Studies on rate-dependent switching effects of piezoelectric materials using a finite element model

The main goal of this paper consists in the modeling of rate-dependent behavior of piezoelectric materials within a three-dimensional finite element setting. We propose a rate-dependent polarization framework which is applied to cyclic electrical loading at various frequencies. The reduction in free energy of a grain is used as a criterion for the onset of the domain switching process. Nucleation in new grains and propagation of the domain walls during domain switching is modeled by a linear kinetics theory. Averaging over all individual grains renders the macroscopic response of the bulk material. Intergranular effects, which are essential for realistic simulations, are phenomenologically captured via a probabilistic approach. The presented numerical examples, as based on the proposed three-dimensional finite element framework, are related to the simulation of PIG 151 ceramics. In particular, averaged electric displacement versus electric field curves are plotted and compared with experimental data reported in the literature. (c) 2005 Elsevier B.V. All rights reserved.