The ABRAVIBE example ForcedResponse is illustrating the power of the digital filter forced response method for computing forced response developed by Kjell Ahlin and published in, among other references, “Noise and Vibration Analysis: Signal Analysis and Experimental Procedures,” by Anders Brandt. The method uses a modal superposition formulation using
a ramp invariant transform to formulate the forced response of each mode. Also see inside the ABRAVIBE command timefresp for references to original papers.
The example produces time data simulating a measurement of 35 displacement responses on a Plexiglass plate, when it is excited with four forces in the corners of the plate. Mode shapes and eigenfrequencies from a finite element model are used as a model for the plate.