Modeling for predicting strength of carbon nanostructures

We have developed a computational scheme to predict stiffness and strength of carbon nanostructures under various loading modes. The prediction method is based on combined molecular mechanics and molecular dynamics simulations to approach a global energy minimum at a given loading level with a preset temperature tolerance of 10−6K. We have applied the present method to various carbon nanostructures including carbon nanotubes (CNTs), graphene, CNT with defects, a CNT-graphene junction and pillared graphene nanostructures. For all cases, we have identified the maximum stress and strain at failure of these carbon nanostructures as well as their critical failure modes, and discussed mechanisms that lead to their catastrophic failure.