Local buckling of carbon nanotubes under bending

The discovery of a local buckling instability of a single-walled carbon nanotube (CNT) that is subjected to point loading in its flexural direction through molecular mechanics simulations via the MATERIALS STUDIO software package is reported in the letter. The sudden decrease of the stiffness of the CNT at the onset of the local instability is found from reliable observations of the second derivation of the strain energy of the CNT under bending. A mechanics model is developed to predict the onset of the local instability, and the effectiveness of the model is verified by molecular mechanics simulations.