Aircraft-impact-analysis-of-nuclear-safety-related-concrete-structures-A-review

飞机碰撞

Review

Aircraftimpactanalysisofnuclearsafety-relatedconcrete

structures:A

review

HuaJiang ,MiG.Chorzepa

CollegeofEngineering,TheUniversityofGeorgia,Athens,GA,USA

articleinfoabstract

Safety-relatednuclearstructures,includingconcretenuclearcontainmentvessels,

constructedbeforeSeptember11,2001,werenotpurposelydesignedtoresistanyimpact

loadinggreaterthanalightaircraftcrash.Since2001,safetyofnuclearfacilitiesagainsta

deliberateoraccidentallargecivilianaircraftimpacthasdrawnmuchattentionworldwide.

However,currentdesignguidesfornuclearstructuresprovidelimitedinformationon

analysismethodologiesforsuchaircraftimpact.Thisdocumentpresentsbasicgeneral

knowledgerequiredtoanalyzeconcretestructuresforanaircraftimpactandprovidesa

summaryofavailablenumericalandexperimentalinvestigationsthatmaybeusedto

benchmarkanaircraftimpactsimulation.Themethodologiesavailableforanaircraft

impactanalysisareoverviewedwithanemphasisonstructuraldamageanalysis.Constitu-

tivemodelsusedforconcrete,reinforcingsteel,andcompositematerialsareaddressedin

thispaper.

Ó2014ElsevierLtd.Allrightsreserved.Articlehistory:Received20March2014Receivedinrevisedform19June2014Accepted18August2014Availableonline26August2014Keywords:ConcretestructuresContainmentstructuresAircraftimpactanalysisNuclearPowerPlantRieramethodology

1.Introduction

Sincethemiddleofthe20thcentury,nuclearpowerhasbeenoneofthekeydevelopmentareasforenergygenerationand

isconsideredtoprovideoneofthemostpromisingstrategiesforreducingcarbonemissionsaroundtheworld.Asof2013,

thereare437NuclearPowerPlant(NPP)unitsin31countriesinoperation,and68plantsin15countriesunderconstruction

[1].Despiteofthenuclearproliferation,theriskofunforeseenbeyond-design-basiseventshasbecomeamajorconcernfor

NPPoperatorsandregulatorsaroundtheworldsincetheFukushimaaccidentin2011.Itisnotedthatnuclearsafety-related

concretestructures(CS)includecontainmentbuildings,shieldstructures/building,reactorbuildings,andotherstructures

withsimilarfunctionsinthispaper.

IntheUnitedStates,oldCSconstructedbeforeSeptember11,2001,wasnotpurposelydesignedtoresistanyimpactload-

inggreaterthanalightaircraftcrashwhichwastheaccepteddesign-basiscasedrawnfromtheimprobabilityorpurechance

ofacivilairlineraccidentallycrashingintoaNPP[2].Accidentallargeaircraftimpactisabeyond-design-basisevent,which

requiresriskevaluationusingprobabilisticassessmentmethodsasgiveninDOEStandard[3].SincethetragicSeptember11

incident,safetyofCSagainstadeliberateoraccidentallargecivilianaircraftimpacthasdrawnmuchattentionworldwide.

Abbreviations:NPP,NuclearPowerPlant;CS,concretestructures;DOE,departmentofenergy;NEI,NuclearEnergyInstitute;IAEA,InternationalAtomic

EnergyAgency;NRC,NuclearRegulatoryCommission;AIA,aircraftimpactanalysis;ACI,AmericanConcreteInstitute;ASME,AmericanSocietyof

MechanicalEngineers;ASCE,AmericanSocietyofCivilEngineers;DEM,discreteelementmethod;SPH,theSmoothParticleHydrodynamicMethod;FE,

FiniteElement;FD,FiniteDifference;DIF,DynamicIncreaseFactors. Correspondingauthor.

E-mailaddresses:huajiang2006@http://wendang.chazidian.com(H.Jiang),chorzepa@uga.edu(M.G.Chorzepa).

http://wendang.chazidian.com/10.1016/j.engfailanal.2014.08.008

1350-6307/Ó2014ElsevierLtd.Allrightsreserved.

飞机碰撞

H.Jiang,M.G.Chorzepa/EngineeringFailureAnalysis46(2014)118–133119

However,currentdesignguidesonnuclearsafety-relatedstructures[3–7]providelimitedinformationonanalysismeth-

odologiesforsuchaircraftimpact.DespitethefactthattheNEIguide[8]providesgeneralinformationonthistopic(i.e.reg-

ulatoryrequirementsforbeyonddesignbasis),itdoesnotincludedetailedanalysisproceduresandmaterialmodelsthat

characterizestructuraldamage.ManynumericalstudiesandinvestigationsonaircraftimpactofCShavebeenconducted

sofar;however,numericalmethodsemployedforanimpactanalysisvaryfromsimpletocomplex.Itisdif cultforanana-

lysttomakeadecisionintermsofanalysismethodologies,analysisprograms,constitutivemodels,andelementserosion

criteria.Therefore,thispapergivesanoverviewofaircraftimpactanalysis(AIA)methodologiesandresearch ndingsinthis

regard,includingbothexperimentalandnumericalevaluations.AtabularoverviewofAIApublicationswithdetailedinfor-

mationonthehydrocodes,modelingmethods,materialmodels,andfailuremodesofCSisalsoprovided.Besides,character-

istics,advantages,anddisadvantagesofdifferentAIAmethodologiesaresummarized.Thediscussionshereinarelimitedto

NPPouterCS,designedtohouseareactorandprimarysystemcomponents.Methodologiesemployedforprobabilityrisk-

basedassessmentsand reorexplosioneffectsinitiatedbyaircraftfuelarenotincludedinthispaper.

2.Basicgeneralknowledge

Generalknowledgeofthefollowingmethodologyandclassi cationsiscriticalinordertounderstandorperformanAIAof

CS.

2.1.TheRieramethodology

Riera[9]developedasimpleanalyticalformulatoapproximatetheload–timefunctionofanaircraftnormalimpact

againstarigidsurfacebasedonthemass,stiffnessdistributionandbucklingloadoftheaircraft.TheRiera’sformulahas

servedasabasisfortheforce–timehistoryanalysispresentedinSection4.1.ThismethodisincludedintheNEIreport

[8],andisadoptedintheDOEstandard[3]andothertechnicaldocuments[7].However,Abbasetal.[10]pointedoutthat

theRieraformulaisbasedonthegradualcrushingoftheprojectile,whichisnotrealisticandcangivemuchconservative

result.Theyproposedanapproachforcalculatingimpactforceonthebasisofconservationofmass,momentumandenergy

togetherwiththeconsiderationofcertainmodeofcollapse,andhighlightedtheerrorintheevaluationofreactiontime

responseusingtheconventionalapproachbyconsideringtheimpactofahollowcylindricalmissile.

2.2.Hardimpactversussoftimpact

Theretwocategoriesofstructuralimpact:softmissileimpact(impulsiveloading,impulsedriven)andhardmissile

impact(impactiveloading,energydriven).Twomethodshavebeenprimarilyproposedtoclassifysoftandhardimpacts:

2.2.1.MethodI

Eibl[11]classi estheimpactashardorsoftbasedonwhetherthemissiledeformabilityissmallorlargerrelativetothe

targetdeformabilityusingamass-springmodel(Fig.1a).Inthis gure,thespring,k1,representstheforceresultingfromthe

contactbetweenprojectile,m1,andtarget,m2.Thespring,k2,representstheresistingforceoftargetduetothedeformation

inthetarget.Twoequilibriumequationscanbewrittenasfollows,wherex1(t)andx2(t)denotedisplacementinthe

projectileandtarget,

respectively.