Authors

Abstract

To address the limited research on the material properties of ruminant protein supplement feed pellets and the lack of an accurate calibration framework for discrete element method (DEM) contact parameters, which constrains the optimization of related mechanical equipment, this study investigated both the fundamental physical and contact characteristics of protein supplement pellets. A DEM-based particle model was established, and the angle of repose was selected as the evaluation index. The Plackett Burman design was employed to identify the primary influencing factors, followed by a steepest ascent test and Box Behnken design to develop a regression model for parameter optimization and calibration. The results indicated that when the static friction coefficient, rolling friction coefficient, and restitution coefficient between particles were set to 0.52, 0.03, and 0.37, respectively, the restitution coefficient between particles and materials, as well as the static and rolling friction coefficients between particles, had significant effects on the angle of repose. The optimal parameter values were determined to be 0.45, 0.55, and 0.05, achieving the theoretical optimum. Validation experiments showed that the average deviation between the calibrated and measured angles of repose was 0.92%, demonstrating a high level of agreement between simulation and experimental results. The findings provide a reliable theoretical reference and parameter basis for the optimization of processing, conveying, and key component design in ruminant protein supplement feed machinery.

Abstract in Chinese

针对反刍动物蛋白补充饲料颗粒物料特性研究不足、离散元仿真接触参数标定体系不完善、难以为相关机械装备优化设计提供可靠理论与数据支撑的问题，本研究以蛋白补充颗粒饲料为研究对象，开展了基本物理特性与接触特性测试。基于离散元方法构建颗粒仿真模型，以休止角为评价指标，采用Plackett Burman试验筛选主要影响因素，进一步结合最陡爬坡试验与Box Behnken设计建立回归模型，实现了仿真接触参数的优化标定。结果表明，当颗粒与材料的静摩擦系数、滚动摩擦系数及颗粒间碰撞恢复系数分别为0.52、0.03和0.37时，颗粒与材料的碰撞恢复系数以及颗粒间静摩擦系数、滚动摩擦系数对休止角的影响显著；其最优取值分别为0.45、0.55和0.05，模型达到理论最优解。验证试验结果显示，标定后休止角与实测值的平均误差为0.92%，表明仿真结果与试验结果具有较高一致性。研究成果可为反刍动物蛋白补充饲料在加工、输送及相关机械关键部件的优化设计提供可靠的理论参考与参数支持。