Geotechnical Engineering Properties of Lunar Soil Simulants
ABSTRACT The goals of lunar soil mechanics studies are both to improve scientific knowledge about the properties of lunar soil and to provide the engineering knowledge needed to plan and perform lunar surface activities. To enhance the scientific understanding of the behavior, and the mechanisms responsible for shear failure of lunar soil, geotechnical properties of different simulants have been evaluated. Mechanical and engineering properties of a simulant UNB-AN-1 were determined experimentally. Conventional triaxial compression experiments were conducted on UNB-AN-1 at a density of 1.7 g/cc which is close to the average density of the upper few centimeters of the lunar surface. The shear strength dependence on grain size distribution of simulants has been analyzed experimentally. The small amount of difference in grain size distribution results in different shear strength properties for the simulants. The effect of particle shape on the behavior of lunar soil was simulated with an illustrative microstructure deformation mechanism for angular materials as lunar soil. The effect of particle size and particle shape is more dominant at low confinement. Thus, more consideration is needed for the microstructural properties of lunar soil.