Atomistic Simulation Study of Crack Tip Blunting and the Influence of Blunting Behavior on the Fracture Strength of A Single Layer Graphene Sheet

摘要

The consequence of this result on the fracture behavior of graphene, including the crack initiation, crack propagation, blunting, fracture strength and energy release rate is the main topic of this paper. We proposed three mechanisms by which crack growth can occur in such blunted regions and also performed simulations on three different specimens of graphene sheets to demonstrate elastic blunting. For the study of fracture strength of graphene with different crack tip radius, different crack initiation behaviors are revealed, and it is demonstrated that the blunting effect of tip edges plays an important role in the fracture crack initiation and propagation of graphene. The characterized crack tip radius from 1.642 to 2.843 Å is observed, which can be used to estimate the fracture strength due to blunting at crack tip. The results of this work are deemed to be of importance from the perspective of modeling the fracture behavior of graphene sheet and in predicting its ultimate failure, post-blunting in fracture mechanism.