A New Approach to Fatigue Damage Modeling of Composite Laminates

Abstract

Fatigue damage of composites can be described by the residual stiffness and residual strength, and the same damage state can be described by the two mechanical parameters equivalently. Based on this assumption, a new pair of fatigue damage accumulation models are established to simulate fatigue behavior and predict the fatigue life of composites. Each of two equations contains three parameters and has the similar form, and the power function relationships between the two damage indices are constructed. The proposed model, combining with constant life diagrams and failure criteria are used to estimate the fatigue life of composites, and good agreement is observed between the present model and experimental results.

A model of strength degradation for glass fiber reinforced polymer composite laminates under fatigue loading

“…31,32 Therefore, in this paper, a semi-empirical fatigue damage accumulation model is used, which can describe three stages of fatigue damage evolution process in GFRP. In other words, the model is able to simulate the rapid damage growth stage of the initial cyclic loading, the slow growth stage when the characteristic damage state is reached, and the rapid damage expansion stage before rupture, as shown in equation (1) 33 where DE is the fatigue damage function, N is the fatigue life, n is the number of loading cycles, and a b and c are three fitting parameters of GFRP test data and can be determined using the least square method.…”