道桥工程中英文对照外文翻译文献Word格式.docx
- 文档编号:17831439
- 上传时间:2022-12-11
- 格式:DOCX
- 页数:30
- 大小:746.34KB
道桥工程中英文对照外文翻译文献Word格式.docx
《道桥工程中英文对照外文翻译文献Word格式.docx》由会员分享,可在线阅读,更多相关《道桥工程中英文对照外文翻译文献Word格式.docx(30页珍藏版)》请在冰豆网上搜索。
Abstract:
Aconvenientapproachisproposedforanalyzingtheultimateloadcarryingcapacityofconcretefilledsteeltubular(CFST)archbridgewithstiffeninggirders.AfibermodelbeamelementisspeciallyusedtosimulatethestiffeninggirderandCFSTarchrib.Thegeometricnonlinearity,materialnonlinearity。
influenceoftheconstructionprocessandthecontributionofprestressingreinforcementarealltakenintoconsideration.Theaccuracyofthismethodisvalidatedbycomparingitsresultswithexperimentalresults.Finally,theultimatestrengthofanabnormalCFSTarchbridgewithstiffeninggirdersisinvestigatedandtheeffectofconstructionmethodisdiscussed.Itisconcludedthattheconstructionprocesshaslittleeffectontheultimatestrengthofthebridge.
Keywords:
Ultimatestrength,Concretefilledsteeltubular(CFST)archbridge,Stiffeninggirder,Fibermodelbeamelement,
Constructionprocess
doi:
10.1631/jzus.2007.A0682
NTRODUCTION
Withtheincreasingapplicationsofconcretefilledsteeltubular(CFST)structuresincivilengi-neeringinChina,archbridgeshavebecomeoneofthecompetitivestylesinmoderatespanorlongspanbridges.TakingtheFuxingBridgeinHangzhou
(Zhaoetal.,2004),andWushanBridgeinChongqing(Zhangetal.,2003),China,asrepresentatives,thestructuralconfiguration,thespanandconstructionscaleofsuchbridgeshavesurpassedthoseofexistingCFSTarchbridgesintheworld.Therefore,itisofgreatimportancetoenhancethetheoreticallevelinthedesignofCFSTarchbridgesforsafetyandeconomy.
hecalculationofultimatebearingcapacityisasignificantissueindesignofCFSTarchbridges.Asanarchstructureisprimarilysubjectedtocompres-siveforces,theultimatestrengthofCFSTarchbridgeisdeterminedbythestabilityrequirement.Anumberoftheoreticalstudieswereconductedinthepasttoinvestigatethestabilityandload-carryingcapacityofCFSTarchbridges.Zengetal.(2003)studiedtheloadcapacityofCFSTarchbridgeusingacompositebeamelement,involvinggeometricandmaterialnonlin-earity.Zhangetal.(2006)derivedatangentstiffnessmatrixforspatialCFSTpoleelementtoconsiderthegeometricandmaterialnonlinearitiesunderlarge
displacementbyco-rotationalcoordinatemethod.Xieetal.(2005)proposedanumericalmethodtodeterminetheultimatestrengthofCFSTarchbridgesandrevealedthattheeffectoftheconstitutiverelationofconfinedconcreteisnotsignificant.Huetal.(2006)
investigatedtheeffectofPoisson’sratioofcoreconcreteontheultimatebearingcapacityofalongspanCFSTarchbridgeandfoundthatthebearingcapacityisenhancedby10%ifthePoisson’sratioisvariable.
Ontheotherhand,manyexperimentalstudiesontheultimatestrengthofnakedCFSTarchriborCFSTarchbridgemodelhadbeenconducted.ExperimentalstudiesonCFSTarchribunderin-planeand
out-of-planeloadswerecarriedoutbyChenandChen2000)andChenetalmetricalnonlinearitywassignificantfortheout-of-planestrengthandlesssignificantforthein-planestrength.Cuietal.(2004)introducedaglobalmodeltestofaCFSTarchbridgewithspanof308m,andsuggestedthattheinfluenceofinitialstress
shouldbeconsidered.
TheabovepapersmainlyfocusedontheultimatestrengthofCFSTnakedarchribsorCFSTarchbridgeswithfloatingdeck.NoattemptwasmadetostudytheultimatestrengthofCFSTarchbridgeswithstiffeninggirderswhosenonlinearbehaviorandCFSTarchshouldbesimulatedduetotheredistributionofinnerforcesbetweenarchribsandstiffening
girders.Ingeneral,stiffeninggirderscanbeclassifiedintosteelgirder,PC(prestressingconcrete)girderandteel-concretecombinationgirder.ItismostdifficulttosimulatethenonlinearbehaviorofPCgirder,duetotheinfluenceofprestressingreinforcement.Incontrasttosteelorsteel-concretecombinationbeam,theprestressingreinforcementsinPCgirdersnotonlyofferstrengthandstiffnessdirectly,buttheirtensiongreatlyaffectsthestiffnessanddistributionoftheinitialforcesinthestructure.Theaimsofthispaperare
(1)topresentanelas-tic-plasticanalysisoftheultimatestrengthofCFSTarchbridgewitharbitrarystiffeninggirders;
(2)tostudytheultimateload-carryingcapacityofacomplicatedCFSTarchbridgewithabnormalarchribsandPCstiffeninggirders;
and(3)toinvestigatetheeffectofconstructionmethodsontheultimatestrengthofthestructure.
ANALYTICALTHEORY
Elasto-plasticlargedeformationofPCgirderelementTheelasto-plasiclargedeformationanalysisofPCbeamelementsisbasedonthefollowingfundamentalassumptions:
(1)Aplanesectionoriginallynormaltotheneutralaxisalwaysremainsaplaneandnormaltotheneutralaxisduringdeformation;
(2)Thesheardeformationduetoshearstressis
neglected;
(3)TheSaint-Venanttorsionalprincipleholdsin
(4)Theeffectofshearstressonthestress-strainrelationshipisignored.Thecross-sectionofaPCboxgirderwithonesymmetricaxisisdepictedinFig.1,where,Gandsdenotethegeometrycenterandtheshearcenterre-spectively.Accordingtothefirstandthethirdas-sumptionslistedabove,thedisplacementincrements
ofpointA(x,y)inthesectioncanbeexpressedintermsofthedisplacementincrementsatthegeometrycenterandtheshearcenteras
whereKtoristhecoefficientfactorwhichisrelatedtothegeometryshapeofthegirdercross-section.
Similarto3Delasticbeamtheory,thedisplacementincrementofthegirdercanbeexpressedintermsofthenodaldisplacementincrementsas
inwhichLdenotestheelementlength,andzistheaxialcoordinateofthelocalcoordinatesystemofanelement.Then,thedisplacementvectorofanysectionoftheelementcanbewrittenas
where∆uisthedisplacementvectorofanysectionofthebeamelement,Nistheshapefunctionmatrixand∆ueisthedisplacementvectoroftheelementnode.Theyarerespectivelyexpressedas
AccordingtoEq.
(2),thelinearstraincanbeex-pressedas
inwhichBListhelinearstrainmatrixoftheelement
Correspondingly,thenonlinearstrainmaybeexpressedas
whereBNListhenonlinearstrainmatrixoftheele-
ment
Thestressincrement∆σcanbeapproximated
usingthelinearstrainincrementas
whereDisthematerialpropertymatrix.Neglectingtheinfluenceoftheshearstrain,Dcanbeexpressed
whereE(ε)isthetangentmodulusofthematerialwhichisdependentonthestrainstate,andGistheelasticshearingmodulusregardedasaconstant.Accordingtotheprincipleofvirtualwork,wehaveinwhichσand∆σarethestressvectorandstressincrementofthecurrentstate,qandParethedis-tributedloadandconcentratedloadvector,∆qand∆P
aretheincrementsofdistributedloadandconcen-tratedload,δ∆uandδ∆εarethevirtualdisplacementandvirtualstrain,andVisthevolumeoftheelement.SubstituteEqs.(9),(11)and(14)intoEq.(16)andignoretheinfinitesimalvariable∆σ∆εN,wehave
where∆Feistheincrementofelementloadvectorcorrespondingto∆ue,theelementdisplacementvec-tor.KepandKσaretheelasto-plasticandgeometricstiffnessmatrixesofthebeamelementrespectivelyasfollows
Thedistributionofelasticandplasticzonesisnon-uniformintheelement,andvariesduringde-formation.ItisverydifficulttopresentanexplicitexpressionofthepropertymatrixDforthewholesection.Hence,thesectionisdividedintomanysubareas,asshowninFig.2,andthefibermodelis
adoptedtocalculatetheelement’sstiffnessmatrix,i.e.Obviously,ifthenumberofsubareasissuffi-cientlylarge,theresultofEq.(19)willapproachtheexactsolution.ThevalueofKepiscalculatedusingnumericalintegration,withDibeingregardedasi.TocomputethegeometricstiffnessmatrixKσ,thenormalstressshouldbeexpressedintermsofaxialforceandbendingmoment,whichactuallyhasverylittlecontributiontothegeometricstiffness,sowhereNistheaxialforce,andAisthesectionalarea.
PrestressingreinforcementelementThereinforcedbarsparalleltothebeamaxismayberegardedasfibers,whosecontributionstothe
stiffnesscouldbereadilyaccountedforinEq.(19).Thecontributionstothestiffnessfromthosenotpar-alleltothebeamandtheprestressingreinforcement(PR),willhoweverbecalculatedinthefollowingsection.Thedisplacementincrementoftwoendsofthe
prestressingreinforcementinFig.3canbeexpressedbyEq.(21):
nwhichkepandkσarerespectivelytheelasto-plasticandthegeometricstiffnessmatrixes,∆δisthenodaldisplacementvector,and∆fisthenodalforcevectoroftheprestressingreinforcementelementinthelocalcoordinatesystem.AccordingtoFig.4,∆δand∆f
canbewrittenintheformThenthestiffnessmatrixep(k+k)
σoftherein-accordingly.CFSTarchrib,steelgirderorsteel-concretegirderelementThefibermodelmentionedabovecanalsobeusedtosimulatetheCFSTarchrib,steelstiffening
girderorsteel-concretecompositestiffeninggirder,withsimilarelasto-plasticstiffnessmatrixandstiff-nessequation.Thedetaileddescriptionofthedeductioncanbefoundin(Xieetal.,2005).However,fortheCFSTarchrib,thestress-strainrelationofstructureisverycomplexduetothecom-binedinfluenceoftheconfinedconcreteandoutersteeltube.Inthispaper,thefollowingstress-strainrelationconsideringtheconfinementeffectofthesteeltubering(Han,2000)isadopted:
whereσytandσycaretheyi
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 工程 中英文 对照 外文 翻译 文献