Rayleigh Waves in an Electroelastic Medium with Prestressed Inhomogeneous Coating

Abstract

An approach to studying the influence of initial mechanical stresses and an electrostatic field on the structure and behavior of Rayleigh waves in piezoelectric media with nonhomogeneous coatings is proposed. This paper considers two-component coatings made of functionally graded piezoelectric material with high-speed (the speed of the shear-wave inclusion is greater than the speed of the shear wave in the substrate) or low-speed (the speed of the shear-wave inclusion is less than the speed of the shear wave in the substrate) inclusions. The initially deformed state of the coating is induced by the separate or combined action of the initial mechanical stresses and external electrostatic field. The influence of the type of non-homogeneity and the nature of the initial mechanical stresses in the presence or absence of an initial electrostatic field on the features of Rayleigh wave propagation for problems with an electrically open or shorted surface is studied. It is established that the presence of a low-intensity initial electrostatic field only slightly affects the action of the initial mechanical stresses depending on its direction. The presence of a high-intensity electrostatic field leads to additional deformation of the material, significant changes in the speeds of the SAW modes, and substantial changes in the structure of the surface-wave field. The obtained results are presented in dimensionless parameters and may be of practical interest in the development, design, and optimization of new materials for micro- and nanoscale devices and devices on Rayleigh surface acoustic waves with high performance characteristics.