Research On Development And Injury Evaluation Of A FE Model Of Traumatic Head Irjiury In Vehicle Traffic Accidents

Traumatic brain injury (TBI) is an important public health problem in society. The headis the most vulnerable part of the body. The probability of head injury in a car accident was54%, and its mortality rate was68%. TBI could not only lead to long-term cognitive,behavioral and emotional consequences for family, but also brought society enormousburden. And traffic accident can cause a variety of injuries in the form of skull fracture、contusion and DAI, which could not be observed by a crash dummy. Therefore, in order toreduce the incidence of head injury, predict the probability of head injury in the trafficaccident, the mechanisms of human brain injury should be researched more deeply.The finite element (FE) model was built based on CT and MRI data of a50th percentileChinese adult man in the subject. Firstly, use specialized medical3D software for geometryreconstruction of the head model, then the head meshes were established by software ofICEM and Hypermesh, and at last the complete finite element model of the head wasgenerated. The head model built in this paper included the main anatomical features:meninges, cerebrum, cerebellum, brain stem, ventricle, CSF, skull, facial bone, scalp, flaxand tentorium. The whole model was made up of94490hexahedral elements, and19949shell elements. The mass of the head model was about4.5kg. The material properties used inthis paper were taken from literatures published before.Foreign classical cadaver experiments data was used to assess the precision and stabilityof the head model. Nahum intracranial pressure experiment、Hardy skull-brain relativedisplacement experiment、 Trosseille intracranial dynamic response experiment andYoganandan head drop test were included. These classic experimental conditions werereproduced with LS-DYNA software, and then compared the simulation results with theexperimental data respectively. The results showed that the simulation results were in goodagreement with the experimental data, which proved that the model had good validity and biological fidelity. This model can be used to analyze the contact force, intracranial pressure,head acceleration and strain of the brain.On the basis of the model validation, Nahum’s and Hardy’s experiments were chose tostudy the influence of different skull-brain interface conditions on intracranial response. Theresults indicated that the skull-brain interface conditions had a big influence on intracranialpressure while the interface conditions had nearly no influence on relative displacementbetween skull and brain.Finally, the finite element head model was used to study head biomechanical responsesand injury mechanisms for different forms of collision (head translation and head rotation),including head impacting different foams obliquity and head impacting the B-pillar indifferent speed. According to the results of computer simulation, the evaluation to the headinjury could draw out by analyzing HIC value and physical parameters related to head injury.The results showed that different forms of head collision could result in different braininjuries. Also HIC was limited in predicting brain injury or other specific injuries, and itsuggested that contact force, intracranial pressure, head acceleration, stress and strain couldreflect the human head injury more comprehensively.