샌드위치 복합재가 적용된 저상 버스 차체 구조물의 충돌 특성 평가

This paper describes the results of crashworthiness of low-floor bus made of sandwich composite. The applied sandwich composite of structure was composed of WR580/NF4000 glass fabric/epoxy laminate composite facesheet and aluminum honeycomb core. Crashworthiness analysis of low-floor bus was carried out using explicit finite element analysis code LS-DYNA3D with lapse of time. Material testing was conducted to determine the input parameters for the composite facesheet model, and the effective equivalent damage model for the orthotropic honeycomb core material. The crash condition of low-floor bus was frontal accident with speed of 60km/h at rigid wall. The results showed that the safety region of driver was secured against frontal crashworthiness. Also, the modified Chang-Chang failure criterion was recommend to evaluate the failure mode of composite structures after crashworthiness event.