Blast and the Consequences on Traumatic Brain Injury-Multiscale Mechanical Modeling of Brain

Abstract : A multiscale finite element analysis for the human head and brain injury analysis has been developed. At the continuum macroscale, the human head is subjected to shock loads from explosions and blasts. A multi-material ALE formulation is implemented to model the air-blast simulation. LS-DYNA as an explicit FE code has been employed to simulate this multi-material fluid structure interaction problem. The 3-D head model is constituted of the detailed structure of the human head anatomy, including the brain, falx and tentorium, CSF, dura mater, pia mater, skull bone, and scalp. In various types of analysis, the impacts of many parameters such as the distance from the explosion site, the head orientation, neck stiffness, and the intensity of the explosive materials have been studied. At the microscale an algorithm utilizing finite element method for micromechanical characterization as well as analysis of axons and extracellular matrix (ECM) is developed to examine the Diffusion Axonal Injury (DAI) often causing the TBI. The material properties of both the axons and the ECM are assumed to have a viscoelastic behavior. The impact of parameters such as the undulations of axons as well as axon/ ECM volume fractions within different subregions of the brain has been examined.