Single-walled carbon nanotube modelling based on one-and two-dimensional Cosserat continua

This research aims to study the mechanical properties of single-walled carbon nanotubes. In order to overcome the difficulties of spanning multi-scales from atomistic field to macroscopic space, the Cauchy-Born rule is applied to link the deformation of atom lattice vectors at the atomic level with...

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Bibliographic Details
Main Author: Zhang, Yu
Format: Thesis (University of Nottingham only)
Language:English
Published: 2011
Online Access:https://eprints.nottingham.ac.uk/12211/
Description
Summary:This research aims to study the mechanical properties of single-walled carbon nanotubes. In order to overcome the difficulties of spanning multi-scales from atomistic field to macroscopic space, the Cauchy-Born rule is applied to link the deformation of atom lattice vectors at the atomic level with the material deformation in a macro continuum level. Single-walled carbon nanotubes are modelled as Cosserat surfaces, and modified shell theory is adopted where a displacement field-independent rotation tensor is introduced, which describes the rotation of the inner structure of the surface, i.e. micro-rotation. Empirical interatomic potentials are applied so that stress fields and modulus fields can be computed by the derivations of potential forms from displacement fields and rotation fields. A finite element approach is implemented. Results of simulations for single-walled carbon nanotubes under stretching, bending, compression and torsion are presented. In addition, Young’s modulus and Poisson ratio for graphite sheet and critical buckling strains for single-walled carbon nanotubes are predicted in this research.