A systematic approach to DEM material model calibration

As industry increases its use of DEM for simulation of particulate handling and processing operations, attention is increasingly focused on model calibration and methods for dealing with scaling and multi-scale modeling issues. Here we examine the basis for choosing a DEM model relative to the bulk particulate material and the process being simulated, and outline strategies for calibrating DEM models against measured particle and bulk properties and behavior. A DEM model is a combination of the particle inertial properties (size, shape, density) and mechanical properties (stiffness, elasticity, plasticity) and interaction terms between particles and other objects - particles or boundary surfaces. The latter depends on the choice of contact models which may include parameters such as friction, restitution coefficient and cohesion for example, and the body force model, usually gravity, but also could include fluid drag, electrostatic force, and magnetic force, and so on. Together these properties and parameter values form what we describe as the DEM material model. The choice of DEM material model depends on the focus and objectives of the simulation. In bulk transport problems where the objective is to predict local mass flow rates and load transfer to boundary surfaces, the choice and calibration of the material model is dependent only on bulk flow characteristics. The paper describes a system that includes basic physical experiments and an optimization procedure involving DEM simulation using the EDEMTM software package to calculate the DEM material properties necessary for simulations to produce results within a suitable accuracy range.