and how use .step files in Hyperworks??
IGES and STEP are the widely used neutral CAD formats and accepted in all software. In IGES the output is in surfaces while STEP file keeps the assembly hierarchy and output is a mixture of solids/volumes and surfaces (only solids in most of the cases).
Link for importing .step file to Hyperworks : https://www.youtube.com/watch?v=LxH9atTeruM