Thermomechanical buckling of boron nitride nanotubes using molecular dynamics
A Chandra and PK Patra and B Bhattacharya, MATERIALS RESEARCH EXPRESS, 3, 025005 (2016).
We study the thermal buckling behavior of precompressed boron-nitride nanotubes (BNNTs) using molecular dynamics simulations with Tersoff interatomic potential. We compute the critical buckling strains at near- zero temperature, and subsequently precompress the nanotubes at a certain fraction of this value followed by temperature ramping. The critical buckling temperature, T-cr, is marked by a sudden decrease of the internal force. We observe that (i) at small to moderate lengths, T-cr is higher for chiral nanotubes than for either armchair or zigzag nanotubes, (ii) T-cr decreases with increasing diameter unlike in thermal disintegration where disintegration temperatures rise with increasing diameter, and (iii) armchair nanotubes have an optimal length for which T-cr is maximum. We qualitatively explain the reasons for each of the findings. Thermomechanical buckling occurs predominantly in two ways depending on the length of the nanotube-while the shorter nanotubes fail by radial instability (shell-like behavior), the longer ones invariably fail due to bending-buckling (rod-like behavior).
Return to Publications page