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A Novel Model for Describing Rail Weld Irregularities and Predicting Wheel-Rail Forces Using a Machine Learning Approach

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 555-577页

作者： Linlin Sun Zihui Wang Shukun Cui Ziquan Yan Weiping Hu Qingchun Meng State Key Laboratory of high-Speed Railway Track System China Academy of Railway Sciences Corporation LimitedBeijing100081China Railway Engineering Research Institute China Academy of Railway Sciences Corporation LimitedBeijing100081China School of Aeronautic Science and Engineering Beihang UniversityBeijing100191China

Rail weld irregularities are one of the primary excitation sources for vehicle-track interaction dynamics in modern high-speed *** can cause significant wheel-rail dynamic interactions,leading to wheel-rail noise,component damage,and *** researchers have employed the vehicle-track interaction dynamic model to study the dynamic interactions between wheel and rail induced by rail weld geometry ***,the cosine wave model used to simulate rail weld irregularities mainly focuses on the maximum value and neglects the geometric *** this study,novel theoretical models were developed for three categories of rail weld irregularities,based on measurements of the high-speed railway from Beijing to *** vertical dynamic forces in the time and frequency domains were compared under different running *** forces generated by the rail weld irregularities that were measured and modeled,respectively,were compared to validate the accuracy of the proposed ***,based on the numerical study,the impact force due to rail weld irrregularity is modeled using an Artificial Neural Network(ANN),and the optimum combination of parameters for this model is *** results showed that the proposed model provided a more accurate wheel/rail dynamic evaluation caused by rail weld irregularities than that established in the *** ANN model used in this paper can effectively predict the impact force due to rail weld irrregularity while reducing the computation time.

关键词： Rail weld irregularity high-speed railway vehicle-track coupled dynamics wheel/rail dynamic vertical force artificial neural networks

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Effects of carbon content on the microstructure and tensile properties of a low-density steel

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 391-401页

作者： Yongxuan Shang Mingyu Fan Shuyong Jiang Zhongwu Zhang Key Laboratory of Superlight Materials and Surface technology Ministry of EducationCollege of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001China State Key Laboratory of Metal Material for Marine equipment and Application Iron&Steel Research Institute of Ansteel Group CorporationAnshan 114009China

Carbon can change the phase components of low-density steels and influence the mechanical *** this study,a new method to control the carbon content and avoid the formation ofδ-ferrite by decarburization treatment was *** microstructural changes and mechanical characteristics with carbon content induced by decarburization were systematically ***-Jaoul(C-J)analysis was employed to examine the work hardening characteristics during the tensile *** decarburization by heat treatments,the carbon content within the austenite phase decreased,while Mn and Al were almost unchanged;this made the steel with full austenite transform into the austenite and ferrite dual ***,(Ti,V)C carbides existed in both matrix phase and the mole fraction almost the *** addition,the formation of other carbides *** loss induced a decrease in strength due to the weakening of the carbon solid *** the steel with the single austinite,the deformation mode of austenite was the dislocation planar glide,resulting in the formation of *** the dual-phase steel,the deformation occurred by the dislocation planar glide of austenite first,with the increase in strain,the cross slip of ferrite took place,forming dislocation cells in *** the late stage of deformation,the work hardening of austinite increased rapidly,while that of ferrite increased slightly.

关键词： low-density steels carbon content decarburization strengthening mechanisms work hardening behavior

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Single-order soft x-ray spectra with spectroscopic photon sieve

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Chinese Physics B 2020年第5期29卷 225-228页

作者： Yu-Lin Gao Lai Wei Qiang-Qiang Zhang Zu-Zua Yang Wei-Min Zhou Lei-Feng Cao hi-tech Research and Development Centre China Academy of Engineering PhysicsBeijing 100094China china jiuyuan hi-tech equipment corporation limited Beijing 100094China National Key Laboratory for Laser Fusion Research Center of Laser FusionMianyang 621900China

A single-order diffraction transmission grating named spectroscopic photon sieve(SPS)for soft x-ray region is proposed and demonstrated in this *** SPS consists of many circular pinholes located randomly,and can realize both free-standing diffractions and the suppression of higher-order *** this paper,the basic concept,numerical simulations,and calibration results of a 1000-lines/mm SPS for soft x-ray synchrotron radiation are *** predicted by theoretical calculations,the calibration results of a 1000-lines/mm SPS verify that the higher-order diffractions can be significantly suppressed along the symmetry *** the current nanofabrication technique,the SPS can potentially have a higher line density,and can be widely used in synchrotron radiation,laser-induced plasma diagnostics,and astrophysics.

关键词： higher-order diffraction suppression extreme ultraviolet and soft x-rays single-order diffraction grating

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Key technologies and Applications of the Design and Manufacturing of Non-Circular TBMs

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Engineering 2017年第6期3卷 905-914页

作者： Jianbin Li china Railway hi-tech Industry corporation limited Beijing 100070 China

With the rapid development of the exploitation of underground space, more and more large- or super- large-diameter tunnel-boring machines （TBMs） are being employed to construct underground space projects. At present, because conventional circular TBMs cannot completely meet the requirements of underground space exploitation regarding the cross-section and space-utilization ratio, non-circular TBMs. which are the tunneling equipment for an ideal cross-section, have become the new market growth point. This paper first presents the technical features and development status of non-circular TBMs. Next, in reference to typical projects and technological innovation, this paper investigates key techniques including shield design optimization, multi-cutterhead excavation, special-shaped segment erection, and soil conditioning in loess strata for a rectangular pipe-jacking machine and a horseshoe-shaped TBM, in order to provide a set of feasible solutions for the design, manufacture, and construction of non-circular TBMs. Relevant engineering practice shows that non-circular TBMs with customized design and manufacture have great advantages in terms of construction schedule, settlement control, and space utilization.

关键词： Non-circular TBMs Rectangular pipe-jacking machine Horseshoe-shaped TBM Underground space exploitation

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Preparation and characterization of a new magnetic fluid with good low temperature resistance

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Nano Research 2025年第1期18卷 477-486页

作者： Shilin Nie Decai Li ✉1 Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China State Key Laboratory of Tribology in advanced equipment Tsinghua UniversityBeijing 100084China

Magnetic fluids are a type of novel functionalmaterial that has emerged over the past two decades, whichhave found applications in various aspects of production anddaily life. However, the application of conventional magneticfluids in low-temperature environments is severely limited andoften unsatisfactory. To address this issue, we havedeveloped a new magnetic fluid with excellent low-temperatureresistance. Initially, bare Fe_(3)O_(4) magnetic nanoparticles(FMNPs) were synthesized via co-precipitation without aprotective gas. Subsequently, these particles were modified using polyethylene glycol (PEG)-4000 as a surfactant. Thebare and modified FMNPs (MFMNPs) were characterized using X-ray diffraction (XRD), vibrating sample magnetometer(VSM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetricanalysis-differential thermal gravimetric (TGA-DTG) analysis. The rheological properties, low-temperature resistance of themagnetic fluid were also evaluated. The characterization results indicate that the MFMNPs are spherical andmonodisperse, with a narrow size distribution and a mean particle size of approximately 12 nm. Furthermore, the FTIRspectra and TGA-DTA results suggest that PEG-4000 is linked to the bare Fe_(3)O_(4) particles via hydrogen bonding, indicatingsuccessful modification of the Fe_(3)O_(4) magnetic nanoparticles using PEG. VSM measurements demonstrate that surfacemodification does not alter the crystal morphology or superparamagnetic of Fe_(3)O_(4). However, it does reduce the saturationmagnetization from 68.17 to 54.75 emu/g. Additionally, the prepared magnetic fluid exhibits shear thinning and magneticviscosity effects. It also exhibits excellent low-temperature resistance, maintaining good fluidity without freezing even at -60 ℃. In summary, these results collectively indicate that the new low-temperature resistant magnetic fluid developed in thisstudy is stable and has broad application prospects.

关键词： magnetic fluid low-temperature resistance polyethylene glycol ethylene glycol aqueous solution superparamagnetic

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Development of Novel Hybrid Hand Formed by a Parallel Wrist and Three Soft-flexible Fingers

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Journal of Bionic Engineering 2022年第5期19卷 1349-1358页

作者： Yi Lu Zefeng Chang Yang Lu College of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China Harbin Electric corporation(Qinhuangdao)Heavy equipment Company limited Qinhuangdao 066004China

A prototype of a novel hybrid hand is developed by combing a parallel wrist with three flexible *** dynamics model is established,its grabbed forces are measured,and its grabbing performances are ***,Jacobian and Hessian matrices of the moving platform in the parallel wrist are derived,the kinematics formulas for solving the general velocity and the general acceleration of the moving platform are *** its dynamics model is established for solving the dynamic actuation forces,the dynamic constrained forces of the developed hybrid ***,its simulation mechanism is constructed in Matlab,and the theoretical solutions of the kinematics and the dynamics of the developed hybrid hand are verified to be correct using its simulation ***,when objects with different mass are grabbed by prototype of hybrid hand in different poses,the grabbed forces are measured,and the grabbing performances are discovered and analyzed to verify its merits.

关键词： Hybrid hand Flexible finger mechanism Dynamics Parallel wrist Grabbing performance

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System and prospects of china＇s intercity rail transit technology

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Frontiers of Mechanical Engineering 2018年第2期13卷 323-328页

作者： Ming GONG CRRC corporation limited Beijing 100060 China

City clusters and metropolitan areas in china are flourishing in the midst of the deepening urbanization in the country, thereby resulting in the emergence of intercity rail transit. Intereity railways connect mainline and urban railways for an integrated regional transportation system that underpins and leads the development of city clusters and metropolitan areas. This study explores the development mode and service characteristics of intercity rail transit, as well as proposes overviews on this system and prospects of its future technology in china.

关键词： intercity rail transit city cluster technical demand technology system

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Remaining lifetime prediction for nonlinear degradation device with random effect

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Journal of Systems Engineering and Electronics 2018年第5期29卷 1101-1110页

作者： CAI Zhongyi CHEN Yunxiang GUO Jiansheng ZHANG Qiang XIANG Huachun equipment Management and Unmanned Aerial Vehicle Engineering College Air Force Engineering University Defense technology Academy China Aerospace Science and Industry Corporation Limited

For the large number of nonlinear degradation devices existing in a project, the existing methods have not systematically studied the effects of random effect on the remaining lifetime(RL),the accuracy and efficiency of the parameters estimation are not high, and the current degradation state of the target device is not accurately estimated. In this paper, a nonlinear Wiener degradation model with random effect is proposed and the corresponding probability density function(PDF) of the first hitting time(FHT)is deduced. A parameter estimation method based on modified expectation maximum(EM) algorithm is proposed to obtain the estimated value of fixed coefficient and the priori value of random coefficient in the model. The posterior value of the random coefficient and the current degradation state of target device are updated synchronously by the state space model(SSM) and the Kalman filter algorithm. The PDF of RL with random effect is deduced. A simulation example is analyzed to verify that the proposed method has the obvious advantage over the existing methods in parameter estimation error and RL prediction accuracy.

关键词： remaining lifetime(RL) prediction nonlinear degradation model Wiener process random coefficient Kalman filter algorithm

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Near-Zero Air Pollutant Emission technologies and Applications for Clean Coal-Fired Power

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Engineering 2020年第12期6卷 1408-1422页

作者： Shumin Wang china Energy Investment corporation limited Beijing 100011China

Coal is the dominant energy source in china,and coal-fired power accounts for about half of coal ***,air pollutant emissions from coal-fired power plants cause severe ecological and environmental *** paper focuses on near-zero emission technologies and applications for clean coal-fired *** long-term operation states of near-zero emission units were evaluated,and synergistic and special mercury(Hg)control technologies were *** results show that the principle technical route of near-zero emission,which was applied to 101 of china’s coal-fired units,has good adaptability to coal *** emission concentrations of particulate matter(PM),SO2,and NOx were below the emission limits of gas-fired power plants and the compliance rates of the hourly average emission concentrations reaching near-zero emission in long-term operation exceeded 99%.With the application of near-zero emission technologies,the generating costs increased by about 0.01 CNY∙(kW∙h)-***,the total emissions of air pollutants decreased by about 90%,resulting in effective improvement of the ambient air ***,while the Hg emission concentrations of the near-zero emission units ranged from 0.51 to 2.89μg∙m^-3,after the modified fly ash(MFA)special Hg removal system was applied,Hg emission concentration reached as low as 0.29μg∙m^-*** operating cost of this system was only 10%-15%of the cost of mainstream Hg removal technology using activated carbon *** on experimental studies carried out in a 50000 m^3∙h^-1 coal-fired flue gas pollutant control pilot platform,the interaction relationships of multi-pollutant removal were obtained and solutions were developed for emissions reaching different limits.A combined demonstration application for clean coal-fired power,with the new“1123”eco-friendly emission limits of 1,10,20 mg∙m^-3,and 3μg∙m^-3,respectively,for PM,SO2,NOx,and Hg from near-zero emission coal-fired power were put forward

关键词： Clean coal-fired power Air pollutants Near-zero emission Pilot platform New“1123”eco-friendly emission limits

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Fabrication and characterization of AleCuO nanocomposites prepared by sol-gel method

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Defence technology（防务技术） 2021年第4期17卷 1307-1312页

作者： Yue-ting Wang Xiao-ting Zhang Jian-bing Xu Yun Shen Cheng-ai Wang Fu-wei Li Ze-hua Zhang Jian Chen Ying-hua Ye Rui-qi Shen Department of Applied Chemistry School of Chemical EngineeringNanjing University of Science and TechnologyNanjing210094China Anhui Xinhe Defense equipment technology corporation limited Anhui230000China

In this study,AleCuO nanocomposites were fabricated by sol-gel *** a contrast,the thermite was prepared by physical mixing at the equivalence ratio of 0.5,1,2,*** intermediates and samples as prepared were characterized by SEM and *** exothermic properties of the two samples prepared at different equivalence ratios were tested and the reaction products were characterized by *** SEM results show that the sample prepared by the sol-gel method demonstrates a micron-sized agglomerated sphere formed by a mutual wrapping of Al NPs and CuO NPs,and the particles are evenly distributed in the *** addition,when the content of Al powder is seriously insufficient,the heat release of the sample prepared by physical mixing is 1.6 times that of by sol-gel *** the increase of Al powder content,the exothermic properties of Al/CuO NPs prepared by sol-gel method began to increase significantly compared with physical mixing and the difference is 1.5 times when the equivalence ratio increases to *** can be concluded that the reason for this result may be attributed to the different mass transfer modes of components due to the different morphologies of samples.

关键词： Nanothermite Energetic materials Sol-gel Characterization

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