Dynamic Response And Damage Analysis Of Human Head And Neck In Automobile Rear Impact

Neck injuries caused by car accidents are a serious problem worldwide.The damage in this area can be life-threatening and it will have a long-term impact on the lives of survivors even if it is not fatal.Post-crash may result in sprain or strain of the neck soft tissue.However,the mechanism and location of whiplash injuries remain unclear.At present,many researchers have carried out related studies on low-speed vehicle collision and achieved some results,but the research on the neck tissue stress and the injury of high-speed rear collision is less involved.In recent years,with the rapid development of road traffic,traffic accidents at high speed become more frequent,and the injuries to human body may be more fatal,resulting in more serious consequences.This paper establishes a head and neck biomechanical model based on human anatomy to study the force and damage of the neck under different speed rear collisions.The main work is as follows:(1)The establishment of the head and neck model.The model was based on CT scans of the head and neck,using the medical processing software MIMICSfor three-dimensional bone reconstruction,then the intervertebral disc and facet joints were generated in 3-MATIC.Meshing and optimizing operations with HYPERMESH,and then establishing three-dimensional solid ligaments and muscles of the neck based on anatomical structures.The resulting models include: the head,8 vertebrae(C1-T1),6 intervertebral discs(including annulus,nucleus pulposus,upper and lower cartilage endplates),facet joints(including articular cartilage and joint capsule ligament),ligaments,muscles,etc.(2)Model validation.The model was compared and verified with foreign classic experiments,including axial impact,flexion and extension,rotation and lateral flexion experiments of cadaver head and neck.The curves of impact force and head acceleration obtained by axial impact simulation are in good agreement with the experimental data,and the motion degrees of adjacent vertebrae obtained by flexion and extension,rotation and lateral flexion simulation are basically consistent with the experimental data,thus verifying the high bionics and effectiveness of the model.(3)Simulation of rear collision.First,head and neck motion simulation under rear impact at different speeds(20km/h,40km/h,60km/h and 80km/h)was conducted.Through the force analysis of various tissues in the neck,it can be found that no damage appeared in the neck at the speed of 20km/h,but in the speed collision simulation process at 40km/h,60km/h and 80km/h,different degrees of damage were generated and the earliest damage was in the ligament structure.Then,the effects of different headrest distances(20mm,50 mm and80mm)on neck force at the same collision speed were studied.The results show that reducing the distance between the head and the headrest could effectively lower the risk of neck injury.Finally,some reasonable suggestions are put forward for the protection of human neck injury in the rear collision.