Effect of Seat Belts Equipped with Pretensioners on Rear Seat Adult Occupants in High-Severity Rear Impact

This study provides a preliminary investigation of occupant kinematics for rear seat occupants involved in high-severity rear impacts. The effect of a seatbelts equipped with or without a pyrotechnic pretensioner on restraining the rear seat adult occupant was evaluated. Further, the study examined the result of the occupant's seating alignment by comparing a Nominal Seating Position (NSP) to an occupant whose torso would be rotated forward to be placed in a Moderately Displaced Position (MOP) prior to impact. A series of eight sled tests were performed using a deceleration sled subjected to a delta-V of 30 mph. Instrumented HIII 50th and 5th ATDs were positioned in the outboard, rear seating positions. The study found that pretensioners had little effect on the occupant kinematics of rear seat occupants in either the NSP or the MOP. But, there were marked differences in kinematic evaluations between the occupant seating alignment configurations. HIC 15, HIC 36, Ncf, Nte, Ntf, peak chest acceleration, and peak, resultant pelvis acceleration all increased when the occupant's torso was displaced forward prior to the rear impact.