Measuring Head Restraint Force and Point of Application During Low-Speed Rear-End Automobile Collisions 970397
In order to assess the head and neck kinetics of human subjects exposed to low-speed rear-end impacts, a method for measuring the magnitude and line of action of the force between the head and the head restraint was required. In addition to being accurate and repeatable, the design was required to maintain original seat back and head restraint geometry, mass, stiffness, and height adjustment. This paper presents a design using strain gauges applied to the head restraint tubes, upper seat back, and custom replacements for brackets attaching the head restraint to the seat back. The background theory and free-body analysis, the analog math circuitry, and a dynamic calibration procedure are presented. Overall force magnitude and line-of-action errors are quantified, and a sample output from a human subject undergoing a rear-end collision with a speed change of 8 km/h is presented.
Citation: Lawrence, J., Siegmund, G., and Nickel, J., "Measuring Head Restraint Force and Point of Application During Low-Speed Rear-End Automobile Collisions," SAE Technical Paper 970397, 1997, https://doi.org/10.4271/970397. Download Citation
Jonathan M. Lawrence, Gunter P. Siegmund, Jeff S. Nickel
MacInnis Engineering Assocs.
SAE International Congress and Exposition
Occupant Protection and Injury Assessment in the Automotive Crash Environment-SP-1231, SAE 1997 Transactions - Journal of Passenger Cars-V106-6