Calibration of Dem Simulation of Cohesive Particles

DEM is a useful instrument to successfully design, optimise or simply analyse systems and equipment for granular materials in many applications where interparticle forces play a key role. In this paper, a study on the calibration of the parameters for the description of interparticle forces in DEM model is presented. Two different models for the interparticle forces have been used: a Hertz-Mindlin with Johnson-Kendall-Roberts (JKR) cohesive model and a Hertz-Mindlin with Linear cohesion model. By changing the model parameter and the time step, the simulations allow to evaluate the adhesion force between two particles. The calibrated value of the parameter can be chosen by a comparison between the force estimated, that is evaluated by means of the Rumpf-Molerus equation and that dependent on the Hamaker constant, with the simulation. However, it seems that both models are not suitable if a low time step is used. In fact, a small change of the model parameter could lead to a completely wrong estimation of the interparticle force