Multiple piezoceramic transducers (PZT)-structure interaction model

Abstract

Piezoceramic (PZT) transducers are extensively used for damage detection in electromechanical impedance (EMI) based structural health monitoring (SHM) of engineering systems. In the EMI methods, the PZT transducers are generally surface bonded or embedded inside the host structure, and then subjected to actuation so as to interrogate the structure for the desired frequency range. The interrogation results in the prediction of electro-mechanical admittance signatures. These signatures serve as indicator of the health/integrity of the structure. The existing PZT-structure interaction models consider the PZT transducer to be negligible in mass and thus ignored it. However, for multiple PZT-structure interaction, influence of the PZT mass becomes significant as there is significant increase in the number of PZT transducers. This paper presents a novel semi-analytical multiple PZT-structure interaction model which considers the mass influence of the multiple PZT transducers. The model involves numerical modelling, modal analysis and analytical formulation of admittance signature, and thus, is semi-analytical in nature. The numerical analysis serves to obtain the structure response for use as input to the analytical equations, so as to finally predict the admittance signature. The transducers and their host structure without restricting the PZT transducers to square shaped and electrically isotropic ones. Hence, it is expected to be applicable for the non destructive evaluation (NDE) of most engineering systems. The derived model is then experimentally verified using lab sized aluminium plate.