Identification and Validation of Rolling Friction Models by Dynamic Simulation of Sandpile Formation

Abstract

Rolling friction plays an important role in the heap formation of granular materials. In this paper, three rolling friction models, which are incorporated into the discrete element method, are compared with simulation of sandpile formation in detail. The experiments were first implemented for cement particles to verify the reliability of simulated results. An approximate approach, which can be used to determine the friction coefficient between particles and between particles and a boundary, is also proposed. Then, numerical simulations parallel to the experiments were carried out by using the three rolling friction models. The simulated results are detailed and discussed compared with the experimental results. In addition, the rolling friction between the particles and boundaries was also studied through an example of a sphere moving on a horizontal plate with an initial translational velocity. The numerical results suggest that the rolling friction model described by the relative angular velocity can well reflect the rolling friction behavior and that the rolling friction tangential force has little effect on the simulated result.