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3rd International Conference on rail Transportation, ICRT 2024

作者： Zhou, Ziwei Ye, Zirui Chen, Zaigang State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong Univ. Chengdu China Faculty of Transportation Engineering Kunming Univ. of Science and Technology Kunming China

ISBN: (数字)9780784485941

ISBN: (纸本)9780784485941

This paper investigates the dynamics and wear characteristics of bearings in a locomotive's traction transmission system, emphasizing the electromechanical coupling effects. A comprehensive locomotive-track coupled dynamics model, integrating electrical and mechanical subsystems, is utilized to simulate the behavior under typical operational conditions without considering track irregularities. The study introduces a wear model based on Archard's theory, applied to cylindrical roller bearings, which quantifies wear evolution via dynamic contact parameters and stress distributions. Simulations at 80 km/h reveal significant wear differences between models with and without electromechanical coupling, underscoring the impact of such coupling on bearing durability and locomotive performance. The findings illustrate that electromechanical interactions exacerbate wear, particularly on the driving end, and suggest that incorporating these factors can lead to more accurate predictions of bearing lifespan and maintenance scheduling. © ASCE.

关键词： Roller bearings

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Fracture distribution in overburden strata induced by underground mining

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Deep Underground Science and engineering 2022年第1期1卷 58-64页

作者： Wenli Yao Enzhi Wang Xiaoli Liu Ran Zhou Department of Hydraulic Engineering State Key Laboratory of Hydroscience and EngineeringTsinghua UniversityBeijingChina Department of Hydraulic Engineering YSD Rail Transit Construction Company LimitedGuangzhouChina

Coal-mining activities give rise to a series of ecological environmental problems,such as ground settlement and groundwater *** fact,they are mainly caused by mining-induced ***,it is necessary to study the mining-induced fracture distribution to identify the behavior of rock mass ***,the fractures in overburden strata cannot be directly measured owing to the special ***,the majority of previous studies are based on experiments or *** this reason,this study first used a discrete element method to simulate the shape of mining-induced fractures in overburden ***,a geophysical tool of transient electromagnetic method(TEM)was used to investigate the mining-induced fracture *** on the low-resistivity anomaly area,the water-rich area in overburden strata was analyzed to be mainly caused by fracture *** the mutual authentication between numerical simulation and TEM results,the mining-induced fractures in overburden strata were *** study can enhance the understanding of mining-induced fracture distribution on the one hand and guarantee the coal mining safety on the other,thus guiding the coordinated development between coal mining and environmental protection.

关键词： groundwater seepage mining-induced fracture numerical simulation rock mass deformation TEM

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Identification of failure behaviors of underground structures under dynamic loading using machine learning

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Journal of Rock Mechanics and Geotechnical engineering 2025年第1期17卷 414-431页

作者： Chun Zhu Yingze Xu Manchao He Yujing Jiang Murat Karakus Lihua Hu Yalong Jiang Fuqiang Ren School of Earth Sciences and Engineering Hohai UniversityNanjing210098China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing400044China State Key Laboratory for Geomechanics&Deep Underground Engineering Xuzhou221116China Graduate School of Engineering Nagasaki UniversityBunkyoNagasaki852-8521Japan School of Civil Environmental and Mining EngineeringThe University of AdelaideAdelaide5005SAAustralia State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure East China Jiaotong UniversityNanchang330013China School of Civil Engineering University of Science and Technology LiaoningAnshan114051China

Understanding the dynamic responses of hard rocks is crucial during deep mining and tunneling activities and when constructing nuclear waste repositories. However, the response of deep massive rocks with openings of different shapes and orientations to dynamic loading is not well understood. Therefore, this study investigates the dynamic responses of hard rocks of deep underground excavation activities. Split Hopkins Pressure Bar (SHPB) tests on granite with holes of different shapes (rectangle, circle, vertical ellipse (elliptical short (ES) axis parallel to the impact load direction), and horizontal ellipse (elliptical long (EL) axis parallel to the impact load direction)) were carried out. The influence of hole shape and location on the dynamic responses was analyzed to reveal the rocks' dynamic strengths and cracking characteristics. We used the ResNet18 (convolutional neural network-based) network to recognize crack types using high-speed photographs. Moreover, a prediction model for the stress-strain response of rocks with different openings was established using Deep Neural Network (DNN). The results show that the dynamic strengths of the granite with EL and ES holes are the highest and lowest, respectively. The strength-weakening coefficient decreases first and then increases with an increase of thickness-span ratio (h/L). The weakening of the granite with ES holes is the most obvious. The ResNet18 network can improve the analyzing efficiency of the cracking mechanism, and the trained model's recognition accuracy reaches 99%. Finally, the dynamic stress-strain prediction model can predict the complete stress-strain curve well, with an accuracy above 85%.

关键词： Dynamic mechanical response Cracking mode Hole shape/location effect Deep Neural Network(DNN) Stress-strain prediction

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Adaptive fast sliding mode control method for induction motors

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Kongzhi yu Juece/Control and Decision 2025年第6期40卷 1866-1872页

作者： Ji, Juan-Juan Cui, Yan-Liang Wang, Kai-Yun School of Mechanical and Electrical Engineering Lanzhou Jiaotong University Lanzhou730070 China State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong University Chengdu610031 China

This paper proposes an adaptive non-singular fast terminal sliding mode control(NFTSMC) method that effectively enhances the speed control performance of induction motors under external disturbances and parameter variations. First, an adaptive nonlinear control method is introduced that improves the system's disturbance rejection capability and dynamic response performance while suppressing chattering in sliding mode control. Then, the proposed sliding mode load torque observer(SMLTO) ensures rapid and accurate tracking of the actual torque during load torque fluctuations, reducing speed fluctuations caused by sudden changes in load torque and improving control precision and robustness. Furthermore, the non-singular terminal sliding mode control approach accelerates the system’s state convergence rate and avoids the singularity issues encountered in traditional sliding mode control. Experimental results demonstrate that the proposed method significantly enhances the robustness and response speed of the induction motor speed control system, while showing excellent load torque observation performance. © 2025 Northeast University. All rights reserved.

关键词： Sliding mode control

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Advancing high-speed train gearbox durability:enhanced bearing load and contact stress through transition from helical to herringbone gears

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railway engineering Science 2024年第4期32卷 461-479页

作者： Hao Wu Jing Wei Pingbo Wu Fansong Li Yayun Qi School of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China College of Mechanical and Vehicle Engineering Chongqing UniversityChongqing 400044China State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610034China School of Mechanotronics and Vehicle Engineering Chongqing Jiaotong UniversityChongqing 400074China

High-speed trains typically utilize helical gear transmissions,which significantly impact the bearing load capacity and fatigue service performance of the gearbox *** paper focuses on the gearbox bearings,establishing dynamic models for both helical gear and herringbone gear transmissions in high-speed *** modeling particularly emphasizes the precision of the bearings at the gearbox's pinion and gear *** this model,a comparative analysis is conducted on the bearing loads and contact stresses of the gearbox bearings under uniform-speed operation between the two gear *** findings reveal that the helical gear transmission generates axial forces leading to severe load imbalance on the bearings at both sides of the large gear,and this imbalance intensifies with the increase in train ***,this results in a significant increase in contact stress on the bearings on one *** adoption of herringbone gear transmission effectively suppresses axial forces,resolving the load imbalance issue and substantially reducing the contact stress on the originally biased side of the *** study demonstrates that employing herringbone gear transmission can significantly enhance the service performance of high-speed train gearbox bearings,thereby extending their service life.

关键词： High-speed train Herringbone gear Helical gear Gearbox bearings Contact stress

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Super-resolution reconstruction of single image for latent features

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Computational Visual Media 2024年第6期10卷 1219-1239页

作者： Xin Wang Jing-Ke Yan Jing-Ye Cai Jian-Hua Deng Qin Qin Yao Cheng School of Information and Software Engineering University of Electronic Science and Technology of ChinaChengdu 610000 China State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610000China School of Marine Engineering Guilin University of Electronic TechnologyGuilin 541000China School of Computer and Information Security Guilin University of Electronic TechnologyGuilin 541000China

Single-image super-resolution(SISR)typically focuses on restoring various degraded low-resolution(LR)images to a single high-resolution(HR)***,during SISR tasks,it is often challenging for models to simultaneously maintain high quality and rapid sampling while preserving diversity in details and texture *** challenge can lead to issues such as model collapse,lack of rich details and texture features in the reconstructed HR images,and excessive time consumption for model *** address these problems,this paper proposes a Latent Feature-oriented Diffusion Probability Model(LDDPM).First,we designed a conditional encoder capable of effectively encoding LR images,reducing the solution space for model image reconstruction and thereby improving the quality of the reconstructed *** then employed a normalized flow and multimodal adversarial training,learning from complex multimodal distributions,to model the denoising *** so boosts the generative modeling capabilities within a minimal number of sampling *** comparisons of our proposed model with existing SISR methods on mainstream datasets demonstrate that our model reconstructs more realistic HR images and achieves better performance on multiple evaluation metrics,providing a fresh perspective for tackling SISR tasks.

关键词： image superresolution reconstruction denoising diffusion probabilistic model normalized flow adversarial neural network variational auto-encoder

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Quench behaviors of parallel-wound no-insulation high temperature superconductor coils

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Superconductivity 2024年第4期12卷 134-148页

作者： Yutong Fu Guangtong Ma Fangliang Dong Yawei Wang School of Electronic Information and Electrical Engineering Shanghai Jiao Tong UniversityShanghai200240China School of Electrical Engineering and State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu610031China Francis Bitter Magnet Laboratory/Plasma Science and Fusion Center Massachusetts Institute of TechnologyCambridgeMA 02139USA

No-insulation(NI)high-temperature superconducting(HTS)coil wound with parallel-stacked tapes emerges as a prospective choice for high-field fusion magnets owing to lower inductance and faster ramping *** parallel stacked-tape structure leads to new current redistribution among stacked tapes in each turn during local quenches,which also considerably changes the current redistribution behavior through inter-turn ***,quench behaviors of parallel-wound no-insulation(PWNI)coil should differ from its counterpart wound with single tape,which are still *** study is to illustrate quench behaviors of PWNI HTS coils induced by local hot spot.A multi-physics model integrating an equivalent circuit network,a FEM heat transfer module,and a FEM T-A model is developed to analyze the electromagnetic and thermal characteristics of PWNI HTS coils during *** show that the transport currents are mainly redistributed among parallel-stacked tapes through terminal resistances when a local hot spot happens on one tape,while being less dependent on turn-to-turn electrical *** leads to a coupling current within PWNI coils that is not present in NI coils wound with single tape(single-wound no-insulation(SWNI)coil),resulting in a highly non-uniform transport current distribution among parallel-wound *** reduced terminal joint resistances further enhance the coupling current,potentially leading to an extra overcurrent quench risk in PWNI ***,the current redistribution between parallel-stacked tapes inhibits the turn-to-turn current redistribution in the PWNI coil,thus significantly reducing its magnetic field degradation under a high heat disturbance,which can be almost less than half of the SWNI counterpart in this *** results offer important theoretical guidance to safety operation and robustness improvement of high-field HTS magnets wound by PWNI technique.

关键词： Parallel-wound no-insulation(PWNI)coil Quench behaviors Current redistribution High temperature superconducting(HTS)magnet

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Mechanical properties of steel mesh in anchor-mesh support for rocky tunnels

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Journal of Mountain Science 2024年第10期21卷 3487-3502页

作者： SUN Keguo JIA Jinglong XU Weiping ZHANG Yu WANG Jinjin WANG Yichao LIU Yongkui Key Laboratory of Transportation Tunnel Engineering Ministry of EducationSchool of Civil EngineeringSouthwest Jiaotong UniversityChengdu 610031China State Key Laboratory of Intelligent Geotechnics and Tunnelling Chengdu 610031China Chengdu Rail Transit Group Co. Ltd.Chengdu 610036China China Railway 14th Bureau Group 2nd Engineering Corporation Limited China Railway Construction Corporation LimitedTaian 271000China

Underground geotechnical engineering encounters persistent challenges in ensuring the stability and safety of surrounding rock structures, particularly within rocky tunnels. Rock reinforcement techniques, including the use of steel mesh, are critical to achieving this goal. However, there exists a knowledge gap regarding the comprehensive understanding of the mechanical behavior and failure mechanisms exhibited by steel mesh under diverse loading conditions. This study thoroughly explored the steel mesh's performance throughout the entire loading-failure process, innovating with detailed analysis and modeling techniques. By integrating advanced numerical modeling with laboratory experiments, the study examines the influence of varying reinforcement levels and geometric parameters on the steel mesh strength and deformation characteristics. Sensitivity analysis, employing gray correlation theory, identifies the key factors affecting the mesh performance, while a BP (Backpropagation) neural network model predicts maximum vertical deformation with high accuracy. The findings underscore the critical role of steel diameter and mesh spacing in optimizing peak load capacity, displacement, and energy absorption, offering practical guidelines for design improvements. The use of a Bayesian Regularization (BR) algorithm further enhances the predictive accuracy compared to traditional methods. This research provides new insights into optimizing steel mesh design for underground applications, offering an innovative approach to enhancing structural safety in geotechnical projects.

关键词： Tunnel Steel mesh BP neural network Anchor-mesh support Rock reinforcement technique

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Analysis of Stray Magnetic Field of Superconducting Magnets inside Superconducting Electrodynamic Suspension Carriages

Analysis of Stray Magnetic Field of Superconducting Magnets ...

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2023 IEEE International Conference on Applied Superconductivity and Electromagnetic Devices, ASEMD 2023

作者： He, Shi-Cheng Zheng, Jun Southwest Jiaotong University School of Electrical Engineering Chengdu China Southwest Jiaotong University State Key Laboratory of Rail Transit Vehicle System Chengdu China

ISBN: (纸本)9798350301571

A three-dimensional electromagnetic simulation model of superconducting electrodynamic suspension on-board superconducting magnets, null-flux coils, propulsion coils, and carriage structure is established using finite element simulation. The stray magnetic field inside the carriage is analyzed exhaustively, and the magnetic field distribution in the interior space of the carriage is obtained. The results show that the maximum static magnetic field inside the carriages exceeds 30 mT and the peak low-frequency magnetic field is 6 mT. This is higher than the limit values suggested by the International Commission on Non-Ionizing Radiation Protection for static magnetic field (0.5 mT) and low-frequency (1-100 Hz) magnetic field (0.2 mT). This work can provide a reference value for the optimal design of magnetic shielding for superconducting electric magnetic levitation trains. © 2023 IEEE.

关键词： electrodynamic suspension Magnetic shielding stray magnetic field superconducting magnets

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Optimal Energy-Efficient Operation of a Metro Train on a Long and Steep Downhill Segment

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CSEE Journal of Power and Energy Systems 2023年第6期9卷 2356-2365页

作者： Deqiang He Hanqing Jian Yanjun Chen Jian Miao Zhixiao Luo Chonghui Ren Lang Zhang the department of State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures Guangxi Key Laboratory of Manufacturing System&Advanced Manufacturing TechnologySchool of Mechanical EngineeringGuangxi UniversityNanning 530004China the department of Guangxi Police College Nanning 530028China. the department of Nanning Rail Transit Co. Ltd.Nanning 530029China

Because the standard four-stage operation and con-trol strategy cannot fully utilize the gravitational potential energy of a train operating on a long and steep downhill segment,this paper further improves the method for train operation and control *** improved operation includes three stages of acceleration,coasting-speed limit cruising,and *** the speed limit,time limit,and distance limit as the constraints,the coasting condition switching point,braking condition switching point,traction coefficient,and braking force coefficient are used as the decision ***,an improved train traction energy consumption model is constructed,and an improved differential evolution algorithm is designed to solve this *** improved method is used to simulate two long and steep downhill segments of the Nanning *** results show that the improved method can meet the requirements of speed limit,time limit,and distance *** with the standard four-stage operation,the improved train operation and control strategy can reduce train energy consumption by more than 40%on the two long and steep downhill segments;compared with other similar algorithms,the improved algorithm is more suitable for solving the model.

关键词： Energy-efficient operation improved differential evolution algorithm long and steep downhill segment metro train

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