1Example57TitleRahmen(plate-frame)bridgesubjectedtoamovingload(MovingLaodModuleavailableuponrequest)DescriptionAnalyzearahmen(plate-frame)bridgeunderamovingload.Findthemaximummoments.Refertothefigureshownbelow.StructuralgeometryandanalysismodelVerificationExample2ModelAnalysisType3-DmovingloadanalysisUnitSystemm,tonfDimensionLength18mElementPlateelement(Thicktype)MaterialConcreteModulusofelasticityE=2.1×106tonf/m2Poisson’sratioν=0.167SectionPropertyThicknessUpperplate0.25mPierandabutment0.30mBoundaryConditionNodes76~80,91~95and106~110;ConstrainallDOFs.(Fixedsupports)LoadCaseMovingloadsDB-24andDL-24specifiedintheMOCTstandardspecificationforbridgesareapplied.Example573ResultsDisplacementsVerificationExample4Mxxinfluencesurfacediagramfortheelement15duetoDB-24(k-node)Mxxinfluencesurfacediagramfortheelement18duetoDB-24(k-node)Example575MaximumpositivemomentofthestructureintheXdirectionduetoDB-24(Mxx)MaximumnegativemomentofthestructureintheXdirectionduetoDB-24(Mxx)VerificationExample6ComparisonofResultsCalculationofthemaximumnegativeandpositivemomentsMxxforthestructure•Maximumpositivemoment:Nodes30;occursattheelementduetoDB-24Maximumpositivemomentoftheelement(Node30)CalculationofthepositivemomentMxxduetoDB-24Mxx=∑(Concentratedload×Valueofthemomentinfluencesurface×Impactcoefficient)=(4.8×0.005222+19.2×0.005832+19.2×0.005832)×1.300=8.632tonf⋅mPositivemomentMxxduetoDL-24Mxx=(∑Areaofpositivemoment×Valueofthemomentinfluencesurface×Unniformload+Valueofthemomentinfluencesurfaceofmaximumpositivemoment×Concentratedload(formomentcalculation))×Impactcoefficient=(2.23185×0.423333+0.33871×10.8)×1.300=5.984tonf⋅mMaximumpositivemoment:8.632tonf⋅m•Maximumnegativemoment:Node33;occursattheelementsduetoDB-24Calculationofthemaximumnegativemomentoftheelement(Node33)PositivemomentMxxduetoDB-24Mxx=∑(Concentratedload×Valueofthemomentinfluencesurface×Impactcoefficient)=(4.8×-0.055892+19.2×-0.26602+19.2×-0.143618)×1.300=-10.573tonf⋅mPositivemomentMxxduetoDL-24Mxx=(∑Areaofnegativemoment×Valueofthemomentinfluencesurface×Uniformload+Valueofthemomentinfluencesurfaceofmaximumnegativemoment×Concentratedload(formomentcalculation))×Impactcoefficient=(-4.1477×0.423333+-0.26602×10.8)×1.300=-6.04175tonf⋅mMaximumnegativemoment:-10.573tonf⋅mExample577Unit:m,tonfMomentduetoDB-24MomentduetoDB-24ResultLocation(Element-Node)MomentLocation(ElementNode)MomentPositive-308.632-305.984Maximummoment(Mxx)Negative-33-10.573-33-7.023Positive-306.190-304.130Maximummoment(Mxx)Negative-33-1.750-33-1.170Positive-339.448-337.691Maximumshearforce(Vxx)Negative-33-9.448-33-7.691Positive-493.943-303.509Maximumshearforce(Vxx)Negative-30-3.943-30-3.509Positive50.00133650.005841Maximumverticaldisplacement(Dz)Negative30-0.00118430-0.009358Positive9312.25019310.1488Maximumverticalreaction(Fz)Negative78-0.258978-0.2519Reference“StandardSpecificationforBridges”,MOCT(KoreanMinistryofConstructionandTransportation),1996
