基于深海底质土细观粘附特性分析的仿生履齿自清洁机理研究

With land mineral resources gradually exhausted, our country has turned to ocean with rich mineral resources, and currently focused on pipeline hydraulic transportation system to meet the future commercial exploitation. In pilot phase of the mining system, grouser of the mining machine has a serious sticky sediment problem, which leads to mining machine sliding and mining efficiency decreasing due to the decline in effective shear height of the grouser, even threatens the safe operation of the whole mining system. Aiming at adhesion characteristics of deep-sea sediment, the discrete element theory and the soil adhesion theory are used to establish accurate mesoscopic-adhesion mechanics model for the deep-sea sediment collected from the Pacific C-C mining area. Using the discrete element platform, mesoscopic-adhesion mechanics program of deep-sea sediment is developed to investigate self-cleaning mechanism of the bionic grouser for obtaining the mathematical description and control parameters of the self-cleaning bionic grouser. Finally, based on the walking characteristics test apparatus for bionic grouser assembled by ourselves, the self-cleaning property of the bionic grouser are studied for the future application in deep-sea mining technology.

随着陆地资源的日益枯竭，我国将目光转向了富含矿产资源的海洋，并正在研制集矿机与管道提升相结合的采矿系统以适应今后商业化开采需要。该采矿系统在中试阶段发现集矿机履齿有严重的粘泥问题，导致履齿的有效剪切高度下降而打滑，影响了集矿机采矿效率，甚至威胁到整个采矿系统的安全运行。本研究基于离散元理论和土壤粘附理论，结合采自太平洋C-C矿区的深海底质土，针对其粘附特性，建立精确的细观粘附力学模型。利用离散元平台，开发深海底质土细观粘附力学计算程序，结合深海集矿机的行走特性，开展集矿机履齿仿生自清洁机理研究，并在此基础上获得仿生自清洁履齿齿形的数学描述和控制参数。最后，基于自行装配的仿生履齿行走特性试验台，研究仿生履齿脱土自清洁特性，以验证其自清洁效果，为其应用于我国深海开采技术提供重要依据。

针对我国深海采矿系统在中试阶段出现的集矿机履齿严重粘泥问题，本课题基于液态环境原子力显微镜（原位AFM）分析深海土颗粒与四种金属之间的粘附特性，获得最优自清洁性能的金属，同时建立粘附力与表面粗糙度的关系。首次引入表层土粘附指数ηs描述深海底质土与金属界面间粘附特性，建立粘附指数与孔隙比、法向压力、加载速度的计算公式。采用离散元法（DEM）计算不同仿生履齿的行走过程，获得仿生履齿脱粘机理，并通过最优化算法获得了仿生履齿脱粘效果最佳的齿形参数，并通过试验进行验证。基于深海底质土的流变特性，采用率相关扩展Drucker-Prager本构模型和分数阶Burgers流变本构模型，分别获得仿生增力履齿最佳齿形参数、履带最佳接地长度和最佳行走速度，所得成果可作为国家重大工程“蛟龙探海”重要理论基础。本课题组于2018年参与我国首次海底多金属结核集矿系统500米海试，为我国商业化开采多金属结核矿产资源提供重要技术支持。