Design and Evaluation of Multi-Axis Vibration Shaker Concepts

Multi-axis shaker systems for the mechanical testing of components up to 2 kHz generally exhibit multiple resonances within their operating range of frequencies. Equipment testing requires the control of the shaker’s power density spectra in all axes of shaker motion. The paper describes the results of a 4-year ongoing project to develop a predictive model of 6-axis shaker dynamics, and presents a comparison between the computer model and a series of experiments on a small 6-DOF electrodynamic shaker, employing computed and experimentally recorded power density and coherence spectra, as well as modal analyses. Modifications of the shaker’s structural stiffness and damping are shown to be correctly predicted and validated by the experiments.