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Characterization of
CNT properties using space-frame structure
Muhammad Arif and Jacob Muthu |
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Vol. 13 (2018), No. 4, 443–461
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Abstract |
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We studied the elastic properties of different carbon nanotubes (CNTs), i.e., pristine and defective single-wall (SWCNTs), double-wall (DWCNTs), and multiwall (MWCNTs) for zigzag and armchair configurations. CNTs atomic geometry was replicated with an equivalent space frame structure (SFS). Coordinates definition of SFS of CNTs was developed in MATLAB code and transferred to the finite element analysis (FEA) software ANSYS. The basic entity of SFS, the C-C chemical bond, was designed as a circular beam with orthotropic properties. The properties were determined by linking the energy equation of molecular mechanics to structural mechanics along with a parametric study. The van der Waals forces between intershells of DWCNTs and MWCNTs were modeled as linear elastic springs in a simplified way. The simplified model avoided the problems due to the nonlinear behavior of van der Waals forces and improved the performance of the FEA software. The effect of chirality, vacancy defects, different diameters, and number of walls on the elastic properties of CNTs were calculated, tabulated, and compared with each other. The result of the proposed SFS model with orthotropic properties was compared with other’s results. The space frame structure (SFS) model is found to be better than the equivalent shell model as the defects can be placed at exact locations and a more realistic behavior can be predicted. The SFS models can developed with any type of defect, any number of walls, van der Waals force interactions, and agglomerated forms with variable geometries. These models could be directly embedded in the matrix with a designable interface region to predict tensile and torsional properties of future nanocomposites. |
Keywords
carbon nanotubes, numerical modeling, continuum Mechanics,
finite element analysis, properties
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Milestones
Received: 30 November 2017
Revised: 8 March 2018
Accepted: 28 May 2018
Published: 13 December 2018
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Authors |
| Muhammad Arif | |
| School of Mechanical, Industrial and
Aeronautical Engineering University of the Witwatersrand Johannesburg South Africa |
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| Jacob Muthu | |
| Department of Civil, Geological, and
Environmental Engineering University of Saskatchewan Saskatoon Canada |
School of Mechanical, Industrial and
Aeronautical Engineering University of the Witwatersrand Johannesburg South Africa |
