On the interfacial behavior of a piezoelectric actuator bonded to a homogeneous half plane with an arbitrarily varying graded coating

Abstract In the present paper, the model of a piezoelectric actuator bonded to an inhomogeneous substrate, which is composed of a homogeneous half plane and an arbitrarily varying graded coating, is established. Based on the fundamental solution of the inhomogeneous substrate, the governing integro-differential equation of the model is investigated and numerically solved. The interfacial shear stress and the transverse stress in the actuator are comprehensively analyzed. It is found that the interfacial response of the actuator/substrate system can be modified by tuning inhomogeneity parameter and variation law of the graded coating, material and geometric parameters of the adhesive interlayer, etc. A graded coating abiding by an exponential law corresponds to a more reliable interface and a more durable actuator, compared with a linear one. The results should be very helpful to design various film/substrate structures and choose proper graded coating in real applications.