Investigation of fracture and mechanical properties of monolayer C3N using molecular dynamic simulations

Molecular dynamics simulations are used to study the mechanical and fracture properties of C3N. The impact of initial crack orientation on the crack path is studied by applying tensile strain to C3N sheets containing initial cracks in the armchair and zigzag directions. The results show that the cracks grow by creating new surfaces in the zigzag direction. The capability of Griffith theory in prediction the fracture strength of C3N is studied. The molecular dynamic results indicate that Griffith theory cannot predict the fracture strength of C3N if the crack length is shorter than 9 nm. The notch effects on the fracture strength of C3N is studied and it is shown that notch effects are important in predicting the fracture strength of C3N. Using the Rivlin–Thomas method, the molecular dynamics simulations predict a critical energy release rate of 10.982 J/m2 for C3N. The impact of temperature and strain rate on Young’s modulus and fracture stress of C3N are studied. The results show that Young’s modulus is not sensitive to temperature but increase in the temperature leads to a reduction in the fracture stress. Young’s modulus and fracture stress are not sensitive to strain rate if the strain rate is less than 2 × 109 s−1.