Hard particle jamming in the limit of zero pressure is well studied in granular physics, but many applications are far from this limit. As pressure increases, rearrangement is no longer the only mechanism for densification as grains will deform and eventually fracture. The breakdown of granular matter, or comminution, produces irregular shapes and sizes and affects macroscopic properties including rheology. We explore the compaction of brittle granular systems using bonded discrete element simulations. Each grain is composed of many smaller, fundamental particles which are connected by a network of breakable bonds. This allows grains to crack and fragment. During loading, we monitor both the evolution of macroscopic properties (e.g. stress and porosity) as well as the evolution of grain size distributions. We explore how compaction depends on strain rate and material properties. Finally, the pressure at which single grains fail is identified and compared to theory.
Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA-0003525.