DEM-based calibration of paddy soil contact parameters for improved soil-tool interactions

Abstract

Discrete element model (DEM) parameters are crucial for accurately predicting soil properties and disturbance levels. This study aimed to provide an efficient method for accurately determining DEM parameters for paddy soil. The Hertz-Mindlin and JKR contact models were used to simulate the paddy soil, and the Plackett-Burman, the Steepest Ascent, and the Box-Behnken tests were used to determine the DEM parameters. The accuracy of the established discrete element model was evaluated using actual slump test. The Plackett-Burman test results showed that the soil surface energy, soil-soil rolling friction coefficient, and soil-steel static friction coefficient had a significant impact on the total relative error between the simulation results and the test results. Box-Behnken test optimization results show that the soil surface energy, soil-soil rolling friction coefficient, and soil-steel static friction coefficient are 0.869 J.m², 0.109, and 0.651, respectively. Comparison with actual soil slump test results shows that the calibrated DEM model has an overall relative error of 5.59% and a coefficient of variation of 3.49%. This research can provide a theoretical basis and technical support for subsequent research on soil-machine interaction mechanisms.