Experiments and Simulations on Vibration Induced Densification of Bulk Solids

Abstract

The change in bulk density or solids fraction that occurs when a vessel of granular materials is vibrated is an important, industrially-relevant process. In this paper, we present findings from experiments and discrete element simulations on the relaxation behavior of assemblies of uniform spheres that are vertically oscillated. Physical measurements of the bulk solids fraction, qualitatively reproduced in the simulations, reveal noticeable trends in the data dependent on the vibration amplitude and frequency. By carrying out extended simulations, a ‘phase’ chart depicting the percentage improvement in bulk density in terms of amplitude and frequency is obtained. Our results suggest that the behavior revealed in this chart may be characteristic of density relaxation in bulk solids.