The Computational Study of Initial Pressure Effects on Mechanical Performance of Defective Graphene Nano-sheet: Molecular Dynamics Simulation

Graphene exhibits exceptional mechanical performance due to its promising atomic structure. It is a 2D sample constructed of a single layer of C atoms stabilized in a hexagonal structure. In this paper introduced the structural and mechanical evolution of defective graphene nano-sheets at various initial pressures by using molecular dynamics (MD) simulations. Initial pressure significantly influences the mechanical behavior of defective graphene nano-sheets which don’t analyzed in previous researches. This type of simulation done in two main phases as equilibrium phase (for 1 ns) and mechanical test phase by using the Tersoff force field. The equilibrium phase of pristine sample detected by temperature and total energy convergence to 300 K and -28736.029 eV, respectively. Previously, the effect of pressure on structural/mechanical behavior of defective graphene-based structures doesn’t reported by atomic precision. This study clarifies this parameter influence in designed nano-sheets in mechanical cases which should be supposed in various applications of them. For this, the equilibrium phase of samples predicted with temperature and total energy calculations. Next, the mechanical performance of equilibrated systems described by US and YM calculations. The main limitation in using of defective nano-sheets is structural/thermodynamics stability of them in actual cases. MD simulations predicted the US and YM of samples increased to 86.41 GPa and 394.28 GPa (respectively) by initial pressure increasing to 3 bar. Physically, this mechanical evolution arises from attraction interaction enlarging between various atoms in defective graphene samples. But more pressure enlarging caused the interatomic distance decreased more and repulsive force created inside them. This process caused the mechanical strength decreased to lower level. This mechanical evolution of defected graphene sample should be supposed in actual applications of them.