Guided wave generation, sensing, and damage detection using in-plane shear piezoelectric wafer

Abstract

This work presents guided wave generation, sensing, and damage detection in metallic plates using in-plane shear ( d 36 type) piezoelectric wafers as actuators and sensors. The conventional Lead zirconate titanate (PZT) based on induced in-plane normal strain ( d 31 type) has been widely used to excite and receive guided wave in plates, pipes or thin-walled structures. The d 36 type of piezoelectric wafers however induces in-plane (or called face) shear deformation in the plane normal to its polarization direction. This form of electromechanical coupling generates more significant shear horizontal waves in certain wave propagation directions, whose amplitudes are much greater than those of Lamb waves. In this paper, an analysis of shear horizontal (SH) waves generated using in-plane shear electromechanical coupling is firstly presented, followed by a multiphysics finite element analysis for comparison purpose. Voltage responses of both conventional d 31 and new d 36 sensors are obtained for comparison purpose. Results indicate this type of wafers has potential for simply providing quantitative estimation of damage in structural health monitoring.