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Study on the Lunar Soil Simulant by Model Tests of Water Seepage

Author: TianXingJian
Tutor: ChenLun
School: Tsinghua University
Course: Civil Engineering
Keywords: lunar soil stimulant model tests of water seepage gravity field
CLC: P184
Type: Master's thesis
Year: 2010
Downloads: 43
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Abstract

China’s lunar probe program is very important to the exploration of space resources and strengthening the national capabilities. It is necessary for us to be aware of situation of the interaction of lunar soil and manual facilities to realize the moving of moon rover, inspection tests on soil sampling and constructions of a lunar base. Physical and mechanical properties of lunar soil have an impact on these problems. When interaction problems are studied, the different gravity effect on the engineering properties of lunar soil simulant should be paid attention to.Volcanic ash in Jingyu, Jilin province is selected as primary material in this paper, as it can simulate the actual lunar soil physical and mechanical properties of the main. Triaxial tests of dry and saturated lunar soil simulant are carried out to obtain the physical and mechanical parameters.The test equipment of water seepage model used in this paper is made of test chamber, measuring and recording device, test bed and so on. Through seepage model tests, the interactions are studied of lunar soil and simplified artificial device on the detectors, such as the load board system, tube simulant system and the pull plate system. The tests of 1/6g, 1g, 2g and 6g gravity field show that: gravity field has great impact on manual facilities of the same size. With the increasing of simulated gravitational field, the pressures and forces on the load plate, tube and steel plate of the same displacement increase, but the increasing rates are different from those of gravitational field. Boundary effect has a certain influence on the model, in the tube simulant test for example, with the same simulated gravity field and tube size, the force of the center tube is slightly larger than that of the tube 10 cm away from the center. In tube test, when gravity field is 2g and 6g, the shear stress of small tube reaches its peak rapidly and becomes stable, while the shear stress of medium and large tubes develops slowly in the beginning until a certain depth of penetration to increase and keeps increasing. In 1/6g gravity field, the shear strength of the three tubes increases from the beginning until the peak. When the gravity field is 1g, in the initial stage, the shear stress of small and medium tubes quickly covers the starting strength and falls to a stable value, while that of large tube develops slowly until a certain depth of penetration. There is a significantly linear relation between the maximum net forces when pulling plate is pulled out and the corresponding gravities. But there is a considerable gap between the maximum net forces and the theoretical values.Conclusions in this paper can be of reference value for the study of the interaction of lunar rovers, prospecting equipment and lunar soil simulant as well as constructions of a lunar base.

Study on the Lunar Soil Simulant by Model Tests of Water Seepage

Abstract

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