Occupant response sensitivity analyses using a lumped mass model in simulation of car-to-car side impacts

Trella, Thomas J.; Kanianthra, Joseph N.

Affiliations

¹Transportation Systems Center, Research and Special Programs Administration

²U.S. Department of Transportation, National Highway Traffic Safety Administration

Abstract

Results of a sensitivity study, based on lumped spring/mass modeling approaches for the characterization of structural and occupant responses in 60° and 90° side impacts, are presented in this paper. Test data from collisions between a moving deformable barrier (MDB) and the side of a Volkswagen Rabbit in two crash configurations, simulating 60° and 90° impacts, are used to derive the force-deflection characteristics of the non-linear springs in the model.

The mathematical model is used to investigate the sensitivity of occupant responses to parametric changes in the striking and struck car characteristics. The variables included in this parametric study are striking vehicle and struck vehicle stiffnesses, crash configuration, impact velocity, occupant-to-door clearances, and padding characteristics. The striking car and struck car side stiffnesses are varied in the range of ±40 percent and ±30 percent, respectively, from the nominals. The effects of padding material characteristics and padding thicknesses up to 6 in are evaluated. The effects of the above parametric changes on predicted thoracic probability of injury using the National Highway Traffic Safety Administration (NHTSA) Thoracic Trauma Index (TTI) are also presented.

The results showed that the rib, spine, and pelvis peak accelerations generally increased with increases in striking vehicle stiffness and impact velocity. Increases in struck car side stiffness and the addition of door padding reduced the peak rib, pelvis, and spine accelerations. The results indicate padding is very effective in reducing the thoracic probability of injury. It is observed that the probability of injury at Abbreviated Injury Scale (AIS) levels of 3 or greater in a 30-year-old male will be reduced from 50 to 20 percent by adding a 3 in-thick padding in a 90° collision with the striking car moving at 26 mph and the stuck car moving at 13 mph, respectively. It is also observed that the relative effectiveness of the above changes in vehicle characteristics is a function of impact speed.

Links

SAE: 856089

Cited Works (2)

Year	Entry
1984	Eppinger RH, Marcus JH, Morgan RM. Development of dummy and injury index for NHTSA’s thoracic side impact protection research program. In: Proceedings of the SAE Government/industry Meeting & Exposition. May 21-24, 1984; Washington, DC. Warrendale, PA: Society of Automotive Engineers. SAE 840885.
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Cited By (3)

Year	Entry
1987	Trella TJ, Kanianthra JN. Analytical simulation of the effects of structural parameters on occupant responseisn side impacts of passenger cars. In: Proceedings of the 11th International Technical Conference on Experimental Safety Vehicles (ESV). May 12-15, 1987; Washington, DC.62-77.
1987	Hobbs CA, Langdon MG, Lowne RW, Penoyre S. Development of the European side impact test procedure and related vehicle improvements. In: Proceedings of the 11th International Technical Conference on Experimental Safety Vehicles (ESV). May 12-15, 1987; Washington, DC.92-103.
1989	Langdon MG. Developments in the simulation of side impact. In: Proceedings of the 12th International Technical Conference on Experimental Safety Vehicles (ESV). May 29–June 1, 1989; Göteborg, Sweden.1018-1032.