Statistical analysis on the fatigue strength distribution of T700 carbon fiber

Abstract An experimental method was developed to characterize the fatigue strength distribution of T700 carbon fibers using fiber bundles test. In this method, survival probability, P, of the fiber bundles was first calculated from the stress reductions at different cycles in strain controlled fatigue tests. Based on a fiber bundles model and fatigue P–Strain–N curves, the fatigue strength exponent, b, the Weibull scale parameter σ0 and the Weibull shape parameter β were then determined to characterize the fatigue strength distribution of T700 carbon fiber. A numerical model, based on Monte Carlo simulation, was also established to predict the load-controlled fatigue failure process of fiber bundles. The simulated strain-cycle number curves and stress-cycles curves based on the model developed are in agreement with the test data.