Preparation and observation of jammed particles with power size distribution

TL;DR

This study investigates the structure of jammed particles with a power size distribution through experiments and simulations, revealing fractal structures and dependencies on size distribution parameters.

Contribution

It introduces a coarse-grained model for powders with large size variations and analyzes their jamming transition structure both experimentally and numerically.

Findings

Fractal structures with cutoffs were observed experimentally and numerically.

The area fraction of rattlers is nearly independent of the size distribution exponent.

The number fraction of rattlers varies significantly with the size distribution exponent.

Abstract

Several materials, such as rocks, powders and molecules, are multi-component systems. However, compared to single-component systems, it is difficult to understand the physical component. In this study, as a coarse-grained model for powders with extremely large size variations, we experimentally and numerically filled circular particles with a power size distribution and investigated their structure at the jamming transition point. In the experiment, oil in water droplets following a power size distribution were created, and then we constructed a model with steady injection and fracture to explain the size distribution. In numerical calculations, the dependence of the packing structure on the exponent of the particle size distribution was investigated. The existence of fractal structure with cutoffs was experimentally and numerically found from the structure factor. Numerical calculations show that the area fraction of rattlers is almost independent of exponent, but the number fraction is significantly dependent.