I need to do FEA for 2 circular mating parts (One circular part seated in a pocket/counterbore in the another part). I have following questions:

1. i have to simulate no pentration contacts between the parts. Can i give Global no penetration component contact or should i individually give No pentration contacts set between the touching faces. Which approach is better.

2. Gap between the outer dia. of one part and inner dia. of another part is .015". I am not very sure if these two faces will touch each other under the action of applied load.Should i contacts at the non touching faces??

Thanks in advance

Sandeep