Cylindrical hole in an elastic solid with curvature-dependent surface tension
摘要
Surface tension proves to be one of the main factors in affecting the mechanical behavior of porous structures (especially soft porous materials) at the micro- or nanoscale. In terms of theoretical study of the elastic behavior of surface tension-endowed porous materials in the literature, surface tension has commonly been treated as a constant on the entire boundary of the pores during the whole deformation process. However, an extensive collection of experimental or simulation data in the literature has demonstrated that surface tension on the surface of a specific material typically changes with the current configuration of the surface. Based on these considerations, we reexamine in this paper the plane deformation of an elastic solid containing an initially cylindrical hole in the context of a curvature-dependent surface tension model (i.e., the change in the magnitude of surface tension is proportional to that in the curvature of the hole’s boundary during the deformation caused by an external loading). We derive explicit solutions for the external loading-induced incremental elastic field in the solid, based on which the overall transverse properties of an elastic solid containing a large number of cylindrical holes are also attained following the dilute and Mori–Tanaka homogenization methods. In addition, we obtain a lower bound for the radius of the hole, in terms of the surface tension parameters and the shear modulus of the solid, ensuring the stability of the incremental elastic field in the solid, and discuss how the curvature dependence of surface tension influences the incremental stress concentration around the hole and the effective moduli of the homogenized solid.