Debonding criterion for the piezoelectric fibre push-out test

A theoretical model of piezoelectric fibre push-out is developed within the framework of a modified shear-lag theory to study stress and electrical field transfer. Based on the model, a debonding criterion for the piezoelectric effect is presented utilizing a fracture-mechanics approach to investigate the debonding process of piezoelectric fibre in the push-out test for combined electrical and mechanical loading, and for mechanical loading only. A numerical example is considered to verify the proposed debonding criterion. The results show that stress and electrical fields can be controlled by the interface. The study also shows that interfacial properties and piezoelectric coefficients have a significant influence on the debonding process of piezoelectric fibre composites, and the energy-release rate can be enhanced or reduced depending on the direction of electrical loading, which shows that the energy-release rate can be used as the debonding criterion.