SH Surface Waves in Functionally Gradient Piezoelectric Plates

抄録

The numerical method which has been proposed by the present authors for wave propagation analysis in functionally gradient piezoelectric material (FGPM) plates is 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, the electromechanical coupling constant based on group velocities is found to be more appropriate than that based on phase velocities for waves in dispersive media.