A computational molecular dynamic model involving multilayer graphene nanoplatelets in epoxy composite was developed in order to characterize its elastic behavior when subjected to thermo-mechanical loadings. In this investigation, the approach for constructing the molecular structure of graphene/epoxy composite using Optimized Potential Liquid Simulation (OPLS) force field is documented. Also, the cross-linking and the method for equilibrating the systems are defined. The techniques used for evaluating the models under different loading conditions are given. The predicted results are made available for the user of composite materials.