Claudio Pedrazzi
Subscriber

if you are looking for the natural frequencies, the "vibrating motor" at 16 Hz is not important. Just use a modal analysis system from Workbench, constrain the surfaces or points that are physically constrained and let the analysis run. If the analysis will give modes with frequencies of zero, or numerically zero, that will mean you have "free" parts in your assembly, that need to be correctly connected.