Injury Patterns and Effective Countermeasures for Vehicle Collision Compatibility

This paper examines the National Automotive Sampling System (NASS)-Crashworthiness Data System (CDS) statistics to identify the significant parameters associated with injuries in light truck based vehicle (LTV) to car frontal collisions. These parameters of interest are the ΔV of the colliding vehicles, the direction of impact as well as any underride of the smaller vehicle. It is observed that the cumulative ΔV curve of car occupants in frontal towaway collisions with LTVs becomes asymptotic at 30 mph and that over 97% of those car occupants are in cars with a ΔV of 35 mph or less. The relationship of injuries with the reported under-ride in the NASS database is more complex and in several ΔV ranges, the presence of under-ride is related to a lower risk of injuries. Based on these findings, evaluations of compatibility improvement are conducted for frontal impact between an LTV and a small car at approximate ΔV of 35 mph and intrusion levels are calculated for the struck car. It is concluded from the data presented here that lowering the height of LTVs to increase the vertical overlap with a smaller vehicle may, in many cases, increase the intrusion levels in the smaller vehicle as well as increase the crash energy in the smaller vehicle. The addition of a secondary structure to LTVs for the purpose of increasing structural interaction is also investigated and it is shown that the effect of this in the studied cases is to reduce the calculated intrusion in the smaller vehicle.