Modeling fracture of resin matrix composites

Abstract Characteristics of the fracture of resin matrix fibrous composites are discussed with emphasis on the physical parameters influencing fracture and the requirements of a suitable model for predicting crack growth. The influences of notch geometry, fiber orientation, specimen geometry, and far field loading on crack growth in unidirectional resin matrix composites are discussed. The normal stress ratio theory is reviewed and its applicability for crack initiation in unidirectional resin matrix composites is considered. Experimental results from a variety of tests on resin matrix composites are reviewed and compared with theoretical predictions. It is shown that the normal stress ratio theory correctly predicts the initiation site and direction of crack growth from an existing notch. Predictions of critical stress are less consistent being quite accurate in some cases, but less accurate in others.