There are examples of using SOL 108 and SOL 111 to create a frequency response. In Siemens Simcenter (NX Nastran), the examples focus on a tower with a seismic mass. The model drives the mass with an acceleration, attaching the mass to the structure using rigid elements.
This creates a model that adds (?) stiffness at the mass attachment points.
What if I want to simulate the frequency response function (FRF) of a structure that is unconstrained?
The test I conducted was to hang my part on a wire and tap (laterally) it with an impulse hammer.
This might be equivalent to constraining the support point as:
- Fixed in DOF's 1, 2 (Tx and Ty)
I could apply a lateral acceleration (in the direction of the hammer tap).
Is this the conventional way to produce the FRF? If not, what is?