Authors

Abstract

Dynamic soil behavior at the contact interface during transplanting makes it difficult to ensure transplanting quality. To solve this problem, the Hertz-Mindlin with bonding contact model was used to calibrate the parameters of soils in Inner Mongolia. Based on the response surface design principle, four-factor and three-level tests were performed using the repose angle as an evaluation index, and the following influence factors were considered: the soil-soil restoration coefficient, the soil-steel restoration coefficient, the soil-steel static friction coefficient and the soil-steel static friction coefficient. A regression model was analyzed, and an optimization procedure yielded the following optimum combination of parameters: a soil-soil restoration coefficient of 0.45, a soil-steel restoration coefficient of 0.35, a soil-steel static friction coefficient of 0.85 and a soil-steel rolling friction coefficient of 0.13. This optimal combination was used to simulate the soil at the contact interface. The particle dynamic behavior and soil particle mass flow were used to analyze the soil dynamic behavior, showing that the average mass flow during the gradual opening of the duckbilled planter tends to increase over time; when the duckbilled planter gradually leaves soil, the contact interface of soil particles in the corner of the duckbilled planter unit causes a reduction in the fluctuation range of the soil mass flow, which exhibits a wave-like change. After the duckbilled planter has left soil, the contact interface of the soil changes tends to stabilize. The duckbilled planter-soil discrete element simulation model was verified. The results of this study provide a reference for the optimal design of a duckbilled planter structure.

Abstract in Chinese

为解决栽植器与接触界面土壤的动态行为造成土壤回流，使栽植质量难以保证等问题，利用Hertz-Mindlin with Bonding 模型对内蒙地区移栽环境下田间土壤进行参数标定，基于响应面法，分别以土壤-土壤恢复系数、土壤-钢恢复系数、土壤-钢静摩擦系数和土壤-钢滚动摩擦系数为试验因素，进行四因素三水平的正交试验，对回归模型进行了分析，最终得到最佳参数组合为土壤-土壤恢复系数0.45、土壤-钢恢复系数0.35、土壤-钢静摩擦系数0.85和土壤-钢滚动摩擦系数0.13；根据最优组合，模拟栽植状态下接触界面的土壤颗粒动态变化行为，进行土壤颗粒质量流量分析，结果表明鸭嘴式栽植器逐渐打开过程中的平均质量流量随着时间的增加呈逐渐增加的趋势，当鸭嘴式栽植器逐渐离开土壤时，鸭嘴式栽植器单位转角内与不同土壤颗粒接触界面变化，土壤质量流量的波动范围较小，呈现波浪式的变化，最终当鸭嘴式栽植器离开土壤，接触界面的土壤质量变化趋于稳定。验证了鸭嘴式鸭嘴式栽植器-土壤离散元仿真模型的正确性，并研究栽植过程中接触土壤的动态变化，为鸭嘴式栽植器结构的优化设计提供参考。