engineering mechanics institute international …...engineering mechanics institute international...

2 – 4 November, 2018

Tongji University, Shanghai, China

Engineering Mechanics Institute

International Conference 2018

Sponsored by

Tongji University

National Natural Science Foundation of China

The Chinese Society of Theoretical and Applied Mechanics

Architectural Society of China

Shanghai Society of Theoretical and Applied Mechanics

Chinese Society for Vibration Engineering

1687

ASCE

EMI ENGINEERINGMECHANICSINSTITUTE


International Conference 2018 November 2-4 Tongji University

1

TableofContents

WELCOME FROM THE EMI PRESIDENT ....................................................................................... 2

Background and Aim ..................................................................................................................... 3

Conference Co-Chairs .................................................................................................................... 3

EMI Administrative Staff ............................................................................................................... 3

2018 EMI Board of Governors ...................................................................................................... 3

Committee ...................................................................................................................................... 4

Poster Session ................................................................................................................................ 6

Conference Venue .......................................................................................................................... 7

Contacts .......................................................................................................................................... 8

Program ........................................................................................................................................... 9

PlenaryLectures ............................................................................................................................ 24

Abstracts ........................................................................................................................................ 32

MS1: Cementitious Materials: Experiments and Modeling across the Scales ................................... 33

MS2: Modeling Time-Dependent Behavior and Deterioration of Concrete ...................................... 49

MS3: Instabilities and Bifurcations in Solids, Structures and Soft Materials ..................................... 57

MS4: Computer Vision-based Studies in Structural Health Monitoring ............................................. 80

MS5: Nonlinear Stochastic Structural Dynamics Methodologies for Complex Engineering Systems 83

MS6: Damage Modelling of Engineering Structures .......................................................................... 86

MS7: Non-Deterministic Modelling and Uncertainty Management in Structural Dynamics and

Vibroacoustics .................................................................................................................................... 93

MS8: Computational Modeling of Damage and Failure in Solids and Structures ............................ 106

MS9: Reliability Analysis of Engineering Structures under Disastrous Excitations .......................... 110

MS10: Damage and Fracture of Brittle and Quasi-Brittle Materials ................................................ 119

MS12: Dynamic Analysis and Seismic Performance of Structures under Strong Earthquake Ground

Motions ............................................................................................................................................ 124

MS13: Damage and Failure Modeling and Analysis of Concrete and Structures ............................. 143

MS14: Uncertainty Quantification and Reliability-based Performance Evaluation ......................... 153

MS15: Environmental Effects on the Properties of Cementitious Materials: Experiments, Modeling

and Simulation ................................................................................................................................. 183

MS16: Fluid-Structure Interactions and Flow-Induced Motions ...................................................... 194

MS17: Stability and Failure of Structures and Materials.................................................................. 200

MS18: Computational Modeling of Advanced Materials and Novel Structural Systems for Hazard

Mitigation ......................................................................................................................................... 214

GS1: Stochastic Mechanics and Structural Reliability ...................................................................... 221

GS2: Computational Mechanics ....................................................................................................... 227

GS3: Wood Mechanics ..................................................................................................................... 238

GS4: Structural Mechanics and Simulation ...................................................................................... 243

GS5: Bio-Mechanics and Bone Mechanics ....................................................................................... 253

The 5th EMI International Conference 2019 .......................................................................... 255

Join EMI Today ........................................................................................................................... 257



2

WELCOME FROM THE EMI PRESIDENT

DearParticipantsofthe2018EMIInternationalConference,

AsIstartmysecondyearofserviceasPresidentofEMI,Iwouldliketoexpressmy

sincere thanks to the extraordinary dedication, commitment and hard work of the

BoardofGovernors,theEMIstaff,thetechnicalcommittees,andourmembersinthe

U.S.andaroundtheglobe.OnbehalfofEMI,IwouldliketothankProf.JieLi(Tongji

University),ConferenceChair,Prof.JianbingChen(TongjiUniversity),Prof.Xiaodan

Ren (Tongji University), and Prof. Jian-Ying Wu (South-China University of

Technology),Co-ChairsoftheLocalOrganizingCommittee,fororganizingandhosting

thisyear'sEMIInternationalConference.Iwouldalsoliketothankallthemembers

oftheLocalOrganizingCommitteeandallthemembersoftheInternationalScientific

Committeefortheirvaluablecontributionstothesuccessoftheconference.

The ever-increasing attendance at the EMI conferences reflects EMl's growing

reputationasthepremiervenueforengineeringmechanics.Inadditiontothevibrant

technicalprogramsofferedoverthepasttenyearsatEMIconferences,ourInstitute

hasexperiencedahealthyincreaseinitsmembershipandhasgreatlybenefitedfrom

the stellar reputation of our flagship publication, the ASCE Journal of Engineering

Mechanics, under the inspiring editorship of Prof. Roberto Ballarini (University of

Houston).

Iinviteyoutogetmoreinvolvedwithourinstitute.EMIwillfurthergrowandthrive

only if the requisite hard work is shared among its members. Opportunities for

engagement includepublication intheASCEJournalofEngineeringMechanicsand

theLectureNotesinMechanicsSeries,activeparticipationontechnicalcommittees,

organizationofconferencesessionsandsymposia,engagementintheEMIindustry

collaboration,deliveryofwebinars,andseekingleadershiprolesoncommitteesand

theBoardofGovernors.

Iwishyouanenjoyableandproductiveconference.

Yourstruly,

ProfessorGeorgeDeodatis

ColumbiaUniversity,NewYorkCity



3

Background and Aim

CreatedonOctober1,2007,theEngineeringMechanicsInstitute(EMI)replacestheformer

ASCE Engineering Mechanics Division. EMI has two annual conferences, one in the United

Statesandanotherinternationally.Theseconferencesofferaplacetoexchangeideas,present

your work, and see what others are doing. The fundamental advances in engineering

mechanicsarehereondisplay.Theseconferencespresentpremieropportunitiestonetwork

with leaders in the field,expandyourhorizons,andestablishprofessionalrelationships to

advanceyourresearchandyourcareer.EMIconferencesalsoshowcasesomeofthebrightest

studentswhoparticipateinstudentcompetitions.

The 2018 EMI International Conference will be held at Tongji University, Shanghai, China

during Nov. 2-4th, 2018. This event will be a forum to present the newest findings and to

depict the future development in Engineering Mechanics as the core discipline of science-

enabledCivilEngineeringunderstoodinthebroadestsense.

Conference Co-Chairs

JieLi,TongjiUniversity

GeorgeDeodatis,ColumbiaUniversity

EMI Administrative Staff

AmarChaker,ASCE/EMI

VernaJameson,ASCE/EMI

2018 EMI Board of Governors

GeorgiosDeodatis,Ph.D.,F.EMI,M.ASCE,President

PolD.Spanos,Ph.D.,P.E.,NAE,F.EMI,Dist.M.ASCE,VicePresident

Jiun-ShyanChen,Ph.D.,F.EMI,M.ASCE,PastPresident

AmarA.Chaker,Ph.D.,F.AEI,F.EMI,F.ASCE,Secretary

SomnathGhosh,Ph.D.,Ph.D.,F.EMI,M.ASCE,Treasurer

GianlucaCusatis,Ph.D.,F.EMI,M.ASCE.Member

RaymondDaddazio,Sc.D.,P.E.,F.EMI,M.ASCE,Member

GlaucioH.Paulino,Ph.D.,F.EMI,M.ASCE,Member

AntoinetteTordesillas,Ph.D.,Aff.M.ASCE,Member



4

Committee

InternationalScientificCommittee

AhmerWadee ImperialCollegeLondon UK

Bao-FengHuang NanjingTechUniversity China

BernhardPichler TUWien-ViennaUniversityofTechnology Austria

CaoSun LouisianaStateUniversity USA

Chao-LieNing TongjiUniversity China

ChristianHellmich TUWien-ViennaUniversityofTechnology Austria

Da-XuZhang ShanghaiJiaoTongUniversity China

De-ChengFeng SoutheastUniversity China

DingWang YanshanUniversity China

Di-XiongYang DalianUniversityofTechnology China

FanKong WuhanUniversityofTechnology China

FanXu FudanUniversity China

Franz-JosefUlm MassachusettsInstituteofTechnology USA

GianlucaCusatis NorthwesternUniversity USA

GillesPijaudier-Cabot UniversitédePauetetdesPaysdel’Adour France

GiovanniDiLuzio PolitecnicodiMilano Italy

GüntherMeschke RuhrUniversityBochum Germany

Hai-YanHu BeijingInstituteofTechnology China

HerbertMang ViennaUniversityofTechnology;TongjiUniversity Austria

Hong-ZheDai HarbinInstituteofTechnology China

IoannisKougioumtzoglou ColumbiaUniversity USA

IoannisMitseas LeibnizUniversityHannover Germany

JanVorel CzechTechnicalUniversityinPrague Czech

JianYang ShanghaiJiaoTongUniversity China

JianZhang UniversityofCaliforniaatLosAngeles USA

Jian-BingChen TongjiUniversity China

Jian-GuoCai SoutheastUniversity China

Jian-YingWu SouthChinaUniversityofTechnology China

JieLi TongjiUniversity China

Ji-FengXu BeijingAeronauticalScience&TechnologyResearchInstitute China



5

Jing-QuanWang SoutheastUniversity China

Jin-GuangTeng HongKongPolytechnicUniversity China

Jiun-ShyanChen UniversityofCalifornian.SanDiego USA

JunXu HunanUniversity China

Li-HuaJin UCLA.California USA

LinWan-Wendner PolitecnicodiMilano Italy

LiuJin BeijingUniversityofTechnology China

LoriGraham-Brady JohnsHopkinsUniversity USA

MatteoBroggi LeibnizUniversitätHannover Germany

MengChu TongjiUniversity China

MichaelBeer LeibnizUniversitätHannover Germany

MichelPotier-Ferry UniversityofLorraine France

MohamedMoustafa UniversityofNevada. USA

MohammadJahanshahi PurdueUniversity USA

NingZhang McNeeseStateUniversity USA

RomanWan-Wendner UniversityofNaturalResourcesandLifeSciences Austria

Si-FengBi LeibnizUniversitätHannover Germany

Tian-CanHuang GuangzhouUniversity China

Xiao-DanRen TongjiUniversity China

Xiao-YingZhuang TongjiUniversity China

YangXiang WesternSydneyUniversity Australia

Yan-PingCao TsinghuaUniversity China

Yi-BinFu KeeleUniversity UK

Yong-ZhongHuo FudanUniversity China

You-BaoJiang ChangshaUniversityofScienceandTechnology China

ZdeněkBažant NorthwesternUniversity USA

Zhao-DongDing HeFeiUniversityofTechnology China

Zhen-HaoZhang ChangshaUniversityofScienceandTechnology China



6

LocalOrganizingCommittee

Co-Chairs

Jian-BingChen TongjiUniversity

Xiao-DanRen TongjiUniversity

Jian-YingWu South-ChinaUniversityofTechnology

Members

Xiang-LingGao TongjiUniversity Yan-PengWang TongjiUniversity

WeiLiu TongjiUniversity QingWang TongjiUniversity

Yong-BoPeng TongjiUniversity Ling-YingKong TongjiUniversity

HaoZhou South-ChinaUniversityofTechnology Zhi-QiangWan TongjiUniversity

Shi-XueLiang ZhejiangSCI-TECHUniversity Yu-PengSong TongjiUniversity

YeFeng TongjiUniversity Meng-ZeLyu TongjiUniversity

LuHai TongjiUniversity

Poster Session

PosterSessionwillbeheldattheB-flooroftheSino-FrenchCenterofTongjiUniversityduringthe

conference.PresentersshouldputupyourpostersonthemorningofNovember3th.



7

Conference Venue

Conferencevenue:TongjiUniversity

Address:1239SipingRoad,Shanghai,China

MapofVenue

Sino-FrenchCenter



8

Transportation

（1）FromPudongInternationalAirport(PVG)

☞byMetroLine2to“EastNanjingRoad”andtransferMetroLine10to“TongjiUniversity”stop(about100

minutes/RMB7.00)

☞byTaxi(about60minutes/RMB160.00)

（2）FromHongqiaoInternationalAirport(SHA)orHongqiaoRailwayStation

☞byMetroLine10tothe“TongjiUniversity”stop(about60minutes/RMB5.00)


（3）FromShanghaiRailwayStation

☞byMetroLine4to“HailunRoad”andtransferMetroLine10to“TongjiUniversity”stop(about40minutes

/RMB4.00)


（4）FromShanghaiSouthRailwayStation

☞byMetroLine3to“HongqiaoRoad”andtransferMetroLine10to“TongjiUniversity”stop(about70

minutes/RMB5.00)

☞byTaxi(50minutes/RMB90.00)

Contacts

Jian-BingChen,Professor

CollegeofCivilEngineering,TongjiUniversity,Tel:+86-13761804958,E-mail:[email protected]

Xiao-DanRen,AssociateProfessor

CollegeofCivilEngineering,TongjiUniversity,Tel:+86-15821525391,E-mail:[email protected]



9

Program



10

Time Venue

14:00—21:30Registration

The3rdfloorofKingswellHotelVIPRoom

19:00—21:00IceBreakerReception

The3rdfloorofKingswellHotelBallRoom

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Time Venue

8:00—18:00 Registration(Sino-FrenchCenterRoomC201)

8:30—8:50 WelcomingRemarks

8:50—9:00 GroupPhoto

PlenaryLectures

Chair(s):Prof.PolD.Spanos

9:00--9:40DesignofNewMaterialsandStructurestoMaximizeStrengthatProbabilityTail:ANeglectedChallengeforQuasibrittleandBiomimeticMaterials

Prof.ZdeněkP.Bažant-NorthwesternUniversity,USA

9:40--10:20EngineeringDynamicsofSoftMachines

Prof.Hai-YanHu-BeijingInstituteofTechnology,P.R.China

10:20--10:40 CoffeeBreak(The1stfloorofSino-FrenchCenter)

Sino-FrenchCenter

RoomC201Sino-FrenchCenter

RoomC401YifuBuilding

Room113Sino-FrenchCenter

RoomA401TongjiUniversityZhonghe

BuildingRoom1002TongjiUniversityZhonghe

BuildingRoom802

Session

MS3:Instabilitiesand

BifurcationsinSolids,StructuresandSoft

MaterialsChair(s):Yong-ZhongHuo

MS10:DamageandFractureofBrittleandQuasi-Brittle

MaterialsChair(s): Da-XuZhang

MS2:ModelingTime-DependentBehaviorandDeterioration

ofConcreteChair(s):LinWan-Wendner

MS14:UncertaintyQuantification

andReliability-basedPerformanceEvaluation

Chair(s):Zhen-HaoZhang

MS17:StabilityandFailureof

StructuresandMaterialsChair(s):XiangYang

Ji-FengXu

MS9:ReliabilityAnalysisof

EngineeringStructuresunderDisastrousExcitations

Chair(s):JunXu

10:40—10:55

A0121(Invited):WrinklingofSoft

Biomaterials

A0978:ImpactFractureSimulation

ofMonolithicandLaminatedGlassUsing

HybridDiscontinuaandContinuaMethod

A0042:ConcreteCreepModeling:

ApplicationtoSlabsonGround

A0131(Invited):AnalyzingComplex

SystemsunderEpistemicUncertainties

A0839(Invited):FailureandBuckling

AnalysesofCompositeLaminateswithCut-Outs:TheoryandExperiments

A0022(Invited):AProbabilisticAnalysisofa

PhenomenologicalModelforStructuralCollapse

Simulation

Xing-ErWang YaWei

10:55--11:10

A0857:ModellingofDamageandFractureofPlainWeave

CeramicMatrixCompositesunderUni-AixalTension

A0082:NumericalModule

DevelopmentfortheEntireProcessofRCDeterioration

duetoNon-UniformCorrosion

BoLi Da-XuZhang Zhao-ZhengMeng MichaelBeer Jian-XiangWang ChengChen

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11:10--11:25

A0342:Photo-ResponsiveSurface

WrinklingPatterns

A0863:PredictionofShear

DamageBehaviourofFibre-ReinforcedCeramic

MatrixTows

A0287:AgeDependentShear

ResistanceofReinforcedandPrestressedConcrete

A0644:ProbabilityDistrubutionoftheTimeIntervalBetween

TwoAdyacentRandomEventsoftheWiener

ProcessCrossingaBoundary

A0149:FrequencyAnalysisfor

VibratingBendingBeamsviaaNewStaticApproach

A0824:AssessingtheSpallingofTunnelLiningsSubjected

toFireLoading

Cong-HuaLu Da-XuZhang LinWan-Wendner Zhen-HaoZhang Zhen-YuChen Yi-MingZhang

11:25--11:40

A0250:MechanicsofNanofibers

PackinginVesicles:EffectsofFiberLength,Radius,

andElasticity

A0866:ValidationoftheCombinedFEM-DEMonModeIandIIConcreteRuptureSubjectstoSemi-CircularBending

A0708:ATheoreticalFramework

forCreepEffectAnalysisofAxialLoadedShortCFST

ColumnsunderHighStressLevels

A0222:MultiLevelMoving

ParticlesSimulationforReliabilityAssessmentwith

ApproximateLimiteStateFunctions

A0586:BucklingofBeamsSubject

toInfluenceofSurfaceStresses

A0349:StochasticDynamic

ResponseAnalysisandReliabilityAssessmentof

Non-LinearStructuresunderFullyNon-Stationary

GroundMotions

XinYi Xu-DongChen Shi-WeiLi CarstenProppe FengLin JunXu

11:40--11:55

A0397:AConsistentFinite-StrainPlateTheoryforGrowth-

InducedDeformationsandInstabilitiesofSoftMaterial

Samples

A0034:InfluenceofAsphalt

MixtureTypeonStrengthSizeEffectStatisticsatLow

Temperature

A0593:ProbabilisticModeloftheYieldingStrengthforthe

CorrodedRebars

A0949:StructuralFailureMode

IdentificationandReliabilityAnalysisbased

onMulti-ResponseSurfaceMethod

A0380:PLY-GAPEffectson

BucklingBehaviorofCompositeConicBarrelby

AutomatedFiberPlacement

A0347:SimulationofStationary

Non-GaussianVectorProcesswithinWave-

PassageEffectbasedonSpectralRepresentation

Method

JiongWang AugustoCannoneFalchetto Xiang-LingGao ZhaoChen Tian-LiangQin Yong-XinWu

11:55--12:10

A0054:PatternTransitionsina

SoftCylindricalShell

A0098:ConcreteShearWalls

AffectedbyAlkali-SilicaReactionPartI:Testing

A0549:StudyonMechanical

PropertiesandDamageAssessmentforCollided

Concrete

A0590:ThermalPostbuckling

BehavioursofFunctionallyGradedNanocomposite

Plates

A0538:ImpactofInitialDamage

PathandSpectralShapeonAftershockCollapse

FragilityofRCFrames

FanXu ShamimSheikh X.Y.Liu YinFan Xiao-HuiYu

12:20--13:30 Lunch(The1stfloorofKingswellHotelSunshineCoffeeShopandthe3rdfloorofKingswellHotelNo.3Room)

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Sino-FrenchCenterRoomC201

14:00--14:40

PlenaryLectureChair(s):Prof.RobertoBallarini

MechanicsofinterfacesinFRP-strengthenedstructures

Prof.Jin-GuangTeng-SouthernUniversityofScienceandTechnology,P.R.China

Sino-FrenchCenter





BuildingRoom1002TongjiUniversityZhonghe

BuildingRoom802

Session



MaterialsChair(s):Xi-QiaoFeng

MS1:CementitiousMaterials:

ExperimentsandModelingAcrosstheScales

Chair(s):BernhardPichler

MS12:DynamicAnalysisand

SeismicPerformanceofStructuresunderStrong

EarthquakeGroundMotions

Chair(s):ErtugrulTacirogluYi-QiangXiang


andReliability-basedPerformanceEvaluationChair(s):MichaelBeer

MS17:StabilityandFailureof

StructuresandMaterialsChair(s):ZhengLi

Ji-FengXu

MS9:ReliabilityAnalysisof

EngineeringStructuresunderDisastrousExcitations

Chair(s):DingWang

14:50--15:05

A0154(Invited):MorphologicalEvolutionofBuckle-Delamination:fromTelephoneCordBlisterto

Beyond

A0919:Microstructural

CharacterizationoftheSpunCastConcrete

A0105:DimensionalSeismicResponsesofShear-

FlexuralBeamandSelf-SimilarInterstoryDrift

Spectrum

A0915:RiskPriorityNumbersforVariousFailuresinBridges

A0681: Imperfectionsbydesign:interactivebucklingand

postbucklinginarchitectedmaterials

A0563:StructuralReliability

AnalysisUsingUQFEMSoftware

MaciejSobótka Gui-QiangGuo ChandrasekharPutcha NanHu Zi-QiWang

15:05--15:20

A0761:Time-SpaceDependent

StabilityAnalysisofShallowNatmTunnelswith

DiscontinuityLayoutOptimization

A0109:ANewApproachtoDesignExplicitTimeIntegration

AlgorithmwithNumerical

A0179:EfficientBridgeLifetime

AssessmentbyTrafficLoadModelUpdatingandSubset

Simulation

A0332:Characterizationof

nonlinearconstitutivebehaviorofceramic-based

compositeusingdigitalimagecorrelation

A0520:SeismicFragilityAnalysis

ofUrbanRoadNetwork-ACaseStudyonTangshan

City

YongNi Yi-MingZhang ShiLi He-QingMu Xiao-HuiJI DingWang

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15:20--15:35

A0493:PatternFormationin

CurvedFilm-SubstrateSystems

A0038:Macro-ScaleStrengthand

MicrostructureofZrW2O8CementitiousComposites

withTunableLowThermalExpansion

A0567:ModelingandPerformance

AssessmentofBase-IsolatedBuildings

A0912:AnalyticalSolutionfor

LocalBucklingStrengthofSquareCFTColumns

SubjectedtoEccentricCompression

A0473:CharacterizationforCompression-Shear

CombinedPropertiesofaCompositeMaterial

A0577:SeismicReliabilityAnalysis

ofEnergy-DissipationBridgeStructuresUsing

HamiltonianMonteCarloBasedSubsetSimulationinConjunctionwithExplicit

TimeDomainDimensionalityReduction

MichelPotier-Ferry Yang-BoLi NicholasOliveto Yu-lingLong Ti-RenHe Shao-MinJia

15:35--15:50

A0061:AModelingandResolutionFrameworkforWrinklinginHyperelasticSheetsat

FiniteStrain

A0283:Multiscale

ThermomechanicalAnalysisofReinforced

ConcreteBeamsSubjectedtoSuddenHeating

A0355:CollapsePerformance

AssessmentofSelf-CenteringPrecastConcreteWallswithDifferentPost-

TensioningandEnergyDissipationDesigns

A0753:APolynomialElement

BasedGalerkinApproachfortheSimulationof

MultivariateRandomFields

A0384:SeismicPerformanceofUnreinforcedMasonry

WallswithBoundaryRCFrame

Chen-BoFu HuiWang HaoWu Xu-FangZhang Young-ChanYou


Session



MaterialsChair(s): FanXu

MS1:CementitiousMaterials:

ExperimentsandModelingAcrosstheScales

Chair(s): Yi-MingZhang

MS7:Non-deterministic

modellinganduncertaintymanagementinstructural

dynamicsandvibroacoustics

Chair(s):MichaelBeer


andReliability-basedPerformanceEvaluationChair(s): Hong-ZheDai

MS6:Damagemodellingof

engineeringstructuresChair(s): LuHai

MS15:EnvironmentalEffectson

thePropertiesofCementitiousMaterials:

Experiments,ModelingandSimulation

Chair(s):TaoLi

16:10--16:25

A0089(Invited):Morphable3D

MesostructuresandMicroelectronicDevicesby

MultistableBucklingMechanics

A0139:StrengtheningEffectofCementitiousMaterials

SubjectedtoHigh-DynamicLoading

A0439(Invited):TheBhattacharyyaDistance:ANovel

UncertaintyQuantificationMetricinStochasticSensitivityAnalysis

A0944:ReliabilityAnalysisof

SeismicCapacityofShearWallConsideringPossible

TensionFailureandRandomEccentricity

A0169(Invited):ConcurrentFatigueCrack

GrowthandVehicle-BridgeDynamicsAnalysisUsing

Time-basedSybcycleFormulation

A0953(Invited):Multi-PhaseModellingof

Multi-speciesTransportinCementitiousMaterials:In

caseofElectrochemicalRehabilitation

EvaBinder Yan-BiaoWang

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16:25--16:40

A0089(Invited):Morphable3D

MesostructuresandMicroelectronicDevicesby

MultistableBucklingMechanics

A0198:MultiscaleModelingof

CementitiousMaterials:FromHydrationviaMicrostructureto

MacroscopicProperties

A0439(Invited):TheBhattacharyyaDistance:ANovel

UncertaintyQuantificationMetricinStochasticSensitivityAnalysis

A0558:ANovelMachineLearning-

BasedMethodtoPredictMemberBucklingfor

SquarePyramidSpaceGridStructure

A0169(Invited):ConcurrentFatigueCrack

GrowthandVehicle-BridgeDynamicsAnalysisUsing

Time-basedSybcycleFormulation

A0953(Invited):Multi-PhaseModellingof

Multi-speciesTransportinCementitiousMaterials:In

caseofElectrochemicalRehabilitation

Yi-HuiZhang BernhardPichler Si-FengBi QianZhang Yong-MingLiu Qing-FengLiu

16:40--16:55

A0433:ControllableRollingandConfigurableBendingin

FlexibleNanomemrbanes

A0244:Investigationofthe

Shrinkage-VolumetoSurfaceRatioRelationship

inCementConsideringCracking

A0044:StructuralReliabilityand

ReliabilitySensitivityAnalysisofExtremelyRare

FailureEventsbyCombiningSamplingandSurrogateModelMethods

A0540:EstimatingUncertaintyinLimitStateCapacitiesfor

ReinforcedConcreteFrameStructuresThroughPushoverAnalysis

A0879:ConstitutiveModelingof

DuctileandBrittleFailuresofSemicrystalline

Polymers

A0526:ExperimentalResearchonDynamicCharacteristicsofCrumbRubberConcreteat

LowTemperature

Yong-FengMei Yi-GeZhang Peng-FeiWei Xiao-HuiYu Jia-LiangLe GangXue

16:55--17:10

A0715:Electromechanical

Catastrophe

A0691:InsightintotheRoleofInterfacialBoltsontheStructuralBehaviorof

SegmentalTunnelRings

A0323:ModelingtheAsymmetricDependentSoilVariables

A0203:StochasticStayCableForceModelingUsingMonitoring

DatafromaCable-stayedBridge

A0477:MachineLearningbasedMultiscaleModelingof

BackwardErosionPiping

A0805:StochasticDynamical

BehaviorsofCorrosionReactionSystemin

ConcreteSubjectedtoExternalSulfateAttack

Tong-QingLu Jiao-LongZhang YiZhang MichaelHai-JunZhou AlessandroFascetti TaoLi

17:10--17:25

A0026:ActuatingSoftMaterialsinSurgeryRobotApplications

A0736:Meso-FiniteElement

FractureAnasysisforFiberReinforcedEmulsified

Asphalt-CementConcrete

A0079:Model-FormandParameterUncertaintyQuantification

inStructuralVibrationSimulationUsingFractional

Derivatives

A0389:PrestressedConcrete

BeamsFailingduetoWeb-Crushing:Uncertaintyand

ReliabilityAnalysis

A0827:ScalingEffectsforDynamic

ResponseswithApplicationtoBuriedArchesSubjectedto

InternalBlast

A0812:StochasticModelingof

SulfateIonDiffusionCoefficientattheConcrete-

SolutionInterface

BoLi JunFu Bao-QiangZhang OladimejiBenedictOlalusi SzeDaiPang Shan-ShanWang

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17:25--17:40

A0426:EdgeWrinklingofaSoft

RidgewithGradientThickness

A0028:Performanceofthe

ConcreteFreefromSteelReinforcement

A0535:ABayesianMethodfor

JointParameterOptimalEstimationbasedonPower

SpectralDensity

A0830:QuantifyingPost-disasterFunctionalityLossesandRecoveryofCommunity

BuildingPortfolios

A0451:SimulatingTime-

DependentQuasi-BrittleFailuresbasedona

MultilinearReleasingMechanismofViscous

ForceFields

A0966:ResearchonMoisture

TransportofCement-basedMaterialsBasedonLowFieldNuclearMagnetic

Resonance

YanZhao Jiang-TaoYu ZhangYong Nai-YuWang Jin-XingLiu XiaWu

17:40--17:55

A0483:LocalizedBulginginan

InflatedBilayerTube

A0651:AnalysisofSeismic

CollapseofHigh-RiseStructureunderNear-FaultPulse-TypeGroundMotion

YangLiu Tian-CanHuang

18:30--21:00 Banquet(The15thfloorofShanghaiJinjiangMetropoloHotel)

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Time Venue


8:30--9:50PlenaryLectures

Chair(s):Prof. GeorgeDeodatis

8:30--9:10

AnalysisofConcreteStructures

AJointResearchProjectofTongjiUniversityandViennaUniversityofTechnology

Prof.HerbertMang-ViennaUniversityofTechnology,Austria;TongjiUniversity,P.R.China

9:10--9:50UncertaintyPropagationfromMaterialsCharacterizationtoModeling

Prof.LoriGraham-Brady-JohnsHopkinsUniversity,USA


Sino-FrenchCenter





BulidingRoom1002TongjiUniversityZhonghe

BulidingRoom802

Session

MS18:ComputationalModelingof

AdvancedMaterialsandNovelStructuralSystems

forHazardMitigationChair(s): Mohamed

Moustafa




Chair(s): ZhengHeDi-XiongYang

MS7:Non-Deterministic

ModellingandUncertaintyManagementinStructural

DynamicsandVibroacoustics

Chair(s): Jian-BingChen



Chair(s): Da-GangLu

MS13:DamageandFailure

ModelingandAnalysisofConcreteandStructures

Chair(s): Zhao-DongDing

GS4:StructuralMechanicsand

SimulationChair(s): HaoZhou

10:10--10:25

A0368:SectionandFiniteElementAnalysisofSeismicUHPCPierswithHighStrength

Steel

A0112(Invited):RecentAdvancesin

EngineeringCharacteristicsofNear-FaultGroundMotionsandSeismic

EffectsofBuildingStructures

A0145(Invited):ARobustApproachto

QuantifyingForecastingUncertaintyUsingProxy

Simulations

A0518(Invited):GlobalDynamicSeismic

ReliabilityAnalysisforRCFrameStructuresUsingNT-

ANN

A0970(Invited):AnEquivalentStrainbasedMulti-ScaleDamageModel

ofConcrete

A0259:AParallelSpectralElementMethodfortheSimulation

ofScalarElasticWaves

MohamedMoustafa SeungwookYoun

10:25--10:40

A0363:Multi-PhysicsSimulationonPassivePatchAntennaSensorforWirelessStrain

Measurement

A0267:ANumercalStudyonthe

Thermo-MechanicalResponseofaComposite

BeamExposedtoFire

DanLi Di-XiongYang ScottCogan Da-GangLu Shi-XueLiang MoonSooKang

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10:40--10:55

A0729:PrimaryStructural

ConfigurationInvestigationofaNovelCouplingArmConnectingTwoFloating

Structures

A0313:FeaturesofOffshore

SeismicGroundMotionsDistinctfromtheOnshore

A0129:DynamicResponseofaTrain-BridgeIntractionSystemduetoSudden

DecelerationinHighSpeedRailwaySystems

A0020:RobustStatisticalMethods

forPowerSpectrumEstimationfromMultiple

SourceRecords

A0124:MultilevelModelingof

Fiber-ReinforcedConcreteandSimulationofCrackinginTunnelLiningSegments

A0310:TheoreticalStudyonVibrationofaSimply

SupportedFootbridgeunderDiscretePedestrian

Loading

TaoLi QiZhang Xu-ZhaoLu MarcoBehrendt Yi-JianZhan Shih-HsunYin

10:55--11:10

A0321:EnhancingSeismic

PerformanceofPorcelainElectricalEquipmentUsing

BaseIsolation

A0523:DynamicTestingofaFull-

ScaleFrp-RetrofittedReinforcedConcrete

BuildingFrame

A0414:Non-ProbabilisticModelofTransmissibilityFunctionsbasedonComplexInterval

Arithmetic

A0440:Identificationof

PerformanceDegradationModelbasedonStandard

WienerProcess

A0274:NumericalInvestigationof

ConcreteAgeEffectonShearLoadCapacityofPost-InstalledAnchors

A0721:Non-LinearNumerical

AnalysisonOverallProcessMechanicalBehaviorof

Quasi-RectangularSegmentalTunnelLining

WenBai JiukShin Meng-YunZhao XiaoWang RomanWan-Wendner ZhenLiu

Session


AdvancedMaterialsandNovelStructuralSystems

forHazardMitigationChair(s):Mohamed

Moustafa




Chair(s):ZhengHeDi-XiongYang

MS5:NonlinearStochasticStructuralDynamics

MethodologiesforComplexEngineeringSystems

Chair(s):Jian-BingChen



Chair(s):Da-GangLu


ModelingandAnalysisofConcreteandStructures

Chair(s):Zhao-DongDing


SimulationChair(s):HaoZhou

11:10--11:25

A0360:CharacterizationandModelingofAdaptive

RubberBearing

A0673:SeismicVulnerabilityof

RailwayNetworkbasedontheRunning-TrainsSafety

Evaluation

A0659:AnEfficientStochastic

ComplexModalAnalysisTechniquefor

NonclassicallyDampedandNonlinearMDOFStructural

Systems

A0423:StructuralFailurePattern

RecognitionandReliabilityAnalysisbasedonMulti-

ResponseSurfaceMethod

A0378:AnalyticalModelof

RockingElementswithDamagedCorners

A0467:ImpactLocationandLoadIdentificationUsingDeep

NeuralNetworks

Y.E.Ji ChengYang IoannisP.Mitseas ZhaoChen Hao-RanCui Jia-MingZhou

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11:25--11:40

A0671:SystemLevelAnalytical,

ExperimentalandHybridSimulationofResilient

HighwayBridges

A0899:Multi-ScaleComprehensive

SimulationofConcreteShearWallModels:

NumericalSimulation

A0802:AHybridSEM‒SMMethod

forSubwayRandomDynamicLoadsInducedbytheFrequency-DependentDynamicPropertiesofRail

Pads

A0580:ANewFractionalMoment

EquationsMethodforNonlinearVibration

Analysis

A0504:Developmentand

IdentificationofHysteresisModelforReinforced

ConcreteColumnsFailinginDifferentModes

A0983:AB-ScanSubsurface

ImagingofGroundCavitiesUsinganElasticWaveFull-

WaveformInversionMethod

SelimGunay Jing-RanHe KaiWei Rui-JingZhang Xin-LiangLyu BoyoungKim

11:40--11:55

A0008:PotentialRisksonUsingDisconnectedCompositeFoundationSystemsinActiveSeismicZones

A0890:StochasticResponse

AnalysisofanOffshoreWindTurbineunderthe

ExcitationsRepresentedbyStochasticHarmonic

Function

A0583:AKriging-Hdmr

MetamodelMethodforSystemReliabilityAnalysis

ofStructures

A0119:AFractureProblemwitha

SurfaceEnergyintheSteigmann-OgdenForm

MohamedElmasry Yu-PengSong Kai-XiangZhang AnnaZemlyanova

11:55--12:10

A0293:OptimalDesignofSMACableRestrainersfor

SeismicProtectionofaLRBIsolatedSimplySupported

HighwayBridge

ShuaiLi

12:20--13:30 Lunch(The3rdfloorofKingswellHotelBallRoom)


PlenaryLectureChair(s):Jian-YingWu

14:00--14:40MeshfreeMethods:ProgressMadeAfter20YearsandFutureDirections

Prof.Jiun-ShyanChen–UniversityofCalifornian,SanDiego,USA

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Sino-FrenchCenter





BulidingRoom1002TongjiUniversityZhonghe

BulidingRoom802

Session

GS3:WoodMechanics

Chair(s): Jan-WillemG.vandeKuilen

MS16:Fluid-Structure

InteractionsandFlow-InducedMotions

Chair(s):NingZhang

GS1:StochasticMechanicsand

StructuralReliabilityChair(s): Wang-JiYan


DamageandFailureinSolidsandStructures

Chair(s): Jian-YingWu


ModelingandAnalysisofConcreteandStructuresChair(s): Chao-LieNing


SimulationChair(s): Tian-CanHuang

14:50--15:05

A0968:VariablityinWood/PlantAnatomyAlongtheScales

A0159:Wind-InducedCladdingandStructuralLoadsonLow-RiseBuildingswith

4:12-SlopedHipRoofs

A0227:TowardsStochastic

ModelingofTsunamis

A0392(Invited):MitigatingMesh

DependenceofStochasticComputationof

QuasibrittleFracture

A0604:Three-DimensionalFinite

ElementModellingofUhpfrcJacket-Retrofitted

PiersunderCyclicLoading

A0512:UltimateCapacityofBulge

FormedT-JointsunderBraceAxialCompression

ExcludingtheChordLengthEffect

WolfgangGard ShuaiShao Zhi-HengWang TengTong Fei-LongNie

15:05--15:20

A0308:Developmentofan

AndvancedFE-NumericalMethodforStrengthPredictionofTimberBoardsbasedonthe

Surface

A0442:ApplicationsofImmersed

BoundaryMethodsinHydraulicModeling

A0554:AGenericFrameworkfor

ProbabilisticDamageCharacterisationUsing

UltrasonicGuidedWaveintheFrequencyDomain

A0635:SpatialCorrelationin

DisorderedHeterogeneousMaterials

A0595:Experimentaland

NumericalStudiesofResonanceVibrationofCablesinaFootbridge

ModelunderBiharmonicExcitation

AniKhaloianSarnaghi NingZhang Wang-JiYan Jia-LiangLe Zhao-DongDing WojciechPakos

Session

GS3:WoodMechanics

Chair(s):Jan-WillemG.vandeKuilen

MS16:Fluid-Structure

InteractionsandFlow-InducedMotions

Chair(s):NingZhang

GS1:StochasticMechanicsand

StructuralReliabilityChair(s):Wang-JiYan


DamageandFailureinSolidsandStructuresChair(s):Jian-YingWu

GS5:Bio-MechanicsandBone

MechanicsChair(s):Chao-LieNing


SimulationChair(s):Tian-CanHuang

15:20--15:35

A0955:DeformationKineticsfor

WoodMechanics

A0785:ModeInteractionsofDeep-

SeaRiserinShearFlow

A0454:Multidimensional

StochasticDamageModelforConcreteunderFatigue

Loading

A0757:CrackingElementsMethod

forSimulatingMultipleCracks

A0667:TheRelationBetweenCornealHydrationandStiffnessImprovementBecuaseoftheCornealCrosslinkingTreatment

A0903:Understanding

UncertaintiesfromCyclicTestsofShapeMemoryAlloyBarsforSeismic

Application

VandeKuilenJan-Willem Yuan-CenWang Yan-PengWang Yi-MingZhang HamedHatami-Marbini Jin-PengLi

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15:35--15:50

A0957:AnInvestigationofTheDolEffectofWood´inTension

PerpendicularooGrain

A0747:NonlinearParametric

VibrationAnalysisofRadialGates

A0751:AFractionalMomentMethodforReliabilityAnalysisofStructures

undertheSpatiallyVariability

A0633:PhaseFieldModelingof

HydraulicFracturingintheFrameworkoftheTheory

ofPorousMedia

A0870:A3-DimensionalModelling

ComparisonoftheBiomechanicalStabilityofLateralLumbarInterbodyFusionwithUnilateralorBilateralFixationMethod

A0164:HybridIntelligencefor

SolvingComplexEngineeringProblems:An

IntegratedHumanandMachineLearning

Approach

En-ChunZhu Si-YuanWu Xu-FangZhang Chen-YiLuo TengZhang Yong-MingLiu

15:50--16:05

A0960:AnInvestigationofFatigue

FractureofWoodduetoCyclicMoisture_Induced

Stress

A0972:Actively-Controlled

TurbulenceSimulationsandTheirEffectsontheAeroelasticPropertiesof

TypicalBridgeDeckSections

A0811:StochasticAnalysisofPolymerComposites

RupturesatLargeDeformationsModeledbya

PhaseFieldMethod

Qiong-YaoWu Yu-ChaoLv JieWu


Sino-FrenchCenter





BulidingRoom1002

Session

MS3:InstabilitiesandBifurcationsin

Solids,StructuresandSoftMaterials

Chair(s): MichelPotier-Ferry

MS12:DynamicAnalysisandSeismic

PerformanceofStructuresunderStrongEarthquakeGround

MotionsChair(s): Jing-QuanWang

JiukShin

MS17:StabilityandFailureofStructures

andMaterialsChair(s): Ji-FengXu

LimCheeWah

GS2:ComputationalMechanics

Chair(s): Jia-LiangLe

MS4:ComputerVision-basedStudiesinStructuralHealthMonitoring

Chair(s): MohammadJahanshahi

16:25--16:40

A0195:InteractionsBetweenTopologicalDefectNucleationandBoundary

BranchingintheGrowthofCurvedCrystals

A0016(Invited):Output-OnlyIdentificationof

CivilEngineeringSystems

A0925(Invited):Strengthening,FailureandTwinningMechanismsof

Graphene/CopperComposites

A0063:ModelReductionTechniquesforDynamicSystemswithaLarge

NumberofLocalModes

A0372:SystemIdentificationandSeismic

ResponseMonitoringofLarge-ScaleBridgeModelsUsing

Target-TrackingDigitalImageCorrelation

LongMa Xiao-ShuZeng MohamedMoustafa

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16:40--16:55

A0318:TheAmplitude-Frequency

ResponseofThinCompositePlateintheThermal

Environment

A0016(Invited):Output-OnlyIdentificationof

CivilEngineeringSystems

A0925(Invited):Strengthening,FailureandTwinningMechanismsof

Graphene/CopperComposites

A0102:Group-TheoreticExploitationsof

SymmetryinComputationalMechanicsofNovelPrestressed

Structures

A0387:AutomaticBoltLooseDetection

basedonDigitalImageProcessingTechnology

Jin-MingLi ErtugrulTaciroglu NingHu YaoChen Lin-ShengHuo

16:55--17:10

A0174:ModelingandSimulationofthe

Electro-MechanicalCouplingBehaviorofLiquidCrystal

Elastomers

A0883:DynamicTestingofaFull-Scale

FRP-RetrofittedReinforcedConcreteBuildingFrame

A0776:ClassificationofSteelH-ShapedCross-SectionsunderCombined

CompressionandBendingConsideringPlateInteraction

Effect

A0629:ImplementationofaMesh

Sensitive-LessApproachforthePseudo-LowerBoundMethod

A0910:AnAlgorithmforIdentificationof

StructuralParametersandExcitationForcesUsing

NoncontactVision-basedDisplacementMeasurements

Yi-WeiXu JiukShin Xue-SongHou MicheleDeFilippo YingLei

17:10--17:25

A0069:OntheWrinklingand

RestabilizationofHighlyStretchedRectangularSheets

A0530:SimplifiedModelbasedonSpectrumAnalysisforthe

OptimalOutriggerLocationofHigh-RiseBuildings

A0247:Hazard-IndependentStudyofthe

StabilitySensitivityoftheLowRiseFrameSystemsSubjectedtotheExtremeLoadingConditions

A0661:MechanicalPropertiesof

FilamentousNetworksinTermsofTheirMicrostructure

TingWang Li-LiXing ChristopherL.Mullen HamedHatami-Marbini

17:25--17:40

A0216:CurvatureEffectonWrinklingandRestabilizationofHighly

StretchedElasticShells

A0851:MultiscaleRandomFields-based

DamageModelingandAnalysisofConcreteStructures

A0875:BucklingofCompositePlateswithReinforcedOvalHoles

A0211:WeakEnforcementof

DisplacementConditionsinFictitiousDomainFiniteElement

Analysis

Yi-FanYang HaoZhou Ling-Weitang Kai-ZhouLu

17:40--17:55

A0990:TheoryandVerificationforCalculationofGirderBridge

OverturningwithCouplingofRigidandDeformableBody

Rotation

A0705:SoilArchingEffectBasedStudyontheStressDistributionandFailureModeoftheHolesforUnder-ExcavationinBuilding

Rectifying

A0031:ComputationApplicationDevelopmentinScientific

Paradigm

Wei-BingPeng Qing-XiaYue EchefuFrancisEmeka

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17:55--18:10

A0024:AnalysisoftheBridgewithSingle

ColumnbyPerformanceandReliability-basedSeismicDesign

Method

A0188:EffectofPowerTake-offDampingonHydrodynamicEfficiencyofan

OscillatingWaterColumnWaveEnergyDevice

Yi-QiangXiang PiyushMohapatra

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PlenaryLectures



25

ZdeněkP.Bažant

Born and educated in Prague (Ph.D. 1963), Bažant joined Northwestern in

1969, where he has been W.P. Murphy Professor since 1990 and

simultaneously McCormick Institute Professor since 2002, and Director of

CenterforGeomaterials(1981-87).HewasinductedtoNAS,NAE,Am.Acad.of

Arts&Sci.,RoyalSoc.London;totheacademiesofItaly(lincei),Austria,Spain,

CzechRep., IndiaandLombardy; toAcademiaEuropaea,Eur.Acad.ofSci.&

Arts. Honorary Member of: ASCE, ASME, ACI, RILEM; received 7 honorary

doctorates (Prague, Karlsruhe, Colorado, Milan, Lyon, Vienna, Ohio State);

AustrianCrossofHonorforScienceandArt1stClassfromPresidentofAustria;ASMEMedal,ASME

Timoshenko,NadaiandWarnerMedals;ASCEvonKarman,Freudenthal,Newmark,Biot,Mindlin

andCroesMedalsandLifetimeAchievementAward;SESPragerMedal;RILEML’HermiteMedal;

ExnerMedal(Austria);TorrojaMedal(Madrid);etc.Heauthoredeightbooks:ScalingofStructural

Strength, Inelastic Analysis, Fracture & Size Effect, Stability of Structures, Concrete at High

Temperatures, Concrete Creep and Probabilistic Quasibrittle Strength. H-index: 121, citations:

66,000(onGoogle, incl.self-cit.), i10 index:605. In2015,ASCEestablishedZPBažantMedal for

FailureandDamagePrevention.Heisoneoftheoriginaltop100ISIHighlyCitedScientistsinEngrg.

(www.ISIhighlycited.com).His1959mass-producedpatentofsafetyskibindingisexhibitedinNew

EnglandSkiMuseum.

Home:http://cee.northwestern.edu/people/bazant/

DesignofNewMaterialsandStructurestoMaximizeStrengthatProbabilityTail:A

NeglectedChallengeforQuasibrittleandBiomimeticMaterials

ZdeněkP.Bažant

NorthwesternUniversity,USA

Abstract: In developing new materials, the research objective has been to maximize the mean

strength (or fracture energy) of material or structure and minimize the coefficient of variation.

However, for engineering structures such as airframes, bridges of microelectronic devices, the

objective should be to maximize the tail probability strength, which is defined as the strength

correspondingto failureprobability10-6per lifetime.Optimizing thestrengthandcoefficientof

variationdoesnotguaranteeit.Theratioofthedistanceofthetailpointfromthemeanstrengthto

thestandarddeviationdependsonthearchitectureandmicrostructureofthematerial(governing

thesafetyfactor)iswhatshouldalsobeminimized.FortheGaussianandWeibulldistributionsof

strength, theonlyonesknownuptothe1980s, thisratiodiffersbyalmost2:1.For thestrength

distributions of quasibrittle materials, it can be anywhere in between, depending on material

architecture and structure size. These materials, characterized by a nonnegligible size of the

fractureprocesszone,includeconcretes,rocks,toughceramics,fibercomposites,stiffsoils,seaice,

snow slabs, rigid foams, bone, dental materials, many bio-materials and most materials on the

micrometerscale.Atheorytodeducethestrengthdistributiontailfromatomisticcrackjumpsand

Kramer’sruleoftransitionratetheory,anddetermineanalyticallythemultiscaletransitiontothe

representativevolumeelement(RVE)ofmaterial,isbrieflyreviewed.Thestrengthdistributionof

quasibrittleparticulateorfibrousmaterials,whosesizeisproportionaltothenumberofRVEs,is

obtainedfromtheweakest-linkchainwithafinitenumberoflinks,andischaracterizedbyaGauss-

Weibullgrafteddistribution.Closeagreementwiththeobservedstrengthhistogramsandsizeeffect



26

curves are demonstrated. Discussion then turns to new results on biomimetic imbricated (or

scattered) lamellarsystems,exemplifiedbynacre,whosemeanstrengthexceeds thestrengthof

constituentsbyanorderofmagnitude.Thenacreousquasibrittlematerialissimplifiedasafishnet

pulled diagonally, which is shown to be amenable to an analytical solution of the strength

probability distribution. The solution is verified by million Monte-Carlo simulations for each of

fishnetsofvariousshapesand sizes. Inaddition to the weakest-linkmodeland the fiber-bundle

model, the fishnet is shown to be the third strength probability model that is amenable to an

analyticalsolution. It is foundthat,aside fromitswell-knownbenefit for themeanstrength, the

nacreousmicrostructureprovidesasignificantadditionalstrengtheningatthestrengthprobability

tail.Finallyitisemphasizedthatthemostimportantconsequenceofthequasibrittleness,andalso

themosteffectivewayofcalibratingthetail,isthesizeeffectonmeanstructuralstrength.



27

HerbertMang

Born:January5,1942,Vienna,Austria;Dipl.-Ing.,CivilEngineering,and Dr.techn., Vienna University of Technology (VUT) (1967 and1970); University Assistant, VUT (1967-79); Fulbright Fellow(1971-72), Research Assistant (1973), Ph.D. (1974), all at TexasTech;MaxKadeFellow,CornellUniversity(1975-76);Habilitation,VUT (1977); Visiting Research Associate, University of Tokyo(1979);AssociateProfessor,VUT(1979-83);UNIDOFieldExpert,Zhengzhou Research Institute for Mechanical Engineering, China(1981);Prof.,HeadofInstituteforMechanicsofMaterialsandStructures,VUT(1983-2010);Prof.Emer.,VUT(10-2010-);NationalRPGEChairProf.,TongjiUniv.,Shanghai(2012-);Co-authorof8booksand4chaptersofhandbooks,co-editorof16books,author(co-author)of226journalpapersand 280 proceedings papers, book chapters, etc.; 12 International/Foreign Prizes (including 2Foreign Decorations) and 12 National Prizes (including 3 Young Investigator Awards and 4Decorations); 6 Honorary Doctorates (Technical University of Cracow, Innsbruck, Kiev, Leoben,Prague,andVilnius);1HonoraryProfessorship,TongjiUniversity,Shanghai;ForeignAssoc.ofCAEandNAE;Memberof3EuropeanAcademiesofSciences(andArts)andof15National/RegionalAcademies of Sciences/ Engineering (in Austria, Croatia, the Czech Republic, Georgia, Germany,Hungary, Poland (Warsaw and Cracow), Portugal, Slovakia, in the Ukraine, and in the USA);President, Austrian Academy of Sciences (2003-06); Vice-President, Austrian Science Council(2010-2015).

MultiscaleAnalysisofConcreteStructures

AJointResearchProjectofTongjiUniversityandViennaUniversityofTechnology

HerbertMangViennaUniversityofTechnology,Vienna

TongjiUniversity,P.R.China

Abstract: ThepapercontainsareportaboutajointresearchprojectofTongjiUniversityandViennaUniversityofTechnology.Itstitlereadsas“BridgingtheGapbyMeansofMultiscaleAnalysis”.Theprojectwasinspiredbythetunnel,bridgingthegapbetweenthetwopartsoftheHongkong-Zhuhai-MacaoBridge(HZMB),bridgingthegapbetweencitiesonoppositesidesofthemouthofthePearlRiver into the South Chinese Sea. The project stretches over the time period 2015-2019. It isfinanciallysupportedbytheAustrianScienceFundandtheChinaScholarshipCouncil.Theaimoftheprojectisanassessmentoftheaddedvalueofmultiscaleanalysisoftunnelsegmentsbymeansofacomparisonofresultswiththeonesfromexperimentaltestsandwithresultsfromconventionalstructuralanalysis.Thefollowingfourtopicswillbetreatedinthelecture:(1) microstructuralanalysisofimpactandblastloadingoftunnellinings(2) multiscaleanalysisofthermalstressesincementliningsduetosuddentemperaturechanges(3) experiments and finite element modeling of concrete in Mechanized Tunneling with special

emphasisonconcretehinges(4) experimentallysupportedmultiscalestructuralanalysisofasegmentaltunnelringTheprojecthas convincinglyprovedtheaddedvalueofmultiscalestructuralanalysis, underlinedtheimportanceofbothmaterialtestsandlarge-scalestructuralexperimentsand,

lastbutnotleast, enabled participation of highly qualified students from both Tongji University and Vienna

UniversityofTechnologyinchallengingresearchworkintheframeworkoftheirdoctoralthesis.Itisagoodexampleofameaningfulblendofmaterialmechanicsofconcreteandmultiscaleanalysisofconcretestructures.



28

Hai-YanHu

Prof.HaiyanHureceivedPh.D.inSolidMechanicsfromNanjingUniversityof

AeronauticsandAstronautics(NUAA),Chinain1988.Then,hewasaHumboldt

ResearcherFellowatUniversityofStuttgart,GermanyandaVisitingProfessor

atDukeUniversity,USAsuccessively.HereceivedProfessorshipinMechanics

in NUAA in 1994, served as President of NUAA from 2001 to 2007, and

PresidentofBeijingInstituteofTechnologyfrom2007to2017.

Prof. Hu has made recognized contributions to the nonlinear dynamics and

controlofaerospacestructures,includingthedelayedcontrolofflexiblestructures,thenonlinear

vibration isolation of missile stabilizers, the active flutter suppression of aircraft wings, and the

deploymentdynamicsofspaceantennas.HewaselectedFellowofTheChineseAcademyofSciences

in2007,FellowofTheWorldAcademyofSciences(TWAS)in2010,andawardedHonoraryDoctor

ofSciencebyMoscowStateUniversity,Russiain2015andbyUniversityofReading,UKin2016,

respectively.

EngineeringDynamicsofSoftMachines

HaiyanHu

BeijingInstituteofTechnology,P.R.China

Abstract:Theconceptofsoftmachinescoversagreatvarietyofadvancedindustrialproducts,such

asasoftrobothandlingfragileobjects,adeployablesolarsailandanairplanewithmorphingwings.

Thosesoftmachinesaremainlycomposedofsoftbodies,whicharemadeofsoftmaterials,including

polyimide,siliconelastomerandelectro-activepolymer,soastoadapttocomplexenvironmentsor

missions. Furthermore, the soft bodies undergo not only large deformations, but also overall

motionsandfrictionalcontactswiththemselvesortheirenvironments.

This lecture presents the dynamic study on soft machines in the frame of multibody system

dynamics.Thestudyfocusesontheefficientdynamicmodelingofthegeometricalnonlinearityof

coupledoverallmotionand largedeformationofasoftbody, thephysicalnonlinearityofhyper-

elasticity and elasto-plasticity, and interactional nonlinearity of frictional contacts or even

entanglementsofsoftbodies,aswellastheefficientdynamiccomputationalgorithmofrigid-soft

multibodysystemgovernedbyasetofdifferential-algebraicequationsofveryhighdimensions.The

lecture illustrates the proposed approach via three case studies, i.e., the locomotion of a soft

quadrupedalrobot,thespinningdeploymentofasolarsailofspacecraft,andthedeploymentofa

meshreflectorofsatelliteantenna,aswellasthecorrespondingexperimentalstudies.



29

Jiun-Shyan(JS)Chen

J. S. Chen is currently the Inaugural William Prager Chair Professor of

Structural Engineering Department and the Director of Center for Extreme

EventsResearchatUCSanDiego.BeforejoiningUCSDinOctober2013,hewas

the Chancellor’s Professor of UCLA Civil & Environmental Engineering

DepartmentwhereheservedastheDepartmentChairduring2007-2012.J.S.

Chen’s research is in computational mechanics and multiscale materials

modelingwithspecializationinthedevelopmentofmeshfreemethods.Heis

thePastPresidentofUSAssociationforComputationalMechanics(USACM)andthePastPresentof

ASCE Engineering Mechanics Institute (EMI). He has received numerous awards, including the

Computational Mechanics Award from International Association for Computational Mechanics

(IACM), ICACE Award from International Chinese Association for Computational Mechanics

(ICACM),theTedBelytschkoAppliedMechanicsAwardfromASMEAppliedMechanicsDivision,the

BelytschkoMedal,U.S.AssociationforComputationalMechanics(USACM),amongothers.Heisthe

FellowofUSACM,IACM,ASME,EMI,ICACM,andICCEES.

MeshfreeMethods:ProgressMadeAfter20YearsandFutureDirections

Jiun-Shyan(JS)Chen

UniversityofCalifornian,SanDiego,USA

Abstract: In the past two decades, meshfree methods have emerged into a new class of

computationalmethodswithconsiderablesuccess.Inaddition,asignificantamountofprogresshas

beenmadeinaddressingthemajorshortcomingsthatwerepresentinthesemethodsattheearly

stages of their development. For instance, essential boundary conditions are almost trivial to

enforcebyemployingthetechniquesnowavailable,andtheneedforhighorderquadraturehas

been circumvented with the development of advanced techniques, essentially eliminating the

previouslyexistingbottleneckofcomputationalexpense inmeshfreemethods.Given theproper

treatment,nodalintegrationcanbemadeaccurateandfreeofspatialinstability,makingitpossible

to eliminate the need for a mesh entirely. Meshfree collocation methods have also undergone

significantdevelopment,whichalsoofferatrulymeshfreesolution.Thispresentationwillgivean

overviewofmajorprogressesmadeinthefield,theapplicationtomanychallengingengineering

mechanicsproblems,andthefuturedirectionsofthisresearcharea.



30

Jin-GuangTENG

ProfessorJin-GuangTengisaVice-PresidentofSouthernUniversityofScience

andTechnology(SUSTech)andaChairProfessoratbothSUSTechandTheHong

KongPolytechnicUniversity(fractionalappointment).HeisanAcademicianof

the Chinese Academy of Sciences, a Fellow of the Hong Kong Academy of

Engineering Sciences and a Corresponding Fellow of the Royal Society of

Edinburgh.

Professor Teng has conducted research on a wide range of topics across the

broadfieldofstructuralengineering,includingthestructuraluseoffibre-reinforcedpolymer(FRP)

composites in construction as well as steel and thin-walled structures. He has authored/co-

authoredover200SCIjournalpapers,leadingtoover9,500citationsandanH-indexof50according

totheWebofScienceCoreCollection.Manyofhisresearchfindingshavebeenadoptedbyrelevant

designcodes/guidelinesinChina,Australia,Europe,theUnitedKingdomandtheUnitedStates.His

research contributions have been recognized by many awards and prizes, including the State

Natural Science Award of China, Distinguished Young Scholar Award from the National Natural

ScienceFoundationofChina,theIIFCMedalfromtheInternationalInstituteforFRPinConstruction

(IIFC), and the State-of-the-Art of Civil Engineering Award from the American Society of Civil

Engineers.

MechanicsofinterfacesinFRP-strengthenedstructures

Jin-GuangTENG

SouthernUniversityofScienceandTechnology,China

Abstract: The performance of structures, particularly concrete structures, can be substantially

enhanced through the external bonding of fiber-reinforced polymer (FRP) reinforcement in the

form of thin laminates. In such an FRP-strengthened structure, the interface between the FRP

laminateandtheexistingstructureplaysakeyroleindeterminingitsbehaviorandstrength.Indeed,

extensivelaboratorytestinghasdemonstratedthatfailureofFRP-strengthenedstructuralmembers

oftenoccursbydebondingoftheFRPlaminatefromtheexistingstructuralmemberinanumberof

distinctmodes.Inthispresentation,thespeakerwillprovideabriefreviewoftheintensiveresearch

undertakenoverthepasttwodecadesonthesedebondingfailureproblemsandasummaryofthe

currentunderstandingofinterfacialmechanicsinFRP-strengthenedstructuralmembersthathas

resultedfromthisresearch.Themajorpartofthepresentationwillbeconcernedwithinterfacesin

FRP-strengthenedconcretemembers,butinterfacesinFRP-strengthenedsteelmemberswillalso

be given due attention. The specific aspects to be covered include: (1) fundamental behavior of

bondedinterfaces;(2)classificationofdebondingfailuremodes;(3)debondingfailuremechanisms

and processes; (4) finite element and theoretical modelling issues; (5) design methods. The

presentationwillendwithabriefdiscussionoffutureresearchneeds.



31

LoriGraham-Brady

Lori Graham-Brady is Professor and Chair of the Civil Engineering

Department at Johns Hopkins University, with secondary

appointments in Mechanical Engineering and Materials Science &

Engineering.SheisalsotheAssociateDirectoroftheHopkinsExtreme

Materials Institute. Her research interests are in computational

stochasticmechanics,multiscalemodelingofmaterialswithrandom

microstructureandthemechanicsoffailureunderhigh-rateloading.

ShehasbeenheavilyinvolvedinEMI,asamemberoftheEMIBoardofGovernors,asanAssociate

EditorfortheJournalofEngineeringMechanics,andastheChairoftheEMIProbabilisticMethods

Committee.Shehasreceivedanumberofawards,includingthePresidentialEarlyCareerAwardfor

ScientistsandEngineers(PECASE),theWalterL.HuberCivilEngineeringResearchPrize,andthe

WilliamH.HugginsAwardforExcellenceinTeaching.

Uncertaintypropagationfrommaterialscharacterizationtomodeling

LoriGraham-Brady

JohnsHopkinsUniversity,USA

Abstract: Three-dimensional microstructures collected by experimental characterization provide

both statistical information and the basis for computational models, which allows us to analyze

heterogeneousmaterialsatsmalllengthscales.However,thecollectionofsuchthree-dimensional

microstructuraldatacommonlyreliesondestructivetechniques,suchasserialsectioning,andsuch

methods often provide no quantitative measure of the accuracy of the digital microstructure in

representingthetruephysicalspecimen.Thismakesqualityassessmentofthedatasetsdifficult

and it poses a challenge to identify which characterization parameters will produce optimal

efficiency in the data collection process while maintaining an acceptable level of error in the

resultingdata.Toaddressthisquestion,thispresentationdescribesacomputationalmethodthat

wasdevelopedtosimulateserialsectioningdatacollection,basedonadigitalrepresentationofa

material,calledaphantom.Bysimulatingthedatacollectionanddataprocessingprotocolsofuser

definedparameterssuchasresolution,slicethickness,dwelltime,polishingmethod,etc.theeffect

ofeachonerrorpropagationcanbetrackedrelativetothefullyunderstooddigitalphantom.Then

byvaryingeachparametertheeffectscanbestudiedindividuallyandprovideboundsonboththe

contributions of each parameter to the error as well as the total error introduced through the

experimental process. This provides a quantitative method for comparing the relative trade off

betweenexperimentalparameterssuchcollectingdataataveryhighresolutionvs.collectingdata

overalargevolume.Ultimatelythesemeasuresarethenutilizedaspartofanobjectivefunctionto

optimize the selection of experimental parameters. An example of optimization of experimental

datacollectionparametersfortheacquisitionofan3DElectronBackscatterDiffraction(EBSD)data

setdemonstrateshowtheerrorincomputationalmodelscanbereduced.



32

Abstracts



33

MS1: Cementitious Materials: Experiments and

Modeling across the Scales

A0013- Road guard innovative use of plastic waste material in redesigning road

curbs

AhiatiEbenezera

aStudent,KwameNkrumahUniversityofScienceandTechnology,

[email protected]

TherearemanydeterioratedroadsinGhana,WestAfrica.Thesedeteriorationsmostlyoccur

duetoerosionfromrainfallandcauseseveraldepressionsinroads,mostlyalongtheedges.

Thiscanhaveadverseeffects,suchasaccidents.Analternativetoprotectingroadedgesafter

construction is the use curbs. However, traditional curbs are expensive and using them as

means of protection for a road system is not feasible. Hence, this paper introduces a cost

effective and reliable approach of using a polymer-based product molded into grids, Road

Guard, since reconstruction of roads after a short while of usage is too expensive for a

developingcountry.TheRoadGuardwillbeproducedfromrecyclingplasticwaste,whichis

anothermajorprobleminthecountry,andwillbeconvertedintogridsthroughmeltingand

casting.Itwillhaveanarbitrarylengthof20.669feet(6.3meters)withachannelatabout

every19.029feet(5.8meters)toallowforrainwaterrun-offs.Installationwillbecarriedout

byplacingtheroadguardat theedgesof theroadandfilling itwiththeroadconstruction

material (concrete, bitumen, etc.) before, during or after road construction. After a cost

analysis it was obtained that equivalent length of Road Guard compared to the curbs was

cheaper.Apartfromsolvingtheissuewiththeroads,theplasticwastemenaceinthecountry

willalsobeaddressedsincetheywillbeusedtoproducethedevice.Inconcluding,theRoad

Guardisstill intheconceptualstagesandhenceneedsalotoftesting.However,onemajor

setbackisthelackoffundingtoproduceaworkingmodeleventhoughaprototypehasbeen

producedfromcardboardforsubsequentinstallationtests.



34

A0028-Performanceoftheconcretefreefromsteelreinforcement

YUJiangtaoa,YeJunhongb,ZHANKailic

aCollegeofCivilEngineering,TongjiUniversity,ShanghaiChina,email:

[email protected]

bCollegeofCivilEngineering,TongjiUniversity,ShanghaiChina

cCollegeofCivilEngineering,TongjiUniversity,ShanghaiChina

Ultra-high ductility cementitious composites (UHDCC) developed by the authors has the

tensilestraincapacityclosetothatofsteel.ToexplorethefeasibilityofusingplainUHDCCin

construction, a series of experiments were conducted at material, structural member and

structure scales, including mechanical properties of UHDCC, the behavior of plain UHDCC

beams and columns under monotonic and lateral cyclic loadings, and the responses of

compositeUHDCCframeundervariousearthquakeexcitations.Thetestresultsindicatedthat

the average tensile strain capacity of UHDCCs reached 12%, exceeding the strain capacity

required forsteelusedtoreinforceconcretestructure.Additionally,UHDCCevenexhibited

strain-hardeningcharacteristicsundercompression.Theresultsfromfour-pointbendingtest

demonstratedtheoutstandingperformanceofUHDCCbeamsunderlateralcyclicloading.The

plainUHDCCbeamhascloseloadbearingcapacitytothereferenceRCbeamswiththesteel

reinforcementratioof1.0%butmuchbetterflexuralductility.RCframe(reinforcementratios

ofcolumnswereabout2.0%)andplainUHDCCframewerecomparativelytestedonashaking

table.TheplainUHDCCframesurvivedaseriesofseismicexcitationswiththepeakground

accelerationrangingfrom0.105gto1.178g,andexhibitedbetterenergy-dissipatingcapacity

associated with consistently increasing damping ratio under earthquake excitations. The

performanceoftheplainUHDCCframefulfilledtherequirementsinChineseseismiccode,i.e.,

no damage under the frequently occurring earthquake, being repairable under the design-

based earthquake, and no collapse under the rarely occurring earthquake. Generally, this

seriesstudyfrommaterialscaletostructurescaleconfirmedthefeasibilityofconstruction

withplainUHDCC.



35

A0038- Macro-scale strength and microstructure of ZrW2O8 cementitious

compositeswithtunablelowthermalexpansion

OuyangJianshua,YangboLib,BoChenc,DahaiHuangd

aSchoolofTransportationScienceandEngineering,BeihangUniversity,Beijing,China

bCollegeofHydraulicandEnvironmentalEngineering,ChinaThreeGorgesUniversity,

YichangHubei,China,email:[email protected]

cCollegeofHydraulicandEnvironmentalEngineering,ChinaThreeGorgesUniversity,

YichangHubei,China

dSchoolofTransportationScienceandEngineering,BeihangUniversity,Beijing,China

Concretes with engineered thermal expansion coefficients, capable of avoiding failure or

irreversible destruction of structures or devices, are important for civil engineering

applications, such as dams, bridges and buildings. In natural materials, thermal expansion

usuallycannotbeeasilyregulatedandanextremelylowthermalexpansioncoefficient(TEC)

is still uncommon. Here we propose a novel cementitious composite, doped with ZrW2O8,

showingawiderangeoftunablethermalexpansioncoefficientfrom8.65×10-6℃-1to2.48×10-

6℃-1. Macro-scale experiments are implemented to quantify the evolution of the thermal

expansioncoefficients,compressiveandflexuralstrengthoverawiderangeoftemperature.

Scanning Electron Microscope(SEM) imaging was conducted to quantify the specimens’

microstructuralcharacteristicsincludingporesratioandsize.ItisshownthattheTECofthe

proposed composites depends on the proportion of ZrW2O8 and the ambient curing

temperature.Macro-scaleexperimentalresultsandmicrostructureshaveagoodagreement.

TheTECandstrengthgraduallydecreaseasZrW2O8increasesfrom0%to20%,subsequently

fluctuatesuntil60%.Thefindingsreportedhereprovideanewroutinetodesigncementitious

compositeswithtunablethermalexpansionforawiderangeofengineeringapplications.



36

A0139-Strengtheningeffectofcementitiousmaterialssubjectedtohigh-dynamic

loading

E.Bindera,Y.Yuanb,H.Mangc,B.Pichlerd

aPhDcandidate,InstituteforMechanicsofMaterialsandStructures,TUWien–Vienna

UniversityofTechnology,Austria,Europe,[email protected]

bProfessor,CollegeofCivilEngineering,TongjiUniversity,Shanghai,People’sRepublicof

China,[email protected]

cProfessor,InstituteforMechanicsofMaterialsandStructures,TUWien–ViennaUniversity

ofTechnologyAustria,Europe,andCollegeofCivilEngineering,TongjiUniversity,Shanghai,

People’sRepublicofChina,[email protected]

dProfessor,InstituteforMechanicsofMaterialsandStructures,TUWien–ViennaUniversity

ofTechnology,Austria,Europe,[email protected]

The compressive strength of concrete increases with increasing speed of dynamic loading.

Fischeretal.developedanelasto-brittlemodeltoaccountforthisstrengtheningeffect.The

mainideaofthismodelisthatcracksnucleateassoonasthequasistaticstrengthisreached

andthathigh-dynamicstrengtheningmanifestsitselfintheincreaseofthecompressivestress

duringtheevolutionofthefailuremode.Fischeretal.corroboratedthepredictivecapabilities

ofthemodelbycomparingmodelpredictionswithexperimentaldatafromhigh-dynamictests

ofspecificcementpasteandmortarspecimens.Continuedexemplaryvalidationisthetopicof

the first part of this contribution. Model predictions are compared with additional

experimentaldatafromhigh-dynamictestsofspecificmortarandconcretecylinders.Inthe

secondpart,themodelofFischeretal.iscombinedwiththevalidatedmultiscalemodelfor

thequasi-staticcompressivestrengthofconcretebyKönigsbergeretal.,tostudytheinfluence

ofhardeningoftheconcreteusedfortheimmersedtunneloftheHongKong-Zhuhai-Macao-

Bridgeonitsdynamiccompressivestrength.Inthethirdpart,themodelisextendedtowards

considerationofthehigh-dynamictensilestrength.



37

A0198- Multiscale modeling of cementitious materials: from hydration via

microstructuretomacroscopicproperties

BernhardPichlera,ChristianHellmichb

aAssociateProfessorandDirectoroftheLaboratoryforMacroscopicMaterialTesting,

InstituteforMechanicsofMaterialsandStructures,TUWien–ViennaUniversityof

Technology,Austria,Europe,[email protected]

bFullProfessorandDirectoroftheInstituteforMechanicsofMaterialsandStructures,TU

Wien–ViennaUniversityofTechnology,Austria,Europe,[email protected]

The philosophy of multiscale modeling of heterogeneous materials is to resolve their

microstructure,inastep-by-stepfashion,downtoascaleatwhichmaterialconstituentsare

foundthatexhibitmaterialconstantsratherthanevolvingmaterialparameters.Concrete,for

instance,isamatrix-inclusioncomposite,withaggregatesandsandrepresentinginclusions

which are embedded in a cement paste matrix. The properties of cement paste are not

constant,becausetheydependon itscompositionandmaturity, i.e.onthe initialwater-to-

cementmassratioandthedegreeofhydration.Thus,cementpasteismodeledasamatrix-

inclusion composite, with residual cement particles representing inclusions which are

embeddedinahydratefoammatrix.Thehydratefoamisahighlyrandomizedarrangementof

capillary pores (which are filled either by water or air) and hydration products which are

needle-shaped and isotropically-oriented in space. As for the hydration products, material

constantscanbeintroduced,whichallowforpredictionofthehydration-drivenevolutionsof

stiffness,creep,andstrengthofcementitiousmaterials.Thepresentcontributionprovidesan

overviewoverrelatedmultiscalemodelingactivitiescarriedoutattheInstituteforMechanics

of Materials and Structures at TU Wien – Vienna University of Technology. Concretes are

considered to consist of aggregates, sand, cement, water, air, and hydration products. The

latterarethe“glue”ofthemicrostructure,theonlycreepingconstituent,andtheweakestlinks

ofthemicrostructureofcementitiousmaterials.Thus,theyareessentialforthemacroscopic

stiffness, creep, and strength of cementitious materials. Eshelby-problem-based

homogenization schemes of continuum micromechanics allow for bridging all the scales

between the hydration products and the macroscopic application scale of cementitious

materials. It can be shown that the behavior of hydration products is governed by simple

physical laws. The latter translate, because of microstructural interactions with other

constituents,intoacomplexmacroscopicbehaviorofcementitiousmaterials.



38

A0244- Investigation of the shrinkage - volume to surface ratio relationship in

cementconsideringcracking

Y.Zhanga,M.H.Hublerb

aResearchAssistant,UniversityofColorado,Boulder,[email protected]

bAssistantProfessor,UniversityofColorado,Boulder,[email protected]

Standardized shrinkage models for concrete incorporate a function which depends on the

volumetosamplesurfaceratio(V/S).This functionstemsfromexperimentalobservations

andhasbeenrationalizedbasedonnon-uniformporehumiditydistributionsduringdrying,

whichdependonV/S.Suchshrinkagestressdistributionsshouldalsoleadtodifferentcrack

developmentasafunctionofV/S.Byconductingcompanion3DX-rayMicroscope(XRM)scans

andshrinkagestudiesofcementsofdifferentV/Sratios,theimpactofcrackdevelopmenton

thissizeeffectrelationshipisstudied.TheXRMscanscanresolvedryingcontourstovalidate

computed pore humidity distributions. Furthermore, the scanned internal surface area

(incorporatingporesandcracks)providesamoreaccuraterepresentationofdryingsurface.

Byintegratingtheinternalsurfaceareaintothecomputedporehumditydistributions, it is

possible to understand how cracking and porosity play a role in the shrinkage to V/S

relationship.



39

A0278-DynamicpropertyidentificationofshakingtabletestaboutexistingR.C

CHENGShaogea,SUNKuib

aResearcher,ChinaAcademyofBuildingResearch,Instituteofearthquakeengineering,

[email protected]

bDoctoralstudent,ChinaAcademyofBuildingResearch,Instituteofearthquakeengineering,

[email protected]

Becauselowconnectionstrengthandhighstiffnessbetweeninfilledmasonrywallandframe,

the infilled would separate from major structure members or cracked in less earthquake

influence, then the dynamic properties of specimen had changed significantly. So that the

whitenoiseusedforspecimenhadasmallamplitude,andashortduration.Largedeviations

existedinfrequencydomainmethodathighfrequencies,indicatinglessaccuracyoffrequency

domainmethod.Systemidentificationofthespecimenwereextractedfromflooraccelerations

underthewhitenoiseexcitationsbytheeigensystemrealizationalgorithmmethodandnature

excitationtechnique .Dampingcharacteristicsof thespecimenwere identified. It isshown

that eigensystem realization algorithm method is effective and sensitive to higher modes

respectively. And it can identify the crack behavior of infilled masonry wall. High mode

vibrationiseasytooccurforexistingR.C.frame.



40

A0283- Multiscale thermomechanical analysis of reinforced concrete beams

subjectedtosuddenheating

H.Wanga,Y.Yuanb,H.Mangc,B.Pichlerd

aInstituteforMechanicsofMaterialsandStructures,TUWien–ViennaUniversityof


bCollegeofCivilEngineering,TongjiUniversity,Shanghai,People’sRepublicofChina,

[email protected]

cInstituteforMechanicsofMaterialsandStructures,TUWien–ViennaUniversityof


dInstituteforMechanicsofMaterialsandStructures,TUWien–ViennaUniversityof


Steel-reinforcedconcretestructuresaresubjectedtosuddentemperaturechanges,e.g.,inthe

exceptional load case of a fire. At the macrostructural scale, kinematic constraints are

hinderingthedeformationsassociatedwiththethermaleigenstrains.Thus,thermalstresses

areinduced.Theconstraintsoriginatefromthreesources:thesupportconditionsofstatically

indeterminatestructures,thegeometricincompatibilityofmacroscopiceigenstrainsresulting

fromnon-stationaryheatconduction,andthemismatchofthermalexpansioncoefficientsof

the steel and the concrete. At the microstructural scale of plain concrete, self-equilibrated

stresses prevail even in the absence of macroscopic kinematic constraints. These stresses

resultfromthemismatchofthethermalexpansioncoefficientsofthecementpasteandthe

aggregates.Thepresentcontributionisinspiredbyapotentialfireinsidetheimmersedtunnel

oftheHongKong-Zuhai-Macao-Bridge.Theoverheadslabsofthesegmentsofthetunnelare

idealizedasreinforcedconcretebeams.Theirbottomsurfacesaresubjectedtosuddenheating.

Three-dimensionalanalysesprovideinsightintomacroscopicandmicroscopicstressstates.

Tothisend,modernmultiscalematerialmodelsforconcreteareusedtoquantifytheelastic

stiffnessandthethermalexpansioncoefficientoftheconcreteusedforthesegmentsofthe

aforementioned immersed tunnel. These macroscopic properties serve as input for

thermomechanical Finite Element simulations of the steel-reinforced concrete beams. The

obtained macroscopic temperature distributions and stress fields are postprocessed in the

contextoftop-downanalysiswhichallowsforquantifyingthemicroscopicaveragestresses

experienced by the cement paste and the aggregates. Two sources of microscopic stress

fluctuations are identified: macro-to-micro stress concentration, governed by stiffness

contrasts,andtheincompatibilityofthemicroscopicfieldsofthermaleigenstrains,governed

bythemismatchofthethermalexpansioncoefficientsofthecementpasteandtheaggregates.



41

A0327- Influenceofsteel fibre,electricalwastecopper fibreandE-glass fibreon

mechanicalpropertiesofconcrete

A.Sofia,G.GaneshNaidub

aAssociateProfessor,DepartmentofStructuralandGeotechnicalEngineering,SchoolofCivil

Engineering,VITVellore,Tamilnadu,India,[email protected]

bResearchScholar,SchoolofCivilEngineering,VIT,Vellore,Tamilnadu,India

Fibre-reinforced concrete (FRC) contains fibrous material which increases its structural

integrity. The application of sporadic fibres to concrete altogether upgrades its essential

characteristics,forinstance,staticflexuralstrength,influencequality,elasticity,malleability

andflexuralstiffness.Filamentsareaddedtocementtocontrolbreakingbecauseofplastic

shrinkageandtodryingshrinkage.Thispaperexhibitstheuseofsteelfibre,electricalwaste

copperfibreandE-glassfibreofvariouspercentagesofvolumefractionssuchas0.25%,0.5%,

1%and1.25%incorporatedinconcrete.Mechanicalpropertiessuchascompressivestrength,

splittensilestrengthandflexuralstrengthtestswereconductedfornormalconcreteandfibre

reinforcedconcreteforacuringperiodof7days,14daysand28days. Inadditiontothat

modulusofelasticityofconcreteforvariouspercentagesoffibrecontentwascalculatedfora

curingperiodof28days.Thetestresultsof fibrereinforcedconcretewerecomparedwith

normalconcretetoobtaintheoptimumdosageoffibresused.



42

A0685- Effects of loading rates and temperatures on pullout responses of basalt

yarnandfabricembeddedincementitiousmatrix

SaiLiua,DejuZhub

aKeyLaboratoryforGreen&AdvancedCivilEngineeringMaterialsandApplication

TechnologyofHunanProvince,CollegeofCivilEngineering,HunanUniversity,Changsha,

China

bKeyLaboratoryforGreen&AdvancedCivilEngineeringMaterialsandApplication

TechnologyofHunanProvince,CollegeofCivilEngineering,HunanUniversity,Changsha,


Pullout response of basalt fabric embedded in cementitious matrix specimens was

investigatedunderdifferentloadingratesandtemperatures.Twotypesofpulloutspecimens,

namelybasaltsingleyarnandbasaltfabricweretested.Thepulloutbehaviorsofspecimens

wereevaluatedintermsofinitialpulloutforce,peakpulloutforce,workofpulloutandwork

ofpeakforce(Fig.1).Pulloutvelocityrangesfromstatic(5.0×10-5m/s)todynamic(1.0,2.0,

3.0and4.0m/s);Anddynamicresponseswerestudiedunderfourtemperatures(-25,0,25,

50̊ C)withdifferentloadingrates.Theexperimentalresultsindicatedthatthepulloutvelocity,

temperatureandthefabricformcansignificantlyaffectthepulloutresponses.Thereexista

typicalthreestagesduringpulloutloadings(Fig.1).Ateachtemperature,theinitialandpeak

pulloutforcesunderdynamicloadingarehigherthanthestaticones.Inaddition,thepullout

workandpeakpulloutworkappeartobeimprovedwithincreasingloadingrateundereach

temperature.Ontheotherhand,whenthepulloutvelocityisconstant,theinitialpulloutforce,

peak pullout force, work of pullout and work of peak force decreased with increasing

temperatures. While the pullout work and peak pullout work appear to be improved with

increasingpulloutvelocitiesundereachtemperature.

Fig.1.Schematicof(a)threestagesofthepulloutprocessand(b)definedparametersto

characterizethepulloutresponsesunderloading.



43

A0691- Insight into the role of interfacial bolts on the structural behavior of

segmentaltunnelrings

J-L.Zhanga,H.A.Mangb,X.Liuc,Y.Yuand,B.Pichlere

aPhDstudent,DepartmentofGeotechnicalEngineering,TongjiUniversity,PRChina

[email protected]

bProf.,DepartmentofGeotechnicalEngineering,TongjiUniversity,PRChina

[email protected]

cProf.,DepartmentofGeotechnicalEngineering,TongjiUniversity,PRChina

[email protected]

dProf.,DepartmentofGeotechnicalEngineering,TongjiUniversity,PRChina

[email protected]

eProf.,InstituteforMechanicsofMaterialsandStructures,TUWien–ViennaUniversityof


Steelboltsarefrequentlyusedtoconnectneighboringsegmentsofsegmentaltunnelrings.

Oncetheboltsbecomeactiveintension,theyincreasethelocalbendingstiffnessandthelocal

bearingcapacityofthejoint.Inordertogainmoreinsightintotheroleofinterfacialboltson

theoverallstructuralbehaviorofsegmentaltunnelrings,structuralsensitivityanalysesoftwo

similartunnelrings,onewithunreinforced jointsandtheotheronewithbolted joints,are

carried out. They involve combining nonlinear interface models with transfer relations

representinganalyticalsolutionsofthegoverningequationsofthe lineartheoryofslender

circulararches.Thesensitivityanalysesrefertodeterminationoftheelasticlimitandofthe

bearingcapacityof the segmental tunnel ringssubjected togroundpressure.Theanalyses

haveshownthatinterfacialbolts(i)decreasetheelasticlimitintensityofgroundpressure,(ii)

improve the serviceability of segmental tunnel rings, because they ensure the position

stabilityofthelining,(iii)aremandatoryforoverallstructuralequilibriumincaseofmarkedly

anisotropicgroundpressure,and(iv)significantlyincreasethebearingcapacityofsegmental

tunnelrings. Inordertoverifytheseconclusions,real-scaletestsofthreetunnelrings,one

withoutinterfacialbolts,onewithnewbolts,andonewithcorrodedbolts,werecarriedout.

The experimental investigations have confirmed the conclusions listed above. This

corroboratestheusefulnessofthepresentedmodelforstructuralanalysisofsegmentaltunnel

ringsandprovidesthemotivationtoemployitforfuturestructuralanalysisaccountingfor

durabilityofinterfacialbolts.



44

A0736-Meso-finiteelementfractureanasysisforfiberreinforcedemulsifiedasphalt

–cementconcrete

JunFua,TaoZhangb,ZhehanLaic

aAssociateProfessor,WuhanUniversityofTechnology,[email protected]

bMasterCandidate,WuhanUniversityofTechnology,[email protected]

cMasterCandidate,WuhanUniversityofTechnology,[email protected]

PVAfiberswasusedto improvethe flexural tensilestrengthandcrackresistance forFiber

Reinforced Emulsified Asphalt–Cement Concrete(FREACC). Three-point bending test and

uniaxialcompressiontestshowedthatPVAfibercouldsignificantlyimprovethemacroscopic

flexuraltensilestrengthandfractureenergyofthemixture,whichhadanincreasemorethan

100%and50%,buthadlittleeffectonthecompressivestrengthandelasticmodulus,which

hadanincreaseabout3%.Inmesoscale,FREACCcouldbeconsideredasthreephaseswhich

wereaggregates,fiber-asphaltcementmortar,andpores.Basedonthetwo-dimensionalimage

digitizationandbilinearcohesivezoneconstitutiverelation,themeso-finiteelementfracture

modelcouldbeestablishedbyinsertingtwo-dimensionalzero-thicknesscohesive interface

elementsintotheinterfacebetweendifferentphases.Uniaxialtensilefractureanddynamic

crackingofthree-pointbendingbeamweresimulated,thentheeffectofPVAfibersonfracture

toughness was discussed. The numerical simulation value of fracture energy was slightly

larger thantheexperimentalvalue,andthemeso-fractureanalysiswas ingoodagreement

withthemacroscopictestresults.Theresultsofmicrofractureanalysisalsodepictedthatthe

interfacebetweenaggregateandasphaltmortarwasaweakphase,wherethefracturestarted

fromtheinterface.AndPVAfibercouldeffectivelyenhancethetensilestrengthofthemixture

anddelaythecrackpropagation.Thecriticalfractureloadandthecorrespondingmid-span

displacement of meso-numerical simulation were slightly smaller than the experimental

values,butthedifferenceoftensilestrengthwasnotobvious.Thenumericalsimulationvalue

of fracture energy was slightly larger than the experimental value, but the meso-fracture

analysiswasingoodagreementwiththemacroscopictestresults,demonstratingthatthetwo-

dimensionalmeso-fracturemodelwasrelativelyaccurateunderuniaxialloadingandthree-

pointbendingconditions.



45

A0761- Time-space dependent stability analysis of shallow natm tunnels with

discontinuitylayoutoptimization

Yiming.Zhanga,Xiaoying.Zhuangb,c,Roman.Lacknerd

aSchoolofCivilandTransportationEngineering,HebeiUniversityofTechnology,Tianjin,


bDepartmentofGeotechnicalEngineering,TongjiUniversity,Shanghai,China,

[email protected]

cInstituteofContinuumMechanics,LeibnizUniversitätHannover,Hannover,Germany

dMaterial‐TechnologyInnsbruck(MTI),UniversityofInnsbruck,Innsbruck,6020,Austria,

[email protected]

Shallow tunnels constructed by New Austrian Tunnelling Method potentially experience

stability problems caused by inappropriate excavation speed or supporting procedures.

Stabilityofthesectionsofthesetunnelsaretime-spacedependent,referringtothehydration

processesofshotcrete,shapesofthetunnelsandexcavationspeed.

Inthiswork,weimplementthemultiscalemodelofhydratingshotcreteintotheframeworkof

discontinuitylayoutoptimization,whichiscapableofefficientlyobtainingthefactorofsafety

and the corresponding failure mechanism of tunnel section. Meanwhile, convergence-

confinementmethodisusedforaccountingthe3-dimensionaleffectin2-dimensionalanalysis,

providingtime-spacedependentstabilityassessmentsofthesetunnels.



46

A0887-MechanicalperformanceofGFRPsandwichpanelswithstiffenwebs

FangMing-Jia,HouHetaob,WangWenhaoc

aSchoolofCivilEngineering,ShanghaiNormalUniversity,Shanghai,P.R.China

bSchoolofCivilEngineering,ShandongUniversity,Jinan,P.R.China

cSchoolofCivilEngineering,ShandongUniversity,Jinan,P.R.China

Thispaperpresentsthedetailsofaresearchprogramthatwasconductedtoevaluatetheone-

waybendingbehaviorofglassfiberreinforcedpolymer(GFRP)sandwichpanels.Thepanels

consistofGFRPskinswithafoam-GFRPwebcore.Anexperimentalstudywerecarriedoutto

studytheeffectoftheskinandwebthickness,thewebheightandthewebspace.Theresults

demonstrate that compared to the only foam-core sandwich panels, a maximum of

approximately230%increaseintheultimatebendingstrengthcanbeachieved.Meanwhile,

thebendingstiffnessandenergydissipationcanbeenhancedrespectively.Acomparisonof

theexperimentalandanalyticalresultsshowedthattheanalyticalmodelaccuratelypredicted

the ultimate bending strengths deflections of the panels under four-point bending.

Furthermore, the finite element analysis was conducted to simulate the bending behavior

consideringthebondperformanceofthefacesheetsandfoamcore.



47

A0919-Microstructuralcharacterizationofthespuncastconcrete

M.Sobótkaa,M.Pachniczb,J.Michałekc

aassistantprofessor,FacultyofCivilEngineering,WrocławUniversityofScienceand

Technology,[email protected]

bPhDstudent,FacultyofCivilEngineering,WrocławUniversityofScienceandTechnology,

[email protected]

cassistantprofessor,FacultyofCivilEngineering,WrocławUniversityofScienceand


Theaimoftheworkwastopreparetheprocedurefordeterminingselectedmicrostructure

propertiesofthespunconcretewithparticularemphasisonthevariationoftheseproperties

withthedistanceRfromtheouteredgeofthemember.Theresearchwascarriedoutusing

threedifferenttestingmethods:nanoindentation,X-raymicrocomputedtomography(mCT)

and 2D optical scanning. Obtained results allowed to characterize quantitatively following

features of concrete internal microstructure: the distribution of aggregate throughout the

member cross-section, the variability of mechanical parameters of the mortar with the

distanceRandthespatialdistributionofthepores.

TheanalysisofaggregatedistributiononthecoordinateRwasbasedontheresultsofoptical

scanning.Surfacepreparationof theconcretesamples forscanning includedgrinding,acid

etchingandmatrixdyeing.Aggregatesegmentationfromtheimageswasmadeusingdigital

imageprocessingtechniques.Morphometricanalysisincluded,amongothers,determination

ofthevolumefractionandlocalthicknessoftheaggregate.

Inordertodeterminethemechanicalparametersofthemortar(cementmatrixtogetherwith

fineaggregate), thenanoindentationmethodwasutilized.Aseriesof testswascarriedout

withCSM(AntonPaar)TTX-NHTapparatusequippedwithBerkovichtip.Severalmeasuring

gridsweresetwithinthemortaratarbitrarylocationscorrespondingtodifferentvaluesofR

distance. Each of the grids included 100 imprints spaced at 50 μm. The results of the

performedtestsallowedtoestimateaveragevaluesofthehardnessHITandtheindentation

modulusMIT.Furthermore,applyingdeconvolutionmethodallowedtoestimatethefraction

of the fine aggregate in mortar φ and to calculate the average hardness and average

indentationmodulusforthecementitiousmatrixandtheaggregateseparately.



48

Theanalysisoftheporesdistributionthroughouttheconcretevolumewasbasedonthe3D

imagingbymCT.BrukerSkyscan1172scannerwasutilizedtoacquireasetofprojections.

ImagereconstructionwasperformedusingBrukerNReconsoftwarebasedontheFeldkamp

algorithm.SincethegrayscalevaluesinmCTdependmostlyonthematerialdensityonecan

assess the variation of average material density with the coordinate R. To characterize the

spatialarrangementofthepores,theywerefirstsegmentedbythresholding.Next,thebinary

imagesoftheporeswasanalyzed.Theporespacewaspresentedinathree-dimensionalmodel

andquantitativeanalysiswasperformed.



49

MS2: Modeling Time-Dependent Behavior and

Deterioration of Concrete

A0042-Concretecreepmodeling:applicationtoslabsonground

YaWeia,SimingLiangb,JingsongHuangc

aM.ASEC,AssociateProfessor,DepartmentofCivilEngineering,TsinghuaUniversity,Beijing,


bPost-doc,DepartmentofCivilEngineering,TsinghuaUniversity,Beijing,China,

[email protected]

cMasterstudent,DepartmentofCivilEngineering,TsinghuaUniversity,Beijing,China,

[email protected]

Moisturewarpingofconcreteslaboccursasa longprocessdueto theslowtransportation

natureofmoisture inconcretematerials.And thuscreep,asa timedependentpropertyof

concrete,willinevitablyaffecttheperformanceofslabongroundduringthisprocess.Inthis

study, the effect of concrete creep is considered in pavement slab for analyzing moisture

warping, warping stress, and the total stress under traffic loads. A method is proposed to

calculatethetime-dependentwarpingdeformationandstressdevelopmentsinconcreteslab

onground.Thismethodusesthesequentialcoupledhygromechanicalfiniteelementanalysis

andincorporatesconcretecreepmodelwhichiscapableofconsideringtherelativehumidity

effect.Theeffectofenvironmentrelativehumidity,thedesignparameters,includingconcrete

type,slabsize,thickness,boundingconditionwiththebase,andtheageofconcreteexposed

todryingare investigatedontheslabwarpingandstressconsideringthecreepeffect. It is

found that concrete creep has a significant effect on slab warping and stresses. It is of

importancetoconsidercreepeffectindesignandanalyzingdeformationandstressgenerated

inconcretepavementslabs,particularlywhenamoisturegradientexistsinslab.



50

A0082-NumericalmoduledevelopmentfortheentireprocessofRCdeterioration

duetonon-uniformcorrosion

This study presents a mathematical model to depict each sub-process of reinforcement

corrosion and their coupling effect based on the physical mechanisms of corrosion

electrochemical reaction. Then, a physical-chemical-electro-chemical-mechanical multi-

physicscoupledcomprehensivenumericalmoduleisdevelopedtosimulatetheentireprocess

ofthecorrosion-induceddeteriorationofRCstructure;andthereductionoftheload-carrying

capacityoftheRCstructureversusexposuretimecanbegivendirectly.Thedistributionof

corrosionproductsonthesurfaceofthesteelreinforcementwillbedeterminedautomatically,

withouthavingtobepresetinadvance.Topredicttheexpansionpressureofconcreteandthe

evolution of cracking pattern caused by non-uniform corrosion, a new smeared rust layer

method is first proposed here. Several sets of experimental data were compared with the

predictionbythenumericalmodelforitsverification.



51

A0093-Concreteshearwallsaffectedbyalkali-silicareactionpartii:modeling

AncaC.Ferchea,ShamimA.Sheikhb,FrankJ.Vecchioc

aPhDCandidate,UniversityofToronto,[email protected]

bProfessor,UniversityofToronto,[email protected]

cProfessor,UniversityofToronto,[email protected]

Aprocedurefornonlinearanalysisofreinforcedconcretestructuresaffectedbyalkali-silica

reaction(ASR) is presented.Twodistinct time-dependentmechanismsareconsidered: the

magnitude of the expansion, and the deterioration in the mechanical properties of the

concrete. With these mechanisms implemented within the framework of finite-element

programs developed for the analysis of membrane and three-dimensional structures, a

smearedrotating-crackmacro-modelingapproachwasappliedtotheanalysisofASR-affected

shear walls tested under reversed-cyclic loading. The modeling techniques employed are

detailed, as well as the factors affecting the computed response of the specimens. The

sensitivitystudiescarriedout identifyseveralmechanismsthathadanotableeffectonthe

behavior.Basedontheresultspresentedherein,themodelingproceduresdescribedarefound

tobeusefulforthecapacityassessmentofdeterioratedshearwallsduetoASR.



52

A0098-Concreteshearwallsaffectedbyalkali-silicareactionparti:testing

FarhadHabibia,FrankJ.Vecchiob,ShamimA.Sheikhc

aPhDCandidate,UniversityofToronto,[email protected]

bProfessor,UniversityofToronto

bProfessor,UniversityofToronto,[email protected]

ReactiveaggregateshavebeenusedinnuclearpowerplantstructuresinNorthAmericaand

elsewhere. Nuclear structures, in general, are heavily reinforced and often prestressed.

AlthoughASRhasbeenextensivelystudiedovertheyears,availableinformationontheeffects

ofASRonsuchstructuresislimited.

Theexperimentalstructuralpartofthisresearchprogramisfocusedontestingofreinforced

concrete walls made with ASR concrete and evaluating their performance against similar

controlwallsthatexcludereactiveaggregates.Atotalofsixwallswereconstructed,fourmade

with ASR concrete and two with normal concrete. All the walls and accompanying small

specimens such as cylinders and prisms were conditioned in a specially-constructed high

temperature and high humidity chamber to accelerate the reaction and deterioration. This

paper will present results from these walls that were tested in three phases under lateral

displacementexcursionswhilesimultaneouslysubjectedtoaxialloadthussimulatingseismic

loads.Inthefirstphase,afterabout6monthsofconditioning,theASRwallwasfoundtohave

about14%highercapacitythannormalwallalthoughtheASRconcretestrengthandstiffness

valuesweremuchlowerthanthoseofnormalconcrete.Inthefinalphaseaftertheexhaustion

ofASRreaction,theASRshearwallshowedsignificantlylessductilebehaviourcomparedto

the normal wall and similar ASR walls tested in low damage phase. Ductility and ultimate

lateraldisplacementofthewallswereconsiderablyreducedasASRexpansionprogressed.



53

A0117- Modeling corrosion of reinforcement in concrete: accelerated vs. Natural

corrosion

JoškoOžbolta,b,GojkoBalabanićb

aUniversityofStuttgart,InstituteofConstructionMaterials,Pfaffenwaldring4,Stuttgart,

Germany,[email protected]

bUniversityofRijeka,FacultyofCivilEngineering,RadmileMatejčić3,Rijeka,Croatia,

[email protected]

Chloride-inducedcorrosionofsteelreinforcementinconcreteisoneofthemajorcausesfor

deteriorationofreinforcedconcretestructures.Therefore,topredictdurabilityofRCstructure

itisimportanttohaveanumericaltool,whichisabletopredictcorrosionprocessesandtheir

consequences for the structural safety. The main problem in formulating such models is

quantifying controlling parameters for processes before and after depassivation of

reinforcement.

Thefirstobjectiveofthepresentcontributionistovalidatetherecentlydeveloped3Dchemo-

hygro-thermo-mechanicalmodelforconcretebymeansofanextensiveexperimentalprogram,

whichincludestestsundernaturalandlaboratorycontrolledconditions.Particularattention

is paid in characterizing the parameters of the hysteretic moisture model as well as the

concreteconductivity.

Theexperimentsrelatedtothecorrosionofsteelreinforcementinconcreteareusuallycarried

out under accelerated conditions. The results of such experiments are then used in the

formulationofdesignformulas.However,therecanbealargedifferencebetweenaccelerated

andnaturalcorrosion.Forinstance,thecorrosionproductsaresignificantlydifferent,i.e.the

expansionfactorofcorrosionproductsincaseofacceleratedcorrosionismuchsmallerthan

inthecaseofnaturalcorrosion.Moreover,distributionofcorrosionoverthereinforcement

surface for the same geometry can be different. To illustrated these differences numerical

studyforthebeam-endspecimenwithstirrupsisperformedforbothcases.Thespecimenis

firstexposedtoacceleratedandnaturalcorrosion.Subsequently,themainreinforcementbar

is pulled-out out from the specimen to investigate the influence of the corrosion induced

damageonthepull-outcapacity.Toverifythemodel,theresultsofacceleratedcorrosionare

alsocomparedwiththeavailableexperimentalresults.Itisclearlydemonstratedthatthere

aresignificantdifferencesbetweentheresultsobtainedforacceleratedandnaturalcorrosion.

Especially the position and variation of corrosion rate over the main reinforcement and

stirrupsareratherdifferent.Therefore,theexperimentalresultsobtainedunderaccelerated

corrosionconditionsshouldbeusedinthepracticewithspecialattention.



54

A0287-Agedependentshearresistanceofreinforcedandprestressedconcrete

LinWan-Wendnera,RomanWan-Wendnerb

aPostdoctoralResearchFellow,PolitecnicodiMilano,[email protected]

bDirector,ChristianDopplerLaboratory,BOKU,Vienna,[email protected]

Conventionalfiniteelementsoftwareandassociatednumericalmodelsaretypicallyusedto

analyzethemechanicalbehaviorofstructuralscaleconcretebeams.However,theylackthe

ability toaccount for theheterogeneityofconcreteoraginganddeteriorationeffects.This

paper introduces a comprehensive computational framework to model the behavior of

reinforcedandprestressedconcretebeamsundershear load.The frameworkconsists ofa

discrete particle model incorporating effects from concrete aging, creep, shrinkage and

prestressloss.Five-meterlongconcretebeamswithfullreinforcementanddifferentprestress

levelsweretestedundershearloads.Materialtestsoftheconcreteonvariousages,including

unconfinedcompression,uniaxialteststomeasuremodulusofelasticity,splittingtests,and

fracture tests were carried out. Concrete creep and shrinkage measurements were also

conductedtostudytheireffectonprestresslossandconsequentlytheshearresponse.The

modelconstructsthebeamwithconcreteasdiscreteparticlesandthesteelrebars/tendons

as beam elements. The concrete behavior is defined by constitutive laws with its material

propertiescalibratedbasedonstandardexperimentaltests.Thebehaviorofreinforcedrebars

and prestressing tendons follow the elasto-plastic law of typical steel with known Young’s

modulusandyieldingstrength.Therebarbeamelementsandsolidconcreteelementsinteract

with each other using penalty constraints. Before the shear load is applied, creep and

shrinkagelossesofconcreteareevaluated,ofwhichtheparameterswerecalibratedbasedon

the experimental measurements. The results of the predictive shear simulations for the

reinforcedandprestressedbeamsresemblethoseofthetestedspecimensincludingbutnot

limitedtotheforce-displacementresponses,thefailuretypes,andthecrackpatterns.Withthe

well-calibrated and validated aging framework, the shear resistance of the prestressed

concretememberscanbeaccuratelypredicted.



55

A0593-Probabilisticmodeloftheyieldingstrengthforthecorrodedrebars

X.Gaoa,Y.Panb

aAssociateProf.,TongjiUniversity,[email protected]

bMasterstudent,TongjiUniversity,[email protected]

Corrosionoftherebar isthemajortriggerofthecrackofthecover, thedegradationofthe

bondperformanceandthebearingcapacityoftherebar.Therefore,thebearingcapacitywill

bedecreasedandeventhefailuremodeoftheRCmembersmaychangefromtheductilefailure

to the brittle failure. The degradation of the bearing capacity and the time-dependent

reliabilityofreinforcedconcretememberscanbepredictedaccuratelyonlyifthevarietyof

theyieldingstrengthofthecorrodedrebarhasbeenacquired.Inthispaper,1706testdata

collectedfrom31referenceswereclassifiedintothreegroupsaccordingtothecauseofthe

corrosionwhichwereconstantcurrentacceleratedcorrosion(CCAC),acceleratedcorrosion

test in simulated environment(ACTSE) and in-suit corrosion of the practical RC

members(ISCA).Basedontheexistingresearch,theyieldingstrengthoftheunstainablepart

of the corroded rebar is the same as the normal rebar. Accordingly, the minimum cross-

sectionalareaofthecorrodedrebaratthedifferentcorrosionrateisthekeyissuetoobtain

thebearingcapacityofthecorrodedrebar.

ByusingLillieforstest,theabnormaldataweredeleted.Theprobabilitydistributionmodelof

the minimum normalized section area k of corroded steel bars of the three cases follows

normaldistribution.Accordingtotheanalyzedresults,itisfoundthatthechangeofthemean

valueofkISCAisminimalwiththeincreaseofthecorrosionrate,whilethemeanvalueofkACTSE

decreasedthemost.Thereby,whenCCACandACTSEmethodsareadopted tosimulate the

corrosionoftherebar,thenormalizedminimumsectionareakshouldberevisedbythefactors

presentedinthepaper.Meanwhile,thedistributionofthemeanvalueofkISCAismorescattered

whenthecorrosionrateincrease.Thepresentedprobabilisticmodeloftheyieldingstrength

forthecorrodedbarswasverifiedbyusingtheconfidenceintervalof50%and95%.Whenthe

confidenceintervalis50percent,morethanhalfofthedatawasintheconfidenceinterval.

Almostallofthedataisintheconfidenceintervalwhentheconfidenceintervalis95percent.

ItisprovedthattheprobabilitydistributionmodelofkISCAproposedinthispaperisaccurate

andreliable,andhasgoodapplicability.Moreover,thebearingcapacityofaRCbeamswere

calculatedduetothedifferentcorrosionrateofthe longitudinalbarsandthestirrups.It is

proved that the failure mode of the RC beams can change from the flexural failure to the

shearingfailure.



56

A0708-AtheoreticalframeworkforcreepeffectanalysisofaxialloadedshortCFST

columnsunderhighstresslevels

ShiweiLia,YongqingYangb

aDr.,SouthwestJiaotongUniversity,[email protected]

bProf.,SouthwestJiaotongUniversity,[email protected]

Duetoitsexcellentmechanicalperformances,axialloadedconcrete-filledsteelcirculartube

(CFST)columnshavebeenwidelyusedinstructuralengineering.Asanimportantlong-term

behaviorofCFSTstructures,creephasanobviousnonlinearpropertyunderhighthestress

levels,i.e.,creepisnotlinearlydependentonthestresses,whichmakestheinfluenceofcreep

more complicated. In this study, to analyze the impacts of nonlinear creep effect on the

behaviorofaxial loadedshortcfstcolumns,acompletetheoretical frameworkforcoupling

analysis of 3D creep effect and material nonlinearity was presented. First, to simulate the

plasticity and damage evolution of concrete core under high stress levels, a new concrete

plasticitydamagemodelwithuniformconstraint(UCCDP)wasestablished.Next,basedonthe

UCCDPandcreepPossionratio,a3Dnonlinearcreepanalysismethodandthecorresponding

numerical analysis method were established, which was implemented into the ABAQUS

secondaryplatform.Finally,bycomparingthepredictedresultswithexperimentalresultsin

different stress levels, this approach for predicting the creep of axial loaded short CFST

columnshasexhibitedsatisfactoryaccuracy.



57

MS3: Instabilities and Bifurcations in Solids, Structures

and Soft Materials

A0026-Actuatingsoftmaterialsinsurgeryrobotapplications

BoLia,DichenLib,ShuxinWangc,HualingChend,GuiminChene

aAssociateProfessor,Xi’anJiaotongUniversity,[email protected]

bProfessor,Xi’anJiaotongUniversity,[email protected]

cProfessor,TinjinUniversity,[email protected]

dProfessor,Xi’anJiaotongUniversity,[email protected]

eProfessor,Xi’anJiaotongUniversity,[email protected]

Conventional surgical robot are in straight-bar shape and made of rigid materials mostly,

which fail to adapt to the minimally invasive surgical operation using natural orifices.

Therefore,wedevelopaflexiblesurgicalrobotbasedonsoftmaterials.Multi-DOFdeformation

andvariablestiffnessabilitiesviaelectro-pneumaticactuationandfiberjammingtechniques,

ispresented.Theintegratedmanufacturingprocessofthemanipulatorunitisdeveloped.An

experimentaltestsystemissetuptoobtainthenonlinearrelationshipsbetweenthebending

deformation,outputforceofthepneumaticartificialmuscleactuatorandtheairpressure,by

eliminatingtheinstability.Therelationshipsbetweenanti-bendingabilityofasingleunitand

negative pressure, fiber arrangement and fiber density are further studied. The optimized

designschemeisobtained.Withinacomplexsystem,themulti-DOFdeformationinbypass,

thetrackingandthestiffnesstunabilityofthemanipulatoraredemonstrated.



58

A0054-Patterntransitionsinasoftcylindricalshell

FanXua,YifanYangb,Hui-HuiDaic,MichelPotier-Ferryd

aInstituteofMechanicsandComputationalEngineering,DepartmentofAeronauticsand

Astronanutics,FudanUniversity,Shanghai,P.R.China,[email protected]

bInstituteofMechanicsandComputationalEngineering,DepartmentofAeronauticsand

Astronanutics,FudanUniversity,Shanghai,P.R.China,[email protected]

cDepartmentofMathematics,CityUniversityofHongKong,HongKong,P.R.China,

[email protected]

dUniversitédeLorraine,CNRS,ArtsetMétiersParisTech,LEM3,F-57000Metz,France,

[email protected]

Instabilitypatternsofrollingupasleeveappearmoreintricatethantheonesofwalkingover

a rug on floor, both characterized as systems of uniaxially compressed soft film on stiff

substrate.Thiscanbeexplainedbycurvatureeffects.Toinvestigatepatterntransitionsona

curvedsurface,westudyasoftshellslidingonarigidcylinderbyexperiments,computations

and theoretical analyses. We reveal a novel postbuckling phenomenon involving multiple

successivebifurcations:smooth-wrinkle-ridge-saggingtransitions.Theshellinitiallybuckles

intoperiodicaxisymmetricwrinklesatthethresholdandthenawrinkle-to-ridgetransition

occursuponfurtheraxialcompression.Whentheloadincreasestothethirdbifurcation,the

amplitudeoftheridgereachesitslimitandthesymmetryisbrokenwiththeridgesagginginto

a recumbent fold. It is identified that hysteresis loops and the Maxwell equal-energy

conditions are associated with the coexistence of wrinkle-ridge or ridge-sagging patterns.

Such a bifurcation scenario is inherently general and independent of material constitutive

models.



59

A0061-Amodelingandresolutionframeworkforwrinklinginhyperelasticsheets

atfinitestrain

C.FUa,T.Wangb,F.Xuc,Y.Huod,M.Potier-Ferrye


Astronautics,FudanUniversity,220HandanRoad,Shanghai,P.R.China,[email protected],

[email protected]



[email protected]

cInstituteofMechanicsandComputationalEngineering,DepartmentofAeronauticsand


[email protected]

dInstituteofMechanicsandComputationalEngineering,DepartmentofAeronauticsand


[email protected]

eUniversitédeLorraine,CNRS,ArtsetMétiersParisTech,LEM3,F-57000Metz,France,

[email protected]

Wrinklesarecommonlyobservedinuniaxiallystretchedrectangularhyperelasticmembranes

with clamped-clamped boundaries, and can disappear upon excess stretching. Here we

developamodelingandresolutionframeworktosolvethiscomplexinstabilityproblemwith

highlygeometricandmaterialnonlinearity.Themainadvantagesofthisframeworkinclude

thegeneralityforbothcompressibleandincompressiblematerials,easeofprogramming,high

precision and efficient continuation predictor. Moreover, various compressible or

incompressiblemodelscanbesystematicallyderivedbasedon3Dstrainenergypotentials,

e.g.,Saint-VenantKirchhoff,neo-Hookean,Mooney-Rivlin,GentmodelandGent-Gentmodel.

Basedontheproposedapproach,effectofdifferentincompressibleconstitutivemodelsonthe

post-buckling response is quantitatively investigated, which shows limited influence on

bifurcationdiagrams.However,forcompressiblematerials,Poisson’sratioplaysacriticalrole

inthewrinklingandrestabilizationbehavior.WefindthatsmallerPoisson’sratiomakeslater

onsetofwrinkling, loweramplitudeandearlierdisappearanceofwrinkles.Besides,severe

strain-stiffeningphenomenaareexploredbyaccountingforphenomenologicalmodelssuch

asGentmodelandGent-Gentmodel.Efficiencyandaccuracyofthemethodwereexaminedby

comparingwithexperimental,numericalandanalyticalbenchmarks.



60

A0069-Onthewrinkingandrestabilizationofhighlystretchedrectangularsheets

T.Wanga,C.Fub,F.Xuc,Y.Huod,M.Potier-Ferrye


Astronautics,FudanUniversity,Shanghai,P.R.China,[email protected],

[email protected]



[email protected]



[email protected]



[email protected]

eUniversitédeLorraine,CNRS,ArtsetMétiersParisTech,LEM3,F-57000Metz,France,

[email protected]

Wrinkles are commonly observed in uniaxially stretched rectangular sheets with clamped-

clampedboundaries,andcandisappearuponexcessstrtching.Hereweexplorethiswrinkling

andrestabilizationbehaviorbothanalyticallyandnumerically.Effectofdifferentconstitutive

models, i.e., Saint-Venant Kirchhoff, neo-Hookean and Mooney-Rivlin, on the post-buckling

responseareinvestigated,whichshowsratherlimitedquantitativeinfluenceonbifurcation

diagrams. Poisson’s ratio, however, plays a crucial role in the wrinkling and restabilization

behavior.WefindthatsmallerPoisson’sratiomakeslateronsetofwrinkling,loweramplitude

andearlierdisappearanceofwrinkles.Inparticular,whenPoisson’sratioisbelowathreshold,

nowrinklesoccur,whichcanbeexplainedbythedecreasingtransversecompressivestresses

withrespecttothereducingPoisson’sratio.Futhermore,basedontheKoiterbucklingtheory,

wehavesemi-analyticallypredictedsecondarybifurcationpointsforthefirsttime,through

looking into the sign change of the quadratic terms in potential energy. Both theoretical

bucklingandsecondarybifurcationpointsareingoodagreementwithfiniteelementresults.



61

A0089-Morphable3Dmesostructuresandmicroelectronicdevicesbymultistable

bucklingmechanics

YihuiZhanga

aDepartmentofEngineeringMechanics,TsinghuaUniversity,Beijing,P.R.China

Three-dimensional(3D)structurescapableofreversibletransformationsintheirgeometrical

layouts have important applications across a broad range of areas. Most morphable 3D

systems rely on concepts inspired by origami/kirigami or techniques of 3D printing with

responsivematerials,sometimesreferredtoas4Dprinting.Thedevelopmentofschemesthat

can simultaneously apply across a wide range of size scales and with classes of advanced

materialsfoundinstate-of-the-artmicrosystemtechnologiesremainsagrandchallenge.This

talkintroducesasetofconceptsformorphable3Dmesostructuresindiversematerials(e.g.,

device-grade silicon, metals and polymers) and fully formed planar devices, including

integratedelectronicsystemswithhighperformancecapabilities,spanninglengthscalesfrom

micrometers to millimeters. The approaches rely on elastomer platforms deformed in

differenttimesequencestoelasticallyalter,withengineeringcontrol, the3Dgeometriesof

supported mesostructures via controlled processes of non-linear mechanical buckling.

Comprehensivestudiesofmulti-stabilityandcorrespondingenergylandscapesinthiscontext

establish general design strategies. Demonstrations include experimental and theoretical

investigationsofover20examples,includingmesostructuresthatcanbereshapedbetween

differentgeneralizedandrecognizablegeometriesaswellasthosethatcanmorphintothree

ormoredistinctstates.Twofunctionallyreconfigurablemicroelectronicdevices,includingan

adaptiveradiofrequencycircuitandaconcealableelectromagneticdevice,provideexamples

oftheseconcepts.



62

A0121-Wrinklingofsoftbiomaterials

BoLia

aAssociateProfessor,TsinghuaUniversity,[email protected]

Biological materials often exhibit diverse morphologies, which can arise from either

physiologicalorpathologicalgrowth.Inthisstudy,wecombinetheoreticalanalysis,numerical

simulations,andexperimentalobservationtoelucidatehowthesemorphologiesaredriven

anddictated.Takingbiofilmsandmucosaeas twotypicalexamples,weshowthatresidual

stressesresultingfromdifferentialgrowthofbiologicalmaterialsareabletotriggersurface

wrinkling,whichleadstovariouspatterns.Phasediagramsareestablishedtodemonstratethe

rolesofthickness,elasticmoduli,andinterfacebondinginregulatingthesewrinklingpatterns.

Itisfoundthatgeometricalcurvatureandinterfacialdelaminationcanfurtherenrichsurface

wrinkling.Ourstudyhighlightstheroleofmechanicsinsculptingbiologicalmorphogenesis.



63

A0154- Morphological evolution of buckle-delamination: from telephone cord

blistertobeyond

ShichenLia,LongMab,SenjiangYuc,YongNid

aCASKeyLaboratoryofMechanicalBehaviorandDesignofMaterials,DepartmentofModern

Mechanics,UniversityofScienceandTechnologyofChina,Hefei,Anhui,P.R.China,

[email protected]

bCASKeyLaboratoryofMechanicalBehaviorandDesignofMaterials,Departmentof

ModernMechanics,UniversityofScienceandTechnologyofChina,Hefei,Anhui,P.R.China,

[email protected]

cInnovativeCenterforAdvancedMaterials(ICAM),HangzhouDianziUniversity,Hangzhou,

P.R.China,[email protected]

dCASKeyLaboratoryofMechanicalBehaviorandDesignofMaterials,Departmentof

ModernMechanics,UniversityofScienceandTechnologyofChina,Hefei,Anhui,P.R.China,

[email protected]

Understandingandcontrollingspontaneouscomplexnature’spatternformationisofbroad

interestinbothscientificandengineeringcommunities.Highresidualcompressivestressin

thin film-substrate systems usually causes structural and functional failures via buckling

instability. In particular, they could buckle and delaminate away from the substrate, and

exhibit complex buckle-delamination patterns, such as straight-sided, circular, ring-like,

telephonecordornetwork-likeblisters.Inthistalk,wefocusonelucidatingsomeuniversal

morphological features of such telephone cord blisters and beyond via a combination of

theoreticalanalysis,numericalsimulationandexperimentalvalidation.Howinterfacesliding

andridgecrackingonvariousbucklinginstabilitymodesandhowtheseinstabilitiesevolve

intocomplexbuckle-delaminationpatternsobservedinourexperimentsarediscussed.



64

A0174- Modeling and simulation of the electro-mechanical coupling behavior of

liquidcrystalelastomers

YiweiXua,YangZhangb,YiqingZhangc,YongzhongHuod


Astronautics,FudanUniversity,220HandanRoad,Shanghai,P.R.China,[email protected]







Liquid crystal elastomers (LCEs) are weakly cross-linked polymers with liquid crystal

mesogenic units and can exhibit liquid crystallinity. They are a type of soft active/smart

materialsthatcanhavelargespontaneousdeformationsinresponsetoexternalstimulusand

providesomefunctionsthatweneed.LCEscouldbepolarizedunderelectricfields,andthe

directorofLCunitscanrotatethendrivethepolymernetworktodeform.So,LCEsexhibits

interesting electro-mechanical coupling behavior. Other attributes of them include fast

responseandlowcost.ThedeformationandelectricpolarizabilityofLCEsarecouplewith

eachother.

Basedonthevariationalprinciple,wehavederivedtherelevantconstitutiveandgoverning

equationsincludingtheequationsfortheelectricfieldinducedLCdirectorreorientation.We

use this model to analyze and simulated deformations of LCE samples under electric-

mechanical loading. The results indicated that when the initial alignment is uniform, the

sampleofLCEstripeexhibituniformdeformationunderelectricfields.Notethatthereisa

criticalelectricfieldintensityatwhichtheinitiallyperpendicularlyorientedLCdirectorwill

bringinstabilityandstarttoreorient.WecallittheFreedericksztransitioninLCE.Iftheinitial

alignment is nonuniform, the stripe can bend. In both cases, the behavior of deformations

depend strongly on the initial alignment. Therefore the behavior of LCE samples could be

regulatedthroughproperdesignoftheinitialalignment.



65

A0195-Interactionsbetweentopologicaldefectnucleationandboundarybranching

inthegrowthofcurvedcrystals

LongMaa,XuepengLiub,Ai-kahSohc,LinghuiHed,YongNie

aCASKeyLaboratoryofMechanicalBehaviorandDesignofMaterials,DepartmentofModern

Mechanics,UniversityofScienceandTechnologyofChina,Hefei,Anhui,P.R.China

bCASKeyLaboratoryofMechanicalBehaviorandDesignofMaterials,Departmentof

ModernMechanics,UniversityofScienceandTechnologyofChina,Hefei,Anhui,P.R.China

cSchoolofEngineering,MonashUniversityMalaysia,SubangJaya,Malaysia

dCASKeyLaboratoryofMechanicalBehaviorandDesignofMaterials,Departmentof

ModernMechanics,UniversityofScienceandTechnologyofChina,Hefei,Anhui,P.R.China

eCASKeyLaboratoryofMechanicalBehaviorandDesignofMaterials,DepartmentofModern

Mechanics,UniversityofScienceandTechnologyofChina,Hefei,Anhui,P.R.China

Topologicaldefectnucleationandboundarybranchingincrystalgrowthoncurvedsurfaceare

twotypicalelasticinstabilitiesdrivenbycurvatureinducedstress,andseparatelydiscussed

inthepast.Inthisworktheyaresimultaneouslyconsideredduringcrystalgrowthonasphere.

Phasediagramswithrespecttocurvatureofthesphere,size,edgeenergyandstiffnessofthe

crystal for the equilibrium crystal morphologies are achieved by theoretical analysis and

validatedbyBrowniandynamicssimulations.Thesimulationresultsfurtherdemonstratethe

detailofmorphologicalevolutionbythetransitionandinterplaybetweenthesetwodifferent

stress relaxation modes. Topological defect nucleation and boundary branching not only

competeeachotherandbutalsocoexistinarangeofcombinationsofthefactors.Clarification

of the interaction mechanism provides better understanding of various curved crystal

morphologiesfortheirpotentialapplications.



66

A0216-Curvatureeffectonwrinklingandrestabilizationofhighlystretchedelastic

shells

Y.Yanga,T.Wangb,K.Wangc,F.Xud


Astronautics,FudanUniversity,Shanghai200433,P.R.China,[email protected]



cSchoolofTraffic&TransportationEngineering,CentralSouthUniversity,Changsha410075,

P.R.China,[email protected]



Rectangularsheetswithclamped-clampedboundariescanwrinkleuponuniaxialstretching

andthenreverttoflatstateuponexcessloading.Onemaywonderwhatwouldhappenona

curvedshell?Toinvestigatethecurvatureeffect,weexploreanopencylindricalshellunder

axialstretching,bothexperimentallyandnumerically.Ourresultsindicatethatthecurvature

playsan importantrole in thewrinklingandrestabilizationbehavior.Curvaturemakesthe

peakandvalleyofwrinklesnotsymmetric,which showsaglobal-localcoupling instability

phenomenon.Besides,comparedwithplanargeometry,curvaturedelaystheappearanceof

wrinkles,whileitmakesthesecondarybifurcationofrestabilizationmuchearlier.Thereexists

acriticalmaximumvalueofthecurvaturetobuckletheshell.Beyondthisvalue,nowrinkles

occur during axial stretching. Hyperelastic constitutive models (e.g., neo-Hookean and

Mooney-Rivlin laws)andsiliconrubbermembranesareusedinnumericalsimulationsand

experiments,respectively.Theresultscanpromiseanoveldirectiontocontrolthewrinkling

instabilityofmembranes.



67

A0250-Mechanicsofnanofiberspackinginvesicles:effectsoffiberlength,radius,

andelasticity

XinYia

aDepartmentofMechanicsandEngineeringScience,CollegeofEngineering,Peking

University,[email protected]

Cellular packing of one-dimensional nanomaterials, including natural cytoskeletal

microtubules,actinfilaments,syntheticnanotubesandnanowires,isoffundamentalinterest

to the understanding of a wide range of cell activities, including cell shape control, cell

movement,celldivision,andnano-cytotoxicity.Tounderstandtheunderlyingmechanicsof

cellular/intracellular packing, we perform theoretical analyses and molecular dynamics

simulationstoinvestigatehowthemorphologyandmechanicalbehaviorsofalipidvesicleare

regulatedbyencapsulatednanofibersofdifferentlengths,finiteradii,andelasticity.Astherod

lengthincreases,thevesicleevolvesfromasphereintodifferentshapes,suchasalemon,a

congadrum,acherry,abowlingpin,oratubularshapeforlong,thick,andstiffnanofibers.

Moreover,weestablishapackingphasediagrambasedonthreedistinctvesiclemorphologies,

includinga non-axisymmetricdumpling-shapedvesicle withastronglycurvednanofiber,a

cherry-shapedvesiclewithatubularmembraneprotrusionenclosingasignificantportionof

the nanofiber, and an axisymmetric lemon-shaped vesicle with a pair of protruding tips

inducedbytheencapsulatednanofiber.



68

A0298-Astatespacemethodforonsetofsurfaceinstabilityofgradedsoftmaterials

ZhigenWua,ChunxiaoZhanb

aSchoolofCivilEngineering,HefeiUniversityofTechnology,Hefei,Anhui,China,

[email protected]

bSchoolofCivilEngineering,HefeiUniversityofTechnology,Hefei,Anhui,China,

[email protected]

Surfaceinstabilitywidelyexistsinnatureandhasbeenexploitedforarangeofapplications.

Inthisstudy,basedonthegoverningequationsandbydiscretizingthematerialproperties

intopiecewiseconstantfunctions,astatespacemethodisdevelopedtosolvetheeigenvalue

problemandpredictthecriticalconditionforonsetofsurfaceinstabilityofgradedhydrogel

layers and graded elastic cylinders. For the hydrogel system, the state space solutions for

homogeneoushydrogellayers,hydrogelbilayers,andcontinuouslygradedhydrogellayersare

presented.Forgradedelasticcylinders,thestatespacesolutionsforathincylindricalshell,a

bilayeronasoftcylinder,andexponentiallygradedelasticcylindersareobtained.Thepresent

solutions are compared with the analytical solutions and/or finite element results. In

particular,atransitionofthecriticalbucklingmodeforasoftcylindercoveredbyabilayeris

illustratedclearlybythepresentmethod.Incontrasttothefiniteelementmethod,thestate

spacemethodisasemi-analyticalapproachwithgoodconvenienceandhighercomputational

efficiencyforarbitrarilygradedmaterials.



69

A0318-Theamplitude-frequencyresponseofthincompositeplateinthethermal

environment

LiuLiua,JinmingLib

aSchoolofAerospaceEngineering,BeijingInstituteofTechnology,Beijing,PRChina

bSchoolofAerospaceEngineering,BeijingInstituteofTechnology,Beijing,PRChina

This paper deals with the dynamic response of a thin composite plate under a harmonic

excitationinathermalenvironmentusingincrementalharmonicbalancemethod(IHB).The

nonlineargoverningequationsofthemotionisdevelopedbasedontheKirchhoffhypothesis

andvon-Karmangeometricnon-linearity.Galerkin'smethodisutilizedtoderivethenonlinear

governing equation of the problem with cubic nonlinearities associated with mid-plane

stretching.Anincrementalarc-lengthmethodcombinedwithacubicextrapolationtechnique

isadoptedtotracetheamplitude-frequencyresponsecurve.Theperiodicsolutionsandthe

stabilityare investigatedusingtheIHBmethod.Thesolutionofamplitude-frequencycurve

has been validated by the comparison of the results obtained by the IHB method and the

numerical method. Variation of amplitude-frequency response curve and dynamic

equilibrium position of thin plate with different temperature rising and same external

excitation are presented. The results demonstrate that the combination of thermal

deformationandthetemperaturerisinggovernsthedynamicresponse.Asthetemperature

increases, the transition of a hardening-spring type nonlinear dynamic response to a

softening-typeinthepost-criticalregionduetotwostableequilibriaforthethincomposite

plateinthethermalenvironmenthasbeenpresented.Furthermore,thedynamicbehavioris

becomingcomplicatedastheexternalexcitationfrequencyisclosetothenaturalfrequencyof

plate,whichcontainsthetypicalresonance,super-harmonic,sub-harmonicresonanceandthe

combinationofthem.



70

A0342-Photo-responsivesurfacewrinklingpatterns

JuanjuanWanga,ChuanyongZongb,HaipengJic,EnpingLiud,LeleLie,YanpingCaof,

FanXug,AndreasFeryh,ConghuaLui

aSchoolofMaterialsScienceandEngineering,TianjinUniversity,Tianjin,China

bSchoolofMaterialsScienceandEngineering,TianjinUniversity,Tianjin,China

cSchoolofMaterialsScienceandEngineering,TianjinUniversity,Tianjin,China

dSchoolofMaterialsScienceandEngineering,TianjinUniversity,Tianjin,China

eSchoolofMaterialsScienceandEngineering,TianjinUniversity,Tianjin,China

fDepartmentofEngineeringMechanics,TsinghuaUniversity,Beijing,China

gDepartmentofMechanicsandEngineeringScience,FudanUniversity,Shanghai,China

hLeibnizInstituteofPolymerResearchDresdene.V.,D-01069Dresden,Germany

[email protected]

iSchoolofMaterialsScienceandEngineering,TianjinUniversity,Tianjin,China

Recentlystimuli-responsivesurfacemicrostructureshaveattractedincreasinginterestowing

to their wide applications. Here we report the dynamic modulation of surface instability-

driven surface patterns on photo-sensitive film/substrate systems by introducing azo-

containingfunctionalgroups.Theinfluencesofthesubstrate,theincidentlightintensity,and

light polarization on surface wrinkling behavior have been investigated. Different

photoresponsivepropertiesoftheazo-containingfilmareexploitedtoaccumulate/releasethe

bilayer compressive stress, and induce the reversible switching between surface wrinkling

and dewrinkling states, which has been supported by the theoretical results. We take

advantageofthecharacteristicsofourlight-responsivecompositesystemfortheapplication

of all-optical reversible writing/erasure of (confidential) information, smart windows, and

welloptically-regulatedgratings,as demonstratedhere.This light control strategycoupled

with surface wrinkling is expected to furnish the use of azopolymers in the area of smart

surfacefabricationwhichcanfinddiversenovelapplicationsinsmartdisplay,optoelectronic

devices,andsensors,etc.



71

A0397-Aconsistentfinite-strainplatetheoryforgrowth-induceddeformationsand

instabilitiesofsoftmaterialsamples

J.Wanga,D.Steigmannb,F.F.Wangc,H.-H.Daid

aSchoolofCivilEngineeringandTransportation,SouthChinaUniversityofTechnology,

Guangzhou,Guangdong,China,[email protected]

bDepartmentofMechanicalEngineering,UniversityofCalifornia,Berkeley,CA,USA,

[email protected]

cDepartmentofMathematics,EastChinaUniversityofScienceandTechnology,Shanghai,


dDepartmentofMathematics,CityUniversityofHongKong,83TatCheeAvenue,Kowloon

Tong,HongKong,[email protected]

Growthofsoftbiologicaltissueswiththinplateforms(e.g.,leaves,petals,wingsofinsectsand

skin)canbecommonlyobservedinnature,duringwhichthesofttissuesusuallyundergolarge

deformationsandexhibitvariousmorphological instabilities.Toproperlystudythegrowth

deformationsofsofttissuesorotherkindsofsoftmaterialsamples,asuitableplatemodelis

desired. In the present work, a novel finite-strain plate theory for growth-induced large

deformations is developed. This plate theory was established within the framework of

nonlinearelasticity,takingintoaccountthegrowtheffectsandtheelasticincompressibility.

Derivation of the plate theory contains the following steps: 1) formulate the 3D governing

system of the plate sample through variational approach, which includes the mechanical

equilibrium equation and the constraint equation of incompressibility; 2) expand the

unknownfunctionsintermsofthethicknessvariable,andestablishtherecursionrelationsof

the expansion coefficients from the mechanical equilibrium equation and the constraint

equation; 3) derive the 2D vector plate equation from the lower and the upper boundary

conditionsinthe3Dgoverningsystem;4)proposetheassociatededgeboundaryconditions

fortheplateequationandderivetheweakformulationforfuturenumericalcalculations.It

canbeverifiedthat theplateequationsystemisconsistentwith theoriginal3Dgoverning

systemtoO(h2).Toshowthevalidityoftheplatetheory,twoexamplesregardingthegrowth-

induceddeformationsandinstabilitiesinthinhyperelasticplatesarestudied.Someanalytical

results are obtained in these two examples, which can be used to describe the large

deformationsandrevealtheinstabilitypropertiesofthethinplates.Furthermore,theresults

obtainedfromthecurrentplatetheoryarecomparedwiththoseobtainedfromtheclassical

FvKplatetheory,fromwhichtheadvantagesofthecurrentplatetheorycanbedemonstrated.



72

A0426-Edgewrinklingofasoftridgewithgradientthickness

YanZhaoa,YanpingCaob

aAssociateProfessor,HunanUniversity,[email protected]

bProfessor,TsinghuaUniversity,[email protected]

We investigate the edge wrinkling of a soft ridge with gradient thickness under axial

compression.Ourexperimentsshowthatthewrinklingwavelengthundergoesaconsiderable

increase with increasing load. Simple scaling laws are derived based on an upper-bound

analysistopredictthecriticalbucklingconditionsandtheevolutionofwrinklingwavelength

duringthepost-bucklingstage,andtheresultsshowgoodaccordancewithourfiniteelement

simulationsandexperiments.Wealsoreportapatterntransformationtriggeredbytheedge

wrinkling of soft ridge arrays. The results and method not only help understand the

correlationbetweenthegrowthandformobservedinsomenaturalsystemsbutalsoinspire

astrategytofabricateadvancedfunctionalsurfaces.



73

A0433-Controllablerollingandconfigurablebendinginflexiblenanomembranes

ZiaoTiana,YongfengMeib

aDepartmentofMaterialsScience,StateKeyLaboratoryofASICandSystems,Fudan

University,Shanghai,PRChina

aDepartmentofMaterialsScience,StateKeyLaboratoryofASICandSystems,Fudan

University,Shanghai,PRChina,[email protected]

Rolled-up nanomembranes can take advantage of strain-engineering and form into three

dimensional(3D)tubularstructuresforvariousapplicationsincludinglab-on-a-chip,micro-

/nanomachines, optical microcavity, sensors and actuators. Extensive attention has been

focusedontheirstrainengineering,controlandprocessrelatedtobendingbehaviors.Here

wewillintroducethemethodandprocessofrolled-upnanotech.Withspecifiedmaterialsand

processadopted,history-dependentrollingandconfigurablebendingwillbedemonstrated

for diamond helical structures and stimuli-responsive actuators. We believe that

nanomembraneorigami(e.g.rolling,bendingandstretching)couldofferanexcitingplatform

for3Dmesostructuresandtheirapplications.



74

A0483-Localizedbulginginaninflatedbilayertube

YangLiua,YangYeb

aDepartmentofMechanics,TianjinUniversity,Tianjin,China,[email protected]

bDepartmentofMechanics,TianjinUniversity,Tianjin,China,[email protected]

Gent model is believed to be an excellent model for rubber material, where an important

parameterJmsignifiesthemaximumextensibility.ItturnsoutthatarubbertubemadeofGent

materialcannotbulgeforsmallJm.Inthistalk,weconsiderabilayertubeconsistingofGent

materials. By virtue of a bifurcation condition derived for a single-layer tube of arbitrary

thickness,westudythelocalizedbulgingofthebilayertube.Ourresultsuggestsapossible

waytopreventlocalizedbulgingbybondingalayerofspecifiedthicknesswhichcannotbulge

inside or outside. Furthermore, the theoretical prediction is validated by finite element

analysis.Accordingly,theapplicabilityofthebifurcationconditionisalsoconfirmed.Onthe

otherhand,bothvolumecontrolandpressurecontrolproblemsarediscussed,andtheeffects

ofthemodulusratioandthicknessratioonthecriticalpressurePcr triggeringabulgingor

criticalvolumeVcrareinvestigated.Forthepressurecontrolproblem,wefindthatalargerPcr

attainsifthestiffpartofthebilayerincreasesoronelayerbecomesstiffer.However,thecase

ofvolumecontrolisdifferent.ItisfoundthatVcrisanon-monotonefunctionofthepercentage

ofthestiffpart.Alltheoreticalresultsarevalidatedbythecorrespondingnumericalonesusing

ABAQUS.Finally,westudythegrowthandpropagationofthelocalizedbulgingemployingthe

finiteelementmethod.Itturnsoutthattheeffectsofgeometricalandmaterialparameterson

the maximum axial stretch and propagation pressure are similar to those on the critical

pressureandvolume.



75

A0484-Wrinklingofdielectricelastomermembranes

Yu-XinXIEa,ZhendeHOUb,YibinFUc

aSchoolofMechanicalEngineering,TianjinUniversity,[email protected]

bSchoolofMechanicalEngineering,TianjinUniversity,[email protected]

cDepartmentofMathematics,KeeleUniversity,[email protected]

Apre-stretchedsheet,beingpartlycoveredwithelectrodesonbothofitssides,andtheratio

oftheelectricactivatingareaissetas ,willwrinkleunderanelectricactivation.Inthiswork,

acomputationalmodeltocharacterizethewrinklingisproposed.Basedonthismodel,some

critical values, such as the critical voltage, applied stretch, et al. can be determined. The

relationbetweenthecriticalvaluesandthenumberofwrinklesarealsoanalyzed.



76

A0493-Patternformationincurvedfilm-substratesystems

M.Potier-Ferrya,C.Fub,T.Wangc,F.Xud,R.Abdelmoulae

aLEM3,UniversitédeLorraine,Metz,France,[email protected]

bDepartmentofAeronauticsandAstronautics,FudanUniversity,Shanghai,China,

[email protected]

cDepartmentofAeronauticsandAstronautics,FudanUniversity,Shanghai,China,

[email protected]

dDepartmentofAeronauticsandAstronautics,FudanUniversity,Shanghai,China,

[email protected]

eLSPM,UniversitéParis-Nord,Villetaneuse,France,[email protected]

Stress-inducedpatternformationandpatternselectionofthinfilm/substratesystemshave

motivatedalotofresearchesduringthelastfifteenyears.Mostoftherecentpapersfocuson

planarfilm/substratebilayersandonlyfewareconcernedwithcurvedgeometry.Inthistalk,

westudythecurvatureeffectonthebucklingandpost-bucklingofsuchstructures,especially

cylindricalandsphericalsystems,fromtheoreticaltonumericalpointsofview.Thebehavior

ofsuchstructuresassociatingastifffilmandasoftcoreisinvestigatedbyusinga3Dfinite

elementmodel,thefilmbeingdiscretizedbythinshellelements.Asforpureshellstructures

(i.e.withoutacore),theinstabilityschemeisloadingandgeometry-dependent.Inthecaseof

anaxiallycompressedcylindricalpureshell,thebucklingmodesareknowntobediamond-

like and the buckling response is subcritical and highly imperfection-sensitive. The same

scheme holds with a soft core, but the response becomes supercritical and the mode

axisymmetricwithastiffercore.Itisestablishedthattheinfluenceofthecoreisgovernedby

dimensionlessparameters,Cs=(R/hf)3/2Es/EfinaxialcompressionandCth=(R/hf)3/4(L/hf)3/2

ES/Efinthecaseofathermalshrinkageofthesubstrate.Inthecaseofasphericalsystemunder

pressure, the mode keeps the same hexagonal shape as without substrate, but the post-

bucklingbehaviortendsalsotobecomesupercriticalforastiffcore.Roughlythemodeshapes

remainoftenthesamewithandwithoutsubstrate,butthepost-bucklingresponsebecomes

generally stable with a stiff substrate, what was almost never observed with pure shell

structures.



77

A0650- Non-sinusoidal buckling patterns turned by micro-structure of

film/substratesystem

ShuyiXianga,b,ChangguoWanga,b

aNationalKeyLaboratoryofScienceandTechnologyonAdvancedCompositesinSpecial

Environments,HarbinInstituteofTechnology,HarbinP.R.China

bCenterforCompositeMaterialsandStructures,HarbinInstituteofTechnology,HarbinP.R.

China

Thegeometryofthemicro-structureonthesoftsubstrate,whichisrecognizedbyanarrayof

micro-columns, can significantly influence buckling patterns and buckling load of stiff

film/soft substrate system. When the column is relatively thin, non-sinusoidal buckling

patterns will appear. With finite element eigenvalue analysis, the column is found to

participateinbendingortensiledeformation.Theresultcanbeexplainedqualitativelybythe

change of energy distribution between film and substrate with micro-structure, which is

different from the traditional film/substrate system with perfect interface. Whatever the

geometry of micro-structure is, there will exist quasi-sinusoidal buckling pattern, which is

calledupward-buckling.Inthepastresearch,thebucklingofnon-contactfilmissimplifiedas

theEulerbucklingoftheends-clampedbeams.Itisfoundthatthissimplificationonlyapplies

tothesituationwhenthecolumnisquitethin.Asthewidthofthecolumnincreases,itwill

causesignificanterrors.Therefore,wemodelthefilmasabeamelasticallyrestrainedagainst

rotation whose extreme case is ends-clamped beam or ends-fixed beam. With the help of

numeralcalculations,theelasticrotationalstiffnessappliedtothebeamcanbeobtained.The

elasticrotationalstiffnesscanbeusedasameasureoftheconstrainteffectofcolumnonthe

non-contactfilm,whichiscloselyrelatedtothegeometryofmicro-patternsandcanguidethe

predictionofbucklingload.



78

A0715-Electromechanicalcatastrophe

TongqingLuaa

aAssociateProfessor,StateKeyLabforStrengthandVibrationofMechanicalStructures,

DepartmentofEngineeringMechanics,Xi’anJiaotongUniversity,

[email protected]

A transducer is a system that couples two loads. For a membrane of dielectric elastomer

sandwichedbetweentwocompliantelectrodes,itcouplesamechanicalforceandanelectrical

voltage.Attributesofadielectricelastomertransducerincludelargedeformation,highenergy

density, lowcostandfastresponse.Applicationsincludeactuators,generatorsandsensors.

Such a two-load, nonlinear system can exhibit rich behavior of bifurcation, which can be

displayedinathree-dimensionalspace,withthetwoloadsformingthehorizontalplaneand

a state variable forming the vertical axis. In this three-dimensional space, a state of

equilibriumofthesystemunderfixedloadscorrespondstoapointonthesurface,calledthe

behaviorsurface.Thesurfaceissmooth,butthesingularitytheoryprovesthattheprojection

ofthebehaviorsurfacestotheloadplaneresultsinsingularityoftwotypes:foldandcusp.

Hereweidentifythefoldandcuspforadielectricelastomertransducerbyacombinationof

theory and experiment. We construct a three-dimensional space, with one axis being the

stretch,andtheothertwoaxesbeingtheelectricalandmechanicalloads,andthenweproject

thesurfaceontothevoltage-stretchplane,force-stretchplaneandtheforce-voltageplane.We

conducttwokindsofexperiments:electricalactuationunderaconstantforceandmechanical

pullingunderaconstantvoltage.Goodagreementbetweenthetheoryandtheexperimentis

obtainedbothonthedeformationhistoryandthedeterminationoffoldsandcusp.Thefold

andcuspareessentialinthedesignofloadingpathstoavoidorharnessthebifurcation.



79

A0844-Analysisandpredictionofunevensettlementduetoacurvedshieldmetro

tunnel

Surface settlement is a natural phenomenon of ground disturbance in subway tunnel

construction. Dissymmetrical surface settlement profiles are observed when shielding in a

curved tunnel, but these observations are quite different from the predictions of typical

formulaewhichindicateasymmetricalsurfacesettlementprofileinstraighttunnels.

Based on the field measurements from shielding subway tunnels in soft ground located in

SoutheastAsia,therelationoftheunevendistributionofjackingthrustandthemechanicsof

dissymmetricalsettlementarediscussed,andthemethodofcalculatingthedissymmetrical

settlementprofileisproposedinthisstudy.Themethodsproposedinthisarticlecanbeused

to properly predict the surface settlement induced by a single curved tunnel in similar

geological and construction conditions. The results also provide a reference set of shield

constructionparameters.



80

MS4: Computer Vision-based Studies in Structural

Health Monitoring

A0372-Systemidentificationandseismicresponsemonitoringoflarge-scalebridge

modelsusingtarget-trackingdigitalimagecorrelation

LunaNgeljaratana,MohamedA.Moustafab

aGraduateStudentResearcher,DepartmentofcivilandEnvironmentalEngineering,

UniversityofNevada,Reno

bAssistantProfessor,DepartmentofcivilandEnvironmentalEngineering,Universityof

Nevada,Reno,[email protected]

The objective of this presentation is to demonstrate the potential use of video monitoring

techniques for bridge system identification, structural health monitoring, and seismic

responseevaluationforpost-earthquakeoperationand/orrepairdecisionmaking.Thepaper

presents the results and discussion of target-tracking and digital image correlation (DIC)

monitoring of two large-scale (about 1/3 scale) two-span bridges under bidirectional

earthquakeloadingintheEarthquakeEngineeringLaboratoryofUniversityofNevada,Reno.

This study consists of two parts. The first part aims at validating and verifying response

monitoring from DIC using data from conventional sensors, i.e. string displacement

potentiometers and triaxial accelerometers. This part of the study also presents the

comprehensive monitoring and comparison of the overall seismic response of the bridge

systemsanddynamicinteractionatdifferentlevelsofseismicexcitation.Thesecondpartof

this study focuses on the structural system identification of both bridges with the

determinationofstructuralmodelparametersbasedonDICmeasuredresponsedata.Before

andaftereachseismictest,lowamplitudewhitenoisebaseexcitationtestswereconducted

and in turn, a quasi-linear response of the system was assumed to estimate the modal

parametersofanequivalentlineartime-invariant(LTI)modelforeachbridgesystem.Using

thestructuralvibrationdatarecordedbyDICandaccelerometers,threesystemidentification

methods,includingsingle-output-singleinput(SISO),singleinput-multipleoutput(SIMO)and

two output-only (SSI-DATA) are used to estimate the modal identification, i.e. frequency,

damping,andmodeshapesofthebridges.



81

A0387- Automatic bolt loose detection based on digital image processing

technology

LinshengHuoa,YuLiub

aAssociateProfessor,SchoolofCivilEngineering,DalianUniversityofTechnology,

[email protected]

bMaster’sStudent,SchoolofCivilEngineering,DalianUniversityofTechnology,

[email protected]

Boltconnectionisanimportantconnectionforminbridges,buildings,pipelines,transmission

towers,andothercivilstructures.Theloosenessoftheconnectionnodeinstructuresoften

leadstothedamageorevencollapseofstructuralsystems,hencethemonitorandinspection

ofboltsconnectioninstructuresareveryimportant.Ingeneral,looseboltscouldbevisually

inspected by inspectors to assess health status. However, traditional visual inspections are

time-consuming,cumbersomeandinaccurate.Withthedevelopmentandmaturityofimage

processingtechnology,imageprocessingcouldbeappliedtolooseboltdetectionoflarge-scale

structures, which is an automatic and rapid detected method to ensure the safety during

detection process This paper proposes a method of automatic bolt looseness detection, all

testing processes are automatically completed in one step, including preprocessing, edge

recognition,imagecorrectionandanglecalculation.Inthisstudy,weidentifiedtherotation

angleofthenutfromtheimages,bythefollowingsteps:First,cameracaptureboltphotos.and

then, the images were corrected by image processing techniques and bolt edges were

extracted.Finally,determiningtheangleofeachboltandcalculatingtherotationangle.We

verified the applicability of this method through a set of experiments. The results

demonstrated that the measurement error of this method was less than 5.5%, which

suggestedthatthismethodcouldaccuratelydetecttheloosenessofbolts.



82

A0910- An algorithm for identification of structural parameters and excitation

forcesusingnoncontactvision-baseddisplacementmeasurements

YingLeia,XianzhiLib,JubinLuc

aDepartmentofCivilEngineering,XiamenUniversity,XiamenChina

bDepartmentofCivilEngineering,XiamenUniversity,XiamenChina

cDepartmentofCivilEngineering,XiamenUniversity,XiamenChina

The identification of structural parameters and external excitation forces is important for

structuralhealthmonitoring(SHM).Duringthepasttwodecades,althoughrecentresearches

have demonstrated some maturity for vibration-based SHM, the requirement for installing

densepoint-wisesensor(e.g.,accelerometers,straingauges,LVDT,etc.)networkswouldtake

considerable measurement cost, time and effort, and traffic disruptions. Due to the recent

advancesinsensortechnologyandcomputationalcapabilityofcomputers,theuseofvision-

based approaches for condition assessment of structures offer a promising alternative

opportunitytoimprovetheresilienceofstructuralsystems.Incontrasttotheconventional

extensively used point-wise sensors, displacements of a large number of points can be

extractedbycomputervision.Onemajoressentialtaskistofurtheradvancethenoncontact

vision sensor technology for practical SHM applications, by validating the feasibility of the

simultaneousidentificationofstructuralstiffnessandexternalexcitationforcesutilizinglow-

costvision-baseddisplacementdata.Inthispaper,therecentgeneralizedextendedKalman

filter,which recentlyhasbeenproposedbytheauthors, isextendedtoinvestigatethereal

time simultaneous identification of both structural stiffness and external excitation forces

utilizingvision-baseddisplacementmeasurementidentificationofstructuralparametersand

excitationforcesusingdisplacementmeasurements.Anumericalexampleisinvestigatedto

evaluate the accuracy of the proposed algorithm. Effects of different noise levels, sensor

numbersandinitialestimatesofstructuralparametersontheidentifiedresultsarestudiedin

detail.Theproposedalgorithmcanbeintegratedwithcomputertechnologyforefficientand

low-cost periodic or long-term performance assessment of civil infrastructures for the

resilienceofstructuralsystems.



83

MS5: Nonlinear Stochastic Structural Dynamics

Methodologies for Complex Engineering Systems

A0659-Anefficientstochasticcomplexmodalanalysistechniquefornonclassically

dampedandnonlinearmdofstructuralsystems

IoannisP.Mitseasa,IoannisA.Kougioumtzogloub,MichaelBeerc

aInstituteforRiskandReliability,LeibnizUniversityHannover,Callinstr.34,30167,

Hannover,Germany,[email protected],[email protected]

bDepartmentofCivilEngineeringandEngineeringMechanics,TheFuFoundationSchoolof

EngineeringandAppliedSciences,ColumbiaUniversity,500West120thStreet,NewYork,

NY10027,USA.e-mail:[email protected]

cInstituteforRiskandReliability,LeibnizUniversityHannover,Callinstr.34,30167,

Hannover,Germany

Anovelinelasticmodaldecompositionmethodforrandomvibrationanalysisinallingnment

withcontemporaryaseismiccodeprovisions(e.g.,EC8)consideringnon-classicallydamped

andnonlinearmulti-degree-of-freedom(MDOF)systemsisdeveloped.Relyingonstatistical

linearization and state-variable formulation the complex eigenvalue problem considering

non-classicallydamped,nonlinearMDOFstructuralsystemssubjecttoavectorofstochastic

seismic processes characterized by power spectra compatible in a stochastic sense with a

givenelasticresponseuniformhazardspectrum(UHS)ofspecifiedmodaldampingratio,will

beaddressed.Equivalentmodalproperties(EMPs)of the linearizedMDOFsystem,namely

equivalentpseudo-undampednaturalfrequenciesandequivalentmodaldampingratioswill

be provided. To this aim, the system response covariance matrix needs to be estimated.

Subsequently,theEMPsofthestructurewillbeutilizedtogetherwiththeappropriatemean

response elastic UHS for determining peak nonlinear responses. Note that a significant

advantageofthetechniquerelatestotheinvolveddecouplingandthederivedEMPswhichare

notonlyabletocapturethetrendoftheinelasticbehavior,buttheyarealsoclearlyamenable

toaphysicalmeaning.



84

A0802-Ahybridsem‒smmethodforsubwayrandomdynamicloadsinducedbythe

frequency-dependentdynamicpropertiesofrailpads

KaiWeia,b,YinlingDoua,b,FanYanga,b,ShaohuaWanga,b,PingWanga,b

aMOEKeyLaboratoryofHigh-speedRailwayEngineering,SouthwestJiaotongUniversity,

Chengdu,China

bSchoolofCivilEngineering,SouthwestJiaotongUniversity,Chengdu,China

[email protected]

Foraneffectiveandaccuratepredictionofthemainexcitationsourceofsubwayenvironment

vibrationsandwheel‒railnoise(i.e.,therandomdynamicloadsofsubwayvehicles),according

totheperiodicityofrail‒fastenersystemandhigh-frequencyelasticwavecharacteristicsof

rail, a hybrid SEM‒SM method is proposed. Based on the measurement of the frequency-

dependentdynamicpropertiesofDTIIIrailpadsfrequentlyusedinChina’ssubway,thehybrid

SEM‒SMmethodwasusedtoinvestigatetheinfluenceofthefrequency-dependentdynamic

properties of DT III rail pads on subway random dynamic loads. There are four main

conclusions.(1)ThestoragestiffnessofDTIIIrailpadwithin0.1–10000Hzat20°Chavean

approximatelinearrelationwithfrequencyinalogarithmiccoordinatesystem,whiletheloss

factors of DT III rail pad firstly increase and then decrease in frequency domain. (2) The

frequency-dependent dynamic properties of rail pads can increase the subway random

dynamicloadsintwodominantfrequencydomains,32‒80Hzand500‒1250Hzrespectively.

Thus, the frequency-dependent dynamic properties of rail pads should be considered in

predictionofsubwayenvironmentalvibrationandwheel–railnoise.(3)Theinfluenceofthe

frequency-dependentdynamicpropertiesofrailpadsonsubwayrandomloadsisequivalent

totheeffectofthevehiclespeedincreaseof92km/h,whiletheinfluenceoftheshortwave

trackirregularityonsubwayenvironmentvibrationsislessthantheeffectofthefrequency-

dependentdynamicpropertiesofrailpadsunlessthereisaprettyseriousshortwavetrack

irregularity.(4)TheproposedhybridSEM‒SMmethodinwhichonlyoneelementisrequired

tocomputethehigh-ordervibrationmodesofinfiniterailisappropriateforhigh-efficiency

analysisofsubwayrandomdynamicloadsinhighfrequencies.



85

A0890- Stochastic response analysis of an offshore wind turbine under the

excitationsrepresentedbystochasticharmonicfunction

YupengSonga,JianbingChenb

aPh.D.student,CollegeofCivilEngineering,TongjiUniversity,[email protected]

bProfessor,StateKeyLaboratoryofDisasterReductioninCivilEngineering,

[email protected]

Simulationofthewindandwaveloadsactingonanoffshorewindturbineisoneofthemost

criticaltasksinitsstructuraldesignandreliabilityassessment.Thespectralrepresentation

method(SRM)isthemostwidelyusedmethodatpresent,which,however,involvesalarge

numberofrandomvariablesandresultsinmuchcumbersomenessinthereliabilityanalysis

of the system. To reduce the random variables in the simulation of fluctuating wind speed

fields,thestochasticharmonicfunction(SHF)representationwasdevelopedrecentlybased

onawavenumber-frequencyjointspectrum.ComparedtotheSRM,intheSHFrepresentation

method both the phase angles and frequencies/wavenumbers are regarded as random

variables. Along this line, the wave surface elevation is also simulated through the SHF

representation in the present paper. Besides, the subdomains involved in the SHF

representation are specified by the Voronoi cell partitioning scheme after determining the

representative points by the acceptance-rejection method. In this way, the number of the

randomvariablesandthecomputationaleffortsaredramaticallyreducedsimultaneously.For

illustrativepurpose,thestochasticdynamicresponseanalysisofanoffshorewindturbineis

addressed,demonstratingtheeffectivenessoftheproposedmethod.



86

MS6: Damage Modelling of Engineering Structures

A0169- Concurrent fatigue crack growth and vehicle-bridge dynamics analysis

usingtime-basedsybcycleformulation

YangYua,YongmingLiub,KarthikRajanVenkatesanc,BiancaKuriand

aPostdoctoralFellow,SchoolforEngineeringofMatter,Transport&Energy,ArizonaState


bProfessor,SchoolforEngineeringofMatter,Transport&Energy,ArizonaStateUniversity,

[email protected]

cPh.D.student,SchoolforEngineeringofMatter,Transport&Energy,ArizonaState


dMasterstudent,SchoolforEngineeringofMatter,Transport&Energy,ArizonaState


Bridgestructuresareproneto fatiguedamagesas theyundergotraffic loading.Thebridge

responses under vehicle loading are usually complex due to the interaction between the

vehicleandbridge.Theclassicalcycle-basedformulationforfatiguecrackgrowthhasintrinsic

difficulties in dealing with these complex loading spectrums since they often cannot be

describedascyclic.Inthisstudy,atime-basedsubcycleformulationforfatiguecrackgrowth

isintroducedtoaddressthisdifficulty.Theproposedmodelincludesthreemajorcomponents:

1)atime-basedcrackgrowthkineticsfunctionatthesubcyclescale;2)anefficientcracktip

opening displacement (CTOD) estimation method; 3) a crack tip plasticity zone tracking

algorithms for crack opening level determination of a moving crack. For demonstration, a

simplysupportedsteelgirderbridgeisadopted.Numericalsimulationisconductedusingfull-

scalethree-dimensionalvehicleandbridgemodels.Aninitialcrackisassumedtobelocated

onthebottomflangeofthesteelgirderandthecrackgrowthisanalyzedusingtheproposed

method.Aparametricstudyisconductedtoinvestigatetheeffectsofroadsurfacecondition,

vehicleweight,vehiclespeed,vehicledynamics,andtrafficvolumeonthecrackgrowthrate.



87

A0406-Datanormalizationanddamagedetectionframeworkforoperationalwind

turbinesinvaryingoperationalenvironments

OmidBahramia,JeromeLynchb

aGraduateStudent,DepartmentofCivilandEnvironmentalEngineering,Univ.ofMichigan

bProfessor,DepartmentofCivilandEnvironmentalEngineering,Univ.ofMichigan

([email protected])

Wind turbines are complex engineered structured designed to convert wind energy into

electricalenergy.Theirlargesizecoupledwithanextremelydemandingloadenvironmentcan

leadtodamageoverthelife-spanofthewindturbine.Giventheirhighcostsandimportance

in providing electrical energy, there is growing interest in monitoring wind turbines and

assessing their health using monitoring data. A major challenge associated with structural

healthmonitoring(SHM)ofwindturbinesisthevaryingnatureoftheirenvironmentaland

operationalconditions(EOC).ThisworkexploresanapproachtoextractingEOCdatafrom

the measured structural response of wind turbines. A data normalization process is

performedbyclusteringEOCfeaturesmeasuredusingaGaussianmixturemodel.With the

EOCspacedelineatedbyclustering,datafromanoperationalturbineinanunknownstateis

assigned by EOC features to a cluster. Damage-sensitive features also extracted from

monitoringdataisthencomparedtothebaselinehealthystateofthestructureforagivenEOC

clustertohypothesizetheconditionofthestructure.Thisframeworkisvalidatedusingasmall

5 kW wind turbine located in Los Alamos, New Mexico. A wireless monitoring system is

installedontheturbinetomeasurethelateralvibrationoftheturbinetower.Theacceleration

datacollectedisusedtoassesstheconditionofthestructure.Acontrolleddamagestateis

introducedintheformofasoftspringintroducedattheturbinefoundation.Thestudyfinds

themethodspresentedareeffectiveinclassifyingthehealthofthestructure.



88

A0451- Simulating time-dependent quasi-brittle failures based on a multilinear

releasingmechanismofviscousforcefields

JinxingLiua

aFacultyofCivilEngineeringandMechanics,JiangsuUniversity,XuefuRoad301,Zhenjiang,

Jiangsu,China,

The time-dependent progressive failure processes in heterogeneous brittle materials are

modeledbyconsideringthetemporalstressredistributionmechanismduetolocalbreakages.

The influence of local breakages lies in two successive kinds of stress redistributions: (1)

Internalforcesinthebreakingelementisassumedtoreleaseinfinitelyfastwhencompared

with external loadings, while the specimen takes time to deform correspondingly due to

materialviscosity.Thisdeformationdelayisimplementedbyintroducingaviscousforce(VF)

fieldalloverthespecimen.(2)ThesecondisthegradualreleaseofVFfieldsstoredpreviously

which is approximated as a multilinear process. The algorithm only includes linear

computations and is free of nonlinear iterations. Numerical results of uniaxial

tensile/compressive,anchorboltpull-outandBraziliantestsshowthattheproposedmodelis

capableofovercomingtheover-brittleissueinexistinglatticemodelsandcapturingthestrain

ratesensitivity,whichagreewellwithexperimentalobservations.



89

A0477-Machinelearningbasedmultiscalemodelingofbackwarderosionpiping

AlessandroFascettia,CaglarOskayb

aLecturer,FacultyofScienceandEngineering,TheUniversityofWaikato(Hamilton,New

Zealand),[email protected]

bProfessor,DepartmentofCivilandEnvironmentalEngineering,VanderbiltUniversity

(Nashville,TN,USA),[email protected]

The presented research provides a novel multiscale modeling framework to simulate the

evolutionofBackwardErosionPiping(BEP)processesinFloodProtectionSystems(FPSs).

Numericalsimulationsareperformedatthelocalscalebymeansofamultiphasedescription,

andresultsareusedasthetrainingsetforamulti-layerMachineLearning(ML)algorithmto

bridge the information between scales. The capability of generating results in a fast, yet

accurate manner is exploited in the parametric study of the proposed physical model.

AccuracyofthesotrainedMLalgorithmisdemonstratedbycomparingresultsobtainedfrom

detailednumericalmodels.Themultiscaleapproachisalsoemployedintheconstructionof

responsetables,whichpresentresultsinaconvenientgraphicalfashion.Thegoalofthisstudy

istoallowforreal-timepredictionsoftheoverallresponseatthesystemscalelevel.Acase

studyispresentedwheretheentireportionoftheNashvilleMetroLeveeSystemisstudiedin

aspanofayear,toassessthelikelihoodofBEPtoundermineitsstability.



90

A0651-Analysisofseismiccollapseofhigh-risestructureundernear-faultpulse-

typegroundmotion

TiancanHuanga,MinLib

aEarthquakeEngineeringResearch&TestCenterofGuangzhouUniversity,

[email protected]

bEarthquakeEngineeringResearch&TestCenterofGuangzhouUniversity,

Thenear-faultpulse-typegroundmotionshasgreatpotentialdamageabilitytothehigh-rise

structure, which will increase the risk of seismic collapse of structures. In this study,

incremental dynamic analysis method combined with material damage model was used to

quantitatively analyze the seismic collapse of a high-rise building subjected to near-fault

pulse-typegroundmotions.Inparticular,thepaperfocusesontheanalysisoftherelationship

betweentheP-delteeffectandtherelatedenergychanges,which.arecloselyrelatedtothe

structuralcollapse.



91

A0827- Scaling effects for dynamic responses with application to buried arches

subjectedtointernalblast

SzeDaiPanga

aAssociateProfessor,NationalUniversityofSingapore,[email protected]

Earth covered arch structures provide an economical solution for storing ammunition and

otherexplosivematerials.Toassesstheblastresistanceofthestoragestructure,experimental

study is always necessary, because any analytical or numerical models require verification

basedonexperimentalresults.Ascomparedtofull-scaleexperiments,scaleddownmodeltest

isamuchcheaperandeasieralternative.So far,mostof thescaledmodelexperimentsare

conductedusingreplicascalingmethod,inwhichthemodelsaregeometricallyscaledfrom

the prototype while keeping the material properties unchanged. However, three common

phenomena,namelystrainrateeffect,concretefractureandgravity,violatethereplicascaling

law,andhencetheymaypotentiallydiminishtheaccuracyofthescalingresults.

Thisresearchiscarriedouttofirstevaluatetheeffectofeachnon-scalingphenomenoninthe

blastloadedburiedarches,andthen,forthemoreprominentsourcesofscalingdistortions,to

proposenewscalingmethodstoreducethescalingerrors.Numericalsimulationsshowthat

thestrainrateeffectandconcretefracturearethetwomajorscalingdistortions,whereasthe

scaling errors due to gravity effect is insignificant. Therefore, new scaling methods are

requiredtoreducethescalingerrorsduetostrainrateeffectandconcretefracture.

Anewsetofscalinglaw,thestrainratescaling,isdevelopedtoreducethescalingerrorsdue

tothestrainrateeffectinsteelmaterial.Numericalsimulationsareperformedonblastloaded

buriedsteelarchestoprovethesuperiorscalingperformanceofthestrainratescalingover

the classical replica scaling. The strain rate scaling method is also applicable to other

dynamically loaded steel structures, and the wide applicability of the new scaling law is

demonstratedthroughnumericalsimulations.Aseriesofmodelandprototypedrop-weight

impactexperimentsareperformedtoillustratetheapplicationprocessandtofurthervalidate

thestrainratescalinglaw.Thestrainratescalinglawisalsoextendedtosituationswherethe

modelandtheprototypearebuiltfromdifferentsteelgrades.



92

A0879- Constitutive modeling of ductile and brittle failures of semicrystalline

polymers

Jia-LiangLea,AnuTripathib,SusanMantellc

aDepartmentofCivil,Environmental,andGeo-Engineering,UniversityofMinnesota

bDepartmentofCivil,Environmental,andGeo-Engineering,UniversityofMinnesota

cDepartmentofMechanicalEngineering,UniversityofMinnesota

Semicrystalline polymers, such as high density polyethylene (HDPE), have become

increasinglypopularininfrastructureapplicationsduetotheirlowcostandhighstrength-to-

weightratio.However,manyoftheseengineeringapplicationsinvolvecorrosiveenvironments,

which cause material embrittlement and eventually catastrophic structural failures. This

studyaimstodevelopaconstitutivemodeltocapturethetransitionbetweentheductileand

brittlefailuresofHDPEbasedonthemolecularweightandcrystallinity.Anelaso-viscoplastic

model is used to capture the ductile behavior due to the intermolecular resistance of the

crystalline and amorphous phases, as well as the entangled network resistance of the

amorphousphase.Thecontributionsfromtheindividualphasestotheoverallloadresistance

is governed by the polymer crystallinity. These plastic deformation mechanisms lead to

networkdisentanglement,crystalbreakdown,andinitiationofmicro-voids.Thevoidgrowth

inthecrystallineandtheamorphousphasecausestheductilefailureofthepolymer.Whenthe

maximumprincipalstressintheamorphousphasereachesacriticalvalue,micro-voidswould

localizeintocrazes,andthegrowthandbreakdownofthesecrazescausecrackpropagation

signifying a brittle failure mode. To capture this transition of the failure mechanism, a

continuum model of crazing damage is combined with the elasto-viscoplastic model. The

model parameters are explicitly related to the molecular weight of the HDPE, and its

dependence is calibrated by using the uniaxial tensile tests at various deformation rates,

crystallinities,andcorrosionlevels.Theconstitutivemodelisvalidatedbythefiniteelement

simulationsofdoubleedgenotchtestsfordifferentcorrosionlevels.Itisshownthatthemodel

can capture well the time-dependent stress-strain behavior and predict the transition

betweentheductileandbrittlefailuremodesofHDPEinacorrosiveenvironment.



93

MS7: Non-Deterministic Modelling and Uncertainty

Management in Structural Dynamics and Vibroacoustics

A0044- Structural reliability and reliability sensitivity analysis of extremely rare

failureeventsbycombiningsamplingandsurrogatemodelmethods

PengfeiWeia,JingwenSongb

aAssociateProfessor,SchoolofMechanics,CivilEngineeringandArchitecture,Northwestern

PolytechnicalUniversity,[email protected]

bPh.Dstudent,SchoolofAeronautics,NorthwesternPolytechnicalUniversity,

[email protected]

Theaimofthispaperistostudythereliabilityanalysis,theparametricreliabilitysensitivity

(PRS)analysisandtheglobalreliabilitysensitivity(GRS)analysisofstructureswithextremely

rare failureevents.Firstly, theGRS indicesarerestudied,andweshowthat the totaleffect

indexcanalsobeinterpretedastheeffectofrandomlycopyingeachindividualinputvariable

on the failure surface. Secondly, a new method, denoted as AK-MCMC, is developed for

adaptivelyapproximatingthefailuresurfacewiththeactivelearningKrigingsurrogatemodel

aswellasthedynamicallyupdatedMonteCarlo(MC)orMarkovChainMonteCarlo(MCMC)

populations.Thirdly,theAK-MCMCprocedurecombinedwiththequasi-optimalimportance

sampling(IS)procedureisextendedforestimatingthefailureprobability,thePRSandGRS

indices. For estimating the GRS indices, two new IS estimators are derived. The AK-MCMC

procedurecanberegardedasacombinationoftheclassicalAK-MCSandsubsetsimulation

(SS)procedures,butitismuchmoreeffectivewhenappliedtoextremelyrarefailureevents.

Resultsoftestexamplesshowthattheproposedmethodcanaccuratelyandrobustlyestimate

theextremelysmallfailureprobability(e.g.,1e-9)aswellastherelatedPRSandGRSindices

withseveraldozensoffunctioncalls.



94

A0079- Model-form and parameter uncertainty quantification in structural

vibrationsimulationusingfractionalderivatives

BaoqiangZhanga,c,QintaoGuob,YanWangc,MingZhand

aSchoolofAerospaceEngineering,XiamenUniversity,[email protected]

bCollegeofMechanicalandElectricalEngineering,NanjingUniversityofAeronauticsand

Astronautics,[email protected]

cWoodruffSchoolofMechanicalEngineering,GeorgiaInstituteofTechnology,

[email protected]

dCollegeofMechanicalandElectricalEngineering,NanjingUniversityofAeronauticsand

Astronautics

Extensiveresearchhasbeendevotedtoengineeringanalysisinthepresenceofonlyparameter

uncertainty.However,inmodelingprocess,model-formuncertaintyarisesinevitablydueto

thelackofinformationandknowledge,aswellasassumptionsandsimplificationsmadeinthe

models. It isundoubtedthatmodel-formuncertaintycannotbe ignored.Tobetterquantify

model-formuncertaintyinvibrationsystemswithmultipledegreesoffreedom,inthispaper,

fractional derivatives as model-form hyperparameters are introduced. Two types of

hyperparameters for damping and elasticity force are differentiated. A new general model

calibration approach is proposed to separate and reduce model-form and parameter

uncertaintybasedonmultiplefractionalfrequencyresponsefunctions.Thenewcalibration

method is verified through a simulated system with two degrees of freedom. The studies

demonstratethatthenewmodel-formandparameteruncertaintyquantificationmethodis

robust.



95

A0129- Dynamic response of a train-bridge intraction system due to sudden

decelerationinhighspeedrailwaysystems

XuzhaoLUa,Chul-WooKIMb,Kai-ChunCHANGc

aPh.Dcandidate,DepartmentofCivilandEarthResourcesEngineering,KyotoUniversity,

[email protected]

bProfessor,DepartmentofCivilandEarthResourcesEngineering,KyotoUniversity,

[email protected]

cJr.AssociateProfessor,DepartmentofCivilandEarthResourcesEngineering,Kyoto


Thisstudyisintendedtoinvestigatedynamicresponsesofatrain-bridgeinteractionsystem

withasuddendecelerationutilizingthecommercial finiteelementsoftwareABAQUSasan

emergencybrakeoftrainisacrucialtechnicalissueinhighspeedrailwaysystem.Fewstudies

have investigated dynamic responses of train-bridge interaction system with a series of

decelerationtraincars.Therefore,thisstudyalsoexaminestheinfluenceofemergencybrake

ofaseriesoftraincarsonthebridgestrucure.AtypicalShinkansensystem—Japanesehigh-

speedrailway,whichconsistsof16carsanda3-blockbridgeisthetargetrailwaysystemto

beinvestigated.Thecarcomprisescarbodies,bogiesandwheelsets,whichareallmodelled

byrigidbodiesandconnectedwithspringsanddampers.Thebridgeismodeledwithsolid

elements.Asfortheinteraction,apenaltyfrictionmethodisappliedtosimulatetheextreme

locking brake case when sliding happens between wheels and tracks. This model was

compared with a general deceleration model. The emergency brake showed considerable

effectsonlongitudinalaccelerationoftrainvehiclesandverticaldynamicresponsesonpre-

specifiedpointsofthebridge.Itisnoteworthythatobservationsfromthisstudycanprovide

referenceinformationofimpactfactorsandridingcomfortoftrainfordesigncodes.Moreover,

the proposed numerical approach encourages to extend the application to investigation of

trainandbridgeresponsesinextremesituationssuchasderailment.



96

A0145- A robust approach to quantifying forecasting uncertainty using proxy

simulations

KendraVanBurena,ScottCoganb,FrançoisHemezc

aTechnicalStaffMember,XComputationalPhysicsDivision(XCP),LosAlamosNational

Laboratory,LosAlamos,[email protected]

bResearchFellow,UniversiteBourgogneFranche-Comte,Besançon,France.

[email protected]

cTechnicalStaffMember,XTheoreticalDesign(XTD)Division,LosAlamosNational

Laboratory,LosAlamos,[email protected]

When using numerical models, analysts are often confronted with the situation whereby

simulationpredictionsareusedtoinformdecision-makinginadomainwhereexperimental

dataareunavailable.Insuchcases,thenumericalmodelistrustedtopredictintheapplication

domainsimplybecauseithasbeenshowntobetrustworthyinthevalidationdomain,where

experimentaldataareavailable.Thedifferencebetweenapplicationandvalidationdomains,

however,canoftenresultinsignificantextrapolationofthemodelthatreducesconfidencein

predictions in the application domain, for example, when a model validated against linear

vibrationdataisusedtopredictin-serviceperformancewhenanonlinearresponseisinduced.

Thechallengeofpredictingintheapplicationdomainisfurtherexacerbatedduetothefact

thatcalibrationcanresultinparameteruncertaintyinducedby(i)modelformerror,whichis

the inability of the numerical model to exactly replicate physics, and (ii) lack of model

distinguishability,whichoccurswhendifferentsetsofparametervaluesareabletoreplicate

theexperiments.Forthesereasons,calibrationresultsinparametervaluesthatreflectabest

fit to experimental data rather than converging to their "true" values. Thus, calibration

introduces compensating effects to parameter values that must be accounted for when

predictingineitherthevalidationorapplicationdomains.

Although the inherent dangers of prediction extrapolation are widely recognized, few

methods are available to actually establish its credibility for a given application. It is our

contention that numerical predictions should be as robust as possible to sources of

uncertaintywhenpredictingintheapplicationdomain.Herein,weproposeanapproachto

calibrationthatutilizes info-gapdecisiontheorytoprovideameasureofrobustnesstothe



97

combined effects of extrapolation and compensating errors. Rather than searching for

parametervaluesthatbest-fitexperimentaldatainthevalidationdomain,ourmethodology

is to search for parameter values that are robust in both the validation and application

domains.Satisfyingboundaries,whichareisocontoursoftheparametervaluesthatproduce

fidelity-equivalentsolutionsintheparameterspace,canbecomparedinboththecalibration

domainandtheapplicationdomaintoformulatearobustnessindicator.Doingsocaninform

thedegreetowhichcalibrationerrorscanbetoleratedwhilestillensuringacriticallevelof

forecastingrobustness.Thebasicpremiseisthatrobustnesstotheeffectsofcompensating

errorsandextrapolationcanbequantifiedusingpredictionvariabilitywhenparametervalues

are allowed to vary away from their calibrated settings. Robust calibration is performed

considering the ability to replicate experimental data in the validation domain, and proxy

simulationsrepresentativeoftheapplicationdomain.Ourmethodologyisdemonstratedusing

asimplifiedstructure.Ourapproachhighlightsthefactthat,confidenceinmodelpredictions

intheapplicationdomainisincreasedwhenpredictionsremainasrobustaspossiblegiven

theunavoidablesourcesofuncertaintyinthenumericalmodel.



98

A0323-Modelingtheasymmetricdependantsoilvariables

YiZhanga

aAssociateProfessor,DepartmentofCivilEngineering,TsinghuaUniversity,

[email protected]

Multivariate information of soil parameters is quite important for the design and risk

assessment of geotechnical engineering problems. It is necessary to have an accurate and

realisticstatisticalmultivariatemodelforrepresentingthesoilpropertiesandthusevaluating

the soil conditions. Thus, advanced multivariate modeling of soil parameters could help to

improve the geotechnical engineering practice. In this paper, the asymmetric copulas are

introducedtomodelthegeotechnicalsoildata.Comparedtoextensivepreviousresearchon

theuseofsymmetriccopulasonthemodelingofengineeringdata,thisstudyisfocusingon

capturingasymmetricdependenciesamongthenaturalsoilparameters,whicharecriticalto

engineeringdesigns.Acopula-basedmultivariateprobabilisticmodelisbuiltbasedonasetof

collected samples from a granite residual soil from Portugal. Several asymmetric copula

functions,capableofcapturingnonlinearasymmetricdependencestructures,aretestedand

analyzed. The fundamental information on tail dependencies and measures of asymmetric

dependenciesarealsoexploited.Todemonstratetheadvantagesofasymmetriccopulas,the

asymmetriccopulaconceptiscomparedwiththetraditionalcopulaapproachesformodeling

sitesoildata.Theperformanceoftheseasymmetriccopulasisdiscussedandcomparedbased

ondatafittingandextremevaluecharacterizations.



99

A0414- Non-probabilistic model of transmissibility functions based on complex

ratiointervalarithmetic

Meng-YunZhaoa,Wang-JiYanb,Wei-XinRenc

aDepartmentofCivilEngineering,HefeiUniversityofTechnology,[email protected]

bDepartmentofCivilEngineering,HefeiUniversityofTechnology,[email protected]

dDepartmentofCivilEngineering,HefeiUniversityofTechnology,[email protected]

Due to its clear physical interpretation in characterizing the dynamics of a system,

transmissibility functions play important roles in many related fields such as structural

damage detection and modal analysis. Uncertainty quantification for transmissibility

functions is of practical importance in improving the robustness of their real applications.

Interval analysis has been a popular mathematical tool to deal with the uncertainties of

engineeringproblemsinwhichonlythelowerandupperboundsofuncertainparametersare

required.Determiningtheboundsforanintervalcouldbeeasierandmorestraightforward

thantheidentificationofprobabilitydistributions.Therefore,intervalanalysisisappealingfor

thecaseswhenprobabilityinformationismissing.Definedastheratiosoftwocomplex-valued

randomvariables,transmissibilityfunctionsarecomplexratiorandomvariables.Directuseof

thearithmeticoperationrulesofintervalanalysistocomputecomplexintervaldivisioncan

leadtosignificantintervalexpansion,whichhindersitsrealapplicationssignificantly.Inthis

paper,weproposeanefficientalgorithmtoaddresstheissuesaforementioned.Thereciprocal

ofthedenominatoriscomputedwithmaximumaccuracybymappingcomplexintervalintoa

regionboundedbyfourcirculararcs.Asaresult,theintervaloftransmissibilityfunctionscan

beachievedbymultiplyingasmallestrectangularregioncontainingtheaboveregionwiththe

numerator.MonteCarlosimulation(MCS)isusedtoverifytheproposedscheme.Furthermore,

anumberofsamplesoftransmissibilityfunctionsobtainedfromfieldtestdataofabridgeis

usedtoverifytheaccuracyandefficiencyofthealgorithm.Resultsindicatethat,bycomparing

withthesubintervalmethod,thealgorithmisabletoefficientlysuppressintervalexpansion.

Therefore, the proposed methodology can be used to quantify the uncertainty of

transmissibilityfunctionseffectively.



100

A0439- The bhattacharyya distance: a novel uncertainty quantification metric in

stochasticsensitivityanalysis

SifengBia,MatteoBroggib,MichaelBeerc

aInstituteforRiskandReliability,LeibnizUniversitätHannover,[email protected]

bInstituteforRiskandReliability,LeibnizUniversitätHannover,[email protected]

cInstituteforRiskandReliability,LeibnizUniversitätHannover,[email protected]

It has been widely accepted that uncertainties should be appropriately considered in the

campaign of verification and validation (V&V) for computational models. Uncertainty

quantification(UQ)metricsareconsequentlysignificantwiththeexpectationtoprovidean

elaboratemeasurementoftheuncertainty information.Byprovidinganabsolutegeometry

distance between two single points, the Euclidian distance is probably the most common

metric especially in deterministic model updating and sensitivity analysis approaches.

Alternatively, the Bhattacharyya distance is a stochastic metric between two samples

considering their probabilistic distributions. The Bhattacharyya distance is clearly more

comprehensiveforuncertaintytreatment,however,itsapplicationinV&Visquitelimitedin

thecurrentliteratures.Thisisnotonlycausedbyahugecalculationburdenbutalso,more

critically,causedbyitsstochasticcharacterwhenevaluatingthedistancebetweentworandom

samples.

SensitivityanalysisisakeycomponentofV&V,generallyperformedpriortomodelupdating,

with thepurpose toevaluateandrank thesignificanceofeachparameteraccording to the

quantityofinterest(QoI).Toomanyinvestigatingparametersleadstoahugecalculationcost,

andevenrenderstheupdatingoftruesignificantparametersintractable.Consequently,the

objectiveofthisworkisastochasticsensitivityanalysisapproachinwhichtheBhattacharyya

distance is perfectly embedded as UQ metric. Since the model updating process can be

deterministic or stochastic, the investigating parameters and QoI vary among various

applications. In this work, not only the parameters themselves, but also their uncertainty

characteristics,e.g.meanandvariance,areinvestigatedwiththehelpofthenovelUQmetric.

Statisticaltechniquessuchasanalysisofvarianceanddesignofexperimentsareinvolvedin

the framework so that the significance factors of the uncertain parameters are evaluated.

Feasibility of the novel UQ metric in association with the stochastic sensitivity analysis is

demonstratedinsimulationexamples.



101

A0459- Modal identification of structural dynamics using sparse representation

underunderdeterminedcondition

WeiGuana,L.L.Dongb,JianYanc,J.Zhoud

aPh.D.Student,SchoolofAerospace,Xi’anJiaotongUniversity,Xi’an,China,

[email protected]

bAssociateprofessor,SchoolofAerospace,Xi’anJiaotongUniversity,Xi’an,China,

[email protected]

cPh.D.Student,SchoolofAerospace,Xi’anJiaotongUniversity,Xi’an,China,

[email protected]

dProfessor,SchoolofAerospace,Xi’anJiaotongUniversity,Xi’an,China,

[email protected]

Traditional blind source separation approaches can only handle determined or

overdetermined blind problems for operational modal identification, where the number of

observed signals is equal to or greater than active modes. When the number of observed

signals is less than active modes, new methods to undertake the underdetermined blind

conditions should be considered. This paper proposes a new modal identification method

basedonanimprovedsparsecomponentanalysis(SCA)todealwiththeunderdetermined

blind source separation problem. Firstly, an improved K-means clustering algorithm with

differentialevolutionalgorithmisintroducedtoestimatemixingmatrix(modalshapesmatrix)

usingsparsecharacteristicsofobservedmixturesignals.Havingestimatedmixingmatrix,the

modalresponsesarerecoveredviathesmoothedzero-norm(SL-0)sparserecoveryalgorithm

fromtheincompleteknowledgeofthemodalshapesmatrixandthesystemoutputresponses

intimeandfrequencydomain.Then,themodalresponsesareconvertedintotimedomainby

inverse short Fourier transform. And the modal frequencies and damping ratios can be

obtainedbyidentificationtechniqueofsingledegree-of-freedom(DOF).Finally,anumerical

simulation on discrete five DOF system shows that whether in determined or

underdetermined conditions, the proposed method can perform accurate and robust

parametersidentificationofstructuraldynamics.



102

A0508-Anapproachforrobustmodelupdatingunderuncertainty

XinjieZhanga,ZhongminDengb

aXueYuanRoadNo.37,Beijing,P.R.China,SchoolofAstronautics,BeihangUniversity,

[email protected]

bXueYuanRoadNo.37,Beijing,P.R.China,SchoolofAstronautics,BeihangUniversity,

[email protected]

Increasinglyattentionhasbeenpouredintouncertaintyofmodelinrecentresearch.However,

thereisstillsomelackofknowledgeaboutrobustnessofmodelupdatingsolution.Considering

uncertaintyattributetofluctuationofdesignvariablesandnon-designvariables,anapproach

forrobustmodelupdatingisproposedinthispapertofindarobustmodelupdatingsolution.

Inthispaper,robustnessofthemodelisdefinedasthevarianceofthemodelanalyticalresult

under uncertainty. And in this method, model updating is constructed as a multi-objective

optimization problem: the first objective is the accuracy of the numerical model and the

second objective is the robustness of the model. NSGA-II algorithm is applied to solve this

multi-objectiveoptimizationproblem.Moreover,metamodelbasedonmovingleastsquare

methodisestablishedtoreducethecomputation.Twonumericalexamplesarealsoemployed

toillustratetheefficiencyoftherobustmodelupdatingmethod,andthecomparisonsbetween

robustnessmodelupdatingsolutionandtraditionalmodelupdatingsolutionunderdifferent

uncertainconditionsaremanifestedinthispaper.



103

A0535-Abayesianmethodforjointparameteroptimalestimationbasedonpower

spectraldensity

YongZhanga,Yanzhaob,HuajiangOuyangc,RuijunSund

aDalian,China,DepartmentofEngineeringMechanics,StateKeyLaboratoryofStructural

AnalysisforIndustrialEquipment,DalianUniversityofTechnology,[email protected]

bDalian,China,DepartmentofEngineeringMechanics,StateKeyLaboratoryofStructural

AnalysisforIndustrialEquipment,DalianUniversityofTechnology,[email protected]

cLiverpool,UnitedKingdom,DepartmentofEngineering,UniversityofLiverpool,

[email protected]

dGuangzhou,China,InternationalDepartment,TheAffiliatedHighSchoolofSouthernChina

NormalUniversity,[email protected]

In this paper, A Bayesian method for joint parameter optimal estimation based on power

spectraldensityisproposedandsuccessfullyappliedtotwotypicalkindsofidentificationof

jointuncertainparameters.Aswellknown,it’sdifficulttoidentifytheuncertainparameters

accuratelybasedonfinitemeasuredresponsedatasincetheexistenceofmeasurementnoise

andmodeluncertainty.Takenthedisplacementpowerspectraldensity(PSD)asthemeasured

output,by introducingtheBayesianprobabilitymethod, the formulationof theconditional

probabilitydensityfunctionforjointparametersundermeasuredconditionsisestablished.

AndtheoptimalestimationforjointparameterscanbeobtainedviatheBayesianmaximum

posterior estimate. The proposed method exhibits excellent estimation performance and

soundrobustness.



104

A0801-Joint-stiffnessidentificationoftrussbridgesusinganenhancedwatercycle

optimizationalgorithm

S.H.Mahdavia,ZexingYub,ChaoXuc

aPostdoctoralresearchfellow,SchoolofAstronautics,NorthwesternPolytechnicalUniversity,

Xi’an,China,[email protected]

bMasterstudent,SchoolofAstronautics,NorthwesternPolytechnicalUniversity,Xi’an,China,

[email protected]

cProfessor,SchoolofAstronautics,NorthwesternPolytechnicalUniversity,Xi’an,China,

[email protected]

Thepriorknowledgeonmathematicalmodelgoverningtoframestructureshasasignificant

effect on structural identification results. In addition, the dynamic behavior of frame

structuresisdirectlyrelatedtothejointrigiditiesandaccurateidentificationofthestiffness

ofstructuraljointsplaysanunderlyingroleinachievingthereliableoutcomesinstructural

conditionassessment.Thispaperpresentsarobuststrategyforjoint-stiffnessidentification

oftrussbridgesintime-domainusinganenhancedwatercycleoptimizationalgorithm.Inthat

regard,aconstitutiveformulationisdevelopedformathematicalmodelgoverningsemi-rigid

connections in truss bridges. In the model, the structural connections between frames are

modeledbyxx(asentencetoexplainthejointmodelyouused.)Then,therecentlydeveloped

watercyclealgorithm(WCA)ismodifiedtobeapplicableforjoint-stiffnessidentificationof

such structures in time-domain. For this purpose, an efficient search space reduction

technique is adopted through the optimization approach to enhance the global search

capabilityofWCA.Anexperimentalvalidationstudyiscarriedoutonalaboratoryscaledtruss

bridge. For comparison purpose, the appropriateness of the WCA in joint-stiffness

identification is thoroughly comparedwith another state-of-the-art optimization algorithm

i.e.,particleswarmoptimization(PSO).Itisconcludedthat,thecomputationalefficiencyof

the proposed strategy is significantly higher than that of PSO in dealing with rough initial

estimatesonstructuralparameters. Thisdemonstrates thesuperiorityofWCAstrategy to

handleglobalsearchoverlargedesignspacewithlargenumberofdesignvariables.Itisalso

deducedthat theproposedstrategycouldbesuccessfullyandconfidently implementedfor

damage detection in structural joints with simultaneous identification of structural

parameters. Finally, this research work was financially supported by National Science

Foundation of China NAFC’s research fund for International Young Scientist; Grant No.

51750110509andtheauthorsgreatlyacknowledgethisfinancialsupport.



105

A0923-Dynamicresponseanalysisofstructureswithhybridrandomandinterval

uncertaities

YanlinZhaoa,ZhongminDengb,YongweiHanc

aSchoolofAstronautics,BeihangUniversityBeijingChina,BeihangUniversityBeijing,

[email protected]

bSchoolofAstronautics,BeihangUniversityBeijingChina,BeihangUniversityBeijing,

[email protected]

cSchoolofAstronautics,BeihangUniversityBeijingChina,BeihangUniversityBeijing,

[email protected]

Anoveldynamicanalysisofstructurewithhybriduncertainties(DASHU)isdevelopedforthe

expressionsforthelowerandupperboundsofthemeanvalueandstandarddeviationofthe

dynamicresponse.Withinthisapproach,intervalvariablesareadoptedtoquantifythenon-

probabilistic uncertainty associated with objective limited information. Some other

parametersareconsideredasrandomvariables.Basedonseriesexpansionofrandomand

interval quantities with respect to uncertain parameters, by means of random interval

momentmethodandperturbationtechnique,theproposedmethodevaluatethelowerand

upperbounds,themidpoint,andintervalwidthofthefirst-andsecond-ordermomentsofthe

structureresponsethroughsolvingdeterministicequations.Monte-Carlosimulationsmethod

(MCSM)areimplementedtovalidatethecomputationalresults.Finally,Numericalexamples

are analyzed to illustrate the feasibility and effectiveness of the proposed method. The

influence on the structure response caused by the individual system parameters are also

investigated.



106

MS8: Computational Modeling of Damage and Failure in

Solids and Structures

A0392- Mitigating mesh dependence of stochastic computation of quasibrittle

fracture

Jia-LiangLea

aDepartmentofCivil,Environmental,andGeo-Engineering,UniversityofMinnesota

Failureanddamageofquasibrittlestructuresareoftenaccompaniedbyvariouslocalization

phenomena,whichgiverisetospuriousmeshdependenceoffiniteelement(FE)simulations.

Though extensive efforts have been devoted to developing computational approaches for

suppressingthemeshdependenceissue,theexistingeffortslargelyfocusedondeterministic

analysis. This paper will discuss the mesh dependence issue in stochastic computation of

quasibrittle fracture. I will first present a new probabilistic crack band model, which is

anchoredbyaprobabilistictreatmentofdamageinitiation,localization,andpropagation.This

model regularizes the energy dissipation of a single material element for the transition

betweendamageinitiationandlocalization.Meanwhile,themodelalsotakesintoaccountthe

randomonsetofdamagelocalizationinsidethefiniteelementforthecasewheretheelement

sizeislargerthanthecrackbandwidth.Therandomlocationofthelocalizationbandisrelated

totherandommaterialstrength,whosestatisticsisdescribedbyafiniteweakest-linkmodel.

Thesecondpartofthetalkwilldiscusstheextensionofthemodeltodynamicloading.Tothis

end,arate-dependentfiniteweakest-linkmodel isdevelopedtocapturethecombinedrate

andsizeeffectsonthestrengthdistributionofmaterialelements.Thismodelisvalidatedbya

set of stochastic discrete element simulations of aluminum nitride as a model system. The

presentresultsdemonstratethattherate-dependentfiniteweakest-linkmodelcanprovidean

analyticallinkbetweenthediscreteelementsimulationandcontinuumFEsimulation,which

leadstoapromisingmultiscalestochasticcomputationalframeworkforquasibrittlefracture.



107

A0633-Phase-filedmodelingofhydraulicfracturingintheframeworkofthetheory

ofporousmedia

C.Luoa,W.Ehlersb

aPhDCandidate,InstituteofAppliedMechanics,UniversityofStuttgart,Pfaffenwaldring7,

70569,Stuttgart,[email protected]

bProfessor,InstituteofAppliedMechanics,UniversityofStuttgart,Pfaffenwaldring7,70569,

Stuttgart,[email protected]

Hydraulicfracturingisawidely-usedtechniqueintheexploitationofoilandgasresources.

Modelingtheprocedureneedstodealwiththedynamicfracturinginporousmediawhichis

of interest to a broader community including engineering geology. To address the two

challenging issues arisen from the cracking process and the multi-component aggregate, a

systematicmethodispresentedintheframeworkoftheTheoryofPorousMedia(TPM)with

thephase-fieldmodelembeddedtohandlethecrackinitializationandpropagation.TheTPM

offerseachconstituentoftheporousmediumwithanindividualmotionfunctionandhence

individual set of balance equation, and describes the coupling, i.e., the transfer of mass,

momentumandenergybetweentheindividualcomponents,usingtheso-calledproduction

terms.Thisfeaturewhencombinedwiththephase-fieldapproachallowsforthetransitionof

theDarcy-typeflowinthesaturatedporousmediadomaintowardstheNavier-Stokes-type

flowinfracturedzones.Tofurtherconsiderpre-existingclosedfracturesorfracturesclosing

aftergeneration,whereeitheronlytheDarcy-typeflowoccursorwheretheNavier-Stokes-

typeflowturnsbacktotheDarcy-typeflow,acrack-openingindicatorisproposedtoresolve

theconflictbetweenthetwo-wayflowtransitionprocessandthemonotonicevolutionofthe

phase-fieldvariable.Theestablishedmethodisthendemonstratedbynumericalresultsof2-

D and 3-D examples. The numerical results have also been compared with experimental

observationsintheliteraturewheregoodagreementisfound.



108

A0757-Crackingelementsmethodforsimulatingmultiplecracks

Yiming.Zhanga,Xiaoying.Zhuangb,c

aSchoolofCivilandTransportationEngineering,HebeiUniversityofTechnology,Tianjin,

300401,China,[email protected]

bDepartmentofGeotechnicalEngineering,TongjiUniversity,Shanghai,China,

[email protected]

cInstituteofContinuumMechanics,LeibnizUniversitätHannover,Hannover,Germany

TheCrackingElementsMethod(CEM)isarecentlyproposednovelapproachfornumerically

simulatingquasi-brittlefracture.CEisbuiltintheframeworkofFiniteElementMethod(FEM),

which does not need remeshing, cover algorism, nodal enrichment or any specific crack

trackingstrategies.Themethodisinspiredbythestaticallyoptimalsymmetricformulation

of the strong discontinuity embedded approach (SDA-SOS) and use the standard Galerkin

method, greatly reducing the coding effort. In CE, the crack paths are represented by

disconnected cracking segments inside the cracked elements. No explicit or implicit

descriptions of the crack’s topology are needed, making the cracks as the solutions of the

considered problems but not parts of it. Comparisons of the CE’s results and the results

obtainedbysomeothermethodssuchasXFEMindicatetheeffectivenessandrobustnessof

theCEmethods,whichiscapableofsimulatingmultiplecomplexfracturepatternsandcracks.



109

A0811-Stochasticanalysisofpolymercompositesrupturesatlargedeformations

modeledbyaphasefieldmethod

JieWua,ColinMcAuliffeb,HaimWaismanc,GeorgeDeodatisd

aCollegeofCivilEngineering,HebeiUniversityofTechnology,Tianjin,China,[email protected]

bDepartmentofCivilEngineeringandEngineeringMechanics,ColumbiaUniversity.NewYork,US

cDepartmentofCivilEngineeringandEngineeringMechanics,ColumbiaUniversity.NewYork,US

dDepartmentofCivilEngineeringandEngineeringMechanics,ColumbiaUniversity.NewYork,US

Carbonblackreinforcednaturalrubberisacompositematerialthatisincreasinglybeingused

inengineeringapplications.Detailedknowledgeoftherelationshipbetweenthecomposition

ofreinforcedrubberanditsfracturetoughnessisimportantforanalysisanddesignofvarious

engineeringsystems.Tothisend,theArruda-Boycemodelisadoptedformodelingthehyper-

elasticrubbermatrixandaNeo-Hookeanmodelisusedforthereinforcingparticles.Aphase

fieldmethodisthenemployedtosimulatedamagenucleationandpropagationunderquasi-

staticloading.Thephasefieldhyper-elasticmodelisvalidatedonasetofexperimentaldata

availableintheliterature.Toquantifytheuncertaintyinthefailureofthesematerials,aMonte

Carlosimulationiscarriedoutwithrandomellipsoidalparticlesdistribution.Eachrealization

undergoeslargestretchinguptofailure,whereforcedisplacementcurvesandfracturesurface

energiesarerecorded.Failureofasampleisdefinedasthepointwheretheloaddropstothe

75%ofthepeakforce.Numericalexamplesofstiffinclusionsandvoidsareconsideredand

the composite response is examined on an intact and pre-notched unit cells. A rigorous

stochastic analysis reveals the statistical distributions corresponding to the rupture of

polymercompositesandprovidesinsightintobetterdesignofthesematerials.

Figure1Stretchandruptureofapolymercompositeatlargedeformation



110

MS9: Reliability Analysis of Engineering Structures

under Disastrous Excitations

A0022-Aprobabilisticanalysisofaphenomenologicalmodelforstructuralcollapse

simulation

ChengChena,b,YifengXuc

aSchoolofEngineering,SanFranciscoStateUniversity,SanFrancisco,CA94132

[email protected]

bSchoolofCivilEngineering,ShandongUniversity,Jinan,Shandong,China

cSchoolofEngineering,SanFranciscoStateUniversity,SanFrancisco,CA94132

The modified IMK model provides a powerful phenomenological model for collapse

simulationofstructuresbyreproducingnonlinearstiffnessandstrengthdegradationinthe

elementsduetorepeatedcyclesofloading.Theaccuracyofcollapsesimulationdependson

realisticcharacterizationofmodelparameters.Modelparametersderivedfromexperiments

however have inherent uncertainties due to optimization. Collapse simulation based on

deterministicparametervaluesofthemodifiedIMKmodelmightnotprovidereliableestimate

ofriskforcollapseduetotheseparameteruncertainties.Inthisstudy,themodifiedIMKmodel

is evaluated through probabilistically characterizing the model parameters based on three

quasi-staticcyclictestsoffull-scalebeam-columnconnectionsconductedpreviouslyatLehigh

University. The Metropolis-Hasting algorithm is utilized to derive the statistics of model

parametersandcomparewiththeirdeterministicvalues.Computationalsimulationsarethen

conductedtoevaluatetheeffectofmodeuncertaintyintermsofenergydissipation.



111

A0347-Simulationofstationarynon-gaussianvectorprocesswithinwave-passage

effectbasedonspectralrepresentationmethod

YongxinWua

aAssociateProfessor,KeyLaboratoryofMinistryofEducationforGeomechanicsand

EmbankmentEngineering,HohaiUniversity,No.1,XikangRoad,Nanjing,China,

[email protected],

Wave-passageeffectisalwaysofgreatimportancewhenperformingthedynamicanalysisof

lagerscalestructures.ThiseffectcanbeeasilyconsideredinthesimulationofGaussianvector

process,butthereisnotanefficientwaytointroduceitintothenon-Gaussianvectorprocess.

Inthispaper,amethodisproposedtogeneratestationarynon-Gaussianvectorprocesswithin

wave-passage effect. In the simulation of vector process, wave-passage effect leads to a

complex-definedcrossspectraldensitymatrix(CSDM).Toseparatethephasepartfromthe

CSDM,animprovedformofspectralrepresentationmethod(SRM)isproposed,inwhichthe

phasepartrepresentingthewave-passageeffectcanbedirectlyexpressedinanexplicitform

in the simulation formula. Then the characteristic of phase part representing the wave-

passage effect during the nonlinear translation (translating underlying Gaussian vector

processtotheprescribednon-Gaussianvectorprocess)is investigated.It isfoundthat,the

phase part is not changed. Based on this good feature, the modified SRM and the iterative

schemecanbecombinedtosimulatenon-Gaussianvectorprocesswithinwave-passageeffect.

Two examples, involving the simulation of seismic ground motions and wind velocity time

histories,arepresentedtoshowthegoodfeatureaswellasthecharacteristicsofthesimulated

vectorprocess.



112

A0349- Stochastic dynamic response analysis and reliability assessment of non-

linearstructuresunderfullynon-stationarygroundmotions

JunXua,De-chengFengb

aAssociateprofessor,CollegeofCivilEngineering,HunanUniversity,Changsha,P.R.China,

[email protected]

bAssistantprofessor,KeyLaboratoryofConcreteandPrestressedConcreteStructuresofthe

MinistryofEducation,SoutheastUniversity,2Sipailou,Nanjing210096,China

In this paper, stochastic dynamic response analysis and reliability assessment of nonlinear

structuresunderfullynon-stationarygroundmotionsisinvestigatedbasedontheprobability

density evolution method (PDEM). To handle this problem, a new method is proposed for

pointsselectioninhigh-dimensionalrandom-variatespaceforPDEM,whichisofparamount

importance for the tradeoff of accuracy and efficiency. First, the original high-dimensional

space is decomposed into several two-dimensional orthogonal subspaces. Then, each

subspace is partitioned via the Voronoi cells and the representative points and assigned

probabilitiesineachsubspacearespecifiedaccordingly.Finally,therepresentativepointsand

assignedprobabilitiesineachsubspacearerandomlypairedtoformulatetherepresentative

pointsandassignedprobabilitiesinhigh-dimension.Numericalexampleisstudiedtovalidate

theproposedmethod,whichindicatesthattheproposedmethodisofefficiencyandaccuracy

forhigh-dimensionalstochasticdynamicproblemofstructures.Problemneedstobefurther

investigatedisalsopointedout.



113

A0403- Integrated reliability-based optimization of civil structure and vibration

controlsystemsusingimprovedgeneticalgorithms

ZhenMeia,HaifengWangb

aLecturer,HuaqiaoUniversity,[email protected]

bLecturer,HuaqiaoUniversity,[email protected]

Disastrousexcitationssuchassevereearthquakesandstrongwindsposeagreatthreattocivil

engineering structures. To improve the safety and serviceability of structures excited by

external dynamic loads, significant efforts have been devoted to the investigations on

structuralvibrationcontrol.Variouscontrolstrategies,includingpassive,active,semi-active

and hybrid control systems, have been proposed and many control devices, like rubber

bearings, buckling constraint supports, magnetorheological dampers and so on, have been

developedandappliedtocivilstructures.Ithasbeenproventhatactive/semi-activecontrol

effectsaresimultaneouslyrelatedtoinputdynamicactions,controlalgorithms,thenumber

and location of actuators / dampers and physical parameters of controlled structures.

Therefore,itisnecessarytoconducttheoptimizationofthecontrolsystemandthecontrolled

structure as a whole. In this paper, an improved genetic algorithm is developed to solve

reliability-basedoptimizationproblemsforcivilstructureandactivecontrolsystems,inwhich

thenumberandpositionofactuators,thecontrolalgorithm,thestructureparameterandthe

randomness of seismic excitations are taken into account synchronously. The optimization

objectivefunctionisthefailureprobabilityofthecontrolledstructureandthefirstexcursion

failure criterion is used in dynamic reliability analysis. Moreover, the reliability of the

controlledstructureisdefinedbyinter-storydriftanglesandisperformedusingthetheoryof

extreme value distribution and the probability density evolution method. In addition, a

selection policy, which is a combination of random competition and elitist strategy, an

improvedbinarysingle-pointcrossoverandanimprovedsingle-locusortwo-locusmutation

are adopted in the developed genetic algorithm. Results of numerical examples conducted

using MATLAB software show that the proposed algorithm has the advantages of high

precisionandfastconvergence,thusitisaneffectiveintegratedoptimizationmethodforcivil

structureandvibrationcontrolsystems.



114

A0520-Seismicfragilityanalysisofurbanroadnetwork:acasestudyontangshan

city

DingWanga

aAssociateprofessor,YanshanUniversity,[email protected]

Recently, many studies have analyzed the vulnerability of the components of the roadway

transportationsystem,suchasembankment,cut,slopeandroadpavement,underearthquake

attack. However, the seismic fragility analysis of the roadway network has not been fully

investigatedorappliedinengineeringpractice.Inthisstudy,aframeworkforanalyzingthe

seismic fragility of the urban roadway network is presented and used for the roadway

transportation system in Tangshan City, China. This approach is based on the Monte-Carlo

method.Thespatialvariationoftheseismicgroundmotionsisconsidered.Bytheproposed

approach, the seismic performances of the roadway network under earthquake attacks of

differentintensityispresentedanddiscussed.Thepresentstudyshowsthat,forTangshanCity,

theconnectivityoftheurbanroadwaynetworkcanbewellmaintainedwhentheaveragepeak

groundacceleration(PGA)ofthespatiallyvariableseismicgroundmotionsislessthan0.25g.

ThepresentworkalsoadvocatesthatwhenthePGAislargerthan0.55gthegiantcomponent

oftheroadwaynetworkisdamagedandtheroadwaytransportationsystemtotallylossesits

functionality.



115

A0538- Impact of initial damage path and spectral shape on aftershock collapse

fragilityofRCframes

Xiao-HuiYua,Da-GangLub,Fu-ZiMac

aSchoolofCivilEngineering,HarbinInstituteofTechnology,Harbin,P.R.China,

[email protected]

bSchoolofCivilEngineering,HarbinInstituteofTechnology,Harbin,P.R.China,

[email protected]

cSchoolofCivilEngineering,HarbinInstituteofTechnology,Harbin,P.R.China,

[email protected]

Theinfluencesofinitialdamagepathsandaftershock(AS)spectralshapeontheassessment

ofAScollapsefragilityareinvestigated.Todothis,afour-storyductilereinforcedconcrete(RC)

framestructureisemployedasthestudycase.Thefar-fieldearthquakerecordsrecommended

by FEMA P695 are used as AS ground motions. The AS incremental dynamic analyses are

performedforthedamagedstructure.Toexaminetheeffectofinitialdamagepaths,atotalof

sixkindsofinitialdamagepathsareadoptedtosimulatedifferentinitialdamagestatesofthe

structurebypushoveranalysisanddynamicanalysis.Forthepushover-basedinitialdamage

paths, the structure is “pushed” using either uniform or triangle lateral load pattern to a

specifieddamagestatequantifiedbythemaximuminter-storydriftratio.Amongthedynamic

initialdamagepaths,onesinglemainshockgroundmotionorasuiteofmainshockground

motionsareusedintheincrementaldynamicanalysestogenerateaspecifiedinitialdamage

statetothestructure.Theresultsshowthatthestructurecollapsecapacityisreducedasthe

increase of initial damage, and the initial damage paths show a significant effect on the

calculatedcollapsecapacitiesofthedamagedstructure(especiallyatseveredamagestates).

To account for the effect of AS spectral shape, the AS collapse fragility can be adjusted at

differenttargetvaluesofεbyusingthelinearcorrelationmodelbetweenthecollapsecapacity

(intermofspectralintensity)andtheASεvalues,andcoefficientsofthislinearmodelisfound

tobeassociatedwiththeinitialdamagestates.



116

A0563-Structuralreliabilityanalysisusinguqfemsoftware

ZiqiWanga,SanjayGovindjeeb,NikhilPadhyec,FrankMcKennad

aAssistantProfessor,GuangzhouUniversity,[email protected]

bProfessor,UniversityofCalifornia,Berkeley,[email protected]

cPostdoctoralResearcher,UniversityofCalifornia,Berkeley,[email protected]

dSeniorScientist,UniversityofCalifornia,Berkeley,[email protected]

In this talk, we will illustrate the usage of uqFEM, a software for driving uncertainty

quantification in finite element and other analysis programs, with special emphasis on

structural reliability applications. Recently developed by SimCenter

(https://simcenter.designsafe-ci.org/)atUniversityofCalifornia,Berkeley,uqFEMisanopen

source software tool that allows engineers to perform reliability-based computations for

naturalhazardsandriskassessment.Inthetalktheusabilityandcapabilitiesoftherelease

version of uqFEM will be illustrated with numerical examples on benchmark structural

reliabilityproblemsincludingtaildistributionestimation.Toconcludethetalk,newfeatures

anduncertaintyquantificationalgorithmsplannedforfuturereleaseswillbediscussed.



117

A0577- Seismic reliability analysis of energy-dissipation bridge structures using

HamiltonianMonteCarlobasedsubsetsimulationinconjunctionwithexplicittime

domaindimensionalityreduction

HaitaoMaa,ShaominJiab,ZiqiWangc,WeimingChend

aEarthquakeEngineeringResearch&TestCenter,GuangzhouUniversity,Guangzhou,China

bEarthquakeEngineeringResearch&TestCenter,GuangzhouUniversity,Guangzhou,China

cEarthquakeEngineeringResearch&TestCenter,GuangzhouUniversity,Guangzhou,China

dEarthquakeEngineeringResearch&TestCenter,GuangzhouUniversity,Guangzhou,China

The seismic reliability analysis of energy-dissipation bridge structures is typically a local

nonlinearproblem,sinceenergydissipationdevicesareofteninstalledinspecificlocationsof

abridgestructure.TheMonteCarlosimulation(MCS)methodhastheapplicabilitytosolve

genericnon-linearreliabilityproblems,yetthecomputationalcostofMCSisoftentoohighfor

engineeringpractice.ThecomputationalefficiencyofusingMCStoperformseismicreliability

analysisisdeterminedbytheefficiencyofthespecificMCSschemeaswellastheefficiencyof

asinglerunofdeterministicnonlinearstructuraldynamicanalysis.Thepaperproposesan

efficientcomputationalmethodforseismicreliabilityanalysisofenergy-dissipationbridges

via the usage of: a) Hamilto-nian Monte Carlo based subset simulation to improve the

sampling efficiency, and b) an explicit time domain dimensionality reduction technique to

improve the efficiency of deterministic struc-tural dynamic analysis of local nonlinear

problems.Numericalexamplesofbridgemodelsareinvestigatedtoillustratetheefficiencyof

theproposedapproach.



118

A0824-Assessingthespallingoftunnelliningssubjectedtofireloading

Yiming.Zhanga,Matthias.Zeimlb,Marcus.Maierc,Yong.Yuand,Roman.Lacknere

aSchoolofCivilandTransportationEngineering,HebeiUniversityofTechnology,Xiping

Road5340,300401Tianjin,China,e-mailaddress:[email protected]

bMaterial-TechnologyInnsbruck(MTI),UniversityofInnsbruck,Technikerstraße13,6020

Innsbruck,Austria

cMaterial-TechnologyInnsbruck(MTI),UniversityofInnsbruck,Technikerstraße13,6020

Innsbruck,Austria

dDepartmentofGeotechnicalEngineering,TongjiUniversity,SipingRoad1239,200092

Shanghai,China

eMaterial-TechnologyInnsbruck(MTI),UniversityofInnsbruck,Technikerstraße13,6020

Innsbruck,Austria

Spallingistheviolentsplittingofconcretepiecesfromthefire-loadedsurface,whichgreatly

jeopardizes the integrity of the structures. Fires in tunnels commonly lead to a fast

temperatureincreaseduringthefirstminutesofthefirewithamaximumtemperatureover

1200°C,potentiallyresultingintoseriousspalling.Bydevelopingandapplyingafullycoupled

thermo-hydro-chemo-mechanicalmodel,wefirstlyanalyzethespallingoffireloadedplate-

likestructures.Then,weestablishafastassessingprocedureforquicklyevaluatingspalling

riskoftunnelliningswithdifferentconcretetypesandenvironmentalmoisturesandpropose

criterion for grading the spalling risk. Comparisons between the obtained results and

experimental results prove the effectiveness of our methods, which can be used by the

engineersanddesignerforassessingthefirespallingriskofconstructedandplanedtunnel

structures.



119

MS10: Damage and Fracture of Brittle and Quasi-Brittle

Materials

A0034- Influenceofasphaltmixture typeonstrengthsizeeffectstatisticsat low

temperature

AugustoCannoneFalchettoa

aAssistantProfessor,DepartmentofCivilEngineeringandEnvironmentalScience,

TechnischeUniversitätBraunschweig,Germany,[email protected]

Low temperature cracking represents a deleterious phenomenon for asphalt pavement

experiencingcoldclimates.Hence,accurateevaluationofstrengthandfracturepropertiesof

asphaltmixturesiscriticalforensuringthedurabilityoftheentirepavementstructure.Itwas

recentlydemonstratedthat,at lowtemperature,asphaltmixturesbehaveasaquasi-brittle

materialand,consequently, itsnominalstrengthstronglydependsonstructuresize.Inthis

paper,acomprehensiveexperimentalstudyisconductedtoevaluatetheeffectofmixturetype

onthescalinglawforquasi-brittlestrength.Astandardasphaltmixtureforwearingcourse

andaStoneMasticAsphalt(SMA)areselectedforthispurpose.Three-pointbendingtestsare

performedonunnotchedasphaltmixturebeamsoffourdifferentsizesat lowtemperature.

ThestrengthvaluesareevaluatedbasedontheWeakestLinkModel(WLM)incombination

withthewell-knownTypeIenergetic-statisticalsizeeffectlaw(SEL).Asignificantvariation

intheevolutionoftheSELisobservedwithadramaticdecreaseinstrengthoversize.The

effect of mixture type indicates a significant influence on the statistics of strength with an

increase of the grafting point in the cumulative distribution function of the representative

volume element (RVE) for SMA. This is linked to an increased brittleness, which is overall

compensatedbythemodifiedbinderusedforthisspecificmixtureandbythehighermaterial

strength. The experimental and modeling results clearly demonstrate the importance of

understanding the scaling evolution of asphalt mixture strength since this parameter is

commonlyusedasinputforpavementdesignpurposes.



120

A0857-Modellingofdamageandfractureofplainweaveceramicmatrixcomposites

underuni-aixaltension

DaxuZhanga,MingmingChenb,HailongLiuc,YunhaoZhangd

aAssociateProfessor,SchoolofNavalArchitecture,OceanandCivilEngineering,Shanghai

JiaoTongUniversity,China,[email protected]

bPhDCandidate,SchoolofNavalArchitecture,OceanandCivilEngineering,ShanghaiJiao

TongUniversity,China,[email protected]

cMScCandidate,SchoolofNavalArchitecture,OceanandCivilEngineering,ShanghaiJiao


dMScCandidate,SchoolofNavalArchitecture,OceanandCivilEngineering,ShanghaiJiao


Ceramicmatrixcomposites(CMCs)havethecharactersoflowdensity,highmodulusandgood

thermalstability.Overthepastdecades,greateffortshavebeenmadetostudythemechanical

behaviourofCMCs.Amongthem,ZhangandHayhurst(2010)[DaxuZhang,HayhurstDR.,

2010. Stress-strain and Fracture Behaviour of 0°/90° and Plain Weave Ceramic Matrix

CompositesfromTowMulti-axialProperties.InternationalJournalofSolidsandStructures.

47(21).2958-2969.]employedahomogenisedfiniteelementmodeltostudystress-strainand

fracturebehaviourofcross-plyandwovenCMCs.Onthebasisofthiswork,anon-linearmulti-

scalemodelhasbeendevelopedtopredictstress-strainresponseofplainweaveCMCsunder

in-planeloading.Acontinuumdamagestateparameterdeterminedbytheratiooffailedfibres

and total fibres was used to evaluate the longitudinal tensile behaviour of a unidirectional

fibre-reinforcedCMCtow.Theseanalyticalresultsoffibretowswerethenemployedbyafinite

elementplainweaveCMCunitcellmodelasthematerialproperties,inwhichthetensileand

shearpropertiesof towswerenonlinearandweredefinedbyauserdefinedsubroutine in

Abaqus.APythonscriptwasdevelopedtodefinetheperiodicboundaryconditionsoftheunit

cell. The uni-axial tensile stress-strain response has been predicted using the multi-scale

model. The fidelity of the model has been verified by comparing its predictions with the

experimentalresults.



121

A0863-Predictionofsheardamagebehaviourof fibre-reinforcedceramicmatrix

tows

DaxuZhanga,QianXub,YunhaoZhangc,HailongLiud

aAssociateProfessor,SchoolofNavalArchitecture,OceanandCivilEngineering,Shanghai

JiaoTongUniversity,China,[email protected]

bResearchAssistant,SchoolofNavalArchitecture,OceanandCivilEngineering,ShanghaiJiao


cMScCandidate,SchoolofNavalArchitecture,OceanandCivilEngineering,ShanghaiJiao


dMScCandidate,SchoolofNavalArchitecture,OceanandCivilEngineering,ShanghaiJiao


Ceramicmatrixcomposites(CMCs)havethecharactersoflowdensity,highmodulusandgood

thermalstability.Overthepastdecades,greateffortshavebeenmadetostudythemechanical

behaviourofCMCs.However,arigorousframeforunderstandingnonlinearshearbehaviorof

CMCs on both microscopic and macroscopic level is lacking. Nevertheless, it is generally

acceptedthatmatrixcrackingisthemaindamagemechanismwhichgovernstheshearstress-

strainresponseofCMCs. In thispaper,amodelbasedonasinglecontinuumdamagestate

parameterdeterminedbytheratioofthecurrentmatrixcrackdensityandsaturateddensity,

hasbeendevelopedtopredicttheshearbehaviourofaunidirectionalfibre-reinforcedceramic

matrix composite (CMC) tow. The model considers the influence of matrix cracking using

Weibull distributions of damaged matrix shear strength. The nonlinear shear stress-strain

response of a CMC tow, predicted by the damage model, has been used in a macro-scale

analysistoevaluateitsfidelity.



122

A0866- Validation of the combined fem-dem on mode i and ii concrete rupture

subjectstosemi-circularbending

XudongChena

aLecturer,SuzhouUniversityofScienceandTechnology,[email protected]

Tovalidatetheeffectivenessof thecombinedFEM-DEMundercomplex loadingconditions,

simulationsareperformedandresultsarecomparedwithknownsemi-circularbending(SCB)

tests based on concrete aggregate specimen with pre-existing notches. A bilinear strain-

softeningcurvewhichisimplementedintoacohesivefracturemodelisadoptedtodepictthe

behavior from continua to discontinua. A constant displacement rate is applied to the top

center of the specimen. By comparing the simulation results from the FEM-DEM and the

experimentaldatafromknownSCBtests,conclusionsarereachedthatthecombinedFEM-

DEMtogetherwiththecohesivefracturemodelcanpredictbothMode-IandII failurewith

goodaccuracy.ForMode-Ifracture,adominantflexuralcrackisobtainedfromthenotchtip

uptotheloadingpoint.Ontheotherhand,anobliquecrackisformedforMode-IIfracture,

approximatelylinkingtheloadingpointandthenotch.Ingeneral,thecombinedFEM-DEMis

applicableofsimulatingModeIandIIfractureofconcreteSCBspecimen.



123

A0978-Impactfracturesimulationofmonolithicandlaminatedglassusinghybrid

discontinuaandcontinuamethod

Xing-erWanga,JianYangb

aPostdoc,DepartmentofCivilEngineering,ShanghaiJiaoTongUniversity

[email protected]

bProfessor,DepartmentofCivilEngineering,ShanghaiJiaoTongUniversity,

[email protected]

Thisworkpresentsacomparativestudyontheavailablenumericalapproachesformodelling

thefracturingofbrittlematerials,e.g.glassandrock.Thesemodellingtechniquesincludefour

popularnumericalmethodssuchasthefiniteelementmethod(FEM),extendedfiniteelement

method (XFEM), discrete element method (DEM) and combined finite-discrete element

method (FEM/DEM). This study investigates their inherent weaknesses and strengths for

modelling the fracture and fragmentation process both in static and dynamic problem. A

comparativereviewisfirstcarriedouttoillustratetheirfundamentalprinciplesaswellasthe

advantages for the modelling of cracks, followed by state-of-the-art trial application in the

example cases. Several examples of a glass beam subjected to low velocity impact are

examinedusingaforementionednumericalmethodsasaplanestressproblem.Byevaluating

their applicability, the most feasible model, i.e., FEM/DEM, for the entire dynamic fracture

response is identified. It is further examined comparing with the experimental results for

modellingthehighspeedandobliqueimpacttestsonglasssurface.Throughsuchcomparative

study, the FEM/DEM exhibits the most satisfactory results when modelling the dynamic

fracture of brittle materials with specific reference to glass. It also shows potential in

simulatingthecompositeactionbetweenductileinterlayerandbrittleglassinthelaminated

glass.TheMooney-RivlinmodelforthehyperelasticityofthePVBinterlayersaswellasthe

improvedXuandNeedlemanmodelservingasthemixed-modeinterfacialconstitutivelaw,in

particular, describing the combined damage-plasticity behaviour for irreversible unloading

arethenimplementedintoFEMDEM.Theimpactdamageoflaminatedglassin2Dproblem

including the interlaminardelaminationandcrackpattern is thenexaminedby using such

integratedapproachesThecomparisonbetweenthesimulationandtheexperimentalresults

for several laminated glass make-ups shows that this interfacial model can adequately

reproduce the typical delamination behaviour. The characteristics of the stress wave

propagationandtheinterlayertearingintheexamplecasescanbesatisfactorilyreproduced.

Theshortcomingofthediscretecrackmodelinmodellingtheimpactdamageofstrengthened

glass and the resulting errors are discussed as well. Several potential solutions for such

shortcomingsarefinallypresented.



124

MS12: Dynamic Analysis and Seismic Performance of

Structures under Strong Earthquake Ground Motions

A0008- Potential risks on using disconnected composite foundation systems in

activeseismiczones

MohamedElmasrya,AhmedRaghebb,TareqMostafac,MohamedGhazyd

aProfessor,ArabAcademyforScience,Technology&MaritimeTransport,[email protected]

bAssociateDoctor,ArabAcademyforScience,Technology&MaritimeTransport,

[email protected]

cAssociateDoctor,ArabAcademyforScience,Technology&MaritimeTransport,

[email protected]

dTeachingAssistant,ArabAcademyforScience,Technology&MaritimeTransport,

[email protected]

Choosingthesuitableinfrastructuresystemisbecomingmorechallengingwiththeincrease

indemandforheavierstructurescontemporarily.Thisisthecasewherepiledraftfoundations

have been widely used around the world to support heavy structures without extensive

settlement.Inthelattersystem,pilesarerigidlyconnectedtotheraft,andmostoftheload

goestothesoillayeronwhichthepilesarebearing.Inspiteofthat,whensoilprofilescontain

thickersoftclaylayersnearthesurface,oratrelativelyshallowdepths,itisunfavourableto

usetherigidpiledraftfoundationsystem.Consequently,thedisconnectedpiledraftsystem

wasintroducedasanalternativeapproachfortherigidlyconnectedsystem.Inthissystem,

pilesaredisconnectedfromtheraftusingacushionofsoil,mostlyofagranularinterlayer.The

cushionisusedtoredistributethestressesamongthepilesandthesubsoil.Pilesarealsoused

tostiffenthesubsoil,andbythiswayreducethesettlementwithoutbeingrigidlyconnected

to the raft. However, the seismic loading effect on such disconnected foundation systems

remainsaproblem,sincethesoilprofilesmayincludethickclaylayerswhichraiserisksof

amplificationofthedynamicearthquakeloads.Inthispaper,theeffectsofseismicbehavior

ontheconnectedanddisconnectedpiledraftsystemsarestudiedthroughanumericalmodel

using Midas GTS NX Software. The study concerns the soil-structure interaction and the

expectedbehaviorofthesystems.AdvantagesandDisadvantagesofeachfoundationapproach

arestudiedandacomparisonbetweentheresultsarepresentedtoshowtheeffectsofusing

disconnected piled raft systems in highly seismic zones. This was done by showing the

excitationamplificationineachofthefoundationsystems.



125

A0016-Output-onlyidentificationofcivilengineeringsystems

ErtugrulTaciroglua,S.FaridGhaharib

aProfessor,CivilandEnvironmentalEngineeringDepartment,UCLA,USA,[email protected]

dPostdoctoralResearchAssociate,CivilandEnvironmentalEngineeringDepartment,UCLA,

USA,[email protected]

Formechanicalsystemsandlaboratory-scalestructures,itisusuallypossibletoarrangeand

carry out dynamic tests. Typically, the same is not possible for full-scale civil engineering

systems (bridges, buildings, dams, tunnels, geotechnical arrays, etc.). As such, responses

measured during natural events (earthquakes, hurricanes, etc.) provide the only means to

examinestructuralresponsesinthemostrealisticmannerpossible.Theseexaminationshave

multiple utilities, ranging from the development and validation of predictive models—

including the characterization of uncertain loads—to health and performance monitoring.

However,thesenaturallygeneratedexcitationsarerarelymeasurable,renderingtherequisite

identificationproblemstobeill-posedforwhichboththesystemandtheinputexcitationsare

unknown. For example, a building (or bridge) under its operational condition is usually

persistently excited by ambient loads that are not measurable (like micro-tremors, ocean

waves, people, car traffic, etc.). Or, it is not possible to record true seismic excitations to a

buildingstructure,becauseeventhemotionsrecordedatthefoundationlevelarenotpurely

input,duetoinertialeffects.Althoughvariousoutput-onlysystemidentificationmethodshave

been developed during the past few decades, they mostly adopt various simplifying

assumptionsregardingthestatisticalcharacteristicsoftheunknowninputexcitations—the

primaryassumptionbeingthestationarityoftheunknowninput.Nevertheless,mostreal-life

casesdonotfallintothissimplification,andthustheidentifieddynamiccharacteristicscan

have large errors. Over the past decade, the authors have been working towards the

development of novel and robust output-only techniques to resolve deficiencies associated

with these traditional output-only methods. In this paper, a comprehensive survey of their

methods—ranging from model-free Blind Modal Identification (BMID) methods to model-

basedBayesianfilteringtechniques—arepresented,alongwiththeapplicationofthesenew

techniquestoreal-lifeengineeringproblems.



126

A0024-Analysisofthebridgewithsinglecolumnbyperformanceandreliability-

basedseismicdesignmethod

XiangYiqianga,LuoXiaofengb

aProf.,DepartmentofCivilEngineering,ZhejiangUniversity,[email protected]

bAssociatedProf.,SchoolofCivilEngineeringandArchitecture,ZhejiangIndustry

PolytechnicCollege,[email protected]

Theprobabilitylimitstatedesignmethodbasedonreliabilityisoneofthestructuraldesign’s

basicprinciples,Anewgenerationstructuralseismicdesignmustbasedonperformance,it

shouldconsidertheinfluenceofrandomfactors.Combiningwiththeabovetwoaspects,this

paperstudiestheseismicreliabilityanalysismethodforthebridgeswithsinglecolumnunder

differentseismicfortificationlevelsbasedonperformanceandreliability.Thekeypointsand

flow chart of theoretical analysis methods of seismic reliability under different seismic

fortification levels are described and given. Taking the bridges with single column as an

example, thethree-dimensionalspacemodel isestablishedbyOpenseesplatform.Thepier

and the whole bridge system’s reliability are analyzed under different seismic inputs and

performancelevelsbyProbabilityPushoverMethod(PPM).Comparedwiththevaluesgained

byusingnonlinearStochasticFiniteElementMethod(SFEM),theresultsshowthatthefailure

probability values gained by using nonlinear SFEM and PPM are basically identical, bridge

system’sfailureprobabilityisgreaterthanasinglecomponent’sfailureprobabilityunderthe

actionofearthquake.Itcanbewidelyusedinbridge'sseismicdesign.



127

A0105- Dimensional seismic responses of shear-flexural beam and self-similar

interstorydriftspectrum

GuiqiangGuoa,DixiongYangb

aPhDstudent,DepartmentofEngineeringMechanics,DalianUniversityofTechnology,State

KeyLaboratoryofStructuralAnalysisforIndustrialEquipment,Dalian,China,

[email protected]

dProfessor,DepartmentofEngineeringMechanics,DalianUniversityofTechnology,StateKey

LaboratoryofStructuralAnalysisforIndustrialEquipment,Dalian,China,

[email protected]

This paper investigates the influence of stiffness reduction along height on the seismic

responses of shear-flexural beams subjected to near-fault ground motions by using

dimensionalanalysistheory,andproposesaregressionmodelfortheself-similarinterstory

drift spectrum and self-similar floor acceleration spectrum. The stiffness along structural

height is always nonuniformly distributed in realistic buildings, which is not sufficiently

consideredintheseismicresponseanalysisofshear-flexuralbeamssubjectedtonear-fault

ground motions. This paper systematically analyzes the dimensional seismic responses of

shear-flexuralbeamswithnonuniformstiffnessalongheight,whereinbothanalyticalpulses

andrealisticgroundmotionsareconsidered.Thenormalizedresponsesareself-similartothe

pulseamplitudeandnormalizedstructuralheight.Itisshownthattheself-similarinterstory

drift spectrum is affected by the lateral stiffness ratio of top to base end of shear-flexural

beams.Incontrast,theself-similarflooraccelerationspectrumisalmostnotinfluencedbythe

lateralstiffnessratiooftoptobaseendofshear-flexuralbeams.However,theeffectofstiffness

reductionisgenerallysmallandhencecanbeneglectedinthepreliminarydesignofbuildings.

Aproposedregressionmodelissuitablefortheself-similarinterstorydriftspectrumandself-

similar floor acceleration spectrum, which can predict maximum interstory drift ratio and

maximumflooraccelerationwithacceptableaccuracy.



128

A0109- A new approach to design explicit time integration algorithm with

numericaldissipation

ShiLia,HongjiaZhangb,DixiongYangc

aPhDstudent,DepartmentofEngineeringMechanics,DalianUniversityofTechnology,State

KeyLaboratoryofStructuralAnalysisforIndustrialEquipment,Dalian,China,

[email protected]

bMaster,DepartmentofEngineeringMechanics,DalianUniversityofTechnology,StateKey


[email protected]

cProfessor,DepartmentofEngineeringMechanics,DalianUniversityofTechnology,StateKey


[email protected]

Thepseudodynamictestingandreal-timehybridtestinginearthquakeengineeringrequire

the fast and accurate dynamic analysis of structure. To develop the stable, accurate and

efficienttimeintegrationalgorithmsistheimportantresearchtopic.Thispaperproposesa

familyofexplicittimeintegrationalgorithmsforstructuraldynamicsbyutilizingtheseparate-

designconcept.

Thetraditionaltimeintegrationalgorithmusestheequationofmotionandonesetofrecursive

formulaofvelocityanddisplacementtosolvethedynamicresponseofsystem.However,the

new separate-design approach adopts two sets of recursive formula of velocity and

displacement.Onesetofrecursiveformulaofvelocityanddisplacementiscombinedwithand

the motion equation to obtain the recursive formula of acceleration, and another set of

recursiveformulaofvelocityanddisplacementisutilized.Asaresult,therecursiveformulaof

acceleration,displacementandvelocityareachievedseparately.Theformulationcoefficients

of new algorithm adopt the structure-dependent parameters. The values or ranges of

integration parameters are derived by making constraint conditions to meet the desired

numerical properties. Further, the parameters are function of the spectral radius ρ, which

controlsthenumericaldamping.Theoreticalanalysisindicatesthatthenewproposedexplicit

time integration algorithms possess the properties of second accuracy, self-starting, non-

overshoot behavior for zero-order displacement and zero-order velocity response,

unconditionallystableandcontrollablenumericaldamping.Moreover,theCRalgorithmand

KR-α method are special case of the new explicit algorithms. Finally, numerical examples

demonstrate that the accuracy of new algorithms is superior to that of Generalized-α

algorithms.Theexplicittimeintegrationalgorithmsareappliedtosolvenonlineardynamic

responsesofstructures,whichverifiestheeffectivenessandstabilityofthenewalgorithms.



129

A0112- Recent advances in engineering characteristics of near-fault ground

motionsandseismiceffectsofbuildingstructures

DixiongYanga,GuohaiChenb

aProfessor,DepartmentofEngineeringMechanics,DalianUniversityofTechnology,StateKey


[email protected]

Severedamagesofcivil infrastructuresundernear-faultgroundmotionshave impelledthe

community of earthquake engineering to pay close attention and investigation to their

engineering characteristics and structural seismic effects. This paper reviews the recent

researchadvancesofauthorsintheengineeringcharacteristicsofnear-faultgroundmotions

andseismicresponsesandbase-isolatedperformanceanalysisofbuildingstructures.Firstly,

twonon-structure-specificintensityparameters,suchasimprovedeffectivepeakacceleration

andvelocity(IEPA,IEPV)wereproposed.Twofrequencycontentparametersweresuggested,

namely the mean period of Hilbert marginal spectrum Tmh and coefficient of variance of

dominant instantaneous frequency of Hilbert spectrum Hcov which reflects the frequency

nonstationarydegreeofgroundmotions.Meanwhile,anewstochasticmodel tosynthesize

near-faultimpulsivegroundmotionswiththefeatureofthestrongestpulsewasestablished.

Then, the chaotic and fractal/multifractal characteristics of strong earthquake ground

motions were analyzed deeply to explore their complexity from a novel perspective of

nonlinear dynamics, and the inherent relation between fractal dimensions and period

parameters of near-fault motions was exposed. Moreover, the mechanism of interstory

deformationoftallbuildingwasillustratedbasedontheengineeringpropertiesofimpulsive

ground motions and generalized drift spectral analysis. Dimensional responses analysis of

elastoplastic structures and self-similar response spectrum are presented. Finally, the

influences of ground motion properties on the seismic responses and performance of tall

structuresandbase-isolatedbuildingswererevealed.



130

A0293- Optimal design of sma cable restrainers for seismic protection of a lrb

isolatedsimplysupportedhighwaybridge

ShuaiLia,FarshadHedayatiDezfulib,Jing-quanWangc,M.ShahriaAlamd

aKeyLaboratoryofConcreteandPrestressedConcreteStructuresofMinistryofEducation,

SchoolofCivilEngineering,SoutheastUniversity,Nanjing,Jiangsu,P.R.China

bSchoolofEngineering,TheUniversityofBritishColumbia,Kelowna,BCV1V1V7,Canada

cKeyLaboratoryofConcreteandPrestressedConcreteStructuresofMinistryofEducation,

SchoolofCivilEngineering,SoutheastUniversity,Nanjing,Jiangsu,P.R.China

dSchoolofEngineering,TheUniversityofBritishColumbia,Kelowna,BCV1V1V7,Canada

Isolation bearings have been widely used to improve the seismic performance of highway

bridges. Considering the flexibility of the isolation systems, isolated highway bridges are

susceptible to unseating or even collapse due to excessive displacement under strong

earthquakes.Shapememoryalloy(SMA)wireswithsuperiorenergydissipationcapacityand

self-centering property can be utilized as seismic restrainers to limit the displacement.

However, there is no appropriate design method for SMA restrainers in isolated highway

bridges.TheobjectiveofthisstudyistoevaluatetheseismicperformanceofaLRBisolated

simply supported bridge retrofitted with SMA restrainers. A design procedure for SMA

restrainer is proposed according to a linearized two degree-of-freedom (DOF) analytical

model. The optimal design parameters, i.e. the ratio of the allowable displacement to seat

width(∆a/Lsw),normalizedelongationparameterofSMAcables(α),andhorizontalangle(θ0)

between the restrainer and horizontal level, are determined by conducting full factorial

analysis.Theresultsshowedthattheoptimalvaluesoftheratiooftheallowabledisplacement

toseatwidth(∆a/Lsw),whicheffectivelyreducestherelativedisplacementandsimultaneously

control the base shear of the piers, are between 0.4 and 0.7. The optimum value of the

horizontal angle (θ0) ranges from 0 to π/4. The optimum value of normalized elongation

parameter(α)shouldbe1.0.



131

A0313-Featuresofoffshoreseismicgroundmotionsdistinctfromtheonshore

Q.Zhanga,XiangYuanZhengb

aPhDcandidate,DepartmentofCivilEngineering,TsinghuaUniversity,

[email protected]

bProfessor,DivisionofOceanScienceandTechnology,TsinghuaUniversity,Shenzhen

GraduateSchool,[email protected]

Thefeaturesofoffshoregroundmotionshavenotyetbeenuncoveredthoroughlyforlacking

seafloor measured data. This study managed to collect more than 1000 offshore and

concurrentonshoresiterecordsfromtheK-NETandSEMSprojects.Thesedataarecompared

statisticallyintermsofthepeakgroundacceleration(PGA),thenormalizedresponsespectra

ofthehorizontalandverticalcomponentsandthecorrespondingvertical-to-horizontal(V/H)

ratios.Theanalysisindicatesthatinthesameearthquakeeventandwithidenticalepicenter

distance,duetotheeffectsofseafloorsoftsedimentsandwaterlayer,theoffshorehorizontal

PGAissignificantlyamplified.Meanwhile,thePGA’sV/Hratiooftheoffshoregroundmotions

is much smaller than that of the onshore counterparts. For response spectra, the peak

platforms of offshore ground motions lag behind the onshore records. Also, the offshore

responsespectraatlongperiodsgaingreateramplifications,whichiscriticaltobottomfixed

offshore structures. The V/H ratios of response spectra, offshore versus onshore, exhibit

differenttrendsvaryingwithperiods.Finally,tofillupthegapofcurrentseismicdesignof

offshorestructures,astandardizedresponsespectrumissuggestedforthereferenceusein

designcodes.



132

A0355-Collapseperformanceassessmentofself-centeringprecastconcretewalls

withdifferentpost-tensioningandenergydissipationdesigns

HaoWua,YingZhoub

aAssistantresearcher,TongjiUniversity,[email protected]

dProfessor,TongjiUniversity,[email protected]

Previousresearchhaveprovedtheexcellentperformanceofself-centeringprecastconcrete

walls for use in seismic regions in terms of low damage and small residual deformation.

However, these studies have mainly focused on evaluating the hysteretic behavior of the

system through experimental testing and numerical simulation. This paper evaluates the

influences of different designs of post-tensioning (PT) and energy dissipation (ED)

components, which could be controlled by designers, on the collapse performance of self-

centeringprecastconcretewalls.Theeffectsofdifferentdesignselectionsfortheresponse

reductionfactor(R)andcollapsecriterionarealsoexamined.Tothisend,anexamplefour-

story self-centering precast wall building is designed and simulated using the numerical

modelthathasbeenverifiedbasedonexistedtestdata.Atotalofeightdifferentdesignsare

consideredfortheexamplebuildingusingvariousamountofPTandEDdesigns,anddifferent

Rvalues.Theestablishedparametricmodelsareanalyzedtoproducecollapsefragilitycurves

throughincrementaldynamicanalysisusing44groundmotions.Basedonresultsofcollapse

fragilitydata,collapseriskofalltheparametricmodelsareassessedaccordingtothestandard

procedureinFEMAP695.TheevaluationresultsshowthatEDdesignshavemoreinfluence

thanPTdesignstotheoverallcollapsefragilityforself-centeringprecastwalls.Nevertheless,

all the prototype walls in the current study are demonstrated to have acceptably low

probabilitiesofcollapse,whichmeettherequirementsinthedesigncode.



133

A0523-Dynamictestingofafull-scalefrp-retrofittedreinforcedconcretebuilding

frame

JiukShina,Jong-SuJeonb

aResearchSpecialist,KoreaInstituteofCivilandBuildingTechnology,[email protected]

bAssistantProfessor,AndongNationalUniversity,[email protected]

Manyexistingreinforcedconcretebuildingsdesignedinaccordancewithpre-1971codesare

generally dominated by weak column-strong beam behavior under seismic loading due to

inadequatereinforcementdetailing.Thisbehaviorcanleadtoprematurefailureunderseismic

loadsfromdamageconcentratedinthefirststoryofthestructure.Thispaperpresentsfull-

scale dynamic testing of a non-ductile reinforced concrete frame retrofitted using a fiber-

reinforced polymer jacketing system on the first story columns. This retrofit scheme was

determinedbasedonvisibledamagepatternsandlocations(e.g.flexural,shearandlap-splice

failureonthefirststorycolumns)ofanas-builttestframe.Thefull-scaledynamictestwas

performed to investigate the dynamic performance of the retrofitted building structure in

terms of the modal response, inter-story drift, and effectiveness of the fiber-reinforced

polymerjacketingsystem.Theresultsdemonstratethattheretrofitschemehelpeddevelopa

moreuniformstorydriftdistribution,workingtocounterthesoft-storymechanismcommonly

foundinreinforcedconcreteframesdesignedduringthisperiod.



134

A0530- Simplified model based on spectrum analysis for the optimal outrigger

locationofhigh-risebuildings

YingZhoua,LiliXingb,GuangxinZhouc

aStateKeyLaboratoryofDisasterReductioninCivilEngineering,TongjiUniversity,Shanghai


bStateKeyLaboratoryofDisasterReductioninCivilEngineering,TongjiUniversity,Shanghai


cStateKeyLaboratoryofDisasterReductioninCivilEngineering,TongjiUniversity,Shanghai


The outrigger system is a current alternative to reduce the dynamic response of high-rise

buildings.Theaimofthestudyistodevelopanalyticalmethodsforearthquakeresponseofa

conventionaloutriggersystemandtodeterminetheoptimaloutriggerlocation.Atheoretical

simplifiedmodelisdevelopedbasedonadynamictime-historyloadandisfurtherimproved

bymode-superpositionresponsespectrummethod.ThemodelisthencalibratedviaanANSYS

model, and the simplified model is applied to perform parametric analyses to acquire the

optimal outrigger location of each scheme. All data obtained from parametric analyses are

summarisedtosolvethefittingequationofoptimaloutriggerlocation.Finally,acomparison

of the results between time-history and spectra analysis suggest that the simplified model

basedonspectrumanalysiseffectivelysimulatestheseismicbehaviourofstructurewithan

outriggeranditscorrespondingfittingequationreasonablyexpressestheoptimaloutrigger

location of the aforementioned type of structure under seismic action. Additionally, the

optimal outrigger location is first proposed in the form of an explicit equation that is

convenientlyusedintheinitialdesignprocessofaconventionaloutrigger.



135

A0567-Modelingandperformanceassessmentofbase-isolatedbuildings

N.D.Olivetoa,A.Athanasioub,A.A.Markouc

aVisitingscholar,UniversityofCatania,[email protected]

bPostdoctoralresearcher,ConcordiaUniversity,[email protected]

cLecturer,AaltoUniversity,[email protected]

The behavior of high damping rubber bearings is highly complex. Existing models are

generally unidirectional and for the most part difficult to extend to general bidirectional

loading. One of the major limitations is their inability to characterize the behavior of the

bearingsatdifferentlevelsofsheardeformation.Inthepresentwork,asetofbidirectional

modelsareproposedandimplemented,obtainedbysimplecombinationsofwell-knownbi-

dimensionalformulations.Themodelsareshowntoaccuratelydescribetheresponseofthe

bearingsatlow,intermediateandhighstrainlevelsusingasinglesetofparameters.Numerical

simulations are carried out of a base-isolated building subjected bidirectional earthquake

excitation. An ensemble of earthquake records are selected based on site hazard

characteristicsandusedforaperformancebasedassessmentofthebuilding.



136

A0599-Verticalvibrationofend-bearingpilegroupsinviscoelasticsoillayer

LubaoLuana,XuanmingDingb,ChangjieZhengc

aPh.D,KeyLaboratoryofNewTechnologyforConstructionofCitiesinMountainArea,School

ofCivilEngineering,[email protected]

bProfessor,KeyLaboratoryofNewTechnologyforConstructionofCitiesinMountainArea,

SchoolofCivilEngineering,[email protected]

cLecturer,KeyLaboratoryofNewTechnologyforConstructionofCitiesinMountainArea,

SchoolofCivilEngineering,[email protected]

Ananalyticalsolutionisproposedforcalculatingthesteady-stateimpedancefactorsofpile

groupswitharbitrarypilememberssubjectedtoharmonicverticalloads.Anewinteraction

factorbetweentwopilesareintroducedbydefinitiononthebasisofsoilresistanceinsteadof

piledisplacements,toconsidertheeffectofpilegeometryonpile-soil-pileinteraction.Stress

distributionof thesoilaroundtheverticallyvibratingpile is firstdeterminedtodefinethe

interactionfactor.Accordingly,impedancefactorsofthepilegrouparederivedusingthenew

defined interaction factor and the popular principle of superposition. Finally, numerical

resultsareobtainedfortypicalparameterstoinvestigatethepilegeometryeffectsandoffer

insightintothemechanismofloadtransferbetweenpilesandtheirsurroundingsoils.



137

A0614-Balancedesignbasedonthehorizontalandverticalcollapsemarginratios

ofsteelframestructures

ZhengHea,JeriniainaSitrakaTantelyb

aPh.D.,Dept.ofCivilEngineering,DalianUniversityofTechnology,[email protected]

dPh.D.candidate,Dept.ofCivilEngineering,DalianUniversityofTechnology,

[email protected]

Thecollapsesofsteelframestructuresunderstrongearthquakeshaveraisedmanyquestions

regardingtheadequacyofthecurrentseismicprovisionstopreventapartialortotalcollapse.

Theyhavealsobroughtupquestionsastowhatarethetypicalcollapsemechanismsforthe

buildingstructures,what istheinherentsafetymarginincode-designedstructuresinboth

lateralandverticaldirections,howtostrengthenthestructurestoeffectivelyincreasesuch

margins,andhowtobalancethesemarginstooptimizetheoverallsafetyofthestructures.

Thispaperpresentsamethodologytoimprovetheglobalcollapseresistanceofthestructures

bybalancingthecollapsemarginratio(CMR)inbothlateralandverticaldirections.Basedon

theconceptofsafetybalancedesign,thecharacteristicsofunbalanceddesignareidentifiedto

develop a series of steel frame structures with typical failure mechanisms. The safety

assessmentofeachexamplestructure,intermofhorizontalandverticalCMR,isperformed.

TheoutcomespermittodeveloptheenvelopeofCMR,whichreflectstherelationshipbetween

thetwoCMRs.Thesuperpositionoftheparametersofthestructuralcollapsesensitivitytothe

envelope of CMR allows identifying the critical CMR values in both lateral and vertical

directions.



138

A0673-Seismicvulnerabilityofrailwaynetworkbasedontherunning-trainssafety

evaluation

ChengYANGa

aAssociateProfessor,[email protected]

The medium-small earthquakes could induce the high-speed train derailment on bridges

withoutanybridgestructuraldamage,leadingtotherailwaylinesblockage.Fordepictingthe

seismic hazard scenario of high-speed railway network, a framework is proposed to

investigate the connectivity vulnerability of China high speed-railway network under the

effect of regional earthquake. Based on a dense bridges network covering an earthquake-

proneareaofsouthwestChina,thePSHAisperformedtogettheseismichazardparameters

ofeverybridgesite.Asaresult,theaccelerationresponsespectrumcorrespondingtodifferent

earthquake recurrence interval is obtained. After vehicle-bridge-earthquake dynamic

analyzing, the seismic induced derailment probability of vehicles moving on the bridge is

obtainedandtakenastheclosingprobabilityofthenodesinthenetwork.Basedonthenode

closing probability corresponding to different levels of earthquake, the Order-X network

connectivityalgorithmispresentedtocalculatethenetworkconnectivity.Theresultsshow

thatthedifferencebetweenthemicro-zoningintensityandmacro-levelintensity,whichleads

to the difference in hazard assessment results for bridges, is the key factor that cause the

difficultiesofconnectivityvulnerabilityanalysis,hence,thesafetyevaluationofrunning-trains

onbridgesisindispensablefortheseismicvulnerabilityanalysisofthebridgesnetwork.



139

A0754-Seismicresponseanalysisofliquidpipesinbuilding

HaoRunxiaa,YuanPengchengb

aAssociateprofessor,CivilEngineeningSchool,InnerMongoliaUniversityofScience&


dPostgraduatestudent,CivilEngineeningSchool,InnerMongoliaUniversityofScience&


Theliquidpipesinthebuildingareusedasnon-structuralmembersattachedtoeachfloor,

which is of great significance for ensuring the normal use of the building. Based on the

influenceofeachfloorofthemainstructureonthepipeline,establishesthemainstructure-

pipe integral coupling model and the pipeline multi-point excitation model to analyze the

seismicresponseofthepipeline,andcomparestheresultsofthetwotoproposeamulti-point

excitationpipelineseismicresponseanalysismethod.Throughthetime-historyanalysisofthe

7-story frame structure, the influence law of ground motion intensity variation on the

accelerationamplificationcoefficientofeachfloorisobtained.,andtheseismicresponseof

thefloorresponsespectrumanalysispipelineisestablished.



140

A0851-Multiscalerandomfields-baseddamagemodelingandanalysisofconcrete

structures

HaoZhoua,JieLib,BillieF.SpencerJr.c

aPhD,DepartmentofCivilEngineering,SouthChinaUniversityofTechnology,381Wushan

Road,Guangzhou,China,[email protected]

bProfessor,DepartmentofStructuralEngineering,TongjiUniversity,1239SipingRoad,

Shanghai,China,[email protected]

cProfessor,DepartmentofCivilandEnvironmentalEngineering,UniversityofIllinoisat

Urbana-Champaign,IL61801,[email protected]

Anewapproachtowardsincorporatingthestochasticnatureofdamageconstitutiverelations

ispresentedforthefiniteelementanalysisofconcretestructures.Withintheframeworkof

stochastic damage mechanics, the spatial variability of concrete is modeled as a two-scale

stationaryrandomfields.Atthemicro-level,thedamageevolutionlawofconcreteismapped

to a random field corresponding to the microscopic fracture strain. At the macro-level, the

strengthdistributionofconcretecomponentsformsalognormallydistributedrandomfield.

Thecovarianceconstraintisdevelopedtobridgethegapbetweenthetwo-scalerandomfields

suchthatthescale-of-fluctuationoftherandommaterialpropertyissatisfiedinbothscales.

Taking advantage of the stochastic finite element method, both the microscopic random

damageevolutionofconcreteandthefluctuationofmacroscopicstructuralresponsescanbe

numerically represented. Stochastic structural modeling and damage analysis regarding a

high-risereinforcedconcretestructureiscarriedouttoillustratetheproposedmethod.Itis

shownthatthenonlinearbehaviorofthestructuresubjectedtostrongdynamicactionsmay

exhibitsignificantvariabilityandevenitsintendedcollapsemodesmaybealteredmerelydue

torandomnessinmicroscaleofconcrete.



141

A0883-Dynamictestingofafull-scalefrp-retrofittedreinforcedconcretebuilding

frame

JiukShina,Jong-SuJeonb

aResearchSpecialist,KoreaInstituteofCivilandBuildingTechnology,[email protected]

dAssistantProfessor,AndongNationalUniversity,[email protected]

Manyexistingreinforcedconcretebuildingsdesignedinaccordancewithpre-1971codesare

generally dominated by weak column-strong beam behavior under seismic loading due to

inadequatereinforcementdetailing.Thisbehaviorcanleadtoprematurefailureunderseismic

loadsfromdamageconcentratedinthefirststoryofthestructure.Thispaperpresentsfull-

scale dynamic testing of a non-ductile reinforced concrete frame retrofitted using a fiber-

reinforced polymer jacketing system on the first story columns. This retrofit scheme was

determinedbasedonvisibledamagepatternsandlocations(e.g.flexural,shearandlap-splice

failureonthefirststorycolumns)ofanas-builttestframe.Thefull-scaledynamictestwas

performed to investigate the dynamic performance of the retrofitted building structure in

terms of the modal response, inter-story drift, and effectiveness of the fiber-reinforced

polymerjacketingsystem.Theresultsdemonstratethattheretrofitschemehelpeddevelopa

moreuniformstorydriftdistribution,workingtocounterthesoft-storymechanismcommonly

foundinreinforcedconcreteframesdesignedduringthisperiod.



142

A0899- Multi-scale comprehensive simulation of concrete shear wall models:

numericalsimulation

JingranHea,JianbingChenb,XiaodanRenc,JieLid

aPh.D.candidate,TongjiUniversity,Shanghai,China,[email protected]

bProfessor,TongjiUniversity,Shanghai,China,[email protected]

cAssociateProfessor,TongjiUniversity,Shanghai,China,[email protected]

dDistinguishedProfessor,TongjiUniversity,Shanghai,China,[email protected]

Concretestructuresarewidelyusedintheworld,particularlyinChina,wheremostareasare

earthquake prone zone, therefore their safety is of great importance. The prediction and

simulation of such structures under strong earthquakes are essential to the performance

evaluationandreliabilityassessment.However,duetotheuncertaintiesinmaterialproperties

and numerical modelling, the accurate simulation of complex concrete structures is still a

greatchallenge.Thelackofknowledgeintheconstitutivelawofconcrete,forinstance,isone

of the uncertainties that is most essential to the simulation. In recent years, a stochastic

damagemodelforconcretematerialhasbeendeveloped.Thismesoscopicphysicalmodelcan

capturethemechanicalbehaviorofconcrete.Inthepresentpaper,thepredictionofresponse

ofastructuralmodelinshaketabletestsisconductedbydifferentconstitutivelaws,including

theconcretedamageplasticmodel(CDP)which isembeddedintheABAQUSsoftware, the

stochastic damage model (SDM) and the stochastic damage model with softening effect

(SDMs).Thesimulationresultsoftheseconstitutivelawsarecomparedwiththetestresults,

showingthattheSDMandSDMsperformancebetterthantheCDP.Theresultdemonstrates

thattoadoptappropriateconstitutivelawofconcrete,includingtheinvolvementofcompound

effects of concrete and reinforcement, is essential to the simulation of strong nonlinear

behaviorsofconcretestructures.



143

MS13: Damage and Failure Modeling and Analysis of

Concrete and Structures

A0119-AfractureproblemwithasurfaceenergyintheSteigmann-Ogdenform

AnnaZemlyanovaa

aAssociateProfessor,DepartmentofMathematics,KansasStateUniversity,Manhattan,KS,

USA,e-mail:[email protected]

A problem of a straight mixed mode non-interface fracture in an infinite plane is treated

analytically with the help of complex analysis techniques. The surfaces of the fracture are

subjectedtosurfaceelasticityintheformproposedbySteigmannandOgden.Theboundary

conditions on the banks of the fracture connect the stresses and the derivatives of the

displacements.Themechanicalproblemisreducedtoasystemofsingularintegro-differential

equationswhichisfurtherreducedtothesystemsofequationswithlogarithmicsingularities.

ItisshownthatmodelingofthefracturewiththeSteigmann-Ogdenelasticityproducesthe

stressandstrainfieldswhichareboundedatthecracktips.Theexistenceanduniquenessof

thesolutionforalmostallthevaluesoftheparametersisprovedbyreducingthesystemof

singularintegro-differentialequationstothesystemofweakly-singularintegralequations.It

isshownthatintroductionofthesurfacemechanicsintothemodelingoffractureleadstothe

size-dependent equations. A numerical scheme of the solution of the systems of singular

integro-differential equations is suggested, and the numerical results are presented for

differentvaluesofthemechanicalandthegeometricparameters.



144

A0124- MULTILEVEL MODELING OF FIBER-REINFORCED CONCRETE AND

SIMULATIONOFCRACKINGINTUNNELLININGSEGMENTS

Y.ZhanaandG.Meschkeb

aSeniorR&DEngineer,ShanghaiConstructionGroupCo.,Ltd.,Shanghai200080,China,

email:[email protected]

bProfessor,InstituteforStructuralMechanics,RuhrUniversityBochum,Bochum44801,

Germany,email:[email protected]

Aimingatthemodel-basedanalysis,designandoptimizationofengineeringstructuressuch

assegmentaltunnel liningsmadeof fiber-reinforcedconcrete(FRC),amultilevelmodeling

framework consisting of a series of model components is developed, which facilitates the

investigationoftheeffectofvariousdesignparameters(concreteclass,fiberproperty,fiber

distribution,etc.)atdifferentlengthscales.Thefundamentalingredientatthelevelofsingle

fibersisananalyticalmodelallowingthepredictionofthepulloutresponseofasteelfiber,

eitherstraightorwithhookedend,withorwithout inclinationwithrespect to the loading

direction.ForanopeningcrackinaspecificFRCcomposite,employingthesinglefiberpullout

model,thefiberbridgingeffectiscomputedviatheintegrationofthepulloutresponsesofall

the fibers intercepting the crack, taking particularly the anisotropic fiber orientation into

consideration. Based on the numerically integrated results of crack bridging effect, the

corresponding analytical surrogate function form of the traction–separation relation is

derived. For the numerical analysis of fracture processes and failure mechanisms at the

structurallevel,thefiniteelementmethodusinginterfacesolidelementsequippedwiththe

traction–separation law obtained from the crack bridging model is used to capture the

cracking phenomena and the postcracking ductile behavior of FRC. An implicit/explicit

integrationschemeandanadaptivemesh-processingtechniqueareimplementedtoenhance

therobustnessandtoreducetheexpenseofcomputation.Havingthesemodelcomponents

validated,thecompletemultilevelmodelingframeworkisappliedtothesimulationoffailure

behavior of tunnel lining segments made of FRC, demonstrating good performance in

followingtheinfluenceofdifferentdesignparametersfromthesinglefiberleveltothescale

ofengineeringstructures.Therefore,thepresentworkconstitutestheessentialingredientsof

a“virtuallaboratory”forthedesignandoptimizationofFRCmaterialsandstructures.



145

A0274-NUMERICALINVESTIGATIONOFCONCRETEAGEEFFECTONSHEARLOAD

CAPACITYOFPOST-INSTALLEDANCHORS

KrešimirNinčevića*,IoannisBoumakisaandRomanWan-Wendnera

aChristianDopplerLaboratoryforLife-CycleRobustnessinFasteningTechnologyUniversity

ofNaturalResourcesandLifeSciencesVienna,Austria.*CorrespondingAuthore-mail:

[email protected]

Fasteningsystemsarewidelyusedengineeringsolutionssupportinginnovativedemandsin

design. Fasteners are used to connect structural members or attach secondary elements.

Additionally, they see many others applications such as strengthening existing structures/

structuralmembers.Thepresentinvestigationfocusesontheshearloadcapacityofanchors

installedinconcreteclosetoanexistingedge.Thedominantfailuremechanisminthiscaseis

concreteconebreakout.Thisfailuremechanismhasbeeninvestigatedformanyyears,andas

aresult,differentanalyticalmodelshavebeenderivedasafunctionofembedmentdepthand

edgedistance,inthelattercasewithvaryingsuccess.Thesemodelsseemtobevalidsolutions

fordesigningsafeandreliablefasteningsystems.Nevertheless,noneofthemconsidersthe

complexagingnatureoftheheterogeneousmaterialconcrete.Indesignconcreteisconsidered

ahomogenousmaterialwithspatiallyconstantmaterialproperties.However, inreality the

mechanicalpropertiesarefunctionsofthelocalcementhydrationdegree,ratherthantime,

which not only depend on the mix design but also on the history of the environmental

boundary conditions (i.e. temperature and relative humidity). Consequently, the concrete

volume involved in the forming concrete breakout body is characterized by gradients of

materialproperties(andpotentiallyalsoshrinkagestrains)thatdonotscalewiththeedge

distance.Furthermore,aso-calledwall-effectisknowntoexist,i.e.theconcreteclosetothe

surface differs in composition and material properties from the bulk. This contribution

presents a large experimental campaign comprising shear tests on post-installed bonded

anchors for three concretes, two ages and three edge distances each. Tests include a full

fracturemechanicalcharacterizationatbothages,calorimetry,creep,andshrinkagetests.A

discretemulti-physicsframeworkisappliedinordertoinvestigatetheinfluenceoftheedge

distanceontheconcreteshearcapacityexplicitlyaccountingfor(i)thewall-effect,(ii)curing

relatedgradientsinmaterialpropertiesand,thus,aging,and(iii)thedistributionofshrinkage

strainsandearlyagedamage.TheLatticeDiscreteParticleModel(LDPM)isusedtosimulate

concrete at the meso-scale and to mimic its heterogeneity while the degree of curing is

determinedbythehygro-thermalchemical(HTC)model.



146

A0378-Analyticalmodelofrockingelementswithdamagedcorners

HaoranCuia,DechengFengb,GangWuc,*

aPh.D.candidate,SchoolofCivilEngineering,SoutheastUniversity,e-mail:

[email protected]

bLecturer,SchoolofCivilEngineering,SoutheastUniversity,e-mail:[email protected]

cProfessor,KeyLaboratoryofConcreteandPrestressedConcreteStructuresoftheMinistry

ofEducation,SoutheastUniversity,e-mail:[email protected]

Therestraintsatthejointsofrockingstructuresarereleasedsothatrockingmotionscanoccur

during earthquakes. Damage to the main structure is limited by the concentrated

displacement at rocking interfaces, while corners of reinforced concrete rocking elements

crushduringtherockingmotion.Therockingelementexhibitsanonlinearbehaviordueto

the absence of tensile resistance in the end section in prerocking phase. A new analytical

modelwhichreferstoanexistinganalogousspreadplasticitymodelofrockingelementsis

developedtocalculatethedeformationofdamagedrockingelementsbeforerockingbasedon

virtueworkprinciple.Adamageinfluencecoefficient isproposedtoconsidertheeffectsof

damaged corners on the entire rocking elements, with a new effective stiffness ratio

accountingfortheplasticdeformationincalculation.Theanalyticalmodelisverifiedbythe

finiteelementmodelsimulationandtheresultsofexistingexperiments.Theresultsindicate

thattheanalyticalmodelproposedinthispapercouldaccuratelypredictthedeformationof

rockingelementsbeforeandafterdamage.Theeffectivestiffnessratiorelatedtothenormal

stressdistributionatthecontactsurfaceisprovedtobeapplicableintheanalysisofrocking

elementsbeforerocking.Byadjustingthedamageinfluencecoefficient,theeffectsofdifferent

damagedegreesofcornersonthestiffnessofrockingelementscanbeexplicated.Thedamage

influence coefficient increases as the range of damaged corners increase, which finally

decreasesthelateralstiffnessoftheentirerockingelement.



147

A0463- Simplified modal properties analysis of soil-base-isolated-structure

systemswithlargeaspectratio

D.S.Du,S.G.Wanga

aCollegeofCivilEngineering,NanjingUniversityofTechnology,Nanjing210009,China

Asimplifiedmethodologyisrigorouslystudiedinthispapertoanalyzeseismicresponseof

base-isolatedstructureswithdynamicsoil-structureinteraction(SSI)beingconsidered.The

proposedmethodologyisdevelopedbasedontheexistingsimplifiedmethodologywhichis

only applicable for non-isolated structures. The base-isolated structure model with two

degreesoffreedomissupportedbyswayingandrockingspringsandbythecorresponding

dashpots. Rigorous mathematical derivation is performed, and closed-form formulas of

natural periods, modes and modal damping ratios are derived. Furthermore, the overall

accuracy of the proposed methodology was checked against the results of the rigorously

derivedcomplexeigenvalueapproachproposedbyConstantinouandKneifati.Aparametric

studyisalsoconductedontheSSIeffectsofbase-isolatedstructures,whichturnsoutthattall

and slender structures with stiff isolation systems are more affected by SSI effects in

comparison to flexible superstructures. The proposed method provides a feasible way to

evaluateSSIeffectsofbase-isolatedstructuresefficientlyduringtheschematicdesignphase.



148

A0466- A NEW MODEL FOR DUCTILE FRACTURE PREDCTION WITH STRESS

TRIAXIALITYANDLODEDEPENDENCE:MODELLINGANDCALIBRATING

BoYanga,DeyangKongb

a,Professor,ChongqingUniversity,e-mail:[email protected]

b,Ph.D,ChongqingUniversity,e-mail:[email protected]

Fracture prediction is of great importance in structural steel in order to simulate the

progressivedamageandcollapseofsteelstructurebuildings.Whenfractureoccursincritical

components,suchasbeam-columnconnections,thestructuralperformanceincludingtheload

transfer paths and load-resistance mechanisms may be different, which may lead to an

overestimation of structural performances against progressive collapse, leaving a potential

threattohumanlives.However,previousstudiesonductilefractureofstructuralsteelsare

relatively limited. In this paper, a new ductile fracture model was developed based on

microstructural analysis of fracture process including void nucleation, growth and

coalescence.AseriesoffracturetestswerecarriedoutbyusingQ690Dsteeltocalibrateand

verifythenewlyproposedmodel.Thesetestsincludingtensiletestsofsmoothandnotched

roundbarspecimensandshearspecimenswereexpectedtofailatdifferentstresstriaxiality

regimes.Itisfoundthatthenumericalpredictionsagreewellwiththeexperimentalresults,

which demonstrates the new model can describe the ductile fracture behavior with high

accuracy.



149

A0504- Development and Identification of Hysteresis Model for Reinforced

ConcreteColumnsFailinginDifferentModes

XinliangLyua,XiaodanRenb,ChaolieNingc*

aMasterstudent,CollegeofCivilEngineering,TongjiUniversity,Shanghai200092,China,e-

mail:[email protected]

bAssociateProfessor,CollegeofCivilEngineering,TongjiUniversity,Shanghai200092,China,

e-mail:[email protected]

cAssistantProfessor,ShanghaiInstituteofDisasterPreventionandRelief,TongjiUniversity,

Shanghai200092,China,*CorrespondingAuthore-mail:[email protected]

Reinforced concrete (RC) columns have three different failure modes during earthquake

excitations,respectivelyflexural failuremode, flexural-shearfailuremodeandshear failure

mode, then exhibiting different hysteresis characteristics such as strength deterioration,

stiffnessdegradationandpinchingphenomenainapplications.Thus,thedevelopmentofan

effectiveandcomputationallyefficienthysteresismodeliscrucialfortheevaluationofseismic

performance of existing RC columns. However, the available hysteresis models are rather

complicated and the parameters involved in the hysteresis models often lack physical

interpretation, which largely prevents its flexible applications in practice. Therefore, a

simplifiedhysteresismodel is firstproposed in thisstudywithsevenmodelparametersto

describethedifferenthysteresisloopofRCcolumnsunderdifferentfailuremode.Then,the

differential evolution (DE) algorithm is employed to identify the value of hysteresis model

parametersbycomparingwiththeexperimentaldataof251RCcolumnsunderquasi-static

testing. Based on the identified value of hysteresis model parameters, a comprehensive

comparison of critical model parameters is finally made to provide a quantitative

understanding on the difference of the three different failure modes. According to the

investigation,itisfoundthatthehysteresismodeldevelopedwiththesevenmodelparameters

is adequate to capture the typical hysteresis characteristics of RC columns under different

failure mode. The DE algorithm is also effective to identify the value of hysteresis model

parameters.ForRCcolumnsfailinginflexural-shearmodeandshearmode,severerstrength

deterioration,stiffnessdegradationandpinchingphenomenacanbeobserved.Therefore,a

practical way should be further established to estimate the value of hysteresis mode

parameters based on the critical physical parameters of RC columns for facilitating its

applications.



150

A0604-Three-DimensionalFiniteElementModellingofUHPFRCJacket-Retrofitted

PiersUnderCyclicLoading

HaipengLeia,TengTongb,WeidingZhuoc,ZhaoLiud

aPhDcandidate,SoutheastUniversity,e-mail:[email protected]

bLecturer,SoutheastUniversity,e-mail:[email protected]

cPhDstudent,SoutheastUniversity,e-mail:[email protected]

dProfessor,SoutheastUniversity,e-mail:[email protected]

Inseismicevaluationofhighwaybridges,reinforcementconcrete(RC)piersarecriticaland

vulnerable components. There exists numerous old bridge piers with lower longitudinal

reinforcement ratio in China. Recently, the authors proposed a new retrofitted method by

usingultra-highperformancefiberreinforcedconcrete(UHPFRC)jacket.Cyclicloadingtest

showed that UHPFRC was a promising material significantly enhanced RC piers’ seismic-

resistantcapacity.Inthisstudy,the3Dsolidfiniteelementmodelisproposed,relyingonthe

implicitmethod,tonumericallyinvestigatetheeffectivenessofUHPFRCjacket.The3Dmodel

integratestheconcretedamageplasticity(CDP)modelfornormalconcreteandUHPFRC,the

constitutivemodelforreinforcementsincludinglocalbucklingandlow-cyclefatigue,andthe

strainpenetrationeffectbetweenconcreteandreinforcement.The3Dmodellingschemeis

implementedinthecommercialfiniteelementprogramABAQUS.Theconstitutivemodelfor

reinforcements is realized in UMAT routine, and the bond between concrete and

reinforcementismodelledthroughUELroutine.Thecomparisonwiththetestvalidatesthe

proposed3Dmodel.TheconfinementeffectfromUHPFRCjacket,isanalyzedindetailwiththe

numerical tool. The influencing factors of UHPFRC jacket on the effectiveness of seismic

retrofit,includingtheheightandthickness,areinvestigatedindetail.



151

A0635-Spatialcorrelationindisorderedheterogeneousmaterials

DingZhaodonga

aSchoolofCivilEngineering,HefeiUniversityofTechnology,Hefei,China

The fracture patterns and damage localization of heterogeneous materials are strongly

influenced by the disorder at microscale. This paper investigates the spatial correlation of

strengthdistributionofbasicelementssystematicallywithrandomfusemodel(RFM).With

the same level of disorder, the spatial correlation determines different failure modes

characterized by transition from ductile failure to brittle failure. The statistical avalanches

scaling results also show not only the disorder but also the spatial correlation have great

influenceonmaterial failurecharacteristicswhich linkwith the firstorderandcontinuous

phasetransition.



152

A0970-Anequivalentstrainbasedmulti-scaledamagemodelofconcrete

ShixueLianga,JinZhangb

aLecturer,SchoolofCivilEngineeringandArchitecture,ZhejiangSci-TechUniversity,e-mail:

[email protected]

bGraduateStudent,SchoolofCivilEngineeringandArchitecture,ZhejiangSci-Tech

University,e-mail:[email protected]

Amulti-scaledamagemodelofconcreteisproposedbasedontheconceptofenergyequivalent

strain for generic two- or three-dimensional applications. Continuum damage mechanics

servesastheframeworktodescribethebasicdamagevariables,namelythetensileandshear

damage.ThehomogenizedHelmholtzfreeenergyisintroducedasthebridgetolinkthemicro-

cell and macroscopic material. The crack propagations in micro-structures subjected to

tensionandsheararemodeled,andtheHelmholtzfreeenergyinthecrackedmicro-structure

is calculated and employed to extract the damage evolution functions in the homogenized

continuum. Based on the damage energy release rates (DERRs) and damage consistent

condition,theenergyequivalentstrainisusedtoexpandtheuniaxialdamageevolutiontothe

multi-axialdamageevolution.Agreementswithexistingexperimentaldatathat includethe

uniaxialtensileandcompressivetests,thebiaxialcompressionprovethecapacityofthemulti-

scaledamagemodelinreproducingthetypicalnonlinearperformancesofconcretespecimens.

Thesimulationofreinforcedconcreteundergrounddiaphragmwallfurtherdemonstratesits

applicationtoconcretestructures.



153

MS14: Uncertainty Quantification and Reliability-based

Performance Evaluation

A0020- ROBUST STATISTICAL METHODS FOR POWER SPECTRUM ESTIMATION

FROMMULTIPLESOURCERECORDS

MarcoBehrendta,LiamComerfordb,MichaelBeerc

aM.Sc.,InstituteforRiskandReliability,LeibnizUniversityHanover,e-mail:

[email protected]

bDr.,InstituteforRiskandReliability,LeibnizUniversityHanover,e-mail:

[email protected]

cProf.Dr.-Ing.,InstituteforRiskandReliability,LeibnizUniversityHanover,e-mail:

[email protected]

Modernapproachestosolvedynamicproblemswhererandomvibrationisofsignificancewill

inmostofcasesrelyuponthefundamentalconceptofthepowerspectrumasacoremodelfor

excitation&responseprocessrepresentation.Thisispartlyduetothepracticalityofspectral

modelsforfrequencydomainanalysis,aswellastheireaseofuseforgeneratingcompatible

timedomainsamples.Suchsamplesmaybeutilizedfornumericalperformanceevaluationof

structures,thoserepresentedbycomplexnon-linearmodels.Utilizationofensemblestatistics

willbeconsideredfirstforstationaryprocessesonly.Forastationarystochasticprocess,its

powerspectrumcanbeestimatedstatisticallyacrossalltimeorforasinglewindowintime

acrossanensembleofrecords.Inthiswork,itisshownfirstthatensemblecharacteristicscan

beutilizedtoimprovetheresultingpowerspectrabyusingestimationsofthemedianinstead

ofthemeanofmultipledatarecords.Theimprovedpowerspectrumwillbemorerobustin

thepresenceofspectraloutliers.Themedianspectrumwillresultinmorereliableresponse

statistics, particularly when source ensemble records contain low power spectra that are

significantly below the mean. As an extension, a weighted median spectrum will also be

utilized,baseduponthespectraldistanceofeachrecordfromthemedian,whichwillshiftthe

estimatedspectruminthedirectionoftheclosestsamples.Tovalidatetheimprovedmethod

ofestimatingpowerspectrawindandearthquakeloadsareappliedtohigh-risebuildings.



154

A0131-ANALYZINGCOMPLEXSYSTEMSUNDEREPISTEMICUNCERTAINTIES

MichaelBeer

InstituteforRiskandReliability,LeibnizUniversitätHannover,Germany,e-mail:

[email protected]

InstituteforRiskandUncertainty,UniversityofLiverpool,UK

InternationalJointResearchCenterforEngineeringReliabilityandStochasticMechanics

(ERSM),TongjiUniversity,China

Our structures, systems and infrastructure are characterized by a rapid growth in scale,

complexityandinterconnectionwithasignificantinvolvementofdiversehumanbehaviour

withcriticalinfluence,sothatuncertaintiesandrisksareinvolvedtoagreaterextentthanever

before.Thesestructures,systemsandinfrastructureare,toasignificantextent,criticalforthe

functionality of our economic and societal life, and thus, require proper approaches and

measures to verify and ensure their reliable performance. Reliability and performance

analysis,however,becomeincreasinglycomplicatedduetouncertaintiesandcomplexity.The

realisticquantificationofuncertaintiesandtheirnumericallyefficientprocessingincomplex

analysesarethetwokeychallengesinthiscontext.Thiskeynotelectureaddressesthesetwo

challenges. Approaches to deal with epistemic uncertainties are discussed, with focus on

impreciseprobabilitiesandinthecontextofstructuralandsystemreliabilityassessment.The

concept of survival signature is presented to analyse complex systems efficiently. Novel

pathways to capture interdependencies between systems while estimating their reliability

efficientlyinatimedependentmannerarediscussed.Engineeringexamplesarepresentedto

demonstratethecapabilitiesoftheapproachesandconcepts.



155

A0179- EFFICIENT BRIDGE LIFETIME ASSESSMENT BY TRAFFIC LOAD MODEL

UPDATINGANDSUBSETSIMULATION

StephenWua,He-QingMub*,Hou-ZuoGuoc

aAssistantProfessor,TheInstituteofStatisticalMathematics,Tokyo190-8562,Japan.E-mail:

[email protected]

b*AssociateProfessor,SchoolofCivilEngineeringandTransportation,StateKeyLaboratory

ofSubtropicalBuildingScience,SouthChinaUniversityofTechnology,Guangzhou510640,

P.R.China.CorrespondingAuthorE-mail:[email protected]

cStudent,SchoolofCivilEngineeringandTransportation,SouthChinaUniversityof

Technology,Guangzhou510640,P.R.China.

Wedemonstrateaproof-of-conceptstudyonefficientbridgelifetimeassessmentusinglimited

amount of traffic load data. Conventional approach fits a standard distribution, such as a

normaldistribution,withobservedtrafficloadinagivenperiod.Then,thedistributionisused

to predict future traffic load, leading to the final lifetime assessment of a bridge. As the

reliability estimation of a bridge depends heavily on the rare traffic load effect events, the

conventionalapproachisinefficientandinaccurateforpracticalpurposes.Weproposeamore

effectiveuseofthetrafficloaddatausingabetterbridgereliabilityassessmentframework.

Ourframeworkinvolvesareal-timeupdatingloopcomposedoftwocomputationalmodules:

(1) a traffic load simulation model continuously trained by real data, and (2) a machine

learningmodel forbridgeresponsepredictiontrainedbytheupdatedtraffic loadmodel.A

reliablesimulationmodelcanguaranteethesupplyofsufficientdataforaccuratereliability

assessment,andamachinelearningmodelcanspeedupthereliabilityestimationprocess.To

further improve the efficiency of our algorithm, we employ the popular subset simulation

method toestimateextremely small failureprobability values.Theproposed framework is

validatedbysimulatedexamples.



156

A0203-StochasticStayCableForceModelingUsingMonitoringDatafromaCable-

stayedBridge

HaijunZhoua,JunhuiLiub,QiWenc,LiminSund

aPhD,Professor,GuangdongProvincialKeyLaboratoryofDurabilityforMarineCivil

Engineering,ShenzhenUniversity,e-mail:[email protected]

bResearchAssistant,GuangdongProvincialKeyLaboratoryofDurabilityforMarineCivil


cResearchAssistant,GuangdongProvincialKeyLaboratoryofDurabilityforMarineCivil


dPhD,Professor,StateKeyLaboratoryforDisasterReductioninCivilEngineering,Tongji

University,Shanghai200092,CHINA,e-mail:[email protected]

The monitoring data of cable force, cable temperature from a cable-stayed bridge were

analyzed.Thedailyaveragevaluesofcableforceandcabletemperatureareusedtoeliminate

the variation effects of one day’s temperature. Then the data of cable force and cable

temperature were linear regression analyzed. The results showed that the coefficient of

determinationwasabout0.3andtheresiduewassymmetricallyaroundtheregressionline.

TheresiduecableforcevariationalonetimewasthenmodeledaspotentiallyGaussianand

homogeneous stochastic fields. Autocorrelation functions and marginal probability

distributionfunctionsweredeterminedfortheresidualradiusstochasticfield.Itwasfound

that the residual value of cable force was stationary and the marginal distribution did not

rejectnormaldistribution.Thestochasticmodelofcableforcethateliminatingtheeffectsof

cabletemperaturewasestablishedbasedonabovestudies.



157

A0222- Multi Level Moving Particles Simulation for Reliability Assessment with

ApproximateLimiteStateFunctions

C.Proppea

aChairofEngineeringMechanics,KarlsruheInstituteofTechnology,Kaiserstr.10,Bdg.10.23,

76131Germany,e-mail:[email protected]

MarkovChainMonteCarlosimulationmethodsallowestimatingsmall failureprobabilities

efficiently,evenforproblemsthatinvolveahigh-dimensionalvectorofinputrandomvariables.

Subsetsimulationcanbeconsideredasthemostprominentmethodinthisclass.Insubset

simulation, the failure probability is computed as the telescoping product of larger

probabilitiesthatrequiresamplingfromconditionaldistributions.Recently,analternativeto

subsetsimulationinthesenseofparticlemethodshasbeenproposed,whereathresholdis

associatedtoeachsample,samplesaremovedtonewpositionsinthedesignspaceandthe

numberofmovesfortheinitialsamplestoreachthefailureregionarecountedandyieldan

estimator for the failureprobability,which isofcomparableaccuracyandefficiencyas the

subsetsimulationestimator.Thealgorithmallowsforaneasyparallelimplementation.Justas

for subset simulation, sampling from conditional distributions is required when moving a

particle.Inmostpracticalapplications,thelimitstatefunctionisapproximatednumerically

with a certain numerical error h. In order to obtain an efficient simulation algorithm, it is

necessarytobalancethestatisticalerrorandthenumericalerror.Inthispresentation,amulti

levelmovingparticlessimulationmethodisproposedthatbalancesbotherrorsbycomputing

atelescopingsumofestimatesforthenumberofmoves.Foreachterminthetelescopingsum,

itisnecessarytocomputeascorrectorthedifferenceofthenumberofmovesforeachinitial

samplewithtwoconsecutiveaccuracylevelsusingthesamerandomnumbersintheMarkov

Chain Monte Carlo simulation. For the multi level moving particles method, the sample

variancedecreaseswithdecreasingnumericalerror.Thus,thenumberofsamplesthathasto

beevaluatedwithhighaccuracyisreducedcomparedtoasinglelevelcomputation.Therefore,

theproposedalgorithmisveryefficientforproblemswherehighlyaccurateevaluationsofthe

limitstatefunctionarenecessaryandrequireahugecomputationaleffort.



158

A0389-PrestressedConcreteBeamsFailingduetoWeb-crushing:Uncertaintyand

Reliabilityanalysis

OladimejiBenedictOlalusia

aStellenboschUniversity,SouthAfrica,e-mail:[email protected]

Shearfailureinprestressedconcretebeamswithstirrupreinforcementsandrelativelythin

websmaybegovernedbyweb-crushingfailure.Inthisscenario,theconcretediagonalswould

crushbeforetheyieldingoftheshearreinforcement,resulting inabrittlefailuremode.An

accurate method for predicting web-crushing failure is paramount since web-crushing is

catastrophicandcouldoccurwithoutwarning(brittlefailure).Theaccuratepredictionofthe

web-crushingstrengthofbeamsisaninvolvedprocess.Consequently,manycodesofpractices

have resorted to implementing simplified methods for predicting web-crushing failure in

beams.Therefore,itseemedreasonabletoassesshowwellthedesignprocedurescanpredict

theweb-crushingstrengthinprestressedconcretebeams.Thepaperaimstoinvestigatethe

modeluncertaintyandbiasrelatedtoEC2web-crushingfunctionusingthecomprehensive

databasethatisexclusivelyfocusedonprestressedconcretebeamswithweb-crushingfailure.

The measured web-crushing strengths from the experimental tests are compared with the

unbiased predicted web-crushing strengths obtained from Eurocode 2. Correlation and

regression analysis was also conducted to expose its dependency on some of the essential

variables affecting web-crushing strength. The model uncertainty and bias related to the

unbiasedEC2designfunctionforpredictingweb-crushingfailurewasfoundtohaveamean

value�� = 1.05and standard deviation�� = 0.15. The derived model factor observations

wereshowntobesensitivetotheamountofshearreinforcement��andbeamwidth��.

Subsequently, the derived model error statistics were used as input to assess the implicit

safetylevelofEC2designfunctionforweb-crushingfailure.Reliabilityassessmentusingthe

FORMprocedurewasconductedtohighlightthesafetyperformanceregimesobtainedfora

limited parametric range of ��where web-crushing failure governs. The concrete

strength,stirrupspacing,yieldstrengthofstirrups,geometricalpropertiesandmodelerror

werealltreatedasrandomvariables.Theresultsindicatedanincreaseinestimatedreliability

index(β)values as shear reinforcement��increases and a decrease in reliability as

concretestrength��increases.



159

A0421-Bearingcapacityfittingandunfavorablegeometricdefectsanalysisofsteel

archbasedonmultipleresponsesurfaces

JunlinZhenga,JunLuob,QianqianYina

aMasterstudent,SchoolofCivilEngineering,ChangshaUniversityofScienceandTechnology,

Changsha410114,China,e-mail:[email protected]

bIntermediateengineer,HunanAcademyofBuildingResearch,Changsha410000,China,e-


For a complex failure equation(e.g. implicit and highly nonlinear), the accuracy of the

conventionalresponsesurfacemethodislimitedbythevariationofrandomvariablesandthe

numberofsamplepoints,whichmayleadtotheinaccuracyofthefittingfailureequationand

theinaccurateapproximatedesignpoint.Therefore,manyimprovedmethodsareproposedto

performreliabilityforlargestructure,andthemultipleresponsessurfacemethodisusedto

fitthefailureequationofthesteelarchstructureinthispaper.Geometricimperfectionswill

significantly reduce the stability bearing capacity of steel arch structure. In order to

reasonablydeterminetheunfavorablegeometricaldefectsofsteelarch,themultipleresponse

surfacesmethodbasedonsubspacedivisionisusedtofitthebearingcapacityfunction.Then,

accordingtotheLagrangemultipliermethodoftheextremumofthefunction,thegeometric

defectsdistributionwiththelowestbearingcapacityissolved.Takingthetwohingedcircular

steelarchasanexample,consideringthechangeofparameterssuchastheloadratioandthe

numberofdeviationnodes,thebearingcapacityanalysisresultsarecomparedbetweenthe

proposedunfavorabledefectsdeterminationmethodandtheconsistentmodeimperfection

method.Theresultsshowthat:(1)Themultipleresponsesurfacesmethodbasedonsubspace

ismoreaccurateinfittingbearingcapacityfunction,andthepredictionvalueofthebearing

capacityisclosetotheresultofthefiniteelementanalysis;(2)Thegeometricimperfections

obtainedbyusingthefittingfunctiontocalculatetheextremumaremoreunfavorabletothe

bearingcapacity,andintherangeofparameteranalysis,thecorrespondingbearingcapacity

isabout10%lowerthanthatobtainedbytheconsistentmodeimperfectionmethod.(3)In

the range of parameter analysis, with the increase of the number of deviation nodes, the

difference between the distribution of unfavorable defects based on multiple response

surfaces bearing capacity fitting and the distribution of the consistent defects is further

increased, and the positive and negative deviations of nodes of unfavorable defects

distributionbasedonmultipleresponsesurfacesbearingcapacityfittingaremoreobvious.



160

A0423- Structural failure pattern recognition and reliability analysis based on

multi-responsesurfacemethod

ZhaoChena,LinjieZhaob



bIntermediateengineer,Henaninstituteofarchitecturaldesignandresearch,Zhengzhou

450014,China,e-mail:[email protected]

In order to prove the correctness of the calculation results of the multi-response surface

methodstructureanalysissoftware,thispaperusesthesoftwaretoanalyzeandcalculatethe

space48-bartransmissiontowerstructure.Theauthorcomparesthecalculatedresultsofthe

software with those obtained by Monte Carlo method, line sampling method and subset

simulationmethod.Itisfoundthatthismethodisveryclosetothesystemreliabilitycalculated

by Monte Carlo method, line sampling and subset simulation. The results obtained by this

programaresatisfactory.Moreover,thenumberofstructuralanalysesrequiredbythismethod

isthelowestcomparedwiththeothermethods,whichonlyneeds228.Thisshowsthehigh

efficiency of this method. The traditional failure pattern recognition and structural system

reliability analysis methods have two shortcomings: the main failure pattern recognition

efficiency is low and the joint failure probability calculation of multiple failure modes is

complex.Inthispaper,animprovedsimulationmethodisproposedtoidentifythemainfailure

modes.Usingthismethodtoaclassicalframestructureisanalyzed,anditiscomparedwith

the more widely used one, namely, beta boundary method. The results show that a large

numberofcomponentsneedtobeanalyzedfortheirreliabilityintheprocessofidentifying

majorfailuremodes.However,thismethodonlyneeds56finiteelementanalysestoobtainthe

samecalculationresults.



161

A0440- IDENTIFICATION OF PERFORMANCE DEGRADATION MODEL BASED ON

STANDARDWIENERPROCESS

XiaoWanga,ZhenhaoZhangb

aPostgraduate,ChangshaUniversityofScienceandTechnology,e-mail:

[email protected]

bAssociateProfessor,ChangshaUniversityofScienceandTechnology,e-mail:

[email protected]

Wienerprocessmodel isakindofcommonprobabilisticstatisticalmodel,whichhasgood

computational analysis characteristics and can describe the degradation process of non-

monotonesystem.Therefore,itisoneofthemostwidelyusedmodelsinstructuralreliability

modelingbasedonperformancedegradation.Furthermore,theengineeringstructurehasthe

characteristics of randomness, fuzziness and time-varying in the service life. Thus, it is

consideredthattheuseofWienerprocesstodescribethedegradationprocessofstructure

can reflect the actual situation of structural degradation better. In fact, identification of

degradationprocessmodelsisthemostimportantanddifficultinthedegradationprocesses

modeling. In this paper, we use auto-correlation function method and hypothetical test

methodtoidentifymodel.Thefirstmethodisempirical,whichissuitableforallcomponents

tomeasureperformancedegradationatthesametimeandlowprecisionrequirement.Firstly,

wedrawtheauto-correlationfunctiongraphofthewienerprocessbyMATLAB.Secondly,we

collectthedegradationdataoftheconcretedynamicelasticmodulusthatcanbeusedasa

parameterofevaluatingdurability,thenobtaintheauto-correlationfunctionofthedataand

supplementitwiththegraph.Finally,wecomparethegraphicsofthetwo,itcanbeseenthat

they are similar in appearance, so we can preliminarily determine that the degradation

processconformstothewienerprocess.Comparedwiththefirstmethod,thesecondismore

reliable,whichusesprobabilitystatisticsmethodtotestwhetherthedegradationofdynamic

elasticmodulusofconcretesatisfiesthedefinitionofWienerprocess.Firstly,weadoptShapiro

testmethodtoexaminethenormalityofthedatabytheR-Studio;theresultsshowthattheW-

valueiscloseto1andtheP-valueisgreaterthan0.05,itexplainsthatthedataobeythenormal

distribution.Besides,weusethelinearregressionmethodtofitmeanandvarianceofthedata

onthisbasis,theresultsisthatthecorrelationcoefficientRofthemean,ut andthevariance,



162

t2 iscloseto1andP-valuenear0,soitisconsideredthatthedegradationdataofdynamic

elasticmodulusadherestoanormaldistributionwithanaverageofut andvarianceof t2 .

Secondly,werespectivelyuseADFtestmethodandLBQtestmethodtoexaminethestability

andindependenceofthedata,theADFresultsreflectthatP-valueislessthan0.05andtheLBQ

resultsdisplaythatP-valueisgreaterthan0.05,itmeansthattheincrementprocessisstable

and independent. In conclusion, we can judge that the concrete dynamic elastic modulus

degradationsatisfiesdefinitionofWienerprocess.Onthisbasis,wecanpredicttheresidual

lifeofthestructureandprovideascientificbasisforthelatermaintenanceandreinforcement

of the structure. In addition, we also can evaluate the reliability of the existing concrete

structuraldurabilityandprovideareasonabledesignbasisfortheproposedstructure,thus

reducetheconstructioncostoftheengineeringstructureatmaximumextentunderensuring

thesafety.



163

A0449- A NeW unbiased metamodel method for Efficient reliability analysis of

structureswithmultiplefailuremodes

GuofengXuea,YongshanZhangb

aPostDoc,SchoolofCivilEngineering,GuangzhouUniversity,e-mail:[email protected]

bProfessor,SchoolofCivilEngineering,GuangzhouUniversity,e-mail:

[email protected]

Asawidelyusedmethodforstructuralreliabilityanalysis,themetmodelmethodcanreduce

the computational cost substantially. However, there always exists error due to the

approximation of the metamodel to the Limit state function (LSF), resulting in a biased

estimator of the failure probability. In order to overcome the difficulties of the metamodel

method,theauthorsdevelopedanunbiasedKrigingmetamodelmethod.Thebasicideaisto

formulate the unknown failure probability as a product of the Kriging metamodel-based

failure probability and a correction term which accounts for the error due to metamodel

approximation.ThecorrectiontermisestimatedefficientlywiththeMarkovchainsimulation

byintroducinganintermediateeventwhichistheunionoftheactualfailureregionandthe

metamodel-based failure region. However, practical engineering structures often have

multiplefailuremodes.It’shardtoobtaininitialsamplesfromthefailureregions,whichmakes

it infeasible to perform Markov chain simulation and estimate the correction term. What’s

more,Markovchainsstartfromonefailureregionhasfewchancestojumptoanotherfailure

region.Therefore,contributionsofdifferentfailureregionstothefailureprobabilitycannotbe

properlyaccountedfor. Inordertotacklethedifficultyoftheunbiasedmetamodelmethod

when applied to problems with multiple failure regions, this paper proposes a modified

versionoftheunbiasedKrigingmetamodelmethod.Theproposedmethodconsistsofthree

steps:1)buildsaninitialKrigingmetamodelwithsuchanaccuracythatthemetamodelcan

capturetheglobalbehavioroftherealLSFs,2)proposesanadaptiveclusteringalgorithmto

obtainrepresentativesamplesfromthefailureregions,basedonthebuiltKrigingmetamodel,

3)estimatesthefailureprobabilitywiththeunbiasedKrigingmetamodelmethod.Thefirst

stepisimplementedbyusingthemetamodelconstructionstageoftheMeta-ISmethod.The

Krigingmodelisadoptedasthemetamodelhere,althoughanyothermetamodelisapplicable.

An intial Kriging metamodel is built with a few samples generated by Latin hypercube



164

sampling(LHS).ThentheKrigingmetamodelisupdatedsequentiallywithsamplesfroman

importance density constructed based on current metamodel. The update process is

conducteduntil thetargetaccuracy isachieved,whichguaranteesthatrelativeerrorofthe

metamodelisintheorderofmagnitudeof1.Ingeneral,themetamodelwithsuchanaccuracy

can capture the major failure regions. Based on the last updated metamodel, an adaptive

clustering algorithm is employed to identify the failure regions. The Davies-Bouldin (DB)

indexisadoptedastheclusteringvalidityindex.ClusteringthatminimizestheDBindexisthe

optimalclustering.Eachclustercorrespondstoasub-failureregion.Andthecluster’centroid

ischosenastherepresentativesampleofeachoneofthefailureregions.Basedontheobtained

samplesofthefailureregions,thecorrectiontermiscalculatedbyMarkovchainsimulation.

Following the procedure of the unbiased metamodel method, the failure probability is

estimated by multiplying the correction term by the metamodel-based failure probability.

Severalnumericexamplesareprovidedtodemonstratetheproposedmethod.



165

A0487- SPARSE PARTIAL LEAST SQUARES REGRESSION-POLYNOMIAL CHAOS

EXPANSIONMETAMODELINGMETHOD

WeiZhaoa,LingzeBub

aLecturer,SchoolofCivilEngineering,HarbinInstituteofTechnology,Harbin,150090,China,


bPhDcandidate,SchoolofCivilEngineering,HarbinInstituteofTechnology,Harbin,150090,

China,e-mail:[email protected]

To circumvent the curse of dimensionality and multicollinearity problems of traditional

polynomial chaos expansion approach when analyzing global sensitivity and structural

reliability of high-dimensional models, this paper proposes a sparse partial least squares

regression-polynomialchaosexpansionmetamodelingmethod.Firstly,aninitialestimationof

polynomialchaosexpansioncoefficientsisobtainedwiththepartialleastsquaresregression.

Secondly,accordingtotheprincipleofmaximumsparsityundertheallowanceofregression

errorthreshold,polynomialswhichhavestrongcorrelationwiththestructuralresponseare

adaptively retained with the penalized matrix decomposition scheme. Next, an updated

estimationofthepolynomialchaosexpansioncoefficientsisobtainedwiththepartial least

squaresregression.Sobolsensitivityindicesareobtainedwithasimplepost-processingofthe

expansion coefficients. Finally, the metamodel is greatly simplified by regressing with

importantinputs,leadingtoaccurateestimationsofthefailureprobabilitywithoutadditional

computational cost. The results show that with acceptable accuracies, the new method

overperformsthetraditionalcounterpartintermsofcomputationalefficiencywhensolving

high-dimensionalglobalsensitivityandstructuralreliabilityanalysisproblems.



166

A0518-GlobaldynamicSeismicReliabilityanalysisforRCFramestructuresUsing

nt-ANN

Da-GangLua,Jia-ShuaiWangb,YanSongc,ZiZhangd

aProfessor,SchoolofCivilEngineering,HarbinInstituteofTechnology,e-mail:

[email protected]

bPhDstudent,SchoolofCivilEngineering,HarbinInstituteofTechnology,e-mail:

[email protected]

cPhDstudent,SchoolofCivilEngineering,HarbinInstituteofTechnology,e-mail:

[email protected]

dPhDstudent,DepartmentofCivilandEnvironmentEngineering,NorthDakotaState


Globalreliabilityofstructuresbasedonsystem-levellimitstatefunctionsisanefficientand

approximate approach to system reliability analysis for complex structures under dynamic

disaster actions. However, the global limit state variable (GLSV) is generally an implicit

functionofthebasicrandomvariables(RVs).Furthermore,thedimensionofthebasicrandom

variablesisanotherbottleneckproblemtothepracticalapplicationsofthisapproach.Monte

Carlosimulation(MCS)andmeta-modeltechniquesaregoodalternativestoovercomingthese

problems.However,MCSaswellasitsdifferentvariantsrequiresubstantialsamplepointsand

costenormouscomputingresourcesforaccurateestimations.Themeta-modelssuchasANN,

alsohavetheproblemofcurseofdimensionality.Inthispaper,anANNmeta-modelbasedon

number-theoreticpoint-selectionstrategy(NT-ANN)isdevelopedtoanalyzeglobaldynamic

reliability analysis of reinforced concrete (RC) frame structures under seismic actions. To

uniformlyfill thespaceofbasicRVsandreducetherequirednumberofsamplepoints, the

goodlatticepointapproachinthenumbertheoryisutilizedtoreplacetheLatinhypercube

samplingapproach.TwogloballimitstatefunctionsforRCframestructuresareconsidered:

globaldeformationlimitstateandglobaldamagelimitstate.TheBPforwardANNsaretrained

asthemeta-modelsforthetwogloballimitstatefunctions.Atwo-sidedevolutionarypower

spectrummodelconsideringthenon-stationaritiesinbothintensityandfrequencyischosen

tomodeltherandomprocessofthestochasticgroundmotion.Furthermore,therandomness

of structures is also considered. Then, the global dynamic reliability indices for the two

system-levelgloballimitstatesofRCstructuresunderseismicactionsarecalculatedbythe

developedNT-ANNmethod.Theaccuracyandefficiencyoftheproposedmethodareverified

andcomparedbythesubsetsimulationtechnique.



167

A0540- Estimating uncertainty in limit state capacities for reinforced concrete

framestructuresthroughpushoveranalysis

Xiao-HuiYua,Da-GangLub

aSchoolofCivilEngineering,HarbinInstituteofTechnology,Harbin150090,P.R.China,e-


bSchoolofCivilEngineering,HarbinInstituteofTechnology,Harbin150090,P.R.China,e-


Inseismicfragilityandriskanalysis,thedefinitionofstructurallimitstate(LS)capacitiesisof

crucial importance. Traditionally, LS capacities are defined according to design code

provisions or using deterministic pushover analysis without considering the inherent

randomnessofstructuralparameters.ToassesstheeffectsofstructuralrandomnessonLS

capacities, ten structural parameters that include material strengths and gravity loads are

consideredasrandomvariables,andaprobabilisticpushovermethodbasedonacorrelation-

controlled Latin hypercube sampling technique is used to estimate the uncertainties in LS

capacitiesforfourtypicalreinforcedconcreteframebuildings.AseriesoftenLSsareidentified

from the pushover curves based on the design-code-given thresholds and the available

damage-controlledcriteria.TheobtainedLScapacitiesarefurtherrepresentedbyalognormal

model with the median mC and the dispersion βC. The results show that structural

uncertainties have limited influence on mC for the LSs other than that near collapse. The

commonlyusedassumptionofβCbetween0.25and0.30overestimatestheuncertaintiesin

LS capacities for each individual building, but they are suitable for a building group with

moderatedamages.AlowuncertaintyasβC=0.1~0.15isadequatefortheLSsassociatedwith

slightdamagesofstructures,whilealargeuncertaintyasβC=0.40~0.45issuggestedforthe

LSsnearcollapse.



168

A0549- Study on Mechanical properties and damage assessment for Collided

Concrete

XY.Liua,GH.Wangb,L.Shenc,andRJLia

aSchoolofCivilEngineering,ChangshaUniversityofScience&Technology,Changsha,


bTheCollegeofCivilEngineeringandArchitecture,HunanInstituteofScienceand

Technology,Yueyang,414000,China,e-mail:[email protected]

cSchoolofCivilEngineering,ChangshaUniversity,Changsha,410022,China,e-mail:

[email protected]

Withtherapiddevelopmentoftransportation,theaccidentsofvehicleshitthesuperstructure

ofbridgeshaveoccurredfrequently.However,theexistingcodesandstandardsdonothave

themechanicalperformanceindexofcollidedconcrete.Atpresent,itisdifficulttoobtainthe

mechanicalpropertiesanddamagedegreeforcollidedconcrete,andthemaintenancedesign

for collided bridges cannot be carried out. In this paper, finite element (FE) numerical

simulation and model tests are employed for assessing the damage degree for collided

concretebasedonAcousticEmission(AE)technology.Firstly,thewholeprocessofcollision

forconcretestandardspecimenissimulatedbyusingthefiniteelementsoftware.Meanwhile,

based on the simulation results, 24 group concrete standard specimens are made and the

concrete falling hammer collision test is conducted with considering different cases. After

comparingtheresultsofcollisionforcetimehistorycurve,stressandpeakstrain.Itisfound

that the values of numerical simulation agree well with the values of model test, and the

correctnessofthenumericalsimulationcanbeverified.Secondly,theAEtechnologyisutilized

for analyzing the damage degree betweencollided concrete and non-collided concrete, the

resultsshowthatthestrengthofcollidedreduceobviously,andthebrittlenesswithangrowth

trend,theabruptchangecharacteristicsofAEcanbeusedtodeterminethestagesofmicro-

crack formation,expansionand destabilization for theconcrete,and thedamagedegreeof

concretecanbereflected.Finally,basedontherelationshipbetweenenergyrateandrelative

stress,thedamagedegreeofcollidedconcretecanbeobtainedaccordingtoderivethedamage

factorforcollidedconcrete.Itcanprovidescientificbasisfordamageassessmentofcollided

concrete.



169

A0558-Anovelmachinelearning‐basedmethodtoprotectmemberbucklingfor

squarepyramidspacegridstructure

Qian.Zhanga,Jianguo.Caib,Jian.Fengc

aPhDCandidates,SchoolofCivilEngineering,SoutheastUniversity,Nanjing210096,China.

E-mail:[email protected]

bProfessor,KeyLaboratoryofC&PCStructuresofMinistryofEducation,NationalPrestress

EngineeringResearchCenter,SoutheastUniversity,Nanjing210096,China(corresponding

author).E-mail:[email protected]

cProfessor,NationalPrestressEngineeringResearchCenter,SoutheastUniversity,Nanjing

210096,China.E-mail:[email protected]

A novel model is proposed to determine whether there is member buckling in the square

pyramid space grid structure under the design load condition based on the supervised

machinelearningclassificationalgorithm.Therandomdefectsofthestructurearegenerated

throughtheMonteCarloprobabilisticdesignmethod,andthestatisticalcharacteristicsofthe

structuraldefectsareassumedtoobeythenormaldistribution.Thenthedisplacementofthe

selectedresponsecharacteristicpointsunderthelowervirtual loadcondition(Load1)and

the members buckling state under the design load condition (Load2) are calculated by

ABAQUS for the defective square pyramid space grid structure. The input-output

correspondencebetweentheresponsepointdisplacementandthememberbucklingstateis

established.Inputandoutputdatasetsareestablishedthroughcalculatingalargenumberof

structural model with different defect levels. Then, Support Vector Machine, Naive Bayes

classificationandNearestNeighborwereusedtoanalyzetheaccuracyofthepredictionmodel.

Lastly, the effects of the position and number of response points and the virtual load

conditions on the accuracy of the prediction model are further analyzed, and the optimal

predictionmodelschemeisobtained.



170

A0580-Anewfractionalmomentequationsmethodfornonlinearvibrationanalysis

RuijingZhanga,HongzheDaia

aHarbinInstituteofTechnology,Harbin150090,China,e-mail:[email protected]

A novel method based on fractional moment equations and copula moment closure is

proposed to approximate the dynamic response of a stochastic nonlinear systems. The

method is behind the concept that probabilistic density function (PDF) of the response is

capableofcharacterizingthefullrandomcharacteristicsofstochasticresponse.Ourapproach

reliesonthederivationofmomentequationsthatdescribethedynamicsgoverningthetwo-

time statistics. These are combined with a non-Gaussian PDF representation for the joint

response-excitation statistics, based on the copula functions. Through the adopted PDF

representation,wederiveaclosureschemewhichinvolvingthefractionalorderstatisticsof

the response and the closure constraint. The dynamics constraint is also derived directly

through the moment equations. The derivation of PDF is based on the maximum entropy

principleinwhichconstraintshavementionedabove.Numericalexamplespresentedinthe

paperillustratethenumericalaccuracyandefficiencyoftheproposedmethodincomparison

totheMonteCarlosimulationmethodandGaussclosureofintegermoment.



171

A0583- A Kriging-HDMR metamodel method for system reliability analysis of

structures

KaixiangZhanga,HongzheDaia

aHarbinInstituteofTechnology,Harbin150090,China,e-mail:[email protected]

Thereliabilityanalysisforrealstructuresthatinvolvemultiplefailuremodesareextremely

complicatedandcomputationalexpensive.Themostchallengingproblemistoidentifysub-

failuredomainsandtoobtainthesample’sinformation.Fromthispointofview,weproposed

anefficientreliabilityanalysismethodforcomplexstructuralsystemsonthebasisofKriging-

HDMRmetamodel.Firstly,thePseudo-MarkovChainsimulationwasemployedtoidentifythe

failuredomains.TheMarkovChainMonteCarlo(MCMC)methodwasthenusedtosimulate

failuresamplesofthesub-failuredomains.Foreachsub-failuredomain,thesamplewhichhas

the maximum PDF among the simulated MCMC samples was selected as the design point.

ThesedesignpointswereemployedasthereferencepointstobuildKriging-HDMRmetamodel

foreachsub-failuredomain,respectively.ByweightedsummingtheKriging-HDMRmetmodel

ofallthesub-failuredomains,aglobalKriging-HMDRmetamodelofthestructuralsystemwas

obtained. Finally, Monte Carlo simulation was used to estimate the failure probability by

callingtheglobalKriging-HDMRmetamodel.Theproposedmethodcansignificantlyimprove

theaccuracyandefficiencyofthereliabilityanalysisofstructureswithmultiplefailuremodes,

whichofferseffectivealternativeforthecommonlyusedmethods.Twonumericalexamples

werepresentedtodemonstratetheproposedmethod.



172

A0613- STUDY ON CORROSION FATIGUE RELIABILITY OF STEEL BOX GIRDER

DETAILSOFCABLE-STAYEDBRIDGEBASEDONNEURALNETWORK

CHENJi-gonga,ZHUXunb

aGraduatestudent,CollegeofCivilandArchitecture,ChangshaUniversityofScienceand

Technology,e-mail:[email protected]

bGraduatestudent,CollegeofCivilandArchitecture,ChangshaUniversityofScienceand


Inthispaper,thecorrosionfatiguebehaviorofsteelboxgirderisstudied.Thedirecteffectof

corrosion and the coupling effect of corrosion and fatigue are considered in the reliability

study.Thecorrosionfatigueproblemoflocalwelddetailsofsteelboxgirderofcable-stayed

bridge isstudied fromthepointof time-varying reliability.Aiming at theproblemof time-

varyingreliabilityevaluationofcorrosionfatigueforlocalwelddetailsofsteelboxgirderof

cable-stayed bridge, the following aspects are studied. Study on time-varying model for

corrosionfatigueresistance,theattenuationlawofsteelstrengthduetocorrosionisobtained

firstly,andthentheinfluencelawofcorrosiononthefatiguestrengthofsteelboxgirderis

determined according to the functional relationship between fatigue strength and steel

strength.Onthisbasis,thetime-varyingmodelofcorrosionfatigueresistanceisestablished

accordingtomathematicalstatisticstheory.Forthestudyoftime-varyingmodelofcorrosion

fatigueload,thevariationlawofcorrosiondepthofsteelboxgirderwithtimeisdetermined

firstly,thenthedimensionparametersaremodifiedinthefiniteelementmodelaccordingto

thetime-varyinglawofcorrosiondepth,andthenthetime-varyingstressamplitudeofsteel

boxgirderiscalculatedbasedontheappliedtime-varyingloadofautomobilefatigue.Onthis

basis, according to mathematical statistics theory, the corrosion fatigue load time-varying

modelisestablishedthroughuniformdesignandneuralnetworktechnology.Forthestudyof

time-varying reliability of corrosion fatigue, the explicit function expression of the time-

varying model of corrosion fatigue resistance and load is determined firstly. The explicit

function expression of the time-varying model of corrosion fatigue resistance is obtained

according to the modification of corrosion function to fatigue strength. According to the

response surface regression, the explicit expression for the time-dependent model of

corrosionfatigueloadingisobtained.Thenthetime-varyingfunctionofcorrosionfatigueis



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established by explicit function expression of time-varying model of corrosion fatigue

resistanceandload,andthetime-varyingreliabilityindexofcorrosionfatigueiscalculatedby

FORMmethod.Finally,takingSutongBridgeastheresearchobject,thetime-varyingreliability

analysisofcorrosionfatiguereliabilityofwelddetailsofsteelboxgirderofcable-stayedbridge

is carried out by using the method proposed in this paper, and the sensitivity analysis of

parametersiscarriedout.Throughtheaboveresearch,thetime-varyingmodelsofcorrosion

fatigue resistance and load effect are established, and the expressions of corrosion fatigue

resistanceandloadeffectinthecalculationofcorrosionfatiguetime-varyingreliabilityare

established.Amethodoftimedependentreliabilityanalysisofcorrosionfatigueformembers

of steel box girder of cable-stayed bridge is presented. The proposed theory, method and

algorithm are applied to the actual bridge engineering. The factors affecting the corrosion

fatiguereliabilityofsteelboxgirderofcable-stayedbridgeareanalyzedquantitativelyandthe

sensitivityofparametersisanalyzed.Thetrendanalysisofcorrosionfatigueperformanceof

steelboxgirderofcable-stayedbridgeisgivenrespectively.



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A0644-ANewANALYTICALApproachforSolvingtheFirst-PassageProbabilityof

theContinuousMarkovProcess

ZhenhaoZhanga,MingFangb

aAssociateprofessor,ChangshaUniversityofScienceandTechnology,e-mail:

[email protected]

bPostgraduatestudent,ChangshaUniversityofScienceandTechnology,e-mail:

[email protected].

The analysis of first-passage probabilities in stochastic processes is a key problem in the

evaluationofstructuralreliability.Inthiswork,thecontinuousMarkovprocesswasstudiedin

detail to obtain new methods for solving its first-passage probabilities. First of all the

conventional Poisson process method was used to analyze the first-passage probability of

continuousMarkovprocessanditwaspointedoutthatPoissonprocessmethodcannotsolve

thefirst-passageproblemofageneralcontinuousMarkovprocess.ThentheMarkovproperty

of the continuous Markov process was used to calculate the first-passage probability of a

continuous Markov process. This new method includes the following analysis steps. First

integrate the transition probability density function of the Markov process to obtain the

transitionprobabilitydistributionfunction.Thenbasedonthetotalprobabilityformulaand

the transition probability distribution function, the relation of the probability distribution

functionofthefirst-passagetimeoftheMarkovprocessandtheonedimensionalprobability

distributionfunctionoftheMarkovprocesscanbeobtainedbymathematicaldeduction.And

theonedimensionalprobabilitydistributionfunctionofcontinuousMarkovprocesscanbe

obtainedthroughthetransitionprobabilitydensityfunctionandtheinitialconditionofthe

Markovprocessbyintegration.Thustheprobabilitydistributionfunctionofthefirst-passage

time of the continuous Markov process can be solved finally, by which the first-passage

probability canbecalculatedeasily. Theresults indicate that analyticalexpressions for the

first-passagetimeprobabilitydistributionfunctionofthecontinuousMarkovprocesscanbe

derivedusingelementarymathematicalmethods,throughtheMarkovpropertyoftheprocess.

Theresultinganalyticalsolutiondoesn’trequiretheuseofassumptionsinitscalculations.The

new analytical method based on the Markov property of the continuous Markov process

produceshighlyaccuratesolutions.Finally,asanapplicationexample,acontinuousMarkov

processwasusedtosimulatestructuralperformancedegradation.Itisusedtorepresentthe

time-varying amount of structural degradation at any point in time, leading to a non-

stationarystochasticmodelforthedegradationprocess,whichwillprovidesascientificbasis

foranestimationofthestructuraldurabilityandreliabilityofconcrete,andtheformulationof

arationalfortificationandmaintenanceschemesforconcretestructures.



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A0753- A polynomial element based Galerkin approach for the simulation of

multivariaterandomfields

XufangZhanga,QianLiu,HeHuang

aAssociatedProfessor,SchoolofMechanicalEngineeringandAutomation,Northeastern


Uncertaintysimulationsrelatedtospatiallyvaryingrandompropertiesrequirethetheoryof

randomfielddiscretization.Itisknownthatarandomfieldindefinitionconsistsofaninfinite

numberofrandomvariablesthatareattachedtoeverypointof thesimulationregion.The

utilityofKarhunen-Loève(K-L)expansionallowsonetorepresent therandomfieldas the

summationofaseriesofdeterministicfunctions.Bythisway,statisticalapproximationofthe

spatially varying random property can be realized by means of a finite number of random

variables.However,theK-Lexpansiondependscruciallyuponanalyticaleigen-solutionsofthe

Fredholmintegralequationofthesecondkind.Especiallywithanemergingrequirementfor

a multivariate random field simulation along with complex geometries, the exact K-L

expansionisseldomapplicableforrealisticengineeringproblems.Tothisend,apolynomial

element based Galerkin approach is introduced in the paper to deal with the integral

eigenvalue problem for complex geometries. To implement, various types of high-order

elementsarederivedbasedonorthogonalpolynomialsinnumericalanalysis.Besides,todeal

withhigh-dimensionalintegralsproducedbythemultivariateGalerkinprojection,theGauss-

type numerical interpolation schemes are presented to approximate the true but

computationally demanding covariance functions. To access numerical accuracy of the

polynomialelementbasedGalerkinapproach,theconvergencerateisassessedbymeansof

global variance and covariance errors. Several examples including the reproduction of

spatially varying fiberglass density field along with the NACA0012 airfoil geometry are

presentedtoillustrateengineeringapplicationsoftheGalerkinapproach.Resultshaveshown

the polynomial element based Galerkin method is effective for numerical simulation of

multivariaterandomfieldsalongwithcomplexgeometriesinvariousengineeringdomains.



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A0771-ConstructionMonitoringfortheHeavyTrussLiftingProject inChangsha,

China

PeiYilina,ZhouSaib,ZhaoYuc

aHunanUniversity,HunanChangsha,China,e-mail:[email protected]

bHunanUniversity,HunanChangsha,China,e-mail:[email protected]

cHunanUniversity,HunanChangsha,China,e-mail:[email protected]

The under constructed Ice-snow Joy World project in Changsha is the largest indoor

amusementparkamongtheworldwhichwasalsotheonlypublicstructurewiththeice-snow

themethatconstructedabovethediscardedhugepit.Theglobalstructureiscompositedby

the 60-m mass concrete supporting columns, the 3×104 -m 2 concrete platform and the

1.8×104-tonsteeltrussroof.Aliftingprojectwasinitiatedtobuildtheroofsystemwhichwas

constructedbythelarge-spantrusseswithhugeself-weight,andthelargecomponentcross-

sectionshasleadingagreatweldingoperationsfortheliftedstructures.Thefirstlylifted600-

tonprimarytrusswasapproximately48-mlong,8-mdeepandwasweldedbytheseriesof

thin-walledboxsteel,whichwasliftedbyfourgroupssteelcablesinsidethesteeltubes.The

integralliftingprocesswasplannedtocompletefor27mhoistingheightwithin6hours.To

evaluate the operation risk and require the practical demands of structure performance

during the construction process, a real-time remote monitoring system with 10-mins

sampling time was designed and implemented to measure the stress status of structural

components. The multiple vibratory-wire strain gauges were deployed in this project to

measureandmonitorthestressesindifferentlocations,wheretengaugeswerearrangedin

the primary truss and eight gauges were arranged at the bottom for each of the two-side

supporting columns with distributed data-acquisition equipment to measure the strain

releasesduringtheconstructionprocess.Theactualtestedstrainmeasurementsshowedthat

theprimarytrussexhibitedtheacceptablelevelsofstrainthatwerebelowsteelyieldinglimits,

whichindicatingthatasafestatuswasperformedbythestructureduringtheliftingprocess.

Andthestressstatusoftwo-sidesupportingcolumnswereconsistentlykeptinacertainrange,

which indicating that a stable lifting operation was investigated without larger tilt and

vibrationorabnormalconditions.Andtheout-of-planemovementswasnotoccurredduring

theliftingprocess.Minorchangesofstressconditionswereinvestigatedfortheprimarytruss

duringthesubsequentboundaryweldingoperation,whilethestressinsupportingcolumns

was continuously diverged within an acceptable range until the welding operation was

completed. The measured stress distribution characteristics was confirmed by the finite

element(FE)modeltoensurethattheconstructionbehavioroftheprimarytrusssystemwas

reliableduringtheglobalprocess.



177

A0830-QuantifyingPost-disasterFunctionalityLossesandRecoveryofCommunity

BuildingPortfolios

PeihuiLina,NaiyuWangb

aPost-doctoralresearcher,SchoolofCivilEngineeringandEnvironmentalScience,University

ofOklahoma,USA,[email protected]

bAssistantProfessor,SchoolofCivilEngineeringandEnvironmentalScience,Universityof

Oklahoma,USA,[email protected]

Assessingcommunityresiliencerequiresestimationofpost-disasterfunctionalitylossesand

recovery of its building portfolios. This study proposes a physical-based probabilistic

framework for quantifying the functionality loss and recovery of spatially distributed

buildings within a community, as an integrated system. The framework includes three

modules:(1)First,anovelbuildingportfoliofunctionalitymetric(BPFM)isproposed,which

isameasurable,scalable,andactionableindicatorofabuildingportfolio’scapacitytorespond

and recover from a hazard event. (2) Second, a building portfolio loss estimation (BPLE)

approachisdevelopedtoquantifythefunctionalitylosses(measuredbyBPFM)ofbuilding

portfolios immediately following the hazard probabilistically, by propagating uncertainties

throughouthazardcharacterization,spatialdamageevaluation,andspatialfunctionalityloss

estimation. (3) Third, conditional on the functionality losses quantified in previous step, a

buildingportfoliorecoverymodel(BPRM)isdeveloped.TheBPRMisatwo-levelstochastic

simulation model modeling the building-level restoration as a discrete state continuous

timeMarkovChain(CTMC)andmodelingtheportfolio-levelrecoverybyspatialaggregation

oftheindividualbuilding’sCTMCprocessovertheentirerecoverytimehorizon.Intheend,

theentire frameworkis implementedtoatestbedcommunity—ShelbyCounty,TN,under

scenarioearthquakehazard.



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A0912- Analytical solution for local buckling strength of square CFT columns

subjectedtoeccentriccompression

LONGYu-linga,WANJunb

aAssociateprofessor,DepartmentofCivilEngineering,GuangdongUniversityofTechnology,


bGraduatestudent,DepartmentofCivilEngineering,GuangdongUniversityofTechnology,e-


Intheresearchanddesignoflocalbucklingofconcretefilledsteeltubular(CFST)members,

thelocalbucklingcharacteristicsofcircularorsquareCFSTmembersunderaxialcompression

are studied. However, the theoretical and experimental studies on the local buckling

characteristics of CFST members under eccentric compression have not been reported. In

engineering practice, concrete filled square steel tubular columns are widely used as

eccentricallyloadedmembers,andthelocalbucklingcharacteristicsofthesteeltubewallare

notclear.Inthispaper,thelocalbucklingbehaviorofthesteeltubeofconcretefilledsquare

steeltubulareccentricallyloadedcolumnsisstudiedtheoretically.Itisassumedthatboththe

loaded and non loaded edges of the square steel tube columns are fixed constraints, and

consideringtheeffectofconcretefilledinthesteelsheet,thatis,assumingtherigidityofthe

concretefilledinthesteelsheet,thesteelsheetcanonlybuckleoutward.Takelongitudinal1.5

wave(wavelengtha)forresearch,ananalyticalsolutionoflocalbucklingstressofconcrete

filled square steel tubular eccentrically loaded columns is derived by means of energy

variationalmethod.Furthermore, it is foundthat the localbucklingstrengthσcrdecreases

significantly with the increase of width-thickness ratio b/t when the stress gradient is

constant,andthelocalbucklingstressincreaseswiththeincreaseofstressgradientwhenthe

width-thickness ratio is constant. When the stress gradient coefficient is 0, that is, axial

compression, the local buckling coefficient of the steel tube reaches the minimum value of

10.312; when the stress gradient coefficient is 2, that is, pure bending, the local buckling

coefficient of the steel tube reaches the maximum value of 22.713. When concrete-filled

squaresteel tubularcolumnsaresubjectedtouniaxialeccentric loading, the localbuckling

strengthofeachsteelplateofconcrete-filledsquaresteeltubularcolumnsisdifferentbecause

of thedifferentstressstate. Inorder tomaximize theuseof thestrengthofconcrete-filled



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squaresteeltubularcolumns,thelocalelasticbucklingshouldbeavoidedbeforethesteelyield,

theconcrete-filledsquaresteeltubularplatescriticallocalbucklingstressisgreaterthanits

yield strength. Finally, the reasonable width-thickness ratio limits of each steel plate of

concrete filled square steel tubular eccentrically compressed columns with different stress

gradientcoefficientsaregiven.Satisfyingthelimitscanensurethatnolocalelasticbuckling

occursbeforethesteelplateyields,whichcanbeusedasareferenceforengineeringdesign.



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A0915-RiskPrioritynumbersforvariousfailuresinbridges

ChandrasekharPutchaa,JessicaRodriguezb,SubhrajitDuttac

aProfessor,DepartmentofCivilandEnvironmentalEngineering,CaliforniaStateUniversity,

Fullerton,Fullerton,CA92834,USA,e-mail:[email protected]

bGraduatestudent,DepartmentofCivilandEnvironmentalEngineering,CaliforniaState

University,Fullerton,Fullerton,CA92834,USA,

cAssistantProfessor,DepartmentofCivilEngineering,NationalInstituteofTechnoogyat

Silchar,Silchar,Assam,India

Oneoftheimportantandasystematicmethodthatisusedforidentificationoffailuresofany

systemisFMEA(FailureModeEffectsAnalysis).Thisisdonethroughidentificationofthemost

important causes of all the failure modes of the system under consideration. This

identificationcanbeeasilyachievedthroughthedescriptionofallfailuremodesofthesystem

underconsideration.FMEAisbasedontheconceptsofprobabilisticanalysis.Acorresponding

equivalentdeterministicmethodhasbeendevelopedbyDytczakandGinda(2017).Thispaper

describesindetailtheapplicationofthismethodtobridgefailures.Basedonactualdata.The

results are also compared with those obtained using the well known FORM (First Order

Second Moment) method. This will enable the engineers to rank various failures and take

necessarysteps tomitigate therisk.Theseresultswillbeuseful tobothacademicians and

practicingengineers.



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A0944-Reliabilityanalysisofseismiccapacityofshearwallconsideringpossible

tensionfailureandrandomeccentricity

YanbiaoWanga,YouhuaZhaob,YoubaoJiangc



bMasterstudent,SchoolofCivilEngineering,ChangshaUniversityofScienceandTechnology,


cProfessor,SchoolofCivilEngineering,ChangshaUniversityofScienceandTechnology,


In2010Chileearthquake,itisfoundthatsomeRCshearwallstructureshavebeenseriously

damaged, which necessitates great significance to study reliability of the structures.

Consideringthefactorsofflange,abdominalreinforcementareaandrestrainededgemembers,

theseismiccapacityreliabilityindexisanalyzedfortypicalshearwallstructures.Firstly,we

usedPKPMandETABSsoftwaretoestablishtypicalshearwallstructuresof15and33stories,

and analyzed the ranges of the load effect ratio values of rectangular section and I-section

shearwallmodelsunderdifferentseismicintensity.Then,theMonteCarlomethodisusedto

calculatereliability indexforshearwallstructureswithdifferentparameters(e.g.sections,

load effect ratios, reinforcements) considering possible tension failure and random

eccentricity.Theinfluencesofrestrainededgemembersofdifferenttypesonreliabilityare

also analyzed. The results show that: (1) the reliability will reduce by increasing the axial

compressionratiofortheshearwallunderthesamedesigneccentricity;(2)thereliabilityof

shearwallwithrestraintofendcolumnisthehighest,andthatwithrestraintofconcealed

column is the lowest; (3)the vertical distributed reinforcements of the shear wall and the

reinforcementsattheendoftheflangewallhaveagreatinfluenceonthereliability,andthe

reliabilityindexoftheshearwallcanbeimprovedlargelybyincreasingtheareaoftheend

reinforcements.



182

A0949- Structural failure mode identification and reliability analysis based on

multi-responsesurfacemethod

ZhaoChena,LinjieZhaob



bIntermediate engineer,Henaninstituteofarchitecturaldesignandresearch,Zhengzhou


In order to prove the correctness of the calculation results of the multi-response surface

methodstructureanalysissoftware,thispaperusesthesoftwaretoanalyzeandcalculatethe

space48-bartransmissiontowerstructure.Theauthorcomparesthecalculatedresultsofthe

software with those obtained by Monte Carlo method, line sampling method and subset

simulationmethod.Itisfoundthatthismethodisveryclosetothesystemreliabilitycalculated

by Monte Carlo method, line sampling and subset simulation. The results obtained by this

programaresatisfactory.Moreover,thenumberofstructuralanalysesrequiredbythismethod

isthelowestcomparedwiththeothermethods,whichonlyneeds228.Thisshowsthehigh

efficiency of this method. The traditional failure pattern recognition and structural system

reliability analysis methods have two shortcomings: the main failure mode identification

efficiency is low and the joint failure probability calculation of multiple failure modes is

complex.Inthispaper,animprovedsimulationmethodisproposedtoidentifythemainfailure

modes.Usingthismethodtoaclassicalframestructureisanalyzed,anditiscomparedwith

the more widely used one, namely, beta boundary method. The results show that a large

numberofcomponentsneedtobeanalyzedfortheirreliabilityintheprocessofidentifying

majorfailuremodes.However,thismethodonlyneeds56finiteelementanalysestoobtainthe

samecalculationresults.



183

MS15: Environmental Effects on the Properties of

Cementitious Materials: Experiments, Modeling and

Simulation

A0526- Experimental Research on Dynamic Characteristics of Crumb Rubber

ConcreteatLowTemperature

GangXUEa,Mei-lingCAOb,XiaoYIc

aPh.D.,Professor,InnerMongoliaUniversityofScienceandTechnology,China,e-mail:

[email protected]

bInnerMongoliaUniversityofScienceandTechnology,China,e-mail:[email protected]

cInnerMongoliaUniversityofScienceandTechnology,China,e-mail:[email protected]

Therubberconcretecaneffectivelyusethewasterubber.Combiningthepulverizedrubber

powder into the concrete can significantly improve its toughness, crack resistance, heat

insulation, noise reduction performance, impact resistance and energy dissipation

performance.Insomehigh-altitudeandcoldregionsofChina,therearemanyairportrunways,

highways, roadbed sleepers and bridge pier, which are subjected to various loads at low

temperature. Systematic study on the dynamic properties of rubber concrete at low

temperatures is urgently needed and will promote the engineering application of rubber

concrete. In the past few years, we carried out some experimental study and theoretical

analysisofthedynamiccompressionperformance,impactresistanceandenergydissipation

performanceofconcretespecimenswithtworubberparticlesizesandfourrubbercontents

atlowtemperaturesof-30°C,inordertoprovideabasisfortheapplicationofrubberconcrete

inpavementengineeringincoldareas.Themainresearchworkofthisarticleisasfollows:

Thedynamiccompressivepropertiesoflowtemperaturerubberconcreteunderthreeloading

rateswerestudied.Thedynamiccompressivestrengthanddeformationpropertiesofrubber

concreteincreasewiththeincreaseofstressrate,andtheyarehigheratlowtemperatureof-

30°Cthanthoseofnormaltemperatureat25°C.Andtheincreaseofstrengthisrelatedtothe

temperature.Thedynamicincreasefactorofrubberconcreteatlowtemperatureislowerthan

that at normal temperature, which shows that the sensitivity of rubber concrete at low

temperatureislower.Withtheincreaseofrubbercontent,thedynamiccompressivestrength



184

ofrubberconcretedecreasesandthedeformationperformanceincreasescontinuously.And

the deformation of rubber concrete at low temperature is greater than that at normal

temperature.Moreover,withthedecreaseofrubberparticlesize,thedynamiccompressive

strength of rubber concrete decreases, and the deformation slightly increases. The impact

resistanceofrubberconcreteunderlowtemperatureconditionswasstudied.Comparedwith

roomtemperature,Theinitialandfinalcrackingtimesandductilityindiceofrubberconcrete

at low temperature have a certain degree of decrease. The decrease magnitude of rubber

concrete is smaller at low temperature, and the failure process also becomes smooth,

indicating that the mixing rubber powder into concrete has significant role in improving

ductility at low temperature. Regardless of temperature, the difference between the initial

crackandthefinalcrackisthelargestwhentherubbercontentreaches20%.Theductility

indexofconcretespecimenswith20meshrubberpowderisgreaterthanthatofconcretewith

50meshrubberpowder.Whentheconcreteisincorporatedrubberpowderwithparticlesize

of20meshandcontentof20%,theimpactresistanceofrubberconcreteisthebestatlow

temperature.Becausethediscretenessofdataonimpactresistanceofrubberconcreteatlow

temperature,theWeibulldistributiontheoryisintroducedtostudythedistributionlawofthe

numbersofimpact.TheresultsshowthatWeibulldistributiontheorycanbetterdescribethe

distribution rule of rubber concrete impact times well. The low-temperature energy

performanceofrubberconcretewasstudied.Afterthelowtemperature,thehystereticcurve

ofrubberconcretetendstobefull,andtheenergyperformanceincreasessignificantly.With

theincreaseofthemagnitudeofloadingforce,thelossfactorofrubberconcreteincreases,

andtheincreaserateoflossfactorofrubberconcreteatlowtemperatureissmallerthanroom

temperature.Andwiththeincreaseofrubbercontent,thetotalhystereticenergyconsumption

growth rate of rubber concrete at low temperature of -30°C is faster than that of room

temperature25°C.The loss factorofrubberconcretewith largeparticlesize is largerthan

smallparticlesize.Andgreaterrubbercontentresultsinthemoresignificantrateofincrease

oflossfactor.



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A0542- Engineering application of rubber concrete in airfield pavement and its

performance

XiaoYia,GangXueb

aMaster,SchoolofCivilEngineering,InnerMongoliaUniversityofScienceandTechnology,

Baotou,China,e-mail:[email protected]

bProfessor,SchoolofCivilEngineering,InnerMongoliaUniversityofScienceandTechnology,

Baotou,China,e-mail:[email protected]

In order to explore the engineering application of rubber concrete in airfield pavement,

contrastexperimentsonpavementswithordinaryconcreteandrubberconcretewerecarried

outinNingxiaprovinceofChina.Basedontheresultsoffourexperimentaltestsondamping,

impact resistance, temperature susceptibility and impermeability, rubber concrete shows

better performances than ordinary concrete. The average attenuation ratio and average

dampingratioofrubberconcreteis1.5timesand1.6timesthevalueofordinaryconcrete,

respectively. The lower failure destruction degrees of rubber concrete in the free fall test

showedthebetterimpactresistance.Andthegoodthermalstoragecapabilityandsuperior

deformability were observed in the test of temperature susceptibility. What’s more, the

seepageofordinaryconcreteis3.4timesthevalueofrubberconcretewithin40minutes.In

theexpeditiousfreeze-thawexperiment,after300freeze-thawcycles,thelossofqualityand

relativedynamicmodulusofrubberconcretemetthestandardrequirements.Moreover,the

relative dynamic elastic modulus of rubber concrete is 8.6% higher than that of ordinary

concreteafter300freeze-thawcycles.Alltheadvantagesofrubberconcretearebeneficialto

the applicability of the airport pavement, and it is expected to improve the anti-attack

capabilityoftheairportpavementandenhanceitsprotectionandsafetycapabilities.Italso

solvestheproblemoffreeze-thawdamageofcementconcretepavementinhighaltitudeareas,

andcanmeettheurgentneedsofourcountrytobuildairportpavementsinhighaltitudeareas

oftheplateau.



186

A0774-STRAINMONITORINGINCONSTRUCTIONOFLARGE-SCALEREINFORCED

CONCRETEPLATFORM

SaiZhoua,YilinPeib

aCollegeofCivilEngineering,HunanUniversity,Changsha,China,e-mail:

[email protected]

bCollegeofCivilEngineering,HunanUniversity,Changsha,China,e-mail:

[email protected]

TheIce-snowJoyWorldinChangshawasbuiltontopoftheabandonedpit,inwhichthirty-

three concrete-filled steel tube columns were distributed to support the global structural

weightandthereinforcedconcreteplatformwasconstructedtobearvarioustypesofloads.

The long-span platform with an area of 3×104 -m2 was composed of the cast-in-place

prestressedboxconcretebeams,I-beamsandthesteeltrussfloor.Sincethestructuredead-

weight is considerably heavy and the engineering has long construction period, it is

indispensable to carry out long-term strain monitoring on the complex platform structure

during the construction process of the Ice-snow Joy World, in particular the multi-span

continuousgirderbeamswithasectionheightof5m,onwhichexternalforce,deformationor

temperaturestressmayhavesignificantinfluencestocauseadditionalinternalstress.Astrain

monitoringschemewasdesignedandthemeasurementstationsweremainlyarrangedinthe

partswithlargedeformationandsensitivitypredictedbytheoreticalcalculation.Theretotally

contains196strainsensorspre-embeddedinthemainbeamstoobtainaseriesofstraindata

as well as the temperature for monitoring the dynamic status of the structure under

constructionandforfurtherstudies.Thebeamstrainmonitoringsystemcontributestoknow

about the invisible tiny deformation of the components and infer the stress state and

mechanical characteristics along with time change and varying environment. Besides,

temperature sensors were layout in the mass concrete volumes to observe the inner

temperaturedifferences,whichwasaimedtoavoidcriticalcracksduetothesignificantstress

gradienteffectduringcasting.Afteraperiodofdatacollectionandanalysis,someconclusions

canbedrawnfromtheintuitivestrainandtemperaturecurves,whichreflectedtheresulting

stress changes of individual beam under construction and service, and it revealed the

connectionbetweenthestressfieldandtemperaturefieldofmassconcretestructures.Fora



187

validationofthereliabilityofthestrainmonitoringsystemandstructuralsafetyperformance,

simulationcomputationusingafiniteelement(FE)methodwascarriedouttocomparethe

peakstrainsbetweenthemeasuredvalueandthesimulationresultduringtheconstruction,

andthemeasuredvaluewasconsistentlywithinadmissiblestress indifferentconstruction

stages,indicatingthatthedesignrequirementwasachieved.Therefore,thestructurestrain

monitoringcaneffectivelyinspectthereal-timestateofstressonsiteandevaluatethesafety

of the structure under construction and service condition, providing basis for practical

constructionandengineeringdesign.



188

A0805-STOCHASTICDYNAMICALBEHAVIORSOFCONCRETEREACTIONSYSTEM

INCONCRETESUBJECTEDTOEXTERNALSULFATEATTACK

Tao.Lia,Zhongmin.Suna

aSchoolofEnvironmentandArchitecture,ShanghaiUniversityforScienceandTechnology,

Shanghai200093,China,e-mail:[email protected]

A numerical methodology is proposed in this article to investigate the stochastic dynamic

behaviorsofthecorrosionreactionsysteminconcreteundersulfateattack.First,weprovide

anin-depthdiscussionofthechemicalLangevinequationforelementaryreactionsandthe

deterministicrateequationforcompositereactions.Then,thechemicalLangevinequationfor

compositereaction(CLE-CR)isderivedaccordingtothelawofmassconservationandrandom

processtheory.Thestochastickineticequationforcorrosionreactionsinconcreter(SKE-CRC)

subjectedtosulfateattackisproposedbyapplyingtheCLE-CRtoaseriesofactualsulfate-

induced corrosion reactions. The developed SKE-CRC incorporates the randomness from

systemparameters,initialconditions,andinternalnoiseintothecorrosionreactionsystem.A

seriesofexperimentsareperformedtovalidatetheeffectivenessoftheproposedmethod.The

results calculated from extensive stochastic simulations are expressed in terms of the

likelihoodandextentoftheconcentrationofcorrosionproducts.Theexperimentalresultis

onlyonepossibleoutcomeoftherandomevent,andithasacertainprobability.Theresultsof

thisstudyindicatethatthedynamicalbehaviorsofthecorrosionreactionsysteminconcrete

canbecomprehensivelydescribedifareliableprobabilisticapproachisemployedinsteadof

conventionaldeterministicapproaches.



189

A0812-STOCHSTICMODELINGOFSULFATEIONDIFFUTIONCOEFFICIENTATTHE

CONCRETE-SOLUTIONINTERFACE

Tao.Lia,Shanshan.Wanga



Astochasticmodelofsulfateiondiffusioncoefficientundermultiplefactorsisproposedinthe

paper.BasedonFick'ssecondlaw,theeffectsonthediffusionprocessfromporosity,water-to-

binderratioandstressratioofconcretearecomprehensivelydiscussed.Thecalculatedresults

are compared with the experimental data in the literature. The analysis results of the

stochastic model fit well with the experimental data. This indicates the rationality and

reliabilityof themodel.Comparedwiththeconventionaldeterministicdiffusioncoefficient

model,thestochasticmodelcanreflecttheevolutionprocessofthediffusioncoefficientwith

differentconditions.Andtheprobabilitydensityfunctions(PDFs)ofthediffusioncoefficient

at the different times can be obtained conveniently. In addition, it is also shown that the

randomness of the coupling effect of sulfate and external load essentially comes from the

microstructure porosity affecting its macroscopic diffusion process. Therefore, the random

distribution of porosity can be treated as the main factor considered in the proposed

stochasticmodelofsulfateiondiffusioncoefficient.



190

A0814-SELF-HEALINGOFENGINEERINGGEOPOLYMERCOMPOSITESWITHFLY

ASHANDMETAKAOLIN

Li-li.Kana,Bei-bei.Duana,Tao.Yanb



bSchoolofNavelArchitecture,Ocean&CivilEngineering,ShanghaiJiaotongUniversity,


Self-healingcharacteristicsandmechanismofEngineeredGeopolymerCompositesusingfly

ashandmetakaolin(MFA-EGC)atvarioustensilepreloadingsof1.0%,2.0%and3.0%exposed

toairandwet/drycyclesconditioningregimeswereexperimentallyinvestigated.Theresults

showthatMFA-EGCcombinestheadvantagesoftraditionalECCandgeopolymer,exhibiting

obviousmultiplecrackingpatternandastrain-hardeningbehavior.Thecrackspacingranges

from2mmto5mmandthemaximumresidualcrackwidthisbelow25μm,whichprovidemore

favorableconditionsforself-healing.Afterrehealedsubjectedtotwoenvironments,number

of cracks decreased significantly. The average tensile strain capacity measured can exceed

3.8%,andbothultimatetensilestrainandstrengthofthemajorityspecimensatreloadingare

higherthanthatofvirginspecimenswithoutanypreloading.Airconditioningencouragesthe

self-healing of the MFA-EGC materials. Amorphous aluminosilicate phases with gel-shape

resultingfromgeopolymerizationreactionareverifiedasmainself-healingproductgrowing

inthecrackandPVAfibersurfacebySEM-EDS,XRDandFT-IR,whichmaybeenhancedthe

bondoffiberandmatrixinterface,leadingtotherecoveryofthetensileproperties.



191

A0817- PREPARATION AND CHARACTERISTICS OF PVA FIBER REINFORCED

ENGINEERINGED GEOPOLYMER COMPOSITES INCORPORATING METAKAOLIN

ANDFLYASH

Li-li.Kana,Wen-song.Wanga,Jiahao.Wana



Underactivatingbyalkalinesolutionpreparedbysodiummetasilicateandsodiumhydroxide,

thepreparationofEngineeredGeopolymerCompositesusingflyashasthemainrawmaterial

and metakaolin as auxiliary material was studied, and the performance of uniaxial direct

tensileandcharacteristicof thegeopolymerwerealsoexplored.Theresultsshowthat the

geopolymer has good multi-cracking behavior after uniaxial direct tensile test. The

distribution of cracks is uniform, and the crack spacing is in the range of 2-5mm, and the

average width of residual cracks is about 25μm. The tensile strength for the optimum

proportionat3d,7dand28dwas3.2MPa,3.7MPaand3.8MParespectively,andthetensile

straincouldbeupto6.8%,6.4%and5.2%respectively.Theorderofinfluenceoffactorson

thetensilepropertieswasasfollows:curingtemperature>metakaolincontent>fibercontent.

Through the three-point bending and the single-crack tensile test, it is shown that the

calculated pseudo-strain hardening (PSH) indexes is consistent with the trend of ultimate

tensilestrainbytheuniaxialtensiletest,whichcanwellexplainthehighductility.Theresults

of XRD, FT-IR and SEM show that a large number of amorphous geopolymeric gel were

producedduringthegeopolymerizationreaction,coveringaroundsphericalflyashparticles,

andthesymmetricstretchingAl-O/Si-ObondsandSi-O-Sibendingbondwereobserved.



192

A0953-Multi-PhaseModellingofMulti-speciesTransportinCementitiousMaterials:

IncaseofElectrochemicalRehabilitation

Qing-fengLIUa,Li-xuanMAOb,ZhiHUc

aAssociateProfessor,StateKeyLaboratoryofOceanEngineering,ShanghaiJiaoTong


bMPhilresearcher,StateKeyLaboratoryofOceanEngineering,ShanghaiJiaoTong


cMPhilresearcher,StateKeyLaboratoryofOceanEngineering,ShanghaiJiaoTong


Existing reinforced concrete structures experience severe durability degradation when

subjected to alkali–silica reaction (ASR) and chloride attack. A special electrochemical

rehabilitationtreatment,containinglithiumcompoundanolyte,hasbeendevelopedtodrive

lithiumionsintoconcreteaswellasremovechloridessimultaneously,formitigatingboththe

ASR-induced cracks and the chloride-induced corrosion. Good performance of introduced

lithiums in controlling ASR-induced expansion has already been proved. Unfortunately, the

migration mechanism of lithium in concrete under an external electric field is seldom

investigated in existing literature. In this study, with help of the “double-multi” model, the

efficiency of impregnation of lithium ions and simultaneously the removal of chloride ions

throughaspecificelectrochemicaltreatmentarenumericallyevaluated,whichresultsintothe

distributionprofilesofalltypicalionicspecies.Theheterogeneousconcretemodelexamines

theaggregateeffect,especiallyontheinteractionwithlithiumswhicharesupposedtomitigate

ASR. The ionic interaction between different species and the electrochemical reaction at

electrodes are also considered. Through a relative thorough modelling of multi-phase and

multi-species,asystemicparametricanalysisbasedonaseriesofsignificantfactorsduring

electrochemical treatment (e.g., current density, treatment time, temperature, cathode

positionandconcentrationof lithiumsolution)revealssomeimportanttendenciesof ionic

electromigrationinconcrete,whicharesupposedtoguidethefieldapplication.



193

A0966-ResearchonMoistureTransportofCement-basedMaterialsBasedonLow

FieldNuclearMagneticResonance

HaitaoZhaoa,XiaWub,YuyuHuangc

aAssociateprof.,HohaiUniversity,e-mail:[email protected]

bPostgraduatestudent,HohaiUniversity,e-mail:[email protected]

cPostgraduatestudent,Hohai University,e-mail:[email protected]

Themicrostructure testofcement-basedmaterialsbasedonNMR is conducted. Under the

conditionsofdifferentwatercementratio,ratioofaggregatetocement,silicafumecontent

andSAPcontent,thevariationofthemostprobableapertureandporosityofcement-based

materialsareresearched.Theresearchshowsthatthemostprobableapertureandporosity

ofsampleswithwater-cementratiosof0.5and0.6increaseby2.22nm,7.16nmand4.56%,

9.09%,respectively.WhenS/Cis1,theporosityofsampledecreasesby3.85%.Theincrease

ofsilicafumecontentcanreducethemostprobableapertureofthesample,butincreasethe

porosity.Whenthesilicafumecontentis5%,10%,theporosityincreasesby2.73%,3.83%

respectively. If thesample isdopedwithSAP, themostprobableapertureandporosityare

increasedwhenthecontentis0.15%,andwhenthecontentis increasedto0.3%,themost

probableapertureandporosityarereducedby4.01nm,1.12%respectively.Itcanbefoundto

playagoodinternalmaintenanceroleinanappropriateamount.Basedonone-dimensional

frequency coding technology, the moisture transfer test of cement-based materials is

conducted.Themoisturedistributioncurvesunderdifferentfactorsareobtainedthroughone-

dimensionalfrequencycodingtests.Itisfoundthatthesilicafumereducesthefluidityofthe

slurry, so the internal distribution of the sample is not uniform, water distribution curve

fluctuates up and down. Absorption height h and water volume per unit area i of sample

increase rapidly first and then slowly with time. The growth trend is consistent with the

variationofporosity.Whenwaterabsorptiontimeis7d,handiofthesampleswithwater-

cementratioof0.6arethelargest,51.97mmand9.48mm3/mm2.Basedontheexperimental

results, key parameter models for water transport are constructed. The models of water

volumeperunitareaandheightofwaterabsorptionunderdifferentfactorsareconstructed.

Basedontheexistingmodel,modelsareestablishedbetweensorptivityS,capillarycoefficient

kandmicrostructure,andtherelationshipbetweenSandkisdiscussed.Itisfoundthatthe

ratiobetweenSandkcanbeexpressedapproximatelyasthetwotimesoftheporosity.The

saturationdistributionandtheBoltzmanntransformationofthemoisturedistributioncurve

are calculated, and then the moisture diffusion coefficient is calculated using the existing

model.Thediffusioncoefficientmodelunderdifferentinfluencefactorsisfinallyobtained.



194

MS16: Fluid-Structure Interactions and Flow-Induced

Motions

A0159- Wind-induced cladding and structural loads on low-rise buildings with

4:12-slopedhiproofs

ShuaiShaoa,YujiTianb,QingshanYangc,TedStathopoulosd

aBeijing’sKeyLaboratoryofStructuralWindEngineeringandUrbanWindEnvironment,

SchoolofCivilEngineering,BeijingJiaotongUniversity,Beijing,China,e-mail:

[email protected]

bBeijing’sKeyLaboratoryofStructuralWindEngineeringandUrbanWindEnvironment,

SchoolofCivilEngineering,BeijingJiaotongUniversity,Beijing,China,e-mail:

[email protected]

cSchoolofCivilEngineering,ChongqingUniversity,Chongqing,China;Beijing’sKey

LaboratoryofStructuralWindEngineeringandUrbanWindEnvironment,Beijing,China,e-


dCentreforZeroEnergyBuildingStudies,DepartmentofBuilding,Civil,andEnvironmental

Engineering,ConcordiaUniversity,Montreal,Canada,e-mail:[email protected]

The characteristics of wind-induced cladding loads on building surfaces were examined

regardingdifferentparametersofroofshapes,buildingplans,horizontaldimensions,etc.A

wind tunnel experimental study for low-rise buildings with 4:12-sloped hip roofs was

performedinasimulatedopenterrainexposureattheBuildingAerodynamicsLaboratoryof

ConcordiaUniversity,Montreal,Canada.Furthermore,finite-elementanalysis,appliedtothe

experimentalpressuredata,wascarriedoutinordertoinvestigatestructuralforcefeatures

formainwindforce-resistingframes.Three-dimensional linearcomputationalmodelswith

andwithoutcladding(bareframes)withdifferentstiffnessratiosandconnectionconditions

of structural members influencing the wind load sharing path were considered. Moreover,

comparisons between cladding/frame loads obtained by using experimentally measured

pressuresandtheircounterpartsevaluatedbyusingAmericanwindloadprovisionsforgable

rectangularroofsindicatesignificantreductions.Thesecomparativestudiesareexpectedto

beinstrumentalforfuturedevelopmentofwindcodeandstandardprovisions.



195

A0442-ApplicationsofImmersedBoundaryMethodsinHydraulicModeling

NingZhang,AdamOlera,SusanRegmia,ArunYadava

aDepartmentofChemical,CivilandMechanicalEngineering,McNeeseStateUniversity

Two immersed boundary methods (IBMs) have been developed for implementing

levees/floodgates and 1-D rivers/streams in hydraulic modeling. The IBMs have been

originallydevelopedinCFDsimulationforflowsovermovingobjectsorobjectswithcomplex

shapes, where the immersed boundaries of the objects do not coincide the grid points. In

regionalscalehydraulicmodeling,becausethegridsizecouldbemuchlargerthanthewidths

ofthelevees/floodgatesandsomeoftherivers/streams,thelocationsoftheleveesandrivers

couldoftenlocatein-betweengridpoints.Itisnotaccurateforthetraditionalimplementation

byplacinghigherorlowerlandelevationsonthegridpointstorepresentthelevee/floodgates

and streams. Therefore, IBM becomes a good candidate for this type of modeling and

simulations.Thanksto theIBM, thestructure in-betweenthegridpointscanbeaccurately

realized, and the new implementation presents some advantages over the traditional

implementation.TheIBMimplementationalsomakesitpossibletosimulationscenariosuch

astheleveecollapsingandbreachingduringthefloods,whichitisdifficult,ifnotimpossible,

forthetraditionalapproachtoachieve.Inthisstudy,thelevee/floodgateandonestreamwere

implementedusingtheIBMs,andthesimulationresultswerecomparedtotheresultsfrom

thetraditionalmethodforvalidation.Severalfloodingscenariosweresimulatedtoinvestigate

theeffectsofstorm-surgefloodtothecoastalwetlands.



196

A0747-NonlinearParametricVibrationAnalysisofRadialGates

SiyuanWua,ZhengzhongWangb

aDoctoralCandidate,StateKeyLaboratoryofDisasterReductioninCivilEngineering,Tongji


bProfessor,ColdandAridRegionsWaterEngineeringSafetyResearchCenter,Northwest

A&FUniversity,e-mail:[email protected]

Inthiswork,basedondynamiccharacteristicsofradialgates,anonlinearvibrationequation

oftheradialgatearmisestablished.Excitationconditionsofprimaryparametricresonance

and subharmonic parametric resonance are obtained by using multiple scales method and

numericalmethod.Theparameteranalysisshowsthat:comparingwithtraditionalcalculation

method of dynamic instability region division, the presented method is more suitable to

analysis of parametric vibration for radial gates as considering the end moment, vibration

duration and amplitude. The vibration amplitudes of arm increase with the increase of its

lengthandexcitationamplitude,aswellasthedecreaseofarminclinationangle.Moreover,

theparametricresonanceiseasiertobeexcitedanditsfrequencybandwidthisbroadened

withtheinitialendmomentincreasing.Sincethevibrationresponseofthearmisinfluenced

bythenonlineartermintheequation,thedampingeffectislimited.Inthefurtherresearchof

vibration reduction control, energy transfer method (e.g. tuned mass damper) should be

adoptedtoachievevibrationreductioncontrol.



197

A0785-ModeinteractionsofDEEP-SEAriserINShearflow

ZhiqiangWUa,YuancenWanga,GuoqiZhanga

aTianjin,SchoolofMechanicalEngineering,TianjinUniversity,e-mail:[email protected]

Vortex-induced vibration (VIV) is the main problem for in-service deep-sea risers. VIV is

essentially a nonlinear, self-excited and self-limited multi-degree-of-freedom resonance

response due to the nonlinearities either in structure or fluid. For example, the lock-in

response,hysteresis,displacementjump,bifurcationandchaos.Thepresentexperimentaland

finiteelementanalysis(FEA)methodscanmeasureandcalculatetheresponsecharacteristics

ofrisersatspecificflowvelocity.However,itisratherdifficulttoinvestigatethecontinuous

change of VIV response of riser in larger velocity ranges. Based on the Van der Pol wake

oscillator model, the VIV cross-flow governing equations of the riser fluid-structure

interactionsysteminshearflowareestablished.ThenthesimplifiedMDOFmodelwith15th-

ordermodesisderivedbyGalerkinmethod.Itsbifurcationdiagramisobtainedbyusingthe

method of Poincaré mapping for the velocity of ocean current in a wide range. The

characteristics of typical response are analysed based on time history, phase diagram,

Poincaré section and frequency spectrum. It is found that there are various phenomena of

modeinteractioninthesystem,including1:3internalresonance,non-internalresonanceand

multistable phenomenon. Such as periodic solution and almost periodic solution coexist,

periodic solution and periodic solution coexist, and almost periodic solution and almost

periodicsolutioncoexist.Thecharacteristicsofthesephenomenahaveimportantreference

valuefordesigningthecontrolleraboutVIV.



198

A0788-SuppressingVortex-Induced-VibrationUsingBroadbandPassiveTargeted

EnnergyTransfers

ZhiqiangWUa,GuoqiZHANG,YuancenWANG

aTianjin,SchoolofMechanicalEngineering,TianjinUniversity,e-mail:[email protected]

The passive and nonlinear targeted energy transfers induced by resonant interactions

betweenasingle-degree-of-freedomnonlinearenergysink(NES)anda2-DOFvortex-induced-

vibration(VIV)modelofacylinderisinvestigated.ItisshownthatpartiallysuppressVIVby

passivelytransferringvibrationenergyfromthecylindertotheNESinaone-wayirreversible

fashion.NumericalparametricstudiesidentifythreemainmechanismsforsuppressingVIV:

periodicresponse,quasi-periodicresponseandchaoticresponsesuppressionmechanisms.

WeinvestigatethesemechanismsbothnumericallybyWaveletTransform(WT)andPoincare

map method, analytically by a complexification- averaging technique. Each suppression

mechanism involves strong 1:1 resonance capture during which the NES absorbs and

dissipates a significant portion of energy fed from the fluid flow to the cylinder. Failure of

suppressionisassociatedwithrestoringtheunderlyingtriggeringmechanismofinstability,

whichisaseriesofsuperharmonicresonancecapturesfollowedbyescapesfromresonance.

Finally, using a numerical continuation technique, we perform a bifurcation analysis to

examine sensitive dependence on initial conditions and thus robustness of instability

suppression.



199

A0972-AcTIVELY-CONTROLLEDTurbulenceSIMULATIONSANDTHEIREffectson

THEAEROELASTICPROPERTIESOFTYPICALBRIDGEDeckSECTIONs

YuchaoLva,JinxinCaob,YaojunGec

aMasterstudent,TongjiUniversity,e-mail:[email protected]

bAssistantprofessor,TongjiUniversity,e-mail:[email protected]

cProfessor,TongjiUniversity,e-mail:[email protected]

Asoneofthemostadvancedexperimentaltoolstoreproducethenaturalturbulence,anewly-

built actively-controlled multi-fan wind tunnel facility was employed to investigate the

turbulenceeffectsonflutterderivativesandcriticalwindvelocityoftypicalbridgedecksin

this paper, through the sectional model test approach and the free-vibration identification

methodforflutterderivatives.Thesimulationofturbulentflowfieldsincludingnarrow-band

andwide-bandoneswithdiverseturbulenceintensitiesandintegrallengthscalesisachieved,

whichisdifficultforgrid-generatedturbulenceinconventionalboundarylayerwindtunnels.

Threerepresentativesections,includingathinflatplate,astreamlinedsingle-boxgirder,and

astreamlinedtwin-boxgirderwithacentralslotwereconsideredinthisstudy.Theresults

tend to indicate that turbulence has significant effects on each deck section, meanwhile

turbulence intensity and integral length scale each has respective influence on flutter

oscillationsofbridgedecks.Thegeneralconclusionseemstobethatthemorestreamlineda

sectionis,themoresensitivetoturbulenceitsflutterderivativesare.Atthesametime,flutter

critical wind velocities have been recorded. It is found that the critical wind speeds under

small turbulence intensities are larger than those under the smooth flow, yet under large

turbulence intensities theresults turn to theopposite. With the increase in integral length

scales,thefluttercriticalwindspeedsforallthreesectionswillgraduallydecreaseorincrease

until they equals the critical wind speed values under the smooth flow. Similar to flutter

derivatives,fluttercriticalwindspeedsofstreamlinedsectionsseemtobemoresensitiveto

theturbulence.Inaddition,fluttercriticalwindspeedsbasedonthetwodegree-of-freedom

coupledflutterequationwerecalculatedusingtheflutterderivativedataidentifiedinthetests.

Thecalculatedresultsarewellagreedwiththemeasuredones,whichverifiesboththeflutter

derivativesandcriticalwindspeedsfromtheexperiment.



200

MS17: Stability and Failure of Structures and Materials

A0149- FREQUENCY ANALYSIS FOR VIBRATING BENDING BEAMS VIA A NEW

STATICAPPROACH

ZhenyuChena,C.W.Limb

aPh.D.student,CityUniversityofHongKong,e-mail:[email protected]

bProfessor,CityUniversityofHongKong,e-mail:[email protected]

The natural frequencies of different vibration modes are useful for the understanding of

mechanicalpropertiesofengineeringstructural systems. Thisstudypresentsanewstatic

approach for solving some free vibration structural systems to determine the natural

frequenciesofbeammodelsunderdifferentboundaryconditions.Tothisend,itisobvious

thatanystaticstructuralsystemscanbeconsideredasspecialcasesofmoregeneraldynamic

structural systems. For vanishing time-depended variables, the governing equations of

motion can be reduced to static problems. Starting with the basic governing equation for

beamssubjecttoaharmonicloadandrestingonelasticfoundation,thegoverningequation

forbendingissolvedandapplieddirectlytoyieldthefreevibrationsolutions.Specifically,the

key idea is to assume a positive or negative generalized elastic parameter using the static

approachtocorrespondto therealand imaginary frequencyparametersvia freevibration

analysis,respectively.Consequently,anappropriatenegativeelasticfoundationparameteris

determined and the natural frequencies can be obtained. Its basic assumption is in the

presenceofaconcentratedload,thedeflectionofabeambecomesinfinitewhenthestiffness

approacheszero.Acomparisonwithrespecttoclassicalfreevibrationsolutionsispresented

andexcellentagreementisillustrated.Furthermore,fastnumericalconvergenceofthenew

approachhasalsobeendemonstrated.Thisstaticapproachforfreevibrationproblemscan

beextendedtothedynamicsofmorecomplicatedstructuralsystems.



201

A0247-HAZARD-INDEPENDENTSTUDYOFTHESTABILITYSENSITIVITYOFTHE

LOWRISEFRAMESYSTEMSSUBJECTEDTOTHEEXTREMELOADINGCONDITIONS

P.Dahala,C.Mullenb

aPh.D.Student,UniversityofMississippi,e-mail:[email protected]

bAssociateProfessor,UniversityofMississippi,e-mail:[email protected]

From the scenarios of different hazardous events (Hurricane, Flood, Earthquake, Tsunami,

Blast,Impactetc.),aneedtoaccountforthepossibledamageisgettingutmostimportance

whileinvestigatingthestabilityofbuildingstructures.Thispaperaimstoprovideaframework

to establish a comparison of stability sensitivity of the frame systems (Steel and RC) in

different levels when subjected to the extreme loading conditions. As an effort to avoid

cumbersomecalculationsassociatedwithparticulardamageevents, theworksattempts to

provide a hazard – independent approach for the application of damaged conditions.

Regardless of the event that characterizes specific damage states, significant damage to

structuralmemberstypicallyreducestherespectivestiffnessoftheelement.Thisprincipleis

utilizedinthehazard–independentdamageapproachbysimplyreducingsectionmoduliof

thetargetedstructuralmemberwithrespecttolateralloaddirectioni.e.,thestiffnessalong

the direction of lateral loading is investigated. This procedure results in a weakened, or

softened,structuralsystemthatisusedtoapproximatetheimpactonstiffnessingloballevel,

andthusthestabilityofoverallsystem.TheworkdoneforthestabilitysensitivityofLowrise

steelmomentframeswaspresentedinEMIConference2017heldinSanDiego.Itisextended

furthertoRCmomentresistingframesandcomparisonofsomeresultsweredemonstratedin

EMI Conference 2018 at MIT. The work accounts for the geometric non-linearities of the

structuralmembersandthesystemasawhole.Proceedingfurthertomakeittomorerealistic

scenario,theresultsfrom3DassemblyofbothRCandSteelFrameswillbediscussed.AISC

approachtosofteningofsectionmoduliformemberstoaccountforplasticresidualstresses

andthateffectoflocalizedplasticityatthesectionandmemberlevelwillbeinvestigated.



202

A0332- ACharacterization of nonlinear constitutive behavior of ceramic-based

compositeusingdigitalimagecorrelation

JIXiaohuiaHAOZiqingaLiuLiua*,

aSchoolofAerospaceEngineering,BeijingInstituteofTechnology,Beijing100081,PRChina

The tensile and compressive behavior of the ceramic matrix composite (CMC), were

investigated in varying orientations relative to the 0/90 woven carbon fibers. The ratio of

sheartonormalstresswasabout1-3.73,dependingonthefiberorientation.Thenon-linear

stress–strainbehaviorundercombinedtensileandshearstressandthelinearelasticbehavior

under compression load were determined through full-filed deformation measurement

technique. The coupling between normal and shear stress of the 2D-woven CMC under

proportionalloadingconditionswereidentified.Theoff-axistensiontestresultsshowthatthe

evolutionrateofdamageisacceleratedunderthecorrespondingcombinedbiaxialtensionand

shear loads.Anovelgeneralizednonlinearstress-strainconstitutiverelationship isderived

using the complementary strain energy density function and the material properties have

beendeterminedthroughtheappliedstressandDICmeasuredstrain inmaterialprincipal

coordinate using the least square regression. The nonlinear coupling between tensile and

shearstresshasbeenconsideredintheproposedmodel.Itisdemonstratedthatthepredicted

stress-strainbehaviorunderoff-axisloadingagreeswiththeexperimentalmeasuredbehavior

verywell.



203

A0380- PLY-GAP EFFECTS ON BUCKLING BEHAVIOR OF COMPOSITE CONIC

BARRELBYAUTOMATEDFIBERPLACEMENT

TianliangQINa,MufengDUANb,JifengXUc

aSeniorEngineer,BeijingKeyLaboratoryofCommercialAircraftStructuresandComposite

Materials,BASTRI,COMAC,e-mail:[email protected]

bEngineer,BeijingKeyLaboratoryofCommercialAircraftStructuresandComposite

Materials,BASTRI,COMAC,e-mail:[email protected]

cDeputyChiefEngineer,BeijingKeyLaboratoryofCommercialAircraftStructuresand

CompositeMaterials,BASTRI,COMAC,e-mail:[email protected]

Automated fiber placement (AFP) is increasingly used in the manufacturing of aircraft

compositestructures,since it isaprocesscapableofqualityensuranceandcostreduction.

However, duo to the geometric effects, ply-gaps inevitably occur in the process of

manufacturingcompositeconicbarrelwithfiberreinforcedplies.Asply-gapswouldreduce

themechanicalpropertiesofthestructures,suchasstiffnessandstability,itisnecessaryto

establishananalysismethodtoinvestigatetheply-gapeffectsforcompositeconicbarrel.A

methodcombiningtheanalyticalsolutionwiththefiniteelementanalysisisproposedinthis

paper. First, the equivalent mechanical properties of the ply with gaps were calculated

analytically.Then,fieldvariableswereusedinthefiniteelementmethodtorelatethevariable

gaps with the ply equivalent properties in the barrel. The finite element models of AFP

composite conic barrel under tensile, compressive and shearing loads were established to

perform the linear buckling analysis. The buckling loads and their corresponding buckling

modesforthecompositeconicbarrelswithandwithoutply-gaps,respectively,werecompared

tostudytheply-gapeffectsonthestiffnessandstability.Further,ply-gapdistributionsinAFP

composite conic barrel were rearranged, theoretically, to evaluate how the stability can be

improved.Theanalysisresultsindicatedthattheply-gapscanobviouslyreducethebuckling

loadsandchangethebucklingmodesofcompositeconicbarrelundertensile,compressive

andshearingloads.Adequateply-gapwidthcontrolanddistributionareeffectivefactorsto

improvethestabilityofcompositeconicbarrelmanufacturedbyAFPprocess.



204

A0384- Seismic Performance of Unreinforced Masonry Walls with Boundary RC

Frame

You,Young-Chana,Kim,Min-Sunb,Lee,Hyun-Jeeb

aSeniorresearchfellow,KoreaInstituteofCivilEngineeringandBuildingTechnology,e-mail:

[email protected],

bResearcher,KoreaInstituteofCivilEngineeringandBuildingTechnology,e-mail:

[email protected],[email protected]

Koreangovernmenthasbeenintensifyingthebuildingseismicregulationsforreducingthe

possible seismic damage of the buildings, and it is especially accelerated after Gyeongju

Earthquakein2016.Oneofthemistowidenthescopeofbuildingsthatreviewseismicdesign

conformity when a building permit is granted. But the mandatory seismic design for the

buildingswasstillrestrictedtothreestoriesorhigher,1,000m2ormoreuntil2016.Andat

thesametime,itwasannouncedthatitwouldbeexpandedtomorethan2storiesor200m2

byDecember2017.Ontheotherhands,mostofthedetachedhousesorlow-riseresidential

buildings have been constructed using unreinforced masonry wall in Korea. These

conventionalunreinforcedmasonrywallstructureswerereportedtobevulnerabletoseismic

activity, causing lots of casualty and property losses from the previous earthquake. The

reinforced masonry wall structures are considered to be a good engineering solution

mechanically, but it will take many years to prepare and distribute all of the industry's

infrastructure including structural design, fabrication, and construction to the market. The

purposeofthisstudyistoinvestigatetheseismicperformanceofunreinforcedmasonrywalls

whichisreinforcedwithboundaryRCframetocheckthepossibilityofreplacingreinforced

masonrywallstructures.BoundaryRCframecomposesofonetie-beamandtwotie-columns

in this study. Two specimens are prepared, with the same overall dimension and material

properties. 1st test specimen represented a typical unreinforced masonry wall and 2nd test

specimenwasreinforcedwithboundaryRCframeonthe1sttestspecimenadditionally.Cyclic

loading test was carried out to compare the seismic performance of two different test

specimens.Fromthetestresults,itwasfoundthatfailuremodeofunreinforcedmasonrywall

changed from ‘fragile’ to ‘ductile’ fundamentally by the installing of boundary RC frame.

Additionally, the increased maximum loads of the test specimen with boundary RC frame

correspondingtothesameloadingschedulesresultsingreatincreasingofenergydissipation

capacityabout2~4times.Finally,itwasconcludedthatinstallationofboundaryRCframeon

unreinforced masonry wall can be a good alternative measure for the replacement of

reinforcedmasonrywallsstructureinKorea.



205

A0473- characterization for COMPRESSION-SHEAR COMBINED PROPERTIES of a

compositematerial

TirenHea,LiuLiub*,JifengXua

aBeijingKeyLaboratoryofCommercialAircraftStructuresandCompositeMaterials,BASTRI,

COMAC

bSchoolofAerospaceEngineering,BeijingInstituteofTechnology,Beijing,China

Ascompositematerialshavebeen increasinglyused forprimarystructuresoncommercial

airplane,theabilitytomeasuretheircomplexmechanicalpropertiesefficientlyandtoanalyze

their failuremechanismwithhighfidelitybecomesevenmoreimportant. Inthisstudy, the

nonlinearconstitutivelawforIM7/8552fiber-reinforcedunidirectionalcompositematerial

undermulti-axialloadshasbeenidentified,andfurthermorethefailurecriterionandmodes

have been discussed accordingly. First, improved short beam shear (SBS) tests were

performed,andthedatarecordedbydigitalimagecorrelation(DIC)techniquewasusedto

characterizethecoupledcompression-shearstress-strainrelationship.Thenacompensation

scheme by finite element model updating (FEMU) method was employed to approach the

materialconstitutiveparametersthroughtheprocessofcorrectingtheparametersiteratively

untiltheagreementofsimulatedFEMresultswiththemeasuredDICstrainfield.Atlast,the

uncertainties in DIC data reconstruction and the covariance matrix of the extracted

constitutive parameters are discussed too. To demonstrate its advantage, the proposed

nonlinearconstitutivelawwasusedtoanalyzedeformationmechanismandtosimulatethe

failuremodes.



206

A0586-BUCKLINGOFBEAMSSUBJECTTOINFLUENCEOFSURFACESTRESSES

FengLinaandY.Xiangb

aResearchAssistant,SchoolofComputing,EngineeringandMathematics,WesternSydney

University,LockedBag1797,Penrith,NSW2751,Australia

bProfessor,SchoolofComputing,EngineeringandMathematics,WesternSydneyUniversity,

LockedBag1797,Penrith,NSW2751,Australia

The micro-electromechanical systems (MEMS) or nano-electromechanical systems (NEMS)

areminiaturizedstructureswithmicroornanolengthscaledfeatures.Insuchstructures,the

existenceofsurfacestresseshasbeenreportedwhichmaygreatlyinfluencethemechanical

behavioursofsuchstructuresandshouldnotcannotbeignored.Thesurfacestressesmaybe

eitherinducedbymismatchingofthematerialpropertiesbetweenthesurfacelayerandthe

underlyingbulkmaterialsorbytheforeignadsorbateonthesurfacelayers.Inthisstudy,the

bucklingbehavioursofthebeamsincludingsurfacestresseffectsareinvestigated.Thebulk

core materials of the beams are assumed to be isotropic and the top and bottom layers of

beams are covered with atomic thin surface layers and are subject to compression. The

Reddy’sthirdordersheardeformablebeamtheoryisemployedtoderivedthetotalpotential

energy functional of the beam. The Ritz method is then applied to derive the eigenvalue

equationwhichcanbesolvedtoobtainthebucklingloadofthebeam.Thebucklingbehaviours

ofthelaminatedbeams,whichincludesurfacestresses,arepresentedanddiscussedindetails.



207

A0590- THERMAL POSTBUCKLING BEHAVIOURS OF FUNCTIONALLY GRADED

NANOCOMPOSITEPLATES

Y.Fana,H.-S.Shenb,Y.Xiangc

aVisitingResearchFellow,SchoolofComputing,EngineeringandMathematics,Western

SydneyUniversity,e-mail:[email protected]

bProfessor,SchoolofOceanandCivilEngineering,ShanghaiJiaoTongUniversity,e-mail:

[email protected]

cProfessor,SchoolofComputing,EngineeringandMathematics,WesternSydneyUniversity,


Thecurrentinvestigationdealswiththethermalpostbucklingbehavioursofnanocomposite

platesconsistingofcarbonnanotubereinforcementsorgraphenesheetreinforcementsunder

a uniform temperature field. The material properties of carbon nanotube reinforced

composite (CNTRC) and graphene reinforced composite (GRC) are both assumed to be

temperature-dependent.TwotypesoffunctionallygradedpatternsfortheCNTRCsingleplate

and the GRC laminated plate are proposed. The plates are assumed to rest on a Pasternak

foundationwithalledgessimplysupportedandin-planeimmovable.TheReddy’sthirdorder

sheardeformableplatetheoryisemployedtoderivethepostbucklingequationswhichalso

include the effects of the von Karman geometric nonlinearity. A two-step perturbation

techniqueisusedtosolvethepostbucklingequationsandaniterationmethodisappliedin

the computation. The influences of the functionally graded patterns and the foundation

stiffness on the thermal postbuckling behaviours of the nanocomposite plates will be

presentedanddiscussedindetails.



208

A0681- Imperfections by Design: Interactive Buckling and Postbuckling in

ArchitectedMaterials

YinghaoZhaoa,b,AmalJeraldJosephMariaJosephc,ChunpingMab,Megan

Skibinskib,BurakGulb,MaryGraceSylvesterc,andNanHub

aDepartmentofCivilEngineering,SouthChinaUniversityofTechnology,China

bDepartmentofCivil,EnvironmentalandGeodeticEngineering,TheOhioStateUniversity,

USA,e-mail:[email protected]

cDepartmentofMechanicalandAerospaceEngineering,TheOhioStateUniversity,USA,

Harnessing elastic instabilities in materials have recently enabled new classes of tunable

systemsanddevices,suchassoftfluidicactuator,metamaterial-basedartificialmuscle,gating

mechanism,origami-inspiredartificialmuscles,nonlinearforcesensor,biomimeticactuators

atarchitecturalscale,andsoftrobotics,etc.Thecommonfeatureofthoseinstability-induced

smartsystemsistheamplifyingforceandaugmentedmotioncomparedtotheirtraditional

stiffcounterparts.Achievingtheseamplifyingeffectsusuallyreliesonharnessingtailorable

architectedmaterials(alsoknownasmechanicalmetamaterials)asthebuildingblock.Oneof

theongoingchallengesishowdefectschangethepropertiesofmechanicalmetamaterialsto

achieve targeted functionalities with aperiodic materials. In response to such need, we

introduce a class of shell structures which undergoes interactive buckling induced by

strategically controlling the number and distribution of geometric defects. By combining

finite-element simulations and desktop-scale experiments, we found that the interactive

bucklingcanbeinducedbystrategicallycontrolledthenumberandthedistributionofdefects,

leadingtoadeterministicactuationresponsecomparedtotheonewithoutgeometricdefects.

Ourstudytherebyopensavenuesforthedesignofthenextgenerationofactuatorsandrobots

withhighfidelityandlowsensitivityoverawiderangeoflengthscales.



209

A0705-SoilArchingEffectBasedStudyontheStressDistributionandFailureMode

oftheHolesforUnder-excavationinBuildingRectifying

QingxiaYuea,XinZhangb

aSchoolofCivilEngineering,ShandongJianzhuUniversity,Email:[email protected]

bSchoolofCivilEngineering,ShandongJianzhuUniversity,Email:[email protected]

Inthedesignofbuildingrectifyingwithunder-excavationmethod,thedeformationandthe

failuremodeoftheexcavationholesarethekeyproblems.Theywillaffectthedetermination

ofthekeydesignparameterssuchasexcavationdiameterandthedistancesoftheexcavation

holes.Inthisregard,someexperimentswerecarriedouttostudythestressredistribution,

failure mode of the excavation holes. First, a simulation model box was designed with the

ability to simulate the soil excavation. Then the soil excavation was done with the hole

diameter200mm,andthreecaseswithholedistancesof400mm,600mm,and800mmwere

adopted.Thesoilsettlementduetotheexcavationholewasmeasured.Itisfoundthatthere

arethreefailuremodeoftheexcavationholes:verticalirregularoval,horizontalirregularoval,

irregularcircle.Further,itisfoundthatthepressureofthesoilwilltransferfromtheupperof

thehole to thesidesoilbetweentheholes,whichmeanthat thesoilarchingeffectoccurs.

However,duetotheclusterholeseffect,therelativedisplacementissmall.Inthiscontext,the

fullarchingeffectcannotbeformed.Thus,anewcalculationformulaisputforwardwithsome

modifications to the fully arching effect. The calculation results are compared with the

experimental results, which agree well. Furthermore, it is found that as the hole distance

becomes bigger, the soil between the holes will form a steady arching foot, which is

unfavorabletothebuildingrectifying.Thus,itcanbeconcludedthatacriticalholedistance

existbetweensteadyarchingandunsteadyarching.Itcanbeconcludedfromthisexperiment,

2-3timesoftheholediameterisaproperholedistancefortherectifyingdesign.



210

A0776- CLASSIFICATION OF STEEL H-SHAPED CROSS-SECTIONS UNDER

COMBINED COMPRESSION AND BENDING CONSIDERING PLATE INTERACTION

EFFECT

HouXuesonga,ChengXinb

aMiss,CollegeofArchitectureandCivilEngineering,TaiyuanUniversityofTechnology,e-


bAssociateProfessor,CollegeofArchitectureandCivilEngineering,TaiyuanUniversityof


Thecross-sectionclassificationconceptisanimportantpartofsteelstructuraldesign.Inorder

to distinguish the plastic deformation ability of cross-sections, the cross-sections of

compression-bendingmemberscanbedividedintofourclassesaccordingtodifferentplate

width-to-thicknessratiolimits.Howeverbycomparingthewidth-to-thicknessratiolimitsof

thecurrentspecificationsincludingGB50017,Eurocode3,AISC360,AIJ,itispointedoutthat

most of the specifications do not consider the interaction effects of steel plates of cross-

sections.Inthispaper,steelH-sectionswerechosenasthemainresearchobjects.Toconsider

theplateinteractioneffectincross-sectionclassifications,parametricstudyofsteelH-sections

with different width-to-thickness ratios and axial force ratios was carried out by software

ABAQUS. The finite element model was verified by the experimental results in the related

literatures.Throughthesimulationresult itwasobservedthatdifferentwidth-to-thickness

ratiosandaxialforceratioscouldleadtodifferentfailuremodes,bearingcapacityandductility,

sotheinteractioneffectofadjacentplatewasconfirmed.ThenthevaluesofMu/Mecofallthe

finiteelementmodelswereobtained,whereMuistheultimatebendingcapacityandMecisthe

elasticbendingmoment,withinwhichthedominatingparametersoffiniteelementmodels

with Mu/Mec=1 were extracted. Based on these cross-sections with Mu/Mec=1, the fitted

functionfortheclassificationlimitofclass3andclass4cross-sectionsintermsofflangeand

webwidth-to-thicknessratiosandtheaxialforceratioswasproposed.Finally,theproposed

limitationswerecomparedwiththespecificationsincludingGB50017,Eurocode3,AISC360

and AIJ to further prove its correctness, where it is observed that each specification is

relativelyconservativecomparedwith theresultsof thenewlyproposed limitation.This is

mainlybecauseallthespecificationsexceptAIJfollowtheruleofsingleplateconcept,i.e.the

interactioneffectbetweenflangeandwebisignored.Moreover,consideringtheinteraction

effectofadjacentplate ismore in linewiththeactualmechanicalpropertiesofplates,and

wouldleadtocertaineconomicbenefits.



211

A0839- FAILURE AND BUCKLING ANALYSES OF COMPOSITE LAMINATES WITH

CUT-OUTS:THEORYANDEXPERIMENTS

JianxiangWanga,ShuLia,HaiDonga,JianlinChena,YanWangb,JifengXub,

ZhengLia

aDepartmentofMechanicsandEngineeringScience,CollegeofEngineering,Peking

University,Beijing100871,China,e-mail:[email protected]

bBeijingAeronauticalScienceandTechnologyResearchInstitute,Beijing100083,China.

Fibre-reinforcedcompositelaminateswithcut-outsmayexhibitcomplexfailuremechanisms

andmodes.Oneofthefailurecriteriaisbasedonacharacteristiclengthattheedgeofthecut-

out.However,thedeterminationofthecharacteristiclengthisalong-standingdifficultissue,

and how it is related to the properties and geometric parameters of the laminate remains

elusive.Moreover,wealsoshowbyexperimentsthatlaminateswithbigcut-outsmayexhibit

localbucklingunderin-planetension.Therefore,first,weshalldiscussthedeterminationof

thecharacteristiclength,andpresentourresultfromaviewpointofnon-localelasticitytheory

of composites. By combining the predicted characteristic length with the improved Puck’s

failuretheory,wedemonstratethatthepredictedstrengthoflaminateswithcircularcut-outs

qualitativelyagreewiththeexperimentalmeasurements.Nevertheless,wealsopointoutthat

therelationbetweenthecharacteristiclengthandthesizeofthecut-outsstilldeservesfurther

investigation.Then,weshowourexperimentalobservationsofthefailuremodesandbuckling

phenomenaoflaminateswithbigcut-outsundertension.Thefailuremodesincludefracture,

splitting, and local buckling. Some laminates may buckle before damage, and the critical

buckling load can be calculated by a power law of the size of the cut-outs. Therefore, the

predictionsofthebehavioroflaminateswithcut-outsshouldbedevelopedtakingintoaccount

differentdeformationandfailuremodes.



212

A0875-BucklingofCompositePlateswithReinforcedOvalHoles

LingweiTanga,YanWangb,MufengDuanc,JifengXud

aEngineer,BeijingKeyLaboratoryofCommercialAircraftStructuresandComposite

Materials,e-mail:[email protected]

bEngineer,BeijingKeyLaboratoryofCommercialAircraftStructuresandComposite

MaterialsPosition,affiliation,e-mail:[email protected]

cEngineer,BeijingKeyLaboratoryofCommercialAircraftStructuresandComposite

Materials,e-mail:[email protected]

dDeputyChiefEngineer,BeijingKeyLaboratoryofCommercialAircraftStructuresand

CompositeMaterials,e-mail:[email protected]

As larger passenger windows are being implemented to increase the comfortableness in

aircraft cabin, stability of composite fuselage panel with cutout becomes a more severe

problem.Reinforcementsadjacenttowindowcutoutmustbeextensivelyevaluatedtokeep

structuralstabilityunderserviceloadsandtooptimizestructuralweightandmanufacturing

costs.Thispaperpresentsexperimentalandnumericalresultsoflaminatedcompositesquare

plates with reinforced oval-like holes. Composite plates with and without window frames

weretestedtoinvestigatetheeffectsofwindowframeonbucklingresponsesubjectedtoshear

loadings.InsteadofconventionalTshapedwindowframe,flatwindowframeswerefabricated

fromdiscontinuousfibercomposite(DFC)usingcompressionmoldingbeforeattachingtothe

laminatecompositeplatebyfasteners.Eliminatingtheperpendicularribbenefitsstructural

weight saving and eases the manufacturing process. In experimental tests structural

deformationanddamageweremonitoredbybothstraingaugesanddigitalimagecorrelation

(DIC)equipment.Numericalanalysiswasconductedusingfiniteelementmethodtosimulate

thebucklingbehaviorof thecompositeplateswithcutouts.Theresults fromexperimental

testsandnumericalanalysiswerecorrelatedwell,andshowthatwindowframesefficiently

preventthecompressiveregionfromlocalbuckling.



213

A0925- Strengthening, Failure and Twinning Mechanisms of Graphene/Copper

Composites

NingHua,ShayuanWengbandHuimingNingc

aProfessor,CollegeofAerospaceEngineering,ChongqingUniversity,e-mail:

[email protected]

bDoctoralCandidate,CollegeofAerospaceEngineering,ChongqingUniversity,e-mail:

[email protected]

bAssociateProfessor,CollegeofAerospaceEngineering,ChongqingUniversity,e-mail:

[email protected]

Grainrefinementandintroducingreinforcementshavebeentwocommonandeffectiveways

to improve the strength of metals, where interfaces are found to play a critical role in

mediating the overall mechanical properties of metals based composites. In this study, the

effectsofinterfacesinCu//NiandCu//graphenenanolaminatesonmechanicalpropertiesare

investigatedwithMDsimulations.Itisfoundthatcoherenttwininterfaceshowssignificant

strengtheningeffectsviaplasticdeformationduetothedislocationsinkingeffects.Graphene

reinforcements are then incorporated into Cu matrix, and the underlying strengthening

mechanismofgrapheneandtheeffectoflamellathicknessandfailuremodeareinvestigated.

Incorporatinggraphenemonolayerisprovedtosimultaneouslycontributetothestrengthand

ductilityofthecomposites.Grapheneaffectedzoneisdevelopedandintegratedwithruleof

mixtures and confined layer slip model to describe the elastic properties of NGCu and the

strengtheningeffectoftheincorporatedgraphene.Theanisotropicmechanicalresponsesand

deformation behaviors of graphene/copper nanolaminates under compression are further

explored,dislocationslideandtwiningarefoundtobethedominantdeformationmechanisms

under compression along different crystallographic orientations. A graphene wrinkle

facilitated twinning mechanism are observed and analyzed, which may contribute to the

manufactureofhigh-strengthmetalcompositecombiningthetwinstrengtheningandcarbon

materialstrengtheningeffect.



214

MS18: Computational Modeling of Advanced Materials

and Novel Structural Systems for Hazard Mitigation

A0321- Enhancing Seismic performance of porcelain electrical equipment using

baseisolation

BAIWena,DAIjunwua,YANGYongqianga

aKeyLaboratoryofEarthquakeEngineeringandEngineeringVibration,Instituteof

EngineeringMechanics,ChinaEarthquakeAdministration,Harbin,Heilongjiang,150080,

China

Aseconomydevelops, thesocietyrelies increasingmoreonelectricity.Ensuringthesteady

supply of electricity during natural hazards like earthquakes is of importance. However,

porcelaincylindricalelectricalequipment(PCEE),askeycomponentofpowersupplysystem,

performs badly during earthquakes, which might significantly increase the probability of

poweroutage.InordertoenhancetheseismicperformanceofPCEE,baseisolationisapplied.

Three typical PCEEs with different frequencies, are taken as example and their dynamic

responsesunderearthquakesarestudied.Effectivenessofbaseisolationatdifferentperiods

arecompared.Analysesareconductedusingfiniteelementmethod.Resultsshowthatbase

isolationiseffectivenessatenhancingPCEEseismicperformance.Baseisolationcanreduce

PCEE acceleration and relative displacement responses. The effectiveness of base isolation

increasesasequipmentfrequenciesincrease.Theeffectivenessofbaseisolationincreasesas

base isolation period increases. Meanwhile, it should be noticed that the absolute

displacementresponsesofPCEEmayincreaseasBIperiodincreases.



215

A0360-CharacterizationandModelingofAdaptiveRubberBearing

YiEnJia,C.S.Tsaib,YingZhoucandXilinLud

aMasterStudent,ResearchInstituteofStructuralEngineering&DisasterReduction,College

ofCivilEngineering,TongjiUniversity,Shanghai,e-mail:[email protected]

bDistinguishedProfessor,DepartmentofCivilEngineering,FengChiaUniversity,Taichung,


cProfessor,ResearchInstituteofStructuralEngineering&DisasterReduction,Collegeof

CivilEngineering,TongjiUniversity,Shanghai,email:[email protected]

dChenungKongScholarsProfessor,ResearchInstituteofStructuralEngineering&Disaster

Reduction,CollegeofCivilEngineering,TongjiUniversity,Shanghai,email:

[email protected]

Inordertosystematicallyinvestigatethemechanicalbehaviorofanadaptiverubberbearing

(ARB), mathematical formulations for nonlinear analyses have been derived from the

proposed concept of the ARB. Based on the concept of the force equilibrium via the

combination of rubber and the sliding core layer by layer, the mathematical formulations

presentingtheadaptivecharacteristicsoftheentireARBsystemcanbeobtainedbywayofthe

seriesofconnectionsofalllayersintheentiredevice.Byvirtueofthederivedmathematical

formulations,thephenomenaoftheARBisolatorpossessingadaptivefeaturescanbeclearly

understoodeventhoughitisacompletelypassivedevice.Numericalanalysiswhichisingood

agreementwithexperimentalresultsinferthattheeffectivestiffnessanddampingratioofthe

ARB isolator change continually during an earthquake and are controllable through

appropriatedesign.



216

A0363- Multi-Physics Simulation on Passive Patch Antenna Sensor for Wireless

StrainMeasurement

DanLia,YangWanga,b

aSchoolofCivilandEnvironmentalEngineering,GeorgiaInstituteofTechnology

bSchoolofElectricalandComputerEngineering,GeorgiaInstituteofTechnology

Apassivepatchantennasensor isanoveldevice forwirelesslymeasuringstrainonabase

structure.Theelectromagneticresonancefrequencyofthepatchantennaishighlyrelatedto

itsdimension.Whentheantennasensorisdeformedalongwithabasestructureunderstrain,

theresonancefrequencychangecanbeidentifiedwirelesslyandusedtoestimatethestrain.

This research investigates mechanical and electromagnetic behaviors of the patch antenna

sensorbymulti-physicssimulation.A3Dfiniteelementmodelisbuiltforbothmechanicaland

electromagneticsimulation.Inthemechanicalsimulation,nonlinearconstitutiverelationship

ofmaterialisconsideredforcalculatingaccuratedeformationunderloading.Dimensionsof

thedeformedantennamodelarethenusedfortheelectromagneticsimulation,whichadopts

partially air-filled cavity modelling technique for efficiently calculating the resonance

frequency of the patch antenna sensor. The accuracy of this mechanics-electromagnetics

coupledsimulationisvalidatedthroughlaboratoryexperiments.



217

A0368- SECTION AND FINITE ELEMENT ANALYSIS OF SEISMIC UHPC BRIDGE

PIERSWITHHIGHSTRENGTHSTEEL

MohamedA.Moustafaa,NegarNaeimib,MahmoudAboukifab,SureshDhakalb

aAssistantProfessor,DepartmentofcivilandEnvironmentalEngineering,Universityof

Nevada,Reno,email:[email protected]

b Graduate Student Researcher, Department of civil and Environmental Engineering,

UniversityofNevada,Reno

AdvancedbehaviorofUltraHighPerformanceConcrete(UHPC)hasledtoagrowinginterest

amongtheconstructionindustryworldwide.Currently,UHPCisusedwidelyinbridgedeck

joints and connections, and to a less extend in structural components or larger structural

applications.ThestructuralandseismicbehaviorofUHPCforlargercomponentsisnotfully

understood.Moreover,usinghighstrengthsteel(HSS)withUHPCstructuralcomponentscan

openthedoorsfornewdesignopportunities,butyetneedtobestudiedproperlyfordesign

optimizationandobtainedductilityforseismicdesign.Theobjectiveofthispresentationisto

provide better understanding of the seismic behavior and failure mechanism of UHPC

componentswithconventionalandHSSreinforcement(mainlybridgepierscolumnsandbent

caps) due to earthquakes. Two-dimensional sectional analysis using a recently developed

software, MC-BAM, and detailed three-dimensional (3D) finite element modeling (FEM) is

utilized.Forthe3DFEM,thevalidityofTotalStrainCrackmodels,asareadilyimplemented

modelinDIANAFEAsoftware,incapturingUHPCbridgepiersfailuremechanismandplastic

hinge behavior is investigated. The UHPC behavior in tension and compression is

independentlydefinedusinguniaxialstress-strainrelationships,whicharedeterminedusing

extensiveUHPCmaterial tests.TheoverallresponseofUHPCbridgepiersundercombined

axial (gravity) and pushover lateral loads is numerically studied. A reference conventional

reinforced concrete bridge pier column is also presented to study the relative increase in

seismicdisplacementandforcecapacitiesofUHPCbridgepiers.Differentreinforcementratios

alongwithvaryingreinforcementgradesareusedtostudytheeffectoflargerreinforcement

ontheoverallseismicbehaviorofUHPCstructuralcomponents,whichcaneventuallyleadto

newdesignstrategies.



218

A0671-SystemLevelAnalytical,ExperimentalandHybridSimulationofResilient

HighwayBridges

YingjieWua,SelimGünayb,KhalidM.Mosalamc

aGraduateStudent,UniversityofCalifornia,Berkeley,e-mail:[email protected]

bProjectScientist,UniversityofCalifornia,Berkeley,e-mail:[email protected]

cTaiseiProfessorofCivilEngineering,UniversityofCalifornia,Berkeley,e-mail:

[email protected]

Thispaperpresents themain featuresandanalytical,experimentalandhybridsimulations

conductedtocharacterizetheseismicperformanceoftwostructuralsubsystemsdesignedand

constructedaroundtheconceptsofResilientStructuresandAcceleratedBridgeConstruction.

Thefirstsystemfocusesonachievingresiliencybyutilizingaclassofinnovativeconnecting

devices,termed“V-connector”.Itcanbeusedtoconnecttwoconstructionpartsinastructural

system, e.g., the column and the bridge deck, or the column and its foundation. The V-

connectoradoptsaspecially-designedV-shapegeometrytoestablishaconnectionthatforms

an isolation layer,whileutilizing its intrinsic friction toachieveenergydissipation,bothof

which are required for seismic resiliency. The resiliency is achieved in terms of the elastic

behavior of the bridge components that would otherwise show inelastic behavior using

conventionaldesign,likethecolumns.Theconnectoritselfisalsosupposedtoremainelastic

during the earthquake. Accelerated Bridge Construction is obtained by assembling pre-

manufacturedstructuralpartsincludingtheV-connectoritselfonsite.Inthesecondsystem,

theconceptofresiliencyisincorporatedintheformofre-centeringbehaviorofthecolumns.

Re-centeringcolumnsaredesignedtoexperienceonlyminordamage locatedat thebeam-

column interface under the same seismic demands that would cause extensive damage in

conventional columns, and to return to their original position after the earthquake by

unbondedpost-tensionedelements.Thisresultsinasignificantreductionintherepaircosts

anddowntime.AcceleratedConstruction isachievedbyutilizingpre-castcolumnsandend

beamsthroughaninnovativesocketconnection.Theworkpresentedhereisanenhancement

andadifferentoutlooktoanearlierresearchconductedonsimilarsystems.



219

A0695-StudyontheImpactResistanceCapacityoftheHoneycombSandwichPanel

BasedontheMiuraOrigamiPattern

Ruijun.Maa,Jianguo.Caib,Jian.Fengc

aPhDCandidates,SchoolofCivilEngineering,SoutheastUniversity,Nanjing210096,China.

Email:[email protected]

bProfessor,KeyLaboratoryofC&PCStructuresofMinistryofEducation,NationalPrestress

EngineeringResearchCenter,SoutheastUniversity,Nanjing210096,China.Corresponding

AuthorEmail:[email protected]

cProfessor,NationalPrestressEngineeringResearchCenter,SoutheastUniversity,Nanjing

210096,China.Email:[email protected]

Honeycomb sandwich structures have excellent energy absorption capabilities, combined

with good mechanical properties and low density. These characteristics make them ideal

structuresysteminmanyengineerfields,suchlikecivilengineering,transportationindustry

andaerospaceindustry.Thiskindofstructureisconsistoftopandbottomfacesheetanda

honeycomb core between them. In this paper, a novel honeycomb sandwich panel was

proposed by introducing miura origami pattern as imperfection into regular hexagonal

honeycombcore.Athreedimensionalfiniteelementmodelwithmicro-structureconsidered

of thenovelpanelwasbuilt tovalidatetheenergyabsorptionpropertyunderdrop-weight

impactloadcase.Severalsimulationswithdifferentimpactenergywereconductedandthe

calculationresultsincludingabsorptionenergy,plasticareaandindentationdepthonthetop

face sheet were investigated. The numerical results showed that more than 80% impact

energywasabsorbedbythetopface-sheetandhoneycombcore.Thenovelpanelabsorbed

moreimpactenergyinhoneycombcorethanthetraditionalonedid.Andtheimpactingcaused

larger plastic area on the novel panel. At the second part, the kinematic and geometry

propertiesofmiurapatternwerediscussedtoillustrationtheenergyabsorptionprocessof

thehoneycombcore. Thepanelswithrigid foldablepattern andnon-rigid foldablepattern

werecompared.Inaddition,theeffectofthefoldangleandcorelayeronabsorbingimpact

energywasdiscussedtoproposeadesignmethodofnovelhoneycombpanelwhichwasused

tofindtheoptimalstructureforabsorbingimpactenergy.



220

A0729- PRIMARY STRUCTURAL CONFIGURATION INVESTIGATION OF A NOVEL

COUPLINGARMCONNECTINGTWOFLOATINGSTRUCTURES

TaoLia,XudongQianb,AzizMerchantc,AnisHussaind,AmitJaine,BernadA.P.

Francisf,AnkitChoudharyg

aResearchFellow,Keppel-NUSCorporateLaboratory,NationalUniversityofSingapore,e-


bAssociateProfessor,DepartmentofCivilandEnvironmentalEngineering,NationalUniver-

sityofSingapore,e-mail:[email protected]

cResearchEngineer,KeppelTechnology&Innovation,e-mail:

[email protected]

dResearchEngineer,KeppelMarineTechnologyDevelopment,e-mail:

[email protected]

eResearchEngineer,KeppelTechnology&Innovation,e-mail:[email protected]

fResearchEngineer,KeppelDeepwaterTechnologyDevelopment,e-mail:

[email protected]

gResearchEngineer,KeppelTechnology&Innovation,e-mail:

[email protected]

This study reports the primary study on the configuration of a novel coupling arm system

connectingtwofloatingstructuresunderextremewavecondition.Thecouplingarmconsists

of circular hollow section tubes, a pneumatic piston and rotational flexible joints. The

pneumatic piston is designed to absorb the relative surge motion between two floating

structurestopreventpotentialcollision,andtherotationalflexiblejointsareusedforresisting

thebendingloadsduetodifferentrelativemotions.Finiteelementanalysesarecarriedoutto

determinetheinitialnumberoftheflexiblejointsofthecouplingarm.Severalanalysiscases

of thearmconfiguration withdifferentnumbersof the flexible joints are investigated.The

analysiscasesarethencomparedintermsofthereactionforceofthecouplingarmandthe

rotationsoftheflexiblejoints.Finally,theoptimizedstructuralconfigurationforacoupling

armof25.35misrecommended.



221

GS1: Stochastic Mechanics and Structural Reliability

A0227-TowardsStochasticModelingofTsunamis

ZhihengWanga,IrinaKTezaurb,PatrickLynetta,RogerGhanema

aSonnyAstaniDepartmentofCivilandEnvironmentalEngineering,UniversityofSouthern

California,210KAPHall,LosAngeles,CA90089,USA,e-mail:[email protected]

bExtremeScaleDataScience&AnalyticsDepartment,SandiaNationalLaboratories,P.O.Box

969,MS9159,Livermore,CA,USA,e-mail:[email protected]

cSonnyAstaniDepartmentofCivilandEnvironmentalEngineering,UniversityofSouthern


dSonnyAstaniDepartmentofCivilandEnvironmentalEngineering,UniversityofSouthern


Thistalkdescribesaprototypeofanext-generationstochastictsunamimodel,currentlyunder

developmentwithintheparallelandscalableTrilinos-basedAlbanyfiniteelementcodebase.

This emerging model differs from its predecessors in that it is based entirely on the full

nonlinear 3D incompressible Navier-Stokes equations and is amenable to uncertainty

quantification (UQ). The model is expected to accurately represent the nonlinear effects

inherentinthephysicalprocessesunderlyingtsunamis(e.g.,near-shoreevolutionofwaves)

and, when mature, enable probabilistic tsunami hazard analyses. We discuss some

preliminary work towards quantifying the model’s aleatoric uncertainties arising due to

variationsinmodelforcingandgeometry(bathymetry,coastaltopographylanduse)usinga

newadaptivepolynomialchaosexpansion(PCE)algorithmdevelopedwithinUQTk,anon-

intrusivehigh-performancelibraryforUQ.



222

A0454- Multidimensional Stochastic Damage Model for Concrete Under Fatigue

Loading

YanpengWanga,JieLib

aPhDStudent,TongjiUniversity,[email protected]

bProfessor,TongjiUniversity,[email protected]

Stayingtheframeworkofclassicalelastoplasticdamagemechanics,anewkindofstochastic

damagemodelthatissuitableformultidimensionalfatigueloadingwasproposedbasedon

theone-dimensionaldamageevolutionlawestablishedbefore.Tobridgethegapbetweenone-

dimensionalandmulti-dimensionaldamageevolution,theconceptofenergyequivalentstrain

isemployed.Toexhibittheapplicationoftheproposedmodel,aseriesofnumericaltestswas

conducted on reinforced concrete beams without web reinforcement, considering the

randomness in constitutive relationship of concrete. Two kinds of failure modes were

identifiedintheresults,i.e.,tensilefatiguefailureofreinforcementandcompressivefatigue

failureofconcrete.Alsoitisdiscoveredthattherandomnessinconcreteispossibletoleadto

changeoffailuremodesofthereinforcedconcretebeamsunderfatigueloading.



223

A0554- A Generic Framework For Probabilistic Damage Characterisation Using

UltrasonicGuidedWaveinTheFrequencyDomain

Wang-JiYana*,DimitriosChronopoulosb,SergioCantero-Chinchillac

aInstituteforAerospaceTechnology&TheCompositesGroup,TheUniversityofNottingham,


bInstituteforAerospaceTechnology&TheCompositesGroup,TheUniversityofNottingham,


cInstituteforAerospaceTechnology&TheCompositesGroup,TheUniversityofNottingham,


Ultrasonicguidedwave(GW)whichcanbeactuatedbypiezoelectrictransducersinstalledon

structures has been proven to be sensitive to small and various types of damages. The

reflection/transmissioncoefficientscorrespondingtovariousdamageshasthepotentialtobe

damage-sensitive features in the field of structural health monitoring. This study aims at

formulating a generic framework for probabilistic damage characterization based on

reflection/transmissioncoefficients.Thepresentworkiscomposedoffivecoreelementsthat

makefulluseoftheBayesiansystemidentificationframeworktoaccountformeasurement

noiseandmodelingerrorsintandemwithwaveandfiniteelement(WFE)model:(i)Giventhe

damage model of the structure, the theoretical reflection/transmission coefficients can be

calculatedefficientlyusingWFEmodels.(ii)Theprobabilisticdistributionpropertiesofthe

reflection/transmissioncoefficientsestimatedusingmeasuredultrasonicguidedwavesinthe

frequency domain are inferred based on complex ratio statistics. (iii) Based on the

probabilistic distribution of reflection/transmission coefficients, the likelihood function

connectingthetheoreticalreflection/transmissioncoefficientscontainingtheparametersto

be updated and the measured reflection/transmission coefficients are formulated within a

unified Bayesian system identification framework. (iv) Kriging model that provides a

surrogatemappingbetweentheprobabilityspacesofthedamageparameterstobeidentified

andthetheoreticalreflection/transmissioncoefficientsareemployedtoreplaceasignificant

numberofrelativelytime-consumingWFEsimulationsrequiredinthelikelihoodevaluations

by very fast approximate estimates. (v) The transitional Monte Carlo Markov Chain in

conjunction with the kriging model is used to sample the posterior probability density

functionoftheupdatedparametersataveryreasonablecost.Twonumericalexamplesare

usedtoverifytheaccuracyandefficiencyoftheproposedalgorithm.Resultsindicatethatthe

fast-numerical strategies proposed in this study can improve the computational efficiency

significantly.



224

A0639-Anewstochasticfiniteelementmethodforstructuralmodelupdatingbased

onuncertainstaticdata

W.Zhifenga,H.Binb

aPhd,Wuhanuniversityoftechnology,e-mail:[email protected]

bProfessor,Wuhanuniversityoftechnology,e-mail:[email protected]

Thispaperproposedanewstochasticfiniteelementmethodforstructuralmodelupdating

basedonuncertainstaticdata.Basedonthestaticcondensationtechnique,astatisticalmodel

updating equation associated with element updated factors is established. A high-order

perturbationtechniqueisintroducedtoobtainthecoefficientsofthepowerseriesexpansions

of the element updated factors. The Tikhonov regularization and truncated singular value

decompositionareemployedintheprocessofmodelupdatingtosolvethediscreteill-posed

problems caused by measurement noise. The traditional stochastic perturbation model

updating method and Bayesian method based on delayed rejection adaptive Metropolis

algorithmareusedtocomparewiththeproposedmethod,whichcanvalidatethebenefitsof

theproposedmethod.Bothnumericalandexperimentalexamplesillustratetheaccuracyand

efficiencyoftheproposedmethodforfiniteelementmodelupdating.



225

A0641-GeneralizedTaylor-seriessolutionofeigenvalueofrandomstructure

H.Zhanga,B.Huangb

aWuhanUniversityofTechnology,Wuhan,China;e-mail:[email protected]

bWuhanUniversityofTechnology,Wuhan,China;e-mail:[email protected]

A new computational method is proposed for solving the eigenvalue of the structure with

randomparametersbasedontherecursivestochasticfiniteelementmethodandgeneralized

Taylor expansion. For this new method, the eigenvalues and eigenvectors of the random

structure are expanded as generalized Taylor-series. The deterministic coefficients in each

term of the generalized Taylor-series are obtained by recursive stochastic finite element

method,thentheapproachingfunctionwithauxiliaryparameterhisaddedineachterm.Due

totheparticipationoftheapproachingfunction,theconvergencedomainofthegeneralized

Taylor-seriesfortheeigenvalueisgreatlyimproved,whichmakesthisnewmethodavailable

forthelargefluctuationofrandomparametersanddifferentfromthetraditionalTaylorseries.

Numericalexampleinvolvingavariablecross-sectioncontinuousbeamindicatesthatthenew

method can provide excellent approximations of the eigenvalues compared with the

perturbationmethodandrecursivestochasticfiniteelementmethod.



226

A0751-AFractionalMomentMethodforReliabilityAnalysisofStructuresunderthe

SpatiallyVariability

XufangZhanga,QianLiu

aAssociatedProfessor,SchoolofMechanicalEngineeringandAutomation,Northeastern


Thereliabilityanalysisofanengineeringsystem,structureorcomponentistypicallybasedon

amodelthatdescribesthesystem'sresponse,suchasdeformation,asafunctionofapplied

loads,operatingenvironment,materialpropertiesandgeometryorconfiguration.Analytical

derivationofthedistributionofafunctionofrandomvariablesisfeasibleonlyinverysimple

cases and it is intractable problem in a general setting. Especially, the spatially varying

uncertaintycannotbehandleddirectlybymeansofstructuralreliabilitymethods.Thepaper

presentsageneralmethodtoderivetheprobabilitydistributionofamultivariatefunctionof

randomvariablesrepresentingtheresponseofastructure.Thederivationisanefforttotackle

the problem via the method of moment. However, a key departure is the use of fractional

momentsoftheresponsefunction,asopposedtointegermomentsusedsofarintheliterature.

Anewmultiplicativedimensionalreductionmethod(M-DRM)isproposedtoapproximatethe

originalcomplexinput-outputrelation.Anefficientnumericalmethodforfractional(integer)

momentcalculationwasfollowedbyusingM-DRMandGaussquadrature.Thesemi-analytical

probability distribution of structural output is determined using the principle maximum

entropy(MaxEnt)withtheconstraintsspecifiedintermsoffractionalmoments.Monte-Carlo

simulation was carried out to assess the accuracy of the proposed methodology. Examples

show that the results of the proposed method are fairly accurate as compared with the

benchmarksbycrudeMonte-Carlosimulation.



227

GS2: Computational Mechanics

A0031-COMPUTATIONAPPLICATIONDEVELOPMENTINSCIENTIFICPARADIGM

EchefuFrancisEmekaa

aLecturer,InstituteofManagementandTechnology,[email protected]

The era in computation application development in scientific paradigm has created new

opportunities for researchers to achieve high relevance, impact amid changes and

transformationsinhowwestudybasicsciencephenomena.Withtheemergenceofscientific

paradigmcollectiontechnologies,advanceddataminingandanalyticssupport,thereseemsto

befundamentalchangesthatareoccurringwiththeresearchquestionswecanask,andthe

research methods wecan apply. The contexts include social networks and blogs, political

discourse, corporate announcements, digital journalism, mobile telephony, home

entertainment, online gaming, financial services, online shop-ping, social advertising, and

social commerce.Computing is an evolving technological paradigm that facilitates

conveniently, on-demand network access to a shared pool of configurable computing

resourceslikenetwork,servers,storage,applicationsandservicesetcthatcanbepresented

asaserviceandreleasedwithminimalmanagementeffort.Themodelpromotesavailability

ofresourcesandcreatespowerfuldistributedcomputingsystemwithglobalreachandsuper

computing capabilities. Computing is enriching and will widen the horizon of human

knowledge, empower human capital for sustainable scientific development as well as

educationaldevelopmentofnations.Thispapertriestoexplorethevastandimmensebenefits

of computation development in scientific paradigm shift and its applications in e-library

servicesinAfricatoday.Thiswillallowbusinessanalystsandresearcherstoachievefrequent,

controlled and meaningful observations of real-world phenomena. I discussed how the

philosophyofscienceshouldbechanginginstepwiththetimes,andillustrateourperspective

withcomparisonsbetweenearlierandcurrentresearchinquiryinscientificparadigm.



228

A0063-ModelReductionTechniquesforDynamicSystemswithaLargeNumberof

LocalModes

XiaoshuZenga,OlivierEzvanb,BoraGencturkc,RogerGhanemd

aUniversityofSouthernCalifornia,LosAngeles,CA90089,U.S.A.,e-mail:[email protected]

bUniversityofSouthernCalifornia,LosAngeles,CA90089,U.S.A.,e-mail:[email protected]

cUniversityofSouthernCalifornia,LosAngeles,CA90089,U.S.A.,e-mail:[email protected]

dUniversityofSouthernCalifornia,LosAngeles,CA90089,U.S.A.,e-mail:[email protected]

Inacomplexsystemwithbothglobalmodesandmanylocalelasticmodes,thebehaviorofthe

local modes that are well-separated, usually has negligible effect on the global dynamics.

Takingadvantageofthisfact,anautomaticmodeselectionprocedureisfirstproposedtodraw

asubsetofdominantelasticmodesinthefrequencybandofinterestthatcanrepresentthe

global dynamics. This selection procedure is followed by a filtering technique that is

constructed by projecting the responses of the system onto a global displacement basis,

allowingenhancedaccuracyinthehighfrequencyrange.Subsequently,thesetwomethodsare

combinedwithsub-structuringtechniquestoallowforacomputationallyefficientanalysisof

systemswithlargesubstructures.Thetworeductionmethodsareappliedtoahomogeneous

platewith flexibleandstiffparts,asimplifiednuclear fuelassembly,andadetailedboiling

waterreactornuclearfuelassembly.Anotherapplicationofthecanister-fuelassemblymodel

isalsoexaminedtojustifycombiningglobalfilteringwithsubstructuretechniques.



229

A0102-GROUP-THEORETICEXPLOITATIONSOFSYMMETRYINCOMPUTATIONAL

MECHANICSOFNOVELPRESTRESSEDSTRUCTURES

YaoChena,JianFengb

aDr.,AssociateProfessor,SchoolofCivilEngineering,SoutheastUniversity,Nanjing,China,e-


bProfessor,SchoolofCivilEngineering,SoutheastUniversity,Nanjing,China,e-mail:

[email protected]

Symmetryisoneofthemostcommonandimportantfeaturesinnature.Differentsymmetry

canbeeasilyobservedfromamicroscopicviewtomacroscopicview,fromatomsandcrystals

to large-scale space structures. At the same time, innovative methods that consider the

inherentsymmetryofasystemwillbesystematicandeffective.Asan importantbranchof

mathematicsandvectoralgebra,grouptheoryisapowerfultoolforsystematicanalysison

symmetricsystems.Ithasbeenextensivelyappliedincomputationalphysics,computational

chemistry,andelectromagnetism.Inrecentyears,grouptheoryhasbeengraduallyadopted

forcomputationalproblemsofsolidandstructuralmechanics.Unfortunately,grouptheory

hasnotbeenwidelyadoptedincomputationalmechanicsofengineeringstructuresbecause

itisabstract(i.e.,mathematicallyrepresented)anduncommontomoststructuralengineers.

In addition, conventional symmetry mentioned in structural mechanics generally refers to

mirror symmetry or cyclic symmetry. This paper introduces the advances made in the

applicationofgrouptheoryincomputationalaspectssuchasstability,form-finding,natural

vibrationandbifurcationanalysisofnovelprestressedstructures.Asinitialprestressplaysan

important role in prestressed structures, its contribution to structural stiffness has been

considered. General group-theoretic approaches for the involved problems are presented,

where certain stiffness matrices and equilibrium matrices are expressed in symmetry-

adaptedcoordinatesystemandblock-diagonalizedneatly.Illustrativeexamplesonstructural

stabilityanalysis,force-findinganalysis,andgeneralizedeigenvalueanalysisoncabledomes

andcable-strutstructuresaredrawnfromrecentstudiesbytheauthors.Itshowshowgroup

theory,throughsymmetryspacesforirreduciblerepresentationsandmatrixdecompositions,

enablesremarkablesimplificationsandreductionsinthecomputationalefforttobeachieved.

More importantly, before any numerical computations are performed, group theory allows

valuable and effective insights on the behavior or intrinsic properties of a prestressed

structuretobegained.



230

A0188-EFFECTOFPOWERTAKE-OFFDAMPINGONHYDRODYNAMICEFFICIENCY

OFANOSCILLATINGWATERCOLUMNWAVEENERGYDEVICE

PiyushMohapatraa,AnirbanBhattacharyyabandTrilochanSahooc

aPh.D.Scholar,IndianInstituteofTechnology,e-mail:

Kharagpur,[email protected]

bAssistantProfessor,IndianInstituteofTechnology,e-mail:

Kharagpur,[email protected]

cProfessor,IndianInstituteofTechnologyKharagpur,e-mail:[email protected]

Oneofthesimplestandmostadvancedtechnologiestoharnessenergyfromtheoceanwaves

is the wave energy converter (WEC). A partially submerged semi-closed chamber

encompassesoceanwaterinsidethechamberwithanunderwateropeningtotheocean.Air

is trapped above the free surface inside the chamber. The incident ocean waves excite the

watermassinsidethechamberwhichgoesthroughupanddownmotionwithpassingcrests

andtroughs.Theupwardmovingwatercolumnpushesthetrappedairanddrivesitthrough

anarrowvent.Duringthedownwardmotionofthewatercolumn,alowpressureabovethe

freesurfacedrawsair fromtheatmosphere throughthevent.Apowertake-off(PTO)unit

which in this case is a unidirectional Wells type air turbine is placed in the vent which is

connected to a generator to generate electricity. However, the overall efficiency of these

systems is still not up to the mark for commercial electricity generation. With rapid

advancement in the computational facilities, Computational Fluid Dynamics (CFD) is now

recognizedasanimportantcomplementtotraditionalphysicaltestingtechniquesinocean

engineering. In the present study, numerical investigation of a shore fixed OWC device is

performedusingCFDtoolANSYSFluent.Amultiphasevolumeoffluid(VOF)modelisusedto

design a numerical wave tank (NWT) for simulation of wave generation in an ocean

environment.TheincidentwavescomefromoneendoftheNWTandimpingeontheOWC

chamberplacedontheoppositeendofthetank.Theresultsofwavegenerationarevalidated

with the previous numerical and theoretical results. The flow characteristics inside and

outsideoftheOWCchamberareanalyzed.Thedampingprovidedbytheairturbineismodeled

asflowthroughaporousmedia.Itreplicatesthepressurejump-flowbehaviorofaWells-type

air turbine. Both linear and non-linear models of turbine damping were considered and



231

simulations were carried out for different values of porous media parameters to study the

turbine pressure jump characteristics. The hydrodynamic efficiency of the OWC device is

calculated for different values of linear and non-linear turbine damping coefficients. The

hydrodynamic efficiency is plotted against incident wave frequency for various values of

turbinedampingcoefficients.Theresultswerecomparedwiththeresultsfromthepreviously

availableliterature.



232

A0211- WEAK ENFORCEMENT OF DISPLACEMENT CONDITIONS IN FICTITIOUS

DOMAINFINITEELEMENTANALYSIS

KaizhouLua,CharlesAugardeb,WilliamCoombsc,ZhendongHud

aPh.D.candidate,TongjiUniversity,e-mail:[email protected]

bProfessor,DurhamUniversity,e-mail:[email protected]

cAssociateprofessor,DurhamUniversity,e-mail:[email protected]

dProfessor,TongjiUniversity,e-mail:[email protected]

In fictitious domain finite element analysis, one of the major difficulties comes from

incorporatingDirichletboundaryconditions,as thegridnodesarenotguaranteed toalign

withthegeometricboundaryofthecomputationdomain.Unliketheclassicalfiniteelement

method,whereDBCscanbeimposednode-wisely,“weak”enforcementmethodsareemployed

asalternatives.InthediscontinuousGalerkinmethod,inwhichadjacentfiniteelementsdonot

have shared nodes, the similar weak enforcement (more often Nitsche’s method) is also

employedtoweaklyattachdisplacementsbetweenelements.Lagrangemultiplier,penaltyand

Nitsche's methods are well-developed approaches in this area that have inspired various

successors, with the recently developed linked-Lagrange multiplier and step boundary

methodsbeingtwoofthem.Herewepresentageneralintroductionofthesetwomethodsand

provide modifications with advantages. A number of numerical examples are provided to

validatetheaccuracyoftheproposedapproaches,withoptimalratesofconvergencehaving

beenachieved.



233

A0290- QUANTIFICATION OF ERROR IN COMPUTATIONAL MODELS BASED ON

THREE-DIMENSIONALMICROSTRUCTURECHARACTERIZATION

LoriGraham-Bradya,NoahWadeb

aProfessor,JohnsHopkinsUniversity,e-mail:[email protected]

bStudent,JohnsHopkinsUniversity,e-mail:[email protected]

Three-dimensionalmicrostructurescollectedbyexperimentalcharacterizationprovideboth

statistical information and the basis for computational models, which allows us to analyze

heterogeneous materials at small length scales. However, the collection of such three-

dimensionalmicrostructuraldatacommonlyreliesondestructivetechniques,suchasserial

sectioning,andsuchmethodsoftenprovidenoquantitativemeasureoftheaccuracyofthe

digital microstructure in representing the true physical specimen. This makes quality

assessmentofthedatasetsdifficultanditposesachallengetoidentifywhichcharacterization

parameterswillproduceoptimalefficiencyinthedatacollectionprocesswhilemaintaining

anacceptableleveloferrorintheresultingdata.Toaddressthisquestion,thispresentation

describes a computational method that was developed to simulate serial sectioning data

collection,basedonadigitalrepresentationofamaterial,calledaphantom.Bysimulatingthe

datacollectionanddataprocessingprotocolsofuserdefinedparameterssuchasresolution,

slicethickness,dwelltime,polishingmethod,etc.theeffectofeachonerrorpropagationcan

betrackedrelativetothefullyunderstooddigitalphantom.Thenbyvaryingeachparameter

theeffectscanbestudiedindividuallyandprovideboundsonboththecontributionsofeach

parametertotheerroraswellasthetotalerrorintroducedthroughtheexperimentalprocess.

This provides a quantitative method for comparing the relative trade off between

experimentalparameterssuchcollectingdataataveryhighresolutionvs.collectingdataover

alargevolume.Ultimatelythesemeasuresarethenutilizedaspartofanobjectivefunctionto

optimize the selection of experimental parameters. An example of optimization of

experimental data collection parameters for the acquisition of an 3D Electron Backscatter

Diffraction (EBSD) data set demonstrates how the error in computational models can be

reduced.



234

A0629- IMPLEMENTATION OF A MESH SENSITIVE-LESS APPROACH FOR THE

PSEUDO-LOWERBOUNDMETHOD

M.DeFilippoa,J.S.Kuangb

aPhDCandidate,DepartmentofCivilandEnvironmentalEngineering,TheHongKong

UniversityofScienceandTechnology,e-mail:[email protected]

bProfessor,DepartmentofCivilandEnvironmentalEngineering,TheHongKongUniversity

ofScienceandTechnology,e-mail:[email protected]

Intheearlyagesoflastcentury,plasticmethodsofanalysishavebeenintroducedassolution

for applications of the yield-line problem for Reinforced Concrete (RC) slabs. Such field of

researchhasshowngreatpotential for itsapplicationinindustry.Sofar,severalupperand

lowerboundmethodshavebeenproposed,butnoneofthemhaveprovedfullreliabilityyet.

Thecurrentresearchprojectisattemptingtofillthisgapandfocusesonthedevelopmentof

an innovative Pseudo-lower bound method for the assessment of RC slabs. The obtained

results have already reached a good fit with exact analytical solutions for simple cases,

howeverthealgorithmstillhasroomfor improvement. In thispaper, theproblemofmesh

sensitivityisaddressed.Themethodaimsatprovidinganoptimizedlowerboundedsolution,

whichisreachedthroughaniterativeapproachcarriedonwithamonotonicallyincreasing

load.Ayield-checkisperformedateachiterationwithinanincreaseofloadintensity.Theidea

istoassessthestrengthofeachsingleelementindividuallyinanautomatedmanner,hence

creating a localized yield-criterion which is dependent on the mesh size. Through such

improvement, the method would not be dependent on the mesh anymore since moment

capacitiesareadaptedtothesizeofeachsingleelement.Theoutcomeisameshsensitive-less

adaptationofthePseudo-lowerboundmethod,whichremovesitsdependenceonthemesh,

andtendstoincreasetheaccuracyofthesolution,hencepushingthelowerboundfurtherup.



235

A0661-MECHANICALPROPERTIESOFFILAMENTOUSNETWORKSINTERMSOF

THEIRMICROSTRUCTURE

HamedHatami-Marbinia

aMechanicaandIndustrialEngineeringDepartment,UniversityofIllinoisatChicago,

Chicago,IL,60607,e-mail:[email protected]

A randomly crosslinked polymer network forms the solid skeleton of many biological

structuressuchasthecytoskeletonandextracellularmatrixofsofttissues.Thecytoskeletal

networkwhichiscomposedofF-actin,microtubules,intermediatefilaments,bindingproteins,

anddifferentcross-linkfilamentsstabilizesthecellmorphologyandmodulatesitsfunction

such as its motility. Similarly, a network of collagen fibers forms the microstructure of the

extracellularmatrixandplaysanimportantroleindefiningthemechanicalpropertiesofsoft

tissues. Thus, it is necessary to investigate the mechanical properties of random fibrous

structures.Inthepresentstudy,wefocusontheroleofthemicrostructureandconnectivity

onthemechanicalpropertiesofthesenetworks.Tothisend,weusedifferentalgorithmsto

construct two- dimensional intertwined fibrous networks. For example, we create two

dimensional fiber network structures by randomly placing fibers of a given length and

orientationinasquaredomain.Rigidconnectionsaredefinedatallpointswherethefibers

cross and the fibers are assumed to have a bending and stretching stiffness. We then use

different non-affinity measure to quantify the mechanical behavior of these networks at

different length scales. We conclude that although the structure and connectivity have

important roles in defining the mechanics of these networks, their effects reduce with

increasingthefibernumberdensityandthebendingstiffnessofthefibers.



236

A0700- Analytical Calculation Method for Steel Gate Wide Flange I-Shaped Deep

BeamwithShearEffectofWholeSection

SiyuanWua,ZhengzhongWangb,XuecaiZhangc

aDoctor,StateKeyLaboratoryofDisasterReductioninCivilEngineering,TongjiUniversity,


bProfessor,ColdandAridRegionsWaterEngineeringSafetyResearchCenter,Northwest

A&FUniversity,e-mail:[email protected]

cDoctor,ColdandAridRegionsWaterEngineeringSafetyResearchCenter,NorthwestA&F


Transversalsectioneffectofsheardeformationonbendingnormalstressismoreprominent,

which leading to enormous calculation error used primary beam theory in the traditional

design,becausethefaceplateofhydraulicsteelgatecanbeusedastheflangeofthemainbeam,

andundertheactionofhigh-head,themainbeambearsthenonlinearstresscharacteristics

ofshortdeepbeams.Basedonenergy-variationalmethodwithsheardeformationenergyof

wholeI-beamsection,throughtherationalselectionofthelongitudinaldisplacementfunction

and the warping function, formulas are derived in this paper for the calculation of the

deflection,bendingnormalstressandnaturalfrequency.Onthisbasis,resultsarecompared

with those obtained by various analytical methods and the finite element numerical

simulation results. The results indicate that when span-depth ratio or span-width ratio is

small, the bending normal stress is affected greatly by the transverse shear, and it is more

significant under the concentrated load, but the shear effect reduces it when the natural

frequencyiscalculated.Besides,comparedwiththeexistinganalyticalmethods,theproposed

methodofiersmoreaccurateresultswithanextendedscopeofapplication,whichcanbeused

forthestructuraldesign.



237

A0983-AB-SCANSUBSURFACEIMAGINGOFGROUNDCAVITIESUSINGANELASTIC

WAVEFULL-WAVEFORMINVERSIONMETHOD

B.Kima,J.W.Kangb,S.H.Keec,H.Jeongd

aGraduatestudent,Departmentofcivilengineering,Hongikuniversity,

Seoul04066,RepublicofKorea,e-mail:[email protected]

bAssociateprofessor,Departmentofcivilengineering,Hongikuniversity,

Seoul04066,RepublicofKorea,e-mail:[email protected]

cAssistantprofessor,DepartmentofArchitectureEngineering,Dong-AUniversity,

Busan49315,RepublicofKorea,e-mail:[email protected]

dSeniorresearcherengineer,KoreaInfrastructureSafety&TechnologyCorporation,

Jinju52852,RepublicofKorea,e-mail:[email protected]

This paper discusses characterization of ground cavities by an elastic wave full-waveform

inversion(FWI)method.Theelasticwavesaregeneratedbyimpactsontheroadsurfaceand

theresultingsurficialresponsesofthegroundareinvertedforthecharacterizationofroad

cavities.Forthesimulationofelasticwaves,perfectly-matched-layer(PML)isintroducedasa

wave-absorbing boundary, which truncates the semi-infinite domain and removes artificial

reflectionsfromthetruncatedboundaries.TheFWImethodisbasedonapartial-differential-

equation-constrainedoptimizationapproach,whichcanbeimplementedwithKarhsh-Kuhn-

Tuckeroptimalityconditionsforminimizingtheobjectivefunctionalaugmentedbygoverning

elasticwaveequationsviaLagrangemultipliers.Toalleviatetheill-posednessoftheinverse

problem, Tikhonov and total variation regularization schemes are used. To investigate the

feasibility of the FWI method, field experiments were performed on testbed sites with an

artificialcubic-shapedcavityandwitharealroadcavity.Thecavitieshavebeensuccessfully

reconstructedbytheFWImethodusinggroundvelocitiesmeasuredonthepavementsurface.



238

GS3: Wood Mechanics

A0308- Development of An Andvanced Fe-Numerical Method for Strength

PredictionofTimberBoardsBasedontheSurfaceInformation

A.KhaloianSarnaghia,J-W.vandeKuilena,b,c

aDepartmentofWoodTechnology,TechnicalUniversityofMunich,80797Munich,Germany

bFacultyofCivilEngineeringandGeosciences,DelftUniversityofTechnology,Delft,

Netherlands

cGuestresearcher,CNR-Ivalsa,Florence,Italy

Full3Dreconstructionofthewoodenlaminationsisaninitialstepinthisstudyforfurther

numericalanalysis.Thisisdonebasedontheknotmeasurementsonthesurfacesoftheboards.

Theaimofthisstudyistodevelopanadvancedvirtualmethodforthestrengthpredictionof

theboards.Byknowingthelocationsoftheknots,asthemainstrengthgoverningparameters

in timber boards, simulations are run for large quality range of wood laminations. This

includes 137 low-medium quality Douglas fir, 103 medium-high quality spruce and some

hardwood boards. The laminations are then used for the numerical analysis of the glulam

composites.ABAQUSandPYTHONareusedforthenumericalsimulations.Anautomaticlink

isprogrammedtoextractthedataofthedatabaseandtocreatethegeometricalmodel.The

3DFE-Analysesofthegeometricallyreconstructedboardsaresuccessfullydoneinthisstudy.

Knotclusters,asmultiplegeometricalimperfectionsintimberboardsarecausinglocallized

highstresses,whichmayleadtotheinitiationofthefailureinthematerial.Therefore,three

mathematicalmethodsarepresentedfromthenumericalsimulationstocalculatethestress

concentration factors (SCFs) around the 3D heterogeneous defects in anisotropic wooden

boards.TheFEMresultsareusedinaregressionanalysistoanalyzethecorrelationswiththe

visualmeasurementsandtopredictthetensilestrength.Basedontheresultsofthemultiple

regressionanalysis,theSCFsaremuchstrongerstrengthpredictorscomparedtotheavailable

visualgradingparameters.Comparingthenumericalpredictionswiththeavailablemachine

gradingmethods,onlytheSCFvaluesaresufficienttopredictthestrengthofthegoodquality

spruce boards, and equally good correlations are found between both results for the low

qualityDouglasfirboards.Usingthedynamicmodulusofelasticityasanadditionalparameter

forthestrengthpredictionsimprovesthequalityofthepredictionssignificantly.Theresults

ofthecurrentstudyshowanimprovementinthestrengthpredictionofwood,basedonthe

numericalsimulationsthataresolelybasedonthegeometricalrepresentationoftheknots.



239

A0955-DEFORMATIONKINETICSFORWOODMECHANICS

J.W.G.vandeKuilena,b

aDepartmentofWoodTechnology,TechnicalUniversityofMunich,80797Munich,Germany

bFacultyofCivilEngineeringandGeosciences,DelftUniversityofTechnology,Delft,

Netherlands

DeformationKineticsisbasedonEyringequationsthatdescribetheinfluenceandinteraction

betweenmoleculesand howthese interactionprocessesare influencedbyexternal factors

suchasstressandtemperature.Anumberofresearchprojectshavebeencarriedoutinthe

world using the Eyring´s ground concepts of deformation kinetics. Short and long term

behaviourofwoodcanbedescribedbutitcanalsobeusedasabasistodescribeservicelife

behaviouroftimberstructuresasinfluencedbymechanical,physical,biologicalandchemical

degradationprocesses.Chemicalkineticshasimportantadvantagesoverstandardmicroscale

modelling in that it allows generalizations to multiple planes and scales, whereas

micromechanical modelling is limited to ´perfect wood´, without the influence of grain

deviations,knotsetc.Therefore,microscalemodellingofthemicrostructureofwoodcellsis

generallydescribedwithFEMmodelsorsimilarmodellingtechniquesthatneedsadaptionfor

natural wood failures as knots. Then, Monte-Carlo simulations are needed to account for

spatial variations in material properties. This problem does not occur with deformation

kineticsbecausedifferentreactionratesatthenano-,micro-,andmacrolevelareautomatically

accounted for.Themolecularbehaviour, interactions betweenmoleculesofdifferentorigin

within the wood, vibration behaviour as a function of temperature and last but not least

moisturecannotbeeasilyintegratedinFEMmodels.Applicationofthetheoryleadstovarious

solutionsforcreep,stressrelaxationandbondbreaking,alsoknownasdamageaccumulation.

Thedamageaccumulationtheorycanbeappliedonrealstructures,takingintoaccountcrack

formation,biologicaldegradationandmechanicalloadsatthesametime.Modelpredictions

canbeusedforriskanalysis,residualloadcarryingcapacityestimatesandevenmaintenance

planning.



240

A0957- AN INVESTIGATION OF THE DOL EFFECT OF WOOD´IN TENSION

PERPENDICULARTOGRAIN

EnchunZhua

aSchoolofCivilEngineering,HarbinInstituteofTechnology

Wood is a visco-elastic material. Strength of wood decreases under long-term load (DOL

effect).Currently,researchofDOLeffectofwoodintensionperpendiculartograinisnotas

muchasthatofparalleltograin.Inthisstudy,atotalof140NortheastChinalarchsmallclear

specimens were tested under long-term tension perpendicular to grain, in which the

specimenswereclassifiedintothreestresslevels.Theshort-termstrengthofspecimensofthe

matchedsamplewerealsotestedandcomparedwiththelong-termstrength,therelationship

betweenloadingtimeandthestrengthreductionwasthusobtained.Itwasfoundoutthatthe

DOLeffectoftensionperpendiculartograin, followingaconvextrendline,waslesssevere

thanthatpredictedbytheMadisoncurve.Also, thetestresultshowedthatDOLof tension

perpendicular to grain poses little effect on its modulus of elasticity. Four DOL models

includingtheFoschiandYaos’modelwerecalibratedwiththeexperimentaldataandthelong-

term strength was predicted by the calibrated DOL models. Finally, a refined FE model in

considerationofthegrowthringsandcreepofwoodwasdevelopedbasedonANSYS.ViaFE

simulation,thestressre-distributionwasrevealedandthefailuremechanismofwoodunder

long-termloadexplained.



241

A0960- AN INVESTIGATION OF FATIGUE FRACTURE OF WOOD DUE TO CYCLIC

MOISTURE_INDUCEDSTRESS

QiongyaoWua,EnchunZhua

aSchoolofCivilEngineering,HarbinInstituteofTechnology

Moisture-inducedstressinwoodwilloccurduetomoisturevariations.Inthisstudy,fracture

of wood due to moisture-induced stress was investigated in a point of view of the fatigue

problem.Fatiguetestsofwoodundercyclicmoisture-inducedstressperpendiculartograin

were conducted on small clear specimens of Scotch pine and Northeast China larch. The

crackingtimeandcrackingphenomenonofthespecimenswereobservedandexplained.AFE

modelwasdevelopedincorporationwithABAQUS,tosimulatethemoisture-inducedstress

inthespecimen.Theconstitutivemodelwasestablishedbyconsideringtheeffectsofthermal

expansion,viscoelasticcreepandmechano-sorptivecreep.ThesimplifiedLuikovheattransfer

modelandFick'ssecondlawofdiffusionwareemployedasthegoverningequationsforthe

heartandmoisturetransfer.TheFEmodelwasusedtosimulatethedistributionofmoisture

contentandmoisture-inducedstressunderdifferentspecimensize,humidityvariationperiod

andamplitude.Moreover,afatiguemodelwasdevelopedbasedontheDVMtheory,andthe

fatiguepredictionbythemodelwascomparedwiththetestresultsofthisstudy.Crackingof

woodduetocyclicmoisture-inducedstresswasthusexplainedfromafatiguepointofview.



242

A0968-VARIABILITYINWOOD/PLANTANATOMYALONGTHESCALES

W.F.Garda

aFacultyofCivilEngineeringandGeosciences,DelftUniversityofTechnology,Biobased

StructuresandMaterials,Delft,Netherlands

Plantsarecomplexcompositesofnaturalpolymers.Theydevelopfromlivingmicrocellsto

macro aggregates. Highly lignified plants such as gymnosperms (e.g. softwoods) and

angiosperms (e.g. hardwoods, bamboo) are converted to products which are used among

othersincivilengineeringassolids,fibresandchemicals.Themicroandmacrocomposition

and shape of plants are set by genetic dispositions and reflecting the growth conditions

characterizedbyclimate, soilandexternal loads.Aplant isadynamiccompositestructure

whichreactsandadaptsforexampletowindloads,damagesetc..Thatresultsinamaterial

withaclearlyinhomogeneouscompositestructure.Causedbythenatureofplantgrowth,the

structurehasadistinctorientationoftheplantelementssuchasfibres,vesselsandrays.For

examplevesselsareintendedtotransportwaterfromthesoilviarootsuptotheleavesofthe

plant.Theyareorientedinverticaldirectionasastronglyconnected‘pipenetwork’.Incontrast

raysareorientedhorizontallyandprovidingcellswithwaterandnutrientsinradialdirection.

These composite structures lead to anisotropic behavior of the plant elements. Most

importantplants forcivilengineeringapplicationsaresoftwoods,hardwoodsandbamboo.

The anatomical elements are built up of organic polymers compiled to microfibrils which

progress to cell walls, fibres and finally solid material (e.g. wood, bamboo). The cell wall

consistsofthreemainchemicalcomponents,cellulose,hemicelluloseandligninwithpolymer

dimensions between 10-10 m and 10-9 m. These elements are composed to cell wall layers

whichformsthecellwall(thickness10-6m).Thecellwallcompositedeterminesthephysical

andmechanicalpropertiesofthesinglefibre.Furthermoretheorientationandtheinterface

adhesion between the fibres define the properties of the sound solid material. It has been

demonstratedthatsinglecellulosechainmoleculehasa15timeshighertensilestrengththan

single fibre which is caused by the weak interface actions between layers. However the

complexity of the anatomical elements explains the highly inhomogeneity and anisotropic

behaviorofthewoodandthewidescatterofmechanicalandphysicalpropertieswithinthe

samewoodspeciesevenfromthesameorigin.



243

GS4: Structural Mechanics and Simulation

A0164- HYBRID INTELLIGENCE FOR SOLVING COMPLEX ENGINEERING

PROBLEMS:ANINTEGRATEDHUMANANDMACHINELEARNINGAPPROACH

YongmingLiua,YangYub,andHoupuYaoc

aProfessor,SchoolforEngineeringofMatter,Transport&Energy,ArizonaStateUniversity,e-


bPostdoctoralFellow,SchoolforEngineeringofMatter,Transport&Energy,ArizonaState


cPh.D.candidate,SchoolforEngineeringofMatter,Transport&Energy,ArizonaState


Thisstudyproposestheconceptofhybridintelligence,aphysics-basedlearningapproachthat

integratesmachinelearningandphysics(humanintelligence),asacomputationallyefficient

methodforsolvingcomplexengineeringproblems.Thephysics-basedlearningencodesthe

underlying physics of engineering problems into machine learning models such as

convolutionalneuralnetworks(CNNs)andrecurrentneuralnetworks(RNNs)toreducethe

trainingandsimulationcosts.Theapplicationofphysics-basedlearningisdemonstratedon

simulatingpartialdifferentialequations(PDEs)andordinarydifferentialequations(ODEs)in

engineeringsystems.Firstly,arecentlyintroducedphysics-awarenetworkknownasthedeep

residual RNN (DR-RNN) is introduced for solving structural dynamic problems. A 10-story

shear building subject to earthquake excitations is used to demonstrate the computational

efficiencyofthephysics-basedlearningapproach.Secondly,weintroduceaFEA-Net,whichis

inspiredbyFiniteElementAnalysis,tosolvethree-dimensional(3D)heattransferproblems

anddemonstrateitsimprovementsindataefficiencyandmemoryconsumption.



244

A0259- A PARALLEL SPECTRAL ELEMENT METHOD FOR THE SIMULATION OF

SCALARELASTICWAVES

S.Youna,J.W.Kangb,H.Ryuc

aGraduatestudent,DepartmentofCivilEngineering,HongikUniversity,Seoul,Republicof

Korea,e-mail:[email protected]

bAssociateprofessor,DepartmentofCivilEngineering,HongikUniversity,Seoul,Republicof


cPrincipalResearcher,NationalInstituteofSupercomputingandNetworking,KoreaInstitute

ofScienceandTechnologyInformation,Daejeon,RepublicofKorea,e-mail:

[email protected]

Thispaperdiscussesanexplicitspectralelementmethodforthesimulationofscalarelastic

waves in semi-infinite domains. To simulate the wave propagation in unbounded domains,

perfectlymatchedlayer(PML)isintroducedasawave-absorbingboundarythatsurrounds

thefinitecomputationaldomainofinteresttruncatedfromtheoriginallysemi-infiniteextent.

For numerical implementation of governing scalar wave equations in the PML-truncated

domain,semi-discreteequationsofmotionareconstructedbyusingmixedspectralelements

withtheLegendre-Gauss-Lobattoquadraturemethod,whichenforcesthemassmatrixtobe

effectivelydiagonalized.Thesemi-discreteequationsofmotionaresolvedbythefourth-order

Runge-Kuttamethodfordisplacementandstresses.Thedevelopedspectralelementmethod

has been applied to parallel computing based on message passing interface (MPI), which

demonstrates the feasibility of the proposed method to solving large-scale elastic wave

problems.



245

A0267- A NUMERICAL STUDY ON THE THERMO-MECHANICAL RESPONSE OF A

COMPOSITEBEAMEXPOSEDTOFIRE

M.S.Kanga,H.Pakb,J.W.Kangc

aGraduatestudent,DepartmentofCivilEngineering,HongikUniversity,Seoul,

RepublicofKorea,e-mail:[email protected]

bResearchassistant,DepartmentofCivilEngineering,HongikUniversity,Seoul,

RepublicofKorea,e-mail:[email protected]

cAssociateprofessor,DepartmentofCivilEngineering,HongikUniversity,Seoul,Republicof


Thispaperdiscussesananalyticalframeworkforestimatingthethermo-mechanicalbehavior

ofacompositebeamexposedtofire.Theframeworkinvolves:afiresimulationfromwhichthe

evolutionoftemperatureonthestructuresurfaceisobtained;datatransferbyaninterface

model, whereby the surface temperature is assigned to the finite element model of the

structure for thermo-mechanical analysis; and nonlinear thermo-mechanical analysis for

predictingthestructuralresponseunderhightemperatures.Weuseaplastic-damagemodel

forcalculatingtheresponseofconcreteslabs,andproposeamethodtodeterminethestiffness

degradation parameter of the plastic-damage model by a nonlinear regression of concrete

cylinder test data. To validate simulation results, structural fire experiments have been

performedonareal-scalesteelconcretecompositebeamusing the fire loadprescribedby

ASTM E119 standard fire curve. The calculated evolution of deflection at the center of the

beamshowsgoodagreementwithexperimentalresults.Thelocaltestresultsaswellasthe

effective plastic strain distribution and section rotation of the composite beam at elevated

temperatures are also investigated. For fire behavior simulation of the composite beam

protected by fire-resisting materials, the reduction of heat transfer coefficient from the air

layer to the beam is implemented. The series of numerical results demonstrates that the

proposed method of structural fire analysis is suitable for predicting the fire behavior of

compositebeams.



246

A0310-TheoreticalStudyOnVibrationOfASimplySupportedFootbridgeUnder

DiscretePedestrianLoading

Shih-HsunYina

aAssociateProfessor,DepartmentofCivilEngineering,NationalTaipeiUniversityof

Technology,Taipei,Taiwan,e-mail:[email protected]

An analytical approach is presented to analyze pedestrian-induced vibration of a simply

supportedbeam.Inthisstudy,discretepedestrianloadingmodelsareproposedtosimulate

each footstep load induced by a pedestrian who walks or runs. The footstep loads act at

differentlocationsalongthebeam,dependingonasteplength.Theloadingtimehistoryofan

individualfootstepisdeterminedbyadifferentforcepulse,dependingonwalkingorrunning.

Based on the analytical approach, relations between the beam response and the pacing

parameters including a pacing period, footstep contact duration, and step length are

theoreticallyinvestigated.Also,theresultsofvibrationestimationofasimplysupportedbeam

underverticalpedestrianloadingshowthattheproposedpedestrian-inducedloadingmodels

aremorereasonablethanthemovingloadmodelusedincurrentfootbridgedesignguidelines.



247

A0467- IMPACT LOCATION AND LOAD IDENTIFICATION USING DEEP NEURAL

NETWORKS

JiamingZhoua,LongleiDongb

aXi'anJiaotongUniversity,Xi'an,Shaanxi,710049,P.R.China,e-mail:[email protected]

bXi'anJiaotongUniversity,Xi'an,Shaanxi,710049,P.R.China,e-mail:[email protected]

Identifyingthelocationandhistoryofimpactforceappliedonmechanicalstructuresisvery

important for dynamic design, vibration control, reliability analysis as well as condition

monitoring.Unfortunately,therearemanypracticalsituationswherethedirectmeasurement

ofimpactforcesisnoteasytocarryout,somanyindirectidentificationmethods,includingthe

inverse method, the optimization method, and the neural network method, have been

presentedusingdynamicresponsestypicallymeasuredbyaccelerometersorstraingauges.In

this paper, a new identification method of impact load is proposed based on deep neural

networktechnology.Theloadlocationisdeterminedbyarecurrentneuralnetwork(RNN)

with three-layer long short-term memory (LSTM), and the impact history is evaluated by

three-layerRNNmodelmainlyincludingsingle-layerBLSTM(bidirectionalLSTM)andtwo-

layerLSTM.BLSTMlayerisindispensablebecauseit’shighagreementwiththephysicalreality

ofstructuralvibration.Onlyonemeasuredpoint isused inourresearchandthepredicted

accuracyisnotdependentonthepositionofaccelerometers,whichshowsgreatadvantage

comparedwithothermethods.Besides,somecomplexpreprocessing,likefeaturesextraction,

isnotnecessaryforthismethodandsignaltruncationisappliedforcomputingefficiency.The

impactloadidentificationapproachisqualifiedthroughthesimulatedstudiesforathinplate

structureanddifferentnoiselevelsareconsidered.Inordertocountertheill-posedproblem,

adataaugmentationmethodisadoptedwhichcanidentifytheloadwithhigh-levelnoise.A

GPU-acceleratedlibrary,cuDNN,isusedtotrainthedeeplearningmodelandsearchforthe

optimalhyper-parameters.Theresultsshowthatthelocationandhistoryoftheimpactload

canbeidentifiedaccuratelyusingthepresentedmethod.Thisapproachprovidesaneffective

and feasible way for impact load identification and more engineering structures will be

studiedinthefuture,likelaminatedcompositedplates,complexnonlinearsystems.



248

A0512-ULTIMATECAPACITYOFBULGEFORMEDT-JOINTSUNDERBRACEAXIAL

COMPRESSIONEXCLUDINGTHECHORDLENGTHEFFECT

FeilongNiea,QingZhangb,XianrongQinc,YuantaoSund

aSchoolofmechanicalengineering,TongjiUniversity,Shanghai,China,[email protected]

bSchoolofmechanicalengineering,TongjiUniversity,Shanghai,China,[email protected]

cSchoolofmechanicalengineering,TongjiUniversity,Shanghai,China,[email protected]

dSchoolofmechanicalengineering,TongjiUniversity,Shanghai,China,[email protected]

An innovativestiffenedtubular jointcalled thebulge formed jointhasbeendevelopedand

usedinpracticeforthefirsttime.Thoughitsgreatadvantageontheultimatecapacityhad

been proved by authors before, however, no parametric equation was available for the

ultimate capacity prediction. In this study, the finite element (FE) method and a real scale

specimentestwereemployedfortheinvestigationoftheultimatecapacityunderthebrace

axialcompressiveloading,andonlythelengthofjointitselfwasconsideredtoavoidtheoverall

chord length effect. Verified by the test, 27 FE models designed according to the Taguchi

methodologywereusedtoinvestigateeffectsofthegeometricparameters(β,γ,τ,τs,η1,η2)

on the ultimate capacity. Then excluding the parameter η2 whose effect on the ultimate

capacity was found negligible, 324 FE models designed based on the full factorial design

approachwereanalyzedtoderivetheparametricequationfortheultimatecapacity.Byalarge

amountofthenonlinearregressionanalysis,theparametricequationwasderivedwithhigh

accuracy.Theproposedparametricequationcanbeusedfortheultimatecapacityprediction

forthebulgeformedT-jointsunderbraceaxialcompressiveloadingexcludingthechordlength

effect.



249

A0595- EXPERIMENTAL ANDNUMERICAL STUDIES OF RESONANCE VIBRATION

OFCABLESINAFOOTBRIDGEMODELUNDERBIHARMONICEXCITATION

W.Pakosa,J.Groselb

aPhD,FacultyofCivilEngineering,WrocławUniversityofScienceandTechnology

WybrzeżeSt.Wyspiańskiego27,50-370Wrocław,Poland,e-mail:

[email protected]

bPhD,FacultyofCivilEngineering,WrocławUniversityofScienceandTechnology,Wybrzeże

St.Wyspiańskiego27,50-370Wrocław,Poland,e-mail:[email protected]

Themethod forreducingresonantvibrationsofstaycables inacablestayedbridgeunder

biharmonicexcitation isdescribed; it isanewmethoddevelopedbytheauthors.Research

results indicate that resonant vibration occurring simultaneously in any two pairs of stay

cablescanbeeffectivelyreducedbychangingstatictensionforcesinappropriatelyselected

stay cables. The selection of cables subjected to the change of static tension forces was

performedonthebasisofsensitivityanalysisofeigenproblemformulatedinaccordancewith

secondordertheoryandoflinearoptimization.Themethodwastestedbothonalaboratory

model of a cable-stayed footbridge and on a numerical (FEM) model of a cable-stayed

footbridgehavinggeometricalandmaterialparametersofarealbridgestructure.Itwasfound

that the change in the cable tension force needed to achieve an effective level of vibration

reductiondoesnotexceedtheUltimateLoadStateorServiceabilityLoadStateoftheobject.

Thisstatementisextremelyimportantasitemphasizesthepossibilityofpracticalapplication

oftheproposedmethodofvibrationreduction.Thegreatadvantageofthevibrationreduction

methoddiscussedhereisthatthereisnoneedtodeterminethecausesofexcessivevibration

associated with excitation. The idea behind the method is to counteract the sources of the

resonancephenomenonbychangingthevalueofthestructure’seigenfrequencyandnotthe

frequencyofexcitation.Theproposedmethodisalsoeffectiveinthecaseoflongcableswhen

passiveandsemi-activevibrationeliminatorsmountedneartheanchoragebecomeineffective.

Theproposedmethodcanserveasanalternativetocommonlyappliedmethodsofvibration

reductionwhichusevibrationdampersandeliminators.



250

A0721-non-linearnumericalanalysisonOverallprocessmechanicalbehaviorof

quasi-rectangularsegmentaltunnellining

XianLiua,ZhenLiub,HerbertA.Mangc

aProfessor,CollegeofCivilEngineering,TongjiUniversity,e-mail:[email protected]

bMastercandidate,CollegeofCivilEngineering,TongjiUniversity,e-mail:

[email protected]

cProfessor,InstituteforMechanicsofMaterialsandStructures,ViennaUniversityof


A segmental tunnel lining structure with a novel type of cross-section named quasi-

rectangularisutilizedforthefirsttimeinNingbo,China,asshowninFigure1/a).Thecross-

section is composedof tenblocks(T1,C1,B3,B2,C3,T2,C2,B1,LandF) andan interior

column(LZ).Tenblocksareconnectedbylongitudinaljoints(fromNo.1jointtoNo.10joint).

Three full scale tests have been conducted to investigate the mechanical behavior of the

structure under unexpected circumstance, such as overburden condition, where soil

overburden acts on the top of the tunnel. Based on experimental results of the tests, a

nonlinear finite element method is developed. The model of the structure is composed of

blocks, the interior column, longitudinal joints and a rigid zone. Geometric and material

nonlinearityoftheincludedcomponentsintheelasticandplasticphasesareconsidered.As

showninFigure1/b),theblocksandtheinteriorcolumnaresimulatedbyfiber-integration

beamelements,andthelongitudinaljointsaresimulatedbybeam-springelements.Thecross-

sectionoftheTblockincreasesatitsconnectingparttotheinteriorcolumnanditismuch

stifferthantheneighboringsegment.Therefore,itisidealizedtobearigidzone.Assuch,it

doesnotdeform,butitcanundergoarigidbodydisplacement.Thencomparisonbetweenthe

experimentalandnumericalresultsismade,payingspecialattentiontothefailureprocess,

thedeformationofthelongitudinaljointsandthestrainofthebolts.Theresearchhasshown

that: (1) the non-linear numerical model can accurately simulate the overall mechanical

behavior of the structure and the mechanism of the longitudinal joints, (2) the failure

mechanismofthestructurebeginswithfailureofthelongitudinaljoints.Finally,thestructure

losesbearingcapacity,whichisduetothefactthatshearbearingfailureofTblocksegment

occurs.Accordingtotheanalysisresults,thefailuremechanismofthestructureisdetermined

by the ultimate bearing capacity of the longitudinal joints and the segments, (3) the ideal

failuremodeofthequasi-rectangularsegmentaltunnelliningistoguaranteethatfailureof

the longitudinal joints is earlier than failure of the segment. Therefore, the failure of the

structure is characterized by ductile damage, which results in a high safety reserve of the

structureunderunexpectedcircumstances.



251

A0740-VIBRATIONCONTROLBYNONLINEARBOUNDARYABSORBERS

XiaoyeMaoa,HuDingb,Li-QunChenc

aShanghaiInstituteofAppliedMathematicsandMechanics,ShanghaiUniversity,Shanghai


bShanghaiInstituteofAppliedMathematicsandMechanics,ShanghaiUniversity,Shanghai


cDepartmentofMechanics,ShanghaiUniversity,Shanghai200444,China,e-mail:

[email protected]

Anonlinearlytorsionalabsorberassembledintheboundaryisproposedforakindofsimply

supported flexible structures. It not only maintains the advantage of the classic nonlinear

absorber,butalsohasacompactstructureandacertainmotionspace.Insimpleterms,the

absorberabsorbsthevibrationenergyviatherotatingangleattheendofthestructure.Then

theenergyisdissipatedbythedamper.Thedampercanbeassembledbetweentheoscillator

andthegroundorbetweentheoscillatorandthestructure.Thefirstoneoffersanonlinear

dampinganddoesn’tappearintheboundarywhilethesecondoneprovidesalineardamping

andappearsintheboundarydirectly.Asaresult,thefirstcasehasnoinfluenceonthelinear

characteroftheoriginalstructure,especiallytheanti-resonance,whilethesecondcasecan

changethem.Butontheotherhand,thesecondcasecanrestrainthevibrationdirectly.The

difficulty for the investigation to these two absorbers is how to deal with the nonlinear

boundaryanalytically.Thedirectmethodofmultiplescales,themethodofmodecorrection

andthemethodofharmonicbalanceareappliedatthesametimetoovercomethisproblem.

Thedifferentialquadratureelementmethodisusedtoverifyanalyticresults.Althoughthe

simulationmethodismoreaccuratethantheanalyticprocess,theanalyticprocedureismore

effective in optimizing the absorber. Based on the investigation, we find that the energy

transmitstotheabsorberalmostunidirectionalandthevibrationofthestructureisdeduced

byalmost90%oftheoriginalresonance.Thenonlinearlytorsionalabsorberintheboundary

providesaneweffectivestrategyforthevibrationcontrol.



252

A0903-UnderstandingUncertaintiesfromCyclicTestsofShapeMemoryAlloyBars

forSeismicApplication

JinpengLia,ChengChena,HetaoHoua,CanxingQiua

aJinan250061,ShandongProvince,People’sRepublicofChina,SchoolofCivilEngineering,

ShandongUniversity,e-mail:[email protected]

Shape-memory alloys (SMAs) has the super-elasticity therefore presents promising

application in vibration control of buildings and bridges subjected to seismic loads. The

properties of SMA are often determined through optimization method and treated as

deterministicfordynamicanalysisofstructureswithSMAbaseddevices.Thisstudyutilizes

the Metropolis-Hasting algorithm to characterize the uncertainties in model parameters of

SMA material. The probabilistic characterization presents potential correlations between

model parameters, and offers insight into the uncertainty in SMA behavior under seismic

excitation.AseriesofSMAbarswiththesamegeometricsizeandheattreatmentweretested.

ThebehaviorofSMAbarswerestudiedundercyclic loads.TheMarkovChainMonteCarlo

(MCMC)methodisappliedtoanalyzetheuncertaintiesofSMAintermsofmodelparameters,

equivalentdamping,andrecenteringcapability.



253

GS5: Bio-Mechanics and Bone Mechanics

A0667-THERELATIONOFCORNEALHYDRATIONANDSTIFFNESSIMPROVEMENT

BECUASEOFTHECORNEALCROSSLINKINGTREATMENT

HamedHatami-Marbinia,SandeepJayarama

aMechanicaandIndustrialEngineeringDepartment,UniversityofIllinoisatChicago,Chicago,

IL,60607,e-mail:[email protected]

Corneaisatransparenttissuethatisnecessaryforprovidingclearvisionandshieldingthe

intraocularcomponentsof theeye fromexternaldamage.Keratoconus isacornealdisease

whichaltersthemicrostructuralorganizationofthecollagenfibrilsandsubsequentlydamage

the structural integrity of the tissue. The loss of corneal structural integrity results in its

progressivethinningandassumingaconicalshapebecauseoftheintraocularpressure.The

cornealcollagencrosslinkingisatreatmentproceduretohalttheprogressionofthedisease.

Inthisprocedure,collagencrosslinksareintroducedinsidethestormainordertostrengthen

the mechanical properties of the corneal tissue. The commonly used collagen crosslinking

procedureiscomposedofsoakingthetissueintheriboflavinsolutionandthenexposingthe

tissuetoUVAirradiation.TheUVAraysdamagetheendothelialcells if thethicknessofthe

corneais lessthan400microns.Thus, it issuggestedtosoakthecorneasinhypoosomolar

solution(whichcausesexcessivecornealswelling)inordertotreatpatientswiththincorneas.

Despitethesuccessofthisalternativecrosslinkingprocedure,itisnotyetknownhowitwill

affect its strengthening effects if an isoosmolar solution is used. In the present study, the

porcine corneas were swollen to different thickness levels before crosslinking. Crosslinked

corneaswerethenbiomechanicallytestedtocharacterizetheirtensilestrengthusingaDMA

machine. The amount of stiffening due to the collagen crosslinking treatment was fully

characterizedasa functionof their initialhydration. Itwasobservedthat theextentof the

stiffeningofthecrosslinkingtreatmentwasindependentofthehydrationlevelatwhichthe

corneal samples were crosslinked when the tensile measurement was done at normal

hydration levels. The experimental observations were explained by a mathematical model.

ThefindingsofthepresentstudyfurthersupportedtheideaofusingthemodifiedUVcorneal

crosslinkingintreatingpatientswiththinkeratoconiccorneas.



254

A0870-A3-DimensionalModellingComparisonof theBiomechanicalStabilityof

LateralLumbarInterbodyFusionwithUnilateralorBilateralFixationMethod

TengZhanga,SiweiBaib,ChrisFanga,Tak-ManWonga,JasonCheunga,WilliamLua,Ashish

Diwanc

aDepartmentofOrthopaedicsandTraumatology,QueenMarryHospital,TheUniversityof

HongKong,HongKong,e-mail:[email protected];

bDepartmentofElectricalandComputerEngineering,TechnicalUniversityofMunich,

Munich,Germany,e-mail:[email protected]

cSpineService,StGeorgeHospital,Sydney,Australia,e-mail:[email protected]

In treating recalcitrant low pain or spinal deformity using interbody fusion, unilateral and

bilateralfixationmethodshaddemonstratedsimilarclinicalefficacy.Finite-elementanalysis

oflumbarbiomechanicsisperformedinthisstudytoinvestigatetheunderlyingmechanisms

ofunilateralversusbilateralfixation.TheanonymisedCTscansofahumanlumbarspinefour

and five (L4 and L5) were acquired at the Department of Orthopaedics and Traumatology,

QueenMarryHospital,theUniversityofHongKong,withanisotropicspatialresolutionof1

mm.ThesegmentationoftheCTscanswasperformedin3DSlicer,anopen-sourceplatform

formedicalimageprocessing,whichresultedinsurfacetriangularmeshesofthetwolumbar

vertebrae L4 and L5, as well as their major spinal stability structures, i.e. the anterior

longitudinalligamentandfacetjoints.Acylinderwithalengthof45mmandadiameterof5.5

mmwasbuiltasanidealizedshapeofthepediclescrewimplant.Thescrewswereinserted

intothelumbarvertebraeatthesamepositionssimulatingthesurgery,andconnectedbya

third cylinder representing the rod with a radius of 5.5mm. An interbodycage, created in

SolidWorks, was later placed between the bodies of the two vertebrae. Subsequently, all

surfacemeshes(Figure1)wereconvertedinGeomagicStudio(3DSystems,NC,USA)intonon-

uniformrationalbasisspline(NURBS)surfacepatchesthroughaseriesofmanualprocedures.

ThesurfacemodelswereimportedtoCOMSOLMultiphysics(COMSOLAB,Sweden),across-

platformfinite-element(FE)solver,fortheanalysisofthestressconditionwithbothunilateral

andbilateralfixationmethods.



255

The 5th EMI International Conference 2019

Wearepleasedtoinviteyoutothe5thEMIInternationalConference2019,inLyon,France.

ThetopicsoftheconferencearerelatedtoCivilandMechanicalEngineeringfieldswithan

interest on cross- and/or multi-disciplinary fields such as Material and Environmental

Sciences,ITandBigDataanalysis,SocialimpactofNaturalHazardsetc.

ThisConferencewillprovideauniqueopportunityforinternationalresearchersandindustry

experts to discuss recent results and developments in their fields of interest for mutual

benefits. Approaches combining experiments, modeling and/or simulations including the

influence of the boundary conditions (in situ experiments or simulations) and fabrication

processareverywelcome.

WithanveryefficienttransportationsystemandeasilyconnectedfromForeigncolleagues,

the City of Gastronomy is rich in historical and cultural attractions, INSA Lyon is looking

forwardtowelcomingyou!

AliDAOUADJI, on behalf of the organizing team.

What are the topics?

AsfortheannualEMIconferences,theEMIICLyon2019staysinlinewithitslong-standing

tradition as the prime venue for disseminating the most recent progress in Engineering

Mechanics as the core discipline of science-enabled Civil Engineering and Mechanical

Engineering as well. Mutual benefit are coming from cross and multi-disciplinary fields

combining

Conference venue

LyonTechLaDouaCampusandINSALyon’sfacilitieswillwelcomeyouduringyourstay.There

are numerous hotels downtown in Lyon located in very beautiful neighbourhoods and in

Villeurbannetoo.

GoodaccesstotheairportsofLyonSaint-ExupéryandParis-CharlesdeGaulleandParis-Orly,

aswellastothecentralstationusinghighspeedtrainsTGV,isprovided.TaketheTramways

T1orT4andyouwillreachtheCampus.



256

Who are the organizers?

EMI International Conference is organized under the auspices of Engineering Mechanics

Institute(EMI)whichisaDepartmentoftheAmericanSocietyofCivilEngineers(ASCE).The

LocalandInternationalScientificCommitteesaregivenintheWebsite

(emilyon2019.sciencesconf.org)

We’ll keep you informed.

All informationconcerningtheconferencevenue, lodging,registration, fees,mini-symposia

andabstractsubmissionandtheprogramwillbeprovidedsoonontheconferencewebsite

emilyon2019.sciencesconf.org.Feelfreetopassthisannouncementtoanyonewhomightbe

interested.

See you in Lyon next July!

Dates&deadlines

15September2018Mini-Symposiumsubmissionopens

1October2018Conferenceregistrationopens

1December2018Abstractsubmissionopens

28February2019Abstractsubmissioncloses

1April2019Notificationtoauthorsonacceptance

2July2019Arrival&registration,Icebreakerevening

3-5July2019EMIInternationalConferenceLyon



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November 2th, Friday

14:00--21:30 Registration (The 3rd floor of Kingswell Hotel VIP Room)

19:00--21:00 Ice Breaker Reception

November 3th, Saturday

8:00--18:00 Registration (Sino-French Center Room C201)

8:30--8:50 Welcoming Remarks

8:50--9:00 Group Photo

9:00--10:20 Plenary Lectures

9:00--9:40

Prof. Zdeněk P. Bažant

Lecture title: Design of New Materials and Structures to Maximize Strength at Probability

Tail: A Neglected Challenge for Quasibrittle and Biomimetic Materials

9:40--10:20Prof. Hai-Yan Hu

Lecture title: Engineering Dynamics of Soft Machines

10:20--10:40 Coffee Break

10:40--12:10 Technical sessions

12:20--13:30 Lunch

14:00--14:40 Plenary Lecture

Prof. Jin-Guang Teng

Lecture title: Mechanics of interfaces in FRP-strengthened structures




18:30--21:00 Banquet

November 4th, Sunday

8:30--9:50 Plenary Lectures

8:30--9:10Prof. Herbert Mang

Lecture title: Multiscale Analysis of Concrete StructuresA Joint Research Project of Tongji University and Vienna University of Technology

9:10--9:50Prof. Lori Graham-Brady

Lecture title: Uncertainty propagation from materials characterization to modeling



12:20--13:30 Lunch

14:00--14:40 Plenary Lecture

Prof. Jiun-Shyan (JS) Chen Lecture title: Meshfree Methods: Progress Made After 20 Years and Future Directions


16:05--16:25 Coffee Brea


Program At A Glance

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