Conference Proceedings of the Society for Experimental Mechanics Series Shamim Pakzad Editor Dynamics of Civil Structures, Volume 2 Proceedings of the 38th IMAC, A Conference and Exposition on Structural Dynamics 2020 Conference Proceedings of the Society for Experimental Mechanics Series SeriesEditor KristinB.Zimmerman,Ph.D. SocietyforExperimentalMechanics,Inc., Bethel,CT,USA TheConferenceProceedingsoftheSocietyforExperimentalMechanicsSeriespresentsearlyfindingsandcasestudiesfrom a wide range of fundamental and applied work across the broad range of fields that comprise Experimental Mechanics. SeriesvolumesfollowtheprincipletracksorfocustopicsfeaturedineachoftheSociety’stwoannualconferences:IMAC, AConferenceandExpositiononStructuralDynamics,andtheSociety’sAnnualConference&Expositionandwilladdress criticalareasofinteresttoresearchersanddesignengineersworkinginallareasofStructuralDynamics,SolidMechanics andMaterialsResearch. Moreinformationaboutthisseriesathttp://www.springer.com/series/8922 Shamim Pakzad Editor Dynamics of Civil Structures, Volume 2 Proceedings of the 38th IMAC, A Conference and Exposition on Structural Dynamics 2020 Editor ShamimPakzad DepartmentofCivil&EnvironmentalEngineering LehighUniversity Bethlehem,PA,USA ISSN2191-5644 ISSN2191-5652 (electronic) ConferenceProceedingsoftheSocietyforExperimentalMechanicsSeries ISBN978-3-030-47633-5 ISBN978-3-030-47634-2 (eBook) https://doi.org/10.1007/978-3-030-47634-2 ©TheSocietyforExperimentalMechanics,Inc.2021 Thisworkissubjecttocopyright.AllrightsarereservedbythePublisher,whetherthewholeorpartofthematerialisconcerned,specificallytherights oftranslation,reprinting,reuseofillustrations,recitation,broadcasting,reproductiononmicrofilmsorinanyotherphysicalway,andtransmissionor informationstorageandretrieval,electronicadaptation,computersoftware,orbysimilarordissimilarmethodologynowknownorhereafterdeveloped. Theuseofgeneraldescriptivenames,registerednames,trademarks,servicemarks,etc.inthispublicationdoesnotimply,evenintheabsenceofaspecific statement,thatsuchnamesareexemptfromtherelevantprotectivelawsandregulationsandthereforefreeforgeneraluse. Thepublisher,theauthorsandtheeditorsaresafetoassumethattheadviceandinformationinthisbookarebelievedtobetrueandaccurateatthedate ofpublication.Neitherthepublishernortheauthorsortheeditorsgiveawarranty,expressedorimplied,withrespecttothematerialcontainedhereinor foranyerrorsoromissionsthatmayhavebeenmade.Thepublisherremainsneutralwithregardtojurisdictionalclaimsinpublishedmapsandinstitutional affiliations. ThisSpringerimprintispublishedbytheregisteredcompanySpringerNatureSwitzerlandAG Theregisteredcompanyaddressis:Gewerbestrasse11,6330Cham,Switzerland Preface DynamicsofCivilStructuresrepresentsoneofeightvolumesoftechnicalpaperspresentedatthe38thIMAC,AConference andExpositiononStructuralDynamics,organizedbytheSocietyforExperimentalMechanics,andheldinHouston,Texas, February10–13,2020.ThefullproceedingsalsoincludevolumesonNonlinearStructuresandSystems;ModelValidation andUncertaintyQuantification;DynamicSubstructures;SpecialTopicsinStructuralDynamics&ExperimentalTechniques; RotatingMachinery,OpticalMethods&ScanningLDVMethods;SensorsandInstrumentation,Aircraft/Aerospace,Energy Harvesting&DynamicEnvironmentsTesting;andTopicsinModalAnalysis&Testing. Eachcollectionpresentsearlyfindingsfromanalytical,experimental,andcomputationalinvestigationsonanimportant areawithinStructuralDynamics.DynamicsofCivilStructuresisoneoftheseareaswhichcovertopicsofinterestofseveral disciplinesinengineeringandscience. The Dynamics of Civil Structures Technical Division serves as a primary focal point within the SEM umbrella for technicalactivitiesdevotedtocivilstructuresanalysis,testing,monitoring,andassessment.Thisvolumecoversavarietyof topicsincludingstructuralvibrations,damageidentification,human-structureinteraction,vibrationcontrol,modelupdating, modalanalysisofin-servicestructures,innovativemeasurementtechniquesandmobilesensing,andbridgedynamicsamong manyothertopics. Papers cover testing and analysis of different kinds of civil engineering structures such as buildings, bridges, stadiums, dams,andothers. Theorganizerswouldliketothanktheauthors,presenters,sessionorganizers,andsessionchairsfortheirparticipationin thistrack. Bethlehem,PA,USA ShamimPakzad v Contents 1 Graphene-RubberLayeredFunctionalCompositesforSeismicIsolation........................................ 1 MariaRosariaMarsicoandJuliánMauricioLondoñoMonsalve 2 WhatRollercoastersCanTeachUsAboutFatigueLifeofBridgeConnections.................................. 5 SofiaPuertoTchemodanovaandMasoudSanayei 3 UsingResonanceDecayResponsestoModeltheNonlinearBehaviourofTelecomMonopolesVia BackboneCurves........................................................................................................ 15 JoseA.JimenezCapillaandJulianM.LondonoMonsalve 4 TrenchWarfare!TheBattleAgainstGround-borneVibration .................................................... 21 MichaelJ.WesolowskyandMelissaW.Y.Wong 5 Vibration-BasedDamageDetectionUsingInput-OutputandOutput-OnlyEnvironmental Models:AComparison ................................................................................................. 29 PernilleLysgaard,SandroD.R.Amador,SiljaTeaNielsen,EvangelosKatsanos,andRuneBrincker 6 TechniquesforSimulatingFrozenBearingDamageinBridgeStructuresforthePurposeofDrive-by HealthMonitoring....................................................................................................... 39 RobertLocke,LauraRedmond,andSezAtamturktur 7 TheMinimumDetectableDamageasanOptimizationCriterionforPerformance-Based SensorPlacement........................................................................................................ 53 AlexanderMendler,MichaelDöhler,CarlosE.Ventura,andLaurentMevel 8 VibrationsAssessmentofExistingBuildingFoundationsDuetoMovingTrainsinUnderground Tunnels.................................................................................................................... 65 OnurAvci,AshishBhargava,NikolaosNikitas,andDanielJ.Inman 9 Ambient Vibration Tests and Modal Response Analysis of Guayaquil Metropolitan Cathedral inGuayaquil,Ecuador.................................................................................................. 75 M.Motamedi,C. E.Ventura,O.Lara,andJ. H.Barredo 10 An Overview on Floor Vibration Serviceability Evaluation Methods with a Large Database ofRecordedFloorData................................................................................................. 91 MohammadRoyvaran,OnurAvci,andBradDavis 11 ComparativeStudyofFloorServiceabilityMethodologies......................................................... 103 C.Chen,P.Duffour,andA.Margnelli 12 ExperimentalModalAnalysisofDoubleTeeFloorsinaFireDamagedParkingDeckforPost-Fire Vibration-BasedConditionAssessment............................................................................... 113 MatthewWhelan,NicoleBraxtan,GlendaMayo,andBrettTempest 13 OccupantLocalizationinObstructiveIndoorEnvironmentsUsingFootstep-InducedFloorVibrations..... 121 MostafaMirshekari,JonathonFagert,ShijiaPan,PeiZhang,andHaeYoungNoh vii viii Contents 14 Time-Frequency Analysis of Crowd Lateral Dynamic Forcing from Full-Scale Measurements ontheCliftonSuspensionBridge...................................................................................... 125 R.E.White,N.A.Alexander,andJ.H.G.Macdonald 15 ValidationofDeflectionMonitoringforAncillaryTrafficStructuresviaWirelessAccelerometers ........... 135 DelaneyC.Thompson,RodrigoSarlo,andMatthewH.Hebdon 16 LocalizationofStationarySourceofFloorVibrationUsingSteeredResponsePowerMethod ................ 141 MohammadRoyvaran,KevinD.Donohue,andBradDavis 17 PredictionsofFootbridgeVibrationsandInfluencingLoadModelDecisions.................................... 151 LarsPedersenandChristianFrier 18 ADamageDetectionStrategyonBridgeExternalTendonsThroughLong-TimeMonitoring................. 159 AlfredoCigada,FrancescantonioLucà,MarziaMalavisi,andGiuseppeMancini 19 StructuralHealthMonitoringofaDamagedOperatingBridge:ASupervisedLearningCaseStudy ........ 169 A.Cigada,F.Lucà,M.Malavisi,andG.Mancini 20 ComparisonofTime-DomainandTime-Frequency-DomainSystemIdentificationMethodsonTall BuildingDatawithNoise ............................................................................................... 179 RonwaldoE.R.Aquino,MohamedBarbosh,andAyanSadhu 21 FatigueLifeAnalysisofMainShaftBearingsinWindTurbinesUsingStrainMeasurementsCollected onBlades ................................................................................................................. 185 BridgetMoynihan,SauroLiberatore,BabakMoaveni,andUsmanKhan 22 TowardstheDetectionandLocalizationofMultipleOccupantFootstepsfromVibroacoustic Measurements............................................................................................................ 193 Sa’edAlajlouni,MuratAmbarkutuk,andPabloTarazaga 23 AnAugmentedRisk-BasedParadigmforStructuralHealthMonitoring......................................... 201 AidanJ.Hughes,RobertJ.Barthorpe,CharlesR.Farrar,andKeithWorden 24 Running Safety Analysis Considering Track Irregularities on an Open-deck Steel Plate Girder BridgeUsingFiniteElementMultibodyDynamics.................................................................. 213 SanghyunChoi,SoohoChae,KyounghoKim,andIn-ChulBack 25 InfluenceofState-SwitchingRotationalInertiaDampersontheNaturalFrequenciesandResponse ofStructures.............................................................................................................. 217 AbdollahJavidialesaadiandNicholasWierschem 26 TowardsPopulation-BasedStructuralHealthMonitoring,PartVI:StructuresasGeometry ................. 221 KeithWorden 27 ComparisonofModalParametersofaConcreteSlabFloorfromEMAandOMA............................. 237 EllisKessler,VijayaV.N.SriramMalladi,RodrigoSarlo,LukeA.Martin,andPabloA.Tarazaga 28 ModelingHumanJumpingForceonaFlexibleStructureUsingControlModels ............................... 241 AhmedT.AlzubaidiandJuanM.Caicedo 29 ControlofTraffic-InducedGroundVibrationsinaResidentialStructure ....................................... 251 BradPridham,TomNormile,ChristianKronenwetter,PaulReynolds,andEmmaHudson Chapter 1 Graphene-Rubber Layered Functional Composites for Seismic Isolation MariaRosariaMarsicoandJuliánMauricioLondoñoMonsalve Abstract Elastomeric isolators are special devices used for seismic isolation of structures. Typically, they are made of alternate layers of steeland rubber and they positioned between the structure and itsfoundations todecouple them. Novel Graphene-Reinforced Elastomeric Isolators, GREI, are proposed in this study to overcome the heavy weight and long manufacturingprocessofelastomericisolatorscurrentlyused. This manuscript presents an experimental dynamic analysis on rubber pads reinforced with a few layer graphene. Experimental modal analysis is performed on a mass-spring-damper system and the dynamics of the system and the mechanicalpropertiesessentialtocharacterizethespecimensareextractedfromthemeasuredfrequencyresponsefunction. Resultsshowthatafewlayergraphenetransferredonarubberpadincreasestiffnessanddampingofthegraphene-rubber composite; hence natural rubber can be used in lieu of high-damped rubber, saving the cost of reinforcing rubber with particulatefillers.Alsoresultsshowthatthemechanicalpropertiesofthegraphene-rubbercompositealterwhenvaryingthe thicknessofafewlayergraphenetransferredonrubberpads. Keywords Elastomericisolators · Frequencyresponsefunction · Graphene-rubbercomposite · Modalanalysis 1.1 Introduction TheconceptofinterposingElastomericisolators(EIs)betweenastructureanditsfoundationstodecouplethemisknownas baseisolation;itisacceptedbyallmajorinternationalseismiccodesandenablesstructurestosurvivepotentiallydevastating seismic events. Current technologies for base isolation use steel-reinforced elastomeric isolators (SREI) which are made of alternate layers of steel and rubber and are used mainly in strategic and public buildings due to high cost of designing, production and installation. The primary weight in a SREI is due to the reinforcing steel plates which are used to provide the rubber-steel composite with high vertical stiffness, and to the end steel plates at the bottom and top which are used to securethedevicetothestructureandthefoundations.Studieshavebeenconductedtoinvestigatethedynamicbehaviourof isolators reinforced with fibre sheets e.g. glass or carbon fibres (Fibre-Reinforced Elastomeric Isolators, FREI), which are lighterthansteelshims,andwithoutendsteelplates[1–4].However,aspectssuchasthedesign,alignmentandbehaviourof thefibres,thedependenceofFREItopreloadinghistorywouldrequirefurtherinvestigation. Anattractivealternativetousingfibrestoreinforcerubberisgraphene.Graphene,aone-atomthicklayerofcarbon,isthe strongestknownmaterial,whichisalsomechanicallyflexible.Theideabehindthisresearchistoreinforcepurerubberwith afew-layergrapheneandtocreateGraphene-ReinforcedElastomericIsolator(GREI).Thedynamicresponseofsquareand circulargraphene-rubberspecimenswithappliedverticalloadisinvestigatedandexperimentalresultsarediscussed. M.R.Marsico((cid:2))·J.M.LondoñoMonsalve CollegeofEngineering,MathematicsandPhysicalSciences,UniversityofExeter,Exeter,UK e-mail:[email protected] ©TheSocietyforExperimentalMechanics,Inc.2021 1 S.Pakzad(ed.),DynamicsofCivilStructures,Volume2,ConferenceProceedingsoftheSocietyforExperimentalMechanicsSeries, https://doi.org/10.1007/978-3-030-47634-2_1 2 M.R.MarsicoandJ.M.LondoñoMonsalve Fig.1.1 (a)Specimens1.2and1.3madeofasquarerubberpad15mmthick.(b)Circularsample1.5mmthickrubberpadwithafewlayer grapheneontop.(c)Specimen2.2madeofninecircularrubberpadswith1kgappliedverticalload.(d)Specimen2.1madeofninecircularrubber pads.(e)Experimentalsetup 1.2 CompositionofSpecimensand ExperimentalSetup Twosetsofsamples,withcircularandsquaregeometriesweremanufactured.Set1samplesareconfinedtotwo72×72mm squaresteelplates3mmthick,whileSet2samplesareconfinedtotwocircularsteelplates3mmthickwith72mmdiameter. Set1consistsofthreespecimens.Specimen1.1ismadeofasquarepurerubberpad47mmsideand15mmthick;Specimen 1.2 is made of a square rubber pad 47 mm side and 15 mm thick with a circular thick layer of graphene on the top with diameter of 38 mm; and Specimen 1.3 is made of a square rubber pad 47 mm side and 15 mm thick with a circular thin layerofgrapheneonthetopwithdiameterof38mm(Fig.1.1a).Set2consistsoftwospecimensmadewithninecircular padsofrubbereachwithdiameter47mmandthickness1.5mm.Specimen2.1ismadeofninepadsofpurerubberbonded togetherusingacoldvulcanizingagent.Specimen2.2ismadeofninepadsofrubberalternatedtoeightcircularthinlayers ofgraphenewithdiameter38mm(Fig.1.1b–d). Graphene deposition on rubber was achieved by an isopropyl alcohol assisted direct transfer method [5]. To vary the thicknessofthegraphenefilmsonrubber,multipletransfersofgraphenefilmswereused(i.e.3transfersforthethinfilms ◦ and6transfersforthethickfilms).Theelastomerusedinthesamplesisnaturalrubberwithhardness70 ShoreADegree, measuredexperimentallyusingaRSProdigitaldurometer. TheexperimentalsetupshowninFig.1.1ecanbeseenasasingle-degree-of-freedom(SDOF)mass-spring-dampersystem withaccelerationsrecordedatthebottomofthelowersteelplatebondedtothespecimenandatthetopoftheaddedmass. Experimental modal analysis was performed and the dynamics of the system and the mechanical properties essential to characterizethespecimenswereextractedfromthemeasuredFrequencyResponseFunction(FRF). Gravityloadsareappliedonthespecimensintheformofasolidstainlesssteelcylinderboltedontheuppersteelplate (1 kg and 2 kg at a time). Vibration tests were also performed on one of the 3 mm steel plate alone to define its natural frequencyandultimatelytoassessanydynamicinteractionwiththedynamicbehaviourofthegraphene-rubbercompound. 1.3 Analysis FRFsofSet1sampleswereusedtoevaluatethespecimens’mechanicalbehaviourandtoextractdynamicpropertiessuch asnaturalfrequencyanddamping.FRFsshowthattheverticalnaturalfrequencyofthetwospecimens1.2and1.3madeof arubberpadandlayersofgrapheneontop(eitherthinorthick)ishigherthanthenaturalfrequencyofthespecimenmade of pure rubber (specimen 1.1). This result proves that specimens 1.2 and 1.3 are stiffer vertically than specimen 1.1, and thattheincreaseinverticalstiffnessisduelikelytotheaddedlayersofgraphene.Theverticalnaturalfrequencyofthethree specimensisplottedinFig.1.2a,alsoshowingthatforexcitingfrequencieslessthan250Hz(i.e.afrequencyratiolessthan 0.7)thedynamicresponseofthespecimensisdisturbedbythedynamicresponseoftheconfiningsteelplates.