Although there have been a number of significant advances in recent years in the field of crash injury mechanisms and assessment, clearly there is still much to be learnt in terms of head injury minimisation and prevention.

A cost-effective approach to designing and optimising head protection systems is to use numerical methods, such as the Finite Element (FE) method. To achieve this a detailed understanding of the behaviour of the major components of the head and how they interact, with wave propagation and focusing effects, during an impact or abrupt deceleration event is required. The resultant stresses, forces, strains, accelerations, etc. which vary as a function of time, then need to be translated into material tissue failure mechanisms that represent observed injuries.

A preliminary FE model of the head and cervical spine is presented and the results from a simulated blow to the head using the FE code LLNL DYNA3D. The skull and brain are modelled with 3D solid ‘finite elements’ to capture the approximate geometrical structure. The skull is modelled using an existing elastic-plastic material model with failure. The porosity term is used to represent the cellular and crushable bone material, while bone fracturing is modelled using a tension based brittle failure model.

Soft tissues are modelled using a viscoelastic material model, and the interface between the skull and the brain is modelled using a frictional slide-line, thus allowing the brain to rotate within the skull.