Sharif Digital Repository

Recent studies have shown that the surface/interface free energy plays an important role in the effective mechanical properties of solids with nanosized inhomogeneity. In the present study, an analytical model is developed for 3D axisymmetric analysis of short fiber nanocomposites including the fiber end region, subjected to an applied axial load considering surface effects. Closed form expressions are obtained for 3D stress filed in the fiber and matrix. Moreover, performing numerical examples, it is shown that the elastic stress field is size dependent in both the fiber and matrix especially for fiber radii less than 50 nm  

Exact solutions for nonlinear composites undergoing finite deformation are in general difficult to find. In this article, such a solution is obtained for a two-phase composite reinforced with elliptic fibers under anti-plane shear. The analysis is based on the theory of hyperelasticity with both phases characterized by incompressible neo-Hookean strain energies, and is carried out when the composite elliptic cylinder assemblage carries a confocal microgeometry. The problem for a class of compressible neo-Hookean materials is also studied. The analytical results for the stress and strain distributions are verified with finite element calculations where excellent agreement is found. We then...