dissimilar mesh, Submodeling, when temperatures or displacements are transferred from Mechanical to Ansoft, or when the source data comes from an External Data system.

Mapping Settings • Mapping Control: By default, when Program Controlled is selected, the software will determine the appropriate algorithm and settings based on the source and target mesh data, as well as the data type being transferred. See Program Controlled Mapping for additional information. You may choose to modify the advanced features by setting this to Manual. • Mapping: A read-only field displaying that a «Profile Preserving» algorithm is being used. The following data is available for transfer: – Pressure – Heat Flux – Heat Generation – Temperature – Heat Transfer Coefficient – Thickness • Weighting: Choose which type of weighting should be performed. This option can be changed only if Mapping Control is set to Manual. – Triangulation creates temporary elements from the n closest source nodes to find the closest points that will contribute portions of their data values. For 3D, 4-node tetrahedrons are created, and for 2D, 3-node triangles are created by iterating over all possible combinations of the source points (maximum number controlled by the Limit property), starting with the closest points. If the target point is found within the element, weights are calculated based on the target’s location inside the element. – Distance Based Average uses the distance from the target node to the specified number of closest source node(s) to calculate a weighting value. – Shape Function loops over the source elements and tries to locate an element that each target node can be mapped to. Weights for each of the source nodes are then assigned based on the location of the target node and the shape function of the element. For each target node, the search efficiency can Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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Data Transfer Mesh Mapping be improved by restricting the search to a subset of the source elements. The search algorithm works by: 1. Distributing all source elements into Cartesian boxes or buckets. The number of buckets is controlled by the Scale property. 2. Locating each of the target nodes in a box. 3. Finding an element that each target node can be mapped to by restricting the search with each target’s box.

Note When there is a significant distance between target node and the closest element, e.g. Shell-Solid submodeling, the node and the element may not be found in the same box. In order to improve mapping accuracy in such cases, the Bucket Tolerance Option may be used. See Bucket Tolerance for more details.

– Kriging is a regression-based interpolation technique that assigns weights to surrounding source points according to their spatial covariance values. The algorithm combines the kriging model with a polynomial model to capture local and global deviations. The kriging model interpolates the source points based on their localized deviations, while the polynomial model globally approximates the source space. See Kriging Algorithms in the Design Exploration User’s Guide for more information.

Note By default, the Kriging technique uses an adaptive algorithm and ensures that the interpolated values do not exceed specific limits. The adaptive algorithm starts by using the higher-order Cross Quadratic polynomial to interpolate data. If the interpolated value of each target point is outside the extrapolation limit you specified, the algorithm reinterpolates data by reducing the polynomial order and the number of source points. Target nodes whose values are outside the limits when the lowest polynomial type is used are not assigned a value. The Kriging algorithm, when used with the higher-order Cross Quadratic or Pure Quadratic polynomial, may fail to correctly interpolate data for a target point if multiple source points are spaced close to one another or if the target point is outside the region enclosed by the source points that are selected for interpolation. This may introduce gross errors in the estimation of the target value and manifests itself mostly when mapping data on surface or edge geometries. In such cases, you should change the Polynomial Type to Constant or Linear and, if necessary, reduce the number of source points to be included for the interpolation.

– UV Mapping can be used to transfer data from one surface to another. Unlike other algorithms, UV mapping does not require the surfaces to be coincident. This allows for mapping between deformed and un-deformed geometries, as well as transfers between dissimilar geometry. Element data is required from both the source and the target mesh. If the source is an MAPDL CDB file containing volumetric element data, a nodal component must also be specified which will be used to define the surface from which the data transfer will occur.

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Polyhedral Surface Creation and Conversion to UV The first step in mapping in UV space is creating polyhedral surfaces from the given mesh data. If the source mesh is volumetric data, an associated nodal component must be selected such that the nodes consist of the surface area where the mapping is to occur. Once the source and target surfaces are created, they are then ‘unfolded’ and converted into UV coordinates. The UV space is defined as a parametric space where the axis data is from 0.0 to 1.0. The alignment points are used to anchor the nodal locations to the corners of the 1×1 box.

Interpolation Once the source and target data is converted to UV space, the target nodal UV locations are used to locate the source element that would contain the target node. The value for the target is then calculated based on the values provided from the source elements nodes. • Transfer Type: Enables you to choose the dimension of the transfer (for 3D transfers only). This option is available only for Triangulation, Shape Function, and for adaptive Kriging. For best results, use the Surface option when mapping data across surfaces and the Volumetric option when mapping data across volumes. When used with Triangulation: – The Surface option tries to map each target point by searching triangles that are created from the set of closest source points. The target point will be projected onto the plane relative to the triangle surface. If the point is found inside the triangle, the weights are calculated based on the target’s projected location inside the triangle. – The Volumetric option tries to map each target point by searching tetrahedrons that are created from the set of closest source points. When used with the Shape Function: – The Surface option uses the bucket surface search algorithm to locate a source element that each target node can be mapped to. This option supports only triangle and quadrilateral source elements; do not use it if your source is comprised of other element shapes as the algorithm does not account for these shapes. – The Volumetric option uses the bucket volume search algorithm to locate a source element that each target node can be mapped to. This option supports triangle, quadrilateral, tetrahedron, hexahedron, and wedge source elements. When used with adaptive Kriging, the Surface option uses fewer surrounding source points to interpolate data than the Volumetric option does. • 2D Projection: Available only for 2D to 3D data transfers from an External Data system connected to Mechanical. The default option is Normal To Plane. You will be able to choose between the default as well as all application and user input coordinate systems.

Rigid Transformation Controls Rigid transformation properties enable you to apply a coordinate transformation to the source points. Two options are available through the Mesh Alignment property:

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Data Transfer Mesh Mapping Use Origin and Euler Angles: The source locations are transformed by the coordinate system defined by the Origin and Theta entries. For example, applying a value of .1 meters to Origin X would modify the x locations of all the source points by adding .1 meters to their values. Use Coordinate Systems: To use this option, choose two coordinate systems, (1) Source Coordinate System attached to the source mesh frame of reference and (2) Target Coordinate System attached to the target mesh frame of reference. The transformations are automatically calculated such that the Source Coordinate System is aligned with the Target Coordinate System after transformation. For e.g. the source mesh is defined in the XY plane, whereas the target geometry is defined in a plane obtained by applying the Euler rotations RXY, RYZ and RZX to the XY plane. Then choosing Global Coordinate System as Source Coordinate System and the coordinate system created by applying the transformations RXY, RYZ and RZX to the Global Coordinate System as the Target Coordinate Systems, the source mesh is transformed such that it is aligned with the target geometry. This option is useful if the source points are defined with respect to a coordinate system that is not aligned with the target geometry system. The option Display Source Points on an Imported Load or Imported Thickness object inside Mechanical respects this transformation and can be very helpful in ensuring proper alignment between the source and target points.

Graphics Controls The following are graphics controls available: • Display Source Points: Toggle display of source point data. This can be helpful in visualizing where the source point data is in reference to the target mesh. • Display Source Point Ids: Toggle display of source point identifiers. This can be helpful in conjunction with validation objects when trying to identify nodes with undefined values. Note that if a column is not defined with the Node ID Data Type, the source point ids will correspond to the row from which they come in the file. For formatted and delimited files, ids will start after skipped lines. • Display Interior Points: Available when Display Source Points or Display Source Point Ids is set to On. Toggle allowing source point data to be displayed through the model so that interior points can be seen. • Display Projection Plane: Toggle display of project plane (available only for 2D to 3D mapping).

Legend Controls • Legend Range: Program Controlled (default) or Manual control of the legend minimum and maximum values. When Program Controlled is selected, the target data’s minimum and maximum values will be used in the legend. When Manual is selected, control of the Maximum and Minimum values can input and the graphics will be drawn based on these values. • Minimum: When Legend Range is set to Manual, this option is available for inputting the minimum legend value. • Maximum: When Legend Range is set to Manual, this option is available for inputting the maximum legend value. • Source Minimum: Read only field providing the source data minimum value. • Source Maximum: Read only field providing the source data maximum value.

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Advanced Advanced settings are filtered based on the Mapping Control and Weighting type selected in Mapping Settings (p. 1595). • Pinball: When finding the closest source points, a bounding box is created around the target point based on the value of the pinball. Any point outside of the bounding box will not be used. By default, the Program Controlled value is 0.0, which calculates the distance based on .05% of the source region’s bounding box size. The bounding box will automatically resize if the mapping is unable to find the minimum number of points required to calculate weighing factors. (Note that resizing occurs only for Program Controlled.) The Pinball option is not available when Weighting is set to Kriging or Shape Function.

Note In certain cases when Pinball is set to Program Controlled, the process of searching for source nodes around a target node can take a long time. In the image below, the target nodes are located on the red face. The target nodes (A) closest to the vertical body will quickly find nodes in the +Y axis direction. Target nodes (B) further down the X axis will take longer to find.

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Data Transfer Mesh Mapping

As an example, consider the case shown in the image below. The two red dots indicate target nodes in regions A and B. For each target node, the triangulation algorithm will begin its search for source nodes within the perimeter of a psuedo cube (bounding box) centered at its location. For the first pass, the edge length of the cube is set to be 0.05% of the maximum bounding box length of the source region. The algorithm looks to find ‘n’ source points (set by the limits property) in the positive and negative X, Y, and Z axes of the cube. If ‘n’ source points cannot be found in any of the six directions (±X, ±Y, and ±Z), the size of the search region is doubled and the process repeated. The search process continues until the required number of source points are found in all directions or until the search region extends beyond the limits of the source bounding box. During the first pass, for the target node in region A, the algorithm is able to find the required number of source nodes. However, for the target node in region B, sufficient nodes cannot be found in the +Y direction and the size of the search area is increased. As illustrated in the figure below, for the target node in region B, the algorithm runs through several iterations before it is able to find the required number of source nodes. This results

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in an increase in time as well as the possible inclusion of source nodes that are significantly further away from the target node.

Please note that for each target node the pinball is reset to its initial size (0.05% of the maximum bounding box length) before the search begins. For such cases it is recommended that you specify a pinball value so that the search box can be controlled to only find nodes within a certain region. This allows for triangulation to quickly search for source nodes, as well as to ignore source nodes that are sufficiently far away from the target node.

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• Limit: Number of nearby points considered for interpolation. Defaults to 20. Lower values will reduce processing time, however, some distorted or irregular meshes will require a higher Limit value to successfully encounter nodes for triangulation. When Weighting is set to Kriging, the minimum value that can be used is based on the selected Polynomial type. Weighting

Minimum Limit

Maximum Limit

Triangulation

5

20

Kriging (Constant)

3 (3D), 2 (2D)

Number of source points

Kriging (Linear)

4 (3D), 3 (2D)

Number of source points

Kriging (Pure Quadratic)

7 (3D), 5 (2D)

Number of source points

Kriging (Cross Quadratic)

10 (3D), 6 (2D)

Number of source points

• Outside Option: Enables you to ignore or choose a different weighting algorithm for target points that cannot be found within tetrahedrons/triangles when Triangulation is used. This option is available only for Triangulation. Defaults to Distance Based Average. – Distance Based Average: The mapping will use a weighted average based on distances to the closest Number of Points. – Ignore: Target points will be ignored and no value will be applied. – Projection: Triangles will be created from the closest Number of Points and the target point will be projected onto the plane relative to the triangle surface. If the point is found inside the triangle, the

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weights are calculated based on the target’s projected location inside the triangle. This option is available only for 3D transfers when the Transfer Type is set to Volumetric. • Number of Points: When Weighting is set to Distance Based Average, or when Outside Option is set to Distance Based Average or Projection, this option is available to specify how many closest source points should be used when calculating weights. Valid range is from 1 to 8 for Distance Based Average and 3 to 20 for Projection. Defaults to 3. • Outside Distance Checking: When Weighting is set to Triangulation and Outside Option is set to Distance Based Average or Projection, this option enables you to specify a Maximum Distance cutoff beyond which source points will be ignored. Defaults to Off. The maximum number of source points is limited to the value specified by the Number of Points setting. – If the Outside Option is set to Distance Based Average, only source points that lie on or within a sphere (centered at the targets location and radius defined by the Maximum Distance value) will provide contributions. – If the Outside Option is set to Projection, the algorithm only uses triangles with centroids that lie on or inside a sphere (centered at the targets location and radius defined by the Maximum Distance value). In Figure 33: Outside Nodes (Pink) with Mesh Overlay (p. 1603), all the pink nodes on the surface are found “Outside” the source points and will use the Outside Distance Checking based on the Maximum Distance specified. Figure 33: Outside Nodes (Pink) with Mesh Overlay

In Figure 34: Maximum Distance set to 0.005 (m) (p. 1604), the circle is at the mouse location with radius set to 0.005 (m). Nodes within this radius will be mapped. The source nodes are drawn as black dots and come from an extremely coarse mesh.

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Data Transfer Mesh Mapping Figure 34: Maximum Distance set to 0.005 (m)

In Figure 35: Mapped Nodes (p. 1604), the “Outside” nodes get mapped because they are located within the Maximum Distance. Figure 35: Mapped Nodes

The result of the import is shown in Figure 36: Imported Data using Maximum Distance for Outside Nodes (p. 1605). Transparent areas show target nodes that do not get mapped because there are no source nodes within the Maximum Distance.

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Figure 36: Imported Data using Maximum Distance for Outside Nodes

When Weighting is set to Kriging, this option allows you to ignore target points that lie outside the source bounding box. Defaults to Off. When this option is set to On, the Bounding Box Tolerance property enables you to include target points that lie outside the source bounding box by specifying a tolerance value. The algorithm adds this tolerance value to the source bounding box when it checks to see if a target point should be ignored or not. • Scale: When weighting is set to Shape Function, the scaling factor (%) determines the number of buckets used to distribute the source elements. Defaults to 50% (2 buckets). • Edge Tolerance: Dimensionless mapping tolerance (default = 0.05). – Shape Function for Surface/Edge topology. • Bucket Tolerance: When there is a significant distance between target node and the closest element, e.g. Shell-Solid submodeling, the node and the element may not be found in the same box. In order to improve mapping accuracy in such cases, the Bucket Tolerance Option may be used. When a Bucket Tolerance Value greater that 0 is specified, then a bounding region is created around the target node using the Bucket Tolerance Value and all the boxes associated with the region are used to find the appropriate element. To improve the mapping efficiency, the search is restricted only to the element within the bounding region. • Correlation Function: When weighting is set to Kriging, this property enables you to change the mathematical function that is used to model the spatial correlation between the sample points. Defaults to Gaussian. • Polynomial: When weighting is set to Kriging, this property enables you to change the mathematical function that is used to globally approximate the sample. Defaults to Adaptive. • Extrapolation Tolerance: You can use this option with adaptive Kriging to ensure that the interpolated value for each target point lies within specific limits. The tolerance is applied to the source range (based on the source points used for each target point) to determine if the interpolated value is satisfactory or if the data needs to be re-interpolated by reducing the polynomial order and the number of source points. For example, consider a target point having source values between 99 and 100. The default tolerance

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Data Transfer Mesh Mapping value of 10% will ensure that the mapped value is between 98.9 and 100.1. Target points whose values are outside the limits when the lowest polynomial type is used are not assigned a value.

Advanced Shell-Solid Advanced shell-solid settings are filtered based on the Mapping Control and Weighting type selected in Mapping Settings (p. 1595). They are only available for Shell-Solid submodeling. In the case of imported cut boundary conditions, Shape Function is the only available Weighting type. Bucket Tolerance Factor: This value is used to calculate the Bucket Tolerance Value for shell-solid submodeling. The Bucket Tolerance Value is calculated by scaling the maximum shell thickness with the Bucket Tolerance Factor. Figure 37: Shell-Solid Submodeling with Bucket Tolerance Factor = 1.0

Figure 38: Shell-Solid Submodeling with Bucket Tolerance Factor = 1.2

As shown in Figure 37: Shell-Solid Submodeling with Bucket Tolerance Factor = 1.0 (p. 1606) and Figure 38: Shell-Solid Submodeling with Bucket Tolerance Factor = 1.2 (p. 1606), the gap between the nodes

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in the filleted region is greater than the maximum shell thickness for the model. Hence using a Bucket Tolerance Factor equal to 1 results in nodes in the fillet not finding appropriate matching elements.(1) When Bucket Tolerance Factor of 1.2 is used, then additional buckets are included in the search resulting in better mapping results.(2)

Note Increasing the Bucket Tolerance Factor increases the number of buckets searched to find the matching element hence, may decrease the efficiency of the mapping. An appropriate value should be chosen so that the resulting bounding region includes the matching element but not too big so as to negatively affect the efficiency of the search. Shell Thickness Factor: For shell models with variable thickness, the gap between the target node, and matching element may be large. Shell Thickness Factor is used to exclude any matching element which has a gap greater than Thickness* Shell Thickness Factor. Thickness is the average element thickness of the matching element. Figure 39: Shell-Solid Submodeling with Shell Thickness Factor = 0.6

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Data Transfer Mesh Mapping Figure 40: Shell-Solid Submodeling with Shell Thickness Factor = 1.2

Note Increasing the Shell Thickness Factor to allow submodel nodes to be “found” can produce poor submodel results as shown in Figure 39: Shell-Solid Submodeling with Shell Thickness Factor = 0.6 (p. 1607) and Figure 40: Shell-Solid Submodeling with Shell Thickness Factor = 1.2 (p. 1608). where large Shell Thickness Factor causes the target nodes on the web region to be matched with the base (3), whereas the target nodes are more appropriately matched for a smaller Shell Thickness Factor (4).

Named Selection Creation These settings enable you to select whether Named Selections should be created for the following items: • Unmapped Nodes: Create a named selection containing all points that cannot be mapped. Defaults to Off. – Name: Field for the name that will be used when creating the named selection. Defaults to “Unmapped Nodes”. • Mapped Nodes: Create a named selection containing all mapped points. Defaults to Off. – Name: Field for the name that will be used when creating the named selection. Defaults to “Mapped Nodes”. • Outside Nodes: Create a named selection containing all the points that cannot be found within tetrahedrons/triangles when Triangulation is used. Defaults to Off. – Name: Field for the name that will be used when creating the named selection. Defaults to “Outside Nodes”.

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UV Source Controls/UV Target Controls • Alignment: Program Controlled (default) or Manual control of selecting the four alignment points needed for UV Mapping. The process of UV mapping involves aligning both the source and target nodal data from XYZ coordinates into the equivalent UV space. To do this, the mapper needs to have access to four alignment locations as reference points for unfolding and flattening the nodal information. These four locations are referred to as “Front Bottom”, “Rear Bottom”, “Rear Top”, and “Front Top”. When the Program Controlled alignment option is selected, the associated coordinate systems ZX plane is used in relation to the associated mesh nodal locations.

– Coordinate System: Available when Alignment is set to Program Controlled. One of the available coordinate systems must be selected as a reference point for Program Controlled alignment. The mesh nodal data is transformed related to the ZX plane of the selected coordinate system. A mean Z value is determined so that the nodes can be split into 2 groups, an upper and lower section. The nodes in each section are then sorted based on their X position. If there are nodes at the same X position, these points are then sorted based on their Z location. For the “Rear Bottom” and “Front Bottom” points, the minimum sorted Z point will be used, and for the “Rear Top” and “Front Top”, the maximum Z point will be used. – Nodes: Available when Alignment is set to Manual for UV Source Controls. The user must list the 4 node locations in the text entry separated by commas. The order must be input as Front Bottom, Rear Bottom, Rear Top, Front Top. – Target Front-Bottom, Target Rear-Bottom, Target Front-Top, Target Front-Top: Available when Alignment is set to Manual for UV Target Controls. The user must select geometric vertices for each alignment point.

Program Controlled Mapping When Program Controlled mode is selected, the software will use the following table to determine which type of mapping algorithm to use. Default settings will be used based on the properties described above. Source mesh can provide:

Target mesh can provide:

Weighting that will be used:

Nodes Only

Nodes Only

Uses Triangulation to calculate mapping data.

Nodes and Elements

Nodes Only

Uses Shape Function to calculate mapping data.

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Manual Mapping When manual mode is selected, you will be able to control advanced settings for the mapper. Based on the mesh data provided from the source and target, you will be able to choose the type of weighting algorithm. If the source mesh contains only points, you will be able to select from the following: • Triangulation • Distance Based Average • Kriging. If the source mesh also contains element data, you will have the items listed above as well as: • Shape Function Element shapes supported during mapping when Shape Function is selected: Element Shape

Supported

3 Node Triangle

X (2D) (3D)

6 Node Triangle

X (2D) (3D)

4 Node Quadrilateral

X (2D) (3D)

8 Node Quadrilateral

X (2D) (3D)

4 Node Tetrahedron

X (3D)

10 Node Tetrahedron

X (3D)

8 Node Hexahedron

X (3D)

20 Node Hexahedron

X (3D)

6 Node Wedge

X (3D)

15 Node Wedge

X (3D)

2D to 3D Mapping Mapping point data from 2D to 3D analyses is possible using the External Data system connected to a downstream Mechanical system. This mapping is performed by collapsing the 3D mesh data into a 2D plane and calculating target point weighting factors from the source point data. 2D results in the XY Plane:

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You will be able to select the 2D project plane to use based on the available coordinate systems as well as an option to select normal to the 2D source point data (Normal To Plane). Using the Graphics Controls described above, you will be able to turn on and off visualization of the source point data and the 2D projection plane. Source point and 2D projection plane displayed:

When selecting Cartesian coordinate systems, the projection will be done on the XY Plane. If the coordinate system is cylindrical, the projection will be rotated about the Z axis into the ZX Plane. Normal To Plane will project the target points into the source point plane. 3D mapped data using cylindrical coordinate system projection:

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3D mapped data using Normal To Plane:

Notes When mapping point cloud data, the mapping utility does not know where body boundaries are. If you have a model with contact between two bodies, the mapping may pick up points from both bodies causing undesired results.

Mapping Validation Mapping Validation objects can be inserted under imported data objects* to allow for an evaluation of how the mapping operation performed, by either right-clicking and selecting Insert > Validation from the context menu, or by clicking the Validation button in the toolbar. To perform a validation, 1612

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Mapping Validation right-click the Validation object and select Analyze. The following sections describe different methods to help analyze and determine if the mapping and interpolation that was performed produced an accurate representation of the mapped value data transferred from the source mesh onto the target mesh. *Mapping Validation is supported on the following analysis: • External Data Import • Submodeling – Not supported for Shell-Solid Submodeling • Thermal-Stress Analysis • One-way Acoustic Coupling Analysis

Definition The variable to display the validation information can be identified using the following properties: 1. File Identifier*: A list of variables obtained from the parent object will be listed in the File Identifier drop down. The validation information will be displayed based on the selected item. 2. Row: The row of the parent worksheet. 3. Data: The data type for the imported load. 4. Component: The vector component (X, Y, Z). 5. Complex Component: The real/imaginary component for complex loads. 6. Shell Face: Top/Bottom for loads applied to shells.

Note • File Identifier* property is only available for data imported through the External Data system. • Properties 2-6 are not available for data imported through the External Data system. Instead the validation information is displayed for the variable identified using the File Identifier property.

Settings Within the Settings category, the Type of validation must be specified by selecting Reverse Validation, Distance Based Average Comparison, or Source Value: • Reverse Validation. Reverse Validation takes the results of the imported data (based on the File Identifier) and maps these values back onto the source points. These newly mapped values are compared to the source variables original values. • Distance Based Average Comparison. Distance Based Average Comparison compares the results from the parent (based on the File Identifier) to mapped results obtained by using the distance-based average

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Data Transfer Mesh Mapping algorithm. Distance-based mapping will be done using the Number of Points specified. The output graphics will be displayed at the nodal locations of the target mesh. • Source Value. Source Value displays the selected File Identifier data values. With the Display In Parent turned On and the parent of the validation tree node item selected, the interpolated values calculated on the target mesh can easily be compared to the original source point values. • Undefined Points. Undefined Points displays the nodes which do not have an associated value based on the selected File Identifier. The Output Type can be set to Absolute or Relative Difference (default). For Relative Difference, the percent error is calculated and any values that are above 0.01% will be displayed in the graphics window. For Absolute Difference, any non-zero difference will be displayed. The Minimum and Maximum values will be displayed in the Statistics category of the details view. Subsets of the full set for either relative or absolute differences can be shown by adjusting the Display Minimum and Display Maximum fields. These fields must be within the Maximum and Minimum range defined within the Statistics category.

Graphics Controls There are multiple display options available: Scaled Spheres, Colored Spheres, Colored Diamonds, Colored Points, Contours, and Isolines. Colored Spheres and Scaled Spheres consume more memory and take longer to display on the screen due to the number of sides being drawn for each sphere. Colored Diamonds consume less memory and time, and Colored Points use the least amount. Contours and Isolines option will only be available when source mesh element connectivity is provided. Use External Data with an MAPDL CDB formatted file containing elements. All displays will be based on the range entered in the Display Minimum/Display Maximum fields. Display items that are colored will have a discrete legend displayed based on the Display Minimum and Display Maximum, divided equally into ranges. Scaled Spheres, Colored Spheres, and Colored Diamonds can be scaled based on the Scale field value. If the Display option is set to Isolines, a Line Thickness option will be available to control how the isolines are drawn. This setting will be respected when drawing isolines on the parent object when Display In Parent is On. If the Display In Parent property is set to On, the validation data will also be displayed when the parent object is selected. The validation data that is displayed in the parent object respects the Active Row and, if available, the Data/Component option selected in the details pane of the Imported Load object. • If the Component property in the details pane of the Imported Load object is set to All or Total, the displayed data represents the vector magnitude of the validation results corresponding to the source identifiers defined in the worksheet of the active row. • If the Component property is set to X, Y or Z component for vectors , the displayed data represents the validation results in the global X, Y or Z directions for the source identifiers defined in the worksheet of the active row. • If the Component property is set to XX/YY/ZZ/XY/YZ/ZX component for tensors, the displayed data represents the validation results in the global coordinate system for the source identifiers defined in the worksheet of the active row. • If the Data property is set to Temperature or Convection Coefficient, the displayed data represents the validation result for the corresponding source identifier selected in the worksheet of the active row.

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Mapping Validation Legend Divisions control how many contour colors to use and must be within the range from 3 to 14.

Statistics The Maximum and Minimum read-only fields show the full range of available results from the validation. Number Of Items shows how many items are currently being displayed in the graphics window. This number is based on the Display Minimum and Display Maximum values. Once a validation has been performed, the data can be exported to a file by simply right-clicking the Validation object and selecting Export.

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Appendix D. LS-DYNA Keywords Used in an Explicit Dynamics Analysis This appendix describes the following: Supported LS-DYNA Keywords LS-DYNA General Descriptions

Supported LS-DYNA Keywords The following gathers the supported keywords and their syntax for Explicit Dynamics (LS-DYNA Export) systems. The exported keyword file follows the same format as the corresponding Mechanical APDL application. Keywords conform to the “LS_DYNA Keyword User’s Manual” versions 970 and 971 (version 971 has particular features for the handling of beam cross section and integration options). Each keyword consists of one or more cards, each with one of more parameters. If a parameter is not shown, it will be assigned default values by the LS-DYNA solver. In addition some descriptions to Workbench features that do not relate directly to keywords are given at the end of this section, entitled General Descriptions.

*BOUNDARY_NON_REFLECTING Specifies impedance boundaries. Impedance boundaries can only be applied on solid elements in LSDYNA. Card • SSID = ID of segment on whose nodes the boundary is applied (see *SET_SEGMENT bellow). • AD = 0.0 (default) for setting the activation flag for dilatational waves to on. • AS = 0.0 (default) for setting the activation flag for shear waves to on.

*BOUNDARY_PRESCRIBED_MOTION_NODE_ID See *BOUNDARY_PRESCRIBED_MOTION_SET

*BOUNDARY_PRESCRIBED_MOTION_RIGID_ID See *BOUNDARY_PRESCRIBED_MOTION_SET

*BOUNDARY_PRESCRIBED_MOTION_SET_ID Specifies velocity and displacement boundary conditions. Card required for keyword option ID.

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LS-DYNA Keywords Used in an Explicit Dynamics Analysis • ID = ID of the prescribed motion keyword. This parameter is optional and does not have to be unique. An index number is added. • HEADING = Name of the specific boundary condition data. The name is taken from the caption of the applied velocity or displacement in the tree outline of the Mechanical application. Card1 • ID = ID of set of nodes or part (for rigid bodies) to which the boundary condition is applied. • DOF = 1, 2 or 3 depending whether the boundary condition is in the x, y or z direction respectively. Setting 4 is used if the boundary is applied according to a local coordinate system. • VAD = 0 or 2 depending whether the boundary condition is velocity or displacement. • LCID = ID of the curve prescribing the magnitude of the boundary condition. Constant values of velocity are applied as a step function from time = 0. Constant values of displacement are ramped from zero at time = 0 to the constant value at termination time. This is done to make sure that displacements are applied in a transient fashion. • SF = 1.0 (default) scale factor for load curve. • VID = 0 (default). ID of vector that defines the local coordinate system the boundary condition is applied with. • DEATH = 0.0 (default), sets it to 1E28. • BIRTH = 0, the motion is applied from the beginning of the solution. Card2: not required.

*BOUNDARY_SPC_SET Specifies Fixed Support, Simple Support and Fixed Rotation constraints. Card • NSID = ID of set of nodes to which the boundary is applied. • CID = ID of the associated coordinate system. 0 specifies the global coordinate system. • DOFX = 0 or 1 for free or fixed translation, respectively, along the x direction. It is set to 0 for Fixed Rotation and to 1 otherwise. • DOFY = 0 or 1 for free or fixed translation, respectively, along the y direction. It is set to 0 for Fixed Rotation and to 1 otherwise. • DOFZ = 0 or 1 for free or fixed translation, respectively, along the z direction. It is set to 0 for Fixed Rotation and to 1 otherwise. • DOFRX = 0 or 1 for free or fixed translation, respectively, along the x direction. It is set to 0 for Simple Support and to 1 otherwise. • DOFRY = 0 or 1 for free or fixed translation, respectively, along the y direction. It is set to 0 for Simple Support and to 1 otherwise.

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Supported LS-DYNA Keywords • DOFRZ = 0 or 1 for free or fixed translation, respectively, along the z direction. It is set to 0 for Simple Support and to 1 otherwise.

*CONSTRAINED_RIGID_BODIES Specifies rigid bodies to be merged into one part. The resulting Part ID matches the ID of the rigid body designated as the master. This keyword is created for rigid bodies which belong to the same multibody part. By constraining the rigid bodies together using a single multibody part you avoid specifying conflicting motion on the nodes shared among the rigid bodies. All boundary conditions applied to the master body will also be applied to all the slaves. Any boundary conditions that were applied to the slaves will be ignored. The body that is selected to be master is the first one that appears in the multibody-part list. Card • PIDM = ID of the master rigid body. • PIDS = ID of the slave rigid body.

*CONSTRAINED_SPOTWELD Specifies spot welds between non-contiguous nodal pairs of shell elements. This keyword is created when a spot weld contact is defined in the Mechanical application. Card • N1 = ID of the first node used in the weld. • N2 = ID of the second node present in the weld. • SN = Normal force at weld failure. • SS = Shear force at weld failure. • N = Exponent of normal force. • M = Exponent of shear force.

*CONTACT_AUTOMATIC_GENERAL Specifies friction or frictionless contacts between line bodies (beams). This keyword is created if the contact is specified using Body Interactions and the geometry contains line bodies. All the parameter cards are the same as in *CONTACT_AUTOMATIC_SINGLE_SURFACE.

*CONTACT_AUTOMATIC_NODES_TO_SURFACE Specifies nodes-to-surface friction or frictionless contacts. This keyword is created if the contact is specified using a Contact Region and the Behavior is set to Asymmetric. Card1 — mandatory • SSID = ID for the set of slave nodes involved in the contact. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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LS-DYNA Keywords Used in an Explicit Dynamics Analysis • MSID = ID for the set of master segments involved in the contact. • SSTYP = 4, the slave entities for the contact are nodes. • MSTYP = 0, the master entities for the contact are segments. • SBOXID, MBOXID, SPR and MPR are the same as in *CONTACT_AUTOMATIC_SINGLE_SURFACE. Parameter Card2 and Card3 is the same as in *CONTACT_AUTOMATIC_SINGLE_SURFACE.

*CONTACT_AUTOMATIC_SINGLE_SURFACE Specifies friction or frictionless contacts between parts. This keyword is created if the contact is specified using Body Interactions. Card1 — mandatory • SSID = ID for the set of parts created for the bodies in the Body Interaction. If the contact is applied to all the bodies in the geometry then this parameter is set to 0. • MSID = 0. • SSTYP =2, the slave entities are parts. If the contact is applied to all the bodies in the geometry then this parameter is set to 5. • MSTYP = 2, the master entities are parts. If the contact is applied to all the bodies in the geometry then this parameter is set to 0. • SBOXID = It is not used, will be left blank. • MBOXID = It is not used, will be left blank. • SPR = 1 (constant) requests that forces on the slave side of the contact be included in the results files NCFORC (ASCII) and INTFOR (binary). These two results files are not currently specified in the exported K file and are not created. The user will need to manually specify the *DATABASE_NCFORC and *DATABASE_BINARY_INTFOR keywords to obtain them. • MPR = 1 (constant) requests that forces on the master side of the contact be included in the results files NCFORC (ASCII) and INTFOR (binary). These two results files are not currently specified in the exported K file and are not created. The user will need to manually specify the *DATABASE_NCFORC and *DATABASE_BINARY_INTFOR keywords to obtain them. Card2 — mandatory • FS = Friction Coefficient value from the inputs for frictional contact. • FD = Dynamic Coefficient value from the inputs for frictional contact. • DC = Decay Constant value from the inputs for frictional contact. • VC = 0 (LS-DYNA default). • VDC = 10 (constant). This parameter specifies the percentage of the critical viscous damping coefficient to be used in order to avoid undesirable oscillation in the contact. Card3 — mandatory, left blank for defaults to be used. 1620

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Supported LS-DYNA Keywords Card A is the same as for *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE.

*CONTACT_AUTOMATIC_SURFACE_TO_SURFACE Defines specific surface-to-surface friction or frictionless contacts. This keyword is created if the contact is specified using a Contact Region and the Behavior is set to Symmetric. Card1 — mandatory • SSID = ID for the set of slave segments involved in the contact. • MSID = ID for the set of master segments involved in the contact. • SSTYP = 0, the slave entities for the contact are segments. • MSTYP = 0, the master entities for the contact are segments. • SBOXID, MBOXID, SPR and MPR are the same as in *CONTACT_AUTOMATIC_SINGLE_SURFACE. Parameter Card2 and Card3 are the same as in *CONTACT_AUTOMATIC_SINGLE_SURFACE. Card A • SOFT = 2 except for asymmetric contacts like NODES_TO_SURFACE and unbreakable bonded contacts for which it is set to 1. • SOFSCL = left blank, the default value of 0.1 will be used. This scale factor is used to determine the stiffness of the interface when SOFT is set to 1. For SOFT = 2 scale factor SLSFAC (see *CONTROL_CONTACT) is used instead. • LCIDAB = left blank. • MAXPAR= left blank. • SBOPT = 3. • DEPTH = 5.

*CONTACT_AUTOMATIC_SURFACE_TO_SURFACE_TIEBREAK Specifies breakable symmetric bonded contacts. This keyword is created for Bonded contact when the Breakable option is set to Stress Criteria and the contact Behavior is set to Symmetric. Card 1 is the same as in *CONTACT_TIED_SURFACE_TO_SURFACE_OFFSET. Card2 — mandatory • FS = Normal Stress Limit value for the bonded contact. • FD = Shear Stress Limit value for the bonded contact. • DC = 0 (LS-DYNA default). This parameter is not required for bonded contacts. • VC and VDC are the same as in *CONTACT_AUTOMATIC_SINGLE_SURFACE. Card3 — mandatory, is left blank. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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LS-DYNA Keywords Used in an Explicit Dynamics Analysis Card A is the same as for *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE.

*CONTACT_ONEWAY_AUTOMATIC_SURFACE_TO_SURFACE_TIEBREAK Specifies breakable asymmetric bonded contacts. This keyword is created for Bonded contact when the Breakable option is set to Stress Criteria and the contact Behavior is set to Asymmetric. Parameter cards are the same as in *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE_TIEBREAK. Card A is not used for this keyword.

*CONTACT_TIED_NODES_TO_SURFACE_OFFSET Specifies non breakable asymmetric bonded contacts. This keyword is created for Bonded contacts that are not designated as Breakable whose Behavior is set to Asymmetric. This keyword is not used for Body Interactions as these types of contacts are always symmetric. Card1 — mandatory • SSID = ID for the set of slave nodes involved in the contact. • MSID = ID for the set of master segment or for the set of parts involved in the contact. • SSTYP = 4. SSID indicates the ID for a set of nodes. • MSTYP = 0, MSID indicates the ID for a set of segments. • SBOXID, MBOXID, SPR and MPR are the same as in *CONTACT_AUTOMATIC_SINGLE_SURFACE. Card 2 left blank. Card 3 • SFS = left blank, the default value of 1.0 will be used. Default slave penalty stiffness scale factor for SLSFAC (see *CONTROL_CONTACT). • SFM= left blank, the default value of 1.0 will be used. Default master penalty stiffness scale factor for SLSFAC (see *CONTROL_CONTACT). • SST = the negative value of:

«Maximum Offset» is the Definition parameter available for bonded contacts and body interactions. «Maximum Offset» is obtained from the inputs of the Contact Region of Bonded type. • MST = SST.

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Supported LS-DYNA Keywords

*CONTACT_TIED_SURFACE_TO_SURFACE_OFFSET Specifies general non-breakable bonded contacts that are symmetric. This keyword is created for Bonded and non-breakable contacts which are defined by Contact Regions that are Bonded, non-breakable and whose Behavior is set to Symmetric. Card1 — mandatory • SSID = ID for a set of slave segments or a set of parts involved in the contact. • MSID = ID for the set of master segments or the set of parts involved in the contact. • SSTYP = specifies whether the ID used in SSID represents parts or segments. It is set to 0 if SSID represents a set of segments and 2 if it represents a set of parts. • MSTYP = SSTYP. • SBOXID, MBOXID, SPR and MPR are the same as in *CONTACT_AUTOMATIC_SINGLE_SURFACE. Cards 2 and 3 are the same as in *CONTACT_TIED_NODES_TO_SURFACE_OFFSET. Card A is the same as for *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE.

*CONTROL_ACCURACY Specifies control parameters that can improve the accuracy of the calculation. Card • OSU = 1. Global flag for objective stress updates. Required for parts that undergo large rotations. When set to 1 the flag is on. • INN = 4. Invariant node numbering for shell and solid elements. When set to 4 the flag is on for both shell and solid elements.

*CONTROL_BULK_VISCOSITY Sets the bulk viscosity coefficients globally. Card • Q1 = Quadratic Artificial Viscosity from the «Damping Controls» in the Analysis Settings. • Q2 = Linear Artificial Viscosity from the «Damping Controls» in the Analysis settings. • TYPE = -2. Internal energy dissipated by the viscosity in the shell elements is computed and included in the overall energy balance.

*CONTROL_CONTACT Specifies the defaults for computations of contact surfaces. Card 1

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LS-DYNA Keywords Used in an Explicit Dynamics Analysis • SLSFAC = 0 (default). Scale factor for sliding interface penalties. When set to 0 the value used is 0.1. This scale factor together with the SFS and SFM parameters of the individual contact keyword (see Card 3 of *CONTACT_TIED_NODES_TO_SURFACE_OFFSET) is used to determine the stiffness of the interface when SOFT is set to 2 (see Card A of *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE). • RWPNAL = 0 (there is no default value). Scale factor for rigid wall penalties. When equal to 0 the constrain method is used and nodal points which belong to rigid bodies are not considered. • ISLCHK = 1 (default). Initial penetration check in contact surfaces. When set to 1 there is no checking. • SHLTHK = 1 (default). Shell thickness considered in surface to surface and node to surface contact types. When set to 1, thickness is considered but rigid bodies are excluded. • PENOPT = 1 (default). Penalty stiffness value option. • THKCHG = 0 (default). • ORIEN = 2. Automatic reorientation for contact segments during initialization. When set to 2 it is active for manual (segment) and automated (part) input. • ENMASS = 0 if the Retain Inertia Of Eroded Material option of the Erosion Controls in the Details window of the analysis settings is set to No. = 2 (default) if Retain Inertia Of Eroded Material option of the Erosion Controls in the Details view of the analysis settings is set to Yes. This parameter regulates the treatment of the mass for eroded nodes in contact. When set to 0 eroding nodes are removed from the calculation. Card 2 • USRSTR = 0. Storage per contact interface for user supplied interface control subroutine. When set to 0 no input data is read and no interface storage is permitted in the user subroutine. • Default values are used for all other parameters. Card3 • SFRIC = 0. Default static coefficient of friction. • Default values are used for all other parameters. Card4 • IGNORE = 2. Specifies whether to ignore initial penetrations in the *CONTACT_AUTOMATIC options. When set to 2 initial penetrations are allowed to exist by tracking them. Also warning messages are printed with the original and the recommended coordinates of each slave node. • FRCENG = 0 (default). • SKIPRWG = 0 (default). • OUTSEG = 1. Yes, output each beam spot weld slave node and its master segment for *CONTACT_SPOTWELD into D3HSP file. • SPOTSTP = 0 (default).

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Supported LS-DYNA Keywords • SPOTDEL = 1.Yes, delete the attached spot weld element if the nodes of a spot weld beam or solid element are attached to a shell element that fails and the nodes are deleted. • SPOTHIN = 0.5. This factor can be used to scale the thickness of parts within the vicinity of the spot weld. This factor helps avert premature weld failures due to contact of the welded parts with the weld itself. Should be greater than zero and less than one.

*CONTROL_ENERGY Specifies the controls for energy dissipation options. Card • HGEN = 2. Hourglass energy is computed and included in the energy balance. Results are reported in ASCII files GLSTAT and MATSUM. • RWEN = 2 (default). • SLNTEN = 2. Sliding interface energy dissipation is computed and included in the energy balance. Results are reported in ASCII files GLSTAT and SLEOUT. • RYLEN = 2. Rayleigh energy dissipation is computed and included in the energy balance. Results are reported in ASCII file GLSTAT.

*CONTROL_HOURGLASS Specifies the global hourglass parameters. Card • IHQ = 1 if Hourglass Damping of type Standard is selected in the Analysis Settings. Also this parameter is equal to 1 if the Flanagan Belytschko option is selected but both the coefficients are zero. = 5 if the Flanagan Belytschko option is selected and the Stiffness Coefficient is non-zero. = 3 if the Flanagan Belytschko option is selected, the Stiffness Coefficient is zero and the Hex Integration Type of the Solver Controls is set to Exact. = 2 if the Flanagan Belytschko option is selected, the Stiffness Coefficient is zero and the Hex Integration Type of the Solver Controls is set to 1pt Gauss. • QH = Viscous Coefficient of the Hourglass Damping section of the Analysis Settings if IHQ is equal to 1, 2, or 3. = Stiffness Coefficient if IHQ is 5.

*CONTROL_SHELL Specifies global parameters for shell element types. Card • WRPANG = 20 (default).

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LS-DYNA Keywords Used in an Explicit Dynamics Analysis • ESORT = 1, full automatic sorting of triangular shell elements to treat degenerate quadrilateral shell elements as C0 triangular shells. • IRNXX = -2, shell normal update option. When set to -2 unique nodal fibers are incrementally updated based on the nodal rotation at the location of the fiber. • ISTUPD = 4, shell thickness update option for deformable shells. Membrane strains cause changes in thickness in 3 and 4 node shell elements, however elastic strains are neglected. This option is very important in sheet metal forming or whenever membrane stretching is important. For crash analysis, setting 4 may improve energy conservation and stability. • THEORY = 2 (default). Belytschko-Tsay formulation. • BWC = 1 if Shell BWC Warp Correction option is set to Yes in the Solver Controls section of the Analysis Settings. For this setting, Belytschko-Wong-Chiang warping stiffness is added. = 2 if Shell BWC Warp Correction option is set to No. • MITER = 1 (default). Plane stress plasticity: iterative with 3 secant iterations. • PROJ = 1, the full projection method is used for the warping stiffness in the Belytschko-Tsay and Belytschko-Wong-Chiang shell elements. This option is required for explicit calculations.

*CONTROL_SOLID Specifies global parameters for solid element types. Card • ESORT = 1, full automatic sorting of tetrahedron and pentahedron elements to treat degeneracies. Degenerate tetrahedrons will be treated as ELFORM = 10 and pentahedron as ELFORM = 15 solids respectively (see *SECTION_SOLID).

*CONTROL_TERMINATION Specifies the termination criteria for the solver. Card • ENDTIM = End Time in the Step Controls section of the Analysis Settings. • ENDCYC = Maximum Time Steps of the Step Controls section of the Analysis Settings. • DTMIN = 0.01 (constant). • ENDENG = Maximum Energy Error from the Step Controls section of the Analysis Settings. • ENDMAS = Maximum Part Scaling from the Step Controls section of the Analysis Settings, if Automatic Mass Scaling is set to Yes. If Automatic Mass Scaling is set to No, the default value of 0.0 is used.

*CONTROL_TIMESTEP Specifies conditions for determining the computational time step. Card 1626

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Supported LS-DYNA Keywords • DTINIT = Initial Time Step from the Step Controls section of the Analysis Settings. • TSSFAC = Time Step Safety Factor from the Step Controls section of the Analysis Settings. • ISDO = 0 (default). Basis of time size calculation for 4-node shell elements. • TSLIMT = Minimum Element Timestep from the Erosion Controls section of the Analysis Settings, if On Minimum Element Timestep is set to Yes. If On Minimum Element Timestep is set to No the default value of 0.0 is used. • DT2MS = the negative value of Minimum CFL Timestep specified in the Step Controls section of the Analysis Settings, if Automatic Mass Scaling is set to Yes. If Automatic Mass Scaling is set to No the default value of 0.0 is used. • LCTM = ID of the load curve which uses Maximum Time Step from the Step Controls section of the Analysis Settings. • ERODE = 1 (constant). • MS1ST = 0 (default).

*DAMPING_GLOBAL Specifies the mass weighted nodal damping applied globally to the nodes of deformable bodies and the center of mass of rigid bodies. Card • LCID = 0, a constant damping factor will be used as specified in VALDMP. • VALDMP = Static Damping from the Damping Controls section of the Analysis Settings.

*DATABASE_BINARY_D3PLOT Specifies the sampling parameters for the binary D3PLOT results plotting file. Card • DT = Time from the Output Controls section of the Analysis Settings if Save Results on is set to Time. = End Time divided by the Number of Points if Save Results On is set to Equally Spaced Points.

*DATABASE_BINARY_RUNRSF Specifies the sampling parameters for the RUNRSF restart file. Card • CYCL = Time Steps from the Output Controls section of the Analysis Settings if Save Restart Files on is set to Time Steps. = Maximum Time Steps divided by the Number of Points if Save Results On is set to Equally Spaced Time Points.

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LS-DYNA Keywords Used in an Explicit Dynamics Analysis

*DATABASE_ELOUT Specifies the sampling parameters for the ELOUT results file (stores stress and strain results). Card • DT = (see *DATABASE_BINARY_D3PLOT).

*DATABASE_FORMAT Specifies the format in which to write binary results files like D3PLOT and D3THDT. Card • IFORM = 0, binary results will be written only in the LS-DYNA format.

*DATABASE_GLSTAT Specifies the sampling parameters for the GLSTAT results file (stores general energy results). Card • DT = (see *DATABASE_BINARY_D3PLOT).

*DATABASE_MATSUM Specifies the sampling parameters for the MATSUM results file (stores general energy and velocity results as the GLSTAT file but it stores them per body. It is necessary for rigid bodies). Card • DT = (see *DATABASE_BINARY_D3PLOT).

*DATABASE_NODOUT Specifies the sampling parameters for the NODOUT results file (stores displacement and velocity results). Card • DT = (see *DATABASE_BINARY_D3PLOT).

*DEFINE_COORDINATE_SYSTEM Specifies a local coordinate system with three points: one at the local origin, one on the local x-axis and one on the local x-y plane. Card1 • CID = ID of the coordinate system, must be unique. • XO = global X-coordinate of the origin. • YO = global Y-coordinate of the origin. • ZO = global Z-coordinate of the origin. 1628

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Supported LS-DYNA Keywords • XL = global X-coordinate of a point on the local x-axis. • YL = global Y-coordinate of a point on the local x-axis. • ZL = global Z-coordinate of a point on the local x-axis. Card2 • XP = global X-coordinate of a point on the local x-y plane. • YP = global Y-coordinate of a point on the local x-y plane. • ZP = global Z-coordinate of a point on the local x-y plane.

*DEFINE_CURVE Specifies magnitudes that are given in tabular format. Some keywords require magnitudes to be specified as a load curve. Should a constant be needed, it may be represented as a curve by repeating its value for time steps 0 and 1. Card1 • LCID = ID for load curve, is incremented every time a new load curve is defined. Card2, 3, 4… • A = abscissa value, usually time. • O = ordinate (function) value.

*DEFINE_VECTOR Specifies a vector by defining the coordinates of two points. This keyword defines the local coordinate system with respect to which a *BOUNDARY_PRESCRIBED_MOTION is prescribed. The ID of this coordinate system is specified with parameter CID. Card • VID = ID of the vector. • XT = 0, the local x-coordinate of the origin of the coordinate system specified with CID below. • YT = 0, the local y-coordinate of the origin of the coordinate system specified with CID below. • ZT = 0, the local z-coordinate of the origin of the coordinate system specified with CID below. • XH = 1 if the vector has a component in the x direction of the coordinate system specified with CID. Otherwise, this is set to 0. • YH = 1 if the vector has a component in the x direction of the coordinate system specified with CID. Otherwise, this is set to 0. • ZH = 1 if the vector has a component in the x direction of the coordinate system specified with CID. Otherwise, this is set to 0.

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LS-DYNA Keywords Used in an Explicit Dynamics Analysis • CID = ID of the coordinate system used to define the vector. If no coordinate system is specified this parameter is set to 0 to specify the global coordinate system.

*ELEMENT_BEAM Specifies beam elements. Card • EID = ID of the element. • PID = ID of the part it belongs to. • N1 = ID of nodal point 1. • N2 = ID of nodal point 2. • N3 = ID of nodal point 3, used for cross section orientation.

*ELEMENT_SHELL Specifies three, four, six and eight noded shell elements. Card • EID = ID of the element. • PID = ID of the part it belongs to. • N1 = ID of nodal point 1. • N2 = ID of nodal point 2. • N3 = ID of nodal point 3. • N4 = ID of nodal point 4. • N5-8 = ID of mid side nodes for six and eight noded shells.

*ELEMENT_SHELL_THICKNESS_OFFSET This keyword is the same as *ELEMENT_SHELL above with two additional cards for specifying thicknesses per node and the offset of the shell. Card1 — the same as *ELEMENT_SHELL Card2 • THIC1 = shell thickness at node 1. • THIC2 = shell thickness at node 2. • THIC3 = shell thickness at node 3. • THIC4 = shell thickness at node 4.

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Supported LS-DYNA Keywords • BETA or MCID = 0 (Default). These parameters specify the base offset angle for Orthotropic materials. Card3 • OFFSET = offset distance from the nodal points plane to the reference surface of the shell. This is specified in the direction of the normal vector of the shell.

*ELEMENT_SOLID Specifies 3D solid elements including 10-noded tetrahedrons (second order). Apart from the second order case the two cards are combined into one. Card1 • EID = ID of the element. • PID = ID of the part it belongs to. Card2 • N1 = ID of nodal point 1. • N2 = ID of nodal point 2. • N3 = ID of nodal point 3. • N4 = ID of nodal point 4. • . • . • . • N10 = ID of nodal point 10.

*END Terminates the keyword file. It has no parameter cards.

Equation Of State (EOS) keywords The following are descriptions for *EOS keywords natively supported by the LS-DYNA export feature. More generally, any *EOS keyword may be introduced into the export file with the help of Commands objects in the Mechanical application (termed Keyword Snippet when referring to the LS-DYNA solver). To use it, insert a Keyword Snippet under a Geometry body in the Tree Outline. The program will automatically substitute the EOSID parameter, in accordance with the *PART keyword (see below) of the associated body. All other parameters in the Keyword Snippet are transcribed literally, overriding any values that would otherwise derive from the Engineering Data workspace. If the *EOS keyword is entered in a Keyword Snippet anywhere else in the Tree Outline, it will be exported literally and the Engineering Data EOS information will also be exported, if present. This practice is not recommended, however, and a warning is provided in the header of Keyword Snippet objects when detected.

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LS-DYNA Keywords Used in an Explicit Dynamics Analysis

*EOS_GRUNEISEN Specifies a shock equation of state. This keyword is created when a Shock EOS linear equation of state is present in the properties of a material that is used in the simulation and the Johnson Cook plasticity model is also present. The bilinear version of this equation of state is not currently supported. Card1 • EOSID = ID of the keyword, must be unique between the *EOS keywords. • C = parameter C1 for a Linear Shock EOS property. • S1 = parameter S1 for a Linear Shock EOS property. • S2 = Parameter Quadratic S2 for a Linear Shock EOS property. • S3 = 0. • GAMAO = Gruneisen Coefficient for a Linear Shock EOS property. • A = 0. Card2 — mandatory, left blank.

*EOS_LINEAR_POLYNOMIAL Specifies the coefficients for a linear polynomial elastic EOS. The *EOS_LINEAR_POLYNOMIAL keyword is only created when the Johnson Cook strength property is added to the material model (which requires an EOS), but no other EOS has been specified. It is not directly available from the Engineering Data workspace, however. Card1 • EOSID = ID of the keyword, must be unique between the *EOS keywords. • C0 = 0. • C1 = elastic bulk modulus • C2 = 0. • C3 = 0. • C4 = 0. • C5 = 0. • C6 = 0. Card2 — mandatory, left blank.

*HOURGLASS Defines hourglass and bulk viscosity properties that are referenced in the *PART keyword via its HGID parameter (see *PART keyword bellow).

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Supported LS-DYNA Keywords This keyword can only be created directly with the Keyword Snippet(also, Commands objects) for the LS-DYNA solver. To use it, insert a Keyword Snippet under a Geometry body in the Tree Outline. The program will automatically substitute the HGID parameter in accordance with the *PART keyword (see below) of the associated body. All other parameters in the Keyword Snippet are transcribed literally. If the keyword is entered in a Keyword Snippet anywhere else in the Tree Outline, it will be exported literally. This practice is not recommended, however, and a warning is provided in the header of Keyword Snippet objects when detected.

*INITIAL_VELOCITY_GENERATION Specifies initial translational and rotational velocities. Card1 • ID = ID of part where the initial velocity is applied. • STYP = 2, the velocity is applied to a whole part. In Workbench initial velocities can only be applied to whole parts. • OMEGA = angular velocity about the rotational axis. • VX = initial translational velocity in the x direction. • VY = initial translational velocity in the y direction. • VZ = initial translational velocity in the z direction. • IVATN = 0 (default) slave bodies of a multibody part are not assigned the initial velocities of the master part. Card2 • XC = x coordinate of the origin of the applied coordinate system. • YC = y coordinate of the origin of the applied coordinate system. • ZC = z coordinate of the origin of the applied coordinate system. • NX = 0 if there is no angular velocity around the x-axis. = 1 if there is angular velocity around the x-axis. • NY = 0 if there is no angular velocity around the y-axis. = 1 if there is angular velocity around the y-axis. • NZ = 0 if there is no angular velocity around the z-axis. = 1 if there is angular velocity around the z-axis. • PHASE = 0 (default), velocities are applied immediately.

*INITIAL_VELOCITY_RIGID_BODY Specifies initial translational and rotational velocities at the center of gravity for rigid bodies. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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LS-DYNA Keywords Used in an Explicit Dynamics Analysis Card • PID = ID of the rigid body. • VX = initial translational velocity in the x direction. • VY = initial translational velocity in the y direction. • VZ = initial translational velocity in the z direction. • VXR = initial rotational velocity around the x-axis. • VYR = initial rotational velocity around the y-axis. • VZR = initial rotational velocity around the z-axis.

*INTEGRATION_BEAM Specifies the particulars of the integration method required for complex or user-defined cross sections of beam elements. Card1 • IRID = incremented every time a new keyword is required. • NIP = 0, number of integration points are not specified, instead ICST is used below to choose a standard cross sectional area. • RA = 0, number of integration points are not specified, instead ICST is used below to choose a standard cross sectional area. • ICST = 1-21 depending on the cross sectional area specified in the GUI for the beam geometry. Card2 • D1-D4 = cross sectional dimensions for width and height. • SREF = 1, orientation for s-axis. • TREF = 1, orientation for t-axis.

*KEYWORD Marks the beginning of a keyword file.

*LOAD_BODY_X Specifies gravitational or other acceleration loads in the x direction. The load is applied to all nodes in the model. Card • LCID = ID of the load curve that represents the magnitude of the load (see *DEFINE_CURVE). • SF = 1.0 (default), load curve scale factor.

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Supported LS-DYNA Keywords • LCIDDR = 0 (default), ID of load curve defined for dynamic relaxation. • XC = 0.0 (default), X-center of rotation needed for angular velocities. • YC = 0.0 (default), Y-center of rotation needed for angular velocities. • ZC = 0.0 (default), Z-center of rotation needed for angular velocities. • CID = ID of local coordinate system used. Set to 0 for the global coordinate system.

*LOAD_BODY_Y Specifies gravitational or other acceleration loads in the y direction. The load is applied to all nodes in the model. Card (see *LOAD_BODY_X).

*LOAD_BODY_Z Specifies gravitational or other acceleration loads in the z direction. The load is applied to all nodes in the model. Card (see *LOAD_BODY_X).

*LOAD_NODE_POINT Applies a concentrated force to a node. Card • NODE = ID of the node on which the force is applied. • DOF = 1, 2 or 3 depending on the force direction x, y or z. • LCID = ID of the load curve that describes the magnitude of the force (see *DEFINE_CURVE). • SF = 1.0 (default), load curve scale factor. • CID = ID of local coordinate system used. Set to 0 for the global coordinate system.

*LOAD_NODE_SET Applies a concentrated nodal force to a set of nodes. Card (see *LOAD_NODE_POINT. Note that parameter NODE here is replaced by NSID which is the ID of the set of nodes where the force is applied).

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LS-DYNA Keywords Used in an Explicit Dynamics Analysis

*LOAD_RIGID_BODY Applies a concentrated nodal force to a rigid body. The force is applied at the center of mass. Card (see *LOAD_NODE_POINT. Note that parameter NODE here is replaced by PID which is the ID of the part the force is applied on).

*LOAD_SEGMENT Applies a distributed pressure load over a triangular or quadrilateral face defined by three, four, six (second order triangles) or eight (second order quadrilateral) nodes. Card • LCID = ID of the load curve that describes the magnitude of the pressure (see *DEFINE_CURVE). • SF = 1.0 (default), load curve scale factor. • AT = arrival time for pressure is assigned the time at load step 1 if pressure is given in tabular form or 0 if constant pressure. • N1-N4 = IDs of nodes that define the face. For triangles N4 = N3. • N5-N8 = IDs of mid-side nodes for second order triangles or quadrilaterals.

Materials keywords The following are descriptions for *MAT keywords natively supported by the LS-DYNA export feature. More generally, any *MAT keyword may be introduced into the export file with the help of Commands objects in the Mechanical application (termed Keyword Snippet when referring to the LS-DYNA solver). To use it, insert a Keyword Snippet under a Geometry body in the Tree Outline. The program will automatically substitute the MID parameter in accordance with the *PART keyword (see below) of the associated body. All other parameters in the Keyword Snippet are transcribed literally, overriding any values that would otherwise derive from the Engineering Data workspace. If the *MAT keyword is entered in a Keyword Snippet anywhere else in the Tree Outline, it will be exported literally and Engineering Data EOS information will also be exported, if present. This practice is not recommended, however, and a warning is provided in the header of Keyword Snippet objects when detected.

*MAT_ELASTIC (or *MAT_001) Specifies isotropic elastic materials. It is available for beam, shell and solid elements. This keyword is used if the selected material includes the Isotropic Elasticity strength model and the Stiffness Behavior is set to Deformable in the Definition section of the body. Card • MID = ID of material type. Must be unique between the material keyword definitions. • RO = density of the material from the Engineering Data workspace.

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Supported LS-DYNA Keywords • E = Young’s modulus of the material from the Engineering Data workspace, either specified directly or calculated from Bulk and Shear moduli. • PR = Poisson’s ratio of the material from the Engineering Data workspace, either specified directly or calculated from Bulk and Shear moduli.

*MAT_HYPERELASTIC_RUBBER (or *MAT_077_H) Specifies a general hyperelastic rubber model, optionally combined with viscoelasticity. This keyword is used if the material includes the Mooney-Rivlin, Polynomial or Yeoh hyperelastic strength model and the Stiffness Behavior is set to Deformable in the Definition section of the body. Card1 • MID = ID of material type, must be unique between the material keyword definitions. • RO = density of the material from the Engineering Data workspace. • PR = Poisson’s ratio of the material from the Engineering Data workspace. Values higher than 0.49 are recommended. Smaller values may not work and should not be used. • N = 0, specifies that the constants in card 2 will be defined. • NV = 0. This parameter is not used if N = 0 above. • G = Shear modulus of the material from the Engineering Data workspace. • SIGF = 0. This parameter is not used if N = 0 above. Card2 • C10 = constant C10 from the Engineering Data workspace. • C01 = constant C01 from the material properties in the Engineering Data. Set to zero for Yeoh models. • C11 = constant C11 from the Engineering Data workspace. Set to zero for Yeoh models. • C20 = constant C20 from the Engineering Data workspace. • C02 = constant C02 from the Engineering Data workspace. Set to zero for Yeoh models. • C30 = constant C30 from the Engineering Data workspace.

*MAT_JOHNSON_COOK (or *MAT_015) Defines a Johnson — Cook type of material. Such materials are useful for problems with large variations in strain rates where adiabatic temperature increases due to plastic heating cause material softening. This keyword is used if the material specified includes a Johnson Cook strength model. Card1 • MID = ID of material type, must be unique between the material keyword definitions. • RO = density of material. • G = Shear modulus of material. Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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LS-DYNA Keywords Used in an Explicit Dynamics Analysis • E = Young’s modulus of the material (shell elements only). • PR = Poisson’s ratio of the material (shell elements only). Card2 • A = Initial yield stress from the Johnson Cook strength parameters. • B = Hardening Constant from the Johnson Cook strength parameters. • N = Hardening Exponent from the Johnson Cook strength parameters. • C = Strain Rate Constant from the Johnson Cook strength parameters. • M = Thermal Softening Exponent from the Johnson Cook strength parameters. • TM = Melting Temperature from the Johnson Cook strength parameters. • TR = 15, room temperature. • EPSO = Reference Strain Rate from the Johnson Cook strength parameters. Card3 • CP = Specific Heat from the material properties. • PC = 0 (LS-DYNA default). • SPALL = 2.0 (LS-DYNA default). • IT = 0 (LS-DYNA default). • D1 = D1 parameter of the Johnson Cook failure model definition, if present. Otherwise it is 0. • D2 = D2 parameter of the Johnson Cook failure model definition, if present. Otherwise it is 0. • D3 = D3 parameter of the Johnson Cook failure model definition, if present. Otherwise it is 0. • D4 = D4 parameter of the Johnson Cook failure model definition, if present. Otherwise it is 0. Card4 • D5 = D5 parameter of the Johnson Cook failure model definition, if present. Otherwise it is 0. • C2/P = «Reference Strain Rate (/sec)» parameter of the Johnson Cook failure model definition, if present. Otherwise it is 0.

*MAT_OGDEN_RUBBER (or *MAT_077_O) Specifies the Ogden rubber model, optionally combined with viscoelasticity. This keyword is used if the material includes the Ogden hyperelastic strength model and the Stiffness Behavior is set to Deformable in the Definition section of the body. For card 1 see *MAT_HYPERELASTIC_RUBBER Card2

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Supported LS-DYNA Keywords • MU1 = Material Constant MU1 from the Ogden model. • MU2 = Material Constant MU2 from the Ogden model. • MU3 = Material Constant MU3 from the Ogden model. • MU4 = 0. • MU5 = 0. • MU6 = 0. • MU7 = 0. • MU8 = 0. Card3 • ALPHA1 = Material Constant A1 from the Ogden model. • ALPHA2 = Material Constant A2 from the Ogden model. • ALPHA3 = Material Constant A3 from the Ogden model. • ALPHA1 = 0. • ALPHA1 = 0. • ALPHA1 = 0. • ALPHA1 = 0. • ALPHA8 = 0.

*MAT_ORTHOTROPIC_ELASTIC (or *MAT_002) Specifies the model for an elastic-orthotropic behavior of solids, shells and thick shells. This keyword is created when the Orthotropic Elasticity property is present in a material that is used. The Poisson’s ratios required with this keyword must be in their minor version, however Workbench requires their major versions hence they are converted by multiplying them by the relevant Young’s modulus ratios. Card1 • MID = ID of material type, must be unique between the material keyword definitions. • RO = density of material. • EA = Young’s Modulus X direction from the Orthotropic Elasticity model. • EB = Young’s Modulus Y direction from the Orthotropic Elasticity model. • EC = Young’s Modulus Z direction from the Orthotropic Elasticity model. • PRBA = Poisson’s Ratio XY from the Orthotropic Elasticity model multiplied by Young’s Modulus Y / Young’s Modulus X.

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LS-DYNA Keywords Used in an Explicit Dynamics Analysis • PRCA = Poisson’s Ratio YZ from the Orthotropic Elasticity model multiplied by Young’s Modulus Z / Young’s Modulus X. • PRCB = Poisson’s Ratio XZ from the Orthotropic Elasticity model multiplied by Young’s Modulus Z / Young’s Modulus Y. Card2 • GAB = Shear Modulus XY from the Orthotropic Elasticity model. • GBC = Shear Modulus YZ from the Orthotropic Elasticity model. • GCA = Shear Modulus XZ from the Orthotropic Elasticity model. • AOPT = 0 (default). When this parameter is set to zero the locally orthotropic material axes are determined from three element nodes. The first node specifies the local origin, the second specifies one of the axes and the third specifies the plane on which the axis rests. = — ID of local coordinate system assigned to the body with this material model. Card3 — mandatory, left blank. Card4 — mandatory, left blank.

*MAT_MODIFIED_PIECEWISE_LINEAR_PLASTICITY (or *MAT_123) Defines elasto-plastic materials with arbitrary stress-strain curve and arbitrary strain rate dependency. This keyword is used if the material specified includes a Bilinear or Multilinear Isotropic Hardening (BISO or MISO) strength model. Cards 3 and 4 bellow, are only used if the strength model is MISO. Card1 • MID = ID of material type, must be unique between the material keyword definitions. • RO = density of material. • E = Young’s modulus of the material. • PR = Poisson’s ratio of the material. • SIGY = Yield Strength from the BISO strength model. It is not required for MISO models. • ETAN = Tangent Modulus from the BISO strength model. It is not required for MISO models. • FAIL = Maximum Equivalent Plastic Strain EPS parameter of the Plastic Strain failure model, if present. Otherwise it is set to 10E+20. Card2 • C = 0. • P = 0. • LCSS = 0. Card3 — specified only for MISO models. Otherwise it is left blank.

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Supported LS-DYNA Keywords • EPS1 = Plastic Strain data from the MISO strength model. If the strength model contains more than 8 data points, the extra data set is ignored. • EPS2 = • EPS3 = • … • EPS8 = Card4 — specified only for MISO models. Otherwise it is left blank. • ES1 = Yield Stress data that correspond to the above plastic strain data. If the strength model contains more than 8 data points, the extra data set is ignored. • ES2 = • ES3 = • … • ES8 =

*MAT_PLASTIC_KINEMATIC (or *MAT_003) Specifies isotropic and kinematic hardening plastic behavior in materials. This keyword is created when the Bilinear Kinematic Hardening (BKIN) strength model is present in a material. Card1 • MID = ID of material type, must be unique between the material keyword definitions. • RO = density of material. • E = Young’s modulus of the material. • PR = Poisson’s ratio of the material. • SIGY = Yield Strength from the BKIN strength model. • ETAN = Tangent Modulus from the BKIN strength model. • BETA = 0. Card2 • SRC = left blank. • SRP = left blank. • FS = Maximum Equivalent Plastic Strain EPS parameter of the Plastic Strain failure model, if present. Otherwise it is left blank.

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LS-DYNA Keywords Used in an Explicit Dynamics Analysis

*MAT_RIGID (or *MAT_020) Specifies materials for rigid bodies. This keyword is created when the Stiffness Behavior is set to Rigid under the Definition section of the body. Any strength or EOS material properties defined are ignored. Card1 • MID = ID of material type, must be unique between the material keyword definitions. • RO = density of material. • E = Young’s modulus of the material. • PR = Poisson’s ratio of the material. Card2 • CMO = 0 if there are no constraints on the rigid body. = -1 if rigid body is constrained in any way. • CON1 = 0 if there are no constraints on the rigid body. = Local Coordinate System ID if associated with the constraint. Otherwise it is set to 0. • CON2 = 0 if there are no constraints on the rigid body. = 111111 if the body is constrained with a fixed support or with a combination of a simple support and a fixed rotation. = 111000 if the body is constrained with a simple support. = 000111 if the body is constrained with a fixed rotation. Card3 • LCO = CON1 if non-zero. Otherwise it will remain blank.

*NODE Defines nodes. All the parameters are obtained from mesh definitions of the model. Card • NID = ID of the node. • X = x coordinate. • Y = y coordinate. • Z = z coordinate.

*PART Defines geometry bodies.

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Supported LS-DYNA Keywords Card1 • HEADING = name of the body specified in the Workbench environment. Card2 • PID = ID of the part. It is set in the LS-DYNA solver and does not reflect the ID specified in the mesh definition of the model. • SECID = ID of the section keyword associated with the part (see *SECTION). • MID = ID of the material keyword associated with the part (see *MAT). • EOSID = ID of the equation of state associated with the material of this part (*EOS and *MAT). If there is no EOS keyword associated with this part then this parameter is set to 0. • HGID = ID of the hourglass keyword associated with the part (see *HOURGLASS). If there is no hourglass keyword associated with this part then this parameter is set to 0.

*SECTION_BEAM Defines cross sectional properties for beam, truss, spot weld and cable elements. Card1 • SECID = ID of the section. • ELFORM = 1. The element formulation option is changed to 3 if the Beam Solution Type option of the Analysis Settings is set to Truss. • SHRF = 1.0 (default). If the cross sectional shape is rectangular or complex (see CST bellow) then SHRF is set to 0.833. • QR = 2 (default), quadrature rule is 2×2 Gauss. If the cross sectional area of the beam is complex or userdefined, this parameter becomes IRID and is assigned the negative value of the IRID parameter in the corresponding *INTEGRATION_BEAM keyword (see above for details). • CST = 0 for solid cross sections = 1 for hollow cross sections = 2 for complex or user defined cross sections. Such cross sections include: hollow rectangular, I, C, L, T, Z, trapezoidal, U and hat shapes. Card2 • for solid types – TS1 = width of beam. This refers specifically to the dimension at node 1. – TS2 = TS1. This refers specifically to the dimension at node 2. – TT1 = height of beam. This refers specifically to the dimension at node 1. Set to zero circular solids. – TT2 = TT1. This refers specifically to the dimension at node 2. Set to zero circular solids.

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LS-DYNA Keywords Used in an Explicit Dynamics Analysis • for hollow circular types – TS1 = outer diameter of beam. This refers specifically to the dimension at node 1. – TS2 = TS1. This refers specifically to the dimension at node 2. – TT1 = inner diameter of beam. This refers specifically to the dimension at node 1. – TT2 = TT1. This refers specifically to the dimension at node 2. • for truss types – A = cross-sectional area. • for general symmetric types – A = cross-sectional area. – ISS = Iyy, moment of inertia about the local s-axis. – ITT = Izz, moment of inertia about the local t-axis.

*SECTION_SHELL Defines section properties for shell elements. Card1 • SECID = ID of the section. • ELFORM = 2, if the Full Shell Integration option of the Solver Controls of the Analysis Settings is set to No. = 16 (default) if the Full Shell Integration option of the Solver Controls of the Analysis Settings is set to Yes. • SHRF = Shell Shear Correction Factor option of the Solver Controls of the Analysis Settings. The default value is set to 0.8333. • NIP = Shell Sublayers option of the Solver Controls of the Analysis Settings. The default value is 3. Card2 • T1 = thickness of body. • T2-T4 = T1, shell thickness at nodes 2, 3 and 4.

*SECTION_SOLID Defines section properties for solid elements. Card • SECID = ID of the section.

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Supported LS-DYNA Keywords • ELFORM = 1 (default). Also, used for first-order hexahedral elements, 5-noded pyramids, 6-noded wedges or bodies with mixed element types that include tetrahedrons together with hexahedrons, pyramids or wedges. = 10 if elements are first-order tetrahedrons and Tet Pressure Integration option of the Solver Controls of the Analysis Settings is set to Constant. = 13 if elements are first-order tetrahedrons and Tet Pressure Integration option of the Solver Controls of the Analysis Settings is set to Average Nodal. = 16 if the elements are second-order tetrahedrons.

*SET_NODE_LIST Defines a set of nodes. Card2 is repeated as many times as required to specify all the node IDs in the set. Card1 • SID = ID of the set. Card2 • NID1-NID8 = IDs for eight of the nodes in the set.

*SET_PART_LIST Defines a set of parts. Card2 is repeated as many times as required to specify all the part IDs in the set. Card1 • SID = ID of the set. Card2 • PID1-PID8 = IDs for eight of the parts in the set.

*SET_SEGMENT Defines triangular and quadrilateral segments. Card2 is repeated as many times as required to specify all the segments in the set. Card1 • SID = ID of the set. Card2 • N1-N4 = IDs of nodes that define one of the segments. For triangular segments N4=N3.

*TITLE Defines a job title. Card Release 15.0 — © SAS IP, Inc. All rights reserved. — Contains proprietary and confidential information of ANSYS, Inc. and its subsidiaries and affiliates.

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LS-DYNA Keywords Used in an Explicit Dynamics Analysis • TITLE = a user input. This can only be entered manually after the .k file is exported.

LS-DYNA General Descriptions All the exported keywords are grouped into their respective sections in the .k file. These sections are the same as the ones used by the Mechanical APDL application exporting facility apart from the «KEYWORD SNIPPETS» section. The section titles and their order is the following: • NODE DEFINITIONS • SECTION DEFINITIONS • MATERIAL DEFINITIONS • PARTS DEFINITIONS • ELEMENT DEFINITIONS • LOAD DEFINITIONS • CONTACT DEFINITIONS • CONTROL OPTIONS • TIME HISTORY • INITIAL VELOCITY DEFINITIONS • LIST SETS • BOUNDARY CONDITIONS • KEYWORD SNIPPETS Keyword-snippets are supported for geometry bodies, for Connections and the Explicit Dynamics analysis section. For geometry bodies, you can enter LS-DYNA specific material and equation of state types together with the *HOURGLASS keyword. These keywords should always have a non zero value entered for their ID. This is usually the first parameter of the keyword and can be any integer that fits within the 10 character field-width of the parameter. The same number can be entered for all of these keywords as the software will replace it with an appropriate unique value. The IDs of these keywords will be assigned to the *PART keyword associated with the body that the keyword-snippet belongs to. You will be informed with a comment shown at the beginning of the text editor of the snippet, about the keywords that should be entered. For the Connections, you can enter LS-DYNA contact keywords which are not available for definition from the GUI. These keywords can be assigned to the geometry by using the names of pre-defined Named Selections. When the keywords are exported, these names will be replaced with IDs from the *SET keywords created for the relevant Named Selections. If the contact region associated with the Keyword Snippet has its scoping defined, by entering «contact» and «target» for the master and slave entries of the contact keyword, the IDs of the *SET keywords for the Contact Region scoping will be used instead. One contact keyword should be entered per snippet, which can be followed by as many other keywords as required. The latter will not be processed and will be exported as entered.

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LS-DYNA General Descriptions For the analysis, you will be asked to enter global parameters with keywords like *CONTROL and *DATABASE. As these parameters are global they do not need to be associated with any other keywords so their contents will only be transferred to the .k file and will not be utilized in any other way. Other project tree entries apart from the ones mentioned above, where keyword snippets could be useful can be implemented at a later date if requested, or proved to be necessary. Keywords that are entered with the keyword-snippet facility are grouped under a common section called «KEYWORD SNIPPETS» at the end of the .k file. Named selections whether having anything assigned to them or not, like for example a load or constrain, will be exported as a set of IDs. This set can then be used in LS-PREPOST or by editing the .k file manually to assign LS-DYNA specific keywords which are not represented in Workbench. Due to the restriction of the field widths specified for each keyword, if the number to be used has more characters than the field width allows, the following process is followed to make sure the number fits within the field: • The number is converted to scientific. • If the scientific format is still larger than the required field width then digits are removed from the decimal part. This is done by cleaning first the exponential number from any leading zeroes. • If all the decimals are removed and the number is still larger then digits from the mantissa are removed and the exponent increased by 1 for every digit removed.

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Appendix E.Workbench Mechanical Wizard Advanced Programming Topics This appendix examines programming techniques and provides a reference for customizing the Mechanical Wizard.

Topics Overview (p. 1649) URI Address and Path Considerations (p. 1650) Using Strings and Languages (p. 1651) Guidelines for Editing XML Files (p. 1652) About the TaskML Merge Process (p. 1652) Using the Integrated Wizard Development Kit (WDK) (p. 1653) Using IFRAME Elements (p. 1653) TaskML Reference (p. 1654) Standard Object Groups Reference (p. 1686) Tutorials (p. 1689) Wizard Development Kit (WDK) Groups (p. 1699)

Overview From a programming perspective, the Mechanical Wizard system is best described as a «task browser.» As a «web browser» used to view and navigate pages on the Internet, a task browser is used to view and navigate tasks in an engineering system. A web browser accesses HTML files and resources on a network; a task browser accesses TaskML files and resources on a network. TaskML is an XML vocabulary that defines the rules and data necessary to display and process pages of tasks in the Mechanical application. Like HTML, TaskML allows for general scripting and for inserting arbitrary HTML content and user interface controls. Basic wizard customization using TaskML is similar to working with HTML and requires only a text editor. The Mechanical Wizard runs as a web application (specifically, a dynamic HTML page) inside of a web browser control (Microsoft Internet Explorer). The web browser control is hosted by the Mechanical application. Consequently, the Mechanical Wizard system has full access to the capabilities of the web browser and the Mechanical application. Development of the Mechanical Wizard involves use of the HTML, CSS, XML, JScript web standards, and, for access to and automation of the application, use of the Mechanical application object model. The Mechanical Wizard displays tasks organized into groups. A task displays a caption and a status or descriptive icon. Activating a task (by clicking) typically involves automatic navigation to a particular context and selection in the user interface and display of a «callout» with a text message pointing to a specific control. Custom tasks may perform any operation via TaskML elements or scripting. The Mechanical Wizard responds to events that occur in the Mechanical application. Adding a load is an example of an event. When such an event occurs, each task is given the opportunity to determine its status or take an action.

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Workbench Mechanical Wizard Advanced Programming Topics The user may open a TaskML file inside the Mechanical Wizard from their local disk or from a network location. Therefore, saving TaskML to a network server makes custom wizard definitions available to any user with access to the server. Additionally, the Mechanical Wizard system itself may be run by any number of clients from a network location. TaskML, along with HTML and scripting, offers an efficient and powerful means of extending the Mechanical application user interface.

URI Address and Path Considerations The Merge (p. 1656), Script (p. 1656), task (p. 1663), set-icon (p. 1684), open-url (p. 1678), display-help-topic (p. 1675) and iframe (p. 1666) TaskML elements use URIs to link together files to form a complete wizard definition. TaskML supports the following URI formats.

Note Standard network security conditions apply to these URIs. As a general rule, if a user cannot open a linked file in their web browser, the file cannot be accessed by the Mechanical Wizard.

Local Machine and LAN C:\folder\Wizard.xml M:\folder\Wizard.xml \\server\share\Wizard.xml

Standard Protocols http://webserver/share/Wizard.xml ftp://ftp.webserver.com/pub/Wizard.xml file:///C:/folder/Wizard.xml

SIMWIZ Protocol The SIMWIZ protocol supports paths relative to the location of the Mechanical Wizard (specifically, relative to the location of the file Default.htm in the Mechanical Wizard folder). The SIMWIZ protocol allows custom TaskML files published to any arbitrary location to reuse standard TaskML files and other components of the system. simwiz://Tasks/StandardTasks.xml

Relative Paths All relative paths are relative to the location of the file containing the link. Note that this behavior is different from version 6.0, in which relative links were relative to the location of the Mechanical Wizard. folder/Wizard.xml ./folder/Wizard.xml ../folder/Wizard.xml /rootfolder/Wizard.xml

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Using Strings and Languages

Using Strings and Languages The Mechanical Wizard obtains all strings from TaskML. The language-related section of the TaskML uses the following structure: <strings>

<string id=»String_ID»>Sample Text

The Mechanical Wizard determines which strings to use by matching the Language setting in the Wizard page of the Control Panel to the xml:lang attribute of a language element. If no language element with a matching xml:lang attribute exists, or if no string element with the necessary ID exists, the Mechanical Wizard takes the string from the language element with the xml:lang attribute set to «enus» (English, United States). If the default English string doesn’t exist, the Mechanical Wizard takes the first string with a matching ID or displays the string ID in place of the text.

Recommended Localization Process This process describes how to localize all strings in a TaskML file: 1. Open the TaskML file in a text editor. 2. Copy the section of the file from:

to

3. Paste the copy into the<string> element below the last

close tag. 4. Change the language code from en-us to the code appropriate for the localization. 5. Localize each <string> element within the new element. String IDs must remain unchanged. 6. Test the new language by entering the language code in the Language setting in the Wizard page of the Control Panel.

English Customization Process This process describes how to customize individual English strings with specific information or terminology: 1. Create a new

element at the bottom of the <string> element below the last close tag. Set the xml:lang attribute to an arbitrary “x-code” descriptive of the customization (no spaces). 2. Copy individual <string> elements to customize from the < language xml: lang=»en-us»> element to the new element. Strings omitted from the new element will be obtained from the element. 3. Customize the strings. String IDs must remain unchanged.

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Guidelines for Editing XML Files TaskML is an XML vocabulary. As such, TaskML consists of Unicode (wide character) text files that must follow the standard XML rules for well-formedness. When editing a TaskML file, use caution to ensure that the XML remains well-formed. For example, omitting a close tag will cause an error and may prevent the wizard from loading. To test for well-formedness, open the file in Internet Explorer 5 or later.

Note • XML is case-sensitive. All TaskML tags are lower-case. • Attribute values must be in quotes. • Use only the five predefined XML entity references for special characters if needed: & (&), < (<) > (>) » («) ‘ (&apo;). • White space (new lines, tabs, etc) is generally discarded. However, within a string element extra white space may result in multiple spaces between words. At this release there is no way to insert a line break within a string element. • string elements contain only text; string (p. 1661) elements may not contain any XML or HTML elements. • XML comments are allowed.

About the TaskML Merge Process The merge process facilitates reuse of wizard components from local or network locations. The merge process is the first step in loading TaskML into the Mechanical Wizard. The process involves selectively copying information from a merged TaskML document into a parent TaskML document. The parent document includes a Merge (p. 1656) element linking to the merged file. The merge process generates a composite TaskML document in memory; neither the parent or merged TaskML files are modified. The merge process consists of the following steps: 1. If the merged TaskML document contains Merge (p. 1656) elements, this process is called recursively. That is, a TaskML document may merge a file that merges a file, and so on. 2. Script (p. 1656) elements are copied to the parent only if the src attribute is unique. 3. object-group (p. 1657) elements are copied to the parent only if the merged object-group has a unique name attribute. 4. status (p. 1659) elements are copied to the parent only if the merged status has a unique id. 5. language (p. 1660) collections (and contained string elements) are copied only if the language has a unique xml:lang attribute.

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Using IFRAME Elements 6. string (p. 1661) elements are copied only if the merged string has a unique id. 7. task (p. 1663) elements are copied only if the merged task has a unique id. 8. If both the parent and the merged TaskML documents contain a group (p. 1665) with the same id: • Attributes defined for the merged group but omitted in the parent group are copied to the parent group. • All children of the merged group are appended to the parent group. For diagnostic purposes the merge process automatically adds a merged-from attribute to elements added to the parent TaskML file. The merged-from attribute contains the url of the TaskML file from which the element was obtained.

Using the Integrated Wizard Development Kit (WDK) The Mechanical Wizard system includes an integrated toolkit to assist in customizing wizards. The following topics describe the tools: • WDK: Tools Group • WDK: Commands Group • WDK Tests: Actions • WDK Tests: Flags (Conditions) To enable the toolkit: • In the Mechanical application, select Tools>Options. • Select Wizard and set Enable WDK Tools to yes. Enabling the WDK toolkit adds four groups to the bottom of every panel displayed in the Mechanical Wizard. The WDK toolkit does not change the behavior of other groups in the panel.

Using IFRAME Elements An IFRAME (inline frame) functions as an HTML document within a Mechanical Wizard group. An IFRAME may contain any content, from static text to detailed user interface controls. IFRAMEs have full script access to the Mechanical Wizard, and therefore full access to the Mechanical application. The Options group in the Insert Geometry panel demonstrates a simple user interface extension using an IFRAME. Other examples of IFRAME usage in the Mechanical application include the WDK: Tools group and «Tip of the Day.» IFRAMEs in the Mechanical Wizard provide a way to customize the Mechanical application without modifying the main user interface. IFRAMEs may be published on a network, enabling customized user interfaces for multiple users without requiring changes to each installation. Working with IFRAMEs requires familiarity with HTML and JScript coding. See also Tutorial: Adding a Web Search IFRAME (p. 1693).

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Security Restrictions Due to the cross-frame scripting security model enforced by the web browser control, custom IFRAME HTML pages should reside in the same location as the Mechanical Wizard. IFRAME pages from a different domain as the parent page cannot access the parent via script.

IFRAME Toolkit The WDK includes the following resources for developing IFRAMEs: • The file MechanicalWizard\WDK\Info_IFRAME.htm contains a template HTML document for an IFRAME. View the source for descriptions of recommended HTML elements and JScript functions. • The file MechanicalWizard\System\IFrame.js implements generic functions for use in IFRAMEs. The following files demonstrate use of IFRAMEs: • MechanicalWizard\WDK\Tools_IFrame.htm contains implementation for the WDK: Tools IFRAME. See MechanicalWizard\WDK\Tools_Merge.xml for corresponding TaskML. • MechanicalWizard\Panels\InsertGeometry_IFrame.htm contains implementation for the Insert Geometry panel Options group. See MechanicalWizard\Panels\InsertGeometry.xml for corresponding TaskML. • MechanicalWizard\TipoftheDay\IFrame.htm contains implementation for Tip of the Day. See MechanicalWizard\Panels\Startup.xml for corresponding TaskML.

TaskML Reference This reference describes each element defined in TaskML. See XML Notes for general usage guidelines. The Overview Map contains a diagram showing the basic structure of TaskML. • Document Element (p. 1655) • External References (p. 1656) • Object Grouping (p. 1657) • Status Definitions (p. 1659) • Language and Text (p. 1660) • Tasks and Events (p. 1662) • Wizard Content (p. 1664) • Rules (p. 1667) • Scripting (p. 1685)

Overview Map of TaskML The following illustrates the basic hierarchical structure of TaskML.

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TaskML Reference • simulation-wizard (p. 1655) document element – Merge (p. 1656) elements – Script (p. 1656) elements – object-groups (p. 1658) collection – statuses (p. 1660) collection – strings (p. 1661) collection – tasks (p. 1663) collection → task (p. 1663) elements • update-event (p. 1664) element – Rules (p. 1667) sequence • activate-event (p. 1662) element – Rules (p. 1667) sequence – body (p. 1664) element → group (p. 1665) elements • taskref (p. 1666) elements • iframe (p. 1666) elements • eval (p. 1685) statements → eval (p. 1685) statements

Document Element • simulation-wizard (p. 1655)

simulation-wizard Identifies the start of a TaskML file. <simulation-wizard version=»1.0″>

Attributes version Specifies the version of the TaskML vocabulary. The current version is «1.0.»

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Element Information Parents

None. This is the document element (root) of the XML structure.

Children

Merge (p. 1656), Script (p. 1656), object-groups (p. 1658), statuses (p. 1660), strings (p. 1661), tasks (p. 1663), body (p. 1664)

End Tag

Required

External References • Merge (p. 1656) • Script (p. 1656)

Merge Merges an external TaskML file. <merge src=»url» />

Attributes src Specifies the URL of the TaskML file to merge. Table 108: Element Information Parents

simulation-wizard (p. 1655)

Children

None

End Tag

No — close element with «/>»

See Also About the TaskML Merge Process (p. 1652) and URI Address and Path Considerations (p. 1650).

Script Specifies an external JScript file to load into the Mechanical Wizard. <merge src=»url» />

Attributes src Specifies the URL of the JScript file to load.

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TaskML Reference Remarks • JScript files use the .js file extension. • Code in the JScript file outside of any function is evaluated immediately upon loading. • The eval element may directly call functions defined in the JScript file. Table 109: Element Information Parents

simulation-wizard (p. 1655)

Children

None

End Tag

No — close element with «/>»

See Also URI Address and Path Considerations (p. 1650).

Object Grouping • object-group (p. 1657) • object-groups (p. 1658) • object-type (p. 1658)

object-group Organizes objects by placing them in an assigned group.

Attributes name Specifies the name of the group.

Element Information Parents

objectgroups (p. 1658)

Children

object-type (p. 1658)

End Tag

Required

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See Also object (p. 1671), select-first-object (p. 1680), select-all-objects (p. 1679), Standard Object Groups Reference (p. 1686).

object-groups Contains an unordered collection of object group definitions.

Element Information Parents

simulation-wizard (p. 1655)

Children

object-group (p. 1657)

End Tag

Required

See Also Standard Object Groups Reference (p. 1686).

object-type Specifies an Outline object by its internal identifiers.

Attributes class Identifies the class ID constant. type Identifies the type ID constant. Applies only for a class of «id_Load» or «id_Result.»

Remarks ID constants are defined in the script file DSConstants.js. The class attribute corresponds to the «Class» property of the Mechanical application objects. The type attribute corresponds the «loadType» or «ResultType» property of specific the Mechanical application objects.

Element Information Parents 1658

object-group (p. 1657)

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TaskML Reference Children

None

End Tag

No — close element with «/>»

See Also Standard Object Groups Reference (p. 1686).

Status Definitions • status (p. 1659) • statuses (p. 1660)

status Defines a task status. <status id=»statusID» css-class=»status-class» tooltip=»statusID_Tooltip» />

Attributes id Unique identifier for the status. css-class Specifies the class in the skin (cascading style sheet) to apply to the task. The style class defines the visual appearance of task status. tooltip Optional. Specifies the string ID of text to display in a tooltip when the cursor hovers over the task. Defaults to «statusID_Tooltip.»

Element Information Parents

statuses (p. 1660)

Children

None

End Tag

No — close element with «/>»

See Also set-status (p. 1684).

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statuses Contains an unordered collection of status definitions. <statuses>

Element Information Parents

simulation-wizard (p. 1655)

Children

status (p. 1659)

End Tag

Required

See Also set-status (p. 1684).

Language and Text • data (p. 1660) • language (p. 1660) • string (p. 1661) • strings (p. 1661)

data Data placeholder within a string. <string id=»stringID»>string textstring text

Remarks Used only with the Lookup method on a Strings object as defined in StringLookupObject.js. Allows JScript functions to retrieve a localized string containing arbitrary data.

Element Information Parents

string (p. 1661)

Children

None

End Tag

No — close element with «/>»

language Contains an unordered collection of strings in a specified language.

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TaskML Reference

Attributes xml:lang Specifies the language code. Defaults to «en-us» (English, United States).

Remarks The language code corresponds to the Language setting in the Wizard page of the Control Panel.

Element Information Parents

strings (p. 1661)

Children

string (p. 1661)

End Tag

Required

string Specifies the text for a given string ID. <string id=»stringID»>string text

Attributes id Unique identifier assigned to the string.

Element Information Parents

language (p. 1660)

Children

data (p. 1660)

End Tag

Required

strings Contains an unordered collection of languages. <strings>

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Element Information Parents

simulation-wizard (p. 1655)

Children

language (p. 1660)

End Tag

Required

Tasks and Events • activate-event (p. 1662) • task (p. 1663) • tasks (p. 1663) • update-event (p. 1664)

activate-event Contains a sequence of rules to process when the user clicks on a task.

Attributes tab Optional. Selects a specific tab before processing the activate event rules. design Selects the Design View tab. Default behavior if attribute omitted. print

Selects the Print Preview tab.

report

Selects the Report Preview tab.

help

Selects the Quick Help tab.

any

Does not change tab selection.

Element Information Parents

task (p. 1663)

Children

if, set-icon (p. 1684), set-caption (p. 1683), set-status (p. 1684), select-first-object (p. 1680), select-allobjects (p. 1679), select-field (p. 1680), select-first-undefined-field (p. 1682), select-first-parameterfield (p. 1681), select-zero-thickness-sheets (p. 1682), click-button (p. 1674), display-task-callout (p. 1677), display-outline-callout (p. 1675), display-details-callout (p. 1674), display-toolbar-callout (p. 1677), display-tab-callout (p. 1676), display-status-callout (p. 1676), open-url (p. 1678), display-help-topic (p. 1675), send-mail (p. 1682), eval (p. 1685), update (p. 1669), debug (p. 1667)

End Tag

Required

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TaskML Reference

task Defines a task.

Table 110: Attributes Attribute

Description

id

Arbitrary unique identifier assigned to the task.

caption

Optional. Specifies the string ID of the text to display in the task caption. Defaults to «uniqueID_Caption» if not specified.

tooltip

Optional. Specifies the string ID of the text to display in the task tooltip. Defaults to «uniqueID_Toolip» if not specified.

disable-if-missing

Optional. Disables the task if an object matching the group name does not exist.

hide-if-missing

Optional. Hides the task if an object matching the group name does not exist.

check-ambiguity

Optional. Automatically tests for ambiguity of an outline level prior to processing event rules.

icon

Optional. Specifies the URI of an image to use as the task icon. See URI Address and Path Considerations.

deemphasize

Optional. Causes a task inside an emphasized group to render with a deemphasized style.

Table 111: Element Information Parents

tasks (p. 1663)

Children

update-event (p. 1664), activateevent (p. 1662)

End Tag

Required

Also See: taskref

tasks Contains an unordered collection of task definitions.

Element Information Parents

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task (p. 1663)

End Tag

Required

update-event Contains a sequence of rules to process when the user navigates or modifies information in the Mechanical application.

Element Information Parents

task (p. 1663)

Children

if, set-icon (p. 1684), set-caption (p. 1683), set-status (p. 1684), select-first-object (p. 1680), select-allobjects (p. 1679), select-field (p. 1680), select-first-undefined-field (p. 1682), select-first-parameterfield (p. 1681), select-zero-thickness-sheets (p. 1682), click-button (p. 1674), display-task-callout (p. 1677), display-outline-callout (p. 1675), display-details-callout (p. 1674), display-toolbar-callout (p. 1677), display-tab-callout (p. 1676), display-status-callout (p. 1676), open-url (p. 1678), display-help-topic (p. 1675), send-mail (p. 1682), eval (p. 1685), debug (p. 1667)

End Tag

Required

Wizard Content • body (p. 1664) • group (p. 1665) • iframe (p. 1666) • taskref (p. 1666)

body Specifies content to display inside the Mechanical Wizard.

Attribute title Optional. Specifies the string ID of text to display in the title of the panel containing the Mechanical Wizard. Defaults to the text «Mechanical Wizard.»

Element Information Parents

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TaskML Reference Children

group (p. 1665), eval (p. 1685)

End Tag

Required

group Defines a collapsible group of tasks or iframes.

Attributes id Arbitrary unique identifier assigned to the group. caption Optional. Specifies the string ID of the text to display in the group caption. Defaults to «uniqueID_Caption» if not specified. description Optional. Specifies the string ID for a brief paragraph to display at the top of the group. Defaults to «uniqueID_Description» if not specified. If the string ID is undefined the group contains no description. emphasize Optional. Emphasizes the group via different visual styles. Defaults to «no.» collapsed Optional. Initially displays the group collapsed. After first use the collapsed status of each group is persisted. Defaults to «no.» onupdate Optional. JScript expression to evaluate on the Update event prior to processing the update-event (p. 1664) rules for tasks the group contains.

Element Information Parents

body (p. 1664)

Children

taskref (p. 1666), iframe (p. 1666), eval (p. 1685)

End Tag

Required

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iframe Inserts an HTML IFRAME element within a group. The IFRAME may contain any arbitrary web page and may communicate with the Mechanical Wizard via script. <iframe src=»uri» />

Attributes src Specifies the URI of the web page to load into the IFRAME. See the topic on IFRAME Elements for notes on security restrictions. Table 112: Element Information Parents

group

Children

None

End Tag

No — close element with «/>»

See Also Using IFRAME Elements (p. 1653).

taskref Inserts a task into a group.

Attributes task Specifies the ID of a task defined elsewhere in the merged TaskML file.

Element Information Parents

group (p. 1665)

Children

None

End Tag

No — close element with «/>»

See Also task (p. 1663).

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TaskML Reference

Rules • Statements (p. 1667) • Conditions (p. 1670) • Actions (p. 1673)

Statements • and (p. 1667) • debug (p. 1667) • if then else stop (p. 1668) • not (p. 1669) • or (p. 1669) • update (p. 1669)

and Performs a logical conjunction on two conditions. Equivalent to the JScript && operator. condition1

condition2

Element Information Parents

if

Children

Conditions: level (p. 1671), object (p. 1671), changeable-length-unit (p. 1670), assembly-geometry (p. 1670), geometry-includes-sheets (p. 1670), zero-thickness-sheet (p. 1672)Actions: select-firstobject (p. 1680), select-all-objects (p. 1679), select-field (p. 1680), select-first-undefined-field (p. 1682), select-first-parameter-field (p. 1681), select-zero-thickness-sheets (p. 1682), eval (p. 1685)

End Tag

Required

debug Attempts to launch a script debugger to debug the JScript code corresponding to the rules in the current event. Equivalent to the JScript debugger keyword. <debug />

Element Information Parents

update-event (p. 1664), activate-event (p. 1662), then, else

Children

None

End Tag

No — close element with «/>»

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if then else stop Conditionally processes a sequence of rules, depending on the value of a condition.

condition rules <stop/> <else> rules <stop/>

Remarks eval (p. 1685) statement. The not (p. 1669) operator negates the value of a condition. The and (p. 1667) and or (p. 1669) operators perform logical operations on two conditions within an if statement. The then statement contains a sequence of rules to process when the resolved value of the condition is true. An if statement must contain one then statement. The else statement contains a sequence of rules to process when the resolved value of the condition is false. The else statement is optional. If used it must follow the close of the then statement. The if…then…else structure is equivalent to the if…else statement in JScript: if( condition ) { statements } else { statements }

The stop statement ends processing of an event at a specific point. If a stop statement is not included within a then or else statement, rules following the if statement are processed. The stop statement is equivalent to the JScript return statement.

Element Information for

Parents

update-event (p. 1664) and activate-event (p. 1662)

Children

Operators: and (p. 1667), or (p. 1669), not (p. 1669) Conditions: level (p. 1671), object (p. 1671), changeablelength-unit (p. 1670), assembly-geometry (p. 1670), geometry-includes-sheets (p. 1670), zero-thicknesssheet (p. 1672) Actions: select-first-object (p. 1680), select-all-objects (p. 1679), select-field (p. 1680), select-first-undefined-field (p. 1682), select-first-parameter-field (p. 1681), select-zero-thicknesssheets (p. 1682), eval (p. 1685)

Element Information for

and <else> Parents

if

Children

set-icon (p. 1684), set-caption (p. 1683), status (p. 1659), select-first-object (p. 1680), select-all-objects (p. 1679), select-field (p. 1680), select-first-undefined-field (p. 1682), select-first-parameterfield (p. 1681), select-zero-thickness-sheets (p. 1682), click-button (p. 1674), display-task-callout (p. 1677), display-outline-callout (p. 1675), display-details-callout (p. 1674), display-toolbar-callout (p. 1677), display-tab-callout (p. 1676), display-status-callout (p. 1676), open-url (p. 1678), display-help-topic (p. 1675), send-mail (p. 1682), eval (p. 1685), update (p. 1669), debug (p. 1667)

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TaskML Reference End Tag

Required

not Performs logical negation on a condition. Equivalent to the JScript ! operator. <not> condition

Element Information Parents

if

Children

Conditions: level (p. 1671), object (p. 1671), changeable-length-unit (p. 1670), assembly-geometry (p. 1670), geometry-includes-sheets (p. 1670), zero-thickness-sheet (p. 1672) Actions: select-firstobject (p. 1680), select-all-objects (p. 1679), select-field (p. 1680), select-first-undefined-field (p. 1682), select-first-parameter-field (p. 1681), select-zero-thickness-sheets (p. 1682), eval (p. 1685)

End Tag

Required

or Performs a logical disjunction on two conditions. Equivalent to the JScript || operator. condition1

condition2

Element Information Parents

if

Children

Conditions: level (p. 1671), object (p. 1671), changeable-length-unit (p. 1670), assembly-geometry (p. 1670), geometry-includes-sheets (p. 1670), zero-thickness-sheet (p. 1672) Actions: select-firstobject (p. 1680), select-all-objects (p. 1679), select-field (p. 1680), select-first-undefined-field (p. 1682), select-first-parameter-field (p. 1681), select-zero-thickness-sheets (p. 1682), eval (p. 1685)

End Tag

Required

update Forces an Update event to fire. In general, this statement is necessary only if preceding rules in the event cause the status of other tasks to become out of sync.

Element Information Parents

activate-event (p. 1662), then, else

Children

None

End Tag

No — close element with «/>»

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Conditions • assembly-geometry (p. 1670) • changeable-length-unit (p. 1670) • geometry-includes-sheets (p. 1670) • level (p. 1671) • object (p. 1671) • zero-thickness-sheet (p. 1672)

assembly-geometry Tests if the geometry in context of the current selection contains an assembly or a single part.

Element Information Parents

if, and (p. 1667), or (p. 1669), not (p. 1669)

Children

None

End Tag

No — close element with «/>»

Return Value

True if the geometry contains an assembly.

changeable-length-unit Tests if the geometry in context of the current selection does not explicitly specify a length unit (e.g. for ACIS geometry types). Useful in prompting the user to verify a correct length unit setting.

Element Information Parents

if, and (p. 1667), or (p. 1669), not (p. 1669)

Children

None

End Tag

No — close element with «/>»

Return Value

True if the length unit is not readonly.

geometry-includes-sheets Tests if the geometry in context of the current selection contains sheet parts.

Element Information Parents

if, and (p. 1667), or (p. 1669), not (p. 1669)

Children

None

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TaskML Reference End Tag

No — close element with «/>»

Return Value

True if the geometry contains one or more sheets.

level Tests the level of the current selection in the Outline.

Attributes type Identifies the level. A level consists of a container (e.g., the Environment) and all children excluding other containers. condition Specifies a condition to test. is-ambiguous

Returns true if a specific container cannot be resolved given the current Outline selection.

is-not-ambiguous

Returns true if a specific container is identified given the current Outline selection.

is-selected

Returns true if any object at the given level is currently selected.

is-not-selected

Returns true if no object at the given level is currently selected.

Element Information Parents

if, and (p. 1667), or (p. 1669), not (p. 1669)

Children

None

End Tag

No — close element with «/>»

Return Value

As defined by the condition attribute.

object Tests the Outline tree for an object matching the given criteria. Searches only non-ambiguous objects given the current selection.