全膜双垄沟机械化垄体成型、膜土耦合过程解析及其种床高效构建方法

The furrow sowing with whole plastic-film mulching on double ridges has been widely used in the arid region of northwest China, because it can resist drought and increase production. So the mechanical building the seedbed is an inevitable trend in farming. At present, the mechanized farming process and method of ridge forming, film and soil coupling with whole plastic-film mulching on double ridges is unsharpness, and the key operation mechanism design theory was lacked. which caused the seedbed mechanical building failure was the core problems of production system function weaken and production mechanization processes blocked. Through the research of typical seedbed physical and mechanical properties of whole plastic-film mulching on double ridges, so the seedbed building failure characteristic and its control strategy was ascertained. Under the theory of granular dynamics and soil dynamics, analyzing the motion behavior of cutting bed soil with farming parts, and explaining the irregularity ridge forming principle of mechanized farming. By using DEM-MBD coupling theory and nonlinear finite element method, the multi-objective optimization model of film mulching and soil covering mechanism was established, which expound the dynamic operation mechanism of film mulching and soil covering. Application of high-speed video technology and the gas-solid coupling theory, in order to reveal film and soil coupled transient characteristics in seedbed building process, meanwhile, explore the best constraint condition of covering and rolling soil. Accordingly, which create the high-performance ridging and film-soil coupling combined mechanism, and also improve the theory of seedbed mechanical building with whole plastic-film mulching on double ridges. The results will effectively promote the entire mechanization level of production system of whole plastic-film mulching on double ridges, which have great significance to ensure agricultural productivity and food security in arid northwest China.

全膜双垄沟播技术抗旱、增产被中国西北旱区大面积推广，实现其种床机械化构建是必然趋势。目前全膜双垄沟种床垄体成型机理与其膜土耦合机制不明晰，关键作业机构设计理论缺失，致使覆膜异形双垄种床机械化构建失效成为触发其生产系统功能弱化、生产环节机械化受阻的核心难题。通过研究全膜双垄沟典型种床物理机械特性，探知种床失效特征及其控制策略；结合散体动力学和土壤动力学理论，分析耕作部件切削种床土壤运动行为，探明异形垄体耕作成型机理；借助DEM-MBD耦合理论及非线性有限元法，建立覆膜覆土机构多目标优化模型，阐明机械化覆膜覆土动态作业机理；应用高速摄像技术与气固耦合理论，揭示种床构建中膜土耦合瞬时特征，探求最佳覆土镇压协同约束条件。据此，创制高性能起垄、覆膜覆土组合机构，形成全膜双垄沟种床机械化高效构建方法及理论。研究结果将有效提升全膜双垄沟生产系统全程机械化水平，对保障西北旱区农业生产力及粮食安全意义重大。

全膜双垄沟播技术抗旱、增产被中国西北旱区大面积推广，实现其种床机械化构建是必然趋势。目前，全膜双垄沟种床垄体成型机理与其膜土耦合机制不明晰，关键作业机构设计理论缺失，致使覆膜异形双垄种床机械化构建失效成为触发其生产系统功能弱化、生产环节机械化受阻的核心难题。本项目研究围绕全膜双垄沟种床机械化构建关键技术与装备，开展全膜双垄沟覆膜种床物理机械特性、水热效应数值模拟及其结构优化研究；建立种床机械化旋耕起垄、覆土、镇压相关离散元仿真理论与模型；以此为据完成全膜双垄沟种床机械化构建过程中旋耕起垄、覆土、镇压装置的设计研究、流场模拟及工作参数优化。项目研究成果阐明了起垄覆膜条件下不同类型耕作部件、覆膜装置与种床土壤的相互作用关系研究，揭示了全膜双垄沟机械化覆膜覆土动态协同作业机理，创制了横腰带覆土式全膜双垄沟覆膜联合作业机和全膜双垄沟双幅覆膜覆土联合作业机，形成了全膜双垄沟种床机械化高效构建理论与方法。