Molecular dynamics study on resonance frequency change due to axial-strain-induced torsions of single-walled carbon nanotubes

We investigated, via the classical MD simulation method based on Tersoff-Brenner potential, the fundamental resonance frequency changes of single-walled carbon nanotube (SWCNT) resonators originated from the purely mechanical coupling of the axial-strain-induced torsion (ASIT) response. The fundamental frequency changes were also negligible where the ASIT responses were negligible in achiral SWCNTs whereas those were explicitly found under both compression and tension for the chiral SWCNTs with the obvious ASIT responses. Specially, for SWCNT with the chiral angle of π/12, where the highest ASIT response can be found, the fundamental resonance frequency changes were highest. The fundamental resonance frequencies under the tensioning increased almost linearly with increasing the axial strain whereas they rapidly decreased under compression with increasing the compressive strain.