轨枕支撑硬点对轨枕动力响应的影响.doc

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1、轨枕支撑硬点对轨枕动力响应的影响肖新标金学松温泽峰[摘要]建立了基于Timoshenko梁模型的车辆/轨道耦合动力学模型，分析轨枕支撑硬点对轨枕动力响应的影响。轨道采用三层弹性离散点支撑模型，钢轨被视为离散轨枕支撑上的无限长Timoshenko梁。通过假设轨道下轨枕垂向支撑高度沿纵向非均匀分布来模拟轨枕支撑硬点，采用移动轨下支撑模型来分析其对系统动力响应的影响。模型中考虑钢轨横向、垂向和扭转运动对轮轨滚动接触蠕滑率的影响，利用Hertz法向接触理论和沈氏蠕滑理论分别计算轮轨法向力及轮轨滚动接触蠕滑力。应用新型显式积分法对车辆/轨道耦合动力学系统运动方程

2、进行求解。通过数值方法，分析计算了不同的轨枕支撑硬点个数和高度对车辆/轨道耦合系统响应的影响。结果表明，轨枕支撑硬点对车辆系统动力响应的影响很小，对轨道系统动力响应的影响较显著，尤其是轨枕的动力响应。随着轨枕支撑硬点高度的增加，支撑硬点处钢轨/轨枕间作用力和最靠近硬点区段的轨枕支撑处的钢轨/轨枕拉力迅速增大，将加速轨枕、轨下垫层及钢轨扣件状况的恶化。而支撑硬点个数对系统动力响应的影响很小。[关键词]轨枕；轨道；车辆；耦合动力学；动力响应；硬点EffectofHardSpotondynamicresponseofRailwaySleeperXiaoXin

3、-biao,JinXue-song,WenZe-feng(StateKeyLaboratoryofTractionPower,SouthwestJiaotongUniversity,Chengdu610031,China)[Abstract]Inordertoinvestigatetheeffectofhardspotondynamicresponseofrailwaysleeper,avehicle-trackcouplingdynamicmodelisestablished,inwhichthetrackismodeledasa3-layerdis

4、creteelasticsupportmodelandtherailsareassumedtobeTimoshenkobeamsrestingonthediscretesleepers.Thehardspotofsleepersupportundertherailsissimulatedbynon-uniformheightofsleepersupportalongthetrack,anditseffectonthecouplingdynamicsofthevehicleandtrackistakenintoconsiderationbytheback

5、wardmovingsleepers.Inthedynamicmodel,theeffectoftheverticalandlateralmotionsofthetrackonthewheel-railcreepagesistakenintoaccount.Thenormalforcesofwheel/railarecalculatedbyHertziancontacttheoryandthecreepforcesofwheel/railinrollingcontactaredecidedbythenonlinearcreeptheoryofShene

6、tal.Themotionequationsofthevehicle/trackcouplingsystemaresolvedwiththenewexplicitintegrationmethod.Effectsofnumberandheightofhardspotondynamicresponseofcoupledvehicle/tracksystemareinvestigated.Thenumericalresultsindicatethathardspotgreatlyaffectsdynamicresponseoftracksystemrath

7、erthanvehiclesystem,especiallyofrailwaysleeper.Withincreasingtheheightofhardspot,therail/sleeperpressureforcesintheregionofhardspotandtherail/sleepertensionforcesinthenearestsleepertotheregionincreasequickly,whichwilldeterioratetherailwaysleeper,rail-padandrailfastening.Thedynam

8、icresponseofvehicle-trackcouplingsystemarenotse