相似多细节结构疲劳试验不完全数据参数估计

讨论了用含相似多细节结构的不完全疲劳试验数据进行疲劳特征参量分布参数估计的方法.在假设疲劳寿命服从对数正态分布和双参数Weibull分布的情况下,分析了用于描述单个细节疲劳质量的随机变量的分布参数与含相似多细节结构不完全试验数据的分布参数之间的关系,分析表明二者之间存在显著的差异,但具有确定性的关系,这种关系与细节个数有关,给出了通过不完全试验数据估算单个细节疲劳分布参数的定量方法.通过数值模拟,分析了样本容量和细节个数对估算结果分散性的影响,分析表明,在细节数较少时,对分散性的影响与样本容量有关,与细节个数关系不大.

Estimation method for inadequate fatigue test result of structures with multi-similar-details

A method for estimating fatigue life distribution parameters with inadequate result obtained by fatigue test of structures with multisimilar-details was proposed.Based on the assumption that fatigue life follows the log-normal distribution and 2-parameter Weibull distribution respectively,the relationship of two kinds of distribution parameters,one was adopted to describe the single detail fatigue quality and the other was gained by inadequate test results of multi-similar-detail structures,was discussed.The analysis indicates that there is a significantly difference between the two kinds of parameters,however a determinate function of the amount of details can be obtained to describe this relationship.The way of estimating single detail fatigue distribution parameters via inadequate data was presented.Numerical simulations were conducted to analysis the effects of number of specimens and the amount of details on the estimating results,which shows that when the amount of details is not very large,it is the number of specimens,but not the amount of details,which has great effect on the dispersivity of parameter estimation.