基于趋同进化的凸齿镇压器集成仿生设计及其与南方丘陵山区坡面土壤相互作用机理研究

In hilly sloping farmland of southern China, realize high efficient utilization of water resource is an urgent need for agricultural development. Micro-topographical preparation is the necessary key to achieve this goal. Aiming at the technical difficulty of high soil hardness and frequent adhesion, which impede effective micro-topographical preparation on sloping farmland. This proposed project plan to start from basic theoretical derivation and slope traction test, combined with actual operation conditions and soil conditions of toothed wheel working on hilly slope farmland of southern China, reveal the interaction mechanism between heavy textured soil and toothed wheel on sloping land, then, investigate restriction factors that impede operation quality. Afterwards, based on the idea of convergent evolution in biology, through learning from soil animals, induces the common characteristics of limb structures that have effective digging ability, meanwhile, abstract the similar features body surface morphology that can effectively perform anti-adhesion and drag reduction. Integrated two complementary bionic approach: bionically geometrical structure and bionically geometrical surface, to optimize the design of toothed wheel cutting edge and soil engaging surfaces, respectively. Focus on the research of bionic serrated structures and micro-spiked scale surface, seek the best approach of integration and design parameters. Discover the anti-sticking, drag reduction and anti-friction mechanism of integrated bionically inspired toothed wheel. Eventually, based on convergent evolution establish bionic design method and technique. This proposed project conform to the actual needs, with specific application prospect and has regional characteristics. In addition, this proposed project enrich the research content of agricultural engineering bionics and expand its application territory.

密切结合南方丘陵山区坡耕地农业发展中迫切需要解决的水资源高效利用问题，以及对土壤表面微形貌加工技术的实际需求，围绕凸齿镇压器在坡面粘重土壤作业的技术难点，首先从理论分析和坡面牵引试验入手，针对凸齿镇压器在南方丘陵山区作业的实际工况和土壤条件，揭示凸齿镇压器在坡面与粘重土壤相互作用机理，探明其作业质量的制约因素。其次基于生物学中趋同进化的思想，向土壤动物学习，归纳具有高效土壤挖掘能力的动物肢体结构共有特点、抽象具有优异防粘减阻减摩性能的动物体表形态普遍规律，将仿生几何结构与仿生几何表面两种优势互补的仿生要素相集成，应用于凸齿镇压器的刃口结构和触土表面优化，重点研究仿生锯齿型结构与微刺鳞片型表面，寻求最佳集成参数与方式，探索其防粘、减阻和减摩机理。最后定量评价作业质量，构建基于趋同进化的集成仿生设计方法与技术。本申请项目应用前景明确且具有区域特色，丰富并开拓农业工程仿生的研究内容和应用地域。

南方丘陵山区坡耕地土壤质地粘重，粘结性、粘附性强，导致湿时泥泞，容易与机具发生粘附，导致作业困难；干时坚硬，紧实度高，导致机具作业阻力大、磨损严重。针对上述制约因素，本项目分别选取具有优异防粘能力的克氏原螯虾 (Procambarus clarkii) 和具有优异减阻、耐磨特性的砂鱼蜥 (Scincus scincus) 作为仿生原型开展研究。研究发现，克氏原螯虾头胸部外骨骼中含有大量的钙元素，其中大部分以非晶结构存在，并含有少量碳酸钙；外骨骼表面具有凹坑、凸包和刚毛微观结构；螺旋夹板层具有蜂房结构，钙盐以针簇状分布在螺旋夹板层中；外骨骼硬度为0.503 GPa、弹性模量为18.019 GPa；摩擦因数呈跳跃式变化，最小时不足0.1，最大时接近0.8，磨损类型属于磨粒磨损。砂鱼蜥体表鳞片的形状为扇形或椭圆形，鳞片间紧密排列，形如覆瓦状。此外，体表鳞片分为背部体表鳞片和腹部体表鳞片，两者分布的条纹纹路有深有浅，宽窄不等，条纹纹路上分布有极小的微刺。不同部位的体表鳞片，微刺的高度、间距宽度和数量均不同。.隶属于不同种属的土壤洞穴动物，在进化过程中，为了适应相同或相似的土壤内部环境，发生了趋同进化的现象，前足胫节都出现了功能相同、结构相似的明显特征，即具有高效土壤挖掘能力的锯齿型几何结构。从共性角度出发，综合学习不同土壤洞穴动物挖掘肢体外缘轮廓的几何结构特征，应用于凸齿镇压器刃口的仿生设计。试验结果表明，基于趋同进化思想设计的仿生凸齿作业过程中所需牵引力比普通凸齿可减小6.52%，所加工微坑的深度可增加13.25%，所加工微坑的蓄水容积可增加37.59%。通过有限元方法，探明了具有特定尺寸的仿生凸齿在加工微坑的不同工作阶段，土壤内部产生的应力集中程度均高于普通凸齿，在形成应力集中的土壤局部区域，土壤更容易发生流动和变形，所以在特定载荷下，仿生凸齿加工的微坑容积更大、作业质量更好且作业阻力更小。.研究结果为南方丘陵山区农业机械触土部件表面的仿生防粘、减阻和耐磨提供设计依据；丰富了农业工程仿生的研究方法，并开拓了其应用地域。