用于铁路线路基础结构伤损识别的概率密度分布演化方法

Probability Density Distribution Evolution Method for Damage Detection of Railway Infrastructure

基于随机分析理论,考虑线路不平顺及系统动力参数的时-空随机演变特性,将车辆-轨道耦合动力学理论与概率密度演化方法结合,提出一种用于线路基础结构伤损识别的概率密度分布演化方法。方法的核心思想是车-线系统在不同不平顺激励源和系统参数联合随机域下的振动响应概率密度分布形态是基本确定的,一旦确定随机域下的振动响应概率密度分布发生较大变化,可判断车-线系统处于非正常状态。采用构建的理论分析模型,准确识别了轨下胶垫垂横向动力系数在不同伤损程度下的衰减情况。

Based on general theory of random analysis,and considering the temporal-spatial stochastic evolution characteristics of track irregularities and dynamic parameters,this paper combined vehicle-track coupling dynamics with probability density evolution method,and proposed a probability density distribution evolution method towards damage detection of railway infrastructure.The core idea of this method is the probability density distribution patterns of vibration responses of vehicle-track coupling system are basically determined under joint random fields of different track irregularity excitation sources and system parameters.Once great changes of the probability density distribution of system responses have occurred,the abnormal conditions of vehicle-track system could be identified.On the basis of the theoretical model,the damages of rail pads under different degree are accurately identified through the attenuation of vertical and lateral dynamic coefficients.