Shear-Type Surface Waves In Piezoelectric Materials And Its Application In The Measurement Of Liquid's Properties

Surface waves have been applied successfully in many of the technological fields, such as NDE of materials, seismological exploration, and SAW devices in electronic industry. Besides Rayleigh waves and Love waves, due to the property of electromechanical coupling in the piezoelectric material, there exist surface waves called B-G (Bleustein-Gulyaev) waves in the crystal with the high symmetry level such as 6mm and mm~2. Because the energy concentrates in the surface of materials, propagation characteristics are sensitive to the variation of the material condition. By this characteristic, we can reckon the property of the viscous liquid by testing the change of surface waves'propagation characteristics.In this paper, by taking 6mm piezoelectric material loaded with viscous liquid as a physical object, the relation between the characteristics of B-G waves and the property of the viscous liquid is studied. With the derivation under different boundary conditions, we could get the relation between the coefficient of viscosity, density, shear modulus, conductivity of liquid, viscoelasticity liquid, electrolyte solution and the attenuation, frequency, wave velocity of B-G waves. And provide the foundation of theory and calculation for getting the characteristic parameters of liquid.