research

Dear Colleagues,

Here is our recently published article on Symmetry-adapted real-space density functional theory for large nanotubes and bending deformations of thin sheets

Title: Symmetry-adapted real-space density functional theory for cylindrical geometries: Application to large group-IV nanotubes

 Authors: Swarnava Ghosh, Amartya S. Banerjee, Phanish Suryanarayana*

Concise summary

Dear Colleagues

I would like to share with you our recent work published on Journal of the Mechanics and Physics of Solids.

Abstract

In this book chapter we discuss some applications of algebraic topology in elasticity. This includes the necessary and sufficient compatibility equations of nonlinear elasticity for non-simply-connected bodies when the ambient space is Euclidean. Algebraic topology is the natural tool to understand the topological obstructions to compatibility for both the deformation gradient F and the right Cauchy-Green strain C. We will investigate the relevance of homology, cohomology, and homotopy groups in elasticity.

https://aip.scitation.org/doi/10.1063/1.5115282

Abstract

Dear colleagues, I'd like to share our recent work on blister testing of multilayer 2D materials that gives a direct measurement of Young's modulus and bending rigidity of a multilayer (~10-70 layers). Materials involved include graphene, MoS2, and hBN.

You may access the pdf through Phys. Rev. Lett. 123, 116101 or Researchgate. 

Dental implants are increasingly being placed for edentulous patients worldwide. While the clinical aspects of the implants are extensively investigated, engineering considerations of the implant as a functional structure subjected to ill-defined boundary conditions are less considered. A recent trend is to consider all ceramic implants as an alternative to the classical titanium-based implants.

Dear Colleague,

In the last two years, we published six papers on uniaxial deformation of tungsten nanopillars/nanowires/nanotubes using atomistic and coarse-grained atomistic simulations:

We combine experiment and finite element simulation and come up with a design of a mechanical metamaterial which demonstrates snap-back induced hysteresis and energy dissipation. The resultant is an elastic system that can be used reversibly for many times. The underlying mechanism of existence of hysteresis and the physics of snap-back induced elastic instability is unveiled. Our results open an avenue for design and implementation of recoverable energy dissipation devices by harnessing mechanical instability.

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A new family of mixed finite element methods --- compatible-strain mixed finite element methods (CSFEMs) --- are introduced for three-dimensional compressible and incompressible nonlinear elasticity. A Hu-Washizu-type functional is extremized in order to obtain a mixed formulation for nonlinear elasticity. The independent fields of the mixed formulations are the displacement, the displacement gradient, and the first Piola-Kirchhoff stress. A pressure-like field is also introduced in the case of incompressible elasticity.