▎ 摘　　要

The fracture behavior of single layer graphene sheet (SLGS) has been a subject of intensive research in recent years. Understanding the fracture mechanism of graphene under low temperature conditions is crucial for engineering applications of graphene. In this paper, a molecular dynamics (MD) simulation is employed to assess the effect of temperature on fracture properties of SLGS. The evolution of atomically cleaving of graphene is also discussed. A finite area of SLGS is subject to uniaxial tensile load in zigzag direction under various environmental temperatures between 1K and 77K. The effects of temperature on fracture properties as well as cracked morphology of SLGS are investigated. While our simulated results of fracture strength of SLGS agree with reported datum, simulated cracks are nucleated spontaneously instead of artificially inserted. The findings presented herein would help understand the morphology of a single layer pristine graphene sheet subjected to crack propagation at ultralow temperature.