A Normal Crack in a Piezoelectric Actuator with Functionally Graded Properties under a Transient Thermal Load Combined with an Electric Load

Abstract

In this paper, the fracture problem of a piezoelectric actuator consisting of a functionally graded piezoelectric material strip (FGPM strip) and a homogeneous layer by a transient thermal load combined with an electric load is considered. The FGPM strip contains a crack perpendicular to the interface. Material properties of the FGPM strip are assumed to be exponentially dependent on the distance from the interface. The thermo-electro-mechanical fields in the un-cracked laminate induced by the transient thermal load and the electric load are calculated. By using the superposition technique, the obtained normal stresses are used as the crack surface tractions with opposite sign to formulate the mixed boundary value problem. The integral transform techniques are employed to reduce the problem to the solution of a singular integral equation. The stress intensity factors are computed, and the results are presented for the various values of the nonhomogeneous and geometric parameters. We also focused on the crack contact phenomenon for the case of the pure electric load. Moreover, the effect of the difference between two kinds of the electric boundary conditions on the stress intensity factors under transient thermal load and the reduction of ones by the electric load would be discussed.