Fatigue reliability analysis of composites based on residual strength

The fatigue reliability of Gr/PEEK composites has been investigated in the present study. In the experimental investigation, constant amplitude loading, multiple-level loading and random loading have been considered step by step during the fatigue tests. In particular, a residual strength degradation model was presented for predicting the fatigue life of composites subjected to constant amplitude fatigue loading. The accumulation of fatigue damage was determined, using the residual strength degradation model. The residual strength distribution after an arbitrary fatigue cycle can be represented by a two-parameter Weibull distribution function. A fatigue reliability analysis method for arbitrary load history was thus developed through the Weibull distribution function. Good correlation between theory and experiment was obtained for constant amplitude loading, two-level loading, three-level loading and random loading. The result of the present study can be used as a basis for the reliability design of mechanical components made of Gr/PEEK composites.