Two-surface model of macroscopic electro-mechanical behavior for ferroelectrics under unaxial loading
铁电陶瓷宏观单轴力电行为的双面模型

Ferroelectric ceramics are widely used as new smart materials due to their strong coupling between electric and mechanical fields. Our aim is to present a macroscopic constitutive model for ferroelectric ceramics based on Two-Surface theory of Plasticity, According to the microscopic evolvements of domains in ferroelecrics under electric and mechanical loadings, a switching surface of material is introduced, and a saturated surface of material is proposed firstly. The general distance between the switching surface and the saturated surface is regarded as the internal variable, which expresses the non-linear behavior of ferroelectric ceramics. The predicted hysteresis and butterfly loops by this model are in good agreement with the form of loops observed experimentally.