Propagation of love-type waves in piezoelectric layered systems of cubic crystals with interfacial imperfections

Propagation of Love-type waves in piezoelectric layered structure consisting of a piezoelectric cubic crystal and an elastic substrate is studied. The interface between the two constituents is assumed to be mechanically compliant and dielectrically weakly conducting. The upper surface of the layered system is subjected to two kinds of boundary conditions, i.e. the electrically open and electrically shorted. The dynamic equations and the constitutive relations of piezoelectric cubic crystals with different cut orientations are firstly derived. The dispersion relations for the electrically open or short circuits are obtained by taking into account of the mechanical and electrical imperfections. The influences of interfacial imperfections, electrical boundary conditions and cut angles of piezoelectric cubic crystals on phase velocities are illustrated through numerical examples. It is found that the phase velocity for the electrically open case is slightly larger than that for the electrically shorted case. The mechanical imperfection has a great effect on the dispersion curves and then lowers the phase velocities, while the electrical imperfection makes the phase velocities larger. Moreover, the dispersion relations are more sensitive to the mechanical imperfection compared with the electrical imperfection.