Research On Operating Coach Rear-end Collision Simulation And Rear-structural Crashworthiness

Under the trend of High-speed development of technology, more and more attention is paid to the automotive safety researches. The domestic automakers are working hard to improve the safety performance of their products, making every effort to get a higher star in the C-NCAP test or the collision regulations in order to promote sale and enhance the competitiveness of their products. In recent years, the traffic accident statistics at home and abroad show that the proportion of dead people in bus collision and rollover accidents is particularly high. Until now the occupant protection regulations about the rear-end collisons has not be formulated at home and abroad. So refering to the protection legislation of frontal crash, the rear-end collision simulation analysis of 6127-type and 6756-type coaches are operated in this paper. The main reason of neck injury and the related factors of simulation results in rear-end collision are preliminary understood. The achievement provides a certain reference for real car test, computer simulation and formulating regulations of rear-end collision in the future.Based on the statistics and analysis of the road traffic situation in recent years, two operating coach finite element models are established using Hypermesh. And then using LS-DYNA program, two coaches'simulation analysis in rear-end collision are operated according to the relevant research material in domestic and foreign. The influences of collision vehicle speed, quality and collision coincidence rate on vehicle structure and occupant safety are analysed. The related factors (panel skin, window glass and collision vehicle material) which have effect on rear-end collision simulation results have also be compared.Simulation results show that the rear passenger dummy neck Nkm value is bigger than the middle and front dummy Nkm value, with the increase of vehicle speed and quality, crew neck Nkm has also increased.40% of the coincidence is less than 100% of the rear-end collision, and has less damage to the crew neck. The panel skin has more effect on the rear-end collision simulation results. The collision vehicles with all rigid material influence the simulation results more and the front with elastic-plastic material and the back with rigid material influence less. Meanwhile, according to the simulation results on passenger cars, the back structure is improved; the energy absorption device is installed and analyzed the safety of the crew after improving body structure. The results show that the improved scheme can be used to improve energy absorption of passenger rear buffer structure, improve vehicle occupant safety. In addition, according to the process of simulation analysis, the recommendation of evaluate behind collision security with computer simulation methods is proposed.