Effect of graphene nanoplatelets on the impact response of a carbon fibre reinforced composite

In the present paper, experimental investigations were conducted to assess the effect of nanomodification on the impact behaviours of hybrid composite plates. Graphene nanoplatelets (GNPs) of two different sizes, 5 and 30 µm, were used to modify a composite material made with 64 wt.% of unidirectional fibres and a low-viscosity epoxy resin. The effect of the nanomodification with 30 µm GNPs was also studied on composite plates prepared with a higher viscosity resin. Three laminate thicknesses (4, 8, and 16 layers) were tested with a standard drop dart testing technique. The peak forces as well as the absorbed energy and the fracture surfaces, observed with a Scanning Electron Microscope (SEM), were compared. Experimental results showed that nano-modification with 5 µm particles had a detrimental effect on both the peak forces and the absorbed energy, whereas the addition of 30 µm GNPs increased the absorbed energy, especially for a laminate thickness of 16 layers. Overall, the experimental results demonstrated that the size of graphene nanoparticles has a significant effect on the impact response of composite laminates.