轨道横向力与纵向力

Chapter28Track-TrainDynamicsProblemLateralForcesHighCenterofGravityCarsVerticalForcesLoadedandEmptyCarsTypesofLateralMovementLateralBendingandBendingStressLateralMovementTiltorTwistLateralPhenomenaTrainActionDerailmentWheelClimbingRailOverturningBrakeAction–assumesstatusofalongandflexiblebeamincompression,arelativelyunstablestateQuicktake-upofslackinalongtraincanalsoexertlateralpressureTrainAction(Cont’d)ReverseCurves“Chording”theCurveTruckHuntingDerailmentCausesOperatingError(Transportation)MechanicalError(Mechanical)TrackError(Engineering)OraCombinationofAbove~ConductRootCauseAnalysis~L/VRatioRatioofthelateralcomponenttotheverticalcomponentofthewheelload.Asratioincreases,tendencytoderailincreasesLateralSlipLoadApplicationBallastSectionDesignL/VTrackRestraintRatioTrackDesignFactorsTrainForcesCarWeightProblemsfromModernCarsRockandRollMoreprevalentonjointedtrackJointsevery19.5feet–inducedoscillationCarbodyspringshavenaturalfrequencyofoscillationAtspeedsbetween12and20mphfrequenciesareadditiveIfsquarejoints–bounceSolutions:Don’tsetsustainedspeedlimitsbetween12-20mphUsesnubbingdevicesoncarsUseCWRRock&RollTruckHuntingLongCarsTransportationTechnologyCenterPueblo,ColoradoTestTracksandOtherResearchFacilities