Finite element modelling of helmeted head impact under frontal loading

Finite element models of the head and helmet were used to study contact forces during frontal impact of the head with a rigid surface. The finite element model of the head consists of skin, skull, cerebro-spinal fluid (CSF), brain, tentorium and falx. The finite element model of the helmet consists of shell and foam liner. The foam is taken as elasto-plastic, the brain is assumed to be viscoelastic and all other components are taken as elastic. The contact forces and coup pressures with helmet on the head are much lower than in the absence of the helmet. A parametric study was performed to investigate the effect of liner thickness and density on the contact forces, pressures and energy absorption during impact. For 4 ms⁻¹ velocity, expanded poly styrene (EPS) foam of density 24 kgm⁻³ gave the lowest contact forces and for the velocities considered, thickness of the foam did not affect the contact forces.