The aim of this paper concerns the development of a new finite element head model. A particular attention is focused on the representation of the skull/brain interface and the use of hyperelastic material is recommended to represent the cerebro-spinal fluid. The validation of this model is achieved by the comparison of its response with results obtained from cadaver impact tests. A second topic of this paper deals with an original scheme which is to find a correlation between numerical model response and head injuries. An accident reconstruction methodology has been developed. Based on numerical and experimental approaches, dynamic head solicitations generated during the accident are identified. By using these solicitations as input in the head model, interrelationships can be established between finite element head model response and injuries observed on in vivo human victims. Applied here to one accident case, a link can be built between inner brain contusions and “von Mises impulsive stresses”.

This work describes the mathematical modelling of motorcycle collisions with deformable structures. It has been developed over a number of years to the current stage where the intention is to investigate actual accident situations rather than pre-described tests. A section of this reconstruction task concerns the development and validation of the computer simulation of a motorcycle crash test. The purpose of this computer modelling is to identify the applied loads to the head by using a motorcycle model and dummy rider impacting an obstacle and to apply them afterwards to a FE model of the human head. The stress distribution obtained with the FE model will show how the brain is affected during this type of impact so that we can have an idea of the injury mechanisms developed. TRL has impact-tested many motorcycles and a recent test of a Norton Commander travelling at 50km/h impacting at 90degrees into the side of a stationary Ford Mondeo was chosen for the development purposes of a multi-body model. The multibody modelling approach has been done with the MADYMO package and the finite element analysis with PAMCRASH explicit code.

Numerical simulation of crash phenomena in rigid multi-body approach brings up problems when the various bodies constituting the mechanical system come into contact. The planar modeling of contact requires bodies' geometry to be taken into account. The method used permits the simultaneous management of constraints due to their contact and to kinematic joints, by introduction of holonomic constraints. We validate this method on Biomechanical applications. The results arising from a numerical model, and from a sled test, where we recreated the dummy seating conditions, are compared.