FATIGUE RELIABILITY-ANALYSIS OF COMPOSITE LAMINATES UNDER SPECTRUM STRESS

Fatigue reliability of graphite/epoxy composite laminates under uniaxi al spectrum stress is studied using the modified beta-method. A number of cumulative damage models are adopted to construct the limit state equation for the laminates in the reliabilty analysis. Statistics of f atigue life distributions of the laminates under cyclic stresses of co nstant amplitudes obtained from tests are used for the reliability ass essment of the laminates under spectrum stress. The accuracy of the mo dified beta-method in fatigue reliability prediction is then verified by experimental multi-stress level fatigue life data. The applicabilit ies of the modified beta-method and the cumulative damage models in fa tigue reliability prediction are discussed. It has been found that sev eral of the adopted cumulative damage models may be applicable for fat igue reliability analysis of composite laminates under spectrum stress . (C) 1997 Elsevier Science Ltd.