Higher-order surface stress effects on buckling of nanowires under uniaxial compression

Surface effects often play a significant role in the physical properties of micro- and nanosized materials and structures. In the literature the mathematical framework of surface/interface stresses are generally described by generalized Young-Laplace equations based on the membrane theory. Here we present a simple model based on the Kirchhoff-Love assumption and balances of force and moments to simulate higher-order interface stresses along the interface between two neighboring media in two dimensions. This framework allows us to incorporate the in-plane stress as well as the bending stiffness resulting from the non-uniform surface stress across the layer thickness. To illustrate surface stress effects, we consider the critical force of axial buckling of a nanowire by accounting various degrees of surface stresses. This study might be helpful to characterize the mechanical properties of nanowires in a wide range of applications.