Fatigue life prediction of CFRP composite laminates under repeated flexural loading

摘要

In order to evaluate the degradation in stiffness for determining a damage function, flexural fatigue tests with different stress levels are first conducted on the carbon fiber reinforced plastics (CFRP) cross-ply laminates. Then, based on the damage function, a cumulative fatigue damage rule for predicting the lifetime for the composites subjected to a multi-stress level fatigue loading is proposed. Finally, the two-stress level fatigue tests are performed to verify the proposed rule. From the present study, the damage function is found to increase cubically with an increasing number of cycles for each stress level and it is also found that the lifetime obtained from the two-stress level fatigue tests is longer than the predicted one for the stress increasing case, while it is shorter for the stress decreasing case.