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

• Published in: Materials chemistry and physics 2017-12, Vol.202, p.127-135
• Main Authors: Yedla, Natraj, Gupta, Pradeep, Ng, Teng Yong, Geethalakshmi, K.R.
• Format: Article
• Language: English
• Subjects: Biphenylene graphene; Computer simulation; Crack and void defects; Crack propagation; Defects; Deformation mechanisms; Fracture behavior; Fracture mechanics; Fracture toughness; Graphene; Hydrocarbons; Molecular dynamics; Molecular dynamics simulation; Molecular structure; Monolayers; Strain rate; Strength; Studies; Tensile deformation; Tensile strength
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2017.09.016

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 1010 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 × 103 m/s. [Display omitted] •Loading direction effect the strength and fracture behavior.•Linear defect reduces strength more than the circular defect.•The estimated crack speeds are in the range of 5–7 km/s.