Distinct element method study of the static and flow mobility characteristics of lunar regolith based on the particle shape characteristic

Due to the uniquely physical and mechanical characteristics of lunar regolith, studying the differences in static and flow mobility properties between lunar and other materials, is extremely important for In Situ Resource Utilization, base station location selection, and construction in lunar exploration. Based on the data of lunar regolith of shape characteristics, this article employed the distinct element method (DEM) to study the static and flow mobility characteristics of lunar regolith. Firstly, to reproduce the macroscopical static and flow behaviors on the sample of lunar regolith, a complete three-dimensional contact model which considered the grain shape characteristics of Chang’E-5 mission is used, then the corresponding shape parameters (coefficient of rolling resistance β) with different grain sizes are determined. Secondly, the triaxial test under different confining pressure and the rotating drum test under different rotating speeds are simulated using DEM, which samples include the lunar regolith, toyoura sand, and glass bead. Finally, a contrastive analysis of static and flow mobility characteristics of the three materials is performed. The simulation results show that, in the triaxial tests, compared with the other two materials, the lunar regolith has the largest cohesion and internal friction angle, and it has the dilatancy in the shearing process. In the rotating drum tests, compared with the other two materials, lunar regolith has the largest inclination angle and void ratio, and the smallest shearing rate and coordination number. Under a certain range of inertia number, the lunar regolith has the largest effective friction coefficient compared with the other two materials, which correspond it has the smallest flow mobility.