Deformation of single-walled carbon nanotubes under large axial strains

The deformations of single-walled carbon nanotubes (SWCNTs) under large axial strains are investigated. The Tersoff–Brenner potential is adopted to describe the interactions between carbon atoms. Results show that the changes of strain energies are dependent on chirality but independent of the tubes' radii. Under large axial tension, abrupt changes of the configurations of SWCNTs may occur when the strains exceed 0.382 for armchair patterns and 0.43 for zigzag patterns. The reason is that the changes of bond lengths and angles lead to corresponding changes of many-body coupling interactions between atoms. Then the tubes reach new equilibrium states. Such abrupt changes of configurations must trigger fracture of CNTs in a dynamic deformation.