32.5t轴重货车作用下重载铁路轨道的合理刚度

Reasonable Track Stiffness for Heavy Haul Railway under the Action of Freight Car with 32.5t Axle Load

针对以往轨道刚度计算方法只能得出轨下垫板静刚度的取值范围或下限值,而不能确定轨道整体刚度的问题,运用大型轮轨动力学软件NUCARS建立32.5t轴重货车—轨道系统耦合动力学模型,采用动力敏感系数分析方法,通过分析轨道结构各种部件刚度组合情况下的车辆、轨道系统动力特性,研究32.5t轴重货车作用下重载铁路轨道的合理刚度。结果表明:钢轨垂向位移、道床压力和垫板压力对垫板刚度较为敏感;轨枕垂向位移、轨枕垂向加速度、道床压力对道床刚度较为敏感;以轨道动力特性的综合效应最小为目标建立目标函数,筛选得出32.5t轴重货车作用下重载铁路轨道结构的部件刚度最优匹配方案是轨下垫板刚度为140kN·mm-1,道床刚度为150kN·mm-1;最优部件刚度匹配方案所对应的轨道结构整体刚度为82kN·mm-1。

The previous calculation methods for track stiffness could only work out the value range or lower limit for the static stiffness of rail pad,but couldn＇t determine the overall track stiffness.The coupling dynamic model of freight car with 32.5taxle load and track system was constructed by the large wheel-rail dynamics software NUCARS.With the analysis method of dynamic sensitivity coefficient,the dynamic characteristics of vehicles and track system under various stiffness combinations of track structure components were analyzed to study the reasonable track stiffness for heavy haul railway under the action of freight car with 32.5taxle load.Results showed that the vertical displacement of rail as well as the pressure of both the track bed and rail pad was sensitive to the stiffness of rail pad.Both the vertical displacement and vertical acceleration of sleeper as well as the pressure of track bed were sensitive to the stiffness of track bed.The objective function was established to minimize the comprehensive effect of track dynamic characteristics.The optimal stiffness matching scheme of track structure components selected for heavy haul railway under the action of freight car with 32.5taxle load was that the stiffness of rail pad was 140kN·mm-1,the stiffness of track bed was 150kN·mm-1 and the overall stiffness of track structure corresponding to the optimal stiffness matching scheme was 82kN·mm-1.