I assume these parts are steel.  Have you tried pushing on steel and getting it to move 0.5 mm. It takes an enormous force. Why did you choose 0.5 mm?  Try running a Static Structural model and see if you can statically deform the parts with a 0.5 mm displacement (or just make a 2 step solution in Transient Structural with time integration off in step 2). Maybe an interference of 0.05 mm or smaller would be more appropriate. Please reply with the reaction force from these two displacements.

Why did you choose a vibration frequency of 20 Hz?  What is the first natural frequency of this structure?  You should run a Modal analysis and see what that is.