Atomic-scale finite element analysis of vibration mode transformation in carbon nanorings and single-walled carbon nanotubes

Atomic-scale finite element analyses show that 2:1 internal resonance mechanism exists in a range of single-walled carbon nanorings (10-60). When an initial radial breathing mode (RBM) vibration with sufficiently high velocity is imposed to a nanoring, circumferential flexural modes (CFMs) can be excited after a period of RBM-dominated vibration. Then, mode transformations between RBM and the excited CFMs can be observed in the subsequent vibration process. When single-walled carbon nanorings are assembled to make double- or triple-walled carbon nanorings, the 2:1 internal resonance may change to 1:1 internal resonance in a specific ring due to the strong interactions between these nanorings. Furthermore, mode transformations between RBM and the excited CFMs can become unstable in a specific ring if the excited CFMs in neighbouring layer rings are not symmetrically matching between each other. 2:1 internal resonance is also shown in selected armchair single-walled carbon nanotubes except in a special case (armchair (9, 9)), in which 1:1 internal resonance occurs.