Mechanical behavior of nanowires with high-order surface stress effects

Surface in solids could behave differently from their bulk part, especially when the size of the solid is on the nanoscale. It has been widely accepted that the continuum mechanics framework along with a suitable implementation of the surface effect, referred to as surface stress model, could serve as a useful tool in the analysis of mechanical behavior of nanosized solids and structures. Here we review the surface stress model briefly and outline recent progress in application to mechanics of nanosolids or nanocomposites. A refined model, termed high-order surface stress model proposed by the authors few years ago, was recapitulated here, particularly for two-dimensional configurations. The distinction between the two frameworks is highlighted from the viewpoint of a simple geometric exposition of mechanics of thin plate and shell. We demonstrate that, by comparison with experimental data, the incorporation of high-order surface stress could be critical in certain situations to capture the trend observed by the experimental observation. Some illustrations are directed to the mechanics of nanowires, including bending and bulking behavior. Future potential subjects along the trend are suggested.