Experimental investigation on vibration characteristics and damping factor of coir fiber reinforced polyester composite material
Authors :- Nikhil, K.V., Ramasubramanian, S., Gudimetla, A., Dikshit M.K. et al.
Publication :- Discover Applied Sciences, Springer (2025)
This research aimed to investigate the composite material composed of polyester with randomly oriented short coir fibers with a length of 10 mm and varying weight percentages from 5 to 20%. The composite material was fabricated by the hand layup method. The tensile strength, flexural strength, hardness, impact strength, free vibration analysis, and damping characteristics were studied; the SEM images were used to analyze the fractured surface of the composite specimens. The current empirical study identified a conspicuous association between the gradual escalation in fiber content for the natural frequency and the damping attributes of the composite material. The test results showed that the composite with 15% coir fibers worked best for several studies examining characteristics over a wide range of temperatures and frequencies. Coir-based composite material yields a natural frequency of 61,862 Hz and a maximum damping ratio (ζ) of 0.29592, indicating enhanced rigidity and vibration absorption capabilities. The damping factor (tan δ) reached a notably low value of 0.360 at a 10 Hz frequency with 15 wt.% fiber content, demonstrating improved energy dissipation. The results show that polyester composites containing 15% wt.% coir fibers have the best mechanical and damping properties, making them a sustainable choice for industrial uses that need to reduce vibrations.