The Interfacial Cohesive Law of Composite for Carbon Nanotubes and Single Crystal Metals

2012 ◽  
Vol 557-559 ◽  
pp. 505-509
Author(s):  
Gao Feng Wei ◽  
Ting Ting Yan ◽  
Hong Fen Gao
Keyword(s):  
Carbon Nanotubes ◽  
Single Crystal ◽  
Van Der Waals ◽  
Van Der Waals Force ◽  
Single Wall Carbon Nanotubes ◽  
Cohesive Law ◽  
Crystal Lattices ◽  
Metal Atoms ◽  
Composite Interface ◽  
Analytical Expressions

In this paper the interfacial cohesive law of composite for single-wall carbon nanotubes (CNTs) and single crystal metal is characterized by van der Waals force, and the new interfacial cohesive law is established. The van der Waals force is sensitively related to the distance of atoms, therefore single crystal metal is delaminated according to the structure of crystal lattices that the metal atoms of same distance to CNTs are divided into one layer, and a series of parameters are obtained. The analytical expressions of the new cohesive law are useful to studying the composite interface between CNTs and single crystal metal, and can give the macro properties of the composites accurately.

Axial Buckling Behavior of Double-Wall Carbon Nanotubes by Finite Element Simulation

2012 ◽  
Vol 562-564 ◽  
pp. 339-342
Author(s):  
Li Jie Chen ◽  
Yi Fan Zhang ◽  
Qi Zhao
Keyword(s):  
Carbon Nanotubes ◽  
Finite Element ◽  
Aspect Ratio ◽  
Van Der Waals ◽  
Maximum Amplitude ◽  
Van Der Waals Force ◽  
Single Wall Carbon Nanotubes ◽  
Buckling Behavior ◽  
Element Simulation ◽  
Double Wall

With finite element (FE) simulation, we study the buckling behavior of double-wall carbon nanotubes (DWCNTs) under axial compression. In the FE models, linear beam elements and nonlinear spring elements are used to simulate the complex structures and the Van der Waals' force between non-bond atoms from different layers is considered by the Lennard-Jones potential function. The effect of aspect ratio of DWCNTs and double-atoms vacancy on the buckling modes and the critical buckling strains are investigated. The computational results indicate that with the increase of aspect ratio, the critical buckling strains will decrease. For both armchair and zigzag DWCNTs, the critical buckling strains are generally larger than those of the single-wall carbon nanotubes with the same chirality as the external layers and those of the same structures without Van der Waals' force. For defective DWCNTs, the buckling strains of each order decrease by a maximum amplitude of 32.3%.

Effect of van der Waals force on wave propagation in viscoelastic double-walled carbon nanotubes

2018 ◽  
Vol 32 (24) ◽  
pp. 1850291
Author(s):  
Yugang Tang ◽  
Ying Liu
Keyword(s):  
Carbon Nanotubes ◽  
Wave Propagation ◽  
Van Der Waals ◽  
Van Der Waals Force ◽  
Strain Gradient Theory ◽  
Flexural Wave ◽  
Gradient Theory ◽  
Beam Model ◽  
Double Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

In this paper, the influence of van der Waals force on the wave propagation in viscoelastic double-walled carbon nanotubes (DWCNTs) is investigated. The governing equations of wave motion are derived based on the nonlocal strain gradient theory and double-walled Timoshenko beam model. The effects of viscosity, van der Waals force, as well as size effects on the wave propagation in DWCNTs are clarified. The results show that effects of van der Waals force on waves in inner and outer layers of DWCNTs are different. Flexural wave (FW) in outer layer and shear wave (SW) in inner layer are sensitive to van der Waals force, and display new phenomena. This new finding may provide some useful guidance in the acoustic design of nanostructures with DWCNTs as basic elements.

The Computation of Elastic Constants of Double Wall Carbon Nanotubes Based on the Finite Element Method Considering Van Der Waals' Force

2012 ◽  
Vol 562-564 ◽  
pp. 334-338 ◽  
Author(s):  
Li Jie Chen ◽  
Lin Bo Li ◽  
Qi Zhao
Keyword(s):  
Finite Element Method ◽  
Carbon Nanotubes ◽  
Finite Element ◽  
Aspect Ratio ◽  
Elastic Constants ◽  
Van Der Waals ◽  
Van Der Waals Force ◽  
Internal Layer ◽  
The Finite Element Method ◽  
Double Wall

Based on the finite element method (FEM), we study the elastic constants of double-wall carbon nanotubes (DWCNTs). In the models, the Lennard-Jones potential function is used to consider the Van der Waals' force between non-bond atoms from different layers. The variations of the elastic constants with the diameter and the aspect ratio of the internal layer nanotube are investigated systematically. The computational results indicate that for both the armchair and the zigzag DWCNTs, the elastic moduli are generally lower than those of the single-wall carbon nanotubes with the same chirality as the internal and external layers. With the increase of the diameter and the aspect ratio of the internal layer carbon nanotubes, the elastic constant of DWCNTs will fall to a stable value.

Finite Element Modeling of van der Waals Interaction for Elastic Stability of Multi-Walled Carbon Nanotubes

2008 ◽  
Vol 55-57 ◽  
pp. 525-528 ◽  
Author(s):  
Chawis Thongyothee ◽  
Somchai Chucheepsakul
Keyword(s):  
Carbon Nanotubes ◽  
Finite Element ◽  
Van Der Waals ◽  
Compressive Force ◽  
Covalent Bond ◽  
Van Der Waals Force ◽  
Tube Length ◽  
Axial Compressive Force ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The purpose of this study is to assess the effect of van der Waals interactions within multi-walled carbon nanotubes with the three dimensional finite element models. The elastic buckling behaviors of nanotubes are treated under axial compressive force acting on open both ends of nanotubes and considered with various boundary conditions. The analysis is based on the assumptions that the covalent bond of each wall is represented by an elastic beam element while the van der Waals force of adjacent walls are represented by a nonlinear truss element following the Lennard-Jones “6-12” theory. The models of double-walled carbon nanotubes are used to explain the characteristic of multi-walled carbon nanotubes and then results compared with the column theory. The results show that the critical load of nanotubes depends on atomic arrangement, tube length, and number of walls, while the van der Waals force has a small effect on the buckling load for multi-walled carbon nanotubes.

Atomistically derived metal–ceramic interfaces cohesive law based on the van der Waals force

2013 ◽  
Vol 111 ◽  
pp. 98-105 ◽  
Author(s):  
Kunjun Deng ◽  
Zhaoxia Yu ◽  
Jianqiu Zhou ◽  
Hongxi Liu ◽  
Shu Zhang
Keyword(s):  
Van Der Waals ◽  
Van Der Waals Force ◽  
Cohesive Law ◽  
Metal Ceramic ◽  
Ceramic Interfaces

Spin–curvature interaction from curved Dirac equation: Application to single-wall carbon nanotubes

2017 ◽  
Vol 31 (15) ◽  
pp. 1750120
Author(s):  
Kai Zhang ◽  
Erhu Zhang ◽  
Huawei Chen ◽  
Shengli Zhang
Keyword(s):  
Carbon Nanotubes ◽  
Dirac Equation ◽  
Single Wall Carbon Nanotubes ◽  
Cylinder Surface ◽  
Effective Hamiltonian ◽  
Spinor Structure ◽  
Single Wall Carbon ◽  
Armchair Nanotubes ◽  
Energy Approximation ◽  
Analytical Expressions

The spin–curvature interaction (SCI) and its effects are investigated based on curved Dirac equation. Through the low-energy approximation of curved Dirac equation, the Hamiltonian of SCI is obtained and depends on the geometry and spinor structure of manifold. We find that the curvature can be considered as field strength and couples with spin through Zeeman-like term. Then, we use dimension reduction to derive the local Hamiltonian of SCI for cylinder surface, which implies that the effective Hamiltonian of single-wall carbon nanotubes results from the geometry and spinor structure of lattice and includes two types of interactions: one does not break any symmetries of the lattice and only shifts the Dirac points for all nanotubes, while the other one does and opens the gaps except for armchair nanotubes. At last, analytical expressions of the band gaps and the shifts of their positions induced by curvature are given for metallic nanotubes. These results agree well with experiments and can be verified experimentally.

Sign in / Sign up

Export Citation Format

Share Document