Abstract：In order to simulate the interaction more accurately between coal mining machinery and coal bulk materials, the parameters of coal particle model were optimized based on discrete element method (DEM) . Considering the irregular shape of coal particles, three kinds of particle models were established. A series of actual tests were carried out to measure the density of coal particle, the coefficient of restitution and the coefficient of static friction between coal and wear-resistant steel plate, the coefficient of restitution between coal particles. The accumulation angle obtained by actual test was taken as the response value, the coefficient of static friction and the coefficient of rolling friction among particles and the rolling friction coefficient between particle and wear-resistant steel plate were determined through the response surface method. Through the skateboard device, the optimal parameter combination was validated by comparing the simulation results with actual tests. Results showed that the numerical difference in accumulation angle of actual tests and simulation is 1.3 %, which improves the reliability of simulation results.

Keywords： discrete element method; repose angle; parameter optimization; image processing; response surface method