PARAMETERS CALIBRATION OF DISCRETE ELEMENT MODEL FOR CRUSHED CORN STALKS

Abstract

For the problem of lacking reliable parameters during simulation analysis of the crushed corn stalk (CCS) micro-comminution process with gas-solid coupling method, the simulation parameters are calibrated using a combination of physical measurements and virtual experiments with CCS as the research object. The intrinsic parameters of CCS are obtained by physical experiment, and the stacking test is carried out by cylinder lifting method, and the actual angle of repose(AoR) is obtained as 44.12° by fitting the boundary line with Matlab software; the discrete element model of CCS is established, and the virtual stacking test is carried out by EDEM software; CCS-CCS dynamic friction coefficient, CCS-CCS static friction coefficient and JKR (Johnson-Kendall-Roberts) surface energy are identified as the parameters with significant effects on the AoR by Plackett-Burman test; the steepest climb test is leveraged to determine the center of response surface analysis; the quadratic polynomial regression model of the simulation parameters and the AoR is established by the Box-Behnken test using the AoR as the evaluation index, and the optimal combination of the significant parameters are obtained as follows: the CCS-CCS dynamic friction coefficient is 0.55, the CCS-CCS static friction coefficient is 0.14, and the JKR surface energy is 0.12; the AoR verification test is conducted based on the optimal combination of the significant parameters The results show that the AoR of the CCS is 43.82°, which is 0.68% of the actual AoR, indicating that the parameter combination is reliable. The data obtained in this research can provide corresponding simulation parameters for CCS discrete element simulation and the development of straw micro-crushing equipment.