Besides edge effects, graphene nanoresonators are expected to lose energy through interlayer friction effects, and the quality of attachment through van der Waal’s forces to the underlying (model silicon) substrate. We have quantified these losses as compared to an ideal graphene monolayer, as seen below. The key result is that, if intrinsic interlayer friction and […]
Interestingly, the study also found that the free edges of the graphene sheet often had the largest vibrational amplitudes during resonance. To verify this, finite element simulations of the graphene sheet were performed; by introducing non-uniform stresses in the suspended graphene sheet through application of both an in-plane stretch and an in-plane rotation, the authors […]
One of interesting topics in computational nanomechanics is rare event system, where a special event occurs very rarely, however, it is very important. Conven-tional MD is too wasteful to track these phenomena. Typical examples of rare event systems are atomic diffusion, structural changes of molecules and protein folding/unfolding. Here, the reaction pathways and activation energy […]
Each method (resolution) has strong and weak points. To maximize the strong points and to overcome limitations, scale bridging methods (multiscale) are widely studied. We are now developing an efficient multiscale method for shape memory alloys and secondary battery materials under the cooperation with other research groups: SNU, SKKU, Yonsei, Sogang, Kyunghee Universities.
Finite Element Method (FEM) is one of most successful computational schemes in various engineering fields, including structural, vibrational, heat transfer, electro-magnetic, diffusion analyses and even fluid dynamics. Especially, FEM is a powerful tool to obtain the stress-strain-deformation field of solids under loading. The stress and thermal analyses of a center pillar mold for automobile are […]
Molecular Dynamic (MD) calculations are suitable to describe the discrete nature of nanoscale materials. Classical MD usually solves atomic motions governed by the Newton’s second law, where the interaction between atoms or particles is described by empirical potentials. The accuracy and efficiency of MD calculations are strongly dependent on the empirical potentials employed. As an […]
Density Functional Theory (DFT) calculations are one of the most accurate and expensive simulations to investigate nanomaterials. Electronic properties, such as band structure of materials are widely studied by DFT. The band structure and its change due to applied strain of an MoS2 monolayer are conducted as an example. An MoS2 monolayer show direct […]