Fracture toughness of single layer boronitrene sheet using MD simulations

Abstract

In linear elastic fracture mechanics, the critical stress intensity factor (CSIF) is related to the surface energy calculated from the bond energy in the reference configuration. For nanomaterials, the difference between the thus computed CSIF and that found from other methods is attributed to lattice trapping. We show here that the energy release rate (and hence the CSIF) determined from the energy of bonds on the crack surface in the current configuration agrees with that estimated by the traditional methods employing the fracture stress and the initial crack length. We demonstrate this by using molecular dynamics simulations with the Tersoff potential by studying crack propagation in a pre-cracked monolayer boronitrene.