Frequency-dependent open-circuit acoustic sensitivity offluid-filled, coated, radially polarized piezoelectric ceramiccylindrical shells of arbitrary thickness and infinite length

摘要

The frequency-dependent free-field open-circuit voltage generatednby radially polarized piezoelectric ceramic fluid-filled shells ofninfinite length coated with an elastic layer and excited by a planenacoustic wave is studied. The shell and the coating are of arbitrarynthickness and are anisotropic. It is shown that the charge density innthe piezoelectric shell is zero by using the electrostatic andnopen-circuit conditions. General expressions for the pressures andnradial velocities in the interior and exterior fluids are obtained bynusing the finiteness and radiation conditions, respectively. Generalnexpressions for the radial stresses and velocities in the piezoelectricnshell and elastic coating are also determined by using two-dimensionalnequations of state and axisymmetric equations of motion. Thencoefficients in the general expressions are then determined by using thencontinuity conditions at the various interfaces. Finally, an expressionnfor the open-circuit sensitivity is obtained by using a piezoelectricnequation of state. Numerical results are presented for air, water, andnvacuum in the interior, two types of elastic coating, and piezoelectricnshells with various thicknesses. The effect of neglecting anisotropy onnthe sensitivity is also illustrated