▎ 摘　　要

In this research, by a combined molecular dynamics-micromechanics method the stiffness of graphene nanoplatelet/epoxy nanocomposites is predicted. It is assumed that graphene sheets are randomly oriented in the polymer matrix. First, the stiffness of a multilayered graphene nanoplatelet was achieved using the molecular dynamics (MD). Then, results obtained by the molecular dynamics were used by the Mori-Tanaka (MT) and the Halpin-Tsai (HT) micromechanics models to predict nanocomposite stiffness. These combined models are called the MD-MT and MD-HT models, respectively. The results obtained show that the MD-MT model is more compatible with the result of experiments at low filler contents (<0.25 wt.%) in comparison with the MD-HT model. While, the MD-HT model is more reliable at high filler contents (>0.25 wt.%). Mechanical properties of graphene nanoplatelet/epoxy nanocomposites with several contents of graphene nanoplatelet, i.e. 0.05, 0.1, 0.25, 0.5 and 1 wt.% were considered and the optimum graphene content was obtained. (C) 2014 Elsevier B.V. All rights reserved.