Citation

Viano DC. Proc. IRCOBI 1987; 15: 135-148.

Copyright

(Copyright © 1987, International Research Council on Biomechanics of Injury)

DOI

unavailable

PMID

unavailable

Abstract

There are many opinions on the injury reducing benefit of energy-absorbing material for side impact protection. The objective of this study was to develop a methodology to link reductions in biomechanical responses due to force-limiting material to projections of injury mitigation in real-world side impact crashes, and to use this approach to evaluate the potential injury reducing benefit for the chest and abdomen of crushable material in the side door and armrest. Using a simulation of the human impact response, a range in crush force was determined which effectively reduced a peak biomechanical response from that obtained with a rigid impact. The range in constant crush force depended on the velocity of impact. The higher the velocity of impact, the higher the level of crush force to achieve a reduction in the peak response. National crash severity study (NCSS) field accident data for car-to-car side impacts provided information on the occupant exposure and injury as a function of the change in velocity of the struck vehicle. Based on various experimental studies, the velocity of the side door at contact with the occupant's chest is similar to the change in velocity of the struck vehicle (about 60% of the closing speed of the striking vehicle). The chest impact velocity in the simulation was assumed equal to the observed change in velocity in the NCSS data. This related the simulation data to real-world injury data. Reductions in biomechanical response were related to lower injury risk. This enabled a calculation of a reduction in injured occupants for the velocity range in which the energy absorbing material was effective. The greatest reduction in seriously injured occupants was found with relatively soft energy absorbing materials that are effective in the lower-speed (change in velocity = 4 -8 m/s) crashes, whereas padding was negligibly effective in high-speed crashes (change in velocity greater than 10 m/s). (TRRL)