Constitutive modelling of rate-dependent domain switching effects in ferroelectric and ferroelastic materials

In this contribution, a micro-mechanically motivated constitutive model for rate-dependent domain switching effects is studied. The main focus consists in the development of a three-dimensional finite element framework capturing phase-transformations, whereby for the sake of simplicity each finite element will represent one individual grain. For the investigation of phase-transitions, the onset of so-called domain switching processes is initiated by means of an energy-based criterion. During such switching processes, nucleation and propagation of domain wall motion is incorporated via a straightforward volume fraction concept combined with a simple linear kinetics theory. Moreover, grain boundary effects are accounted for, whereby a macro-mechanically motivated probabilistic approach has been chosen. Based on the proposed formulation, representative simulations are elaborated which provide further insight into the highly nonlinear behaviour of ferroelectric and ferroelastic materials.