Influence of Graphene Oxide Mass Fraction on the Mechanical Properties of Polyamide-Based 6,6 Composites

In this paper, a molecular dynamics model and a finite element model of graphene oxide-reinforced composites were developed, and the effects of mass fraction of graphene oxide (GO) on the mechanical properties of GO/PA66 composites were analyzed. The molecular dynamics model was randomly distributed in the finite element model to achieve cross-scale calculations from nanometer to micron. The effect of the molecular dynamics model size on the tensile mechanical properties of the composites was evaluated, and it was found that the elastic modulus initially increased and then decreased with the increase in model size. The study revealed that GO is surrounded by numerous hydrogen bonds, and these enhance the mechanical performance of the composites. Subsequently, a finite element model of the GO-reinforced composites was developed. The mechanical properties obtained from the size-optimized model of the molecular dynamics simulation were randomly specified within the finite element model to create a fine-scale model. And the calculations showed that GO enhances the mechanical properties of the composite by altering the stress transfer paths in the composite and taking up a larger amount of stress.