论文部分内容阅读
在进行疲劳试验评定结构寿命时,为了能真实模拟实际结构形式和传载情况,模拟试件往往设计成多细节试件,进行不完全疲劳寿命试验,必须由多细节试件寿命推断单细节寿命.针对工程上常用的两种寿命分布形式:对数正态分布和双参数Weibull分布,以结构串联失效模型为基础,建立了由相同独立多细节结构疲劳寿命分布确定单细节寿命分布的统计标定方法.当多细节试件寿命服从对数正态分布时,可近似认为单细节寿命也服从对数正态分布,单细节寿命分布参数与多细节试件寿命分布参数间存在确定关系,并且单细节寿命数学期望和标准差均高于多细节试件相应参数;当多细节寿命服从双参数Weibull分布时,单细节寿命也服从双参数Weibull分布,其斜率不变,但位置参数按比例放大.最后给出了一个分析实例.
When fatigue test is used to evaluate the structure life, in order to simulate the actual structure and load situation, the simulation specimen is often designed as a multi-detail specimen for incomplete fatigue life test, which must be deduced from the life of multi-details specimen. Aiming at the two kinds of life distributions commonly used in engineering, such as lognormal distribution and two - parameter Weibull distribution, the statistical calibration to determine the single - minded lifetime distribution from the fatigue life distribution of the same independent multi - detail structure is established based on the structural series failure model Method.When the life of multi-detail specimen obeys the log-normal distribution, the life expectancy of single detail can be approximated to be logarithmic normal distribution, and there is a certain relationship between the parameters of life distribution of single detail and life parameters of multi-detail specimen, The expected life expectancy and the standard deviation of detail life are both higher than the corresponding parameters of multi-detail specimen. When the multi-detail life obeys the double-parameter Weibull distribution, the single-life also obeys the two-parameter Weibull distribution with constant slope but the position parameter is scaled up. Finally, an analysis example is given.