Hi @poornam07
When problems like this occur, one option is to mesh the model as shells (instead of solids). If a face cannot be meshed, a shell mesh will often mesh the rest of the model. Then you can see where the failure is occurring.
Oddly, this did not work. But I did find two surfaces that would not mesh as shells. The rest of the model will mesh as shells. I suggest you trim off the ends of the springs to eliminate the double curved geometry. (Although the opposite end did mesh, I would trim it off also.)
John
John Holtz, P.E. Global Product Support
Autodesk, Inc. If not provided already, be sure to indicate the version of Inventor Nastran you are using!"The knowledge you seek is at knowledge.autodesk.com" - Confucius 😉