Non linear effects in piezoelectric materials

The static and dynamic non-linear behaviours of a soft and a hard lead zirconate titanate composition were investigated as a function of electrical and mechanical fields. The calculated Rayleigh coefficients showed that they were similar for the permittivity and the piezoelectric constant and null for the voltage constant and the compliance at zero D (D = dielectric displacement). A non-linear electromechanical equivalent circuit was built up with components proportional to D. A model extended to non-Rayleigh type behaviours is proposed. 12 refs.