Apparent thermal contraction of single-walled carbon nanotubes

The thermomechanical behavior of single-walled carbon nanotubes (SWCNTs) is governed by the competition between quasistatic thermal expansion and dynamic thermal vibration, while the vibration effect is more prominent and induces apparent contraction in both radial and axial directions. We perform extensive molecular-dynamics simulations to explore the mechanisms of thermal expansion and apparent contraction of SWCNTs. The contributions of various vibration modes to apparent thermal contraction are analyzed explicitly at different temperatures. Parallel continuum analyses are also used to validate the vibration characteristics.