A method to evaluate the benefit of energy-absorbing material fob side impact protection

Viano, David C.

Affiliations

¹Biomedical Science Department, General Motors Research Laboratories, Warren, MI 48090-9055

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. 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 (AV) 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 AV 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 AV 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 EA material was effective. The greatest reduction in seriously injured occupants were found with relatively soft EA materials that are effective in the lower-speed (AV = 4 - 8 m/s) crashes, whereas padding was negligibly effective in high-speed crashes (AV > 10 m/s).

Cited Works (5)

Year	Entry
1973	Lobdell TE, Kroell CK, Schneider DC, Hering WE, Nahum AM. Impact response of the human thorax. In: King WF, Mertz HJ, eds. Human Impact Response: Measurement and Simulation. Proceedings of the Symposium on Human Impact Response held at the General Motors Research Laboratorie; October 2-3, 1972; Warren, MI. New York, NY: Plenum Press; 1973:201-243.
1976	Kroell CK, Schneider DC, Nahum AM. Comparative knee impact response of part 572 dummy and cadaver subjects. In: Proceedings of the 20th Stapp Car Crash Conference. October 18-20, 1976; Dearborn, MI. Warrendale, PA: Society of Automotive Engineers:585-606. SAE 760817.
1985	Rouhana SW, Foster ME. Lateral impact: an analysis of the statistics in the NCSS. In: Proceedings of the 29th Stapp Car Crash Conference. October 9-11, 1985; Washington, DC. Warrendale, PA: Society of Automotive Engineers:79-98. SAE 851727.
1985	Viano DC, Lau IV. Thoracic impact: a viscous tolerance criterion. In: Proceedings of the 10th International Technical Conference on Experimental Safety Vehicles (ESV). July 1-4, 1985; Oxford, England.104-114. SAE 856025.
1982	Malliaris AC, Hitchcock R, Hedlund J. A search for priorities in crash protection. In: Proceedings of the SAE International Congress & Exposition. February 22-26, 1982; Detroit, MI. Warrendale, PA: Society of Automotive Engineers. SAE 820242.

Cited By (2)

Year	Entry
1991	Fildes BN, Lane JC, Lenard J, Vulcan AP. Passenger Cars and Occupant Injury. Monash University Accident Research Centre, Cr95. Canberra, Australia: Federal Office of Road Safety; March 1991. Report No. CR95.
1994	Fildes BN, Lane JC, Lenard J, Vulcan AP. Passenger Cars and Occupant Injury: Side Impact Crashes. Canberra, Australia: Federal Office of Road Safety; April 1994. Report No. CR 134.