High-stress impact–abrasion test by discrete element modeling

Abstract

This work presents a discrete element model (DEM) of the impeller–tumbler wear test in order to investigate high-stress impact–abrasion mechanisms on steel plates with the use of abrasive granite particles. A DEM calibration procedure of the granite particles is first performed to set particle-scale DEM parameters such as particle shape, density and frictions. The simulations of the impeller–tumbler wear test showed good qualitative results with experimental observations. Simulation results demonstrate that edges of the tested steel plate samples are first abraded, as in the experiments, and a linear increase in abrasion energies cumulated with time on the steel plates is obtained which is in accordance with the linear time evolution of sample mass loss in the experiments. Simulations shed light on the particle flow and particle–wall contact behavior which was impossible to observe experimentally. Local investigations of particle–wall contacts show an exponential decay of normal contact forces classically found for static granular materials when forces are above the mean contact force. Also, tangential contact forces distribution follows an exponential decay for forces above their mean force. This work demonstrates that the exponential decay of large contact forces is a robust feature even for a dynamic and loose granular system which is a novelty. Finally, probability density functions of normal and tangential abrasion energies are found to follow exponential decays for energy data above their mean values which is for the first time observed.