Contact problem of functionally graded piezoelectric interface layer under a spherical punch postprint

Abstract:
The discontinuous variation of material properties is an important reason for the crack initiation and delamination at the interface.Therefore,using functionally graded piezoelectric materials with continuous variation of material properties as the interfacial layer is an important method to affect the crack initiation and delamination at the interface.In this paper,the axisymmetric frictionless contact problem of piezoelectric coating-functionally graded piezoelectric interfacial layer-piezoelectric substrate structure under a rigid insulating spherical punch is studied.First,assuming that the coating and substrate are homogeneous piezoelectric materials,the contact mechanics analysis model of functionally graded piezoelectric interfacial layer with material properties varying in the form of exponential function along the thickness direction is established.Then,the axisymmetric frictionless contact problem of piezoelectric coating-functionally graded piezoelectric interfacial layer-piezoelectric substrate structure under a rigid spherical punch is transformed into a singular integral equation by using Hankel integral transformation method and solved by numerical integration method.Finally,the effects of material inhomogeneous properties on the electromechanical responses of coating,gradient piezoelectric interfacial layer,substrate structure and interface are obtained.The results show that when the functionally graded piezoelectric materials can be used as the interfacial layer to connect the piezoelectric coating and substrate,the interface stress discontinuity caused by the discontinuity of material properties at the interface can be eliminated.The variation of gradient piezoelectric material properties in the interfacial layer has a significant effect on the stress and electric displacement components of the interface layer.