A share-point is a cutting edge of the ploughshare, the crucial component of a horizontally reversible plough (HRP). Our previous trials in sandy loam soil indicated that severe abrasion/attrition wear with white materials appeared at the share-point in the high-speed shifting tillage operation of the HRP. This mechanical fatigue was demonstrated to be caused by the flowing soil-tool interaction. But whether the white materials are associated with the thermal effects due to the high-speed tillage is not known. This paper extended our previous work to evaluate the thermal effects by using a combined multi-body dynamics analysis (MDA) and fluid-solid-thermal simulation. The dynamic interaction between soil and share-point was studied with the MDA approach. Based on the generated tillage forces through the MDA, a fluid-solid-thermal model of the ploughshare was developed to investigate the specific quantitative results, maximum stresses and temperatures observed at the share-point, which were further compared with the published worn-lands at the same tillage conditions (such as tillage speed and depth). The comparisons showed that the maximum coupled stresses and tillage temperatures in this study both appeared at the share-point, particularly at the most severe abrasion/attrition with white materials, and that they were both varied with the different working conditions or the different tillage behaviours. Our findings demonstrate that the high-speed shifting operation of HRP has the thermal effects on the share-point wear due to the fact that the greatly varied tillage temperatures can accelerate to impact the surface integrity because of the thermal stresses detrimental to the micro-shape or size shape at the share-point section. This result may add to the knowledge base usefully applicable to the design of the high-speed mouldboard.

The Moon, as the celestial body closest to Earth, is a prime target for human deep space exploration. China's Lunar Exploration Project IV aims to explore and sample the lunar polar region's water-containing regolith. To effectively simulate the characteristics of this watery lunar regolith, this paper proposes a deep low-temperature preparation system. The feasibility of the system design is validated through theoretical and methodological analysis, including cold source selection, heat dissipation analysis, and energy consumption calculations. Subsequently, a deep low-temperature aqueous lunar regolith preparation system was developed, and tests were conducted to verify its performance. The results confirm that the system can generate water-containing lunar regolith at -238 degrees C and maintain its temperature during drilling. This capability is significant for subsequent research on the drilling performance of deep low-temperature watery lunar regolith.

Water ice is an important water source in lunar polar soil. Drilling and sampling lunar polar soil are important engineering tasks of lunar exploration. In view of the influence of temperature rise on the quality of samples obtained by drilling, the heat transfer and temperature rise in drilled ice-containing lunar soil were investigated. In this study, a thermal simulation model for drilling lunar soil was established based on the discrete element method (DEM). Simulations of the drilling temperature of lunar soil containing ice at 3-5% were performed assuming normal pressure and low temperature. After validating the feasibility and accuracy of the simulation method, the temperatures of the drilling tools and lunar soil were analyzed. Furthermore, drilling in a vacuum was simulated as well, and the results indicated that ice sublimation was negligible for reasonable drilling procedures in the current study.