Fatigue life prediction in composites

Because of the relatively large number of possible failure mechanisms in fibre reinforced composite materials, the prediction of fatigue life in a component is not a simple process. Several mathematical nd statistical models have been proposed, but the experimental evidence to support hem is limited so far. In this paper, an attempt has been made to fit experimental results to two of the more promising models. Results obtained from repeated tension fatigue tests on unidirectional carbon fibre reinforced epoxy were used to test residual strength and residual stiffness models. Further fatigue tests were carried out under spectrum loading so that the results could be correlated with the cumulative damage predicted by the residual strength model