Shear rate dependent static friction between a wet granular layer and hard surface

Abstract

Prediction of static friction at sliding surfaces is having both fundamental and practical importance. In this article, a friction model was used to predict the static friction of wet granular material on hard surface. The model is based on the fact that granular particulates form capillary bridges to adhere with substrate, and rupture of these bridges results in friction. The model also considers the frictional strength of bridges, which develop during the application of shear velocity on sliding mass. The friction model is, in turn, validated with the experimental data of static friction vs. shear velocity of wet granular layers on a smooth rock surface. Scaling laws of frictional properties are also developed using regression analysis to justify the friction model.