歩行者頭部保護を目的とした自動車エンジンフード補強板構造の衝撃緩衝特性

抄録

Motor vehicles on the market are required to undergo the pedestrian head protection test since 2004 and engine-hoods need to meet the required standards for pedestrian head protection performance in addition to primary performance. The engine-hood of motor vehicles is evaluated by the pedestrian head protection performance test according to the Head injury criteria (HIC) which is calculated by 3-dimensional coordinate (x, y, z) of acceleration generated on the head impactor. All car manufacturers are recently required to consider protecting pedestrian heads when developing the engine-hood. It is important to control the acceleration time history at the initial stage and late stage for pedestrian head protection. The engine-hood for pedestrian head protection needs to control local rigidity and whole rigidity by just one structure. To solve this problem we focus on inner panels which have a dominant role in absorbing energy. This study also aimed at evaluating the impact characteristics of inner panels adopting folded panels to improve pedestrian head protection by numerical analysis. As a result, it was found that the inner panel could complement the performance of outer panel. In addition, the folded panel structure help to control the amount of displacement and it was effective in the reduction of HIC.