2-DIMENSIONAL MODEL FOR SHEAR PIEZOCERAMIC CHARACTERIZATION

This paper is devoted to the two-dimensional modelling of shear vibrat ion modes of a piezoceramic plate for assessing the influence of geome try on the parameter measurement. The two-dimensional model is based o n the assumption that a plane wave propagates along the cross-section diagonal of the sample. Using an exact equation of the electric potent ial inside the body, the shear displacement and electrical impedance o f the sample are determined. The theoretical impedance deduced from th e 2D modelling reduces to the well-known 1D constant D model when a mu ch greater than b. Computed results show that the measured electromech anical coupling factor depends on the length to thickness ratio b/a. T his result is consistent with experimental results.