Thermodynamics and Statistical Mechanics of dense granular media

TL;DR

This paper demonstrates that dense granular media at rest can be described using thermodynamic principles, with states characterized by few parameters and described by equilibrium distributions aligned with Edwards' statistical mechanics.

Contribution

It provides a detailed simulation-based validation that granular packs can be characterized thermodynamically and introduces a new thermodynamic parameter called 'configurational temperature.'

Findings

Granular materials can be described by few thermodynamic parameters.

States of granular media follow equilibrium distributions similar to Edwards' theory.

Derived an equation of state based on configurational temperature.

Abstract

By detailed Molecular Dynamics and Monte Carlo simulations %of a realistic model we show that granular materials at rest can be described as thermodynamics systems. First we show that granular packs can be characterized by few parameters, as much as fluids or solids. Then, in a second independent step, we demonstrate that these states can be described in terms of equilibrium distributions which coincide with the Statistical Mechanics of powders first proposed by Edwards. We also derive the system equation of state as a function of the ``configurational temperature'', its new intensive thermodynamic parameter.