Abstract:

The destruction process of armchair single- layered graphene sheets with central crack was investigatedvia the molecular dynamics simulation based on Tersoff potential function,and the corresponding stress- straincurves as well as the failure mode were obtained.Then,the effects of crack length,strain rate and temperature onthe tensile mechanical properties of armchair graphene sheets with central crack were explored.It is found that (1)the fracture strength,the fracture strain and the crack initiation stress all decrease with the increase of crack lengthand temperature; (2) with the increase of strain rate,the fracture strength and strain,the crack initiation stressand the average cracking speed increase accordingly; (3) the fracture begins around the central crack and exhibitsdifferent deformation mechanisms with the variation of crack length,strain rate and temperature; and (4) C-Cbonds break in both the center and the edge of graphene sheets at higher strain rates.

Key words: graphene sheet, central crack, molecular dynamics, crack length, strain rate, temperature