Rapid acquisition method of discrete element parameters of granular manure and validation

It is not easy to obtain the numerical simulation model of organic fertilizer quickly and accurately due to the wide range of moisture content of machine-applied bulk manure. This paper proposes a method of obtaining discrete element simulation parameters by measuring bulk manure's moisture content according to the two edge contours of the stacking angle and the image processing method to reduce the measurement error. With Hertz-Mindlin with JKR as the model, the Plackett-Burman test is used to screen the DEM parameters that significantly impact the simulation test's stacking angle. The Climbing and Box-Behnken tests establish a prediction model for the stacking angle of moisture content and DEM parameters. The funnel and probe methods are used to verify the stacking angle of manure. The comparison results showed that the average relative error is less than 4.30%. The mechanical properties' comparison test shows that the Displacement-Load change trend is consistent, and the average relative load error is 12.1%. The validation results of the manure box indicate that the average torque error is 11.73%. The above results show that the prediction model established is stable and reliable. By measuring the moisture content, the DEM parameters of granular manure can be quickly obtained, improving fertilization machinery's design and optimization efficiency.