Authors

Abstract

To promote the application of the discrete element method (DEM) in the research and development of soybean production equipment, reduce development costs, and improve testing efficiency, the contact parameters of soybean seeds in a discrete element environment were calibrated. A discrete element model of soybean seeds was established in EDEM software using a multi-sphere aggregation approach. The coefficient of restitution between soybean seeds and a Q235 steel plate was calibrated to 0.54 using a collision rebound test. The static friction coefficient between soybean seeds and the Q235 steel plate was calibrated to 0.34 through an inclined-plane sliding test, whereas the rolling friction coefficient was calibrated to 0.01 using an inclined-plane rolling test. The angle of repose of soybean seeds was determined to be 31 ° using the steel-box extraction method. Based on a quadratic regression orthogonal rotational combination design, a regression model describing the relationship between the soybean angle of repose and inter-particle contact parameters was established. The model was optimized through analysis of variance, and the optimal combination of inter-particle contact parameters was determined as follows: coefficient of restitution between seeds of 0.65, static friction coefficient between seeds of 0.55, and rolling friction coefficient between seeds of 0.04. Under these parameter conditions, the relative error of the angle of repose between the simulation and bench tests was 0.32%, demonstrating the accuracy of the calibrated contact parameters and the feasibility of the simulation method. The obtained results can provide a reference for selecting soybean seed contact parameters in discrete element simulations.

Abstract in Chinese

为了促进离散元法在大豆农业生产装备研发中的应用，降低研发成本，提高试验效率，对离散元环境下大豆的接触参数进行了标定。基于多球聚合模型，在EDEM软件中建立了大豆种子的离散元模型。通过碰撞弹跳试验、斜面滑移试验和斜面滚动试验，分别标定了大豆种子与Q235钢板间的碰撞恢复系数为0.54、静摩擦因数为0.34和滚动摩擦因数为0.01。通过堆积试验获得了大豆种子堆积角为31°。基于二次回归正交旋转组合试验，建立了大豆堆积角与种间接触参数的二阶回归模型。通过优化求解，得到种间接触参数的最佳组合为：种间碰撞恢复系数为0.65，种间静摩擦因数为0.55，种间滚动摩擦因数为0.04。该条件下仿真试验堆积角与台架试验堆积角的相对误差为0.32%，证明了试验测得的接触参数的准确性和仿真试验的可行性。试验结果可为大豆种子离散元仿真参数的选取提供参考。