Prediction of the strength of notched fiber-dominated composite laminates

Abstract An investigation has been conducted to predict the tensile and compressive strengths of fiber-dominated composite laminates with notches. Research shows that the strength of a notched fiber-dominated laminate can be evaluated from the failure prediction for the 0° plies in the laminate. On the basis of this study and the frequently used ‘characteristic length’ concept, a lay-up-independent failure criterion, the load-bearing ply-failure criterion (LBPF), is proposed, which relates the laminate strength to the failure of the principle load-bearing ply. Two characteristic lengths are obtained for tension and compression, respectively. Results indicate that, in most cases, the two characteristic lengths are properties of a composite material system, regardless of laminate configurations. Once these two parameters are estimated from preliminary tests on notched multidirectional laminates of the material, they can be used to predict the notched strength of fiber-dominated laminates of the same material. Good consistency is observed between test results and predictions.