Design of an innovative optimized motorcycle helmet

A key component of a safety helmet is the foam liner, which absorbs the greatest portion of impact energy during an accident. The aim of the present study is twofold: to design a motorcycle helmet equipped with an innovative liner optimized with regard to energy absorption and to do so by coupling engineering expertise with design of experiments and response surface modelling. The new liner consists of an acrylonitrile butadiene styrene plastic lamina shaped into deformable cones. Energy is absorbed via a combination of folding and collapsing of the cones. The main advantage that such a liner may introduce over common expanded polystyrene pads are that it allows a better optimization of energy absorption for different impact sites and configurations. Design of experiments was used to identify the most relevant parameters in the definition of the mechanical behaviour of the cones. Design of experiments and response surface modelling were then used to design a helmet with optimized performance. Finally, the performance of the newly designed helmet was compared with that of its existing commercial counterpart. Simulations exhibit in seven of the eight impact cases required by the standards a reduction in the maximum acceleration or the head injury criteria coefficient