Multiscale modeling of graphene- and nanotube-based reinforced polymer nanocomposites

► A hierarchical MD/FEM multiscale model of nanocomposites is developed. ► At low nanofiller content, graphene layers perform significantly better than CNTs. ► Ripples in the graphene layers reduce the Young modulus of nanocomposites. ► The elastic moduli is considerably affected by the shear of graphene layers.