Simulation of Icy Lunar Regolith and Experiment on Its Shear Strength

Abstract

In order to obtain the shear strength of Icy Lunar Regolith (ILR) in the Permanently Shadowed Region (PSR) of the Moon, the physical properties of ILR such as mineral composition, particle size distribution, dry density, water content and deposition temperature were analyzed, and a method for ILR simulant preparing and parameters testing was proposed. Based on the Variable-Angle Shear Test (VAST) method, shear strength tests of ILR simulant were conducted with a mixed raw material made of anorthosite and basalt, dry density of 1.71g/cm³ (i.e. 100% relative density), water content from 3.7 wt% to 9.5 wt%, and temperature below –180°C. The result shows that the shear damage mode of the ILR simulant under low confining pressure is dominated by brittle fracture on the shear surface, but with the increase of the confining pressure, the brittleness of the ILR decreases and the ductility increases. In this case, its damage mode changes to compression-shear damage, and the shear strength decreases. The shear strength parameters of the ILR simulant under low confining pressure were calculated according to the linear Mohr-Coulomb criterion. The results show that the cohesion increases linearly with the increase of water content, but the internal friction angle hardly varies with water content, with values between 50° and 53°.

Keywords

Icy Lunar Regolith (ILR) / Lunar Regolith Simulant (LRS) / Variable-Angle Shear Test (VAST) / shear strength / Mohr-Coulomb theory

References

[1] 吴伟仁,于登云,王赤,等. 月球极区探测的主要科学与技术问题研究[J]. 深空探测学报(中英文),2020,7(3):223-231
WU W R,YU D Y,WANG C,et al. Research on the main scientific and technological issues on lunar polar exploration[J]. Journal of Deep Space Exploration,2020,7(3):223-231
[2] 何成旦,李亚胜,温智,等. 月表水冰探测与赋存形态研究进展[J]. 真空与低温,2021,27(6):589-600
HE C D,LI Y S,WEN Z,et al. Research progress of lunar surface waterice detection and occurrence form[J]. Vacuum and Cryogenics,2021,27(6):589-600
[3] WILLIAMS J P,GREENHAGEN B T,PAIGE D A,et al. Seasonal polar temperatures on the Moon[J]. Journal of Geophysical Research:Planets,2019,124(10):2505-2521
[4] GERTSCH L S，ROSTAMI J，GUSTAFSON R. Review of lunar regolith properties for design of low power lunar excavators[C]//Proceedings of the 6th International Conference on Case Histories in Geotechnical Engineering. Arlington，VA：[s. n. ]：2008.
[5] ATKINSON J，ZACNY K. Mechanical properties of icy lunar regolith：Application to ISRU on the moon and mars[C]//Proceedings of Earth and Space 2018：Engineering for Extreme Environments. Reston，VA：[s. n.]：2018.
[6] PITCHER C,KÖMLE N,LEIBNIZ O,et al. Investigation of the properties of icy lunar polar regolith simulants[J]. Advances in Space Research,2016,57(5):1197-1208
[7] LIU J,ZHANG W,TIAN Y,et al. Analysis and prediction of uniaxial compressive strength of icy lunar regolith under extreme temperature[J]. Advances in Space Research,2022,69(12):4391-4407
[8] 李龙,周琴,张凯,等. 冻土机械切削破碎机理的研究进展[J]. 冰川冻土,2021,43(2):638-649
LI L,ZHOU Q,ZHANG K,et al. Research progress on mechanical cutting fracture mechanism of frozen soil[J]. Journal of Glaciology and Geocryology,2021,43(2):638-649
[9] 郑国敬,周琴,张凯,等. 单齿回转切削力学模型的研究进展[J]. 煤炭学报,2018,43(S2):573-580
ZHENG G J,ZHOU Q,ZHANG K,et al. Advances and trends in the study on rotary cutting mechanical model of single cutter[J]. Journal of China Coal Society,2018,43(S2):573-580
[10] 刘君巍,汪恩良,田野,等. 月壤水冰组构模拟及力学特性测试分析[J]. 深空探测学报(中英文),2022,9(2):134-140
LIU J,WANG E,TIAN Y,et al. Fabric simulation and mechanical characteristics test and analysis of icy lunar regolith[J]. Journal of Deep Space Exploration,2022,9(2):134-140
[11] BASU A,RIEGSECKER S. Modal mineralogic distribution in the regolith at Apollo landing sites[J]. Journal of Geophysical Research:Planets,2000,105(E2):4361-4368
[12] SUN X,ZHANG R,LI X,et al. JLU-H:a novel lunar highland regolith simulant for use in large-scale engineering experiments[J]. Planetary and Space Science,2022,221:105562
[13] 李建桥,邹猛,贾阳,等. 用于月面车辆力学试验的模拟月壤研究[J]. 岩土力学,2008,29(6):1557-1561
LI J Q,ZOU M,JIA Y,et al. Lunar soil simulant for vehicle-terramechanics research in labtory[J]. Rock and Soil Mechanics,2008,29(6):1557-1561
[14] HE X，XIAO L，HUANG J，et al. Lunar regolith simulant CUG-1A[C]//Proceedings of the 41st Annual Lunar and Planetary Science Conference. The Woodlands，Texas：[s. n]：2010.
[15] ZENG X,HE C,WILKINSON A. Geotechnical properties of NT-LHT-2M lunar highland simulant[J]. Journal of Aerospace Engineering,2010,23(4):213-218
[16] BUTLER J C，GREENE G M，KING JR E A. Grain size frequency distributions and modal analyses of Apollo 16 fines[C]//Porceedings of the Fourth Lunar Science Conference （LSC 1973）. Houston，Texas：1973.
[17] HEIKEN G H，VANIMAN D T，FRENCH B M. Lunar Sourcebook：a user’s guide to the Moon[M]. Cambrideg：Cambridge University Press. 1991.
[18] 季节,张伟伟,杨旭,等. 月球极区水冰采样探测技术综述[J]. 深空探测学报(中英文),2022,9(2):101-113
JI J,ZHANG W W,YANG X,et al. Overview of water ice sampling and detection techniques in the lunar polar region[J]. Journal of Deep Space Exploration,2022,9(2):101-113
[19] COLAPRETE A,SCHULTZ P,HELDMANN J,et al. Detection of water in the LCROSS ejecta plume[J]. Science,2010,330(6003):463-468
[20] ANDREAS E L. New estimates for the sublimation rate for ice on the Moon[J]. Icarus,2007,186(1):24-30
[21] PAIGE D A,SIEGLER M A,ZHANG J A,et al. Diviner lunar radiometer observations of cold traps in the Moon’s south polar region[J]. Science,2010,330(6003):479-482
[22] DU K,LI X,WANG S,et al. Compression-shear failure properties and acoustic emission (AE) characteristics of rocks in variable angle shear and direct shear tests[J]. Measurement,2021,183:109814
[23] ASUERO A G,SAYAGO A,GONZÁLEZ A G. The correlation coefficient:an overview[J]. Critical Reviews in Analytical Chemistry,2006,36(1):41-59
[24] 朱志武,宁建国,马巍. 冻土屈服面与屈服准则的研究[J]. 固体力学学报,2006(3):307-310
ZHU Z W,NING J G,MA W. Study on yield surface and yield criterion of frozen soil[J]. Acta Mechanica Solida Sinica,2006(3):307-310
[25] 周兆曦，马芹永. 负温下模拟月壤三轴压缩试验与分析[J]. 合肥学院学报（综合版），2022，39（2）：26-31.
ZHOU Z X，MA Q Y. Triaxial compression test and analysis of simulated lunar soil at negative temperature[J]. Journal of Hefei University （Comprehensive Edition）. 2022，39（2）：26-31.
[26] WANG Y,FENG W K,LI C H,et al. An investigation into the effects of block size on the mechanical behaviors of bimsoils using variable-angle shear experiments[J]. Environmental Earth Sciences,2020,79(3):1-13