Research On The Protective Effect Of Different Seatbelt Pretensioning Methods On Occupant On The Frontal Collision

Seatbe lt is the most e ffective occupant protection device,wearing seatbelt correctly can effect ive ly reduce the occupant casua lt y rate in a collis ion accident.Nowadays w idely used pyrotechnica l pretens ion seatbelts are deve loped and designed for 50^{t h} nor ma l sitt ing ma le occupants,whe n the co llis ion happens,fir ing pyrotechnical,t ight ing webbing seatbelt rap idly,protecting the occupants.However,wit h the increase of car occupants,the occupant s inc lude not only the 50^{t h} percent ile ma le occupants,and the exist ing seatbelt syste m does not necessarily ha ve a good protective effect for other body size occupants;moreover,w ith t he deve lopme nt of the vehic le active safety techno logy,more and more vehic les are equipped with the Autono mous Emer genc y Braking System?A EB?t hat causes the occupants no lo nger in the init ia l sitt ing posit io n when a collis io n happens.The literature stud ies show that the occupants out of the init ia l sitt ing posit io n w ill affect the protective effect of the pyrotechnical pretens ion seatbelt.In view o f the above sit uat ion,this paper designe s a reversib le pretens ion seatbelt device which funct ions in the pre-crash and studies the protective effect of different seatbelt pretens ioning met hods on the occupants of different body size in t he fronta l collis ion cond it io ns inc luding the aeb in the pre-crash stage.The specific research work is as follows:1.Designing and making an active pretens ion seatbelt device,us ing the device to do the reliabili ty test,out of occupant correcting test,working noise test.2.Based on the software MADYMO,establis hing and verifying a fro ntal impact restraint s ystem s imulat ion mode l,on the basic o f whic h,adding a pre-crash inc lud ing aeb and five different seatbelt pretensioning met hods inc luding retract or pyrotechnical pretens ion,buckle pyrotechnical pretens ion,retractor reversib le pretens ion,retractor revers ible pretens ion co mbined w it h retractor pyrotechnica l pretens ion,retractor revers ible pretens ion comb ined with buck le pyrotechnica l pretension.3.Based on the act ive human model of MADYMO,studying the influe nce of aeb in the pre-crash and five d iffere nt seatbe lt pretensio ning met hods to the mot ion response in t he pre-crash,inj ury index in t he collis ion a nd the overall protect ive effect of 50^{t h} percent male occupants.4.Based on the 5^{t h} percent ile fema le huma n body model,95^{t h} percent ile ma le huma n body model,st udying t he protect ive e ffect of the five different d ifferent seatbelt pretensio ning methods on the sma ll body occupant and large body occupant,and compar ing the d ifferences of protective effect w ith t he same pretensio ning method.The results show t hat the active pretensio n seatbelt device designed in t his paper has a good reliability,pretens ioning capabilit y and comfortable capab ility.Fo r the collis ion wit h the sa me speed,the aeb in the pre-crash can enhance the protect ive effect of the seatbelt on the occupants;in the five different seatbelt pretensio ning met hods inc lud ing retractor pyrotechnica l pretensio n,buck le pyrotechnical pretens ion,retractor reversib le pretensio n,retractor reversib le pretens ion comb ined w ith retractor pyrotechnical pretens ion,retracto r reversib le pretension co mb ined w it h buckle pyrotechnical pretens ion,retractor reversib le pretension co mb ined w it h buckle pyrotechnical pretens ion w ill have the best protecti ve effect on occupants;wit h the same pretens ioning method among the 5^{t h} percent ile fe ma le occupants,50^{t h} percent ile ma le occupants,95^{t h} percent ile ma le occupants,the seatbelt w ill have the best occupant protecti ve effect on the 50^{t h} percent ile male occupants.The results of this paper are of guid ing s ignifica nce to the applicat ion o f active pretens ion seatbelt device,the popular izat ion of aeb,the deve lopment o f new pretensioning methods,and the research of adaptive constraint systems.