From digital image of microstructure to the size of representative volume element: B4C/Al composite

In the field of micromechanics, the notion of representative volume element (RVE) and its quantitative definition are of the paramount importance. The definitions of RVE, used by scientists for different purposes, are mathematically strict but do not quantify its size. Furthermore, all the methods of RVE size determination (available in a voluminous literature) require a large number of numerical calculations like, for instance, those of finite element or other numerical techniques. In this paper, it is shown that the size of RVE can be evaluated based only on the morphology of microstructure that is involved in the statistical microstructure descriptor, namely the two-point correlation function. A methodology is applied to the digital image of the reconstructed 2D realization of the boron-carbide/aluminum (B4C/Al) composite. The condition for the minimum size of RVE used in the numerical procedure has been formulated in previous work of authors. The size of RVE is determined for different values of estimation error and the contrast in phase properties. The method is verified by performing numerical calculations of effective thermal conductivity coefficient.