Wrinkling of Graphene Sheet under Constrained Extension via Atomistic and Continuum Mechanics Simulations

Abstract

Graphene is the thinnest materials in the universe with the thickness of one carbon atom only. Here, we demonstrate the wrinkling behaviors of graphene sheets under constrained extension using both atomistic simulation and continuum mechanics method. Due to the constraint of the loading edges, the deformation in the graphene is not uni-axial extension. Compression stress perpendicular to the extension direction occurs in the middle region, and this local compression results in the wrinkling pattern, as illustrated by our molecular dynamics simulations. We find that the slenderness ratio plays a very important role in the wrinkling pattern. When the ratio exceeds a critical value, the parallel lines break at the middle and separate to two parts on the left and right region. This has also been explained by deformation analysis using the finite element method. The wavelengths and magnitudes of the wrinkling are dependent on the mechanical properties of graphene and the applied extension strain. Our results can be of great significance to control the wrinkling pattern of suspended graphene, and further to design nano-meter sized mechanical sensors.