Investigation to appraise the vibration and damping characteristics of coir fibre reinforced polypropylene composites

Abstract

Natural fibre composites having industrial attraction due to their advantage with density, cost, specific mechanical properties etc. compared to synthetic fibre. Exploring the dynamic properties still found inferior at literature which motivated the reported work. Randomly oriented Coir fibre reinforced Polypropylene (PP) composites are fabricated through injection process separately for different fibre weight fraction (varied from 0 to 30% in steps of 10%). Dynamic properties like natural frequency and damping of produced composites were studied through impulse excitation technique. Influence of fibre loading on vibration characteristics was studied. Fundamental natural frequencies of 30 wt.% coir fibre composite were higher than the Pure PP, 10 wt.% fibre and 20 wt % fibre reinforced composites. This happened for all modes of vibration because of high stiffness of fibres. The weight fraction of Coir-PP composites is affected the damping ratio as well. Increase in weight fraction of fibre decreased the damping ratio. The high resin content leads to higher damping, so with the higher weight fraction of fibre reinforcement in composites which least the resin content and cause a decrease in damping. This material suit for applications where the attenuation of vibrations is desirable, for example, secondary structural components in automotive.