正反换向滚筒刮拉式香蕉茎秆纤维提取机理及其仿生优化设计研究

Banana stalk is rich in plant fiber, currently, the mechanical extraction of banana stalk fiber still remains lower working efficiency, lower extraction rate, higher power consumption, easier to plug and so on. To solve the problem above, this project through the study of the mechanical and physical properties of banana stalk fibers, which clearing the stress distribution of banana stalk fibers and then constructing the mechanical model of banana stem fiber; Based on the mechanism of the banana stalk fiber extraction of active feeding obverse-reverse-type to study the"Dehydration - Broken - Impurity - Separation" mechanism, applying the mechanical dynamics and kinematics theory to construct the random motion model of variables (such as displacement, velocity, load and so on) of extracting banana stalk fiber, which to reveal the coupling mechanism of dynamic characteristics and mechanism motion during the fiber extraction; Based on bionics to study the anti-adhesion and drag reduction mechanism of mechanical bionics, which to explore the method of bionic design of banana stalk fiber extraction; Introducing the multi-objective optimization method to study the prototype, in order to explore the mathematical modeling and algorithm for optimization design, which to improve the extraction rate of the machine, reduce power consumption and weight. The successful implementation of the project will lay a solid theoretical for high-performance Banana stalk fiber extraction machine, which has an important practical significance for promoting the sustainable development of agriculture in tropical agricultural areas.

香蕉茎秆中含有丰富的植物纤维，目前，机械提取香蕉茎秆纤维存在工作效率低、提取率低、功率消耗大和易堵塞等问题。为解决上述问题，本项目通过研究香蕉茎秆纤维的物理机械特性，明确香蕉茎秆纤维的应力分布规律，构建香蕉茎秆纤维的力学模型；基于正反换向滚筒刮拉式香蕉茎秆纤维提取机构，研究香蕉茎秆纤维提取 “挤压-破碎-刮拉-分离”过程，应用机械动力学和运动学理论，构建香蕉茎秆纤维提取过程中位移、速度、载荷等变量的随机运动模型，揭示纤维提取动态特征与机构运动的耦合机理；基于仿生学，研究机械仿生减粘降阻机理，探索纤维提取关键机构的仿生设计方法；引入多目标优化方法对样机进行研究，探索优化设计的数学建模方法和求解算法，提高机器提取率、减少功率消耗并实现轻量化。本项目的成功实施，将为高性能香蕉茎秆纤维提取机的设计奠定坚实的理论，对促进我国热带农业区农业可持续发展具有重要的现实意义。

针对香蕉茎秆纤维强度低，刮拉容易断茎、提取容易堵塞以及香蕉茎秆纤维提取率低、含杂率高等难题，本项目创新设计多项香蕉茎秆纤维提取技术。通过对香蕉茎秆纤维的显微结构、机械物理特性进行研究，明确香蕉茎秆纤维的应力与应变间的相互关系，进而分析香蕉茎秆纤维的破裂形式；基于生物仿生的非光滑表面具备的脱附减粘特性，以土壤动物蜣螂的前甲壁表面结构为本次设计的仿生对象，结合模块化理念，对香蕉茎秆纤维提取机的滚轧装置及纤维整平输出装置进行仿生设计，并通过力学分析探索研究非光滑表面粘附性能和摩擦性能的主要影响因素；基于Design-Expert软件，设计正交试验并构建以杂质粘附率为指标的回归方程，分析各影响因素对试验指标的作用关系；以香蕉茎秆纤维提取率、香蕉茎秆纤维含杂率为试验指标，纤维提取装置刮杂刀辊转速、刮刀数量、刮刀砧弧长为影响因素，通过单因素试验分析确定了各个因素对试验指标的影响规律及较优水平范围；通过三因素三水平正交试验及多元回归分析，得出刮杂刀辊转速为1 850 r/min、刮刀数量为16 把、刮刀砧弧长为65 mm为试验最优参数组合，以及各因素对指标影响的主次顺序。优化设计的纤维提取机生产率为207.6 kg/h，香蕉茎秆纤维提取率为93.2%，香蕉茎秆纤维含杂率为15.7%，能耗为22.1 kW﹒h/100kg。开展仿生型纤维提取机和非仿生型纤维提取机的对比试验研究，明确仿生型纤维机的主要工作性能。通过引入多目标优化方法对样机进行研究，探索优化设计的数学建模方法和求解算法，提高机器纤维提取率、减少功率消耗并实现轻量化。项目实施期间，研制试验样机3台，发表学术论文11篇，其中SCI/EI期刊论文8篇；授权国家专利11项，其中发明专利授权4项，实用新型授权7项；建立香蕉秸秆机械化处理研究创新团队，培养中青年骨干教师3名，培养硕士研究生4名。