Help with Modal analyses

I need some help with Pro/Mechanica. I am analyzing a wedge shaped chopper mounting block and I would like to do a Modal analysis using contact regions or free interfaces with a force pressing on the wedge. Since Modal analyses are only calculating the natural frequency of certain geometry, I think that Mechanica assumes everything is rigid. However in this instance I would like to see how the frequency changes with a varying preload, so I do not want Pro/E to assume the assembly is a solid part. Anyone with any ideas?

I need some help with Pro/Mechanica. I am analyzing a wedge shaped chopper mounting block and I would like to do a Modal analysis using contact regions or free interfaces with a force pressing on the wedge. Since Modal analyses are only calculating the natural frequency of certain geometry, I think that Mechanica assumes everything is rigid. However in this instance I would like to see how the frequency changes with a varying preload, so I do not want Pro/E to assume the assembly is a solid part. Anyone with any ideas?

I'm not sure if it assumes it is rigid or if it assumes it is static. That may seem like the same thing but it may also mean that you just need to measure modality with a mechanism in different positions. In any case, it definitely does not assume that an assembly is a single piece part. I'm sure you've assigned each a material and it is those material properties that are used in the calculations. It might be possible to consider an assembly a single part if each component is made of the same material that's heat treated in the same way, otherwise not. The only other circumstance in which it could treat the assembly as single part is if it were made from imported solid geometry which has lost its material properties.