Morphologies of monolayer graphene under indentation

We employ a quasi-continuum method to characterize the deformation morphologies of monolayer graphene under indentation. The method involves casting the atomistic interaction potentials into the constitutive relations at the continuum level, thereby facilitating large-scale simulations with atomistic fidelity. Our simulations mapped out different morphological phases under indentation, depending on the indentation depth, the graphene-substrate adhesion strength and the graphene size. We carefully characterized the rippling phase and found that the wave number of the periodic rippling is dependent on the graphene-substrate adhesion strength and the graphene size, but not on the indentation depth. The simulation results provide new insights into the structural instability of graphene.