Investigation on Short Carbon Fibre-Filled NBR Composites for Fabrication of Low-Frequency Vibration Isolator

Abstract

Vibrations generated by onboard machinery in marine vessels can result in several adverse consequences, including reduced equipment lifespan, interference with communication systems, and compromised stealth capabilities in strategic applications. Passive anti-vibration mounts are a viable solution to mitigate these issues by isolating equipment operating above a specified frequency. This study investigates the material properties of short carbon fibre-filled nitrile rubber (NBR) compounds and their effectiveness in vibration isolation for low-frequency applications. The materials were characterized for their physico-mechanical properties using various instrumental techniques, followed by a comparative analysis. Damping properties were assessed through Dynamic Mechanical Analysis (DMA) and the time-temperature superposition method. Among the series of compositions, NBR with 2 parts per hundred rubber (2 phr) fibre loading exhibited optimal performance for low-frequency applications, demonstrating superior tear strength and the lowest compression set. The tan δ value with broad curve for the
2 phr fibre composition ratified with hysteresis values of mount made out of this also. Mounts fabricated with this composition exhibited a resonance frequency of 15 Hz under a 190 kg load. This study encompasses the design of rubber compounds and the characterization of materials in both raw and mounted forms.