Damping Enhancement of Hybrid Nanocomposites Embedded With Engineered Carbon Nanopaper

Abstract

This paper presents a novel process to manufacture multifunctional and cost-effective hybrid nanocomposites through integrating engineered carbon nanofiber paper into traditional fiber reinforced composites to improve structural damping properties. In this study, carbon nanofibers are vapor grown carbon fibers, which are grown catalytically from gaseous hydrocarbons using metallic catalyst particles. Vapor grown carbon nanofibers are much less costly than single-walled and multi-walled carbon nanotubes. Carbon nanofibers were preformed as a nanopaper which had a porous structure with highly entangled carbon nanofibers and short glass fibers. The vacuum-assisted resin transfer molding (VARTM) process was used to fabricate the nanocomposites by using engineered carbon nanofiber paper as inter-layer or surface layer of traditional composite laminates. To characterize the structural damping properties, the influence of frequency dependence was analyzed through the experiments conducted using the nanocomposite beams. It was found that there is up to 200-700% increase of the damping ratios at higher frequencies. In addition, experiments were also performed to study the interface characteristics between the carbon nanofiber paper and the laminate ply. The study showed a complete penetration of the resin through the carbon nanofiber paper. It was found that the connectivities between carbon nanofibers and short glass fibers within the carbon nanofiber paper were responsible for the significant energy dissipation in the hybrid nanocomposites during the structural vibration applications. The research results confirm the possible advantage of using engineered carbon nanofiber for damping augmentation.