Car driver protection at frontal impacts up to 80 km/h (50 mph)

Pipkorn, Bengt; Mellander, Hugo; Håland, Yngve

Affiliations

²Traffic Safety Research and Engineering AB, SWEDEN

Abstract

The structures of modern passenger vehicles are designed to maintain integrity up to an impact velocity of about 64 km/h (40 mph). The occupant protection system is likewise designed to efficiently protect the occupant up to an impact velocity of 64 km/h. However, there are highways with a 90 km/h (56 mph) speed limit without separation of the lanes and many car occupants still die in severe frontal crashes.

To investigate the level of occupant protection at very high impact velocity a full frontal full vehicle rigid wall crash test with a mid size passenger vehicle was carried out. The impact velocity was 80 km/h (50 mph). A 50%-ile Hybrid III crash test dummy was positioned on the driver side. The dummy results show that the possibility of survival of an occupant in that particular vehicle in such a crash was minimal.

With the goal to develop a protection system that in an 80 km/h (50 mph) crash test would result in dummy reading below the FMVSS 208 injury criteria levels a mathematical sled model was developed and a mechanical sled mock-up was set up. The mathematical model was validated by means of results from the mechanical sled tests.

To identify the parameters of the occupant restraint system with the greatest influence on the efficiency of the restraint system factorial analysis was used in which a number of parameters were varied at two levels. The parameters were preloading of seat belt, load limiting of seat belts, gasgenerator output, steering column yield distance and airbag volume.

Using the results from the factorial analysis a mathematical sled simulation and a mechanical sled test were carried out with a restraint system that was designed give reasonable protection to an occupant at an 80 km/h (50 mph) impact. The restraint system consisted of a large volume airbag, a significantly longer ride down distance than what is available in the vehicles today, diagonal and lap belt pretensioning and load limiting. Efficient occupant driver protection in 80 km/h (50 mph) full front rigid wall crash seems to be possible. However, the interior ride down distance needs to be greater than what is available in the vehicles on the market today.

Links

URL: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv19/05-0102-O.pdf

Cited By (3)

Year	Entry
2009	Pipkorn B, Kullgren A. Effects of active structures on injuries in medium severity frontal impacts. In: Proceedings of the 21st International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 15-18, 2009; Stuttgart, Germany.
2006	Pipkorn B, Mellander H, Olsson J, Håland Y. On the combined effect of the variation of driver restraint configuration and crash pulse for high and very high impact velocities. In: Proceedings of the 2006 International IRCOBI Conference on the Biomechanics of Impact. September 20-22, 2006; Madrid, Spain.199-211.
2007	Pipkorn B, Mellander H, Andersson T, Olsson J. Means of crash pulse variation and the injury reducing potentials in moderate and high severity frontal impacts. In: Proceedings of the 2007 International IRCOBI Conference on the Biomechanics of Impact. September 19-21, 2007; Maastricht, The Netherlands.301-310.