Computational Nanomechanics

Nanomechanics is literally "the mechanics of/in nanoscale materials". The mechanics of nanomaterials may differ from that of their bulk counterparts the confinement of electrons originated from their extremely small sizes. For example, the elastic constants of materials in a undeformed configuration are not "constant" any more at nanoscale, but rather they changes by the size and shape of the materials. There are many subjects which exhibit unique or exceptional mechanical behaviors of materials in "the nano world". CAN is exploring this unrevealed world by using tools of computation.

• Fracture:
• Dislocation: Stress-drop
• Wave Propagation: Wave Propagation Graphene monolayer/ Nanoplates
• Stability: Elastic instability

Computing Methods in Nanoscale

There are many good tools to mine precious germs in the nano worlds. Of course, they are not always good, and they have advantages and disadvantages based on what we want to know. Here we list the representative computational methods, which are currently utilized in the CAN Lab to investigate the nanomechanics. According to resolutions, they can be categorized into quantum - atomic - (meso) - continuum methods. In addition, ADMD is a specially developed method in order to explore the rare event systems, and Scale-Bridging is a hot topic to merge more than two different resolution into a single computational framework.

• Quantum Simulations (DFT)
• Atomic Simulations (MD)
• Continuum Simulations (FEM)
• Bridging Scales
• Rare Event Calculations (ADMD)

Nanomaterials

All materials are able to be nanomaterials as long as their sizes (at least one dimension) become nanoscale. By virtue of the nature herself, many materials reveals exceptional or extraordinary characteristics compared to their bulk counterparts, when their size reaches to nanometer scale. Among them are fullerenes and graphene which gave nobel prizes to Smalley and Geim, respectively. CAN is now mainly working on the mechanics of graphene, metal nanowire, nanoplates, and free surfaces.

• Graphene: Edge Effects on the Intrinsic Energy Dissipation in Graphene Nanoresonators/Multilayer and Clamping Effects on Q-Loss
• Nanowire: Enhancing Nanowire Q through Mechanical Strain
• Nanoplate: Unusual Poisson's Ratio in Metal Nanoplate
• Nitinol(NiTi): DFT study of nitinol for shape-memory alloys
• Silicate: Cyclability of Transition Metal Silicates

Supercomputers & Supercomputing

What are necessary physical weapons in the battlefield of computational nanomechanics Only one thing we need is computer. We call it (literally) CAN! What is the best physical weapon here? That is supercomputer. CAN is one of heavy users of UNIST Supercomputing Center. CAN has a great interest in the supercomputer and supercomputing (how to use supercomputer).

• UNIST Supercomputing Censter (USC)
• National Supercomputing Challenge in Korea
• International Student Challenge (ISC & ASC)
• National Education in Supercomputing
• National Supercomputing Challenge in KOREA
• UNIST HPC School

Validity of the Continuum (Solid) Mechanics Theory in nanoscale

CAN has been studying whether famous solid mechanics theories, such as Hill's instability, Betti's reciprocity, Lamb wave, etc., can be adopted to nanoscale materials. And, CAN is now trying to figure out how much the behaviors of nanomaterials differ from their corresponding continuous materials based on these theories. CAN will update these recent research results soon.