Thermal effect on axial buckling behavior of multi-walled carbon nanotubes based on nonlocal shell model

2011 ◽  
Vol 44 (2) ◽  
pp. 373-378 ◽  
Author(s):  
R. Ansari ◽  
H. Rouhi ◽  
S. Sahmani
Keyword(s):  
Carbon Nanotubes ◽  
Shell Model ◽  
Thermal Effect ◽  
Axial Buckling ◽  
Buckling Behavior ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

BUCKLING BEHAVIOR OF SHORT MULTI-WALLED CARBON NANOTUBES UNDER AXIAL COMPRESSION LOADS

2012 ◽  
Vol 12 (06) ◽  
pp. 1250045 ◽  
Author(s):  
A. H. KORAYEM ◽  
W. H. DUAN ◽  
X. L. ZHAO ◽  
C. M. WANG
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Mechanics ◽  
Axial Compression ◽  
Single Walled Carbon Nanotubes ◽  
Buckling Mode ◽  
Chiral Angle ◽  
Single Walled Carbon ◽  
Buckling Behavior ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

We investigate the buckling behaviors of short multi-walled carbon nanotubes (MWCNTs) under axial compression by using molecular mechanics (MM) simulations. The effects of the number of walls, length and chiral angle of MWCNTs on the buckling behaviors are examined. The results show that the buckling behaviors of short MWCNTs are rather different from single walled carbon nanotubes (SWCNTs) and slender MWCNTs. Moreover, it is observed that the buckling strains of short MWCNTs vary inversely proportional to the number of nanotube walls. For slender MWCNTs, the buckling strains fluctuate as the number of walls increase. It increases for beam-like buckling mode, decreases for shell-like buckling mode and is approximately constant for the shell-beam-like buckling mode. The increase in the length of MWCNT has also led to a significant decrease of the buckling strain for short MWCNTs. However, chirality does not have a significant effect on the buckling strain of MWCNTs nor alter the buckling mode of short MWCNTs.

NONLOCAL ANALYTICAL FLUGGE SHELL MODEL FOR AXIAL BUCKLING OF DOUBLE-WALLED CARBON NANOTUBES WITH DIFFERENT END CONDITIONS

NANO ◽  
2012 ◽  
Vol 07 (03) ◽  
pp. 1250018 ◽  
Author(s):  
HESSAM ROUHI ◽  
REZA ANSARI
Keyword(s):  
Carbon Nanotubes ◽  
Boundary Conditions ◽  
Shell Model ◽  
Ritz Method ◽  
Nonlocal Parameter ◽  
Geometrical Parameters ◽  
Field Equations ◽  
Axial Buckling ◽  
Double Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

In this paper, a nonlocal Flugge shell model is utilized to investigate the axial buckling behavior of double-walled carbon nanotubes (DWCNTs) under various boundary conditions. According to the nonlocal elasticity theory, the displacement field equations coupled by the van der Waals interaction are derived. The set of governing equations of motion is then solved by the Rayleigh–Ritz method. The present analysis can treat boundary conditions in a layer-wise manner. The effects of nonlocal parameter, layer-wise boundary conditions and geometrical parameters on the mechanical behavior of DWCNTs are examined. Furthermore, molecular dynamics simulations are performed to assess the validity of the results and also to predict the appropriate values of nonlocal parameter. It is found that the type of boundary conditions affects the proper value of nonlocal parameter.

Nonlocal Shear Deformable Shell Model for Post-Buckling of Axially Compressed Double-Walled Carbon Nanotubes Embedded in an Elastic Matrix

2010 ◽  
Vol 77 (4) ◽  
Author(s):  
Hui-Shen Shen ◽  
Chen-Li Zhang
Keyword(s):  
Carbon Nanotubes ◽  
Shell Model ◽  
Elastic Medium ◽  
Scale Parameter ◽  
Small Scale ◽  
Buckling Behavior ◽  
Post Buckling ◽  
Double Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Shear Deformable

Buckling and post-buckling analysis is presented for axially compressed double-walled carbon nanotubes (CNTs) embedded in an elastic matrix in thermal environments. The double-walled carbon nanotube is modeled as a nonlocal shear deformable cylindrical shell, which contains small scale effects and van der Waals interaction forces. The surrounding elastic medium is modeled as a tensionless Pasternak foundation. The post-buckling analysis is based on a higher order shear deformation shell theory with the von Kármán–Donnell-type of kinematic nonlinearity. The thermal effects are also included and the material properties are assumed to be temperature-dependent and are obtained from molecular dynamics (MD) simulations. The nonlinear prebuckling deformations of the shell and the initial local point defect, which is simulated as a dimple on the tube wall, are both taken into account. A singular perturbation technique is employed to determine the post-buckling response of the tubes and an iterative scheme is developed to obtain numerical results without using any assumption on the shape of the contact region between the tube and the elastic medium. The small scale parameter e0a is estimated by matching the buckling loads of CNTs observed from the MD simulation results with the numerical results obtained from the nonlocal shear deformable shell model. Numerical solutions are presented to show the post-buckling behavior of CNTs surrounded by an elastic medium of conventional and tensionless Pasternak foundations. The results show that buckling and post-buckling behavior of CNTs is very sensitive to the small scale parameter e0a. The results reveal that the unilateral constraint has a significant effect on the post-buckling response of CNTs when the foundation stiffness is sufficiently large.

Sign in / Sign up

Export Citation Format

Share Document