Cosmos Express-Viewing interior details?

I have a assembly of 2 plastic parts that I am sonic welding together to form a manifold assembly. I created a "joined" part, to allow analysis with Cosmos (1 part vs assembly). I have applied a pressure load, and want to examine resulting stresses. Works fine, but the problem is that my peak stresses seem to be on the inside surfaces of the part, as you would expect. Is there any way to do a section view on the Cosmos works stress distribution output? Or, failing that, is there any way to define symmetry within Express and do the analysis on

Thanks. Brian