Visualization of the Force Network Microstructure in 3D Experiments

Abstract The paper presents selected images of the force network recorded during the uniaxial compression test of cuboidal samples formed from polidymethylosiloxane (PDMS) grains of different diameters. The experiments were carried out using the photo-elastic method. The self-manufactured spherical grains of PDMS elastomer were used as substitutes for natural granular materials. The images of the tests were registered from four sides of the samples by rotating the test box to enable inspection in the usual out-of-plane direction. It is shown that the minimum aspect ratio is responsible for the transition between pseudo-2D and 3D force network structure. The high sensitivity of that structure to geometrical test conditions was found.