COMPARATIVE STUDY OF MOLECULAR DYNAMICS AND PHASE FIELD MODELLING FOR BRITTLE FRACTURE

Abstract

In this study, molecular dynamics fracture simulation of a brittle single layer graphene sheet is performed to give us the parameters needed to perform phase field fracture modeling. Molecular dynamics simulation encompasses the physical nature of the fracture and is discrete while phase field is a continuum phenomenological method of performing these simulations. By deriving parameters for phase field simulation through atomistic simulation an attempt has been made to establish a link between different scale models and to establish a correspondence in predicting crack path. Using the parameters obtained through molecular dynamics accurate path prediction and branching of cracks were observed through phase field modeling when compared to physics-based molecular dynamics. The force at which fracture occurred was found to be comparable, despite stiffness showing some difference between two models. The relation between the two models can be established where the continuum model retains the essence of atomic details. This would open up a path for multiscale simulations which are much more accurate and reliable.