Phase Transitions in Granular Packings

TL;DR

This paper models granular packings using a frustrated lattice gas, revealing two phase transitions related to dilatancy and percolation, with implications for understanding granular material behavior.

Contribution

It introduces a novel frustrated lattice gas model to describe contact networks in granular packings, identifying two key phase transitions and their correlation functions.

Findings

Identification of a spin glass transition at Reynolds dilatancy onset

Discovery of a percolation transition at lower densities

Proposal of dynamical experiments to test the model

Abstract

We describe the contact network of granular packings by a frustrated lattice gas that contains steric frustration as essential ingredient. Two transitions are identified, a spin glass transition at the onset of Reynolds dilatancy and at lower densities a percolation transition. We describe the correlation functions that give rise to the singularities and propose some dynamical experiments.