Propagation Behaviors Of SH Waves In Piezoelectric Layered Structures With An Imperfect Interface

Due to the capability of conversion between mechanical and electrical energy, piezoelectric materials have widely been used in technology as sensors, filters, transducers and actuators, and so on. These devices are commonly constructed in layered form and many applications of them are related to the knowledge of elastic wave propagation. Therefore, studies of the propagation of elastic waves accompanied by electrical waves have long been of interesting to researchers in the fields of applied physics, mechanics and acoustics.This dissertation deals with the propagation of shear horizontal (SH) waves in two kinds of layered structures consisting of piezoelectric and purely elastic media:one being the plane layered structure, and the other being the layered cylinder. The interface is assumed to be imperfect. Piezoelectric materials are transversely isotropic, while pure elastic materials are isotropic or orthotropic.The dispersion equations for the considered layered structures are derived and then the phase velocities are calculated for different material combinations. The numerical results show that:(a) In comparison with the case of the perfect interface, the imperfect degree of the interface reduces the phase velocities at the lower wave number. (b) When the wave number is lower and the imperfect degree of the interface is weaker, the phase velocities decrease as the ratio of the thickness of the piezoelectric layer to the purely elastic substrate or cylinder increases. (c) The difference between piezoelectric material properties has substantial influences on the dispersion characteristics, and their influences are reflected by velocities of the B-G surface wave and SH bulk wave. (d) For the piezoelectric half-space carrying a purely elastic orthotropic layer, the phase velocity decrease with the increase of the anisotropic degree. These findings may useful for improvement of piezoelectric devices or structures as well the experimental determination of interface property.