Effective Elastic Properties And Mechanical Behavior Of Single Layer Graphene Sheets

Single layer graphene sheets (SLGSs) is a honeycomb-like layer plane comprised of carbon atoms, its thickness is only one carbon atom. It is important, because fullerenes and carbon nanotubes are formed by SLGSs's curling. Previously, people think that SLGSs cannot exist in normal temperature. But in 2004, Novoselov et al successfully made SLGSs, since then people began to concern about this two-dimensional single-layer graphite material. SLGSs is not only the thinnest material, but also have a very different character. Theoretical and experimental studies demonstrated that SLGSs had very high strength, stiffness and toughness as well as the specific electrical properties. So it had a wide application in the area of nano-mechanics, nano-composite materials, etc.In this paper, the molecular dynamics (MD) method and non-local elasticity theory is used to investigate the mechanical properties of SLGSs.In the MD simulations, the SLGSs is considered as a congeries of individual atoms, the movement equations are established for every atom, and the deformation behavior of SLGSs can be determined by the trajectories of each atom. This paper deals with the deformation of SLGSs under different mechanical loads by using MD methods. The simple loads considered are tension, shearing and bending. We focused on the deformation of different SLGSs under different temperatures.Using the continuum mechanics of thin plate under lager deflection, we can uniquely get the young's modulus and the effective thickness. Non-local elasticity theory can account for small-scale effect of nano structure. In this paper, compared the results (deflection and vibration frequency) of molecular dynamics with non-local elasticity theory, we can got a small scale parameter. Therefore, non-local elasticity theory can be used to solve the problem of nano-structure. This research is helpful in the field of the fiber composite nanometer thin films and nano-machines.