The purpose of this investigation was to develop a better understanding of the effect of crash pulse magnitude and shape on occupant injuries. To this end, several idealized frontal crash pulses were used in an occupant simulation, from which the corresponding injury criteria were calculated. The idealized pulses ranged from simple step pulses to two stage pulses that are more comparable to actual vehicle accelerations. Finally, the effect of 5-10 ms duration spikes in different portions of a typical crash pulse was evaluated. From the results of these simulations, several conclusions were drawn. For the constant acceleration level pulses, the lower magnitude, longer duration pulses resulted in lower injury criteria. However, most crash pulses do not have a single constant acceleration level. For the two stage acceleration pulses, it was found that the injury criteria were reduced as the magnitude of the first stage of the pulse was increased and the level of the second stage was decreased, while holding the total crush space constant. Finally, it was determined that a 5-10 ms spike in the accelerations would significantly affect the injury criteria, regardless of the time at which these spikes occurred. The dummy injury criteria calculated in the simulation for these different pulses were compared. For the covering abstract see ITRD E825082.
Abstract