GEOC - modelling of microstructure of geocomposites
The micro FE analysis, in which FEM is adapted for the derivation of material behaviour from its complex microstructure. This modelling helps in the assessment and optimization of the grouting technology. Its goal may be to find out some physical parameters of materials, which have complicated heterogeneous inner structure, but which can be considered as piecewise homogeneous from a certain scale.
Description
We are interested in geocomposite materials produced by injection of polyurethane resin into coal environment, e.g. to reinforce coal pillars. Due to permeable and fractured coal, the geocomposites have complex microstructure making their FE analysis difficult.
Our model captures the microstructure of a cubic geocomposite sample 75mm in size, which has been scanned with a special industrial X-ray computer tomograph producing a set of images corresponding to cuts through the sample.
Discretization
A domain is discretized by a uniform grid of 231 × 231 × 37 grid voxels, resulting in a linear system of 6 135 936 DOF. The model assumes homogeneous material in voxels, which is assigned according to the CT scan values. We compute the homogenized material properties of the cube making use of numerical upscaling via stress and strain driven tests.