Abstract:

For the safety design of motorcycle helmet, it is necessary to study the influence of the energy absorption capacity of the liner foam under the impact load on the protective performance of the motorcycle helmet. A finite element model of the helmet was established and the effectiveness of the model was verified
according to the drop test in the regulation ECE R22.05 by the Economic Commission for European. Twelve drop test simulations were performed by changing the foam density corresponding to different test points. The results show that when the foam density increases at the test points of front, crown, and rear from 40 kg/m3 to 80 kg/m3, the energy absorption capacity of the foam increases, which makes the impact energy of the head decay faster. The risk of skull fracture at the three test points increases from 25%, 55%, and 39% to 53%, 96%, and 96%, respectively. However, there is not clear evidence of the relation between the skull fracture risk and foam density at the right lateral area of the helmet. Therefore, the safety design of the helmet should take into account both the density and size of the liner foam.

Key words: motorcycle helmet safey, energy absorption, foam density, drop simulation, head skull fracture risk