Measurement and calibration of the discrete element parameters of wet bulk coal

To simulate the interactions between the coal mining machinery and bulk coal accurately, the parameters of wet bulk coal were calibrated using the discrete element method (DEM). The influence of discrete element parameters on particle stacking angle was obtained by Plackett-Burman (PB) test. The calibration and verification of these parameters were carried out based on JKR (Johnson-Kendall-Roberts) model. During the calibration, a series of experiment were carried out; the repose angle obtained by the actual test was taken as the response value. The Box-Behnken design (BBD) based on the principle of response surface method (RSM) was applied in calibration. The numerical difference between those repose angles of actual tests and simulation was less than 4.70%, which improved the reliability of the simulation results. The optimal parameter combination could provide a reference for the reasonable selection of simulation parameters of the wet bulk coal using the EDEM software.