针对油菜联合收获机脱粒分离过程中茎秆破碎率高、脱出物含杂率高的现实问题，本项目拟开展该脱离过程中油菜茎秆与脱粒元件间弹塑性碰撞机制及控制策略的研究。运用动态子结构方法，建立油菜茎秆与脱粒元件弹塑性碰撞子结构动力模型，推导相应的动力学控制方程；分析和描述油菜茎秆被脱粒元件撞击后瞬态应力波的产生和传播过程，探讨脱粒滚筒参数变化对撞击瞬态响应和瞬态波的影响；仿真分析、试验研究和高速摄影观察结合，揭示茎秆破碎机理，提出降低脱粒过程茎秆破碎率和提高油菜籽粒脱净率的有效措施。基于浮动式凹板筛技术和脱粒滚筒转速、喂入量自动可调技术，设计台架试验，验证油菜茎秆破碎机理，进行油菜联合收获机纵轴流式脱粒滚筒结构改进和参数优化。

The high crushing rate of stalks and impurity rate of extraction content is a practical and common problem in the threshing and separating process of current rape combine harvester. This project will focus on the elastic-plastic collision mechanism and its control strategies between rape stalks and threshing components. Using dynamic substructure method, the substructure dynamic model of elastic-plastic collision between rapeseed stalks and threshing components will be established, and the dynamic control equations will be deduced; The project analyses and describes the generation and propagation process of rapeseed stalks transient stress wave after the collision with threshing components, and the collision transient response and transient wave differences made by the parametric variation of threshing cylinder will be discussed; Combining with the simulation analysis, experimental study and high-speed photography observation, the mechanism of stalks broken will be revealed and the effective measures to decrease the stalks crushing rate and increase the threshing rate of rapeseed during threshing will be proposed．Based on the technology of floating concave sieve and the adjustability of threshing drum rotating speed and feeding amount, bench experiment will be conducted to verification the mechanism of rape stalks breaking, to improve the structure and optimize the parameters of rape combine harvester longitudinal axial-threshing drum.