Structural signature and contact force distributions in the simulated three-dimensional sphere packs subjected to uniaxial compression

Packing of spherical particles in a three-dimensional cylindrical container is simulated by using Discrete Element Method. The packed bed of spheres is also subjected to vertical compression which results in a dense compact. Microstructures of the packing during compaction are examined in detail in terms of the contact number, deviator fabric, and radial distribution function. Furthermore, contact force distributions are measured at different locations in the pack, i.e. the centre, the side wall, and the base (or bottom wall) of the container. The simulations show that random close packing (RCP) tends to exist in the centre of the pack, while ordered packing structures exist near the container's walls. The uniaxial compression doesn't seem to alter the packing structure in the pack centre remarkably, but to reduce the structural anisotropy of the packing close to the container's base. The simulated results have also helped to establish the correlations between packing structures and contact force distributions. Further, it is shown that small contact force distributions are sensitive to local packing structures. The simulated results are shown to be consistent with the recent experimental and simulation findings.