SH Surface Waves in Functionally Gradient Piezoelectric Material Plates

Abstract

The numerical methods which have been proposed by the present authors for investigating the characteristics of waves in a functionally gradient piezoelectric material (FGPM) plate and its transient responses are used to investigate SH waves in FGPM plates. The material properties of the plate change gradually with the thickness of the plate. To evaluate the properties of the energy transfer between the electrical and mechanical energies during acoustic wave propagation in dispersive media, an electromechanical coupling constant is defined on the basis of group velocities of the acoustic waves. Numerical examples are given for a hypothetical FGPM plate and a homogeneous plate. It is found that there are SH surface waves propagating on the softer surface of the FGPM plate. Furthermore, for waves in dispersive media, the electromechanical coupling constant based on group velocities is found to be much better than that based on phase velocities.