This paper on "FE Modelling of a Protective Helmet - Parametric Study and Coupling with the Human Head" was presented at the NAFEMS World Congress on The Evolution of Product Simulation From Established Methods to Virtual Testing & Prototyping - 24-28 April 2001, The Grand Hotel, Lake Como, Italy.

Abstract

The aim of the present work was to develop a full face helmet finite element (FE) model based on the dynamic behaviour of its components measured experimentally. The helmet shell was characterised by modal analysis methods and the protective foam constitutive equations were derived from impact tests. Helmet model validation was conducted against a frontal impact with a dummy head coupled to the helmet model. A parametric study of the model permitted to define the sensitivity of the model response to shell and foam properties as well as their interface characteristics. When validated, the helmet model was coupled to an existing 30 human head FE model in order to estimate the intra-cranial field parameters in terms of normal and shearing stresses for a normative impact test on a flat anvil, after having checked the influence of fluid-structure coupling formulation for cerebro-spinal fluid (CSF) on model response. The estimated intra-cranial stresses suggested that some brain tolerance limits were reached in this impact configuration, in terms of shearing stresses. It was concluded that tools are now available for helmet optimisation against biomechanical criteria.