Domain switching effects on crack propagation in ferroelectrics through SBFEM

Abstract

Electromechanically coupled ferroelectric materials exhibit complex nonlinear behaviour under higher magnitudes of mechanical and electrical loading owing to their microscopic domain switching phenomenon. The presence of pre-cracks in the polycrystalline ferroelectrics intensifies the localized electric fields and mechanical stresses. In this paper, a micromechanical model combined with the scaled boundary finite element method (SBFEM) explores domain switching near the crack tip under cyclic electric fields and mechanical stresses. The solution for stress at the singularity near the crack tip is realized through SBFEM. A naturally evolving Voronoi polygonal tessellation is employed to mimic the microstructure of a typical polycrystalline ferroelectric material where each ferroelectric grain is represented by a Voronoi polygon. The dynamic crack propagation across grains under electrical or combined mechanical loading is predicted by introducing a novel re-meshing technique. The fracture parameters evaluated through the proposed method are validated by their close correspondence with the experimental compact tension test and three-point bend test results from the literature.