An energy based failure criterion for matrix crack induced delamination in laminated composite structures

Available failure criteria for the design of laminated composite structures do not explicitly take into account the occurrence of delaminations induced by matrix cracks. However, depending on the material properties, laminate stacking sequence and ply thickness, this failure mode may appear and compromise the structural integrity of the structure. In this work, a failure criterion for predicting matrix cracking induced delamination in laminated composites is presented. The failure criterion is developed within the framework of Fracture Mechanics, by comparing the energy release rate available for delamination extension near a matrix crack and the fracture toughness of the interface. The predicted failure loads agree well with experimental data available in the literature, thus supporting the introduction of this failure criterion into the set of failure criteria usually considered in composite’s structural design.