Dynamic Analysis of Cerebral Contusion under Impact Loading

The mechanism of cerebral contusion was studied by using finite element analysis. Prior to numerical analysis of a finite element human head model, experimental study of an impact loading for a water-filled acrylic cylindrical container was carried out. The frequency of fluctuation of internal pressure was close to the natural frequency of the acrylic container. The human head model was analyzed by finite element analysis and the numerical result was compared with the result of the experimental study reported by Nahum and good agreement was obtained. In impact analysis, mass and velocity of the impactor were changed so as to keep the energy constant and intracranial pressure fluctuations of the impact side and the opposite side were obtained. When the input force duration was short, the thumping pressure fluctuation between the positive and negative pressure with higher frequencies were observed both at the impact side and the opposite side. As the input force duration became longer, the pressure fluctuation was suppressed and the positive pressure became dominant at the impact side and the negative pressure became dominant at the opposite side, and lower frequencies became dominant.