Traffic fatalities have been decreasing to less than 5,000 for the past 5years. However, pedestrian fatalities account for over 30% of all traffic-related deathsand are not decreasing while the others are decreasing. It therefore follows that it is anurgent task to decrease pedestrian fatalities. Head injuries are evaluated by Head Injury Criterion(HIC)whichis a measure of the likelihood of head injuryarising from an impact.Thevariable is derived from the acceleration/time history of an accelerometer mounted at the centre of gravityof a dummy’s head, when the dummy is exposed to crash forcesinduced byvehiclehoods.
This paperstudies generation mechanism of pedestrian head acceleration induced by head impact on vehiclehoodsin traffic accidents.The study also tries to clarify factors which make the head acceleration occurin order tofind out the efficient countermeasures from the perspective of passive safetyby modelling the phenomena of head impactor on vehicle hoods mathematically. The factors clarified by the mathematical model were validated by experimental and numerical methods.