Micromechanical modeling of particulate-filled composites using micro-CT to create representative volume elements

Abstract

A method based on X-ray micro-CT was introduced to create realistic representative volume elements (RVE) for particulate-filled composite materials. The method is applicable to most composite systems, and can be utilized to improve artificial computer algorithms by presenting the number, the dimension, and the orientation of filler particles inside the RVEs. Three different shapes of glass fillers (spherical, flake, and fiber) and filler mass fractions (5%, 10%, and 15%) were introduced to epoxy resin to demonstrate the capability of micro-CT to create RVEs. Two kind of RVEs were created; voxel-based and geometry-based. Voxel-based RVEs were created from binary segmentation of images taken from micro-CT. Geometry-based RVEs were created after reconstruction of voxel-based RVEs to eliminate the stepped-like appearance of non-orthogonal interfaces. These RVE's were then used in the finite element analysis to find the effective mechanical properties such as Young's modulus, shear modulus, Poisson's ratio of the samples. In order to assess the numerical findings, compression tests were performed according to ASTM D695. Also, spherical fillers were distributed inside a volume artificially using an algorithm and RVEs were created. The number and the dimension of the spherical fillers were supplied from X-ray micro-CT and optical microscopy, respectively. The elastic moduli found using RVEs created from the algorithm is close to the elastic moduli found using RVEs created from X-ray micro-CT.