Dynamic mode-III interfacial crack in ferroelectric materials

Abstract

This work is concerned with the analytical characterization of the electromechanical nonlinear effects on the fields surrounding the tip of an interface crack of Yoffe type between ferroelectric-plastic bimaterials. A strip electric saturation and mechanical yielding model is developed for a mode III dynamic interfacial crack with electrical polarization reaching a saturation limit and shear stress reaching a yield stress along a line segment in front of the crack. The electrical saturation zone and mechanical yielding zone may have different length scales depending on loading conditions. The results reveal insight into the structure of stress and electric displacement fields for different load conditions. The energy release rate and COD(crack-tip opening displacement) are also be obtained. It is also shown that the smaller nonlinear zone (mechanical yielding or electric saturation) size is related with the velocity v of the interfacial Yoffe crack. COD, COP (crack-tip opening potential) and the energy release rate J_a(v) all increase monotonically with increasing v .