Simulation And Optimization Of Structure Crashworthiness Of A Passenger Car In Rear-end Collision

According to the relevant department statistics,the incidence of the rear-impact is third only to front and side impact.This type of accidents ranked first of all accidents in the proportion on national highway, and the rate is also growing. The fires resulting from fuel spillage are likely to happen in the accidents, which can lead to additional property losses and casualties. Passenger car rear-end crash is one of the major categories of the urban road traffic accidents,so research on crashworthiness in the rear-end impact is desirable and this research is crucial.According to the new FMVSS 301 requirement and"Passenger cars rear–impact fuel system safety requirements"GB 20072-2006, Two FE model of passenger car was built and validated with available experiment data to make an analysis of the rear impact. By comparing the largest plastic strain of the fuel tank, the deformation of the rear part of vehicle and the requirements of the two FE simulation models, analysis the influence of the two regulations to design and improvements of the rear part of vehicle.In order to study fuel system stability and crashworthiness of the rear-end collision, according to"Passenger cars rear–end fuel system safety requirements"GB 20072-2006 a finite element model of car was adapted based on a certain passenger car from a local manufacture. The structures of the rear part of the vehicle were optimized by using orthogonal experimental design (OED) and multi-objective algorithm methods, it is effective to reduce the risk of oil leak and improve the crashworthiness of the rear impact.According to simulation results, the following conclusions were made:By comparing the largest plastic strain of the fuel tank, the deformation of the rear part of vehicle and the requirements of the two FE simulation models which built according to the new FMVSS 301 requirement and"Passenger cars rear–impact fuel system safety requirements"GB 20072-2006 , the new FMVSS 301 was more More suitable for assessment of rear-end collision.Through the application of multi-objective algorithm, the thickness of rear rail and the rear crash box was optimized. After the optimization, the maximum effective plastic strain of the fuel tank was reduced by 10.3%, the energy absorption of the extension of rear rail and rear crash box increased by 13.8%, the deformation of the rear suspension area was reduced by 45.3%. Thus, it is effective to reduce the risk of oil leak and improve the crashworthiness of the rear impact.