The Effects of Surface and Initial Stresses on the Bending Stiffness of Nanowires

A simple closed-form analytic solution has been obtained for the effect of initial residual stress on the bending stiffness and hence the natural frequency of a coaxial core–shell nanowire. The result obtained also applies for a pre-stressed macro core–shell structure or a simple nanowire. The relative effect of the initial residual stress is generally limited to the range of the material yield strain. The effect of the surface elasticity on the bending stiffness of a nanowire reduces with the increase in the diameter, but the initial surface stress effect can be retained for a nanowire or microwire at a constant level of up to the limit of elastic strain if it can be controlled, for example by the application of an electrical potential