The purpose of this research is to undertake a combined experimental, computational and analytical study that will provide a fundamental understanding, and quantify the nature of, damage and stress redistribution ahead of the crack tip for creep brittle materials such as ceramics, intermetallics and powder metallurgy alloys, including process zone effects and transient loading conditions. It is also proposed to establish appropriate local/global crack extension criteria for growing creep cracks in creep brittle materials. Unique granular flow solutions for grain boundary sliding associated with boundary diffusion and/or viscosity are expected to shed light on appropriate process zone size scales and driving forces for void growth and coalescence/ These results will be used to construct appropriate crack tip damage models to be used with finite element analysis to better understand the physics which will be evident from the experiments. These advances should have important implications for improving failure predictions of components made of creep brittle materials.
