MECHANICAL MODELING OF GRAIN-BOUNDARY SLIDING OF POLYCRYSTALS

Using a variational method, a general three-dimensional solution to th e problem of a sliding spherical inclusion embedded in an infinite ani sotropic medium is presented in this paper. The inclusion itself is al so a general anisotropic elastic medium. The interface is treated as a thin interface layer with interphase anisotropic properties. The disp lacements in the matrix and the inclusion are expressed as polynomial series of the cartesian coordinate components. Using the virtual work principle, a set of linear algebraic equations about unknown coefficie nts are obtained. Then the general sliding spherical inclusion problem is accurately solved. Based on this solution, a self-consistent metho d for sliding polycrystals is proposed. Combining this with a two-dime nsional model of an aggregate polycrystal, a systematic analysis of th e mechanical behaviour of sliding polycrystals is given in detail. Num erical results are given to show the significant effect of grain bound ary sliding on the overall mechanical properties of aggregate polycrys tals.