A Novel Strength Model with Increased Flexibility for Predicting Failure of Unidirectional Fiber-Reinforced Composites

摘要

Strength models for composites are vital for understanding their behavior andrnpredicting their properties. A novel and flexible strength model is devised forrnunidirectional fiber-reinforced composites. This model proves the importance ofrnmatrix cracks around broken fibers for adequate strength predictions. These matrixrncracks increase the stress concentrations in the intact fibers as well as the stressrnrecovery zone in broken ones. An enhanced superposition principle is devised forrnpredicting the stress redistribution around multiple fiber breaks, based on solutions forrna single fiber break. This approach is validated for matrix cracks around broken fibers.rnFinally, the failure development without and with matrix cracks is compared. Matrixrncracks reduce the predicted failure strain of a carbon fiber composite by 0.4%. Thisrnreduction is explained based on the development of break clusters, which occur morernrapidly in models with matrix cracks.