カーボン短繊維強化ナイロン複合材料の異なる応力比に対する PSN 曲線の予測

抄録

The statistical distributions of fatigue lives of stampable CF/PA composite at different stress ratios are identified, and a procedure for predicting the S-N relationships for any stress ratios that consider the influence of the probability of failure P is proposed. Constant amplitude fatigue tests are performed at different stress ratios R=0.1, 10 χ (≡ σUCS/σUTS), respectively. To identify the statistical nature of fatigue life data, a lognormal distribution and a Weibull distribution are applied to the fatigue data obtained, respectively. The anisomorphic constant fatigue life (CFL) diagrams for different probabilities of failure (10%, 50% and 90%) are constructed on the basis of the P-S-N curves for the critical stress ratio. It is shown that the P-S-N curves for different stress ratios can successfully be predicted using the methodology proposed in this study.