The Research On Occupant Neck Injury In Vehicle Rear-end Collision With Different Overlap Rate

With the healthy and stable development of China’s economy and the improvement of people’s quality of life,China’s vehicle ownership has always maintained a growing trend,which on the one hand has accelerated the development and progress of society,but also brought road traffic safety problems that can not be underestimated.Rear-end collision is one of the most important traffic accidents and the main type of occupant injury is neck injury.The mechanism of neck injury is complex and difficult to detect,which can easily cause long-term pain and other injuries.At present,the evaluation of automobile neck protection performance at home and abroad is mainly based on whiplash test,but the actual vehicle rear-end collision will have a certain offset rate.Therefore,the study of occupant neck injury in vehicle rear-end collision with different overlap rates is more comprehensive and more in line with the real collision scene,which has a certain theoretical and practical significance.In this project,a rear-collision occupant hybrid model with real neck structure was used to load the load output from simulation of rear-end collision with different overlap rates to study the difference of occupant neck injury in rear-end collision with different overlap rates.Combined with the simulation results,appropriate neck evaluation indexes were selected to study the influence of seat design parameters on occupant neck protection performance,and relevant improvement measures were proposed.The main research methods are as follows:(1)Ten groups of rear-end collision simulations with different overlap rates were carried out based on a verified vehicle finite element model,and the credibility analysis and kinematic response analysis of the simulation results were carried out.(2)Based on the kinematic response of the occupant’s head and neck,such as acceleration and relative displacement,and the statistical data of stress distribution of cervical vertebra and intervertebral disc,the effects of different overlap rates on occupant neck injury in rear-end collision were studied and analyzed,and the model was verified.(3)According to the simulation results of vehicle rear-end collision with 40%overlap rate,the impact of seat design parameters on occupant neck injury in rear-end collision was studied by referring to neck injury evaluation indexes of C-NCAP whip test method in 2021 edition,and seat optimization suggestions were proposed to reduce the risk of occupant neck injury.The results show that the simulation results of rear-end collision are effective,and the output acceleration response can be used to study the occupant neck injury.There are significant differences in neck injury of passengers in rear-end collision with different overlap rates.In the case of 40% overlap rate,all relevant data are obviously larger,indicating a higher risk of neck injury of passengers.The probability and severity of neck injury can be effectively reduced by shortening the headrest gap,increasing the headrest height and increasing the headrest stiffness,and decreasing the backrest stiffness above the seat and increasing the backrest stiffness below the seat.The relevant research data and conclusions in this paper can be used to supplement and improve the evaluation method of occupant neck protection performance,and provide reference for the design of safer car seats.