Buckling and Post-Buckling of Cantilevered Single-Walled Carbon Nanotubes in Bending

2015 ◽  
Vol 14 (05n06) ◽  
pp. 1550019
Author(s):  
Matukumilli V. D. Prasad ◽  
Baidurya Bhattacharya
Keyword(s):  
Carbon Nanotubes ◽  
Atomistic Simulations ◽  
Linear Elastic ◽  
Buckling Behavior ◽  
Potential Applications ◽  
Post Buckling ◽  
Critical Location ◽  
Walled Carbon Nanotubes ◽  
Hinge Angle ◽  
Single Walled Cnts

There are various potential applications in which carbon nanotubes (CNTs) may be subjected to bending in a cantilevered configuration leading to buckling which in turn may affect their electrical, electronic as well as load bearing properties. Using atomistic simulations, we study buckling and post-buckling behavior of six single-walled CNTs subjected to bending in cantilever loading (i.e., flexure in addition to shear and axial compression). Starting with small kinks on the compression side corresponding to locations of high strain energy density, ripples form on the tube wall as bending progresses, until the tube flattens maximally at a critical location giving rise to a stable hinge that rotates under continued bending. The critical buckling curvature, locations of initial and stable hinges and rotational properties of the hinge are determined. Beyond the linear elastic region, the rotational stiffness depends on the hinge angle dropping close to zero (at the same angle for each tube) before beginning to rise again, reminiscent of snap-through buckling of shells, a property that can be exploited for sensing and signal amplification applications.

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.

Mechanical and Tribological Properties of Carbon Nanotubes Investigated with Atomistic Simulations

2000 ◽  
Vol 633 ◽  
Author(s):  
Boris Ni ◽  
Susan B. Sinnott
Keyword(s):  
Carbon Nanotubes ◽  
Atomistic Simulations ◽  
Many Body ◽  
Jones Potential ◽  
Diamond Surfaces ◽  
Empirical Potential ◽  
Mechanical And Tribological Properties ◽  
Lennard Jones ◽  
Walled Carbon Nanotubes ◽  
Nanotube Bundle

AbstractAtomistic simulations are used to better understand the behavior of bundles of single- walled carbon nanotubes that have been placed between two sliding diamond surfaces. A many-body reactive empirical potential for hydrocarbons that has been coupled to a Lennard-Jones potential is used to determine the energies and forces for all the atoms in the simulations. The results indicate that the degree of compression of the nanotube bundle between the nanotubes has a significant effect on the responses of the nanotubes to shear forces. However, no rolling of the nanotubes is predicted in contrast to previous studies of individual nanotubes moving on graphite.

Molecular Dynamics Simulation of Bi-Carboxyl Sidewall Functionalized Single-Wall Carbon Nanotubes in Water

2015 ◽  
Vol 1131 ◽  
pp. 106-109
Author(s):  
Shongpun Lokavee ◽  
Chatchawal Wongchoosuk ◽  
Teerakiat Kerdcharoen
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Single Wall Carbon Nanotubes ◽  
First Principles Calculations ◽  
Carboxylic Groups ◽  
Potential Applications ◽  
Walled Carbon Nanotubes ◽  
Defective Sites

Functionalized single-walled carbon nanotubes (f-SWNTs) have attracted great interest due to their enhancement of SWNT properties leading to an increase in potential applications beyond those of pristine SWNT. In this work, we have investigated the behavior of open-end (9,0) bi-carboxyl sidewall functionalized SWNTs in water using molecular dynamics (MD) technique within GROMACS software package based on the OPLS force fields with modified charges obtained from the first principles calculations. The model tubes including perfect and defective nanotubes covalently functionalized by bi-carboxylic groups on different sidewall surface orientation were fully optimized by B3LYP/6-31G(d,p). The simulations were performed at the constant volume and temperature in a rectangular box with periodic boundary conditions in which each system contains one model tube and ~1680 water molecules. The results form MD simulations showed that functionalization on the central carbon atom in the (C1,C ́1)SW-defective sites strongly affects on the dynamic behavior of CNT in water. Results showed that the hydrophilic behavior of the functionalized SWNT has been improved over the pristine and defective nanotubes.

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