Examining the effects of wall numbers on buckling behavior and mechanical properties of multiwalled carbon nanotubes via molecular dynamics simulations

Abstract

Molecular dynamics simulations are performed on multiwalled carbon nanotubes ͑MWCNTs͒ under axial compression to investigate the effects of the number of walls and their van der Waals ͑vdW͒ interaction on the buckling behaviors and mechanical properties ͑Young's modulus and Poisson's ratio͒. The Brenner second-generation reactive empirical bond order and Lennard-Jones 12-6 potential have been adopted to describe the short-range bonding and long-range vdW atomic interaction within the carbon nanotubes, respectively. In the presence of vdW interaction, the buckling strain and Young's modulus of MWCNTs increase as the number of tubes is increased while keeping the outermost tube diameter constant, whereas Poisson's ratio was observed to decrease. On the other hand, when the MWCNTs are formed by progressively adding outer tubes while keeping the innermost tube diameter constant, Young's modulus and buckling strain were observed to decrease, whereas Poisson's ratio increases. The buckling load increases with increasing the number of walls due to the larger cross-sectional areas. Individual tubes of MWCNTs with a relatively large difference between the diameters of the inner and outer tubes buckle one at a time as opposed to simultaneously for MWCNTs with a relatively small difference in diameters.

Molecular Dynamics Simulation and Continuum Shell Model for Buckling Analysis of Carbon Nanotubes

“…When the torsional potential term is switched off in the AIREBO potential, the critical buckling strain of CNTs becomes closer to that obtained using REBO 2nd þ LJ potential. For instance, the critical buckling strain of a 60 Å DWCNT((5,5),(10,10)) obtained using AIREBO potential without the torsional potential term is 0.0543 which agrees well with 0.0553 obtained by Zhang et al (2008) who used the REBO 2nd þ LJ potential. Thus, it is clear that the inclusion of the torsion term in the interatomic potential leads to a significant reduction in the critical buckling strain.…”

Buckling of Carbon Nanotubes: A State of the Art Review

“…Owing to their nanometric scales, similarities and differences in buckled patterns compared with macroscopic counterparts should not be trivial at all. This complexity has motivated tremendous efforts toward the buckling analysis of carbon nanotubes under diverse loading conditions: axial compression [18,19,20,21,22,23,24,25,26,27,28], radial compression [29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63], bending [41,64,65,66,67,68,69,70,71], torsion [72,73,74,75,76,77], and their certain combinations [78,79<...>…”

“…Owing to their nanometric scales, similarities and differences in buckled patterns compared with macroscopic counterparts should not be trivial at all. This complexity has motivated tremendous efforts toward the buckling analysis of carbon nanotubes under diverse loading conditions: axial compression [15][16][17][18][19][20][21][22][23][24][25], radial compression , bending [38,[61][62][63][64][65][66][67][68], torsion [69][70][71][72][73][74], and their certain combinations [75][76][77][78][79]. Such extensive studies have been driven primarily by the following two facts.…”

Axial buckling of multiwall carbon nanotubes with heterogeneous boundaries

“…Nevertheless, this issue has not been examined for MWCNTs of more than two layers. Moreover, in all previous buckling analyses, [4][5][6][7][8][9][10][11][12][13][14][15] MWCNTs are always assumed to have homogeneous boundary condition, i.e., the same boundary condition is specified on all the constituent tubes of MWCNTs. This assumption, used to simplify the analysis, may not be always true in many engineering applications of CNTs.…”