General Method for Discrete Element Parameters Calibration of Goat Manure with Different Moisture Contents

To solve the problem that the calibration method of discrete element simulation parameters was not universal and practical due to the large difference in moisture content of livestock and poultry manure, the discrete element parameters of goat manure with different moisture contents were studied with the resting angle as the response value. The moisture content - resting angle model was established with the cylinder lifting method, and the correlation coefficient was 0. 999 9. Based on the particle size distribution of goat manure, EDEM particle models of four kinds of particle sizes were established, and Hertz-Mindlin with JKR was used as the bonding model. Three significant parameters of JKR surface energy, rolling friction coefficient, and static friction coefficient between particles were selected from ten parameters by the Plackett-Burman test, climbing test, and Box-Behnken test. Then the resting angle-discrete element parameters model was established. The P-value of the model was less than 0. 000 1, and the relative error was less than or equal to 2. 42% . The moisture content-discrete element parameters model was constructed based on the moisture content resting-angle model and the resting angle discrete element parameters model. The engineering verification test with the side plate lifting method was conducted, and the relative error was less than or equal to 5. 37% . The results showed that the moisture content can be used to predict the discrete element parameters of goat manure directly, and the method had fast prediction speed with high accuracy at the same time. The research results provide a general and reliable method for determining discrete element parameters of goat manure. © 2022 Chinese Society of Agricultural Machinery. All rights reserved.