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Grinding is a crucial process in machining workpieces because it plays a vital role in achieving the desired precision and surface quality. However, a significant technical challenge in grinding is the potential increase in temperature due to high specific energy, which can lead to surface thermal damage. Therefore, ensuring control over the surface integrity of workpieces during grinding becomes a critical concern. This necessitates the development of temperature field models that consider various parameters, such as workpiece materials, grinding wheels, grinding parameters, cooling methods, and media, to guide industrial production. This study thoroughly analyzes and summarizes grinding temperature field models. First, the theory of the grinding temperature field is investigated, classifying it into traditional models based on a continuous belt heat source and those based on a discrete heat source, depending on whether the heat source is uniform and continuous. Through this examination, a more accurate grinding temperature model that closely aligns with practical grinding conditions is derived. Subsequently, various grinding thermal models are summarized, including models for the heat source distribution, energy distribution proportional coefficient, and convective heat transfer coefficient. Through comprehensive research, the most widely recognized, utilized, and accurate model for each category is identified. The application of these grinding thermal models is reviewed, shedding light on the governing laws that dictate the influence of the heat source distribution, heat distribution, and convective heat transfer in the grinding arc zone on the grinding temperature field. Finally, considering the current issues in the field of grinding temperature, potential future research directions are proposed. The aim of this study is to provide theoretical guidance and technical support for predicting workpiece temperature and improving surface integrity. The temperature field is divided into uniform continuous segment and nonuniform discontinuous counterpart. The heat source distribution model is summarized for different cutting depths. The energy proportional coefficient and convective heat transfer coefficient models are summarized. The application and implementation of temperature field and grinding thermal mode are summarized.

This paper examines the engineering background of the main shaft of Ruihai Mining Group Company in Laizhou City, with a focus on the loose permeable stratum located in the frozen section of the shaft. Field measurements and data collection, including brine temperature and surface subsidence values, were conducted using temperature and hydrological boreholes. The distribution of the frozen wall temperature field was then numerically simulated using finite element analysis, and the results were compared and analyzed with field data. Scanning electron microscopy (SEM) was used to qualitatively describe the microstructure of the soft rock in the frozen section under different freezing schemes. Based on the formation of the frozen wall, a new construction scheme for freezing and excavating the internal and external circles of the vertical shaft in the loose permeable stratum is proposed. This involves the implementation of \"inner and outer double-circles of freezing holes\" and a comparison of the freezing effect of the temperature field before and after the improvement. The results indicate that the new freezing scheme can accelerate the freezing rate of the surrounding rock of the shaft, and reduce the time required for closure by more than 10 days. After applying the improved scheme for 60 days, the temperature is lowered by 4–5 ℃ compared to the original scheme, and the thickness of the frozen wall is approximately 4.8 m, significantly thicker than before. These findings demonstrate the effectiveness of adding an inner circle of freezing holes in achieving the lowest temperature which contributes to subsequent shaft excavation. The new scheme holds significant implications for the safe construction of shaft excavation in complex hydrogeological areas.HighlightsThe main shaft in the unique geological conditions and the impact of tidal activities on freezing performance are analyzed.The new construction scheme incorporating \"inner and outer double-circles of freezing holes\" significantly improves freezing efficiency and reduces closure time.The improved scheme results in a thicker frozen wall and lower temperature compared to the original scheme.The findings have important implications for the safe construction of shaft excavation in complex coastal hydrogeological areas.

Lamb wave-based damage detection for large-scale composites is one of the most prosperous structural health monitoring technologies for aircraft structures. However, the temperature has a significant effect on the amplitude and phase of the Lamb wave signal so that temperature compensation is always the focus problem. Especially, it is difficult to identify the damage in the aircraft structures when the temperature is not uniform. In this paper, a compensation method for Lamb wave-based damage detection within a non-uniform temperature field is proposed. Hilbert transform and Levenberg-Marquardt optimization algorithm are developed to extract the amplitude and phase variation caused by the change of temperature, which is used to establish a data-driven model for reconstructing the reference signal at a certain temperature. In the temperature compensation process, the current Lamb wave signal of each exciting-sensing path under the estimated structural condition is substituted into the data-driven model to identify an interpolated initial temperature field, which is further processed by an outlier removing algorithm to eliminate the effect of damage and get the actual non-uniform temperature field. Temperature compensation can be achieved by reconstructing the reference signals within the identified non-uniform temperature field, which are used to compare with the current acquired signals for damage imaging. Both simulation and experiment were conducted to verify the feasibility and effectiveness of the proposed non-uniform temperature field identification and compensation technique for Lamb wave-based structural health monitoring.

The temperature field reconstruction of heat source systems (TFR-HSS) with limited monitoring sensors in thermal management plays an important role in the real-time health detection systems of electronic equipment in engineering. However, prior methods with common interpolations usually cannot provide accurate reconstruction performance as required. In addition, no public dataset exists for the wide research of reconstruction methods to further boost reconstruction performance and engineering applications. To overcome this problem, this work develops a machine learning surrogate modeling benchmark for the TFR-HSS task. First, the TFR-HSS task is mathematically modeled from a real-world engineering problem, and four types of computational modelings are constructed to transform the problem into discrete mapping forms. Then, this work proposes a set of machine learning surrogate modeling methods, including general machine learning methods and deep learning methods, to advance the state-of-the-art methods over temperature field reconstruction. More importantly, this work develops a novel benchmark dataset, namely the temperature field reconstruction dataset (TFRD), to evaluate these machine learning surrogate modeling methods for the TFR-HSS task. Finally, a performance analysis of typical methods is given on the TFRD, which can serve as the baseline results on this benchmark.

In the construction of an F‐type cross‐passage in an overlapping‐type shield tunnel using the artificial ground freezing method, the development of the distal frozen wall is difficult to control, and ground deformation is influenced by the superimposed disturbance of successive construction steps. Existing studies are insufficient to fully characterize the evolution of the frozen temperature field and frozen displacement field. To address this, the F‐type cross‐passage between Lingbi Road Station and Yaoyuan Road Station of Hefei Metro Line 8 adopted measures such as installing inclined freeze pipes for reinforcement and applying time‐sequence construction to control the distal cooling capacity and ground displacement field. Numerical simulation combined with analysis of field test data was conducted to investigate the evolution laws of the frozen temperature field and frozen displacement field in this F‐type cross‐passage. The results indicate that by installing long inclined freeze pipes on both sides of the main frozen reinforcement zone, the minimum thickness of the frozen wall at the control section ( X = −12.03 m) reached 2.51 m after 55 days of active freezing, satisfying the design requirements. At the same time, after 55 days of ground freezing, the soil temperature in the central region of the Y = 0 m section ranged from 2.5°C to −2.5°C. This indicates that the soil was at the critical freezing temperature, which is favorable for the underground excavation of the F‐type cross‐passage. Regarding ground deformation, during both the freezing reinforcement and excavation stages, a pancake‐shaped heave/settlement zone appeared on the surface above the cross‐passage, with slight shifts in its center position. The surface displacement field generally showed a decreasing or increasing trend outward from this central position.

As the mining depth of coal mines continues to increase, the problem of mine heat damage becomes increasingly prominent. In response to the heat damage problem in deep mines, this paper presents a novel approach of mine heat damage control and geothermal resource exploitation under the collaborative effect of extraction and ventilation. Taking Sanhejian Coal Mine in Xuzhou as the research object, numerical simulation is conducted using finite element simulation analysis software to analyze the evolution law of the temperature field of roadway surrounding rock and air in the roadway during the variation of different key factors. Additionally, in the process of continuous tunneling, the optimal cooling scheme for roadways at different locations is obtained. The conclusions are as follows: (1) Treating mine heat damage under pure ventilation has the advantage of rapid cooling speed. The temperature at the observation point in the roadway can be reduced to approximately 283 K at its lowest. However, the disadvantage lies in the large temperature difference before and after the roadway (no less than 7 K) and the need for continuous ventilation. (2) During the extraction process, reducing the average injection water temperature and decreasing the distance from the roadway can effectively enhance the effectiveness of mine heat damage control. Nevertheless, under pure extraction, the temperature reduction rate of roadway surrounding rock is relatively slow. When the distance between the roadway and the injection well does not exceed 30 m and the average injection water temperature does not exceed 190 K, the surrounding rock temperature can be reduced to below 303.15 K within one year. (3) The extraction-ventilation synergy method not only can effectively narrow the temperature difference before and after the roadway but also can improve the temperature reduction speed in the roadway to a certain extent. Moreover, the geothermal resources generated by extraction can also yield certain economic benefits. This research provides a new perspective for cooling the coal mining face of coal mines.

Surface water–groundwater exchange affects the material and energy transfer of rivers and adjacent riparian zones. As an intuitive carrier of energy, temperature can effectively reflect the spatial and temporal variation of surface water–groundwater exchange process. In this paper, the influence of water head variation and sand sample uniformity on its temperature field and seepage field is studied through a one-dimensional sand column laboratory test. To verify the accuracy of the one-dimensional vertical heat analysis model, the vertical seepage velocity measured in the indoor test is compared with the vertical submerged exchange rate calculated by the four analysis models. The results show that the Hatch analytical solution, Keery analytical solution, McCallum analytical solution and Luce analytical solution calculated by VFLUX2 through MATLAB are reliable for calculating the vertical undercurrent exchange rate of the heterogeneous sand column.

The turn-back tunnel of Guangzhou Metro Line 3 Tianhe Station with a large span was excavated in sandy clay which may easily break and disintegrate. The artificial ground freezing (AGF) technique was used to stabilize the soil and to prevent its collapse during excavations. Most of the existing theoretical analysis and numerical simulation on the AGF technique are purely based on a couple of assumptions, which are not able to produce accurate predictions. It would be more accurate for the AGF analysis to include the field monitoring. In this study, the coupled method of the field monitoring, the analytical formula, and the numerical method is used to evaluate the thickness and average temperature of the frozen zone. Field monitoring was conducted to measure the temperature of the brine and the ground. Analytical formula was used to compute the thickness and the average temperature of the frozen zone. Numerical simulation is also carried out to predict the thickness and the temperature field of the frozen zone. According to the analytical and numerical analysis, the computed thickness and average temperature of the frozen zone meet the designed requirements of the project, which are further confirmed by the successful excavation of the tunnel. This indicates that the coupled method used in this paper is reliable and would be helpful for the AGF application in practical engineering.

We solve the magnetostriction strains for B20 helimagnets in the skyrmion crystal phase. By taking MnSi as an example, we reproduce its temperature-magnetic field (T-B) phase diagrams within a thermodynamic potential incorporating magnetoelastic interactions. The calculation shows that the normal strain 33 undergoes a sudden jump through a conical-skyrmion phase transition at any temperature. The corresponding experimental measurements for MnSi agree quantitatively well with the calculation.

Zhangzhou geothermal field is one of the highest temperature in southeastern coastal areas in China. Zhangzhou geothermal field is an uplift-fracture type geothermal resource, and there are several deep fractures in the geothermal field, controlling water flow and heat transfer. Presently there is no systematic study of the characteristics of the temperature field, pressure field and water density distribution in the geothermal field, and there is no systematic analysis of the main factors affecting the temperature field. In this work, geological features of the fracture system are considered, and a conceptual model of the fracture system is established. Based on these, the distribution of the temperature field, pressure field and water density field at Zhangzhou geothermal field are numerically studied, the controlling effect of the fracture system on the temperature field is analyzed, and the main factors affecting the temperature field, pressure field and water density field are discussed. The results indicate that the temperature field and water density field at Zhangzhou geothermal field are strongly controlled by the fracture system, and the zone of high-temperature and low-density is confined within the fracture system. Main factors affecting the temperature field and water density field include the permeability of the fracture zone, the thermal conductivity of rocks and the water recharge rate. Higher fracture zone permeability will reduce the temperature and increase the water density in the center of the fracture system. Higher water recharge rate will increase the temperature and reduce the water density in the center of the fracture system.