Tensile strength of carbon nanotubes under realistic temperature and strain rate

A transition state theory based predictive model is developed for the tensile failure of carbon nanotubes (CNT's). We show that the tensile yield strain has linear dependence on the activation energy and the temperature, and has a logarithmic dependence on the strain rate. Based on the parameters fitted from strain rate and temperature-dependent simulations within a wide range of molecular-dynamics time scales, the model predicts that a defect-free micrometer long single-wall nanotube at 300 K, stretched with a strain rate of 1%/h, yields at about 9+/-1% tensile strain for small diameter CNT's, and about 2-3 % higher for larger diameter CNT's. This is in good agreement with recent experimental findings.