Static and dynamic energy absorption of aluminium honeycombs and polymeric foams composites

The use of innovative materials as energy absorbers for motorbike helmets might have a significant impact in the safety of motorbike riders, currently among the most vulnerable road users. In this regard, the effect of the interaction between aluminium honeycombs and polymeric foams in the design of innovative liners is investigated by studying their behaviour under compressive loading conditions. Quasi-static and impact compressive loadings were applied to samples of twolayered structures made of aluminium honeycombs and expanded polystyrene foams, in order to observe their deformation modes, determine their energy absorption properties and the influence of the loading speed in their mechanical response. The same tests were performed on the expanded polystyrene foams and on the honeycomb layers separately. The results were compared and it was shown that although aluminium honeycombs alone offer the highest energy absorption levels, their coupling with EPS foams is preferred for the protection of the head.