Finite-element modelling of ferroic domain switching in piezoelectric ceramics

Piezoelectricity in polycrystalline materials like PZT ceramics is a complex phenomenon of both linear and ferroic electromechanical coupling based on the single crystal piezoeffect and on domain switching, respectively. The latter can be caused by mechanical and/or electrical loading and yields to changes of the polarisation texture of the polycrystalline material. The ferroelastic and ferroelectric hystereses can be understood by means of a micromechanical model. In order to include the grain-to-grain interaction finite-element (FE) method is ifs own recommendation. The micromechanical model has been implemented into the FE code ANSYS (C) (SOLID 45). Furthermore the 3D piezoelectric element SOLID 5 has been extented to the nonlinear option. On the basis of these elements the mechanical and the electrical hystereses and the strain versus electric field curve have been modelled. Special attention has been directed to the asymmetry of tension and compression by comparing experimental and simulation results. (C) 1999 Elsevier Science Limited. All rights reserved.