DefinePK

Abstract

Bicycle helmet is currently available to cater to general head sizes, ranging from S/M and L/XL, but there is also a universal model that can fit all sizes through adjustable helmet strap. However, numerous surveys addressed that wearing helmet is not comfortable and the current sizing did not accommodate the range of the user. This is due to the collective report of human anthropometric data that the human head shape and dimension are different according to ethnic groups, age and gender. This paper describes impact attenuation of user-centred design approach of bicycle helmet in accordance to AS/NZS 2063:2008, Australian/ New Zealand Standard for bicycle helmet using validated simulation model of drop impact test. The objective of this paper is to investigate the effect of changing the shape of the liner to improve fit of bicycle helmet, hence the user-centred design approach, on the impact attenuation properties of the helmet. Head scans of 5 participants were taken using Artec3D portable scanner, while bicycle helmets and J head form were scanned using Flexscan 3D scanning equipment. A customized helmet design based on the shape of each participant was developed and tested using validated drop impact simulation model at front, top and side impact locations. The thickness and peak linear acceleration of original helmet and customized user-centered helmets were also measured. The results revealed that the user-centered helmet recorded different PLA value compared to the original helmet because liner dimension and thickness was changed to accommodate the head shape of the participants. The finding of this study suggests that the PLA of the helmet depends on the helmet liner thickness. It was also found that generally changing the liner thickness to employ user-centered helmet design would alter the impact performance of the helmet.