Turkish Journal of Engineering and Environmental Sciences

Abstract: The basic interface crack problem in a nonhomogeneous coating with continuously varying elastic properties bonded to a homogeneous semi-infinite medium is examined. The problem is encountered in studying the fracture mechanics of functionally graded materials, which are mostly 2-phase particulate composites with continuously varying volume fractions. The objective of this study is to determine the effect of the material nonhomogeneity parameters and relative dimensions on the stress intensity factors (SIFs). With the application to fracture mechanics in mind, the main result given in this study is the SIFs and crack opening displacements (CODs) as a function of the nonhomogeneity and the length parameters for various loading conditions. Using integral transforms for the displacements in the plane strain crack problem, the mixed boundary conditions are analytically reduced to a system of singular integral equations that are solved numerically using certain approximate techniques.

Key Words: FGMs, Mixed-mode loading, Singular integral equations, Stress intensity factors, Crack opening displacements.