Compaction dynamics in ductile granular media

TL;DR

This study investigates the temporal evolution of ductile granular media during compaction, revealing persistent weight oscillations linked to grain-wall contact dynamics over extended periods.

Contribution

It provides the first detailed experimental analysis of oscillatory behavior and contact dynamics in ductile granular compaction over long timescales.

Findings

Weight oscillations develop within the first ten hours.

Oscillations persist throughout the experiment duration.

Weight fluctuations are correlated with contact dynamics.

Abstract

Ductile compaction is common in many natural systems, but the temporal evolution of such systems is rarely studied. We observe surprising oscillations in the weight measured at the bottom of a self-compacting ensemble of ductile grains. The oscillations develop during the first ten hours of the experiment, and usually persist through the length of an experiment (one week). The weight oscillations are connected to the grain--wall contacts, and are directly correlated with the observed strain evolution and the dynamics of grain--wall contacts during the compaction. Here, we present the experimental results and characteristic time constants of the system, and discuss possible reasons for the measured weight oscillations.