The remarkable ability of titanium alloys to preserve their superior physical and chemical characteristics when subjected to extreme conditions significantly enhances their importance in the aerospace,military,and med...The remarkable ability of titanium alloys to preserve their superior physical and chemical characteristics when subjected to extreme conditions significantly enhances their importance in the aerospace,military,and medical sectors.However,conventional machining of titanium alloys leads to elevated tool wear,development of surface defects,and reduced machining efficiency due to their low heat conductivity,and chemical affinity.These issues can be somewhat counteracted by integrating ultrasonic vibration in the conventional machining of titanium alloys and also enhance sustainability.This review article offers a holistic evaluation of the influence of ultrasonic vibration-assisted milling and turning on cutting forces,temperature,tool wear,and surface integrity,encompassing surface morphology,surface roughness,surface residual stress,surface hardness,and surface tribological properties during titanium alloys machining.Furthermore,it investigates the sustainability aspect that has not been previously examined.Studies on the performance of ultrasonic-assisted cutting revealed several advantages,including decreased cutting forces and cutting temperature,improved tool life,and a better-machined surface during machining.Consequently,the sustainability factor is improved due to minimized energy consumption and residual waste.In conclusion,the key challenges and future prospects in the ultrasonic-assisted cutting of titanium alloys are also discussed.This review article provides beneficial knowledge for manufactur-ers and researchers regarding ultrasonic vibration-assisted cutting of titanium alloy and will play an important role in achieving sustainability in the industry.展开更多
With the widespread adoption of ultra-precision machining(UPM)in manufacturing,accurately monitoring the temperature within micro-scale cutting zones has become crucial for ensuring machining quality and tool longevit...With the widespread adoption of ultra-precision machining(UPM)in manufacturing,accurately monitoring the temperature within micro-scale cutting zones has become crucial for ensuring machining quality and tool longevity.This review comprehensively evaluates modern in-process cutting temperature measurement methods,comparing conventional approaches and emerging technologies.Thermal conduction-based and radiation-based measurement paradigms are analyzed in terms of their merits,limitations,and domain-specific applicability,particularly with regard to the unique challenges involving micro-scale cutting zones in UPM.Special emphasis is placed on micro-scale sensor-integrated tools and self-sensing tools that enable real-time thermal monitoring at cutting edges.Furthermore,we explore thermal monitoring and management techniques for atomic and close-to-atomic scale manufacturing(ACSM),as well as the transformative potential of emerging technologies like artificial intelligence(AI),internet of things(IoT),and data fusion for machining temperature measurement.This review may serve as a reference for UPM cutting temperature measurement research,helping foster the development of optimized process control technologies.展开更多
A centrifugal pump with a specific speed ns=67 is considered in this study to investigate the impact of blade cutting(at the outlet edge)on the fluid-induced noise,while keeping all the other geometric parameters unch...A centrifugal pump with a specific speed ns=67 is considered in this study to investigate the impact of blade cutting(at the outlet edge)on the fluid-induced noise,while keeping all the other geometric parameters unchanged.The required unsteady numerical calculations are conducted by applying the RNG k-εturbulence model with the volute dipole being used as the sound source.The results indicate that the internal pressure energy of the centrifugal pump essentially depends on the blade passing frequency and its low-frequency harmonic frequency.Moreover,the pressure pulsation distribution directly affects the noise caused by the centrifugal pump.The sound pressure inside and outside the centrifugal pump and the sound power at the blade passing frequency gradually decrease increasing cutting distance of the impeller blades.When the cutting percentage is 1.21%,that is,the clearance ratio between impeller blade and tongue is 8.57%,the comprehensive performance of the centrifugal pump is the best.展开更多
Have we ever seen such a shocking garment in the fashion industry?A down jacket that claims to be one but uses absolutely no down,yet possesses remarkable heating and insulating properties,all designed with a colorles...Have we ever seen such a shocking garment in the fashion industry?A down jacket that claims to be one but uses absolutely no down,yet possesses remarkable heating and insulating properties,all designed with a colorless aesthetic.It resembles clothing that has come from the future.The secret behind this captivating design lies in"SOLAMENTR■"developed by Sumitomo Metal Mining Co.,Ltd.展开更多
Real-time identification of rock strength and cuttability based on monitoring while cutting during excavation is essential for key procedures such as the precise adjustment of excavation parameters and the in-situ mod...Real-time identification of rock strength and cuttability based on monitoring while cutting during excavation is essential for key procedures such as the precise adjustment of excavation parameters and the in-situ modification of hard rocks.This study proposes an in-telligent approach for predicting rock strength and cuttability.A database comprising 132 data sets is established,containing cutting para-meters(such as cutting depth and pick angle),cutting responses(such as specific energy and instantaneous cutting rate),and rock mech-anical parameters collected from conical pick-cutting experiments.These parameters serve as input features for predicting the uniaxial compressive strength and tensile strength of rocks using regression fitting and machine learning methodologies.In addition,rock cuttabil-ity is classified using a combination of the analytic hierarchy process and fuzzy comprehensive evaluation method,and subsequently iden-tified through machine learning approaches.Various models are compared to determine the optimal predictive and classification models.The results indicate that the optimal model for uniaxial compressive strength and tensile strength prediction is the genetic algorithm-optimized backpropagation neural network model,and the optimal model for rock cuttability classification is the radial basis neural network model.展开更多
The water conductivity of karst collapsed column is affected by multiple factors such as the characteristics of its own column filling,structure and mining disturbance.As a structural water-conducting channel,fault us...The water conductivity of karst collapsed column is affected by multiple factors such as the characteristics of its own column filling,structure and mining disturbance.As a structural water-conducting channel,fault usually plays a controlling role in hydrogeological structure.During the process of mine water hazard prevention and control,it was discovered that the lithology composition,compaction and cementation degree and water physical properties of karst collapsed column fillings were all non-conducting water,but due to the influence of combined development faults,some exploration drill holes showed concentrated water outflow.Based on this,the scientific hypothesis was proposed that fault cutting leads to water conduction in karst collapsed columns.The study comprehensively used methods like chronology,exploration data analysis,and hydrochemical testing to analyze the chronological relationship between faults and karst collapsed columns,their spatial relationship,outlet point distribution and water chemical properties,and the impact of faults on the water-conductivity of karst collapsed columns,which proved the effect of fault cutting on changing water conductivity of karst collapsed column.The research showed that later fault cutting through karst collapsed columns turned the originally non-conductive karst collapsed columns into water-conductive collapsed columns at the fault plane,creating a longitudinally connected water-conducting channel.A new model of fault cutting karst collapsed column to change the original water conductivity of karst collapsed column was proposed.The research results can provide a theoretical basis for the prediction of the water conductivity of the karst collapsed column.According to whether the karst collapsed column was cut by the fault,it was predicted theoretically,so as to determine the key areas of water conductivity detection and prevention and control,and has broad application prospects under the background of source control of mine water disaster.展开更多
During the excavation process of deep hard rock tunnels,precutting rock with an abrasive water jet can weaken their strength and improve the efficiency of mining machinery.However,owing to the complex geological envir...During the excavation process of deep hard rock tunnels,precutting rock with an abrasive water jet can weaken their strength and improve the efficiency of mining machinery.However,owing to the complex geological environment,abrasive jets cannot fully utilize their rock-cutting performance.To fully exploit the advantages of high-pressure abrasive water jets,five orthogonal experiments were designed for rocks with significant differences in strength.Experimental research has been conducted on the performance of rotating abrasive waterjet-cutting rocks.Moreover,a neural network prediction model for predicting rock-cutting characteristics is established by comprehensively considering rock mechanics parameters and abrasive water jet parameters.The results show that the cutting depth of rocks with different strengths increases nonlinearly with increasing work pressure of the abrasive water jet.The cutting depth decreases exponentially with increasing cutting velocity.The cutting depth first increases and then decreases with increasing target distance,and the best target distance is between 4 mm and 6 mm.The effect of the target distance on the cutting width of rock is the most significant,but the cutting width of high-strength rock is not sensitive to changes in the working parameters of the abrasive water jet.The average relative errors of BP(backpropagation)neural networks optimized by global optimization algorithms in predicting rock cutting depth and width are 13.3%and 5.4%,respectively.This research combines the working characteristics of mining machinery to study the performance of abrasive waterjet rotary cutting of rocks and constructs a predictive model for the performance of abrasive waterjet cutting of rocks that includes rock strength factors.This provides a new solution for quickly adjusting the working parameters of abrasive water jets according to mining conditions.展开更多
The fatigue resistance of casting polyurethane(CPU)is crucial in various sectors,such as construction,healthcare,and the automotive industry.Despite its importance,no studies have reported on the fatigue threshold of ...The fatigue resistance of casting polyurethane(CPU)is crucial in various sectors,such as construction,healthcare,and the automotive industry.Despite its importance,no studies have reported on the fatigue threshold of CPU.This study employed an advanced Intrinsic Strength Analyzer(ISA)to evaluate the fatigue threshold of CPUs,systematically exploring the effects of three types of isocyanates(PPDI,NDI,TDI)that contribute to hard segment structures based on the cutting method.Employing multiple advanced characterization techniques(XRD,TEM,DSC,AFM),the results indicate that PPDI-based polyurethane exhibits the highest fatigue threshold(182.89 J/m^(2))due to a highest phase separation and a densely packed spherulitic structure,although the hydrogen bonding degree is the lowest(48.3%).Conversely,NDI-based polyurethane,despite having the high hydrogen bonding degree(53.6%),exhibits moderate fatigue performance(122.52 J/m^(2)),likely due to a more scattered microstructure.TDI-based polyurethane,with the highest hydrogen bonding degree(59.1%)but absence of spherulitic structure,shows the lowest fatigue threshold(46.43 J/m^(2)).Compared to common rubbers(NR,NBR,EPDM,BR),the superior fatigue performance of CPU is attributed to its well-organized microstructure,polyurethane possesses a higher fatigue threshold due to its high phase separation degree and orderly and dense spherulitic structure which enhances energy dissipation and reduces crack propagation.展开更多
Vibration cutting has emerged as a promising method for creating surface functional microstructures.However,achieving precise tool setting is a time-consuming process that significantly impacts process efficiency.This...Vibration cutting has emerged as a promising method for creating surface functional microstructures.However,achieving precise tool setting is a time-consuming process that significantly impacts process efficiency.This study proposes an intelligent approach for tool setting in vibration cutting using machine vision and hearing,divided into two steps.In the first step,machine vision is employed to achieve rough precision in tool setting within tens of micrometers.Subsequently,in the second step,machine hearing utilizes sound pickup to capture vibration audio signals,enabling fine tool adjustment within 1μm precision.The relationship between the spectral intensity of vibration audio and cutting depth is analyzed to establish criteria for tool–workpiece contact.Finally,the efficacy of this approach is validated on an ultra-precision platform,demonstrating that the automated tool-setting process takes no more than 74 s.The total cost of the vision and hearing sensors is less than$1500.展开更多
The 3rd China International Supply Chain Expo(hereinafter referred to as the CISCE)is approaching,and NEXWISE Intelligence China Limited(hereinaf ter refer red to as NEXWISE Intelligence),a repeat exhibitor at the eve...The 3rd China International Supply Chain Expo(hereinafter referred to as the CISCE)is approaching,and NEXWISE Intelligence China Limited(hereinaf ter refer red to as NEXWISE Intelligence),a repeat exhibitor at the event,is ready for the show.In the E4 Hall’s Digital Technology Exhibition Zone,this AI-focused company will showcase its two flagship products and technology systems:“Zhang An Xing”Smart Security and“KuberAI(Producer Platform)”Computing Power Foundation,demonstrating China’s innovative AIdriven efforts in empowering industrial chain security.展开更多
High-speed milling(HSM)is advantageous for machining high-quality complex-structure surface components with various materials.Identifying and estimating cutting force signals for characterizing HSM is of high signific...High-speed milling(HSM)is advantageous for machining high-quality complex-structure surface components with various materials.Identifying and estimating cutting force signals for characterizing HSM is of high significance.However,considering the tool runout and size effects,many proposed models focus on the material and mechanical characteristics.This study presents a novel approach for predicting micromilling cutting forces using a semianalytical multidimensional model that integrates experimental empirical data and a mechanical theoretical force model.A novel analytical optimization approach is provided to identify the cutting forces,classify the cutting states,and determine the tool runout using an adaptive algorithm that simplifies modeling and calculation.The instantaneous un-deformed chip thickness(IUCT)is determined from the trochoidal trajectories of each tool flute and optimized using the bisection method.Herein,the computational efficiency is improved,and the errors are clarified.The tool runout parameters are identified from the processed displacement signals and determined from the preprocessed vibration signals using an adaptive signal processing method.It is reliable and stable for determining tool runout and is an effective foundation for the force model.This approach is verified using HSM tests.Herein,the determination coefficients are stable above 0.9.It is convenient and efficient for achieving the key intermediate parameters(IUCT and tool runout),which can be generalized to various machining conditions and operations.展开更多
It is generally believed that cuttings have a significant impact on the forces of tubular string in extended-reach drilling.However,there are few studies attempted to investigate and quantify it.In this paper,a three-...It is generally believed that cuttings have a significant impact on the forces of tubular string in extended-reach drilling.However,there are few studies attempted to investigate and quantify it.In this paper,a three-layer transient model for cuttings transport is established to simulate the characteristics of dynamic cuttings transport over time under various conditions.The simulation results indicate that the change in drilling parameters like ROP(rate of penetration)and flow rate of drilling fluid will lead to the non-uniform distribution of cuttings bed.And the alternation of drilling and circulation will lead to a clear wavy distribution of cuttings bed in the wellbore.Then,the effect of cuttings on tubular string is obtained through a large number of numerical simulations and the nonlinear regression method,and this influence is introduced into the conventional stiff rod model of tubular string.Finally,the transient model for cuttings transport is coupled with the modified tubular mechanic model and applies to a case study of extended-reach drilling.The results show that there is a delay effect for the effect of the changes in drilling parameters on the ground torques because the changes in drilling parameters occur instantaneously,while the changes in cuttings bed distribution are slow due to its low transport velocity.Based on the coupling analysis of transient cuttings transport and tubular mechanical behaviors,the drilling parameters are optimized,including the recommended adjustment period and adjustment range for the ROP,the proper drilling time for the increased flow rate.Furthermore,the circulation and back reaming are optimized.For circulation,the keys are choosing appropriate time interval between the two adjacent circulations and the time for each circulation.To avoid pipe stuck,at least 20 min of circulation is required to remove the cuttings bed near the large-sized BHA((Bottom Hole Assembly))before back reaming,and the maximum back reaming velocity should be smaller than the minimum transport velocity of the uniform bed.展开更多
Recent advancements in drilling technology have driven substantial progress in cuttings removal tool development,particularly for addressing borehole cleaning challenges in highly deviated directional critical factors...Recent advancements in drilling technology have driven substantial progress in cuttings removal tool development,particularly for addressing borehole cleaning challenges in highly deviated directional critical factors in operational safety and efficiency improvement.Despite these innovations,two fundamental challenges persist:an incomplete understanding of mechanistic cuttings removal processes and an insufficient methodological framework for optimal tool installation.Studying the installation positions and assessing the effects of two cuttings removal are essential steps to advance the application of such tools.This investigation was initiated with a comprehensive analysis of particle settling dynamics and migration behaviors in annular wellbore spaces.Building upon Moore's terminal settling velocity equation,a modified model was developed to characterize the transport patterns of cuttings.Through model integration,the precise positioning of the efficient Vortex Cuttings Removal Tool(VCRT)was determined at 188 m from the bit.Subsequently,Computational Fluid Dynamics(CFD)numerical simulation was employed to reveal distinct annular flow field characteristics between VCRT and conventional drilling tools.Field validation in Well Z401X demonstrated a strong correlation between empirical measurements and simulated predictions,with pressure drop deviations of 6.25%and rotational speed variances limited to 7.50%.Analytical results confirmed VCRT's superior performance,exhibited 36.43%reductions in cuttings accumulation at the wellbore's lower quadrant compared to conventional drilling tools.The application of VCRT accelerated cuttings migration velocity in the annular space,significantly increasing the volume of returned onsite cuttings.Friction resistance decreased by approximately 35.90%,indicating higher cuttings removal efficiency than conventional drilling tools.展开更多
[Objective] The experiment was aimed to select effective and economical media for container seedling of triploid clones of Populus tomentosa that was carried out. [Method] The sandy loam, peat, perlite, vermiculite, r...[Objective] The experiment was aimed to select effective and economical media for container seedling of triploid clones of Populus tomentosa that was carried out. [Method] The sandy loam, peat, perlite, vermiculite, riversand, sludge were taken as media of hardwood cutting and survival rate, seedling height were taken as indexes to select media for container seedling of triploid clones of Populus tomentosa. [Result] Different mixedmedia had great influence on survival rates of container seedlings. Taking peat and vermiculite with the proportion of 5∶2 (M10) or peat ,vermiculite with the proportion of 7∶2 (M11) or sandy loam (M1) as media would generate higher cutting survival rate that was higher than 90.0%. There were significant differece in height increments of container seedlings. Taking sandy loam, peat and vermiculite with the proportion of 6∶2∶2(M5)or sandy loam (M1), seedling height of 60-days the seedling was over 37.0 cm. [Conclusion] According to cost analysis of nursery medium, the optimum medium for hardwood cuttings container seedling-raising of triploid clones of Populus tomentosa was sandy loam.展开更多
At present, most commercial computer-aided manufacturing （CAM） systems are deficient in efficiency and performances on generating tool path during machining impellers. To solve the problem, this article develops a s...At present, most commercial computer-aided manufacturing （CAM） systems are deficient in efficiency and performances on generating tool path during machining impellers. To solve the problem, this article develops a special software to plan cutting path for ruled surface impellers. An approximation algorithm to generate cutting path for machining integral ruled surface impellers is proposed. By fitting sampling data points of an impeller blade into a curve, a model of ruled surface blade of an impeller is built up. Furthermore, by calculating the points where the cutter axis vector intersects the free-form hub surface of an impeller, problems about, for instance, the ambiguity in calculation and machining the wide blade surface with a short flute cutter are solved. Finally, an integral impeller cutting path is planned by way of an integrated cutter location control algorithm. Simulation and machining tests with an impeller are performed on a 5-axis computer numerically controlled （CNC） mill machine, which shows the feasibility of the proposed algorithm.展开更多
The high temperature split Hopkinson pressure bar （SHPB） compression experiment is conducted to obtain the data relationship among strain, strain rate and flow stress from room temperature to 550 C for aeronautical ...The high temperature split Hopkinson pressure bar （SHPB） compression experiment is conducted to obtain the data relationship among strain, strain rate and flow stress from room temperature to 550 C for aeronautical aluminum alloy 7050-T7451. Combined high-speed orthogonal cutting experiments with the cutting process simulations, the data relationship of high temperature, high strain rate and large strain in high-speed cutting is modified. The Johnson-Cook empirical model considering the effects of strain hardening, strain rate hardening and thermal softening is selected to describe the data relationship in high-speed cutting, and the material constants of flow stress constitutive model for aluminum alloy 7050-T7451 are determined. Finally, the constitutive model of aluminum alloy 7050-T7451 is established through experiment and simulation verification in high-speed cutting. The model is proved to be reasonable by matching the measured values of the cutting force with the estimated results from FEM simulations.展开更多
A computer aided measurement system is used to measure the cutting temperature directly in high-speed machining by natural thermocouples and standard thermocouples. In this system the tool/workpiece interface temperat...A computer aided measurement system is used to measure the cutting temperature directly in high-speed machining by natural thermocouples and standard thermocouples. In this system the tool/workpiece interface temperature is measured by the tool/workpiece natural thermocouple, while the temperature distribution on the workpiece surface and that of interior are measured by some standard thermocouples prearranged at proper positions. The system can be used to measure cutting temperature in the machining with the rotary cutting tools, such as vertical drill and end milling cutter. It is practically used for the research on high-speed milling with hardened steel.展开更多
In machining the particle reinforced aluminum based composite material with high Si content using the cobalt-cemented tungsten carbide micro cutting tools, diamond like carbon （DLC） films are deposited on cobalt-cem...In machining the particle reinforced aluminum based composite material with high Si content using the cobalt-cemented tungsten carbide micro cutting tools, diamond like carbon （DLC） films are deposited on cobalt-cemented tungsten carbide micro-drills with two-step pretreatment method. Characteristics of DLC coated tools are investigated in bias-enhanced HFCVD system with the optimized hot filament arrangement. The optimization deposition technology is obtained and the wear mechanism of cutting tools is analyzed. The drilling performance of DLC coated tools is verified by the experiments of cutting particle reinforced aluminum based composite material （Si 15% in volume） compared with uncoated ones. Experimental results show that the two-step pretreatment method is appropriate for complex shaped cemented carbide substrates and ensures the good adhesive strength between the diamond film and the substrate. The cutting performance of DLC coated tool is enhanced 10 times when machining the Si particle reinforced aluminum based metal matrix composite compared with that of uncoated ones under the same cutting conditions.展开更多
[Objective] The experiment aimed to provide technical guidance for cutting propagation of forage maize SAUMZI.[Method]The survival situation of cuttings at different stem parts and with different internodes numbers an...[Objective] The experiment aimed to provide technical guidance for cutting propagation of forage maize SAUMZI.[Method]The survival situation of cuttings at different stem parts and with different internodes numbers and nutrient basis of cutting growth were studied in this experiment.[Result]The survival of young cutting was high while the rooting rate,germination rate and soluble sugar content of lower part of old stem and young cutting were all high.The rooting rate and survival rate with two nodes were higher than those with one node.The total nitrogen content in young stem and in all stems of two-year-old strain were relatively high while soluble sugar content was positively correlated to germination rate,however,total nitrogen content did not show obvious correlation with rooting rate and germination rate.[Conclusion]The young cutting possessed the highest survival rate and germination rate.展开更多
[Objective] The research aimed to discuss the effects on rooting,physiological and biochemical indicators of Bougainvillea spectabilis cuttings by remaining leaf combining with soaking cuttings in IBA.[Method] Effects...[Objective] The research aimed to discuss the effects on rooting,physiological and biochemical indicators of Bougainvillea spectabilis cuttings by remaining leaf combining with soaking cuttings in IBA.[Method] Effects of remaining leaf combining with IBA on rooting,physiological and biochemical indicators of B.spectabilis cuttings were studied under the regulation and control of intelligent seed propagation system,and then set four treatments：remaining leaf combining with soaking in clean water,remaining leaf combining with soaking in IBA,defoliation combining soaking in clean water,and defoliation combining with soaking in IBA.[Result] The soluble sugar content was high,but indoleacetic acid oxidase activity was lower in the initial stage of adventitious root differentiation in treatment of remaining leaf.While the rooting number,root length,the root mass growth and survival rate of cutting were obviously higher than that in treatment of defoliation.Compared to the treatment soaking in clean water,the treatment soaking in 500×10^-6 IBA increased the soluble sugar content in leaves of cuttings and enhanced rooting of cuttings.[Conclusion] The survival rate and rooting of cuttings improved obviously in the treatment of remaining leaf combining with soaking in 500×10^-6 IBA before cutting under the regulation and control of intelligent seed propagation system.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.92160301,92060203,52175415 and 52205475)the Science Center for Gas Turbine Project(No.P2023-B-IV-003-001)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK20210295)the Huaqiao University Engineering Research Center of Brittle Materials Machining(MOE,2023IME-001)。
文摘The remarkable ability of titanium alloys to preserve their superior physical and chemical characteristics when subjected to extreme conditions significantly enhances their importance in the aerospace,military,and medical sectors.However,conventional machining of titanium alloys leads to elevated tool wear,development of surface defects,and reduced machining efficiency due to their low heat conductivity,and chemical affinity.These issues can be somewhat counteracted by integrating ultrasonic vibration in the conventional machining of titanium alloys and also enhance sustainability.This review article offers a holistic evaluation of the influence of ultrasonic vibration-assisted milling and turning on cutting forces,temperature,tool wear,and surface integrity,encompassing surface morphology,surface roughness,surface residual stress,surface hardness,and surface tribological properties during titanium alloys machining.Furthermore,it investigates the sustainability aspect that has not been previously examined.Studies on the performance of ultrasonic-assisted cutting revealed several advantages,including decreased cutting forces and cutting temperature,improved tool life,and a better-machined surface during machining.Consequently,the sustainability factor is improved due to minimized energy consumption and residual waste.In conclusion,the key challenges and future prospects in the ultrasonic-assisted cutting of titanium alloys are also discussed.This review article provides beneficial knowledge for manufactur-ers and researchers regarding ultrasonic vibration-assisted cutting of titanium alloy and will play an important role in achieving sustainability in the industry.
基金supported by the National Natural Science Foundation of China(Nos.52425505 and U22A20207)the National Key R&D Program of China(No.2022YFB3403302)the Zhejiang Provincial Key R&D Program of China(No.2023C01056).
文摘With the widespread adoption of ultra-precision machining(UPM)in manufacturing,accurately monitoring the temperature within micro-scale cutting zones has become crucial for ensuring machining quality and tool longevity.This review comprehensively evaluates modern in-process cutting temperature measurement methods,comparing conventional approaches and emerging technologies.Thermal conduction-based and radiation-based measurement paradigms are analyzed in terms of their merits,limitations,and domain-specific applicability,particularly with regard to the unique challenges involving micro-scale cutting zones in UPM.Special emphasis is placed on micro-scale sensor-integrated tools and self-sensing tools that enable real-time thermal monitoring at cutting edges.Furthermore,we explore thermal monitoring and management techniques for atomic and close-to-atomic scale manufacturing(ACSM),as well as the transformative potential of emerging technologies like artificial intelligence(AI),internet of things(IoT),and data fusion for machining temperature measurement.This review may serve as a reference for UPM cutting temperature measurement research,helping foster the development of optimized process control technologies.
文摘A centrifugal pump with a specific speed ns=67 is considered in this study to investigate the impact of blade cutting(at the outlet edge)on the fluid-induced noise,while keeping all the other geometric parameters unchanged.The required unsteady numerical calculations are conducted by applying the RNG k-εturbulence model with the volute dipole being used as the sound source.The results indicate that the internal pressure energy of the centrifugal pump essentially depends on the blade passing frequency and its low-frequency harmonic frequency.Moreover,the pressure pulsation distribution directly affects the noise caused by the centrifugal pump.The sound pressure inside and outside the centrifugal pump and the sound power at the blade passing frequency gradually decrease increasing cutting distance of the impeller blades.When the cutting percentage is 1.21%,that is,the clearance ratio between impeller blade and tongue is 8.57%,the comprehensive performance of the centrifugal pump is the best.
文摘Have we ever seen such a shocking garment in the fashion industry?A down jacket that claims to be one but uses absolutely no down,yet possesses remarkable heating and insulating properties,all designed with a colorless aesthetic.It resembles clothing that has come from the future.The secret behind this captivating design lies in"SOLAMENTR■"developed by Sumitomo Metal Mining Co.,Ltd.
基金supported by the National Natural Science Foundation of China(Nos.52174099 and 52474168)the Science and Technology Innovation Program of Hunan Province,China(No.2023RC3050)+1 种基金the Natural Science Foundation of Hunan,China(No.2024JJ4064)the Open Fund of the State Key Laboratory of Safety Technology of Metal Mines(No.kfkt2023-01).
文摘Real-time identification of rock strength and cuttability based on monitoring while cutting during excavation is essential for key procedures such as the precise adjustment of excavation parameters and the in-situ modification of hard rocks.This study proposes an in-telligent approach for predicting rock strength and cuttability.A database comprising 132 data sets is established,containing cutting para-meters(such as cutting depth and pick angle),cutting responses(such as specific energy and instantaneous cutting rate),and rock mech-anical parameters collected from conical pick-cutting experiments.These parameters serve as input features for predicting the uniaxial compressive strength and tensile strength of rocks using regression fitting and machine learning methodologies.In addition,rock cuttabil-ity is classified using a combination of the analytic hierarchy process and fuzzy comprehensive evaluation method,and subsequently iden-tified through machine learning approaches.Various models are compared to determine the optimal predictive and classification models.The results indicate that the optimal model for uniaxial compressive strength and tensile strength prediction is the genetic algorithm-optimized backpropagation neural network model,and the optimal model for rock cuttability classification is the radial basis neural network model.
基金supported by the Postdoctoral Fellowship Program of CPSF(No.GZC20233005)the Fundamental Research Funds for the Central Universities(No.2024QN11025)+1 种基金the General Program of National Natural Science Foundation of China(No.52274243)the Hebei Province Natural Science Foundation Ecological Wisdom Mine Joint Fund Project(Nos.D2020402013 and D2022402040)。
文摘The water conductivity of karst collapsed column is affected by multiple factors such as the characteristics of its own column filling,structure and mining disturbance.As a structural water-conducting channel,fault usually plays a controlling role in hydrogeological structure.During the process of mine water hazard prevention and control,it was discovered that the lithology composition,compaction and cementation degree and water physical properties of karst collapsed column fillings were all non-conducting water,but due to the influence of combined development faults,some exploration drill holes showed concentrated water outflow.Based on this,the scientific hypothesis was proposed that fault cutting leads to water conduction in karst collapsed columns.The study comprehensively used methods like chronology,exploration data analysis,and hydrochemical testing to analyze the chronological relationship between faults and karst collapsed columns,their spatial relationship,outlet point distribution and water chemical properties,and the impact of faults on the water-conductivity of karst collapsed columns,which proved the effect of fault cutting on changing water conductivity of karst collapsed column.The research showed that later fault cutting through karst collapsed columns turned the originally non-conductive karst collapsed columns into water-conductive collapsed columns at the fault plane,creating a longitudinally connected water-conducting channel.A new model of fault cutting karst collapsed column to change the original water conductivity of karst collapsed column was proposed.The research results can provide a theoretical basis for the prediction of the water conductivity of the karst collapsed column.According to whether the karst collapsed column was cut by the fault,it was predicted theoretically,so as to determine the key areas of water conductivity detection and prevention and control,and has broad application prospects under the background of source control of mine water disaster.
基金Supported by Jiangsu Provincial Natural Science Foundation(Grant No.BK20231497)Jiangsu Provincial Post Graduate Research&Practice Innovation Program(Grant No.KYCX25_2982)+2 种基金China University of Mining and Technology Graduate Innovation Program(Grant No.2025WLKXJ094)National Natural Science Foundation of China(Grant No.51975573),National Key R&D Program of China(Grant No.2022YFC2905600)Priority Academic Program Development of Jiangsu Higher Education Institute of China.
文摘During the excavation process of deep hard rock tunnels,precutting rock with an abrasive water jet can weaken their strength and improve the efficiency of mining machinery.However,owing to the complex geological environment,abrasive jets cannot fully utilize their rock-cutting performance.To fully exploit the advantages of high-pressure abrasive water jets,five orthogonal experiments were designed for rocks with significant differences in strength.Experimental research has been conducted on the performance of rotating abrasive waterjet-cutting rocks.Moreover,a neural network prediction model for predicting rock-cutting characteristics is established by comprehensively considering rock mechanics parameters and abrasive water jet parameters.The results show that the cutting depth of rocks with different strengths increases nonlinearly with increasing work pressure of the abrasive water jet.The cutting depth decreases exponentially with increasing cutting velocity.The cutting depth first increases and then decreases with increasing target distance,and the best target distance is between 4 mm and 6 mm.The effect of the target distance on the cutting width of rock is the most significant,but the cutting width of high-strength rock is not sensitive to changes in the working parameters of the abrasive water jet.The average relative errors of BP(backpropagation)neural networks optimized by global optimization algorithms in predicting rock cutting depth and width are 13.3%and 5.4%,respectively.This research combines the working characteristics of mining machinery to study the performance of abrasive waterjet rotary cutting of rocks and constructs a predictive model for the performance of abrasive waterjet cutting of rocks that includes rock strength factors.This provides a new solution for quickly adjusting the working parameters of abrasive water jets according to mining conditions.
基金financially supported by the National Natural Science Foundation of China(No.52473228).
文摘The fatigue resistance of casting polyurethane(CPU)is crucial in various sectors,such as construction,healthcare,and the automotive industry.Despite its importance,no studies have reported on the fatigue threshold of CPU.This study employed an advanced Intrinsic Strength Analyzer(ISA)to evaluate the fatigue threshold of CPUs,systematically exploring the effects of three types of isocyanates(PPDI,NDI,TDI)that contribute to hard segment structures based on the cutting method.Employing multiple advanced characterization techniques(XRD,TEM,DSC,AFM),the results indicate that PPDI-based polyurethane exhibits the highest fatigue threshold(182.89 J/m^(2))due to a highest phase separation and a densely packed spherulitic structure,although the hydrogen bonding degree is the lowest(48.3%).Conversely,NDI-based polyurethane,despite having the high hydrogen bonding degree(53.6%),exhibits moderate fatigue performance(122.52 J/m^(2)),likely due to a more scattered microstructure.TDI-based polyurethane,with the highest hydrogen bonding degree(59.1%)but absence of spherulitic structure,shows the lowest fatigue threshold(46.43 J/m^(2)).Compared to common rubbers(NR,NBR,EPDM,BR),the superior fatigue performance of CPU is attributed to its well-organized microstructure,polyurethane possesses a higher fatigue threshold due to its high phase separation degree and orderly and dense spherulitic structure which enhances energy dissipation and reduces crack propagation.
基金the financial support for this research provided by the National Natural Science Foundation of China(Grant Nos.52275470,124115301,and 52105458)the Natural Science Foundation of Beijing(Grant No.3222009).
文摘Vibration cutting has emerged as a promising method for creating surface functional microstructures.However,achieving precise tool setting is a time-consuming process that significantly impacts process efficiency.This study proposes an intelligent approach for tool setting in vibration cutting using machine vision and hearing,divided into two steps.In the first step,machine vision is employed to achieve rough precision in tool setting within tens of micrometers.Subsequently,in the second step,machine hearing utilizes sound pickup to capture vibration audio signals,enabling fine tool adjustment within 1μm precision.The relationship between the spectral intensity of vibration audio and cutting depth is analyzed to establish criteria for tool–workpiece contact.Finally,the efficacy of this approach is validated on an ultra-precision platform,demonstrating that the automated tool-setting process takes no more than 74 s.The total cost of the vision and hearing sensors is less than$1500.
文摘The 3rd China International Supply Chain Expo(hereinafter referred to as the CISCE)is approaching,and NEXWISE Intelligence China Limited(hereinaf ter refer red to as NEXWISE Intelligence),a repeat exhibitor at the event,is ready for the show.In the E4 Hall’s Digital Technology Exhibition Zone,this AI-focused company will showcase its two flagship products and technology systems:“Zhang An Xing”Smart Security and“KuberAI(Producer Platform)”Computing Power Foundation,demonstrating China’s innovative AIdriven efforts in empowering industrial chain security.
基金Supported by National Natural Science Foundation of China(Grant No.52175528).
文摘High-speed milling(HSM)is advantageous for machining high-quality complex-structure surface components with various materials.Identifying and estimating cutting force signals for characterizing HSM is of high significance.However,considering the tool runout and size effects,many proposed models focus on the material and mechanical characteristics.This study presents a novel approach for predicting micromilling cutting forces using a semianalytical multidimensional model that integrates experimental empirical data and a mechanical theoretical force model.A novel analytical optimization approach is provided to identify the cutting forces,classify the cutting states,and determine the tool runout using an adaptive algorithm that simplifies modeling and calculation.The instantaneous un-deformed chip thickness(IUCT)is determined from the trochoidal trajectories of each tool flute and optimized using the bisection method.Herein,the computational efficiency is improved,and the errors are clarified.The tool runout parameters are identified from the processed displacement signals and determined from the preprocessed vibration signals using an adaptive signal processing method.It is reliable and stable for determining tool runout and is an effective foundation for the force model.This approach is verified using HSM tests.Herein,the determination coefficients are stable above 0.9.It is convenient and efficient for achieving the key intermediate parameters(IUCT and tool runout),which can be generalized to various machining conditions and operations.
基金support from the Natural Science Foundation of China(Grant Nos.52222401,52234002,52394255)National Key Research and Development Program of China(Grant No.2023YFC2810901)Science Foundation of China University of Petroleum,Beijing(Grant No.ZXZX20230083).
文摘It is generally believed that cuttings have a significant impact on the forces of tubular string in extended-reach drilling.However,there are few studies attempted to investigate and quantify it.In this paper,a three-layer transient model for cuttings transport is established to simulate the characteristics of dynamic cuttings transport over time under various conditions.The simulation results indicate that the change in drilling parameters like ROP(rate of penetration)and flow rate of drilling fluid will lead to the non-uniform distribution of cuttings bed.And the alternation of drilling and circulation will lead to a clear wavy distribution of cuttings bed in the wellbore.Then,the effect of cuttings on tubular string is obtained through a large number of numerical simulations and the nonlinear regression method,and this influence is introduced into the conventional stiff rod model of tubular string.Finally,the transient model for cuttings transport is coupled with the modified tubular mechanic model and applies to a case study of extended-reach drilling.The results show that there is a delay effect for the effect of the changes in drilling parameters on the ground torques because the changes in drilling parameters occur instantaneously,while the changes in cuttings bed distribution are slow due to its low transport velocity.Based on the coupling analysis of transient cuttings transport and tubular mechanical behaviors,the drilling parameters are optimized,including the recommended adjustment period and adjustment range for the ROP,the proper drilling time for the increased flow rate.Furthermore,the circulation and back reaming are optimized.For circulation,the keys are choosing appropriate time interval between the two adjacent circulations and the time for each circulation.To avoid pipe stuck,at least 20 min of circulation is required to remove the cuttings bed near the large-sized BHA((Bottom Hole Assembly))before back reaming,and the maximum back reaming velocity should be smaller than the minimum transport velocity of the uniform bed.
基金supported by the National Natural Science Foundation of China(No.52374008,No.52174003)Shanghai Leading Academic Discipline Project(No,S30106).
文摘Recent advancements in drilling technology have driven substantial progress in cuttings removal tool development,particularly for addressing borehole cleaning challenges in highly deviated directional critical factors in operational safety and efficiency improvement.Despite these innovations,two fundamental challenges persist:an incomplete understanding of mechanistic cuttings removal processes and an insufficient methodological framework for optimal tool installation.Studying the installation positions and assessing the effects of two cuttings removal are essential steps to advance the application of such tools.This investigation was initiated with a comprehensive analysis of particle settling dynamics and migration behaviors in annular wellbore spaces.Building upon Moore's terminal settling velocity equation,a modified model was developed to characterize the transport patterns of cuttings.Through model integration,the precise positioning of the efficient Vortex Cuttings Removal Tool(VCRT)was determined at 188 m from the bit.Subsequently,Computational Fluid Dynamics(CFD)numerical simulation was employed to reveal distinct annular flow field characteristics between VCRT and conventional drilling tools.Field validation in Well Z401X demonstrated a strong correlation between empirical measurements and simulated predictions,with pressure drop deviations of 6.25%and rotational speed variances limited to 7.50%.Analytical results confirmed VCRT's superior performance,exhibited 36.43%reductions in cuttings accumulation at the wellbore's lower quadrant compared to conventional drilling tools.The application of VCRT accelerated cuttings migration velocity in the annular space,significantly increasing the volume of returned onsite cuttings.Friction resistance decreased by approximately 35.90%,indicating higher cuttings removal efficiency than conventional drilling tools.
基金Supported by National Key Technology R&D Program during the 11th Five-year Plan Period(2006BAD32B01)~~
文摘[Objective] The experiment was aimed to select effective and economical media for container seedling of triploid clones of Populus tomentosa that was carried out. [Method] The sandy loam, peat, perlite, vermiculite, riversand, sludge were taken as media of hardwood cutting and survival rate, seedling height were taken as indexes to select media for container seedling of triploid clones of Populus tomentosa. [Result] Different mixedmedia had great influence on survival rates of container seedlings. Taking peat and vermiculite with the proportion of 5∶2 (M10) or peat ,vermiculite with the proportion of 7∶2 (M11) or sandy loam (M1) as media would generate higher cutting survival rate that was higher than 90.0%. There were significant differece in height increments of container seedlings. Taking sandy loam, peat and vermiculite with the proportion of 6∶2∶2(M5)or sandy loam (M1), seedling height of 60-days the seedling was over 37.0 cm. [Conclusion] According to cost analysis of nursery medium, the optimum medium for hardwood cuttings container seedling-raising of triploid clones of Populus tomentosa was sandy loam.
基金Key Development Program of Science and Technology of Heilongjiang Province, China (GB05A501)
文摘At present, most commercial computer-aided manufacturing （CAM） systems are deficient in efficiency and performances on generating tool path during machining impellers. To solve the problem, this article develops a special software to plan cutting path for ruled surface impellers. An approximation algorithm to generate cutting path for machining integral ruled surface impellers is proposed. By fitting sampling data points of an impeller blade into a curve, a model of ruled surface blade of an impeller is built up. Furthermore, by calculating the points where the cutter axis vector intersects the free-form hub surface of an impeller, problems about, for instance, the ambiguity in calculation and machining the wide blade surface with a short flute cutter are solved. Finally, an integral impeller cutting path is planned by way of an integrated cutter location control algorithm. Simulation and machining tests with an impeller are performed on a 5-axis computer numerically controlled （CNC） mill machine, which shows the feasibility of the proposed algorithm.
文摘The high temperature split Hopkinson pressure bar （SHPB） compression experiment is conducted to obtain the data relationship among strain, strain rate and flow stress from room temperature to 550 C for aeronautical aluminum alloy 7050-T7451. Combined high-speed orthogonal cutting experiments with the cutting process simulations, the data relationship of high temperature, high strain rate and large strain in high-speed cutting is modified. The Johnson-Cook empirical model considering the effects of strain hardening, strain rate hardening and thermal softening is selected to describe the data relationship in high-speed cutting, and the material constants of flow stress constitutive model for aluminum alloy 7050-T7451 are determined. Finally, the constitutive model of aluminum alloy 7050-T7451 is established through experiment and simulation verification in high-speed cutting. The model is proved to be reasonable by matching the measured values of the cutting force with the estimated results from FEM simulations.
文摘A computer aided measurement system is used to measure the cutting temperature directly in high-speed machining by natural thermocouples and standard thermocouples. In this system the tool/workpiece interface temperature is measured by the tool/workpiece natural thermocouple, while the temperature distribution on the workpiece surface and that of interior are measured by some standard thermocouples prearranged at proper positions. The system can be used to measure cutting temperature in the machining with the rotary cutting tools, such as vertical drill and end milling cutter. It is practically used for the research on high-speed milling with hardened steel.
文摘In machining the particle reinforced aluminum based composite material with high Si content using the cobalt-cemented tungsten carbide micro cutting tools, diamond like carbon （DLC） films are deposited on cobalt-cemented tungsten carbide micro-drills with two-step pretreatment method. Characteristics of DLC coated tools are investigated in bias-enhanced HFCVD system with the optimized hot filament arrangement. The optimization deposition technology is obtained and the wear mechanism of cutting tools is analyzed. The drilling performance of DLC coated tools is verified by the experiments of cutting particle reinforced aluminum based composite material （Si 15% in volume） compared with uncoated ones. Experimental results show that the two-step pretreatment method is appropriate for complex shaped cemented carbide substrates and ensures the good adhesive strength between the diamond film and the substrate. The cutting performance of DLC coated tool is enhanced 10 times when machining the Si particle reinforced aluminum based metal matrix composite compared with that of uncoated ones under the same cutting conditions.
文摘[Objective] The experiment aimed to provide technical guidance for cutting propagation of forage maize SAUMZI.[Method]The survival situation of cuttings at different stem parts and with different internodes numbers and nutrient basis of cutting growth were studied in this experiment.[Result]The survival of young cutting was high while the rooting rate,germination rate and soluble sugar content of lower part of old stem and young cutting were all high.The rooting rate and survival rate with two nodes were higher than those with one node.The total nitrogen content in young stem and in all stems of two-year-old strain were relatively high while soluble sugar content was positively correlated to germination rate,however,total nitrogen content did not show obvious correlation with rooting rate and germination rate.[Conclusion]The young cutting possessed the highest survival rate and germination rate.
基金Supported by Natural Science Foundation of Fujian Province(2008J0052 )Technology Program in Xiamen City(3502Z20072007)~~
文摘[Objective] The research aimed to discuss the effects on rooting,physiological and biochemical indicators of Bougainvillea spectabilis cuttings by remaining leaf combining with soaking cuttings in IBA.[Method] Effects of remaining leaf combining with IBA on rooting,physiological and biochemical indicators of B.spectabilis cuttings were studied under the regulation and control of intelligent seed propagation system,and then set four treatments：remaining leaf combining with soaking in clean water,remaining leaf combining with soaking in IBA,defoliation combining soaking in clean water,and defoliation combining with soaking in IBA.[Result] The soluble sugar content was high,but indoleacetic acid oxidase activity was lower in the initial stage of adventitious root differentiation in treatment of remaining leaf.While the rooting number,root length,the root mass growth and survival rate of cutting were obviously higher than that in treatment of defoliation.Compared to the treatment soaking in clean water,the treatment soaking in 500×10^-6 IBA increased the soluble sugar content in leaves of cuttings and enhanced rooting of cuttings.[Conclusion] The survival rate and rooting of cuttings improved obviously in the treatment of remaining leaf combining with soaking in 500×10^-6 IBA before cutting under the regulation and control of intelligent seed propagation system.
