Stress and fracture analysis for systems with inhomogeneities.

Abstract

The inhomogeneities situated in materials render the diversification of composite families, and can provide synergistic effects for tailoring materials to a specified and often hostile environment. The work presented here focuses on the fracture and stress analysis of systems with various inhomogeneities. In Chapter 1, interactions among cracks and rigid-line inclusions are investigated. Rigid-line inclusions are represented by a distribution of forces while cracks are modeled by the standard dislocation approach. Chapter 2 presents an analysis of composite systems with interacting cracks and a dilute distribution of inclusions. A damage analysis procedure is developed to evaluate the effective properties of such composites. Chapter 3 examines multiple void-crack interactions. The formulation is based on a mixture of dislocations and tractions. Chapter 4 presents an approach to modeling bridged crack systems. A fully regular integral equation formulation is developed and the approach is ideally suited for the analysis of systems with large number of closely spaced inhomogeneities. The integral equations of different forms, developed throughout the dissertation can also be utilized to evaluate and verify various micromechanical models. The possible future extensions and the major limitations of the present work are briefly discussed in Chapter 5.