| The newly developed functionally graded materials (FGMs) may have wide technological applications. These materials are designed in a way that combines beneficial mechanical and strength properties of different materials to create some new materials useful in practice. The composition and hence the properties of FGMs vary spatially, which make them suitable for specific requirements encountered in engineering applications.; Some crack problems in FGMs have been solved during the past decade, but most of these studies are limited to semi-infinite or infinite domains and symmetric problems. In this thesis, the more general problem of an arbitrarily oriented crack in a FGM layer is investigated. Specifically the stress intensity factors and crack opening displacements for a functionally graded layer bonded to a substrate are studied analytically. Variable mechanical loads are applied to make it more general.; The problem will be formulated in terms of a system of singular integral equations, which can be solved numerically. The stress intensity factors at the crack tips are computed. A complete parametric study, by varying both the geometric and material parameters, is conducted. When possible, results are compared to existing experimental data and other numerical results.; It is believed that the information obtained through this study will provide a solid foundation for further theoretical studies using the singular integral equation approach to fracture problems in advanced composites. |
