RAPID GENERATION OF PARTICLE PACKS AT HIGH PACKING RATIOS FOR DEM SIMULATIONS OF GRANULAR COMPACTS

Abstract

IN THIS WORK WE PRESENT A SIMPLE, FAST TECHNIQUE FOR GENERATING PARTICLE PACKS AT HIGH PACKING RATIOS AIMING AT THE SIMULATION OF GRANULAR COMPACTS VIA THE DISCRETE ELEMENT METHOD (DEM). WE START FROM A RANDOM SEQUENCE ADDITION PARTICLE GENERATION ALGORITHM TO GENERATE A ÂLAYERÂ OF NON-OVERLAPPING SPHERICAL PARTICLES THAT ARE LET TO EVOLVE DYNAMICALLY IN TIME UNDER THE ACTION OF ÂCOMPACTINGÂ OR ÂJAMMINGÂ PSEUDO FORCES. A ÂLAYER-BY-LAYERÂ APPROACH IS THEN FOLLOWED TO GENERATE MULTIPLE LAYERS ON TOP OF EACH OTHER. IN THE END, VERY DENSE PACKS WITH PRE-DEFINED BULK SHAPES AND SIZES (E.G. RECTANGLES IN TWO DIMENSIONS AND PRISMS IN THREE DIMENSIONS) ARE ACHIEVED. THE INFLUENCE OF ROLLING MOTION (WITH PARTICLE ROTATION AND SPIN) ALONG WITH INTER-PARTICLE FRICTION ON THE DENSITY AND ORDERING OF THE GENERATED PACKS IS ASSESSED. BOTH CONGRUENT AND INHOMOGENEOUS PACKS (WITH RESPECT TO PARTICLE SIZES) ARE CREATED AND THEIR PACKING PROPERTIES EVALUATED. WE BELIEVE THAT SIMPLE TECHNIQUES FOR FAST GENERATION OF PARTICLE PACKS AT HIGH PACKING RATIOS ARE ESSENTIAL TOOLS FOR THE DEM SIMULATION OF GRANULAR COMPACTS.