The effect of liquid viscosity on sliding friction coefficient of wet granular materials

Mojgan Aliasgari,Nahid Maleki-Jirsaraei,Shahin Rouhani,M.A Aguirre,R Soto,S Luding,L.A Pugnaloni

doi:10.1051/epjconf/202124908003

Mojgan Aliasgari, Nahid Maleki-Jirsaraei + Show 5 more

Open Access

https://doi.org/10.1051/epjconf/202124908003

Copy DOI

Abstract

The mechanical properties of wet granular materials are different to those of dry granular matter. If the wet granular medium is not completely saturated, the capillary bridges form and the surface tension changes the elastic properties of the medium. We studied the sliding friction of a sledge over wet granular media and found that surface tension and viscosity have crucial effect on the dynamic friction coefficient of the wet granular media. Higher the viscosity of the interstitial liquid results in higher dynamic friction coefficient. Furthermore, viscous interstitial liquid shows time dependency behaviour. Viscosity makes the friction coefficient to increase since causes more the energy loss.

Highlights

Energy loss due to friction is a well-known characteristic of granular materials
We study the effects of interstitial liquids, its surface tension and its viscosity on the sliding friction of wet granular media in an unsaturated regime
We first measured the lateral force versus time, F measured by the load cell when the slider moves with a constant velocity on the wet granular media, we repeat this procedure for the granular media made by the different interstitial liquids(Table1)

Summary

Introduction

Energy loss due to friction is a well-known characteristic of granular materials. The addition of a liquid can help to reduce this issue. The crucial effect here is that the liquid forms a capillary bridge between the grains, acting as a cohesive force, which results in a larger modulus and large angle of repose of a granular heap [3]. Increasing the cohesion of the partially wet granular system leads to less shear-thinning behaviour [4]; viscosity of the interstitial liquid can affect the cohesion of such systems. We study the effects of interstitial liquids, its surface tension and its viscosity on the sliding friction of wet granular media in an unsaturated regime. We measure the lateral force that resists the motion of a slider and calculate the dynamic coefficient friction as a function of the surface tension and viscosity of the interstitial liquid. An independent penetration hardness test was applied which confirms the friction response

Methods

Results

Conclusion