Natural frequencies of submerged piezoceramic hollow spheres

An exact 3D analysis of free vibration of a piezoceramic hollow sphere subm erged in a compressible fluid is presented in this paper. A separation meth od is adopted to simplify the basic equations for spherically isotropic pie zoelasticity. It is shown that there are two independent classes of vibrati on. The first one is independent of the fluid medium as well as the electri c field, while the second is associated with both the fluid parameter and t he piezoelectric effect. Exact frequency equations are derived and numerica l results are obtained.