中文摘要：

基于动力学仿真模型,将轨道不平顺作用下的车辆系统动力响应指标分为整修、恶化、保养3个区域,计算、统计学习轨道不平顺指标与车辆系统部件动力响应指标域之间的关联关系,建立并获得车辆系统动力响应指标域估计模型及不同动力响应指标的域界线.根据单一变量法原理,将车辆-轨道系统激励源划分为轨道不平顺及其它综合因素（如温度荷载、材料损伤等）,依据动力响应指标域估计模型提出了一个简单的线路基础状态反演方法.其基本原理为：若轨道不平顺统计特性不变而其它影响因素变化时,动力响应指标的估计域与实测域将会产生等级跃变,由此判定线路基础状态是否正常.仿真计算结果表明：车辆系统动力响应指标的域估算准确率在80%以上;针对扣件脱空这一线路基础结构损伤工况,识别准确率在70%以上.

英文摘要：

Based on the dynamic simulation model,this paper divided the dynamic response indexes of the vehi-cle system under the track irregularity into three regions,namely rebuilding region,deteriorating region and maintaining region,built the region estimation model of dynamic response indexes,and acquired the boundary lines of different regions with the valid mapping relation between track irregularity indexes and the dynamic re-sponse regions of vehicle system components.On the basis of above model and simple variable method,the au-thors further divided the excitation sources of vehicle-track system into track irregularity and other composite factors （such as temperature load,material damage,etc.）and put forward a relatively simple dynamic inver-sion method for railway line infrastructure status,according to the region estimation model of dynamic re-sponse indexes.The basic principle of the method is that if statistical properties of the track irregularities re-main unchanged,while other composite factors change,the estimation and the actual measured regions of the dynamic response indexes will produce a step change,whereby the elemental status of the railway can be deter-mined as normal or not.The simulation results showed that the accuracy rate of region estimation for the dy-namic response indexes was above 80%,while the identification accuracy for line structural damage condition of fastener disengaging was above 70%.