摘要
通过引入考虑范德华力和抗转动作用的月壤微观接触模型,采用离散单元法模拟月壤水平推剪试验(简化的土-开挖设备间相互作用模型),对月壤推剪破坏机制进行研究,分析了推剪深度、倾角和速率的影响,为真实月面环境下开挖提供参考。结果表明:推剪过程中推剪阻力首先随推剪位移增加至峰值,而后下降并趋于稳定;随推剪位移的进一步发展,推墙前方土体堆积,推剪阻力缓慢回升,推墙前土体受扰动区范围逐渐增大;当推剪面竖直时,随着推剪深度增加,推剪阻力和能量消耗增大,前方受扰动土体范围增大,破坏面为直平面;相同推剪深度下,推剪倾角越大,推剪阻力和能量消耗越小,前方扰动土体范围越小,破坏面为直平面;推剪速率越大,推剪阻力和能量消耗增大,前方扰动土体范围越大。由于月面开挖时推剪反力由机械与月面摩擦提供,考虑到开挖机械重量受空间运输能力限制,建议采用对推力(机械重量)要求低的浅层、倾斜、慢速开挖,适用于月面早期建设活动。
A discrete element method（DEM） contact model for lunar soil taking rolling resistance and van der Waals forces into consideration is used to simulate the horizontal pushing test, which is a simplified machine-lunar soil interaction problem. The soil failure mechanism and the effects of excavation blade depth, inclination and speed are analyzed; and some suggestions for real lunar excavation are offered. The results show that the pushing resistance increases with pushing displacement to a peak state rapidly and then tends to be stable after a sharp declination. With the accumulation of soil heap in front of the blade, the pushing resistance increases slowly again. The pushing resistance, energy consumption and the affected area are greater under larger pushing depth while the slip surfaces are all straight. As the pushing inclination increases, the pushing resistance, energy consumption and the affected area decrease; and the slip surface remains straight. The pushing resistance, energy consumption and affected area increase with the speed. Since the pushing resistance is provided by frictional force between the machine and lunar ground, which is proportional to the weight of an excavator; it is recommended that shallow, inclined and slow excavation should be used in early-stage lunar base construction. This scheme is advantageous in its low demand for the mass of the excavation machine, thus reducing the mass launched from the earth to the moon.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2016年第1期229-236,共8页
Rock and Soil Mechanics
基金
国家自然科学基金项目(No.51179128)
国家杰出青年科学基金项目(No.51025932)~~
关键词
月壤
离散单元法
水平推剪试验
抗转动作用
范德华力
lunar soil
discrete element method
horizontal pushing test
particle rolling resistance
Van der Waals forces
