大颗粒岩块对月壤钻取过程的影响分析

发布时间：2018-11-13 13:21

【摘要】：针对月壤钻取采样过程中存在大颗粒岩块情况进行三维离散元动态仿真分析。建立考虑扭转、弯曲力矩及等效引力作用的新型三维离散元月壤模型,通过三轴仿真试验进行细观参数标定,得到黏聚力为0.90 k Pa,内摩擦角为42.25°的满足真实月壤宏观力学指标的仿真模型。针对月壤内层存在大颗粒情况设计4种采样工况分别进行仿真分析,监测大颗粒运动轨迹与采样效率,发现了"旋入效应"、"纵向运移效应"与"阻塞效应",仿真结果表明岩块粒径大小直接影响采样结果:当岩块粒径小于钻头"虚拟切削圆"时,其无论存在于任何位置对采样效率与后续样品缠绕收集均无明显影响;当岩块粒径大于"虚拟切削圆"时,阻塞现象严重,样品收集困难,极易导致采样失败。研究结论对月壤钻取采样控制设计与钻具结构设计具有重要的工程参考价值。
[Abstract]:Three dimensional discrete element dynamic simulation analysis is carried out in view of the existence of large granular rock masses in the sampling process of lunar soil drilling. A new three dimensional discrete element lunar soil model considering torsion, bending moment and equivalent gravity was established. The mesoscopic parameters were calibrated by triaxial simulation test. The cohesion force of 0.90k Pa, was obtained. A simulation model with an internal friction angle of 42.25 掳satisfies the macro mechanical index of real lunar soil. According to the large particles in the inner layer of lunar soil, four sampling conditions were designed and simulated respectively to monitor the movement track and sampling efficiency of large particles, and the "swirling effect", "longitudinal migration effect" and "blocking effect" were found. The simulation results show that the size of rock block has a direct influence on the sampling results: when the size of rock block is smaller than the "virtual cutting circle" of the bit, the sampling efficiency and subsequent sample winding collection are not significantly affected by its presence in any position. When the size of rock block is larger than "virtual cutting circle", the blocking phenomenon is serious and the sample collection is difficult, which can easily lead to sampling failure. The research results have important engineering reference value for the sampling control design of lunar soil drilling and the structure design of drilling tools.
【作者单位】：哈尔滨工业大学航天工程系;
【基金】：国家自然科学基金项目(51105100) 教育部博士点基金项目(20112302120007) 中国博士后科学基金项目(20110491050) 国家重点实验室开放基金项目(HIT.KLOF.2011.075)
【分类号】：P184.5

【参考文献】