The Bleustein-Gulyaev (B-G) wave in a piezoelectric layered half-space

As to a layered half-space with identical piezoelectric layer and substrate but in opposite polarization, the expressions for the phase velocity equation of the Bleustein-Gulyaev (B-G) wave are obtained by analytical technique. It is found by numerical examples that the penetration depth of the BG wave is in the same order as the wavelength for a layered half-space, in the same time, the electromechanical coupling factor can still maintain quite high values for appropriate thickness of the layer. It is further discovered and proved in this paper that for a layered half-space with different piezoelectric layer and substrate, a peculiar kind of motion mode of the B-G wave can be achieved when their electrical character constants and the thickness of the layer are satisfied with certain relationship. When this peculiar kind of surface wave propagates, the transverse component of displacement of the particles can be found only in the layer and the displacement of the particles in the substrate is always zeros. The existing conditions of the above surface wave and its corresponding phase velocity equations are obtained. Several numerical results are also given. (C) 2001 Elsevier Science Ltd. All rights reserved.