一种随机载荷作用下疲劳可靠性估算的新方法

A New Method for the Prediction of Fatigue Reliability under Random Loading

应用随机过程理论研究了疲劳过程中结构材料的剩余强度退化行为，分析了疲劳过程中两类随机性因素（内在随机涨落和外在随机涨落）在不同载荷条件下对疲劳寿命的影响。在此基础上，提出了一种随机载荷下疲劳可靠性估算新方法。最后，以１５ＭｎＶＮｑ 钢试样的小样本疲劳寿命数据对该方法进行了验证。

A residual strength degradation model is developed based on the random process theory to analyse the effects of two stochastic factors, that is, internally and externally stochastic fluctuations, on fatigue life under various loadings. In the model, a new algorithm to estimate fatigue reliability is presented, which can be used in the cases of given probability distribution of fatigue life under constant loading of materials and given statistics of a random loading history only. The features of this model makes it a practical sense in predicting fatigue reliability during structure design. Finally, a small sampled data of 15MnVNq is used to verify the adaptability of this method.