Oblique Impact Analysis on Kenaf (Hibiscus Cannabinus) and Flax (Linum Usitatissimum) Natural Fiber Sport Cycling Helmets

This paper represents the performance of a natural fiber cycling helmets in an oblique impact with a simulated road surface. The linear accelerations and impact energy of a head form that weight four kilogram were measured and calculated. Helmet standards require helmets to be designed only to survive a simple drop test onto an anvil. The maximum permitted deceleration of the dropped head form is typically 300g, which is equivalent to an impact velocity of 20 km/h (12.5 mph). Two helmets being tested suspended onto a guided drop-table in the particular desired impact orientation. Just before impact, the test object is released from suspension so it can move unrestrained thereafter. The main advantages of this process are that the object is free to move naturally during impact which provides for more realistic drop-testing. For oblique impact test, all helmets that tested pass the requirement that is set by EN1078:2007 by having linear acceleration below than 250g in a free fall 1.5 m platform. By comparing the linear acceleration resultant with an existing cycling helmet in the market Kabuto Aero SL, flax aero helmet shows 11.82% linear acceleration resultant loss with 214.16g. Kenaf helmet recorded 168.48g with 30.63% linear acceleration resultant loss from the Kabuto helmet and 21.33% linear acceleration resultant loss from the Flax helmet.