The two known systems for restraining vehicle occupants in a crash situation are the seat belt and the air bag. A series of head-on crash tests against a barrier indicated that these restraining devices present widely different G waveforms for the chest of a dummy seated behind the steering wheel as the crash pulse becomes more severe. The dummy chest, when restrained by a seat belt, showed a gentle G waveform, while with an air bag, it presented another waveform with unusual spikes. An analysis of the test findings reveals that spikes in chest G are always accompanied by similar spikes in G for the pelvis. It was found that this is attributable to a substantial shock when the dummy's upper leg contacts the molded upper leg contacts the molded pelvic structure which suggests that the existing dummy might have some structural deficiency. Another series of crash tests was carried out on an improved air bag system using softer knee bolsters.
Abstract