You could do a Combine.
Do you really need all of those solid bodies for the FEA (my guess is that some do not substantially influence the FEA (other than to increase processing time).
Can you attach example file here along with the FEA parameters.
Looks like the data translated too sloppy so I have to model from scratch... Thanks for the response!
just to add to this:
1. you don't need to combine unless you have simulationxpress that only supports single bodies/parts
2. solidworks recognizes assemblies the same as multibody parts
3. when running simulations on imported bodies, make sure to run import diagnostics and fix any issues before you add any features