▎ 摘　　要

We study the mechanical behavior and fracture of graphene nanomeshes (GNMs) consisting of hexagonal lattices of unpassivated circular pores based on molecular-dynamics simulations of uniaxial tensile deformation tests. We analyze the GNMs' mechanical response as a function of their porosity for porosities up to 80%. We find that the fracture strain exhibits a minimum at a porosity similar to 15%, which marks the onset of a transition in the mechanical behavior of the nanomeshes; beyond this critical porosity, the GNM ductility increases and the toughness remains practically constant with increasing porosity. The mechanism of crack initiation and propagation is characterized in both cases of mechanical response. (C) 2015 AIP Publishing LLC.