Biomechanical Analysis of the Sensitivity of Brain Tissue Responses to FE Head Models in the Study of Impact-Induced TBI

Abstract A numerical investigation is conducted on the injury-related biomechanical parameters of the human head under blunt impacts. The objective of this research is twofold; first to understand the role of the employed finite element (FE) head model — with its specific components, shape, size, material properties, and mesh size — in predicting tissue responses of the brain, and second to investigate the fidelity of pressure response in validating FE head models. Accordingly, two independently established and validated FE head models are impacted in two directions under two impact severities and their predicted responses in terms of intracranial pressure (ICP) and shear stress are compared. The coup-counter ICP peak values are less sensitive to head model, mesh size, and the brain material. In all cases, maximum ICPs occur on the outer surface, vanishing linearly toward the center of the brain. Hence, it is concluded that different head models may simply reproduce the results of ICP variations due to impact. Shear stress prediction, however, is mainly affected by the head model, direction and severity of impact, and the brain material.