CHARACTERIZATION OF MECHANICAL VIBRATION DAMPING BY PIEZOELECTRIC MATERIALS

Piezoelectric materials (piezo-materials) convert mechanical energy in to electrical energy via the mechanism of piezoelectricity, and this e lectrical energy may be dissipated through a connected load resistance . The energy dissipation through this mechanism is termed piezo-dampin g. New models based on this energy conversion and dissipation have bee n proposed to characterize the damping behaviour of the piezo-material s. An equivalent electrical circuit model is put forward to determine the required load resistance, and a mechanical spring-dashpot model is used to describe the damping capacity of the piezo-materials. Equatio ns were derived to predict optimal resistance load, maximum damping ra tio and the shift of the resonance frequency. A two-degree-of-freedom (2-DOF) experimental set-up was developed to test the validity of the models. The experimental results agree very well with the theoretical predictions. The piezo-damping mechanism exhibits potentially a high d amping capacity. (C) 1996 Academic Press Limited