Based upon the continuum mechanics method, three-dimensional finite element models were used to study the effects of various defects upon the vibration of armchair and zig-zag single-walled carbon nanotubes. The variations of the vibration mode and the 1st natural frequency with diameter and aspect (length/diameter) ratio were investigated. The diameter of single-walled carbon nanotubes varied from 1.0 to 2.1nm and the aspect ratio varied from 3 to 32. Double-atom vacancy defects and Stone-Wales defects were considered. The computational results showed that the length, the diameter and the defect position of single-walled carbon nanotubes were three important factors affecting the vibration properties of single-walled carbon nanotubes. For both armchair and zig-zag single-walled carbon nanotubes, the Stone-Wales defects had less effect upon the vibration properties than did the double-atom vacancy defects. The defects studied here decreased the 1st natural frequency by a large proportion of within 10%. It was also noted that, for double-atom vacancy defects, the distance between the defect and the restrained end definitely affected the 1st natural frequencies of single-walled carbon nanotubes when the distance varied from 0.3 to 4.8nm. This was not true for Stone-Wales defects. There existed a position where the distance between the defect position and the restrained end had no effect upon the 1st natural frequencies of single-walled carbon nanotubes.

The Effects of Different Defects on Vibration Properties of Single-Walled Carbon Nanotubes. L.Chen, Q.Zhao, Z.Gong: Advanced Materials Research, 2011, 225-226, 1133-6