Synergistic influence of MWCNTs/RGO on low-velocity impact response and mechanical properties of carbon fiber/epoxy composite

Nanoparticles can be used to enhance and improve the mechanical properties and low-velocity impact response of carbon fiber-reinforced polymer (CFRP) composites both simultaneously and individually. Also, the synergistic influence of two nanoparticles can be improved the mechanical properties and low-velocity impact response of CFRP composites. In this paper, the effects of reduced graphene oxide (RGO) and multi-walled carbon nanotubes (MWCNTs) on the mechanical properties, low-velocity impact response and damage area of epoxy/fiber carbon composites are investigated both simultaneously and individually. Composite specimens are fabricated with 0.4 weight percentages (wt.%) of RGO, 0.06 wt.% of MWCNTs individually, and a combination of RGO and MWCNTs with 0.6 and 0.06 wt.%, respectively. For comparison of the results, the neat epoxy specimens are fabricated and also tested. Direct homogenization technique is applied for preparation of nanocomposite mixture and then each layer of carbon fiber reinforced nanocomposite is fabricated using a hand lay-up process. Tensile modulus, tensile strength, variations of load, displacement, velocity, and absorbed energy of specimens versus time are obtained. For specimens with MWCNTs/RGO tensile modulus and tensile strength increased by about 21.30% and 17.12%, respectively, and the load peak increased by 15.15% at 1 J, 13.35% at 2 J, 39.62% at 3 J, and 39.62% at 3 J. It is concluded that the synergistic influence of MWCNTs and RGO on the results is more significant and has a higher effect on the impact responses. After the impact tests, Optical microscopy and SEM method are used to analyze fracture surfaces.