Abstract
Keywords Pedestrian protection, Active bonnet, Car-to-dummy collision, Headform-to-bonnet impact, HIC
Abstract In vehicle-pedestrian impact, the majority of pedestrian fatalities are caused by head injuries. Accident analysis showed that bonnet of car often had consequences with severe head injuries in accidents involving young pedestrians. Important factor involving risk of head injury is design of bonnet structure, often supported by underlying reinforcement and engine bay structures. Design of those structures has the potential to reduce the severity of the resulting head injuries
This work takes a closer look at pedestrian head impact mechanics and protection, when impacting with compact passenger car. Discussion of influence of chosen passive and active pedestrian restraint systems to impact responses of impacting pedestrian body is aim of the study. The influence of the active bonnet as representative of active restraint systems and bonnet structure modifications as representative of passive restraint systems is investigated and compared with help of mathematical modeling.
Both simulations of dummy vehicle collision and headform impact test ware carried out, impact responses ware measured and according to injury criteria the relevant influence of active restraint system to injury risks was discussed. While the headform test was simulated and HIC, stopping distance and peak force ware assessed on different points of bonnet when influence of bonnet structure design was investigated. The bonnet consisted of two parts: skin and under-skin structure. Both parts of bonnet were modified for purpose of this study. The modifications of sub-skin frame ware designed to provide better support of bonnet skin at those points where limit values of criterions ware exceed. Polyurethane foam or was considered when bonnet skin was modified. All modifications ware subject of headform test simulations.