Effects of Interface Conditions on Thermo-Mechanical Fields of Multi-Phase Nano-Fibers/Particles

Abstract

The stress field of a multi-phase spherical / cylindrical inhomogeneity with arbitrary interface bonding conditions, subjected to both a uniform temperature change and a uniform hydrostatic tension, is presented. Imperfect bonding conditions are modeled using linear spring model and coherent interface model. In nanosize inhomogeneities, since the surface energy is not negligible with respect to the bulk energy, the effect of surface stresses is incorporated into the formulation. Accurate estimates for the thermal stresses of a functionally graded coated inhomogeneity with perfect and /~or imperfect interfaces are given. The influence of coating stiffness, coating thickness and interface conditions on the distribution of stress field is examined. It is observed that even a very thin coating has a prominent effect on stress distribution; hence, its exclusion from the model will lead to erroneous results.