Effect of atomistic modeling parameters on the simulation of fracture in graphene

Abstract

For a wide range of graphene applications, it is required to examine the fracture characteristics of single-layer graphene sheets. In this article, we study the effective parameters in fracture of graphene, concentrating on the impact of atomistic modeling on results that have not been adequately evaluated in previous studies. We considered two distinct models to simulate a uniaxial tensile test in molecular dynamics. By comparing these models, we explore the influence of various parameters on the results, particularly fracture strength and failure strain. We demonstrate that in pristine graphene sheets, failure depends entirely on simulation modeling. The two main factors that lead to these variations are loading patterns and boundary conditions. Based on the models, the obtained results are significantly different. Nevertheless, in pre-cracked graphene, parameters are strongly affected by the initial defect, especially the crack tip. To better understand the parameters affecting the simulation results, we investigate the dependence of the mechanical properties of defective graphene sheets on strain rate and crack tip area. This investigation helps to comprehend these parameters and clarifies some of the reasons for the discrepancies in the literature.