Authors

Abstract

The contact parameters setting determines the accuracy of discrete element method (DEM) simulation analysis, while there is a lack of research on contact parameters of green onion seed. In this paper, the physical parameters of green onion seeds were measured by experiment, and the DEM parameters were calibrated by simulation. Based on EDEM software, the Hertz-Mindlin no-slip model was used to create the particle model of green onion seeds that takes on the shape of peltate with the irregular surface, and the repose angle was measured by the measurement method of lifted cylinder. Plackett-Burman test was designed to screen the significance of parameters, and the optimal range of significance parameters was further determined through the steepest climbing test. Then the regression model of seeds repose angle was obtained by Box-Behnken test and the optimal parameter combination was calculated: the static friction factor between seeds was 0.424, the rolling friction factor was 0.085, the static friction factor between seeds and steel was 0.310. The optimized repose angle in the simulation had an overall relative error of 0.54%, indicating that the contact parameters of the calibrated green onion seed had high accuracy.

Abstract in Chinese

离散元法（DEM）仿真分析的精度取决于接触参数的设置，而目前缺乏对大葱种子接触参数的相关研究。因此，本文通过实验测量了大葱种子的物理参数，并通过仿真对其离散元参数进行了标定。基于EDEM软件，采用Hertz-Mindlin无滑动接触 模型，建立了大葱种子呈盾形且表面不规则的颗粒模型，并采用圆筒提升法测量堆积角。通过Plackett-Burman试验筛选参数的显著性，并使用最陡爬坡试验进一步确定显著性参数的最佳范围。然后通过Box-Behnken试验得到大葱种子堆积角的回归模型，并计算出最优参数组合:大葱种子间静摩擦系数为0.424，大葱种子间滚动摩擦系数为0.085，大葱种子与钢板静摩擦系数为0.310。经过优化后的仿真堆积角与实际数值的相对误差为0.54%，说明标定出的大葱种子接触参数具有较高的精度。