Laminated piezoelectric phononic crystal with imperfect interfaces

Dispersive characteristics of elastic waves propagating through laminated piezoelectric phononic crystal with imperfect interfaces are studied in this paper. First, the transfer matrix method and the Bloch theorem are used to derive the dispersion equation. Next, the imperfect interfaces with the jump of mechanical quantity across interface are considered. In the spring model of imperfect interface, the tractions are continuous, but displacements are discontinuous across the interface. In the mass model of imperfect interface, displacements are continuous, but tractions are discontinuous. In the spring-mass model, both traction and displacement are discontinuous. The effect of imperfect interface is introduced by inserting an additional interface transfer matrix in the calculation of total transfer matrix. Finally, the dispersion equation is solved numerically and the dispersive curves are shown in the Brillouin zone. Band gaps of phononic crystal with imperfect interface are compared with that of phononic crystal with perfect interface. The influences of the imperfect interface on the dispersive curves and the band gaps of periodic laminated piezoelectric composite are discussed. (C) 2012 American Institute of Physics. [doi: 10.1063/1.3672404]