FEM CalculiX Cantilever 3D/ru

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This page is a translated version of the page FEM CalculiX Cantilever 3D and the translation is 9% complete.

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Введение

Этот пример предназначен для того, чтобы показать, как выглядит простой анализ методом конечных элементов (МКЭ/FEA) во FreeCAD FEM Module и как можно визуализировать результаты. Показано, как запустить (МКЭ) и как изменить значение нагрузки и направление нагрузки. Более того, поскольку файл примера предоставляется при любой установке FreeCAD, легко проверить, правильно ли установлен модуль FEM.

FEM example01 pic00.jpg

Требования

  • FreeCAD версия = 0.16.6377 или выше.
  • Это можно проверить в меню Справка -> о FreeCAD. Номер редакции должен быть больше 6377
  • Не требуется никакого внешнего программного обеспечения для загрузки файла примера, просмотра сетки и геометрии, а также для визуализации результатов.
  • Для повторного запуска FEA на вашем компьютере должно быть установлено программное обеспечение CalculiX. Возможно, решатель уже установлен вместе с FreeCAD. Если решатель CalculiX не установлен, см. FEM Install.

Set up the example file

Load Start Workbench

  • Start FreeCAD
  • The Start Workbench should be loaded

Load the example file

  • Go to the example projects and click on "Load an FEM analysis example"
  • If due to further operations some geometry, constraints or the results are broken or deleted just repeat the steps above.

FEM example01 pic01.jpg


Activate the analysis container

  • To work with an analysis the analysis has to be activated.
  • In tree view right click on the FEM Analysis.png MechanicalAnalysis → Activate analysis

FEM example01 pic02.jpg


Analysis container and its objects

  • If the analysis is activated FreeCAD itself will change the current workbench to FEM.
  • There are at least the 5 objects needed to make an static mechanical analysis.
  • FEM Analysis.png analysis container
  1. FEM Solver.png a solver
  2. FEM Material.png a material
  3. FEM FixedConstraint.png a fixed constraint
  4. FEM ForceConstraint.png a force constraint
  5. FEM Create.png a FEM mesh
  • Since in the example here the results are included as well there is a sixth object, the results FEM ShowResult.png.


Visualizing Results

  • Be sure the analysis is activated.
  • Be sure the analysis still contains the result object, if not just reload the example file.
  • Click in icon toolbar on FEM ShowResult.png Show result
  • In task window choose z-Displacement. It shows -88.443 mm in negative z-direction.
  • This makes sense since the force is in negative z-direction as well.
  • Activate the check box besides the bottom slider of displacement show.
  • The slider can be used to alter the mesh to view the deformation in a simplified manner.
  • Choose among the different Result types to view all in the GUI available result types.

FEM example01 pic03.jpg


Purging Results

  • Be sure the analysis is activated.
  • To remove the results select in the icon toolbar FEM PurgeResults.png Purge results

Running the FEA

  • In Tree view double click on the solver object FEM Solver.png.
  • In task window of the solver object make sure static analysis is selected.
  • Click on write .inp file in the same task window. Watch the log window until it prints "write completed."
  • Click on Run CalculiX. Since this is a very small analysis it should take less than a second to run.
  • In the text window it should print in green letters "CalculiX done!" and in the next line "loading result sets ..."
  • You just have finished your first FEA in FreeCAD if there has not been any error message.
  • Click on Close in the task window.
  • A new result object should be created. You know how to visualize the results already.
  • If you get an error message no solver binary or similar when triggering the analysis check FEM Install.

FEM example01 pic04.jpg

Running the FEA the fast Way

  • In tree view select the solver object FEM Solver.png of the analysis FEM Analysis.png.
  • In the icon toolbar click on FEM RunCalculiXccx.png Quick Analysis.
  • The Calculix input file will be written, CalculiX will be triggered and the result object should be created.

Changing Load Direction and Load Value

  • In tree view select the FEM mesh object FEM Create.png and press the space key.
  • The visibility of the FEM mesh will be turned off. The geometrical model is still visible.
  • In tree view double click on the force constraint object to open its task window.
  • In the task window change the load value to 500000000 N = 500 MN (force unit in task window has to be in N)
  • Click on Button Direction.
  • On the geometrical model click on on of the long edges in x-direction.
  • The red arrows of the force will change their direction in x-direction. They show to the fixed direction.
  • Since tension should be applied to the box the Reverse Direction needs to be triggered by clicking on it.
  • The red arrows of the force will change their direction.
  • Click on OK in task window.

FEM example01 pic05.jpg

  • Turn the visibility of the FEM mesh FEM Create.png on by selecting it in tree view and pressing the space key.
  • You know how to trigger an analysis and how to visualize results already.
  • The deformation in x-direction should be 19.05 mm.

FEM example01 pic06.jpg

Что дальше?

  • Теперь мы закончили с основным рабочим процессом для FEM Module.
  • Теперь вы готовы сделать второй FEM tutorial.
  • Мы создадим консоль CalculiX самостоятельно и сравним результаты с теорией пучка.