全喂入花生摘果动态损伤机理与低损伤摘果机构研究

China's annual output of peanut pods is about 17 million tons, accounting for the 50% of all oil crops. However, the 5% of the peanut pods were damaged during the threshing, it caused the direct or indirect losses. Mechanical threshing can lead to breakage of peanut shell and the peanut kernels exposed. The peanut without intact shell would be picked out or gradually deteriorate, and damage the storage. In this project, the physical mechanical properties of pods and plants would be obtained through the test. And the mechanism of the pod mechanicaldamage would be studied with the discrete element and finite element. The peanut threshing test devices would be developed. Besides, the distribution, movement, posture of plants and pods and the separation between pods and stems would be observed with the high speed photography during the threshing. So the influence factors and dynamic changing principle would be analyzed. Based on the collision theory, the contacting collision, stress and breakage process of peanut pods and threshing components would be analyzed. And the dynamic damage mechanism in the peanut threshing process would be revealed by building the dynamic model. Determine the optimal peanut threshing principle and build new mechanism, explore the effect of key threshing components parameters on peanut threshing damage by the virtual reality system, and optimize the structure and parameters. Finally, develop the full-feeding peanut thresher prototype, which will be tested and improved. This project could be used to improve the technology level of peanut thresher in China and then solve the problem of peanut threshing, it also could provide theoretical basis for the design of relative harvesting machinery.

我国年产花生1700万吨，占油料作物50%。然而，花生荚果的5%因摘果损伤而直接或间接损失。机械摘果导致花生果壳破损和花生米离壳，失去完好外壳的花生被直接选出或逐渐劣变且危害储藏。项目通过系列试验研究花生荚果及植株等物理机械特性；采用离散元与有限元方法研究花生荚果损伤特性；研制轴流与切流式全喂入花生摘果试验台并借助高速摄影仪观察摘果过程中植株和荚果分布、运动、姿态和果茎分离动态过程，分析其影响因素和规律；基于碰撞力学等理论分析花生荚果与摘果部件接触碰撞、受力和破损过程，建立相应动力学模型，揭示花生摘果过程中动态损伤机理；确定花生摘果最佳原理并构建新型机构，通过虚拟样机仿真分析探求摘果关键部件参数对花生摘果损伤影响，优化结构和参数；分别研制出低损伤轴流式和切流式全喂入花生摘果机。项目有望实现花生摘果理论与技术突破，丰富收获机械的技术与理论，为解决我国花生摘果损伤、损失问题奠定理论与技术基础。

花生是世界更是我国重要油料和经济作物。然而，收获过程的摘果环节导致约5%花生果壳开裂、破损和花生米离壳等机械损伤，不仅造成花生果仁损失并降低品质，而且严重危害花生荚果的安全储藏。. 为揭示花生摘果、摘果损伤的发生机理，探索物料学、机构学特性及其摘果过程的运动学和动力学的影响规律，从基础上解决花生摘果损伤问题，项目研究了花生摘果过程的荚果开裂、破损与破碎的损伤形式，花生植株、荚果和果柄的力学特性及其影响因素与变化规律，建立典型的花生果柄断裂静力学模型等；研究了花生植株、荚果、茎秆在摘果过程中的运动学和动力学规律，花生品种、含水率等对摘果及其荚果损伤的影响；试验研究了摘果部件结构参数、速度等对花生摘果的作用力性质和荚果损失规律，建立了相应的数学模型；系统地将花生植株及荚果等生物力学特性、花生摘果动态分析与损伤机理、摘果原理与新型机构等研究成果结合起来，确定了新型花生摘果装置和关键部件结构与各主要参数；研制出花生摘果装置并进行花生摘果的多因素试验研究；通过试验研究，确定了影响摘果机构工作性能的各主要因素及其影响规律，在此基础上进行了摘果装置的优化研究；基于两段和分段式花生收获，研制的新型低损伤花生摘果机具有较强的摘果适应性，摘果损伤率小于3％、秸秆整齐。. 项目研究揭示了花生动态摘果与荚果损伤的机理，探明了其主要影响因素及规律，从而回答了摘果过程中花生荚果损伤如何产生、哪些是主要因素且如何影响、如何从物料学和机构学等实现花生的顺利摘果等科学问题；在此研究基础上，进行了新型花生摘果机构的发明创制、花生摘果试验系统的构建和新型摘果机的研制与试验。项目研究成果对替代和改进新型花生摘果装置的设计、解决花生摘果损伤等问题具有重要理论意义和应用前景，项目研究方法对其他类似机械研究也具有参考价值。