scholarly journals Dynamic shell buckling behavior of multi-walled carbon nanotubes embedded in an elastic medium

2013 ◽  
Vol 56 (3) ◽  
pp. 483-490 ◽  
Author(s):  
ChengQi Sun ◽  
KaiXin Liu ◽  
YouShi Hong
2014 ◽  
Vol 8 (2) ◽  
pp. 151-159 ◽  
Author(s):  
Pattabhi R. Budarapu ◽  
Sudhir Sastry Yb ◽  
Brahmanandam Javvaji ◽  
D. Roy Mahapatra

2012 ◽  
Vol 12 (06) ◽  
pp. 1250045 ◽  
Author(s):  
A. H. KORAYEM ◽  
W. H. DUAN ◽  
X. L. ZHAO ◽  
C. M. WANG

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.


2010 ◽  
Vol 77 (4) ◽  
Author(s):  
Hui-Shen Shen ◽  
Chen-Li Zhang

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.


Author(s):  
Julie F. Waters ◽  
Laura Riester ◽  
Maryam Jouzi ◽  
Pradeep R. Guduru ◽  
J. M. Xu

We report shell buckling instabilities observed experimentally in multi-walled carbon nanotubes subjected to uniaxial compression and interpret the results using insights from elasticity theory and molecular dynamics simulations. Uniform hexagonal arrays of vertically-oriented, freestanding multi-walled carbon nanotubes were grown in a self-assembled, highly-ordered nanoporous alumina matrix and then placed under uniaxial compression using a nanoindenter. Both flat and spherical nanoindenter tips were used to compress many nanotubes at once, and individual nanotube behavior could be deduced from the bulk force-vs.-displacement data by using the uniformity of the nanotube arrays and the geometry of the tips. Buckling instabilities are evident in the measured force-vs.-displacement behavior. A consideration of thin shell elasticity theory and molecular dynamics models provides guidelines for interpreting the experimental results. Excellent agreement is found between the experimentally measured critical buckling loads and those predicted by theory.


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