Development And Verification Of A Highly Bionic FE Human Head Model

Vehicles have been a crucial tool for people on travelling as the development of the modern society.Multiple problems also come along with the convenience provided by vehicles,every year there were about 1,250,000 people killed in traffic accidents.Among all the accidents,head injury is the type mostly involved.Therefore,it is significant to research the head traumatic brain injury mechanism under crash condition,for the purpose to reduce road accident casualties and improve automobile security.In the study of head injury,the finite element(FE)model has become the main method of head injury research due to plenty of advantages,such as flexibility in modeling,repeatability of experiments,intuition of results and low cost etc.Lots of FE models have been established for the study of human head injury mechanism,and obtained many beneficial results.However,due to the complexity of the head structure and physiological function,these models still have a lot of improvement compared with real structure.According to a 50 percentile Chinese adult male CT and MRI data,a high degree of craniocerebral FE model is been established and verified by simulations based on classical head corpse experiments.Also,this paper discussed about the biomechanical response to the head together with different types of headrest during the process of rear-ends accidents with the simulating results.The contents of the full text are as follows:A 3D FE model with asymmetric structural is built up with a great precision of human brain based on the 50 th percentile of adult men head CT and MRI scan slice data.Three-dimensional geometric extraction,geometric smoothing,finite element meshing,and material definition of brain medical imaging were completed.The model contained the detailed structure of the cerebral cortex,and also divide the brain function area,the thalamus,ventricle,cerebellum,brain stem,corpus callosum and other structures were refined to ensure that the head of the FE model and real structural function in the degree of bionic consistency.Refer to the relevant literature to define the material parameters of the model.The data from four classic dead body experiments by Nahum,Trosseille,Yoganandan and Hardy are adopted in this thesis to validate the head FE model been built.So that the model and the results of previous experiments in the intracranial pressure,acceleration and relative displacement of the brain and other indicators have a high degree of consistency,make sure that the results of the model and the real experimental are similar.In the end,use the head FE model to simulate the biomechanical response of the head together with different types of headrest during the process of rear-ends accidents.The results show the follow situations: when HIC is greater than 1000,the intracranial pressure also beyond head injury threshold,the results of both evaluations are consistent;when HIC is smaller than 1000,there is injury risk because of the high intracranial pressure;when both HIC and intracranial pressure are smaller than damage index,there is still injury risk due to excessive strain in the head.Head FE model can not only get head HIC,but also can calculate damage index such as intracranial pressure,stress,strain etc,is an effective means to study the head injury in the collision.It's more comprehensive for passengers' protection by judging injury situations from different injury thresholds.FE model can predict head injury from multiple damage parameters,compare with machine model,it's more effective.