Translations:FEM Install/20/en

From FreeCAD Documentation

The default solver to perform finite element calculations is CalculiX, a simple solver for analysis of structures. FreeCAD writes a CalculiX input file, starts the solver, and reads the output, which can then be presented visually in the viewport; this means the CalculiX binary is standalone and independent from FreeCAD. Given that there are many programs that can generate a mesh, it is recommended to install the solver, and make sure it's working first.