Analysis of an Axisymmetric Matrix Crack with Interfacial Debond

Interfacial debonding might occur with an increasing tensile load in a unidirectional fiber-reinforced composite. This debonding is assumed to be a significant contributor to increased composite toughness. A model is developed to analyze the stresses and energy release associated with a unidirectional composite containing matrix crack with interfacial debonding. A consistent shear-lag model in cylindrical coordinates is developed and the friction effect at the fiber/matrix interface is modeled by applying constant interfacial stresses in the debonded region. The governing equations are solved using an eigenvalue technique. The debond stresses are compared with the results of the single fiber pull-out experiment. A parametric study is performed for different constant values of interfacial stresses in the debond region, fiber embedded lengths and fiber diameters. A criterion for either the crack penetration or the debond growth is discussed.