Effect of boundaries on the force distributions in granular media

TL;DR

This paper investigates how boundary conditions influence force distributions in 2D granular packings, revealing that boundary geometry significantly alters the weight distribution while the interparticle force distribution remains robust.

Contribution

It distinguishes between experimentally measured weight distributions and force distributions, showing boundary geometry's impact on the former in granular media.

Findings

Boundary geometry drastically changes weight distribution {\

Force distribution P(f) remains robust despite boundary variations.

Manipulating boundaries can significantly alter the measured weight distribution in granular packings.

Abstract

The effect of boundaries on the force distributions in granular media is illustrated by simulations of 2D packings of frictionless, Hertzian spheres. To elucidate discrepancies between experimental observations and theoretical predictions, we distinguish between the weight distribution {\cal P} (w) measured in experiments and analyzed in the q-model, and the distribution of interparticle forces P(f). The latter one is robust, while {\cal P}(w) can be obtained once the local packing geometry and P(f) are known. By manipulating the (boundary) geometry, we show that {\cal P}(w) can be varied drastically.