Abstract: In order to accurately establish the discrete element model of moist sugarcane compound fertilizer, reasonably set the simulation parameters, and improve the accuracy of the simulation results of fertilizer particle dynamics, the angle of repose was used as the response value, and the sugarcane compound fertilizer with different moisture content was tested. The ternary regression equation of moisture content and angle of repose was established by the unloading bin method, and the coefficient of determination was 0.99. HertzMindlinwith JKR was used as the bonding model, and JKR surface energy, the shear modulus of sugarcane compound fertilizer, the static friction coefficient between sugarcane compound fertilizer and stainless steel, the static friction coefficient between sugarcane compound fertilizers, and the coefficient of restitution between sugarcane compound fertilizers were selected from nine initial parameters. Then the angle of reposediscrete element parameters model was established, the Pvalue of the model was less than 0.01, the coefficient of variation was 6.35%. Finally, through the simulation angle of repose test of the optimal parameter combination under different moisture content, the relative error between the simulation results and the physical angle of repose test was less than 7.66%, which verified that the calibration results and research methods of sugarcane compound fertilizer parameters with different moisture contents were reasonable and reliable. The research results could provide reference for the simulation research of sugarcane fertilization mechanical dynamics based on discrete element method.

Key words: moist sugarcane compound fertilizer, moisture content, discrete element, parameter calibration

摘要： 为能准确建立潮湿甘蔗复合肥的离散元模型，合理设置仿真参数，提高肥料颗粒动力学仿真结果的准确性，以休止角为响应值，对不同含水率的甘蔗复合肥进行试验研究。通过卸料仓法建立含水率与休止角的三元回归方程，决定系数为0.99；基于HertzMindlin with JKR粘结模型，通过PlackettBurman试验、爬坡试验和BoxBehnken试验从9个初始参数筛选出JKR表面能、甘蔗复合肥剪切模量、甘蔗复合肥与不锈钢静摩擦系数、甘蔗复合肥间静摩擦系数、甘蔗复合肥间恢复系数5项显著性参数，并建立休止角—离散元参数模型，模型P值小于0.01，变异系数为6.35%；最后，通过对不同含水率下的最佳参数组合进行仿真休止角试验，仿真结果与物理休止角试验的相对误差小于7.66%，验证不同含水率的甘蔗复合肥参数标定结果和研究方法是合理可靠的。研究结果可为基于离散元法的甘蔗施肥机械动力学仿真研究提供参考。

关键词: 潮湿甘蔗复合肥, 含水率, 离散元, 参数标定