月壤双轴试验的剪切带离散元数值分析  

Distinct element analysis of shear band of lunar soil in biaxial tests

作　　者：蒋明镜[1,2] 郑敏 王闯[4] 

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092 [3]云南省交通规划设计研究院,昆明650011 [4]中国空间技术研究院,北京100094

出　　处：《岩土力学》2012年第12期3801-3809,共9页Rock and Soil Mechanics

基　　金：国家杰出青年科学基金项目(No.51025932);国家自然科学基金项目(No.10972158;No.51179128);上海市优秀学术带头人计划项目(No.11XD1405200)

摘　　要：土体的破坏问题一般都是从其剪切带入手进行研究的。针对真实月壤所处的环境(无水、低重力场、低气压等)和内摩擦角较大的特点,采用最近提出的1种考虑粒间抗转动作用与粒间范德华力2个因素的月壤散粒体力学接触模型,用离散单元法模拟了柔性边界条件下月球环境(含范德华力)与地球环境(不含范德华力)2种试样的双轴压缩试验,通过试样局部变形、速度场、孔隙比及转动场的变化情况研究了2种试样剪切带形成与发展。研究结果表明,剪切带的形成是试样内部应变局部化的结果,同时也伴随着试样内部颗粒相对转动的局部化,月面环境对试样的破坏形式与性状(剪切带的倾角及厚度)有显著的影响,探月工程中必须考虑到月面环境对月壤力学性质的影响。The problem of failure of soil is generally studied by shear band. The lunar environment is quite different from the earth such as Anhydrous, low gravitational fields, and very low atmospheric pressure etc.; and the internal friction angle of lunar soil is quite large. In this paper, particle rolling resistance and Van der Waals forces between lunar soil particles are taken into consideration in the new lunar soil contact model. With this model several flexible boundary biaxial compression tests are simulated by distinct element method （DEM）. The results show that the formation of shear band is characterized with both strain localization and the pure rotation ratio （APR） localization; and the lunar environment has a significant influence on failure modes of samples, such as inclination and thickness of the shear band. The influence of lunar surface environment on the mechanical properties of lunar soil should be taken into account in lunar exploration.

关 键 词：月壤 离散单元法 范德华力 抗转动 双轴试验 剪切带 

分 类 号：TU431[建筑科学—岩土工程]