Rapid calibration method for discrete element simulation parameters of columnar granular organic fertilizer with variable moisture content

The variable moisture content of granular organic fertilizers leads to poor applicability of discrete element simulation parameters, making quick calibration of these parameters a challenge. Therefore, a method was proposed to quickly calibrate columnar granular organic fertilizers' DEM parameters with varying moisture content. Initially, a method for measuring the angle of repose of irregular piles formed by columnar granular organic fertilizers was proposed. Then, a prediction model between moisture content (7.8 % to 18.5%) and DEM parameters was developed using the Plackett-Burman test, the Steepest Ascent test, and the Box-Behnken test. Experimental results show that the proposed method for measuring the angle of repose has an average relative error of 2.88 %, which is lower than the conventional angle of repose measurement method. The simulation angles of repose predicted by the proposed DEM parameter model had an average relative error of 4.28 %, indicating that the model is stable and reliable.