Experimental and DEM studies on the normal coefficient of restitution of grain-block systems in the presence of thick and thin water layers under low-velocity impacts

Abstract

In the present work, an experimental study was carried out investigating the influence of water at the contacts of grain-block systems subjected to low-velocity impacts using two different configurations as (i) impacts in the presence of a thick liquid layer with water thickness similar to that of the grain diameter and (ii) impacts in the presence of thin liquid layer in the form of water droplets. A parametric study was performed to understand the major contributing mechanisms in these impact tests. Additionally, part of the experimental data, in terms of the normal coefficient of restitution, was used to calibrate a numerical model using the discrete element method (DEM). The DEM analyses provided further insights into the impact behavior of grain-block systems, and an attempt was made to back-calculate the yield velocity and contact forces, combining the numerical results with analytical expressions.