▎ 摘　　要

A semi-continuum mechanical model has been developed for analyzing the wrinkling of graphene sheet supported by a soft substrate. An energy based method is adopted, in which the elastic energies of graphene sheet and substrate as well as the interfacial van der Waals energy are considered. The graphene sheet and substrate are modeled by continuum mechanical method. In order to estimate the interfacial interaction directly, molecular models of graphene sheet and Polydimethylsiloxane (PDMS) substrate are combined with the continuum models. Graphene wrinkling due to the stretch-then-release process has been examined. The numerical results reveal that substrate deformation in the thickness direction leads to the initial wrinkled morphology of graphene sheet, which is further enhanced by the nonuniform interfacial van der Waals interaction. Upon releasing the substrate, the wrinkle wavelength of graphene sheet with initial wrinkled morphology decreases linearly with the released strain. (C) 2017 Elsevier B.V. All rights reserved.