A theoretical study of the coupling effects in piezoelectric ceramics

Abstract

The objective of this study is to delineate electro-mechanical coupling in piezoceramic materials. The model system investigated is a two-dimensional linear piezoceramic strip polarized in the thickness direction, and it is subjected to local symmetric pressures on the upper and lower edges, traction-free boundary conditions on both end surfaces, and voltages on portions of the upper and lower edges. Under a simplifying assumption of the gradient of the electric potential, closed form solutions of the elastic field have been obtained. It is noticed that instead of the nine constants (including the elastic compliance constants, s i j , the piezoelectric constants, d i j , and the dielectric permittivity constants, ε i j ) , the elastic and piezoelectric characteristics of the material can be represented by three parameters, β 1, β 2 and β 3. β 1 consists of elastic compliance constants only. β 2 and β 3 signify the piezoelectric effect. Furthermore, higher values of β 2 imply a more pronounced piezoelectric effect on the elastic field. The identification of these parameters greatly facilitates the study of coupling effects in piezoelectric ceramics.