I'm trying to conduct a frequency analysis on a larger assembly and noticed that faces I had applied fixtures to were not working. I had applied fixed geometries to these faces but the simulation results showed that they would translate and rotate. The results were the same as if I didn't have any fixtures. I had 6 rigid body modes with frequencies close to 0Hz and the rest were modes as if the model was not constrained at all.
I have attached the solidworks part which seems to be the source of the problem. It is a sheet metal part. In the assembly it was in, I tried both fixed geometry and immovable fixtures but neither worked. I am a beginner so I'm wondering if there is some nuance that I am not privy to. Any help would be much appreciated. Thanks.