Simulation of Blast-Head Interactions to Study Traumatic Brain Injury

This paper presents a methodology for predicting the mechanical damage inflicted on the brain by a high explosive (HE) detonation and leading to traumatic brain injury (TBI). A brain model, with its complexity, is used in the computational procedure. The processes of HE detonation and shock propagation in the air, as well as their interaction with the head, are modeled by an Arbitrary Lagrangian Eulerian (ALE) multi-material formulation, together with a penalty-based fluid/structure interaction algorithm. This methodology provides intracranial pressure and maximum shear stress within the microscale time frame for this highly dynamic phenomenon. Two scenarios are simulated. In one scenario, the brain is in close proximity to a 1lb trinitrotoluene (TNT) explosion, and the other to a 0.5lb explosion. The resulting countercoup intracranial pressure-time histories, from the 1 lb TNT explosive scenario, demonstrates that pressure falls below −100 kPa. This can cause cavitation bubbles and damage to the brain tissue. The simulations also predict that the areas of high pressure and shear stress concentration are consistent with those of clinical observations. These resulted intracranial pressure and shear stress responses are the parameters to examine against injury criterions thresholds.