近日，课题组在JCR数学一区期刊“Mathematics and Mechanics of Solids”第22卷第3期（2017）上发表题为“Surface mechanics implications for a nanovoided metallic thin-plate under uniform boundary loading”的研究论文，论文官方网页和简要内容如下。

论文官方网页：

http://journals.sagepub.com/doi/10.1177/1081286515595262

Abstract:

The goal of this work is to shed some light on the problem of stress concentrations near nanoscale pores (nanovoids) in metallic thin-plates subjected to mechanical load. The limitations of classical elasticity at the nanoscale can be mitigated by the incorporation of a coherent surface model. The disturbance of the elastic field due to a nanovoid in an elastic thin-plate can be determined using a three-dimensional displacement formulation. Numerical results suggest that the surface energy and corresponding surface stress of the nanovoid significantly alter the local stress distribution and the relevant stress concentrations. The magnitude of this effect depends on parameters like the void size, film thickness, applied load, and material properties of the thin-plate and the void surface. The results of the study suggest that nanoporous thin-plates could be optimized for lower stress concentrations and might be less vulnerable to fracture, at least when subjected to uniaxial tensile loads.

Keywords:

Surface effect, thin-plate, nanovoid, stress concentration, uniaxial load

Conclusions:

In this manuscript, we analyzed in detail the stress distributions around a nanoscale spherical cavity, embedded in a thin-plate with comparable characteristic thickness. The analytical solution was obtained by coupling a popular coherent surface model [5] with the classical, three-dimensional methodology of displacement potentials. As a result of the discontinuous tractions across the void surface, the incorporation of the coherent surface model yields appreciable additional stresses in the thin-plate. The significance of the void surface effect is dependent on several factors, including the material properties of both the thin-plate and the void surface, the characteristic lengths of the system, and the magnitude and sign of the applied load. We found that for nominal values of surface properties and applied loads, the incorporation of surface effects tends to reduce the stress concentrations in the vicinity of a nanovoid. This reduction can be substantial, as in certain locations, particularly near the thin-plate surfaces, stresses become compressive.

As a result of this study, one might suggest that nanoporous thin-plates are less susceptible to high stress concentrations and therefore less likely to fracture when subjected to uniaxial tension. In addition, the analysis suggests that, to the degree we are able to influence the material surface constants, we could be in a position to modify or even control stress concentrations in material systems that involve porous thin-plates or thin films.