A friend design a machine manufactured in welded steel plates, this machine was modeled in Solidworks 2013, creating all welded part and assembly. Subsequently, he developed studies stress and fatigue, using the Simulator Solidworks.

I've checked at the design. When I run the command "interferes detection" the result is 40 small interference in the assembly.

I have question, Is valid this study  FEA if the plates (part)  were overlapped in the model?