Measurement and simulation of energy absorption behaviour of motorcycle helmet materials

Abstract

Head injuries are one of the most frequent injuries resulting from a motorcycle accident, highlighting the importance of motorcycle helmets. The effect of repetitive minor impacts, such as from drops or knocks, on the ability of a motorcycle helmet to absorb energy is an area that has not been heavily researched in literature. Thus, the aim of this thesis is to investigate the effects of these repetitive impacts on the ability of motorcycle helmet materials to absorb impact energy. In addition, this thesis is aimed at evaluating the appropriateness of material models and finite element techniques for the application of simulating degradation of energy absorption of helmet materials. ABS plastic outer shells and expanded polystyrene foam liners were selected as the materials to be investigated due to their prevalence as motorcycle helmet materials.Drop-weight impact testing was carried out on flat plates of ABS and expanded polystyrene, these plates were impacted a total of 10 times each for 15J of impact energy. Two grades of expanded polystyrene were investigated, VH (28kg/m 3 ) and VVH (38kg/m 3 ). Energy absorption behaviour was investigated thorough processing of force-

UQ eSpace

“…Matrix Composite to a Drop-Weight Impact Event [1] and in Tai's thesis project [25]. Testing was carried out on the epoxy control samples and the modified PEI/epoxy samples.…”