Dispersive characteristics of sh surface waves in semi-infinite magneto-electro-elastic layered periodic structures

By the transfer matrix method, dispersive characteristics of the shear horizontal (SH) surface waves in semi-infinite piezoelectric(PE)/elastic(EL)/piezomagnetic(PM) and PM/EL/PE layered periodic structures are investigated. The free surface is parallel to the layer interfaces. Both PE and PM materials are transversely isotropic. The effects of different electric-magnetic boundary conditions at the free surface on the dispersion curves have been discussed. For comparison, band structures for the SH bulk waves in corresponding infinite periodic media are presented. Numerical results show that dispersion curves of the SH surface waves are inside the frequency gaps. The electric/magnetic conditions dominate the dispersive characteristics of the surface waves for the PE/EL/PM and PM/EL/PE structures, respectively. The frequency band structures for SH bulk waves are consistent for these two structures.