Micromechanics of Failure in Composites

Abstract

An analysis of fracture resistance mechanisms in several composite systems is presented. A description of the basics of the analytical method developed specifically for the analysis of fracture development in composites is presented as a unified approach to different composite systems. The method was applied to several composite systems, including composites formed from a brittle matrix reinforced by unidirectional fibers, composites consisting of a brittle matrix reinforced by ductile particles, and a metal matrix reinforced by ceramic fibers. The reinforcement mechanisms in these composites are based on the formation of a system of restrictive forces imposed on the crack surfaces by reinforcing components. The region where these restrictive forces are activated is represented as a line process zone. A classical fracture mechanics modeling technique was employed, using the process zone concept and small or large-scale analysis. The distinctive characteristic of the described method is an explicit consideration in the analysis of the discrete distribution of the reinforcing components within the composite. The developed methodology allows one to obtain analytical solutions to the representative elasticity problems and to investigate detailed micromechanical aspects of the process.