A new three-dimensional (3D) human head finite element model (FEM) has been developed and partially validated against experimental data. This model consists of the scalp, skull, dura, falx, tentorium, pia, cerebrospinal fluid (CSF), venous sinuses, ventricles, cerebrum (gray and white matter), cerebellum, brain stem, and parasagittal bridging veins. A frontal impact and a sagittal plane rotational impact were simulated. The 3D simulation results showed that differentiation between the gray and white matter and the inclusion of the ventricles are necessary in brain modeling. Although both the homogeneous and inhomogeneous brain models predicted almost the same intracranial pressure response intracranial pressure response of the brain, they predicted a different shear stress response. Simulation results suggest that coup/contrecoup injuries are pressure induced, while brain-stem injuries are caused by shear stress/strain. The impact response of parasagittal bridging veins, simulated by using one-dimensional string element, appeared to be reasonable and consistent with experimental results. The model predicted that the bridging veins in the central part of the superior sagittal sinus were at higher risk of rupture as they could be subjected to higher tensile strains during the rebound phase. This could be an important injury mechanism for subdural hematoma which also depends on the direction of impact.
Abstract