Effect of loading direction and defects on the strength and fracture behavior of biphenylene based graphene monolayer

Using molecular dynamics (MD) simulations, we investigate the strength and fracture behavior of biphenylene based graphene (BG) monolayer subjected to uniaxial tensile deformation along the x- and y-directions. AIREBO potential is used for modeling the C-C atom interactions, and the simulations are carried out under isothermal conditions at a temperature of 300 K and strain rate of 10(10) s(-1) using NVT ensemble. Defects such as cracks and voids are introduced in the monolayer to study their influence on the strength and mechanism of crack propagation. From the results, we conclude that monolayer strength and fracture behavior are dependent on the loading direction. Fracture in the monolayer is observed only when loaded along the x-direction and has comparatively lower strength. Further, the crack propagates by bond breaking along the four-membered rings in the biphenylene unit. As anticipated, the strength of the monolayer decreases in the presence of defects and the crack speed is estimated to be 7 x 10(3) m/s. (C) 2017 Elsevier B.V. All rights reserved.