A Zener-Stroh crack in a fiber-reinforced composite material

A Zener-Stroh crack is formed by coalescing a dislocation pileup and theref ore is a net dislocation loaded crack. In this paper, the interaction betwe en a Zener-Stroch crack and surrounding cylindrical fibers in a fiber-reinf orced composite material has been investigated. The crack is located in the matrix and near a fiber, while the influence of other fibers on the crack is considered through the three-phase composite cylinder model. Using the s olution of stress field for a single dislocation in a three-phase cylinder as the Green's function, the crack is represented by a continuous distribut ion of dislocations. A set of singular integral equations are thus formulat ed and solved numerically. The stress intensity factor (SIF) on the crack t ip due to crack-inclusions interaction is calculated. The results show that the volume concentration of fibers has non-negligible influence on the SIF of the crack. (C) 2000 Elsevier Science Ltd. All rights reserved.