Comprehensive 3-D homogenization approach for predicting mechanical properties and creep behavior of polymer nanocomposites reinforced with graphene nanoplatelets

The aim of this study is to provide a comprehensive 3-D homogenization approach based on the high-fidelity generalized method of cells method to predict the mechanical properties and creep behavior of polymer nanocomposite reinforced with graphene nanoplatelets. Several fundamental experimental aspects including the volume fraction, size, and random orientation of graphene nanoplatelets, the interphase region, and the aggregation state of nanofillers of graphene are taken into account. The present study introduces two novel perspectives. At first, the aggregation of graphene nanoplatelets is formulated as dependent on volume fraction. Then the size of graphene is formulated as an important factor affecting the interphase region and the mechanical properties of polymer nanocomposite. Micromechanical tests conducted using the proposed method illustrate the good agreement with experimental data. The results of the parametric study on different experimental aspects revealed important findings. (i) For a specific value of graphene nanoplatelet volume fraction, the mechanical properties of polymer nanocomposite are at the best state. By increasing the graphene content beyond the specified graphene content value, the effective properties of graphene are decreased. (ii) The size of graphene nanoplatelets and the characteristics of the graphene/polymer interphase region have a direct effect on the properties of the nanocomposite.