Authors

Abstract

To address the lack of accurate and reliable straw models for simulating rice straw cutting, this study uses rice straw as the research object and constructs a discrete element model of straw using EDEM software to calibrate and optimize the bonding parameters. First, the physical parameters of rice straw, including its geometric dimensions, density, collision recovery coefficient, and friction coefficient, were measured. For the bonding model parameters, a preliminary experiment was conducted to determine the range of bonding parameters, and the significance of each bonding parameter was analyzed using Plackett-Burman experiments to identify parameters with a significant impact on straw shear force. Then, a steepest climb test was conducted to determine the optimal combination of bonding parameters. Finally, a Box-Behnken simulation experiment was performed on the optimization interval, and a regression equation was established and solved to obtain the optimal parameter combination. The results show that the normal bonding stiffness, tangential bonding stiffness, and bonding radius have a significant impact on the straw shearing model. The optimal combination is 3.092×10¹⁰ Pa, 4.452×10¹⁰ Pa, and 0.496 mm. The established rice straw model is reliable and stable through multiple simulation experiments. This study provides an accurate and efficient method for optimizing the structure and motion parameters of rice straw crushing blades.

Abstract in Chinese

为解决水稻秸秆切断模拟过程缺乏准确可靠的秸秆模型，该研究以水稻秸秆为研究对象，利用EDEM软件构建秸秆离散元模型，对粘结参数进行标定与优化。首先对水稻秸秆外形几何尺寸、密度、碰撞恢复系数、摩擦系数等物理参数进行了测定；针对粘结模型参数，先通过预试验确定模型粘结参数范围，并采用Plackett-Burman试验对各项粘结参数显著性进行分析，筛选出对秸秆剪切力影响大的参数，然后进行最陡爬坡试验，确定粘结参数最优组合所在区域范围，最后对优化区间进行Box-Behnken仿真试验，建立回归方程，求解获得最优参数组合。结果表明：法向粘结刚度、切向粘结刚度、粘结半径对秸秆剪切模型影响显著，最优组合为3.092×1010Pa、4.452×1010Pa和0.496mm，并通过多次仿真试验验证建立的水稻秸秆模型可靠稳定，该研究可为优化水稻秸秆粉碎刀具结构和运动参数提供了准确高效方法。