Research on coal wall parameter calibration and high precision model construction based on discrete element method

The accuracy of discrete element coal wall model significantly influences the characterization of coal-rock breaking mechanisms and equipment dynamic response in virtual prototype simulation. Based on coal-rock samples from Ordos Wenyu Mine of Yanzhou Coal Mining, key Tavares UFRJ parameters affecting particle compressive strength were identified through Plackett-Burman test and steepest ascent experiment. Breakage parameters were calibrated using optimal latin hypercube sampling (OLHS) and gaussian process regression (GPR). Hertz-Mindlin with Bonding parameters were then calibrated via uniaxial compression simulation. Model accuracy was verified through discrete element method-multi flexible body dynamics (DEM-MFBD) coupling simulation. Results indicate that D0, E Infinity, and Phi are the most significant parameters with influence rates of 38.5 %, 30.5 %, and 18.6 % respectively. The relative error between simulated and experimental particle compressive strength is below 4.56 %, while uniaxial compression simulation shows maximum relative error below 9.80 %. Comparing tri-axial load curves during shearer drum cutting, the maximum relative error of mean values between experimental and simulation data is 3.72 %, with maximum root mean square error (RMSE) of 4.60 %, outperforming traditional models and validating the model's accuracy and reliability for dynamic cutting process simulation.