Transient behavior of an orthotropic layer with imperfect FGM coating containing multiple interfacial and embedded cracks under anti-plane shear impact load

Abstract

This paper investigates the transient response of an orthotropic strip with functionally graded (FG) coating weakened by multiple embedded and interfacial cracks. The first part of this paper is concerned with the dynamic response of embedded cracks in the orthotropic substrate with imperfect FG coating. In the second part, the solution of interfacial crack is obtained analytically to extract the dynamic stress intensity factors (DSIFs). In the third part, the proposed method is developed to examine the dynamic fracture behavior of coating–substrate system with an orthotropic FGM coating bonded to an orthotropic substrate through a layer of a bond-coat. In all parts, Laplace and Fourier transforms are used to reduce the problems to a set of singular integral equations with Cauchy kernels which are solved numerically in the Laplace transform domain. The dynamic stress intensity factors are obtained by the numerical Laplace inversion technique. Several examples are solved to obtain DSIFs with various crack lengths and the spring constant of imperfect bonding and material properties of the layers.