Equivalent verification method for extreme hypothermic environment adaptability of lunar polar drill bit cutting tools

Aiming at the problems of high cost and great difficulty in verifying the performance of the drill bit cutting tools in the extreme hypothermic environment (20-40 K) of the lunar polar regions, this paper proposes an equivalent verification method based on the liquid nitrogen temperature range (-180?C). Through a systematic analysis of the influence mechanism of extremely low temperature on the mechanical properties of lunar regolith and the performance of drill bit materials, the stable threshold of the strength of the frozen soil working condition changing with temperature is determined, and the key risk of the increase in internal stress caused by the thermo-mechanical coupling deformation of the drill bit is revealed. Based on the equivalent principle of material impact work and the compensation strategy for thermal stress increment, an equivalent verification theoretical framework with the core of kinetic energy proportional scaling and external load superposition is constructed, and a multi-dimensional test matrix covering the working conditions of dry soil and frozen soil is designed. The research results show that, by optimizing the driving parameters of the drilling tool and the load conditions, this method can effectively simulate the mechanical impact and structural stress effects of the extreme hypothermic environment on the cutting tools, providing an innovative solution for the low cost and high efficiency verification of the reliability of drilling tools.