A refined molecular life prediction scheme for single-walled carbon nanotubes, taking into consideration C-C bond rotation and pre-existing strain under mechanical loads, was proposed. The time-dependent fracture behavior of 12 different cases of zig-zag (18,0) single-walled carbon nanotubes, each embedded with either a single Stone-Wales defect of different types or two interacting or non-interacting defects, was studied under axially applied tensile load. It was shown that the patterns of atomistic crack propagation and fatigue lives of single-walled carbon nanotubes were influenced by the type and orientation of the Stone-Wales defect(s), inter-defect distance, as well as the magnitude of externally applied stress. For single-walled carbon nanotubes with two Stone-Wales defects, if the inter-defect distance was within the so called indifference length, defect-defect interaction did exist, and it had pronounced effects on diminishing the lives of the nanotubes. Also, the defect-defect interaction was stronger at shorter inter-defect distance, resulting in shorter fatigue lives.

Effect of Inter-Defect Interaction on Tensile Fatigue Behavior of a Single-Walled Carbon Nanotube with Stone-Wales Defects. Z.R.Zhou, K.Liao: Journal of Applied Mechanics, Transactions ASME, 2013, 80[5], 051005