As a first step to a larger study, I am trying to do a simple FEA of a point contact between two spheres in contact using Pro/E Mechanica (version 4.0 I believe). I cannot get it to run. I do have some experience running FEA on single parts, but not assemblies. I am simply trying to force two spheres together (point contact) and observe the deflection (i.e. mutual attraction) of the two bodies for a given force. I don't have it in front of me right now, but I remember it was saying there was no interface defined (or something to that effect); I tried defining an interface and it didn't seem to fix it. Any help on how I can do this problem would be very greatly appreciated. Thanks.