Optimization And Design Of A Large-sized SUV's Front-end Structure For Pedestrian Lower Limb Injury Protection

According to the survey results of the state information center,the actual sales volume of SUV was 10.24 million in 2017,achieving the sales target of 2022 five years ahead of schedule.With the surge of SUV sales and the number of traffic accidents increased significantly,we put forward to new security requirements for SUV,especially seven-seat large-sized SUV.Due to the traffic mode of human-vehicle hybrid road in China,traffic safety accidents of vulnerable road users such as pedestrians are more prominent.Therefore,this paper optimized the design of the front-end structure of large-sized SUV to improve the the level of protection for lower limb injuries of vulnerable groups such as pedestrians.In this paper,a seven-seat large-sized SUV under development was selected as the prototype.To carry out independent positive research of the development of pedestrian injury protection.Firstly,based on the finite element theory,the collision simulation model of SUV vehicle model and FLEX-PLI lower limb impactor(2018 version C-NCAP)was established,while the validity of the model was verified through physical experiments;Secondly,based on the impact analysis method,the inluential regular of front-end structural parameters on lower limb injuries of pedestrians was revealed;Then,the SUV vehicle front-end structure was optimized based on DOE test design and multi-objective optimization algorithm;Finally,the new aPLI lower limb impactor(2021 version C-NCAP)was used to verify the protective effect of the optimized vehicle front-end structure on lower limb injuries of pedestrians.The main research contents of this paper are as follows:1.RAIODSS software was used to establish the collision simulation model between the SUV vehicle model and FLEX-PLI lower limb impacter(2018 version C-NCAP).After verifying the validity of the simulation model,the lower limb injury value and kinematic response analysis of the simulation results of L0 collision position were conducted.2.Based on the influential analysis method,the influential regular of lower support structure,middle support structure and upper support structure's parameters on lower limb injuries of pedestrians were respectively revealed.3.Based on the orthogonal array method(DOE test design method)and the NSGA-?multi-objective optimization algorithm,optimising the vital parameters of vehicle front-end structure,The optimization result significantly improved the damage protection performance of the front-end structure of to the lower limbs of pedestrians,and has good protection effect for d ifferent collision positions,4.At the top of the FLEX-PLI leg impactor(2018 version C-NCAP),adding weight to simulate the new aPLI lower limb(2021 version C-NCAP),and establish and vehicle collision simulation model in L-2 collision position,with FLEX-PLI damage parameters and kinematic response of the lower limbs impacter were respectively analyzed,which further research the influence of the protection performance evaluation of SUV vehicle front-end structure after using aPLI new legs.