Love waves in piezoelectric coupled solid media

The propagation of Love waves in a piezoelectric lamina bonded onto a semi-infinite solid medium is investigated in this paper. The dispersive characteristics and the mode shapes of the deflection and the electric potential in the thickness direction of the piezoelectric layer are theoretically derived. Numerical simulations show that the phase velocities initiate at the shear wave velocity of the host medium and tend towards the Bleustein-Gulyayev surface wave velocity for the piezoelectric layer at high wavenumbers for the first mode. The first two mode shapes of the electric potential correspond to a half-cosine and a full-cycle sinusoidal distribution, respectively, and become distorted as the wavenumber increases. These findings are significant in the application of inter-digital transducers for surface wave excitation in structural health monitoring.