Biomechanics of Occupant Ejection During Rollover Accidents

the.uAorticValve edical Engineering expertsin this field "sion in the field of ry yet the evolution rer is to exPloretne rt, it can function :e at the very fint m the valve sParing e dimensionsof the ltt€tnptto develoPa sparingsurgery.It :n betterresultsand ng physicians and rgineeringscientists rtion, Biomaterials, , Medical lrnaging, I Deviceslndusties 1S. 22ndSouthernBiomedicalEngineering Conference and Symposiumon Aortic ValveSparing Surgery ConferenceChairman ManoJ. Thubrikar, PhD,FAHA. Heineman MedicalResearchLaboratories Carolinas MedicalCenter NC Charlotte, Gonference Co-Ghairs Francis Robicsek, MD,PhD. TheCarolinas Heartlnstituteand TheSangerClinic Charlotte. NC Subrata Saha,PhD. AlfredUniversity, NY BIOMEGHANICS OFOCCUPANT EJECTION DURING ROLLOVER ACCIDENTS AnthonySances,Jr.,Srirangam Kumaresan, FredCarlin University Of California, SantaBarbara, CA Biomechanics lnstitute, SantaBarbara, CA Themostdangerous crashesmeasured by the highestfatarityor seriousinjuriesto numberof occupants in tigntvlhiclesJr"in" rolloveraccidents.significanflymore fatilities and *"iiou" injuriesoccurdue to electionin roll overaccidents. The fresint studywas conductedto deter.mine the occupantretentionand hg3d-nec.tr injurypotentiaraipectsof raminated grassin nxeo sidewindow,side doorwindowsand sunroofsoriringroil over a_ccidents. The test protocolforthisstudywasbasedo-nNationat HighwayTraffic safety Administration (NHTSA)stuoiestor advancedglazing.The impactstudyof ia kg with head-neck form was conducted on laminatedglass from proOu.tion Th-edrop speedwasvariedfrom 11 to 16 kpn.ihe ygliglg_..: Hybridlll 50%maledummyhead-neck formwasinipacted in the approximate centerof theglassportionof thewindowb. A totalof 20 testswereconducted. A seriesof droptestswereconducted on sidewindowswith laminated glass,fixedsidewindowsand sunroofwindows.The head'injury criteria,head resultant acceleration, and neckloadsand momentswerequantified. A comparison was rnade betweenvarioustypes of laminated glass.In all cases,the head-neck biomechanicar parameters werewellbelowthe criticalvalueinjurytolerance liniitsandthe glasscoritainedthe dummy.The presentstudydemonstrates that.he.ad-neck injuryis unlikelydue to laminated glassusedin production vehiclesduringrollover accidents. Presentedat Southem Biomedical Aortic Valve SparingSurgery.,Septernber2003 BIOMECHANICSOF OCCUPANTEJECTION DURINGROLLOVER ACCIDENTS Anthony SancesnJr., Srirlngam Kumaresan, Fred Carlin, Keith Friedman +, Steve Meyer * University of California, SantaBarbara,CA BiornechanicsInstitute, SantaBartara, CA + FriedmanResearch,Goleta,CA * SAFE.Goleta.CA INTRODUCTION A major crash modality rezulting in occupant ejection is rollover. Rollover accidents are most the dangerouscrashes measuredby the highest fatality or serious injuries to number of occupantsin lighr vehicles [l]. Malliaris reported that rollovers accountedfor over 50% of ejection and over 55oloof the harm to ejectees,althoughit rcpresentedonly about 8% of the crashmodes[2]. Summersindicated that the urajority of the roll over fatalities come from l0% of the roll over involved occupaf,tswho are ejected, or partially ejected,from the vehicle [3]. Terhunealso found ejection rat€s were substantially higher in roll over than in non-roll over crashes[4]. Clark found that almosta third of the occupantsin crasheswith roll over and ejection urill have serious or greater injuries [5]. A roll over study by Orlowski indicated that it is generally more desirableto remain in the car than to be ejectedin a roll over collision [6]. The ejection during rollovers is more seriousfor light trucks and vans(LTVs) than for passengercars [7]. Terhuneconcludedthal light trucks differed from passengercars ia more frequentlyexposingtheir occupantsto risk throughsingle vehicle rollovers andnoted that the rollover tendencieswere most pronouncodin LTVs [4]. Winniki reportedan analysisby vehicle type and showedbenefitsof ejection prevention in light rucks. For drivers of light trucl$ in ejection crashesthe relative risk of fatality was 5.62 and for passengersit was 4.66 (comparedwith the non-ejectedoccupant).The fractional reduction in fatalitieswas estimatedas 82 percentfor drivers and 78.5 percentfor passengerswhen ejection was eliminatedfrom thesevehicles[8]. By reducing the opportunity for ejection ttreprobability of severcinjury or fatality associatedwith ejection would be correspondinglyreduced. Therefore,the purpose of this study is to examinethe occupantretentioncapability and head-neckinjury aspectsof laminatedglassin side windows andsunroofin vehicles. The presentstudy is a continuationof our previoussnrdieson laminatedglass[9-12]. METHODS The test protocols for this study were basedon recentNational Highuay Traffic SafetyAdministration(NHTSA) studiesfor advancedglazing [3]. The retention study utilized an l8 kg weight with an averageglass contactspeedof ll kph. A Hybrid III 507omale dummy head was instrumentedwith Endevco 72648-2000or ?231C-750TStri-axial accelerometers and filtered at Class 1000 SAE. Occipital condyle (upper neck) transducersmeasuredneck forces and moments.All data were sampledat l2.5kHz. The fiead and neck were assembledto the upper torso of a H),trid III 50% male surrogate.The armswere removedand weight of the assemblyadjustedto 18 kg. The durnmywas allowed to free-fall from a height of 0.5 m to 1.0 m onto clips from 1970 to 1989 light truck and van laminatedside and door windows. The clips consistedof the glass, the glass mounting, and dre surrounding support structure. The duurmy was dropped laterally at an angle of approximately26 degreesso that the headhit first on the interior portion of eachclip. For the Volvo tes! the durrxny was dropped laterally at an angle of approximately42 degreesdue to narrow door. However, the neck moment values were recalculatedto incorporatethe difrerencein angle. The dumrnywas impactedlalerally to simulatethe roll over behavior of occupa4ts.The drop heightsusedresultedin impactsof I I to 16 kph (7 to 10mph). RESULTSAI\D DISCUSSION In all tests,the laminatedglass fracturedand deformed. The glass retainedthe dummyassemble.The headand neck injury parameterswere below the tolerancevalues(Table l). The 36 ms headinjury oriteria (HIC) valuesare less than 600. The test protocols for this study were basedon recent National Highway Traffrc Safety Administration (M{TSA) studies for advancedglazing. The retention study utilized an 18 kg weight with an averageglasscontactspeedof I I kph. The dummy was dropped laterally at an angle of approximately26 to 28 degreesso that ttreheadhit first on the interior portion of each clip. The dummywas impacted laterally to simulatethe roll over behaviorof ocoupants.Rezultsindicated that the fractwed glass oontainedthe dummy assembly and the head-neckbiomechanicalparameterswere below the critical value injury that head-neckinjury is unlikely due to tolerancelimits in simulated rollover accidents. The present study demonstrates laminatedglasscontactusedin produclion vehiclesduring rollover impacts. Table 1: Peak biomechanicalhead nnd neck Test I z 3 4 5 6 8 9 l0 II 12 13 t4 l5 l6 t'7 l8 t9 20 tr'lexion Extension Lateral Details My Bending Mx N-m N-m N-m 36 ms kph 11 . 5 9:1 1.9 NA+ 89 Suburbau 11.4 r0.6 4.8 l t.4 47.5 NA* 75-79ChevBlazerK5 I1.4 49.3 t2.6 2.3 NAI 89 Suburban )) 8.4 NA+ FordE-150 I1.4 24.7 4.1 I1.4 l9 1.6 NA* Ford Van 5.5 17.276 Ford Club Wason 11.4 18.2 4.1 2.7 I1.4 26 8.5 14.379 Ford Club Waeon 3.t 16.1 30.3 10.3 1 5 . 576 Ford Club Waeon 10.6 14.677FordE-150 l6.l l8 16.1 461 7.8 9.6 29.978 FordE-150 5.8 I 1.3 15.8 13.6 23.81984Chew Suburban 3.9 18.1 3 3 . 11983Chew Suburban. t 6 .r 588 11.3 6.8 8.6 30.61983Chew Suburban t7.7 983 l r .3 24.4 4.8 17.3 27.3HondaPrelude1979-1 Tovota Forerurmer1994 I 1.3 I 1.3 17.4 13.0 27.0ToyotaForerunner1994 I 1.3 90 5.8 17.3 4 1 . 0NissanMaxima1992 l 1.3 29.4 4.6 8.5 2 7 . 1Nissan2802 1983 IJ. I 16,1 258 t6.l 1983 66.5Nissan-280-Z 11.4 77.5 6.4 2.0 40.2Volvo 80 series1999 Impact HIC Location Reardoor fixed fixed sidewindow fxed sidewindow side carso door fixed fixed sidewindow fixed side window fixed sidewindow fixed side window fixed sidewindow fixed sidewindow l-eft rear door window Right rear door window l,eft rear door window Sunroof Sumoof Sunroof Sunroof T-top T-top Rieht front door +Sensorbottomedout, No data Reference: 2001. FederalRegbterOct 22, 2(Ml,vol.66, pp. 533?6-53385, Rogister,F, 'FcderalMotor VehicleSafetyStandalds;RoofCrushResistanse," ltI pl Malliaris, AC, Dgblois, JH and Digges,KH, "Ught Vehicle Occupant Ejectiom - A Comprh€nsive Investigation," lccident Ana$nis ond 13l t4l ts1 t61 17l t81 tel ll0l Il] t l2l ll3l Preventinn,vol. 28, pp. l -14, 1996. Summers,S, Rains,GC and Wilke W,"Currcnt ResearchIn Rollover and OccupantRelention:' lsth lnll Tech Conf oa .thc EnhancedSafetyof Vehicles,l996. Terhung KW,'i4 Comryrison Of Lighl TruckAnd PassengerCar OccupqntProaction In Single-VehicleCrashesl' Awin/Calspan Franklin Research 19861986. Center,Buffalo,N.Y. 14225CalspenReportNo. 7438-1,September Clark, CC, Yudenfrien4 H and Redner, AS,"Laceration And EjecaionDoryers Of Aulonotive Glass,And The WeakStandardsInvolved. The StrainFrdcturelest ," 44th Annual.Proceedings AssociationForThe AdvancenentOf AutomotiveMedicine,pp. ll7-131.2000. Orlowski, KF, Bundorf, RT and Moffatt, EA,"Rollover Crash TesE-The Infuence Of Roofslrenglh On Injury Mechanics,"29th Sapp Car CmshConference,l 985. Clark CC and Sursi, P, "Rollover Crash ard LabomtoryT€stsof EjoorionReductionBy Glass-PlasticSide Windows and Windshields," Societv ofAutomotive Engineers,400 ComrmnwealthDrive, Warrendale,P,{ /J096, vol. SAE Paper890218, 1989. Winniki, J, "Er,inro ting the Injury-Reducing EeneJiEof Ejection-Mitigatlng Glaziag,"NHTSA DOT HS 808 369., February, 1996, 1996. Sanc€s,A, Jr., Carfin, F and Kumaresan,S,"Eionechanical Analysisd Headand Necklnjw with Roll Over GlassImpacts," ASME 2001 SummerAdvancesin Bioengineering,Z00l. Sances,AJ, Carlin, FH and Kumaresan,S, "Biomechanicallnjury Evaluationof taminatedClassDuring RolloverC,onditions,"SAE Paper 20020l-1,146,p. l -5,2002. Sances,d Jr., Kumaresan,S and Carlin, F, "SancesA Jr Carlin FH, KumaresanS, Enz B: Biomedical EngineeringanalysisofGlass Impact Injuries.," Critr'cal Reviewsin Biomedical Engineeing, vol.30 (4{), pp. 345-317,2002. Sances,A, Kumaresaq S, Carlin, F, Fri€dman,K and Meyer, S, "Biomechanicallnjury Evaluationof l-aminatedSide Door Windows and SunroofDuring Rollover Acciden6.," LS,{,vol. Vol 437, pp. 241-244,2W3. Willke, D, Summers,S, Wang, J, lre, J, Partyka,S, and Duf$', S, *E?crron MitiEation UsingAdvancedGlazing: StatusReport II:' National Highnay SafetyTraffic Administration August 1999.