Enhanced torsional stability of carbon nanotubes with tensile pre-strain

• Tensile pre-strains greatly enhance the torsional stability of carbon nanotubes.
• Increase rates of buckling torques are in proportion to the degrees of tensile pre-strains.
• Increase rates of buckling torques are much larger in zigzag carbon nanotubes.
• Maximum increase rate of buckling torque is 122.3% in zigzag carbon nanotubes.
• Tensile pre-strains also alter the torsional stiffness of carbon nanotubes.

This work examines the torsional mechanical properties of single-walled carbon nanotubes with tensile pre-strains using classical molecular dynamics simulations. In particular, it is investigated how much the tensile pre-strains enhance the torsional stability of nanotubes, and how this enhanced torsional stability is dependent on the chirality of nanotubes. The observations reveal that the tensile pre-strains greatly enhance the torsional stability of nanotubes and the effects are strongly dependent on the degrees of tensile pre-strains and the chirality of nanotubes. The increase rates of torsional buckling moments are in proportion to the degrees of tensile pre-strains and much larger in zigzag nanotubes than in armchair nanotubes. In the case of zigzag nanotubes, the maximum increase rate of torsional buckling moment is 122.3% for the tensile pre-strain of 0.115. In addition, the tensile pre-strains also alter the torsional stiffness of nanotubes depending on the degrees of tensile pre-strains and the chirality of nanotubes.