An evaluation of the influence of crash pulse shape on the risk to sustain injuries in medium severity frontal collisions was carried out by reconstructing a number of real world accidents using mathematical simulations. Ten crashes with restrained occupants, recorded crash pulses and known injury outcomes were selected for reconstruction. The crashes were selected from the Folksam accident database. Delta-V and mean acceleration were derived from the recorded crash pulses. The injury outcome was collected from hospital records and questionnaires and coded according to the 2005 version of AIS. Only restrained occupants were included. Computer simulations using a mathematical model of the 50th percentile Hybrid III dummy were used to evaluate the influence of the crash pulse on the loading of the occupants. The restraint system was a state of the art system with a driver side airbag and a belt system equipped with a pretensioner and a load limiter.Simulations were carried out in which the crash pulse shape was varied according to what can be achieved with the frontal longitudinal beam in which the crush force can be varied. Injury reducing benefits for the occupants were achieved by varying the crash pulse shape in medium severity impacts. The principal technical solution to vary the crash pulse is to pressurize the frontal longitudinal beams in the frontal structure prior to impact. In low and medium-speed impacts, the beams are not pressurized to use the available crush distance of the vehicle front. In high-speed impacts, the beams are pressurized to increase the force level of the beam and use the available crush distance of the vehicle front efficiently. The full text of this paper may be found at: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv21/09-0380.pdf For the covering abstract see ITRD E145407.
Abstract