Abstract: Engine hoods are a main resource of pedestrian head injuries in vehicle-pedestrian impact. Six tests were made using child pedestrian head impactors, with the corresponding finite element model built and calibrated to improve pedestrian head protection. The energy absorption performances of five types of
hood inner structures were analyzed using a finite element model (FEM), with an asymmetric vehicle hood inner then designed according to the engine compartment layout of a kind of vehicle. The results show that the head injury criterion (HIC) at several areas of the hood inner is reduced to less than 1300, a few of which to less than 1000. Therefore, the pedestrian head protection is significantly improved using the asymmetric vehicle hood inner.

Key words: crash safety, vehicle-pedestrian impact, pedestrian head protection, vehicle hood inner, asymmetric design