面向根土复合体的高效切割结构仿生设计方法研究

In order to solve the problem that the existing tillage tools of agricultural machinery can not realize efficient cutting for the root-soil complex and they are difficult to meet the development needs of modern agricultural planting patterns. The present project explores the strengthening and toughening mechanism of root-soil complex by analyzing its composition, structure, mechanical properties and destructive behavior, and then creates the performance evaluation method oriented to the cutting component of root-soil complex in combination with the requirements of different soil, crops and operations; By analyzing the characteristics of excavating organ components, multi-scale structures and movement mode of different talpidae animal, we explore the common coupling mechanism of high-efficient cutting, adhesion-reducing and anti-winding of the root-soil complex in the process of excavation, and carry out the bionic design, evaluation and optimization of common efficient cutting structure, multi scale anti visbreaking winding structure and movement mode of ditching and weeding for the root-soil complex; In addition, we also analyze the differentiated characteristics and evolution mechanism of different talpidae animal for environmental characteristics, excavated organs and their movement mode, and then explore the differential design and evaluation of the cutting structure for different root-soil complex on the basis of excavating organ and movement mode of talpidae animal in the corresponding environment; Finally, a sustainable and differentiated design method of efficient cutting structure for root-soil complex is constructed by establishing experimental data base and analyzing the functional law of differentiated design for the part optimization under certain conditions.

本项目将针对现有农机耕作部件无法对根土复合体实现高效切割，难以满足现代农业种植方式发展需求的问题，通过分析根土复合体的组成、结构、机械性能和破坏行为，探索其强韧化机理，并结合不同的土壤、作物、作业环节等要求，创建面向根土复合体切割部件的性能评价方法；通过分析不同鼹科动物挖掘器官成分、多尺度结构和运动方式特征，探索其在挖掘过程中对根土复合体高效切割、减粘和防缠绕的共性耦合作用机理，并开展面向根土复合体的开沟和除草部件共性高效切割结构、多尺度减粘防缠结构和运动方式的仿生设计、评价与优化；分析不同鼹科动物针对环境特征，挖掘器官及其运动方式的差异化特征及进化机制，并针对不同根土复合体，以相应环境中鼹科动物挖掘器官及其运动方式特性为基础，进行切割结构的差异化设计与评价；通过建立试验数据库，并分析差异化设计对部件针对特定条件优化的作用规律，构建形成面向根土复合体高效切割结构的可持续差异化设计方法。

本项目面向农田中典型的根土复合体，针对耕作部件在切割根土复合体时面临的切割阻力大、磨损严重、粘附大以及深层土壤与浅层土壤干湿混合等农艺问题，开展了仿生切割部件的设计理论和方法研究。通过对裸鼹鼠、蟋蟀、鼢鼠、切叶蚁等仿生对象的研究，有针对性地对仿生对象的微观结构，几何结构以及力学性能的研究与分析，利用万能试验机测量了其力学特性，利用钨灯丝扫描电子显微镜探究其微观结构，探究出微观结构与硬度差异之间的关系。基于计算机断层扫描技术、三维重构以及图像识别的方法，构建出裸鼹鼠门齿结构、切叶蚁蟋蟀的大颚结构、鼢鼠前爪爪趾结构等关键器官结构切割部位的数字化模型，并探究其关键结构参数对切割根土复合体造成的影响，设计出了，开沟器、被动式破茬刀、主动式破茬刀、除草铲等切割耕作部件，并寻找到高效切割结构的设计方法与关键设计参数。通过对玉米根土复合体、杂草根土复合体的结构力学特性的研究，构建出其离散元模型与有限元模型，利用模拟分析与优化方法，寻找到最佳的设计结构，并探究了不同切割部件的高效切割机理。通过加工，将设计好的耕作部件加工出来，并在大田中进行试验，并达到了预期效果。为了提高切割部件的减黏耐磨性能，对耕作部件的表面结构进行了设计，采用了贝壳表面的棱纹结构，并利用离散元法与优化方法探究其最佳设计参数。通过对陶瓷涂层的摩擦磨损性能的研究，探究出了陶瓷涂层增强材料耐磨性能的机理，通过磨损试验，探索了其磨损性能与机理。耐磨涂层能够有效降低试样的磨损率和摩擦因数。