Force Distributions in Frictional Granular Media

TL;DR

This paper combines experiments and theory to analyze the force distributions in frictional granular media, revealing new joint probability functions and predicting slip events at low pressures.

Contribution

It introduces a novel joint probability distribution function for normal and tangential forces in amorphous frictional media using maximum entropy formalism.

Findings

Excellent agreement with experimental and simulation data.

The joint pdf predicts giant slip events at low pressures.

New theoretical framework for force distributions in granular media.

Abstract

We report a joint experimental and theoretical investigation of the probability distribution functions (pdf's) of the normal and tangential (frictional) forces in amorphous frictional media. We consider both the joint pdf of normal and tangential forces together, and the marginal pdf's of normal forces separately and tangential forces separately. A maximum entropy formalism is utilized for all these cases after identifying the appropriate constraints. Excellent agreements with both experimental and simulational data are reported. The proposed joint pdf (which appears new to the literature) predicts giant slip events at low pressures, again in agreement with observations.