Autodesk Fusion 360 Users

The FEA is Nastran (Fusion used as graphical interface).

You have to make test cases to check the accurency of the result.

The FE Solver is the old NEi Nastran, bought by Autodesk a few years ago. It's not exactly "Nastran" (the only two "real" Nastran alive are from MSC and Siemens, plus the old Cosmic version), but it's fairly decent for mildly complex things. Of course, it's semi-automated, so one needs to be careful about the results (element types, mesh convergence studies, ...) , but that's true of all solvers.