Hi Lara,

I didn't change anything in your contact parameters.  I only repaired the faces that were in the Skin and Helmet Named Selections as mentioned in a previous reply.

I did use Linear elements, but I should have been more specific. Linear Hex elements are the best for contact. Linear Tet elements are not recommended for stress analysis. I hadn't seen your geometry when I made that comment. With this kind of geometry, Quadratic Tets end up being used because it it too much work to hex mesh this geometry.