Stiffness Degradation Model for Fatigue Life Prediction of GFRPs Under Random Ocean Current Loading

摘要

A new phenomenological fatigue model based on stiffness degradation isproposed for life prediction of Glass Fiber Reinforced Plastics (GFRPs) under randomocean current loading. The model used Weibull cumulative density function toaccount for a shift in failure modes and corresponding change in the rate of damageaccumulation. The effects of stress ratio and stress amplitude on the model parameterswere characterized using the results from constant amplitude tests. The fatigue life ofGFRP coupons under random ocean current loadings was predicted both by theproposed model and by the conventional life prediction methodologies usingPalmgren-Miner’s rule. The fatigue life was predicted within a factor of two by theproposed model, which was more accurate than the conventional methods.