Simulation of surface abrasion in LAMMPS

Abrasion is a particular form of particle attrition in which a particle changes in shape by becoming smoother over time through the preferential removal of protrusions on the particle’s surface. Fines are produced by abrasion which are much smaller than the particle’s size. Abrasion plays a significant role in industrial applications and processing operations, as does attrition more broadly. DEM simulations have contributed greatly to our understanding of granular materials behaviour in recent years; however, simulations of abrasion in DEM are very few and are mostly application-based. In view of these considerations, a novel approach is presented for modelling abrasion in DEM. An immobile surface is discretized by a set of points and is abraded by a non-deformable particle. When the pressure on the surface overcomes a threshold, abrasion starts which is captured in the simulation by displacing points along the normal to the surface. Thus, the surface changes in profile during the simulation. This model can be used to simulate both the abrasion caused by solid particle impact and abrasion during scratch tests for which the Archard model is usually employed. The implementation of this novel method in LAMMPS is presented in the simple case of a flat surface. The more complex case of the abrasion of curved surfaces is discussed.