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SSRN 2024年

作者： Liu, Moukai Han, Jian Wenxu, Han Wu, Qirui Xiao, Xinbiao State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong University Sichuan Chengdu610031 China School of Mechanical Engineering Southwest Jiaotong University Sichuan Chengdu610031 China

This study focuses on the acoustic comfort evaluation of high-speed train operating in tunnels based on electroencephalogram (EEG) signals. Field tests were conducted on a specific high-speed train at various speeds and different measurement points to collect interior noise data as the acoustic samples. These acoustic samples were then used for EEG tests on individuals, to capture participants' EEG responses. Following preprocessing and denoising of the EEG signals, features such as the power of different rhythms and sample entropy were extracted. The study analyzed the correlation between EEG features and psychological acoustic annoyance, the adopted indicator of acoustic comfort, and performed time-frequency characteristic analysis to observe the changes in EEG signals in different operating environments (Open lines and tunnels). © 2024, The Authors. All rights reserved.

关键词： Electroencephalography

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Free-form surface texture morphology evaluation for tool posture range constraint-based texture quality control in five-axis ball-end milling

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Journal of Manufacturing Processes 2025年 149卷 1046-1065页

作者： Guoqiang Fu Sipei Zhu Yue Zheng Caijiang Lu Xi Wang Tao Wang Jianzhong Fu School of mechanical engineering Southwest Jiaotong University Chengdu 610031 China State Key Laboratory of Precision Manufacturing for Extreme Service Performance Central South University Changsha 410083 China The Intelligent Manufacturing Longcheng Laboratory Changzhou 213000 China Technology and Equipment of Rail Transit Operation and Maintenance Key Laboratory of Sichuan Province Chengdu 610031 China State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang University Hangzhou 310027 China

The quality of free-form surface texture morphology machined by five-axis ball-end milling directly affects the mechanical and physical properties of the industrial parts. While, the precision assurance strategies in five-axis milling, such as path optimization, singularity avoidance, and error compensation, may affect the free-form texture quality, especially texture overall trends. In this paper, free-form surface overall texture morphology evaluation in five-axis ball-end milling is proposed to obtain the classification of texture morphology and corresponding tool posture angle range. The texture quality control is achieved through adjusting tool postures in the tool posture angle range of each class texture. Firstly, free-form surface texture morphology digital model is proposed based on the texture generation mechanism in five-axis ball-end milling. Secondly, free-form surface texture evaluation is proposed, including overall texture evaluation indexes, texture morphology classification and tool posture angle range determination. The evaluation indexes of texture distribution, clarity and similarity are obtained based on the gray image matrix of the texture morphology. The contour line is extracted to reflect the trend of the overall texture morphology. Evaluation indexes-based classification method is proposed to obtain the preliminary classification of texture morphology. Further, PCA-SCC-KM-based classification method is proposed using height residual value of the machined free-form surface to obtain the detailed classification of texture morphology. Tool posture dichotomy-based range determination method is proposed to obtain the continuous tool posture angle range of each texture class. The texture morphology digital model of bowl-shaped free-form surface is established as the example for the evaluation. The texture morphology is primarily divided into complex texture with small inclination angle and regular texture with large inclination angle. Further, t

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Analytical Solution of Mechanical Response in Large Diameter Ring Structure Considering Shear Effect

Analytical Solution of Mechanical Response in Large Diameter...

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2024 International Conference on Construction and Real Estate Management: ESG Development in the Construction Industry, ICCREM 2024

作者： Zeng, Yi Zhang, Yanlong Chen, Fubin Lu, Andian Yelv, Gendi Xiong, Wang Wu, Ze Li, Xiaoping Fu, Yanbin Guo, Yuehua Liao, Longhui Zhu, Junzhou Shanghai Tunnel Engineering & Rail Transit Design and Research Institute Shanghai China Guangdong Provincial Key Laboratory of Tunnel Safety and Emergency Support Technology & Equipment Guangzhou China Guangdong Hualu Transport Technology Co. Ltd. Guangzhou China Shenzhen Traffic Engineering Quality Supervision Station Guangdong Shenzhen China Guangdong GDH Pearl River Delta Water Supply Co. Ltd. Guangdong Guangzhou China Sinohydro Bureau 14 Co. Ltd. Guangdong Shenzhen China Urban Rail Transit Design and Research Institute China Railway Engineering Design and Consulting Group Co Ltd. Beijing China State Key Laboratory of Intelligent Geotechnics and Tunnelling College of Civil and Transportation Engineering Shenzhen Univ. Guangdong Shenzhen China CCCC-FHEC Ecological Engineering Co. Ltd. China College of Civil and Transportation Engineering Shenzhen Univ. Guangdong Shenzhen China

ISBN: (数字)9780784485910

ISBN: (纸本)9780784485910

The adjacent engineering construction will cause the underground structure not only the bending deformation but also the shear deformation. Focusing on the shear deformation after the deflection of the circumferential section, ring structure is assumed to be homogeneous isotropic elastic, and a series of analytical solutions of bending stress, shear stress, shear force, axial force, and bending moment of the ring structure under the concentrated load are derived. The analytical solution of the ring structure is verified by the monitored data of the engineering case that the pile foundation pressed the tunnel structure. Taking the Chunfeng Tunnel as an example for parameter analysis shows that the ring structure has a significant shear effect under the action of concentrated load. The shear force increment of the ring structure is greater when it is closer to the load point. The analytical solution in this paper can provide a theoretical basis for the calculation and performance evaluation of ring structures such as tunnels. © ASCE.

关键词： Piles

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A Non-Nearest Space Vector Modulation with Reduced Common-Mode Voltage for Three-Level ANPC Inverter Fed PMSM Drives

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IEEE Journal of Emerging and Selected Topics in Power Electronics 2025年

作者： Ren, Guanzhou Ma, Guangtong Yao, Chunxing Xu, Shuai Southwest Jiaotong University State Key Laboratory of Rail Transit Vehicle System Chengdu 610031 China Southwest Jiaotong University School of Electrical Engineering Chengdu 610031 China

Due to the advantages of low harmonic distortion, low voltage stress and high efficiency, three-level inverters have been widely employed in various applications. Conventional three-level PWM methods typically adjust the duty ratio of redundant small vectors to achieve NP voltage control. Conversely, CMV reduction methods avoid using redundant small vectors that generate high common mode voltage. To address this issue, this paper proposes a novel modulation technique for three-level inverters. This approach is developed based on the non-nearest space vector synthesis criterion, reducing the CMV amplitude to 50% compared to conventional SVPWM. Furthermore, a new NP voltage balance method is proposed, which utilizes small and medium vectors with opposite neutral-point currents to adjust the neutral-point voltage. The performance of this modulation approach is validated by comparative simulations and experimental tests, with the results presenting lower total harmonic distortion, improved NP voltage regulation capability, and enhanced inverter efficiency. © 2013 IEEE.

关键词： Common-mode voltage neutral-point voltage non-nearest space vector pulse width modulation three-level inverter

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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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International Conference on Applied Superconductivity and Electromagnetic Devices, ASEMD

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

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.

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Energy-Efficient Operation of Train Platoons in Urban rail transit Systems:An MIP Approach

Energy-Efficient Operation of Train Platoons in Urban Rail T...

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第43届中国控制会议

作者： Haodong Li Jiateng Yin Tao Tang Andrea D'Ariano Mengxing You State Key Laboratory of Advanced Rail Autonomous Operation Beijing Jiaotong University School of Systems Science Beijing Jiaotong University Department of Civi Computer Science and Aeronautical Technologies Engineering Nanchang Rail Transit Group Co. Ltd.

ISBN: (数字)9789887581581

ISBN: (纸本)9798350366907

Train platooning,which allows multiple train units to be virtually coupled into a platoon with very short following distances,has become an emerging technology in railway *** study investigates the energy-efficient operation of train platoons to reduce the energy consumption of trains while satisfying time-varying passenger demands in *** develop a mixed integer programming(MIP) model to optimize the timetable,running speed and coupling strategies of *** that the small-size train platoons consume much less energy but can serve fewer passengers,our model involves bi-objectives,i.e.,to minimize the passenger waiting time and to minimize the overall energy consumption of *** also construct a series of model constraints to limit the movement of trains as well as the time-dependent flows of passengers,since a part of passengers during the peak period may have to wait for a longer time due to the capacity limitation of different sizes of ***,we conduct real-world case studies on the Beijing subway Yizhuang line to verify the effectiveness of our *** results indicate that the energy-efficient operation of train platoons can achieve a better trade-off between service quality and system energy consumption.

关键词： Flexible coupling Mixed-integer linear programming Energy savings Passenger flow

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Sealing Evaluation of Helium Storage in Salt Caverns Leached from Bedded Rock Salt: A Case Study in China

SSRN

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SSRN 2024年

作者： Chen, Xiangsheng Xiong, Tiankai Li, Yinping State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure East China Jiaotong University Jiangxi Nanchang330013 China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Hubei Wuhan430071 China

To improve the safety and scale of helium storage, large-scale or strategic helium storage in underground salt caverns can be implemented. Salt caverns leached from bedded salt formations have been considered as potential underground storage sites for helium in China. However, the salt formations are typical lacustrine sedimentary rocks with an interbedded structure, thus the sealing feasibility of such salt caverns must be evaluated before they can be used. To this end, the helium seepage equation in deep formations and permeability evolution function are derived with the help of experimental results and theoretical analysis. Based on these, a helium seepage model considering slippage effect and threshold pressure gradient is proposed to evaluate the sealing properties of salt caverns for helium storage. The analysis results indicate that it is feasible to use bedded salt mine formations for helium storage when the formations permeability parameters and reservoir design parameters meet the long-term tightness evaluation criteria, including permeability, porosity, salt pillar width, salt roof thickness and operating pressure and duration. More importantly, specific recommendations are provided for the operation parameters, design parameters and formation permeability thresholds of salt caverns for ensuring helium storage safety while maintaining stable cavern operations. The threshold permeability of the target salt formations should be approximately 1×10-18 m2 to ensure tightness. The minimum and maximum operating pressure are recommended to be 10 MPa and 18 MPa respectively for 50 years of this helium storage. The salt pillar width should be 300 m, and the salt roof thickness should be 40 m. © 2024, The Authors. All rights reserved.

关键词： Roofs

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Mwd-based real-time identification of rock weathering: A comparison of supervised and unsupervised machine learning methods

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Tunnelling and Underground Space Technology 2025年 163卷

作者： Li, Yang Chen, Jiayao Shen, Yifan Fang, Qian Man, Jianhong Key Laboratory for Urban Underground Engineering of Ministry of Education and School of Civil Engineering Beijing Jiaotong University Beijing100044 China State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure East China Jiaotong University China State Key Laboratory of Geomechanics and Geotechnical Engineering Safety Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan China Beijing Key Laboratory of Urban Underground Space Engineering University of Science and Technology Beijing No. 30 Xueyuan Road Haidian District Beijing100083 China

A large-scale database linking six-dimensional tunneling parameters to rock weathering conditions was constructed from measurement-while-drilling (MWD) data during tunnel construction utilizing the drill-and-blast method. A data-driven predictive model was developed, integrating random search (RS) with a random forest (RF) classifier, for efficient, real-time identification of unexcavated rock weathering levels. Nine comparative models combining CART and XGBoost with hyperparameter optimization were also evaluated using the Macro F1 score. The classification performance, applicability, and generalization capabilities of the proposed model were analyzed. Additionally, several unsupervised models were employed for clustering analysis, leveraging inherent data characteristics. Results demonstrated that the RS-RF algorithm outperforms other models in identifying rock weathering levels, with rotation pressure as the primary classification feature. For large, highly similar datasets, supervised algorithms exhibited superiority over their unsupervised counterparts. Consequently, the proposed model enables optimal classification of rock weathering conditions, thereby providing essential information for subsequent support and measurement. © 2025 Elsevier Ltd

关键词： Unsupervised learning

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The knowledge modeling of bridge code for automated completeness checking

The knowledge modeling of bridge code for automated complete...

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International Conference on Computational Intelligence and Security

作者： Yang Xiao Zongjian Li Qin Zhao Yaqin Chen Hao Li School of Civil Engineering and Architecture Xi'an University of Technology Xi'an China State Key Laboratory of Rail Transit Engineering Informatization (FSDI) China Railway First Survey and Design Institute Group Ltd Xi'an China

Completeness checking of BrIM(Bridge Information Model) plays a critical role in identifying missing information according to standard documents and ensuring the depth of the designs. However, the method of traditional checking relies heavily on human work. To achieve automated completeness checking for BrIM, we propose a knowledge model construction method to solve the problem of standard specifications interpretation. Firstly, we expand the domain of the knowledge ontology based on Semantic Web technology, extract and integrate the collection of domain terms, define classes and property relationships in the ontology, and build the domain knowledge ontology. And then, we preprocess provisions to obtain single semantic rule sentences following the text characteristics of the Chinese delivery standard and construct multi-level logical expressions according to their different knowledge types. Finally, we build the domain knowledge model consisting of an ontology and logical expressions that can be used in the completeness checking of $\mathbf{BrIM}$ to describe the knowledge of codes and standards in the bridge design domain at a fine-grained level. The knowledge model improves the effectiveness and efficiency of the translation process and offers technical support for intelligent completeness checking.

关键词： Bridges Knowledge engineering Semantic Web Codes railway engineering Computational modeling Semantics

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A study on the fretting wear characteristic of Inconcel 718 alloys formed by selective laser melting(SLM)

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Wear 2025年 571卷

作者： Xu, Zhi-biao Lu, Hao-wen Zeng, Xin-yi Wang, Xiao-yi Wu, Hao Peng, Jin-fang Zhu, Min-hao College of Intelligent Manufacturing Guangzhou Maritime University Guangzhou510725 China School of Rail Transportation Wuyi University Jiangmen529020 China Guangdong Key Laboratory of Materials and Equipment in Harsh Marine Environment School of Naval Architecture and Ocean Engineering Guangzhou Maritime University Guangzhou510725 China State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong University Chengdu 610031 China Shandong Key Laboratory of Advanced Aluminum Materials and Technology Binzhou256606 China

The selective laser melting (SLM) technology has plays pivotal role in aerospace equipment, medical instrument, mold manufacturing and nuclear power industries due to its ability to rapidly fabricate intricate parts in recent *** methods like casting and forging often lead to Inconel 718 alloy parts with issues such as element segregation, coarse grain and structural simplicity. All such shortcomings are overcome by SLM technology, it's enabling to production Inconel 718 alloy parts with complex, fine grained and high density. Given the increasing reliance on SLM for creating Inconel 718 alloys, there is growing interest in the operational characteristics of these materials, including their mechanical, fatigue, and fretting wear properties. This study explores the fretting wear properties of Inconel 718 alloy produced by SLM, using an in-house designed fretting wear tester under various normal loads and displacement amplitudes. The coefficient of friction (COF) curve and friction force displacement (Ft-D) data during the fretting wear process were analyzed for a detailed dynamic responds. Additionally, the fretting wear damage and cross-section morphology were examined using a scanning electron microscope (SEM) and a three-dimensional profilometer (3D).The results show that the COF curve and Ft-D curve during the fretting wear process are greatly affected by the displacement amplitude and normal load. With the increase of normal load or the decrease of displacement amplitude, the fretting running state changes from the gross slip regime (GSR) to the mixed slip regime (MSR) and finally to the partial slip regime (PSR), and the most serious material damage occurs when the fretting state runs in the MSR. During the shift from the PSR to the MSR and the GSR, the fretting wear mechanism evolves from predominantly adhesive wear and abrasive wear to a dominance of fatigue wear and material delamination. The fretting wear damage of the material is influenced b

关键词： Fatigue damage

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