Experimental investigation on flexural fatigue strength of graphene oxide modified E-glass epoxy composite beam

Many studies are currently being performed on the complex issue of fatigue of reinforced composite materials. Graphene oxide (GO) is a strong contender for reinforcement, an atomically thin form of carbon with remarkable multifunctional qualities and a perfect surface for interacting with polymer matrices. This report investigates the effect of GO modified epoxy resin on the flexural fatigue life of a composite beam. First, two different weight concentrations of 0.25 and 0.50 % are dispersed by ultrasonication in epoxy resin and composite beams are prepared through a hand layup process. The microscopic analysis confirmed the uniform dispersion. The static bend test resulted in an increase in the flexural strength of the GO-incorporated beam by 33.3 % compared with that of the neat epoxy beam. Flexural fatigue tests were performed for different load levels, and damage evolution at every 4000th cycle was observed. It was noted that under 60 % loading, a significant change in damage initialization was observed between neat epoxy and 0.25 % GO. However, under a higher load level,
a negligible effect of crack initialization was observed in all types of beams.