FEM Tutorial Python

Introduction
This example is meant to show how a simple Finite Element Analysis (FEA) in FreeCADs FEM Module is done by python. The model from FEM_CalculiX_Cantilever_3D will be taken for this example.



Requirements

 * FreeCAD version → according tutorial overview
 * This could be checked at the menu Help → about FreeCAD.
 * Al thought due to the continuing changes in FEM module it is recommended to use the latest development snapshot of FreeCAD for python scripted FEM analysis's.
 * A set up FEM module. Check FEM_CalculiX_Cantilever_3D

FEM mesh
see Additional informations for how to script mesh generation with GMSH or Netgen mesh object.

Some informations
To run the analysis by Python an instance of the ccxtools module needs to be created. With this instance all processes could be done at once or step by step. If there is only one analysis in the document and only one solver in the analysis, no objects need to be passed on fea init. The init method of the fea class will activate the analysis if the gui is up. As an aditional information, activating an analysis by Python works a follows.

Scripting FEM mesh objects
Scripting the Netgen mesh object was tried here: http://forum.freecadweb.org/viewtopic.php?f=18&t=16944#p134519, but has some limitations. On the contrary the GMSH mesh object fully supports python scripting. See forum topic http://forum.freecadweb.org/viewtopic.php?f=18&t=20087

Scripting multiple analysis
See forum post: http://forum.freecadweb.org/viewtopic.php?f=18&t=19549#p151385

Scripting results
See forum posts:
 * https://forum.freecadweb.org/viewtopic.php?f=18&t=34048&p=289519#p289519 → scale factor in standard result object
 * http://forum.freecadweb.org/viewtopic.php?f=18&t=4677&start=20#p148982
 * http://forum.freecadweb.org/viewtopic.php?f=18&t=4677&start=30#p149043
 * http://forum.freecadweb.org/viewtopic.php?t=18415#p144028
 * https://forum.freecadweb.org/viewtopic.php?f=18&t=31123&p=258761#p258761 → coloring just one element
 * https://forum.freecadweb.org/viewtopic.php?f=18&t=41951&p=357687#p357685 → reset all result mesh, show colored displacement magnitude

Console mode
Writing the input file in FreeCAD console mode (no Gui) could be done in test mode. See forum post in this regard: https://forum.freecadweb.org/viewtopic.php?f=22&t=25852&p=208897#p208897

Appendix
Have Fun!