資源描述:
《軌枕支撐硬點(diǎn)對軌枕動力響應(yīng)的影響.doc》由會員上傳分享,免費(fèi)在線閱讀,更多相關(guān)內(nèi)容在行業(yè)資料-天天文庫。
1、軌枕支撐硬點(diǎn)對軌枕動力響應(yīng)的影響肖新標(biāo)金學(xué)松溫澤峰[摘要]建立了基于Timoshenko梁模型的車輛/軌道耦合動力學(xué)模型,分析軌枕支撐硬點(diǎn)對軌枕動力響應(yīng)的影響。軌道采用三層彈性離散點(diǎn)支撐模型,鋼軌被視為離散軌枕支撐上的無限長Timoshenko梁。通過假設(shè)軌道下軌枕垂向支撐高度沿縱向非均勻分布來模擬軌枕支撐硬點(diǎn),采用移動軌下支撐模型來分析其對系統(tǒng)動力響應(yīng)的影響。模型中考慮鋼軌橫向、垂向和扭轉(zhuǎn)運(yùn)動對輪軌滾動接觸蠕滑率的影響,利用Hertz法向接觸理論和沈氏蠕滑理論分別計(jì)算輪軌法向力及輪軌滾動接觸蠕滑力。應(yīng)用新型顯式積分法對車輛/軌道耦合動力學(xué)系統(tǒng)運(yùn)動方程
2、進(jìn)行求解。通過數(shù)值方法,分析計(jì)算了不同的軌枕支撐硬點(diǎn)個數(shù)和高度對車輛/軌道耦合系統(tǒng)響應(yīng)的影響。結(jié)果表明,軌枕支撐硬點(diǎn)對車輛系統(tǒng)動力響應(yīng)的影響很小,對軌道系統(tǒng)動力響應(yīng)的影響較顯著,尤其是軌枕的動力響應(yīng)。隨著軌枕支撐硬點(diǎn)高度的增加,支撐硬點(diǎn)處鋼軌/軌枕間作用力和最靠近硬點(diǎn)區(qū)段的軌枕支撐處的鋼軌/軌枕拉力迅速增大,將加速軌枕、軌下墊層及鋼軌扣件狀況的惡化。而支撐硬點(diǎn)個數(shù)對系統(tǒng)動力響應(yīng)的影響很小。[關(guān)鍵詞]軌枕;軌道;車輛;耦合動力學(xué);動力響應(yīng);硬點(diǎn)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