Investigations into calibration for discrete element modelling of granular materials

This paper examines numerous methods to calibrate dynamic simulations of particulate flows of free flowing and cohesive granular materials. Discrete element method (DEM) has proven to be a reliable and effective tool to model the behaviour of granular matter. There are a number of microscopic mechanisms that influence the macroscopic and bulk behaviour of granular flow. To accurately determine the equivalent microscopic parameters and calibrate the DEM simulations to reflect realistic dynamics behaviour, various bench-scale experiments were performed to determine the bulk characteristics, such as the angle of repose and hopper discharge behaviour. Parameters such as static friction coefficients, rolling friction coefficients, shear modulus, coefficients of restitution, particle geometry (e.g. particle size and shape) and cohesive forces due to liquid bridges were investigated. A series of standard bulk material tests were conducted to determine the particle density, bulk density, particle size distribution and approximate the static friction coefficients, cohesive stress and coefficient of restitution for the DEM simulations. The DEM simulations were validated against bench-scale experimental investigations using a high-speed camera to capture the granular flow to quantify the DEM input parameters and fine tune parameters accordingly to obtain equivalent dynamic behaviour.