基于线路实测数据统计推断的应力谱分布类型比较

在分析研究轨道车辆结构实测动应力谱分布的基础上,提出用威布尔分布和对数正态分布的组合分布来描述动应力分布.利用实测数据分别拟合出威布尔、对数正态、组合分布三个分布函数,利用拟合结果及实测应力谱进行应力谱统计推断,得到各自的推断应力谱并与实测谱比较,证明了组合分布对实测应力谱分布描述的优越性.同时利用各分布函数估计得到实测中未出现的可能最大值,然后扩展出包含可能最大值的扩展应力谱,在损伤累计理论的基础上,证明了威布尔分布对分布估计的保守性,以及组合分布对应力谱分布估计的有效性.

Comparison of the Distribution Type for Stress Spectrum Based on Statistical Inference of Line Measured Data

Raised combined distribution of weibull distribution and lognormal distribution to describe the dynamic stress distribution on the base of studying and analysis of distribution for measured dynamic stress of rail vehicle structure.Fitted three distribution functions of weibull,lognormal,and combined distribution with measured data,and get statistical inference stress spectrum with the result and measured stress spectrum.Compare the new stress spectrum with the measured spectrum,to prove that the combined distribution is better to describe the measured data.Then estimate the maximum value which may not be measured in the test,with function of different distributions,and then calculated spread stress spectrum which may contain the maximum of stress in the test.Proved the conservative of the weibull distribution to estimation of distribution,and the effective of the combined distribution to effimation of stress spectrum distribution.