中文摘要：

为了能够以少量的疲劳实验数据推定均值S-N曲线同时更好地评估材料疲劳极限，提出了使用小样本数据评估疲劳极限的方法．基于JSME建议的小样本疲劳实验方法获得14个应力-寿命数据；假设在不同的寿命下疲劳强度的分布与寿命无关且近似相同．基于线性累积损伤原理，将S-N曲线中折断点的应力数据等效换算为一组应力，根据换算后的应力值确定均值S-N曲线的最佳转折点寿命札后获得了均值S-N曲线和疲劳极限的分布．疲劳极限的评估结果表明，所提方法的评估结果与JSME建议的方法相比具有更高的置信度，因此该方法能更好地对小样本数据下的疲劳极限进行评估．

英文摘要：

In order to evaluate the mean S-N curves and fatigue limits of materials, an evaluation method based on small data samples was proposed. Limited data of stress vs. life was obtained from 14 specimens, using measurement methods proposed by the Japanese Society of Mechanical Engineers （JSME）. The new method proposed by the authors uses the linear theory of cumulative damage and assumes that the distribution of fatigue strength is irrelevant to fatigue life, and approximately identical at different numbers of cycles. The data at the breakoff point from the S-N curves were transformed into one set of stress. The optimal value of No, at the turning point of the inclined line and the horizontal line was decided according to the converted stress. The mean S-N curve and the distribution of fatigue limits could then be obtained. The results of fatigue limit evaluation using the method proposed in this paper had higher confidence levels than those based on the JSME method. The proposed method for small sample data sets improved evaluations of fatigue limits.