变幅加载下疲劳可靠性分析

FATIGUE RELIABILITY ANALYSISUNDER VARIABLE AMPLITUDE

分别对疲劳载荷、寿命与强度的随机性进行了分类。基于二维概率Ｍｉｎｅｒ准则，建立了在变幅载荷谱或随机时间历程载荷谱给定的条件下，对结构构件进行疲劳可靠性分析的新方法，并由此推导出统计Ｍｉｎｅｒ准则中α的分布。最后，分别给出了实验数据验证结果和工程应用实例，显示出该方法具有简便性和实用性。

First of all,randomness of fatigue loading,fatigue life and fatigue strength are classified into three types of random-constant amplitude,random-variable amplitude and random-stochastic time history,respectively.Then,according to Miner's two-dimensional Probabilistic Rule,a new reliability-based prediction procedure of fatigue life is established for the structural component subjected to one-dimensional and two-dimensional cyclic loadings of variable amplitude or stochastic time history.Meanwhile,the probability distribution of α in Statistical Miner Rule is derived.The verification of the obtained results by means of variable amplitude experiment at data of fatigue life shows that the new prediction procedure is very accurate.In the end,an example is presented in detail,which indicates that this new procedure is of simplicity and of feasibility in engineering application.