The study on impact behavior of helmet shell reinforced with different length of coir fiber

Abstract

The aim of this research was to study on the application of coir fiber for composite material which is used for motorcycle helmet shell. Also the aim of the study was to examine the effect of fiber length on the crashworthiness capacity of motorcycle helmet shell under impact. The widely-used commercial open-face helmet type was used in this study. The study was conducted using computer simulation model and compare to the previously available experiment for validation. In order to achieve mechanical property of the composite material for construct the computational model, a number of composite specimens was fabricated using coir fiber with 30 mm, 40 mm and 50 mm lengths. They were formed by hand-lay up technique in vacuum bag.. The specimens of composite plate were tested for mechanical property according to ASTM D638. The mechanical property was assigned into the computational model and FEA computational program, ABAQUS, was applied for analytical process. Further study indicated that coir fiber is capable to use as composite material for helmet shell. The helmets with coir fiber provided higher crashworthiness capacity. This was verified by many key indicators such as the reductions of peak load and peak acceleration values and the improvement of the mean load. However, the value of HIC were not significantly changed compared to commercial helmet in some cases and this should be further investigated. Furthermore, it was also founded that the length of coir fiber affects to the crashworthiness capacity of helmet under impact significantly. The helmets with fiber length 30 mm reduced peak load by 40.68% and 30.42%, and reduced peak acceleration by 42.54% and 30.21%, and reduced HIC by 10.06% and 11.83% compared to helmets with fiber length of 40 and 50 mm, respectively. Therefore, it may be concluded that the coir fiber of 30 mm can significantly improve the crashworthiness capacity of helmet shell.