Anisotropic vacancy-defect-induced fracture strength loss of graphene

Abstract

The mechanical strength of graphene is much larger than any other materials, but is orientation-dependent and can be significantly weakened by vacancy defects existing in the lattices. In this work, we investigated the orientational anisotropic effect on the fracture strength of vacancy-defective graphene using molecular dynamics simulations. The results show that the fracture strength of graphene at the orientation angle of 15° has the smallest sensitivity to vacancy defects due to the minimization of stress concentration in this direction. Although the fracture strength of defect-free graphene in the zigzag direction is larger than that in the armchair direction, the fracture strength in the zigzag direction is much more sensitive to the vacancy defects. This study is helpful not only for understanding the physical properties of defective graphene but also providing guidance for developing graphene-based materials or devices in engineering.