1Example54TitleTensileforcesofcablemembersinacablestayedbridgeDescriptionGivenisacablestayedbridgesubjectedtoauniformlydistributedload.Determinetherequiredinitialtensileforcesinthecableelementssuchthatthehorizontaldisplacementatthetopofthemaintower(NodeA)andtheverticaldisplacementsofthenodesBandCareallzeros.StructuralgeometryandanalysismodelVerificationExample2ModelAnalysisType2-DstaticanalysisUnitSystemm,tonfDimensionLength160mHeight90mElementMaingirderandmaintowerBeamelementCableTrusselementMaterialSteelModulusofelasticityE=2.1×107tonf/m2Poisson’sratioν=0.3SectionPropertyCableRadius0.25mMaingirderBox3×20×0.03/0.05mMaintowerBottomBox10×2×0.05/0.05mTop(Taperedsection)I-EndBox10×2×0.05/0.05mJ-EndBox5×2×0.05/0.05mBoundaryConditionNode1;ConstrainDx,Dy,andDz.(Hingesupport)Node5;ConstrainDy,andDz.(Rollersupport)Node6;ConstrainallDOFs(Fixedsupport)Example543LoadCaseAunittensileforceisappliedtoeachcableLoadCase1;Atensileforce,1.0,isappliedtothetrusselement.LoadCase2;Atensileforce,1.0,isappliedtothetrusselement.LoadCase3;Atensileforce,1.0,isappliedtothetrusselement.LoadCase4;Auniformload,ω=9ton/misdistributedinthe-Zdirection.CompositionofequationsConstituteequationsinordertofindloadcombinationfactors.Thenumberofunknownloadcombinationfactorsandrequiredlimitationsshouldbeequal.Limitation;Setthehorizontaldisplacementatthenode7andtheverticaldisplacementsatthenodes3and4tozero.VerificationExample4ResultsLoadCombinationFactorsCombinedZ-displacementsofthestructureExample545CombinedX-displacementsofthestructureResultsofMIDAS/GenUnit:m,tonfLoadCaseLoadcombinationfactorLimitationAftercombination11496.47217Verticaldisplacementatthenode30.02565.86749Verticaldisplacementatthenode40.03722.65741Horizontaldisplacementatthenode70.0
