Interface Crack Problems for FGM Coating

This book presents an analytical benchmark solution for the interface crack problem. It is assumed that the composite medium consisting of a substrate, a bond coat and a graded top coat is under plane strain conditions, contains an interface crack between the top coat and bond coat, and is subjected to arbitrary general loading conditions. The main results of this study are the mode I and II stress intensity factors and crack opening displacements. Also, temperature distribution and thermal stresses in homogeneous material containing an insulated barrier subject to constant heat flux are examined. Using Fourier transforms for displacements in the plane strain crack problem, the mixed boundary conditions are analytically reduced to a system of dual integral equations and then, by a systematic approach, to a system of singular integral equations. After converting the system of singular integral equations to a system of functional equations, such physically important quantities as stress intensity factors and crack opening displacements are obtained numerically by using certain approximate techniques.