Further investigation of the applicability of head injury criterion and the associated scaling laws with finite element modelling

Abstract

To test the applicability of Head Injury Criterion (HIC), three different-sized (5th, 50th, 95th percentile) finite element head models were developed from medical CT scan images of living humans. These models were scaled to generate six scaled models. The skulls of these nine models were defined as deformable and rigid bodies, respectively. It was found that both coup and contrecoup pressures decreased from the smaller head to the larger one when the skulls were deformable; while the opposite trends were found when the skulls were defined as rigid bodies. Maximum principal strains and maximum share stresses increased from the smaller head to the larger one for both deformable and rigid skulls with much larger increases in the rigid skull cases. It also found that there were larger discrepancies in intracranial responses between scaled models and the original ones, which invalidate the scaling laws used in biomechanical injury studies.