Research On The Mechanism Of Pedestrian Head Landing Injury Based On The Reconstruction Of Human Vehicle Collision Accident

In recent years,due to the rapid development of road facilities and the rapid increase of car ownership,the frequent occurrence of road traffic accidents not only causes great loss to public property,but also brings great threat to people's lives.Among all road users,pedestrians are in the most vulnerable position,and there is a very high risk of casualties in traffic accidents.According to the statistical data of pedestrian injury location,in all traffic accidents,the traumatic brain injury(TBI)of the head under the impact load of vehicles and other vehicles has become the main factor of pedestrian death and injury.Therefore,it is very important to carry out the analysis of pedestrian head injury in traffic accidents.First of all,the paper reviews the development of the finite element model of human head,and then based on the multi rigid body model and the finite element model,describes the research status of the pedestrian head tribal damage in the collision accident.Secondly,based on two real cases of vehicle pedestrian collision,this paper analyzes the accident reconstruction by using the scene information,vehicle front features and anthropometric parameters recorded in the accident investigation report.Through the simulation of the accident scene,the whole process of the accident is reproduced,and the pedestrian dynamic response and pedestrian injuries are analyzed in detail.By comparing the results of real traffic accident and accident reconstruction,such as brake trace,final stop position of vehicle and pedestrian damage,the feasibility and accuracy of the pedestrian vehicle collision model are verified.Then,based on the multi-rigid body model,the different dynamic responses of pedestrians caused by different vehicle types,collision speeds and angles are analyzed,and the severity of pedestrian injuries is determined by combining the damage evaluation indexes.The results show that in the case of low and medium speed collision,the head landing injury caused by the collision between pedestrians and vans is lower than that caused by ordinary cars.The speed is also an important factor affecting the head landing injury.When the speed reaches more than 40 km/h,the risk of head injury begins to increase significantly.In addition,the impact angle will significantly affect the movement posture of pedestrians after collision.The head landing damage caused by pedestrians in frontal collision is often more serious than that in side collision.Based on the multi-body dynamics simulation,the regular conclusions can be drawn by summarizing the results of multi group simulation tests.However,in order to clarify the injury mechanism of head tribe damage,the next step is to obtain the detailed mechanical parameters through the finite element simulation for further study.Finally,on the basis of the human head model established by our research group,we choose foreign classic cadaver experiments to verify its effectiveness.Taking the dynamic parameters of pedestrian head landing obtained from accident reconstruction as loading conditions,the finite element model of pedestrian head ground collision is established.The stress-strain response of brain tissue was simulated and analyzed by finite element method.Combined with the actual trauma in the accident,the injury mechanism of pedestrian head landing injury was analyzed and the risk of pedestrian head injury was evaluated.The conclusion of this study is helpful to the diagnosis and treatment of the landing injury in clinic,and has some reference significance to the design of passive safety of vehicles,the development of pedestrian protection measures,the improvement of traffic protection measures and the formulation of safety regulations.