Energetic Instability Unjams Sand and Suspension

TL;DR

This paper develops a comprehensive theory describing the elastic deformation of jammed states in granular and complex fluids, capturing key features like yield surfaces and phase transitions, with validation against experiments and simulations.

Contribution

It introduces a unified stress-strain relation for jammed materials, extending to magneto- and electro-rheological fluids, advancing understanding of jamming phenomena.

Findings

Derived a granular stress-strain relation capturing Coulomb yield surface

Generalized the theory to magneto- and electro-rheological fluids

Results align well with experimental and simulation data

Abstract

Jamming is a phenomenon occurring in systems as diverse as traffic, colloidal suspensions and granular materials. A theory on the reversible elastic deformation of jammed states is presented. First, an explicit granular stress-strain relation is derived that captures many relevant features of sand, including especially the Coulomb yield surface and a third-order jamming transition. Then this approach is generalized, and employed to consider jammed magneto- and electro-rheological fluids, again producing results that compare well to experiments and simulations.