Electromechanical coupling and mass loading sensitivity of SH waves in a dielectrically imperfect piezoelectric structure

Abstract

Imperfect mechanical or dielectric interfaces in piezoelectric sensors/actuators reduce the electromechanical efficiency of the system. The major drawback of an imperfect interface in a system is its disability to transfer stress or potential across the surface effectively. This leads to imperfect signal communication and thereby affecting its performance. The present study encapsulates the shear wave (Love wave in low velocity layer and B-G wave) propagation characteristics in an imperfectly bonded piezoelectric layered structure, also subjected to material gradients. The imperfect bonding interface is considered to be mechanically compliant and dielectrically weak (or high) conducting. With help of admissible, but non-traditional, boundary conditions at the interface, the dispersion equations of waves are derived by method of infinite determinants for both electrically open and shorted conditions at the free surface. Phase velocity, electromechanical coupling factor and mass loading sensitivity of shear waves are sketched graphically with special concern on the influence of interface imperfection on them. The results reported can serve to overcome the deficit in the performance of Love wave sensors due to mechanically/dielectrically imperfect interfacial surface.