Research On Simulation And Improvement Of Vehicle Crashworthiness Based On Two Frontal Impacts

The crash safety weighs the most among all the performance of the vehicle, and the occurrence of frontal impact has a higher rate than other kinds of impacts. According to the statistics, Frontal impacts of which are 30%～40% and 90%～100% overlap caused the most serious injuries. Because 100% RB and 40% ODB frontal impact evaluate different aspects of crashworthiness, they can complement each other well, and the crashworthiness can only be studied comprehensively when combined two frontal impacts. Therefore it’s necessary to take both 100% rigid barrier (100% RB) and 40% offset deformable barrier (40% ODB) frontal impacts into consideration when research vehicle crashworthiness. Research vehicle crashworthiness taking both frontal impacts into consideration is significant to enhance vehicle crash safety and reduce injury.Finite element method is applied and a car finite element model is built. Then both frontal impact finite element models are built based on the car model. According to the crash simulation based on GB 11551-2003 and ECE R94.01, the crashworthiness is analyzed. Depending on the weak points of crashworthiness in both frontal impacts, bumper trestle and front side member are improved, and wheel carrier connecting bar is added. The strength of compartment is enhanced, and crashworthiness in both frontal impacts is improved. The vehicle crashworthiness in both frontal impacts is enhanced. A feasible method was offered to improve the crashworthiness in both frontal impacts. The research content and conclusion are as follows:(1) Vehicle FE model and two frontal impact FE model are built up, and vehicle FE model is verified. FE modeling standard is founded and key factors that influence simulation results are researched.(2)The crashworthiness in two frontal impacts is analyzed in terms of vehicle deformation, key parts energy-absorbing ability, crash pulse and passenger compartment intrusion, engine compartment energy-absorbing percentage and so on. Structure optimization and material replacement are applied to main energy absorbers depending on the weak points of crashworthiness in both frontal impacts.(3) The simulation results demonstrate that the deformation mode of the right side member and bumper trestle is improved, and the peak value of deceleration is decreased 6.1g in 100% RB impact, while in 40% ODB impact the compartment intrusion by A pillar, steering wheel, instrument panel and toepan is reduced remarkably, and the deformation mode of the engine compartment is improved.