Thermal Residual Stress and Interphase Effects on Crack-Inclusion Interactions

An analytical investigation is conducted into the problemof a matrix crack interacting with an inclusion possessing an interphase and subjected to a thermal load. The interphase is modeled as a third, homogeneous phase surrounding the circular inclusion. By using a dislocation based approach to model the crack, along with an analytical solution to the thermal stress problem, a set of singular integral equations are formulated and then solved using established numerical techniques. The solution is applied to a glass fiber–epoxy composite system having either radial or circumferential matrix cracks and undergoing a uniform temperature change. This solution gives a quantitative and analytical method to evaluate the influence of interphase properties on the stress intensity factors of nearby, thermally loaded microcracks.