Influence of helmet inertial properties on neck injury risk during ejection: A numerical human model approach

Abstract

Survival rate after jet ejection is about 94%, but 50% of major injuries are due to neck injuries. Mechanical parameters responsible for those injuries are not yet fully understood. The purpose of the present study is to use a existing finite element model to investigate helmet mass and inertial properties influence on neck injuries that may occur during ejection. The model position represented the head-neck in a specific MK16© ejection seat, with a functional 30° oblique inclination. Vertical acceleration was imposed in order to simulate the first 350ms ejection event. Then the case of bare head and three alternative existing helmets were considered. All the quantified parameters are under failure level and these results could be explained by a helmet weight less than 2Kg. Furthermore, no shock due to the parachute opening or windblast effect is modelled. Indeed, the simulation represents the first 350ms of an ejection, and there was no relative speed during the experiment. © 2005 Springer.