A New Multi-Physics Molecular Dynamics Finite Element Method for designing graphene based nano-structures

A new Multi-Physics Molecular Dynamics Finite Element Method (MDFEM) is proposed, which exactly embeds the equilibrium equations of Molecular Dynamics (MD) within the computationally more favourable Finite Element Method (FEM). This MDFEM can readily implement any force field because constitutive relations are explicitly uncoupled from the geometrical element topologies. Different force fields, including bond-order reactive and fluctuating charge-dipole potentials, are implemented exactly in a commercial FE code, with both explicit and implicit dynamic formulations. The latter allows for larger length and time scales as well as eigenvalue analyses. The MDFEM is shown to be equivalent to MD, but at a considerably reduced computational cost. Results and applications include conformational and parametric topology studies of Pillared Graphene Structures, the analyses of brittle fracture in defective Carbon Nanotubes, electric field induced vibrations and electron-emissions in CNT, electric charge distribution in graphene, and the concurrent multi-scale simulation with continuum mechanics and MD domains.