에너지 흡수재의 종류와 그에 따른 FMVSS201 Head Impact 성능 개선에 대한 연구

It should be a key factor to maintain enough space between the headliner back surface and body steel structure in order to meet the requirement of FMVSS201 S6, which assesses head injury by impacting Free Motion Headform (FMH) to upper interior parts. The factor, however, is not practical solution in vehicle development because it conflicts with customer’s needs that require roomy interior space. Meanwhile it is highly demanded to reduce the gap between headliner and body structure as vehicle development is repeated. It is getting more important to adopt a proper countermeasure which warrants performance under the unfavorable condition in FMVSS201 standpoint. The understanding of the energy absorbing characteristic for each kind of countermeasures would be a stepping stone to choose proper one. So this paper highlights merits and demerits of widely used countermeasures in the aspect of raw material, manufacturing process and cost as well as energy absorbing characteristic based on quasi-static component tests. The characteristic is also compared quantitatively by a parameter derived from the waveform efficiency. And FMVSS201 head injury performance is compared according to the type of countermeasure through FE analysis.