Force chains and networks: wet suspensions through dry granular eyes

TL;DR

This paper investigates the connection between wet suspension flow and dry granular physics by simulating force networks, revealing similarities in force distribution and jamming behavior, which could improve rheological models.

Contribution

It demonstrates that force networks in wet suspensions closely resemble those in dry granular materials, providing new insights into suspension rheology near jamming.

Findings

Force networks in suspensions are similar to dry granular packings.

Jamming volume fraction and coordination number are comparable in both systems.

Contact force distributions in suspensions resemble those in granular materials.

Abstract

Recent advances in shear-thickening suspension rheology suggest a relation between (wet) suspension flow below jamming and (dry) granular physics. To probe this connection, we simulated the contact force networks in suspensions of non-Brownian spheres using the discrete element method (DEM), varying the particle friction coefficient and volume fraction. We find that force networks in these suspensions show quantitative similarities to those in jammed dry grains. As suspensions approach the jamming point, the extrapolated volume fraction and coordination number at jamming are similar to critical values obtained for isotropically compressed spheres. Similarly, the shape of the distribution of contact forces in flowing suspensions is remarkably similar to that found in granular packings, suggesting potential refinements for analytical mean field models for the rheology of shear thickening suspensions.