Thle5^th%Occupants Injury Mechanism Study And New Occupant Restraint System Design Of Passenger Car

Generally, the fatality of female passenger has achieved a certain degree ofimprovement, and the added fatality risk for female decreases greatly. However, adultwomen have25to30-pecent higher fatality risk, given similar physical insults, than menof the same age. And women are exceptionally more vulnerable to neck and abdominalinjuries. The early safety technologies and design changes tended to benefit young adultmales somewhat more than other groups, consequently augmenting slightly the relativerisk increases for females. More recent technologies such as air bags, pretensioners, andload limiters, perhaps becaouse they were developed with a deeper understanding ofbiomechanics and human tolerance limits, have substantially reduced the excess risk offemales relative to male occupants.For the front row, the latest research of occupantrestraint system, pays more and more attention on female occupants, and has begun theshifton adaptive occupant reatraint system and intelligent occupant restraint system. Forthe second row, recently study has shift from the simply multi-parameter optimization ofoccupant system to exploration of the noval occupant restraint system, such as Airbelt,head airbag, etc. And for the OOP female driver, in the exception of low risk deploymentairbag, more other redesigns are proposed.Based on the analysis of the reqiurements and test results of5th%ile occupants, it isfound that, compared with other assessment programs,U.S.NCAPis the most stringentassessment program all over the world, not only for the5th%ile occupant, but also for the50th%ile occupant. Moreover, outboard5th%ile passenger in the front row has higher HIC15and Nijwhen compared with50th%ile driver, and5th%ile passenger has worse injuries inneck and thorax compared with50th%ile. Last but not least, the major injury place of OOPfemale driver is neck.In this paper, the injury mechanisms of5th%ile occupant’s neck and thorax are analyzed detailedly. Specifically, from the U.S.NCAP’s neck assessment indicator(Nij), themechanism of neck My, the mechanics relationship between head and neckinjuries, therelationship between neck and thorax acceleration, the mechanism of thorax accelerationand displacement, and the influnce factor of thorax accemeration under torso rotationcircumstance are discussed.For current situation of the low scoring rate of the second row5th%ile passenger inCNCAP, the benefit of inflatable belt airbag is verified by simulation method. With theadoption of inflatable belt airbag, the neck and thorax injuries of the second row5th%ilepassenger are improved obviously. Moreover, a kind of automatic control device for airbagdeployment is proposed aim at FMVSS208regulation. With simulation method, it isconfirmed that the proposed device can reduce the neck injury of OOP female driverwithout obvious influnce on the normal protection capability of airbag.