Investigation of Mechanical Properties of Carbon Fiber/Graphene Nanoplatelet/Epoxy Hybrid Nanocomposites

Abstract

Graphene nanoplatelets (GNPs) inherently possess excellent mechanical properties, and this may be employed in the enhancement of the mechanical properties of carbon fiber (CF)/epoxy composites by using them as an additional reinforcing agent. The present work puts forward the investigation of the mechanical properties of CF/GNP/epoxy hybrid nanocomposites. The mechanical properties have been determined for different volume fractions $\left( {V_{F} } \right)$ of CF and GNP by using the modified Halpin–Tsai model and rule of mixture. It was observed that the mechanical properties such as longitudinal Young’s modulus, transverse Young’s modulus, in-plane shear modulus and out-of-plane shear modulus of the CF/GNP/epoxy hybrid nanocomposites increased with increase in $V_{F}$ of GNP in the CF/epoxy composite. On the contrary, the major and minor Poisson’s ratio decreased with increase in $V_{F}$ of GNP in the CF/GNP-epoxy hybrid nanocomposites. However, the minor Poisson’s ratio increases and reaches its maximum value, then decreases with the increase in $V_{F}$ of CF. The analytical results show that for CF/epoxy composite having 45% $V_{F}$ of CF, the longitudinal Young’s modulus, transverse Young’s, in-plane shear modulus and out-of-plane shear modulus increased by 36.79%, 686.84%, 994.53% and 687.18%, respectively, due to adding 9% $V_{F}$ of GNP. However, the major and minor Poisson’s ratio of CF/epoxy composites decreased by 2.75% and 14.47%, respectively for same $V_{F}$ of GNP. Thus, inclusion of GNP significantly improves most of the mechanical properties of the nanocomposites creating a superior material for structural applications.