Improvement by Nanofibers of Load Transfer in Carbon Fiber Reinforced Composites

Abstract

This paper focuses on the load transfer improvement caused by nanofibers (NF) in carbon fiber reinforced composites. Load transfer is defined as the ability to transfer the mechanical loading between two adjacent fibers through the surrounding matrix. NF action is explored with a finite element model representing two carbon fibers separated by a layer of a NF reinforced matrix. It appears that the role of the NF network is to strengthen the matrix by increasing matrix shear rigidity, and thus to improve the load transfer between the carbon fibers. NF network morphology, defined by NF orientation, NF spatial distribution or NF diameter, governs the NF network efficiency.

Multi-Scale Carbon (Micro/Nano) Fiber Reinforcement of Polyetheretherketone Using High Shear Melt-Processing

“…All concentrations of the CNF-PEEK composites are more ductile than 20CF-2.5CNF-PEEK, as shown in Figure 6b. This supports the observation that CNFs likely act as bridges throughout the matrix due to good interfacial bonding between the fibers and the matrix, as well as kinks on the CNF surface impeding fiber pullout, and that CFs provide the main load bearing capability [24]. The 20CF-2.5CNF-PEEK multi-scale composite combines the stiffening, reinforcing effect of the CF and the enhanced ductility effect of the CNF, as shown in the stress-strain curves in Figure 7a.…”

“…% CNF to 20CF-PEEK enhances ductility, while maintaining similar modulus and strength values as 20CF-PEEK, as seen in Figure 5b. This is likely due to CNFs acting as bridges throughout the matrix, thereby increasing the composite's shear rigidity and improving the load transfer at higher strains [24]. Figure 5b.…”

“…Figure 5b. This is likely due to CNFs acting as bridges throughout the matrix, thereby increasing the composite's shear rigidity and improving the load transfer at higher strains [24]. The tensile mechanical properties of the CNF-PEEK and 20CF-2.5CNF-PEEK composites, along with the corresponding representative stress-strain curves, are found in Figure 6.…”