Autodesk Nastran is a very easy-to-use add-on for Inventor that provides wide-ranging, reliable simulation functionality for multi-disciplinary analysis. Nastran In-CAD is fully integrated within your familiar Inventor (or Solidworks) environment. 

Partly thanks to this integrated workflow, Nastran In-CAD streamlines your entire design process, maximising your productivity and minimising compatibility problems.

When you purchase a licence for Autodesk Product Desing Collection 2018, you also have the right to use Nastran In-CAD 2015. This is the only way, in the new licensing structure, to "buy" Nastran In-CAD 2015 (further information on licensing).