Propagation of a mode-III interfacial conductive crack along a conductive interface between two piezoelectric materials

For the mode-III crack propagation in piezoelectric materials, an electro-acoustic surface wave, the Bleustein-Gulyaev wave, controls the crack propagation speed. It is shown that the propagation of an interfacial crack in piezoelectric media may excite an interfacial electro-acoustic surface wave, the Maerfeld-Tournois wave, which is fundamentally different from the mode-III interfacial crack propagation in purely elastic media. Moreover, it has been discovered that the existence of the Maerfeld-Tournois wave may play a significant role in determining the dynamic fracture toughness for piezoelectric composites.