Finite element microstructural homogenization techniques and intergranular, intragranular microstructural effects on effective diffusion coefficient of heterogeneous polycrystalline composite media

摘要

Microstructural intergranular and intragranular effects play a vitally important role in mass transport within heterogeneous polycrystalline composite media. Full scale macroscopic specimen or component modelling of heterogeneous polycrystalline composite media is complex, time consuming and computationally expensive. Consequently it is important to develop a homogenous model to predict the effective diffusion coefficient of the heterogeneous polycrystalline composite media. It is also important to investigate the effect of intergranular and intragranular microstructure on effective diffusivity of heterogeneous polycrystalline composite media. A two dimensional finite element microstructural representative volume element (FEMRVE) model with different intergranular and intragranular micro-structures has been developed using the well-known Voronoi tessellation technique. The effective diffusivity predicted by the FEMRVE model with various intergranular and intragranular microstructures of heterogeneous polycrystalline composite media agrees well with the results of various effective medium theories.