CalculiX Binaries for MS Windows, made with CYGWIN and ARPACK libraries. CalculiX is most popular FEA open-source package (like Code-Aster and Elmer-FEM). it is comparable in features with most known commercial packages like ANSYS, NASTRAN, Abaqus, etc. Good for structural, mechanical, thermal and fluid applications (trusses, plates, frames, shells, solid bodies). It has powerful nonlinear capabilities (including tension/compression only material like concrete) and most types of analysis (modal, thermal, buckling, coupled, etc) . See home page at http://www.dhondt.de
New versions can be obtauned here: http://calculixforwin.blogspot.com/2015/05/calculix-launcher.html
calculixforwin works great
Easy to install and use.