Modelling of Whiplash Trauma Parametric study of rear-end impacts using FEM and CFD

Abstract

This work is a combination of Finite Element (FE) modelling and Computational Fluid Dynamics (CFD) to investigate the effect of acceleration pulses, head restraint and seating posture on facet joint loads and pressure transient magnitudes on the neck injury outcome during whiplash motion. A parametric study is carried out with the FE human body model THUMS (Total HUman Model for Safety) for a variety of crash pulses and crash conditions that have a known relative risk of long term neck injuries in rear-end impacts. The injury criterion NIC (Neck Injury Criteria) is addressed for the studies made. The THUMS model is used to generate the motion data of the spinal canal, which is used as an input to simulate the behaviour of the spinal canal to analyse the pressure transients in the network of blood vessels during the whiplash motion performing CFD simulations using the OpenFOAM CFD toolbox. Using the output of FE simulations, a moving mesh technique is used to achieve the motion of the mesh points in the CFD simulations. The results give an insight into proposed injury mechanisms and injury risk assessment criteria concerning long term neck injuries. The effect of head restraint and its position with respect to the driver’s head in mitigating the above injuries is discussed for different crash scenarios.