Molecular dynamics simulation of free transverse vibration behavior of single-walled coiled carbon nanotubes

Coiled carbon nanotubes (CCNTs) belong to one of the prominent classes of carbon nanostructures with unique mechanical properties and vibrational behavior due to their helical geometries. In this paper, the free transverse vibration behavior of single-walled CCNTs is investigated by molecular dynamics (MD) simulations and the adaptive intermolecular reactive empirical bond-order (AIREBO) potential under different boundary conditions (B.Cs.). The beating phenomenon is observed in CCNTs due to the presence of longitudinal, transverse, and torsional coupled vibrations and the proximity of their corresponding frequency. Generally, the frequency of the CCNTs decreases by increasing the length (L) or the number of pitches (n(p)). Moreover, the pitch angle (a over bar ) plays a more decisive role compared to other geometric parameters. At constant length (L) of CCNTs, the frequency increases by enhancing the pitch angle (a over bar ). Furthermore, the fundamental frequency range of the studied CCNTs is obtained less than 331.9 GHz for lengths greater than 2 nm under different boundary conditions. This indicates that CCNTs have a higher vibration sensitivity than straight CNTs. Therefore, CCNTs can be a proper alternative to straight CNTs in sensors. The results of this study can be used in the design and analysis of nanoelectromechanical systems (NEMs) with CCNTs elements as well as to calibrate continuum mechanics methods.

Automated summary

The free transverse vibration behavior of coiled carbon nanotubes (CCNTs), which exhibit beating phenomenon due to longitudinal, transverse, and torsional coupled vibrations, is investigated in this paper using molecular dynamics simulations. The study finds that the frequency of CCNTs decreases with increasing length or number of pitches. The pitch angle has a more decisive role compared to other geometric parameters, and increasing it increases the frequency. The fundamental frequency range of CCNTs is obtained to be less than 331.9 GHz for lengths greater than 2 nm under different boundary conditions, indicating higher vibration sensitivity than straight carbon nanotubes.