Multiaxial models and experiments with ferroelectrics

The use of ferroelectrics in increasingly demanding roles as sensors and actuators motivates study of their fundamental constitutive behaviour. This paper gives a preliminary report on measurements of the behaviour of PZT-5H under multiaxial loading paths, and comparison with model predictions. The loading paths considered are loading of poled material with electric field at various angles theta to the poling direction, and loading with uniaxial compressive stress rotated through various angles theta to the poling direction. In each case the material response is measured by tracking electric displacement in the form of surface charge. Model predictions are made using a self-consistent crystal plasticity approach. The model is able to predict well the response to multiaxial electric field loading. There is good qualitative agreement in the case of mechanical loading.