摘要
以独立多细节结构概率失效模型为基础,进行Monte Carlo抽样,检验独立多细节结构的寿命分布特性,结果表明:可近似认为独立多细节结构疲劳寿命分布形式与单细节相同,但分布函数首尾两端精度较低。若单细节疲劳寿命服从对数正态分布,当细节为相同细节,独立多细节结构疲劳寿命的数学期望和方差均低于细节数学期望和方差,并与细节寿命分布参数存在明确关系;当细节为不同细节,独立多细节结构疲劳寿命的数学期望和方差均低于细节寿命的最大数学期望和最大方差;当单细节服从双参数Weibull分布时,若细节为相同细节,独立多细节结构疲劳寿命分布的斜率参数不变,尺寸参数按比例缩小。若细节为不同细节,独立多细节结构疲劳寿命分布的形状参数大于最小形状参数,位置参数小于最大位置参数。最后对独立多细节结构疲劳寿命分散系数表达式进行了分析。
On the basis of a series of failure models,the Monte Carlo sampled method is used to test the fatigue life distribution of a multi-detail（MD）structure.The simulated result shows the fatigue life of a MD structure follows the same distribution as the single detail（SD）structure,but unprecise in the tail.The distribution parameters of the MD structure are deduced when the fatigue life of SD follows the log-normal distribution.The MD’s expectation and variation are lower than the SD’s if the details are the same and lower than the maximal value of the SD if the details are different.Assuming the fatigue life of the SD follows the two parameter Weibull distribution,the MD has the lower scale parameter and the same slope,the different MD’s scale parameter is lower than the maximal scale parameter,and the slope is larger than the minimum slope.Finally,the fatigue scatter factor of a MD structure is discussed.
出处
《工程力学》
EI
CSCD
北大核心
2010年第8期217-222,共6页
Engineering Mechanics
