Mechanical properties of graphene based nanocomposites incorporating a hybrid interphase

The elastic mechanical properties of graphene monolayer based nanocomposites considering a hybrid interphase region between reinforcement and matrix is being investigated via a multi-scale finite element approach. At the first level analysis, the proposed method uses atomistic representation of graphene to extract its elastic mechanical behavior. The output is then utilized on the second level analysis where a representative volume element (RVE) of the nanocomposite is under consideration. The RVE is considered as a three phase composite structure subjected to small strains. The reinforcing phase, i.e. graphene, is modeled in molecular detail via spring based line elements while the reinforced phase, i.e. epoxy, is modeled using continuum mechanics assumptions via the use of solid finite elements. Finally, the third and intermediate phase known as interphase is approached using solid finite elements as well as a hybrid concept. According to this concept, it is considered that the region between the two constituent materials presents anisotropy which is dependent on the distance from graphene and bounded by the surrounding mechanical properties. The influence of imperfect bonding between components is also investigated by introducing an adhesion coefficient within the adopted interphase property equations.