The Tersoff-Brenner many-body potential function was used to perform molecular dynamics simulations of the tensile and fatigue behaviors of hypothetical Si-based tubular nanostructures at various temperatures, strain rates and vacancy percentages. The tensile test results indicated that, with a predicted Young’s modulus of about 60GPa, the Si nanotubes were significantly less stiff than conventional C nanotubes. It was observed that the presence of H had a significant influence on the tensile strength of Si nanotubes. The present results also indicated that the tensile strength clearly decreased with increasing temperature and with decreasing strain rate. It was shown that the majority of the mechanical properties considered decreased with increasing vacancy percentage. A standard theoretical model was used to derive curves of stress amplitude versus number of cycles. The results demonstrated that the fatigue limit of Si nanotubes increased with a decreasing vacancy percentage and with increasing temperature.

Effects of Temperature, Strain Rate and Vacancies on Tensile and Fatigue Behaviors of Silicon-Based Nanotubes. Y.R.Jeng, P.C.Tsai, T.H.Fang: Physical Review B, 2005, 71[8], 085411 (8pp)