# Shear Thickening of Dense Suspensions: The Role of Friction

## TL;DR

This paper investigates how inter-particle friction affects shear thickening in dense suspensions, revealing that the effective friction coefficient remains largely unaffected by microscopic friction variations, which aligns with recent theories and experiments.

## Contribution

It introduces a model linking effective friction to jamming distance and shear stress, showing insensitivity to microscopic friction in dense suspensions.

## Key findings

- Effective friction coefficient is insensitive to interparticle friction.
- Proposed expressions relate effective friction to jamming and shear stress.
- Results align with recent theoretical and experimental findings.

## Abstract

Shear thickening of particle suspensions is characterized by a transition between lubricated and frictional contacts between the particles. Using 3D numerical simulations, we study how the inter-particle friction coefficient influences the effective macroscopic friction coefficient and hence the microstructure and rheology of dense shear thickening suspensions. We propose expressions for effective friction coefficient in terms of distance to jamming for varying shear stresses and particle friction coefficient values. We find effective friction coefficient to be rather insensitive to interparticle friction, which is perhaps surprising but agrees with recent theory and experiments.