Characterization of Polarized Shear Waves in FGPM Composite Structure with Imperfect Boundary: WKB Method

Abstract

Propagation behavior of horizontally polarized shear waves (SH-waves) in a piezo-composite structure is discussed, using the Wentzel–Kramers–Brillouin (WKB) method. The considered model is made by combining the Functionally Graded Piezoelectric Material (FGPM) layer and piezoelectric orthotropic substrate. The linear form spring model is considered to delineate the imperfection of interface. Moreover, the material properties of FGPM layer are varying linearly along the thickness direction. Dispersion relation is obtained for both electrically open and short cases. Numerical example and graphical representation have been provided to illustrate the effect of different parameters on the phase velocity of SH-waves. As a special case, dispersion relation has been obtained when the boundary is perfect. Results are compared for different orthotropic materials to add more specific observations. Finally, the outcome of this study is validated by matching it with classical Love wave result. Observations will be helpful in optimization of Love wave sensors and Surface Acoustic Wave (SAW) devices.