摘要基于疲劳强度随加载循环次数增加不断劣化的物理事实，采用Euler描述推导出疲劳强度与随机参数联合概率密度函数满足的演化方程。采用数值求解方法，给出疲劳强度-寿命概率密度曲面（probability density S-N），并可据此计算给定存活率的p-S-N曲线。基于疲劳试验结果的算例分析表明，疲劳强度-寿命概率密度曲面、Monte Carlo模拟及具有给定分位数参数的S-N关系三者计算的p-S-N曲线吻合良好。疲劳强度-寿命概率密度演化方法可不依赖分布假定给出S-N关系的完备概率描述。
Abstract：Taking the degradation of fatigue strength with increasing of loading cycles into account, the joint probability density evolution equation of fatigue strength and random factors is derived in Euler description. Probability density S-N (pd-S-N) surface is predicted by a numerical method, which is able to calculate the p-S-N curve with given survivability. The analysis based on experimental fatigue data indicates that p-S-N curves for both mean and 95% survivability predicted by pd-S-N, Monte Carlo and parameters with given fractile show good agreements. pd-S-N provides complete probability information of S-N relationship independent of the probability distribution assumption.
2013, Vol. 32 
