Authors

Abstract

At present, there is a lack of accurate discrete element simulation model and parameters in the optimization research and development of key components such as soil contact of seedbed preparation equipment in Huang Huai Hai double cropping production area, which hinders the optimization and improvement of equipment operation effect. In this paper, the discrete element method is used to study the interaction between soil-touching components and wheat straw-soil mixture to improve the performance of equipment. Firstly, the Hertz-Mindlin with JKR Cohesion contact model is selected for the wheat straw-soil mixture to calibrate the parameters. Then, the method of combining physical test and simulation test is used to calibrate the parameters, the cylinder lifting method is used to determine the buildup angle of wheat straw soil mixture, and the Plackett-Burman screening method and the steepest climbing test are used to determine the optimal combination range of soil-straw static friction coefficient, soil-straw dynamic friction coefficient and soil-soil dynamic friction coefficient contact model parameters. Using Box-Behnken test, the regression equation of the stacking angle of wheat straw soil mixture was obtained, and the variance and interaction effect of the regression model were analysed. The regression model was used to find the optimal solution in Design-Expert software with an angle of repose of 41.23°, which yielded a soil-straw static friction factor of 0.072, a soil-straw dynamic friction factor of 0.78, and a soil-soil dynamic friction factor of 0.068, with an angle of repose error of 1.43%, indicating that the contact model parameters are reliable, and the parameters can provide a reference and theoretical basis for the study of the key components of the seedbed preparation equipment such as touching soil in the Yellow and Huaihai Sea two-maturity zone.

Abstract in Chinese

当前我国黄淮海两熟制产区种床制备装备触土等关键部件优化研发过程中缺乏精确的离散元仿真模型与参数，阻碍了装备作业效果的优化提升。采用离散元法进行触土部件与小麦秸秆-土壤混合物互作研究是当前提升装备性能的重要方法，首先针对小麦秸秆-土壤混合物，应用EDEM软件，选用Hertz-Mindlin with JKR Cohesion接触模型，进行参数标定；然后采用物理试验与仿真试验相结合的方法进行参数标定，使用圆筒提升法进行小麦秸秆-土壤混合物堆积角的测定，使用Plackett-Burman筛选法与最陡爬坡试验，确定了土壤-秸秆静摩擦因数、土壤-秸秆动摩擦因数、土壤-土壤动摩擦因数接触模型参数最优组合范围，使用Box-Behnken试验，得到了小麦秸秆-土壤混合物堆积角的回归方程，并进行了回归模型方差与交互效应分析；接着应用Design-Expert软件中参数优化模块，以堆积角为41.23°为目标，通过回归模型寻找到了最优解，土壤-秸秆静摩擦因数0.072、土壤-秸秆动摩擦因数0.78、土壤-土壤动摩擦因数0.068，堆积角误差为1.43%，说明接触模型参数较为可靠，参数可以为研究黄淮海两熟制产区种床制备装备触土等关键部件提供参考与理论依据。