Authors

Abstract

An optimization method based on a regression model was established by combining physical experiments, and an extended distinct element method (EDEM) simulation was proposed to address the difficult problem of obtaining the contact characteristic parameters used in the discrete element method (DEM) model of quinoa grains and for calibrating the parameters of the quinoa DEM model. The Plackett-Burman test was designed using Design-Expert software to screen the parameters of the quinoa DEM model, and the quinoa-quinoa static friction coefficient, quinoa-polylactic acid (PLA) static friction coefficient and quinoa-quinoa rolling friction coefficient were found to have significant effects on the repose angle. The optimal value intervals of the parameters with a significant impact on the repose angle were determined using the steepest ascent test. A regression model of the repose angle and the parameters with a significant impact on the repose angle was then established with the Box-Behnken design and further optimized, and the combination of optimal parameters was as follows: 0.26 for the quinoa-quinoa static friction coefficient (E), 0.38 for the quinoa-PLA static friction coefficient (F), and 0.08 for the quinoa-quinoa rolling friction coefficient (G). Lastly, the optimal combination was used in the verification performed by the DEM simulation, and the error between the simulated repose angle and the target repose angle was 0.86%. These findings indicated that it was feasible to use the response surface optimization to calibrate the parameters required for quinoa DEM simulation and that the combination of optimal parameters can provide a reference for selecting the characteristic contact parameters used in quinoa DEM simulation.

Abstract in Chinese

针对藜麦离散元仿真模型接触参数难以直接获取的问题，提出一种结合物理试验和EDEM仿真试验建立回归模型进行寻优的方法，对藜麦离散元仿真模型参数进行标定。应用Design Expert软件设计Plackett-Burman试验对藜麦离散元模型参数进行筛选，得到藜麦-藜麦静摩擦系数、藜麦-PLA静摩擦系数和藜麦-藜麦滚动摩擦系数对休止角影响显著；通过最陡爬坡试验确定显著性参数的最优值区间，然后根据Box-Behnken设计结果建立休止角与显著性参数的回归模型并对其进行优化，得到显著性参数的最佳组合为：藜麦-藜麦静摩擦系数为0.26、藜麦-PLA静摩擦系数为0.38、藜麦-藜麦滚动摩擦系数为0.08。最后将最佳参数组合进行离散元仿真验证，仿真休止角与目标休止角的相对误差为0.86%，表明应用响应面优化标定藜麦离散元仿真中所需的参数是可行的；标定所得的最佳参数组合可为藜麦离散元仿真接触参数的选取提供参考。