Predicting the Effective Mechanical Properties of Graphene Nanoplatelet-Carbon Fiber-Epoxy Hybrid Composites Using ReaxFF: A Multiscale Modeling

摘要

Numerous research efforts have been focused on developing lightweight epoxy-based composite materials that can rival expensive metal alloys in specific aerospace structural components. Due to their high-specific stiffness and strength and corrosion resistance, epoxy-graphene nanoplatelets (GNP) composite materials can be used as the matrix of carbon fiber-reinforced hybrid composites. This work provides a multiscale computational analysis to simulate the hybrid composite and predict its effective mechanical properties. The work-flow of this study involves two main sequential stages that can be specified towards acquiring the effective mechanical properties of the hybrid composite. Molecular dynamics (MD) simulations using large-scale atomic/molecular massively parallel simulator (LAMMPS) to create a nanoscale unit cell from EPON 862-DETDA epoxy and GNP was the first stage. The reactive force field (ReaxFF) was chosen to represent the atomic/molecular level interactions in these simulations. The interaction between aromatic rings in epoxy molecules and GNP was investigated in this study. It was found that such interactions can affect the spatial density distribution of the epoxy molecules at the GNP/epoxy interphase. The second stage involved a micromechanical analysis of the carbon fiber-reinforced hybrid composite using NASA's micromechanics analysis code based on the generalized method of cells (MAC/GMC). The effective mechanical properties of the hybrid composite were predicted at different volume fractions of GNP in the composite matrix.