Micromechanical modeling and simulation of rate-dependent effects in ferroelectric polycrystals

作者：Arockiarajan A; Sansour C^*

来源：Computational Materials Science, 2008, 43(4): 842-854.

DOI：10.1016/j.commatsci.2008.01.073

• Ferroelectrics
• Rate-dependency
• Intergranular effects
• Finite element formulation

In this contribution, rate-dependent switching effects of ferroelectric materials are studied by means of a micromechanically motivated approach. The onset of domain switching is thereby initiated based on the reduction in Gibbs free energy by means of energy-based criterion. The subsequent nucleation and propagation of domain walls during switching process are incorporated via a volume fraction concept combined with a simple linear kinetics theory. The key aspect in modeling of the interaction between the individual grains (intergranular effects) are incorporated in this model by making use of a probabilistic ansatz; to be specific, a phenomenologically motivated Weibull distribution function is adopted. The developed framework is incorporated into a finite element formulation whereby each domain is represented by a single finite element and initial dipole directions are randomly oriented so that the virgin state of the particular bulk ceramics of interest reflects an un-poled material. Based on a staggered iteration technique and straightforward volume averaging concept, the model is simulated to capture the non-linear behavior for different loading, for various loading amplitudes and frequencies. Attributes of the model, both symmetric major loops and biased minor loops are illustrated through examples. Simulation results for the rate-independent case are in good agreement with experimentally measured data reported in the literature and, moreover, are extended to rate-dependent computations which captures some important insights.

• 出版日期2008-10