Volunteer and Dummy Head Kinematics in Low-Speed Lateral Sled Tests

Abstract

Understanding human head kinematics prior to the safety countermeasure activation is important to help minimize potential for injury in side impact and rollover situations. The objective of this study was to compare three volunteers and the Hybrid III responses in three low-to-moderate lateral crash pulses. The parameters evaluated were lateral pulses and belt usage. A total of 24 tests were carried out in a side impact sled. The subjects consisted of two 50th percentile males (Volunteers 1 and 2), one 5th percentile female (Volunteer 3) and a Hybrid III 50th percentile male. All subjects were in near-side impacts. The pulses consisted of two 4 g pulses (6 and 8 kph) and a 4 g/8 kph followed by a m 2.5 g pulse to simulate a low curb impact. In the 6 and 8 kph pulses, the antropometric test devices' head trajectory is somewhat similar to the volunteers'. For near-sided/belted occupants, the peak lateral excursion was 327 - 53 mm for the volunteers, and 269 mm for the Hybrid III in the 6 kph pulse, while it was 321 - 35 mm respectively in the 8 kph pulse. It was also observed that, in the first phase of the motion, the Hybrid III vertical displacement remained positive while the volunteers' vertical displacement was initially negative. This is probably due to the rigidity of the Hybrid III spine and the lack of flexibility in its torso compared to humans. In the 4 g/8 kph followed by a m 2.5 g pulse, the lateral head excursion was higher with a Hybrid III than with volunteers. For near-sided/belted occupants, the lateral excursion was 155 - 10 mm for the volunteers and 291 mm for the Hybrid III. The results suggest that the Hybrid III is a useful tool to evaluate head kinematics in slow-speed lateral impacts at 6 and 8 kph. For the 4 g/8 kph pulse followed by a m 2.5 g pulse acceleration, a better correlation between the Hybrid III and volunteer head excursion may be needed to improve the biofidelity of the Hybrid III kinematics.