Head injury prediction tool for protective systems optimisation

This paper presents an original numerical human head FE models followed by its modal and temporal validation against human head vibration analysis in vivo and cadaver impact tests from the literature. The human head FE model developed presents two particularities : one at the brain-skull interface level were fluid-structure interaction is taken into account, the other at the skull modelling level by integrating the bone fracture simulation. Validation shows that the model correlated well with a number of experimental cadaver tests including skull deformation and rupture, intra-cranial pressure and brain deformation. This improved numerical human head surrogates has then been used for numerical real world accident simulation. Helmet damage from eleven motorcycle accidents was replicated in drop tests in order to define the head’s loading conditions. A total of twenty well documented American football head trauma have been reconstructed as well as twenty eight pedestrian head impacts. By correlating head injury type and location with intra-cerebral mechanical field parameters, it was possible to derive new injury risk curves for injuries as different as subdural haematoma and neurological injuries. Illustration of how this new head injury prediction tool can participate to the head protection system optimisation is also provided.