BIOKINETIC LIMITS IN AUTOMOT IVE ENGINEERING. L Sol berg Larsen and A Aasberg AB Volvo, Gothenburg, Sweden

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1 BOKC S UOO by Sol berg aren and aberg B olvo, othenburg, Sweden ntrodution hi aer wa hoen to form a link between the ientifi eion at Chalmer Univerity of ehnology and the viit to olvo in onluion of the 979 COB nternational Conferene. On thi oaion, therefore, we woul d like to reent a brief ummary within the COB area of ma in interet in relation to olvo ' reearh ativitie, whih are bei ng made in reone to oml iane with future legal requi rement laed by government on automotive engi neering. Suh reone i hown a a ytem aroah in Figure. COB ' area of greatet onern in thi ytem aroah overview would lie within Crahworthine Sytem and the two ubytem of Ouant Comartment and ehile Crah nergy anagement. olvo ' utomotive Safety Hitory uring the 94', olvo deided to deign and rodue it aenger ar baed on the monooque theory of truture, whih mean that the automobile body i elfuorting and require no extra frame for engine and hai uenion. hi romoted extenive knowl edge with regard to heet metal trutural engineering, whih wa eential for body rahworthine develoment (). bout ten year later, ol vo ma de another imortant afety deiion: to introdue eat belt a tandard equiment in al l ar wherever olvo were old. hee two deiion, we bel ieve, laid a ol id foundation for olvo' ubequent endeavor in automotive afety. ogether with the deiion to ondut mul tidiil inary aident invetigation on a ontinuou bai, with raid feedbak to deign, engi neering and rodution, they have formed a oniderable afety engineering exeriene whih i now art of olvo ' emiriim (2,3,4). Biokinet i Conideration in olvo ngi neering Before the early 97', biokineti limit had only an indiret bearing uon motor vehile deign and engineering. Seat belt and other rotetive meaure were hardly ever evaluated a art of an overal l, vehiledeigned, rahworthine ytem. ntead, omonent of the variou afety ytem were teted a iolated item. or wa the integration of the retraintrah rotetive ytem into the vehile rahworthine ytem meaured in a quantitative manner whih ould be related to injuryreduing otential of the omlete deign akage. 328

2 One obviou reaon for thi hortoming wa lak of tehnology to erform uh tet in a meaningful way. Ba ial ly there were no anthroomorhi dummie whih ould imul ate ouant kinemati during a rah with uffiient onfidene. he other rna in reaon rel ate loely to the immediate objetive of the COB onferene and enter around the arameter to be meaured in or on the durnmie during tet for a onfident afety evaluation. he iene of biomehani ha made fruitful rogre during reent year with regard to uh teting, eeially regard ing frontal rah evaluation. oday we have available at leat ome develoed dummie whih we bel ieve an give u rea onable tet value when we want to onare different olution for ouant rotetion in frontal rahe. Of oure, dummie mut be further devel oed to atify new demand emerging from extended knowl edge in the field of biomehani, a ha been dernontrated during thi onferene. hi i al o reognized in the rulema king and tandardetting roe (5,6) whih i hown at the end of the aer. eent Biokineti imit in Crahworthine eearh eite the lak of wel l defined biokineti limit in mot automotive afety area, ertinent inj ury riteria have been al ied to rahworthine rati ng of vehile and retra int ytem in a number of ar rah afety rogram. he mot extenive of thee endeavor i the xerimental Safety ehile (S ) rogram, in wh ih all the major automobile roduer of the world are artiiating. n addition to thi international rogram, the US government ha uorted a number of na tiona l ar rah afety develomental rogram, uh a the one for reearh afety vehile, and eval uation rojet for variou retra int ytem integrated in both ordi nary rodution vehile and in lightly truturally mod ified one. For one of thee develomental roj et, deigned to etabl ih uitable future rahworthine goal for rodution vehile, the olvo 24 wa hoen a a reearh latform, or bael ine, for evaluation of advaned retra int ytem baed on develoed 3oint eat belt tehnology and advaned inflatable (air bag) retraint. n thi rojet, injury riteria were evaluated from dummy meaurement in order to ma the erformane of different retraint ytem under a variety of rah ondition of the frontal imat tye. hu the rojet inluded fixedbarrier and vehiletovehile imat. n the latter rah tet, olvo were imated againt other olvo in full frontal engagement and in offet imat oition. dditionally, ful l ized US automobile were taged to ollide with ol vo in headon, offet and frontal obl ique imat oition. uri ng thi extenive rah teting it wa etabl i hed that the limiting biokineti riteria were the ehet aeleration for alrnot all imat mode. For the forelimited bel t retraint ytem, however, during headon imat ondition, the reent head injury riteria were hown to be the ritial one. ( hort film of thi reearh hown here.) 329

3 From thee rah tet the HS onl uded that frontal rah rotetion within biokineti limit ould be ahieved u to rah veloity hange of 455 mh with advaned (air bag) retra int ytem (5). t mut be borne in mind, however, that thee reult were obtai ned in an automobi le roviding a large ditane of trutural ol l ae and with a rathe r low average deel eration during the veloity hange. t a 4 mh fixedbarrier imat, for examle, a dynami trutural ol l ae of 384 inhe ould be util ized. Furthermore, rah teting with other ar having a imi lar aaity of trutural ol lae in the frontal imat mode (e.g. the iniar eearh Safety ehile) howed that ouant injury riteria ould be ket within reent biokineti limit u to rah veloity hange omewhat exeed ing 5 mh. ook into the Future he downizing of large, reouredemanding vehile for eronal tranortation wa foreat many year ago by everal author, inluding the reent one ( 7,8). n eferene 8 it wa redited that the tranition to maller, or omat, automobile need not reult in an inreae in ouant fatalitie, if enible rahworthine tehnologie are ued. We bel ieve that thi redition till i val id. ow the ruial quetion i: oe thi mean that vehiletovehile rah goal of 5 mh ould be met in future, downized rodution vehile? We bel ieve that uh goal hould not be attemted without areful onideration of the injury riteria and their rel ation to the biokineti limit. he reaon for thi aution i, of oure, the downizing effort due to fuel eonomy gain hene the maller ditane for trutural ol lae and the leer weight of future vehile mut be taken into onideration. For the ake of omatibil ity wi th the reent vehile oulation, the mal ler and lighter ar of the future hould be made with a high trutural tiffne in order to ma intain the integrity of the ouant omartment whih i eential for a ueful erformane of the retraint ytem. hi wi ll ra ie the average rah deel eration level of the maller future automobile a omared to reent deign level. hi further mean that the reent injury riteria limit wi ll beome ritial at a lower tet veloity. f, on the other hand, it i eential to be below ertain limit for a given tet veloity, for examle due to legal requirement, there would be a more diffiult deign ta k to be erformed a the vehile are getting maller. lt wi ll alo be neeary to ue the biokineti limit wi th lower margin when deigning the retra int ytem for ue in maller vehile than when ued in a larger vehile. herefore, the reure for wel l founded and aetable limit wi ll inreae, and the imortane of biokineti limit reearh wi ll obviouly alo inreae during the year ahead. 33

4 Higher egal equirement on the Horizon So far, the US lead in al iation of biokineti limit to deign goal of automotive engi neeri ng ha not been fol lowed by other arroduing ountrie. Conequently, the autornotive indutry ha to omly with everal different requirernent to reah the etabl ihed afety goal. From the automot ive engineering o int of view, therefore, it i al o eential that knowl edge of biokineti limit hould be inrea ed, o that the al iation of uh knowl edge to vehile afety deign an be made in a uniform and onfident manner on a wo rldwide bai. uring the Seventh nternational ehnial Conferene on xerimental Safety ehile, held in Pari in June 979, it beame aarent that many of the COB area of onern will beome ubjet of new and ugraded rulemaking. n the 979 S diuion area of vehile rahworthine, namely: ) frontal rah rotetion and aive retra int develoment, 2) biomehani and dummy develoment, 3) ide imat rotet ion, 4) aident invetigation and data analyi and 5) edetrian rotetion, about a dozen aer attributed to the HS dealt with rah injury, dummy develoment, vehile downizing and the rooed ugrading of the rahworthine tandard. he ma in area of biokinet i devel oment, a een from an automotive indutry oint of view, i rel ated to the evaluation of ytem deigned to rotet vehile ouant during ide imat ondition. Here we have a number of robl em. Firt of al l, the kinema ti of the dummie ued today do not eem to reemble the kinemati of a human being in a imi lar rah envi ronment. Seondly, the arameter ued for evaluation are not at al l a lear a for the frontal imat mode. hirdly, ide imat biokineti limit data are till very rare in the literature. eommendation for biokineti limit in thi rah ituation mut be a highriority item during the year to ome, o a to make it oible to develo the ar in a rational and otbenefiial manner for injury redution. he 979 nternational ehnial Conferene on xerimental Safety eh il gave ome indiation of the road to be attemted (9,). he next biokineti area of onern to the automotive deigner i the evaluation of vehile in regard to rotetion of hildren in different rah mode. l o, in thi area we have a twofold robl em with reet to ytem afety evaluation. One onern the kinemati of the hild dummi e, and the other whih a rameter to elet for a quantitative judgment of a given rotetive ytem. egarding hild tolerane data, our knowl edge today i very are in the frontal a wel l a in the lateral bodyloading ondition. One area of eial onern i related to the future ue of variou aive retraint ytem whih are mainly deigned to tranfer aetable biokineti load to grownu ouant. hi inongruene may reate unwanted load onfiguration, for intane from an automati (aive) belt ytem, a wel l a unaetable load level from an inflating airbag ytem. oday we lak onfident reommendation from the ientifi omrnunity for both of thee ondition in regard to biokineti limit. nother area of onern to the automotive deigner, from the biokineti oint of view, i edetrian rotetion (,2). vjhile oibly the fuel eonomy 33

5 need have reated front and bonnet deign with rounded orner whih might redue the injuryroduing otential in many edetrian imat, we have no good tet today by whih we an omare different bumer deign. Hoeful ly, ome guidel ine wi ll evolve from the reearh whih ha been reented during thi onferene. Conluding _ rema rk he diuion above have attemted to exl ain our onern regarding biokineti limit in relation to our work on vehile deign, and to exre the imortane we ee in the COB onferene. We hoe that we have ueeded in onveying to you our thought and idea, and we now want to wel ome you to olvo' failitie. 32

6 iterature l. knor : Ka ro kontrukt ion (utomobi le body engi neering). e ign rule for body trength and t iffne of ol vo automobi le. (n Swedih). B olvo, othenburg. ev ied Bohl in, orin H and nderon a : tatitial traffi aident analyi with referene to ouant retraint value and rahworthine of the olvo xerimental Safety Car (SC). Fourth nternational ehnial Conferene on xerimental Safety ehile. Kyo to utafon, Sol berg aren and Jakh F: olvo ' afety ytem integration in rodution automobi le: Cra hworthine engi neeri ng. Sixteenth nternational utomobi le ehnial Congre (FS). okyo a berg, Sol berg aren and unberger S: From exerimenta l to rodution afety vehile. Sixth nternationa l e hnial Conferene on xerimental Safety ehile. Wa hi ngton Boehly W, elarm and orri J B: Ugraded frontal rah rotetion for motor vehile ouant. Seventh nternational ehnial Conferene on xerimental Safety ehile. Pari Baka iti S and Haffner : evel oment of the HS advaned dummy for the ouant rotetion tandard ugrade. Seventh nternational ehnial Conferene on xerimental Safety ehil e. Pari Sol berg aren : Prototye and rodution analye for oml iane with governmenta l requirement in automot ive afety. hird uroean Seminar for Qual ity Control in the utomot ive ndutry. Pari aberg, e llde and Bengton S W: he ae for the 3l b ar. hird nternational Congre on utomotive Safety. San Franio Burgett and Hakney J : Sta tu of the ational Highway raffi Safety dmi nitration' reearh and rul ema king ativitie for ugrading ide ima t rotetion. Seventh nternational ehnial Conferene on xerimental Safety ehile. Pari inger H: Coniderat ion in ide imat dummy devel oment. Seventh nternational ehnial Conferene on xerimenta l Safety ehile. Pari inger H and Pritz H ß: evel oment of a iml i fied vehile erformane requirement for edetrian injury mitigation. Seventh nternational ehnial Conferene on xerimental Safety ehile. Pari aniel S, inger H and Cohen : Conideration in the develoment of a edetrian afety tandard. Seventh nternational e hn ial Conferene on xerimental Safety ehile. Pari

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