Strain Energy Release Rate and Mode-I Delamination Growth in Carbon-Graphene/Epoxy Hybrid Nanocomposites

Abstract

The influence of graphene reinforcement in strain energy release rate (GIC) and Mode-I delamination growth in carbon-graphene/epoxy (CG-Ep) hybrid nanocomposites have been studied using the double cantilever beam(DCB) test. The specimens of carbon/epoxy (C-Ep) and CG-Epnanocomposites were manufactured using vacuum assisted manual lay-up method. DCB tests were conducted in a displacement controlled mode to achieve stable delamination growth under static loading. At the onset of delamination growth, the load (Pcr) and the total opening displacement (δcr) were recorded. The total compliance of the DCB specimen was obtained using, C=δ/P. Pcr and δcr are recorded as a function of the delamination length (a). Plots of critical loads and compliances as a function of the delamination size were used in computing GIC, the Mode-I critical strain energy release rate. The delaminated zone was studied through fractographic examinations and surface roughness measurement. The results show improved GIC of CG-Epnanocompositesin comparison to traditional C-Ep composites. The fractured surface of CG-Ep shows undulated surface with higher roughness which possibly contributed in crack deflection mechanisms.