两种国产涡轮盘材料疲劳寿命概率分布规律初探

基于两种国产发动机轮盘材料GH4133和1Cr11Ni2W2MoV低循环疲劳实验数据,选择三种常用的分布函数(对数正态分布、双参数Weibull分布和三参数Weibull分布),用概率图法和柯尔莫哥洛夫-斯米尔诺夫检验方法进行拟合优度检验,以考察分布函数的总体拟合效果.通过经验失效率的变化趋势来评估分布函数是否符合疲劳失效机制.结果表明:形状参数大于1的三参数Weibull分布函数是建立国产轮盘材料GH4133和1Cr11Ni2W2MoV疲劳寿命分布的理想数学模型.对数正态分布函数在本工作所研究的轮盘材料低循环疲劳寿命范围内是合理的.双参数Weibull分布函数用作国产轮盘材料疲劳寿命分布模型时必须进行假设检验.

Preliminary Investigation of Fatigue Life Probability Distribution for Two Domestic Turbine Disc Materials

The goodness-of-fit tests were carried out to check the overall fitting effect on distribution function on diseribution function.According to the fatigue initiation life test data taken from domestic aero-engine disc materials GH4133 and 1Cr11Ni2W2MoV,choosing three commonly used distribution types(lognormal distribution,two-parameter Weibull distribution and three-parameter Weibull distribution),using probability charts and the Kolmogorov-Smirnov test.The empirical failure rates at different lives were calculated to evaluate consistency to fatigue failure mechanism.The results show that the three-parameter Weibull distribution whose shape parameter is greater than 1 is the better mathematical model of fatigue life distribution for domestic disc materials GH4133 and 1Cr11Ni2W2MoV in a wide range.Lognormal distribution is reasonable in the low cycle fatigue life range of disc materials studied.The two-parameter Weibull distribution used to be fatigue life distribution for domestic disc materials is preceded by hypothesis test.