Experimental study of tensile mechanical behavior of lunar rock simulant under real-time lunar-based in-situ temperature

Abstract

In-situ condition-preserved coring of lunar rock samples is crucial for lunar resource exploration and research station construction. A reliable understanding of the basic physical and mechanical properties of lunar rocks under the Moon’s extreme temperature conditions is a prerequisite for these efforts. Brazilian tests were conducted on lunar rock simulant under simulated lunar temperatures (−120 to 200 °C) to investigate the relationship between tensile strength and in-situ temperature. The results indicate that tensile strength, peak tensile strain, and the duration to peak load all decrease nonlinearly with increasing temperature. Micro-morphological observations show that the tensile fracture surfaces are complex, with high-temperature specimens exhibiting rougher surfaces and more pronounced fracture cracks than low-temperature specimens. The fracture morphology is dominated by intergranular cracking, together with small-scale cleavage rivers, cleavage steps, and a small plane of analogous cleavage, as further supported by box fractal dimension analysis of the fracture surfaces. Additionally, matrix tensile failure is identified as the dominant failure mode in Brazilian tests under simulated lunar temperature conditions. These findings provide a scientific basis and theoretical reference for in-situ condition-preserved deep coring of lunar rocks in the Moon’s extreme thermal environment.

Keywords

lunar rock simulant / real-time in-situ temperature / tensile strength / mechanical properties / fractal dimension

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