采用同分布概率演化法求解脱轨系数的概率分布  

Probability Distribution of Derailment Factor Using Identical Probability Distribution Evolution Method

作　　者：周子骥 张楠[1] ZHOU Ziji;ZHANG Nan(School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]北京交通大学土木建筑工程学院,北京100044

出　　处：《铁道学报》2023年第12期131-137,共7页Journal of the China Railway Society

基　　金：国家自然科学基金(52178101)。

摘　　要：为更好地了解高速列车脱轨系数的随机性,采用同分布概率演化方法研究脱轨系数的概率分布函数及其高斯特性的统计证明。通过横、竖向轮轨力的均值与标准差验证脱轨系数近似服从高斯正态分布,并提出脱轨系数的近似分布函数(柯西似分布),为脱轨系数的概率统计以及阈值研究提供参考。采用蒙特卡洛法验证了脱轨系数近似服从正态分布,其柯西似分布函数能较好地拟合脱轨系数样本。然后,以6节车先锋动车组列车通过3跨32 m简支桥梁为例,讨论不同列车速度、不同轨道不平顺谱和不同桥梁挠跨比工况下,脱轨系数的高斯特性与柯西似分布函数的适用性。最后,利用现场试验数据验证本文理论方法的准确性。结果表明,高速列车脱轨系数高度服从正态分布,柯西似分布可用于脱轨系数的统计研究。To better understand the randomness of the derailment factor of high-speed trains,its probability distribution functions(PDFs)and statistical proof of its Gaussianity were studied using the identical probability distribution evolution method(IPDEM).The derailment factor was shown to approximately obey a Gaussian normal distribution determined by the mean and standard deviation of the lateral and vertical wheel-rail forces,and an approximate distribution function(approximate Cauchy distribution)of derailment factor was proposed to provide reference for the probability statistics and threshold research of the derailment factor.The Monte Carlo method(MCM)was used to determine whether the derailment factor approximately obeys the normal distribution,and approximate Cauchy distribution can well fit the derailment factor samples.Based on the case study of a 6-car Pioneer EMU train passing through a 3-span 32 m long simply supported bridge,discussions were made on the Gaussian characteristics and the applicability of the approximate Cauchy distribution function of the derailment factor under varying train speeds,different track irregularities,and different bridge deflection/span ratios.Finally,experimental data obtained from a field test were used to verify the accuracy of the theoretical approaches.The results confirm that the derailment factor of high-speed trains approximately follows the normal distribution,and the approximate Cauchy distribution can be used in statistical studies of the derailment factor.

关 键 词：高速铁路 脱轨系数 同分布概率演化法 正态分布 柯西似分布 

分 类 号：U441.3[建筑科学—桥梁与隧道工程] U24[交通运输工程—道路与铁道工程]