Calculix - Calculix is a free and open-source finite-element analysis application that uses an input format...
midas Gen - Structural Analysis and Design
elmer - Elmer is an open-source software package that solves partial differential equations. Combined with its ability to run various equations in parallel, it is an effective tool for running multiphysical simulations. Read more about elmer.
Robot Structural Analysis Professional - Structural Analysis and Design
FreeCAD - An open-source parametric 3D modeler
STAAD.Pro - Structural Analysis and Design.