Research On Rear Female Occupants' Injury Protection And Optimization Of Restraint System In Front Crash

According to the data,in the case of car crashes,frontal collision is the most common in all collisions,but the restraint of the rear occupants depended on is not perfectly complete compared to the front occupant while collision occurs.And traffic accident statistics also prove that in recent years,the risk of injury of rear occupants increased significantly,it's safety is not superior to the front.In order to improve the ability of cars to protect the rear passengers in the collision accidents,it's required in C-NCAP to carry out the safety study of the rear female passengers by force.The research on the injury protection of the rear occupants is aimed at not only the normal sitting people,but also the non-normal sitting(out-of-position)occupants,so as to optimize the parameters of the restraint system,and provide the direction for development of intelligent constraint system.Making the 2015 version of the C-NCAP code as modeling and evaluation basis,combined with the analytical theory of CAE numerical simulation and ISIGHT optimization,a restraint system simulation model for rear female occupants under 100% front crash of a listed SUV is established,and so is the optimal workflow of the constrained system.The main contents are as follows:(1)Establish a full vehicle model of SUV frontal collision,then introduce RADIOSS's female dummy,and adjust the posture according to the C-NCAP test requirement,so that the dummy can sit on the seat stably.(2)Set up the simulation model of rear restraint system and fit it well with the dummy,after the important parameters are set up,the calculation is made.By comparing the head and chest acceleration,chest compression,left and right pelvis force,pelvis acceleration with test results,verify the reliability and validity of the simulation model.(3)According to the article information and survey,select four of the most common forms of rear occupant posture and carry out simulation,compare this four situations by the head and chest acceleration,chest compression,left and right pelvis force,pelvis acceleration,from the damage curve obtain the protective effect of restraint system on rear occupant(4)According to the actual manufacturing process and improvement feasibility of the automobile,preliminary select cushion friction coefficient,D-ring friction coefficient,lap belt friction coefficient,shoulder belt friction coefficient,cushion stiffness,ignition timing,backrest stiffness,preload force duration,preload force as variable parameters,make reducing the chest compression and neck tension and improving the test score of rear seat occupants as goal,use optimization software ISIGHT to establish a multi-objective optimization model of RADIOSS and response surface approximate model between the various parameters,finally through gradient algorithm optimization method to optimize the approximation model to get a scheme to make chest compression,neck tension and rear occupants score better.This paper has significance in researching injury protection of rear seat occupants and development of Intelligentized restraint system,The simulation method,the optimization method and the conclusion have guiding significance for rear passengers' safety optimization design of the SUV.