Brain tissue constitutive material models and the finite element analysis of blast-induced traumatic brain injury

Traumatic Brain Injury (TBI) often occurs due to assaulting loads such as blast on the human head. Finite Elements (FEs) can approximately simulate blast interactions with the human head. An important parameter in the FE modelling procedures is the accuracy of constitutive formulation of the brain tissue. This paper focuses on implementation of three brain tissue constitutive relations to measure and compare the dynamic behaviour of the brain under identical blast loads. For the geometry, a simple spherical head model is employed to monitor the brain tissue response and examine the uncertainties in FE brain tissue constitutive modelling. The brain tissue is constitutively modelled as hyperelastic, viscoelastic, and hyperviscoelastic material types. Intracranial Pressures (ICP), strains, and shear stresses as the dynamic parameters are measured with time. These biomechanical parameters can be compared against the injury thresholds. Our analyses show that although the results of ICPs and strains are close for the three models, shear stresses are considerably different. The study will further provide a new insight into selecting a proper constitutive model of the brain tissue under dynamic conditions.