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From:
"Structural Instability of Carbon Nanotube, by I-Ling Chang, National Cheng Kung University, Taiwan, Chapter 14 in: Carbon Nanotubes - Synthesis, Characterization, Applications", edited by Dr. Siva Yellampalli, July 2011, ISBN 978-953-307-497-9, InTech, Available from: http://www.intechopen.com/books/carbon-nanotubes-synthesis-characterization-applications/structural- instability-of-carbon-nanotube
In this work, molecular dynamics approach is employed to study the buckling behaviors of single-walled carbon nanotubes with different geometric sizes and chiralities under room temperature. Based on the MD simulation results, it is observed that the nanotube’s buckling behavior transits from shell wall type for a short tube to column type for a long tube of the same radius irrespective to the chirality of the CNTs. Moreover, the buckling strain is getting smaller as the CNT becomes slender for most nanotubes, which implies that the slender nanotubes have lower buckling resistance. Under similar length-to-radius ratio, it is noted that the buckling strain decreases as the radius of the CNT increases especially for CNTs with smaller slenderness ratios. From the comparison with the prediction made by continuum buckling theories, it is concluded that the corresponding buckling strain and buckling type predicted by the continuum theory could agree reasonably well with MD simulations of the CNTs under compression except at the transition region. From the findings of this paper, it is suggested that the continuum buckling theory with proper choice of parameters, i.e., wall thickness and Poisson’s ratio, could capture the trend of the buckling strain on the length-to-radius ratio disregarding to the helical types (i.e., armchair, zigzag and chiral) of the nanotubes and, hence, could serve as a primitive guideline in predicting the buckling strain of the CNTs.
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