Love waves in piezoelestric layered structure with functionally graded materail half space

In this theoretical study, we investigate the propagation of Love waves in a piezoelectric layered structure. The substrate of the layered structure is a functionally graded material (FGM) in which parameters vary along thickness and in the bounded domain. Both variable substitution and power series technique, which are shown to have good convergence and high precision, are employed for the asymptotic analytical derivations of the governing equation of Love wave. The influence of the gradient coefficient of FGM on the dispersion curves, and electro-mechanical coupling factor, and the displacement amplitude distributions of Love waves in this structure are investigated. The theoretical results set guidelines not only for the design of high performance surface acoustic waves (SAW) devices using the FGM substrate, but also for the measurement of material properties of FGM half space using Love waves.