Research On The Non-linear Finite Element Constitutive Model Of Human Head In Automobile Collision

With the development of automobile industry,more and more attention has been paid to vehicle safety.China's expressway mileage and vehicle ownership are also increasing year by year.Head and neck injuries are also increasing in traffic accidents.Head injury in traffic accidents has become the most serious injury type because of its high lethality.With the progress of computer technology,experiments that can not be implemented at ordinary times can be simulated in computer p rograms.In order to study the craniocerebral injury in traffic collision,the finite element model of head has been established as an important tool to study injury biomechanics.However,the overall quality control of finite element models,the standardi zation of material parameters and the prediction of damage threshold are urgent problems to be solved.In order to establish the head finite element model needed for this study,medical imaging technology combined with computed tomography(CT)and magnetic resonance(MRI)was used to improve the digital image recognition and various mesh generation techniques to obtain the three-dimensional point cloud data of the head and neck of the human body with detailed anatomical structure.The 3D model of the head was established by using the Mimcs software point cloud data,and the head of the head was set up.Then the model is divided and optimized.From the study of the nonlinear characteristics of biological materials,the constitutive model and material parameters used to simulate the brain tissue are discussed.By comparing the advantages and disadvantages of different constitutive models,the Mooney-Rivlin equation is used to describe the hyperelastic line of brain tissue,and the accurate material parameters is obtained according to the literature.A hyperelastic finite element model which is more suitable for human tissue is constructed.After building the finite element model,we verified the model by relevant cadaver experiments in the ABAQUS software,incl uding Nahum intracranial pressure cadaver experiment and Trosseille intracranial dynamic response test.By modifying the material parameters of the brain tissue,we compared the hyperelastic model and the linear viscoelastic model and found that the hypere lastic model has better biological fidelity.This study is of great significance for the biomechanical response of head and neck injuries and the development of safety protection devices.