3-DIMENSIONAL MODELING OF A PIEZOELECTRIC CERAMIC DISK LOADED ON ITS MAJOR SURFACES

This paper is devoted to the modelling of a piezoceramic disk loaded o n its major surfaces by acoustic impedances denoted Z(a) and Z(b) resp ectively and using a three-dimensional approach. The stress, stain com ponents and the displacements along the radius and the disk thickness are determined which allows the calculation of the electric impedance of the loaded disk and the related electromechanical coupling factors. It is shown that, due to lateral couplings, the resonance peak width of the 3D modelling is larger than that obtained for ID models. Furthe rmore, due also to lateral couplings, there is no nodal plane inside t he disk. It becomes a zero-phase plane that is, the displacements corr esponding to this plane is minimal and the difference in phase related to the applied voltage is zero. This result is consistent with the pr evious finite element simulations.