磁拟小重力及真空环境模拟月壤力学与工程特性试验研究

Mechanical and engineering properties of lunar soil under lunar-gravity environment is the basis and key for construction and exploitation of mineral resources on the moon. The existing researches, which are mainly based on terramechanics or discrete element method leading to the lack of simulation of low-gravity and vacuum environment, indicates its difficulties to systematically reveal the correlations between mechanical/engineering properties of lunar soil and its influence factors, especially for the effects of low-gravity and vacuum environment. This project aims to improve the existing Geotechnical Magnetic-similitude-gravity Model Testing system, and thus establish the testing platform for lunar soil simulants under low-gravity and vacuum environment. The research will focus on the mechanical properties of lunar soil, with consideration of the geometric characteristics, including particle size distribution and particle shape, and develop the new-type lunar soil simulants for experimental tests. The deformation, strength, and engineering properties of lunar soil simulants, including the coupling effects of particle geometry, low gravity and vacuum environment, will be thoroughly investigated, through triaxial compression/tension tests, direct shear tests, confined compression tests, static loading tests and miniature cone penetration tests. By comparisons with the existing research, the current project will reveal the mechanical properties of lunar soil simulants, especially for the formation and evolution of weak cohesion and small tensile strength. This research will significantly contribute to the Chinese Lunar Exploration Program and its further space exploitation.

月球环境下月壤力学与工程特性是月球基地建设与矿产资源开发的基础与关键。现有研究主要基于地面力学，或采用离散元等方法，缺少对小重力、真空环境的真实模拟，难以系统、可靠、准确揭示月壤力学、工程特性与诸影响因素之间的关系，特别是小重力、真空等特殊环境效应。本课题拟在完善既有磁拟重力模型试验系统基础上，构建模拟月壤试验的小重力、真空物理环境与试验平台；以颗粒级配、颗粒形状等月壤几何特征为重点，聚焦月壤力学特性，研制适用于试验系统的新型模拟月壤；通过三轴压缩试验、拉伸试验、直接剪切试验、侧限压缩试验以及静荷载、静力触探小模型试验，研究获得模拟月壤的变形、强度性质和工程特性，以及颗粒几何特征、小重力、真空等耦合环境效应，并与国内外研究成果对比分析，揭示模拟月壤的力学特性，特别是弱内聚力、小抗拉强度的形成机理与演化机制。研究对于“中国探月工程”及其太空开发战略的实施具有重要意义。

随着我国探月工期持续推进，系统获得月表极端环境下月壤力学与工程特性已成亟需。本项目针对当前月壤力学研究中缺乏对月表环境模拟及其与月壤力学特性耦合机理揭示的现状，系统开展了小重力、真空环境下月壤力学与工程特性研究，揭示了月壤行为的特殊环境效应。项目攻克了强磁场环境真空营造关键技术，研制了月表小重力、真空环境模拟试验系统，实现了月表极端环境的模拟；聚焦颗粒级配、形状等月壤几何特征，攻克了“高温熔融”和“动力破碎”关键技术，研制了CUMT-1模拟月壤，实现了月壤物理力学特性的模拟；系统提出了月壤颗粒形态表征方法，实现了对月壤颗粒整体、局部及纹理特征等异形形貌的定量表征与数字重构；开展了模拟月壤三轴剪切试验、拉伸试验、侧限压缩试验以及静荷载、静力触探小模型试验，获得了月表环境下月壤介质变形、强度性质和工程特性，揭示了其颗粒几何特征与小重力、真空等环境的耦合效应及演化机制。项目研究成果将为我国探月工程四期月球科研站建设、资源原位利用等月面活动提供重要的理论基础。