Building And Analysis Of 3D Finite Element Model Of The Human Skull And The Study On The Distribution Of Stress

Biomechanics is a cross-subject, which is the application of engineering mechanics to organism. Biomechanics of Head Injuries is foucusing on the study of the dynamic response of the brain under the load outward, and then deduce the generation mechanism of skull rupture,bumped injury of brain tissue, and bring forward corresponded defending measures to reduce appearance rate of the head damage,reduce mortality and the rate of deformity owing to head damage。A great number of head damage experiments have been made in the domestic and abroad, which includes three ways, more specifically, animal experiment, clay experiment and non-biology model. This article adopts the latter two ways.Experimental Stress Analysis is an important part of plasmodium mechanics. In the engineering work ,for some important components, in additional to analyzing and calculating them by using general theory ,examining them by experimental methods is necessary. By using experimental method to search stress distributing of structure, we can measure the practical structure, or we can measure the model, and then converse this to the practical structure .When Components is pressed , the interior of it appear stress and distortion. Although stress can't be measured directly, the distortion of it can be measured. Then gain the stress by Hooke's Law .In the recent years , the research of Brain Injury of Bio-mechanics often uses computer emulator and FEM simulation. Compared to experiment mechanics, Computational Bio-mechanics has many merits,that is the smaller invest ,the less risk, the quicker action, and the higher effect. The article scans the head with Multi-slice Spiral CT, reconstruct the three-dimension model by medicine modeling software–Mimics, then construct three-dimension model of skull by Ansys, analyze and calculate them, and observe stress distributing of the skull in the computer experiment .By impacting the skull and constructing three-dimension FEM model of skull, analyze by FEM mechanics, compare the data of them. When The skull is being impacted, 1st principle stress of skull and the distributing of 1st principle strain can be gained ,which provide theory according to diagnose the damage and fracture of the skull. At the same time, explore constructing three-dimension FEM model of full skull and the method of FEM analysis .The article contains three parts:The first part :Using the skull simulates the circumstance of parietal, knocking simulate the outside force, which contains two ways: :the same force on different part and the different force on the same part. Knocking the skull, collecting correlated data by dynamic strain test system, analyzing and disposing by the correlated theory, and then gaining the the magnitude and direction of 1st principle stress and 1st principle strain of the surface of the skull. .The second part : Faultage scan by hyper-helix CT, make layer thickness being 0.625mm, reconstruct the three-dimension model of skull by medicine modeling software–Mimics, and crave up and optimize the gridding.The third part: Transmit three-dimension model of skull to FEManalysis software-Ansys, simulate the two forces of force application, and then gain FEM analysis result. Compare the two results, validate FEM model,and confirm 1st principle stress and 1st principle strain distributing of the skull.The conclusion of the research:(1)Gained two experimental data in the two forces, calculated the magnitude and aspect of the main stress, gripped stress distributing of the other part when the skull is being stressed.(2)Scanned the organism by CT, reconstructed the three-dimension model of skull by medicine modeling software–Mimics, which is convenient, rapid and exact. The quality of model lies on the layer thickness and craftiness extent of handling Mimics, the more mastership, the high quality. By observing and compare, our model is close to the skull entity.(3) Transmitted three-dimension model of skull to FEM analysis software-Ansys, simulated the two forces of force application, gain FEM analysis result. Compared the two results and the result of FEM analysis , discovered the two results anastomose well, proved it is feasible that basing on CT scanning ,using Mimics software, reconstructing model, and then analyzing by FEM mechanics.