Dynamic analysis of research on statistical and morphological parameters of lunar regolith particles

Abstract

[Objective] The physical and mechanical properties of lunar regolith are clarified to support deep-space exploration and the construction of scientific research stations, and to further reveal the relationship between particle parameters of lunar regolith and its occurrence environment to guide the preparation of lunar regolith simulants. [Methods]The environmental information of lunar regolith sampling sites since 1969 was systematically reviewed. The published indicators of lunar regolith, including mineral composition, particle gradation, bulk density, and fractal dimension were summarized. The raw materials and preparation method of typical lunar regolith simulants were analyzed, and research progress on the characteristics of lunar regolith under simulated lunar environments was examined. On this basis, research recommendations and development prospects for preparation method of lunar regolith simulants were proposed from the perspective of soil mechanics. [Results] The result showed that the Si O₂ content in lunar regolith accounted for approximately 45%, and the dry bulk density ranged from 0. 89 to 1. 6 g·cm^-3. The particle gradation was dominated by fine particles, with significant differences among different sampling regions. Among morphological parameters, the fractal dimension ranged from 2. 28 to 2. 55, and the specific surface area ranged from 0. 40 to 0. 56 m²·g^-1. The single-material grinding and sieving method for lunar regolith simulants was suitable for largescale tests. A similarity of more than 85% was achieved by the multi-mineral precise compounding method, and a compressive strength of 3. 2 ~ 21. 52 MPa was obtained via the functional modification preparation method. Experimental studies on lunar regolith simulants focused on three major themes: mechanical property tests, biological planting tests, and physical effect tests. [Conclusion] The dominant minerals of lunar regolith are plagioclase, pyroxene, olivine, and ilmenite, exhibiting “low-alkali and high-iron” characteristics, with significant differences in mineral composition between mare and highland samples. The current preparation of lunar regolith simulants can adopt corresponding method according to different objective, and the effective similarity evaluation of lunar regolith simulants can be conducted from three dimensions: mineral composition, physical properties, and mechanical properties. The findings can provide references for the preparation of lunar regolith simulants and the study of physical and mechanical properties of lunar regolith.

Keywords

geotechnical engineering / lunar regolith parameters / lunar regolith simulant / similarity / lunar regolith simulant testing / influencing factors / soil mechanics / fractal dimension