Brownian forces in sheared granular matter

TL;DR

This paper demonstrates that the statistical properties of a sheared granular medium can be modeled using Brownian motion assumptions, providing a new quantitative framework for understanding driven instabilities in granular systems.

Contribution

It introduces a novel application of Brownian motion to describe force fluctuations in sheared granular matter, extending the approach to a broader class of driven instabilities.

Findings

Force fluctuations follow Brownian motion statistics

Quantitative agreement with experimental data

Applicable to other driven instability phenomena

Abstract

We present results from a series of experiments on a granular medium sheared in a Couette geometry and show that their statistical properties can be computed in a quantitative way from the assumption that the resultant from the set of forces acting in the system performs a Brownian motion. The same assumption has been utilised, with success, to describe other phenomena, such as the Barkhausen effect in ferromagnets, and so the scheme suggests itself as a more general description of a wider class of driven instabilities.