The Study Of Factors Affecting Occupant Injuries In Frontal Collision

With the increase of car ownership,the incidence of automobile collision accidents has continued to increase,and the collision safety performance of vehicles has been increasingly valued.The occupant restraint system and occupant sitting posture are inextricably linked to the degree of occupant injuries during the collision.Therefore,in order to improve the safety performance of the vehicle during the collision,it is necessary to study the influence of relevant parameters on occupant injuries.At present,in the occupant safety research,most of the studies mainly focus on the effects of research parameters on injuries to one or several parts of the occupant.In addition,most researches use the injuries indexs specified by the regulations to measure the occupant’s injuries during the collision,and do not consider the occupant’s injuries outside the regulations.At the same time,most studies only consider the independent effect of the research parameters on the occupant injuries,while ignoring the effect of the interaction between the parameters on the occupant injuries.In view of the above deficiencies,when evaluating the occupant injuries,this study not only paid attention to the common injury indexs in the regulations,but also considered the lumbar spine injury index that were not specified in the regulations,that is,the maximum axial force of the lumbar spine.And based on the existing weighted injuries method,a new method for calculating WIC value including lumbar spine injuries was proposed.This paper also studied the effect of the interaction between risk factors on the WIC value.Firstly,this paper established a finite element collision simulation model and simulated it in a frontal collision based on LS-Dyna finite element simulation platform.The response of the dummy’s head,chest,neck,leg and other parts in the simulation results were basically consistent with the test results,which verified the accuracy of the model and indicated that the model could be used for subsequent research.Then based on the verified model,the occupant injuries under four different crash pulses were compared,the results showed that the comprehensive injuries caused by the earlier severe crash pulse with the peak value of the pitch angle to the occupant was greater than other crash pulses,so this pulse was selected as a parameterized study crash pulse.Next,in the sensitivity analysis,seven parameters of shoulder belt load limit,coefficient of friction between dummy and seat cushion,anchor pretensioner,dynamic locking tongue,lap belt angle,seat structure(anti-submarining bar)and occupant posture were selected as the research variable.By changing the value of a single variable,the sensitivities of each variable to the each part injuries and weighted injuries WIC value of the occupant were obtained.Finally,in order to further determine the statistical significance of each variable on the each part injuries and WIC value and the effect of the interaction between the variables on WIC value.This study refered to the results of the sensitivity analysis to screen the study variables,and then used the full factor test design method and variance analysis method to carry out a significant analysis of the risk factors affecting the occupant injuries.This paper uses numerical simulation to carry out a comprehensive parameterized research and analysis of the risk factors that affect the occupant’s injuries during the frontal collision.It provides a theoretical basis for understanding the risk factors closely related to occupant injuries during vehicle collision and how to reduce occupant injuries in vehicle safety design.