You can try DEFORM software for machining operations. Mesh regeneration will be important for you, and DEFORM will enable this requirement .However, it is not a open source software, though you can create your own material library via Fortran etc. and implement it to DEFORM.
Hulas, you should have a look at FreeCAD it is open source and as the name implies free. Joko engineering has run a direct comparison of FreeCAD against Solidworks for FEA and was impressed by the results himself. Which is most likely why he published the video on Youtube. Everyone should try it for the CAD modelling alone!
As bogdan alexandru mentioned Abaqus is available. Where you can solve any static, dynamic, nonlinear priblems. Also you can cide your own element... Wgich is most essential in fracture mechanics and crack growth analysis
You're definitely not allowed to use the student versions of ANSYS and ABAQUS for conducting researches and obviously also for commercial purposes. These versions are solely intended for students or (I'd guess) FEM amateurs with a lot of spare time. Please let us not confuse the ability to download a fully or partially working piece of software with the right to use it and publish results obtained from it. It's highly misleading.