A Phenomenological Constitutive Model of Ferroelectrics with Gradual Domain Switching

In this paper, a phenomenological, nonlinear constitutive relation of ferroelectric ceramics is established by considering the fact that domain switching happens gradually with the external loading. A simplified gradual switching model is suggested and implemented into the constitutive law of ferroelectric materials. The volume fraction of domain switching is used as the internal variable in the model, and its evolution equation with mechanical/electrical loading is given. Comparison with experimental results shows that this simple constitutive model can predict the nonlinear hysteresis responses of ferroelectric materials.