Torsional buckling analysis of chiral multi-walled carbon nanotubes based on an accurate molecular mechanics model

This study is concerned with the torsional buckling behavior of chiral multi-walled carbon nanotubes (MWCNTs) based on a molecular mechanics model. An analytical solution is carried out to calculate the elastic critical buckling shear strain of MWCNTs with different types of chirality. To determine the force constants used in the molecular mechanics model, on the basis of quantum mechanics, density functional theory is employed. Through comparison of the results obtained from the present molecular mechanics model and ones from available molecular dynamics simulations, the validity of the present approach is assessed. The influence of chirality on the critical buckling shear strain of nanotubes is then investigated. It is indicated that nanotubes with (n, n/2) chirality buckle at lower values of critical buckling shear strain compared with zigzag and armchair nanotubes.