Optimization Research Of SUV Inner Hood Based On Pedestrian Head Protection

In recent years,with the increase of automobile production and ownership in China,problems of traffic safety are widely concerned by people.In vehicle collision accidents,death rate of pedestrian collides with SUV is twice as much as that with ordinary car,head injury is the important cause of pedestrian deaths.Because accident in-depth investigation and reconstruction can provide valuable reference data for vehicle passive safety research,and adult head mainly contact with hood in traffic accidents,reasonable structure design can improve the pedestrian head protection performance of hoods.So combined with real accidents,optimization research of SUV inner hood based on pedestrian head protection has theoretical and practical significance.This presentation is based on the data of traffic collision accidents,with the aid of multi-rigid-body dynamics software and finite element software to carry out the following works:(1)According to SUV-pedestrian collision accidents which are in the Songjiang database of National Automobile Accident In-Depth Investigation System(NAIS),this presentation analyzes SUV-pedestrian collision characteristics,summarizes accident forms and contact position of pedestrians in the SUV-pedestrian front and side impact,then expounds mechanism of pedestrian head injuries and evaluation index in the collision accidents.(2)This presentation selects a typical SUV-pedestrian collision accident from the Songjiang database of NAIS to conduct an in-depth investigation,which is the collection of environment information,SUV information and pedestrian information,uses PC-CRASH multi-rigid-body dynamics software to reconstruct,then exports the corresponding pedestrian head dynamic response parameters and the pedestrian head damage parameters.(3)The SUV and pedestrian head collision model is established on the basis of a real accident,the division of collision test area and selection of test point on engine hood are defined.The head collision parameters(collision speed and collision angle)in the accident are taken as initial conditions of the finite element simulation,then the collision model is simulated and analyzed by following the laws and regulations and meeting the stiffness requirements under different conditions.The validity of the collision model is verified by comparing measurements of SUV engine hood sag and pedestrian head damage location in the real accident with the simulation results.(4)This presentation establishes a mathematical model of optimal design about the SUV inner hood.Firstly,it applies the comprehensive test design method to get 25 groups of test schemes,utilizes CAE parametric method to select the optimal design variables and finite element software to simulate the collision;Secondly,it uses the response surface method and genetic algorithm to obtain an optimal solution for inner hood design parameters;Finally it analyzes the pedestrian head protection performance of the inner hood before and after optimization and then verifies validity and feasibility of the optimization scheme.