40吨轴重下轨枕承轨槽接触应力分析  

ANALYSIS OF THE PRESSURE DISTRIBUTION ON RAIL SEAT OF CONCRETE SLEEPERS UNDER 40- TONNE AXLE LOAD

作　　者：安博洋[1] 杨吉忠[2] 刘超[1] 赵鑫[1] 温泽峰[1] 金学松[1] 

机构地区：[1]西南交通大学牵引动力国家重点实验室,成都610031 [2]中铁二院工程集团有限责任公司,成都610031

出　　处：《机械强度》2016年第2期311-316,共6页Journal of Mechanical Strength

基　　金：国家自然科学基金(U1361117;51305361);中国博士后科学基金资助项目(2013M540717);四川省应用基础研究计划项目(2013JY0040)资助~~

摘　　要：从轨道系统静态受力分析的角度出发,建立了考虑轨下胶垫弹性接触的三维轨道有限元模型,研究了40吨轴重作用下的轨道结构响应,重点分析了不同服役状态下轨枕承轨槽处的静态应力水平,为我国未来大轴重轨道结构设计提供数据支持。通过与经典轨道结构静态模型计算结果对比,验证了本文建立的轨道结构有限元模型的合理性。计算结果表明:(1)在40吨轴重车辆的作用下,我国现有的重型轨道结构满足运行要求,但是,路基顶面应力超过其承载能力;(2)随着横向轮轨力幅值的增加,轨下胶垫-承轨槽接触面的横向宽度逐渐减小,纵向长度不受影响,最大压应力显著增加且发生位置相应地向轨枕外端移动;(3)典型横向轮轨力水平下,轨下胶垫的刚度由80 MN/m增加到200 MN/m时,承轨槽压应力分布变化较明显,而当进一步增加到1 300 MN/m,其影响可以忽略;(4)不考虑动态系数变化影响的前提下,扣件松脱会降低承轨槽处的压应力水平,轨下胶垫-承轨槽接触面的形状因约束减少而变得更加不规则。A 3D static finite element（ FE） model of a heavy haul track is developed to study the deformation of the track structure under an axle load of 40 tonnes,in which the rail-railpad-sleeper contact is simulated in detail. Focus of analysis is especially placed on the pressure distribution on the rail seat of concrete sleepers,which provides valuable data for future designs of heavy haul track structures of 40- tonne axle load. The FE model is first validated by comparing the calculated results with those of a traditional simplified algorithm. More results have shown that（ 1） the typical heavy haul track structure in China can meet the requirements of 40- tonne axle load,but the stress on the top of subgrade exceeds the bearing capacity considered in normal design;（ 2） with the increase of the lateral wheel-rail contact force,the width（ along the lateral） of the contact patch between the railpad and the sleeper decreases and the length keeps almost unchanged,thereby the maximum pressure increases and its location moves towards the field side in the lateral;（ 3） Under the typical wheel-rail contact forces,the pressure distribution on the rail seat changes significantly when the stiffness of the railpad increases from 80 MN / m to 200 MN / m,while un-affected as the stiffness further increases to 1300 MN / m;（ 4） Assuming a constant dynamic amplification factor,the pressure on the rail seat decreases as the rail fastening system fails,and correspondingly,the shape of contact patch between the rail pad and the sleeper becomes more irregular due to less constraints.

关 键 词：40吨轴重 重载铁路 轨下胶垫 承轨槽接触应力 有限元模型 

分 类 号：U213.34[交通运输工程—道路与铁道工程]