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Lubrication Failure Mechanism of Rolling‑Sliding Steel Ball Against Oil-Impregnated Porous Polyimide and Bearing Steel in Double Friction Pair

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SSRN 2024年

作者： Yin, Yang Shi, Pengfei Zhang, Shaohua Qing, Tao Zhou, Ningning Qian, Linmao Chen, Lei Tribology Research Institute State Key Laboratory of Rail Transit Vehicle System School of Mechanical Engineering Southwest Jiaotong University Chengdu610031 China Technology and Equipment of Rail Transit Operation and Maintenance Key Laboratory of Sichuan Province School of Mechanical Engineering Southwest Jiaotong University Sichuan Chengdu610031 China Beijing Key Laboratory of Long-life Technology of Precise Rotation and Transmission Mechanisms Beijing Institute of Control Engineering Beijing100094 China

Oil-impregnated porous polyimide (O-PPI) cages play a crucial role in aerospace bearings due to their exceptional performance and self-lubrication characteristics. However, their service life is significantly impacted by surface blackening failure. The intricate interaction among steel balls, cages, and inner/outer rings in bearing complicates the understanding of blackening mechanisms. Our study designed a novel double-contact rolling-sliding ball holder to successfully replicate the blackening phenomenon on the O-PPI surface. Experiment results indicate the iron debris generated from steel-steel friction in the second pair will infiltrate the PPI surface pores, and more importantly, the presence of Fe in iron debris efficiently catalyzes the splitting reaction of the PAO oil at the contact surface during the frictional process, leading to the distinct blackening failure phenomenon. © 2024, The Authors. All rights reserved.

关键词： Polyimides

Deeply Understanding Lubrication Failure of Steel Ball Against Oil-Impregnated Porous Polyimide in Double-Contact Friction with Rolling‑Sliding Motion

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SSRN 2024年

Oil-impregnated porous polyimide (O-PPI) cages play a crucial role in aerospace bearings due to their exceptional performance and self-lubrication characteristics. However, their service life is significantly impacted by surface blackening behavior. The intricate interaction among steel balls, cages, and inner/outer rings in bearing complicates the understanding of blackening mechanisms. Our study designed a novel double-contact rolling-sliding ball holder to successfully replicate the blackening phenomenon on the O-PPI surface. Experiment results indicate the iron debris generated from steel-steel friction in the second pair will infiltrate the PPI surface pores, and more importantly, the presence of Fe in iron debris catalyzes the splitting reaction of the PAO oil at the contact surface during the frictional process, leading to the distinct blackening phenomenon. © 2024, The Authors. All rights reserved.

关键词： Polyimides

Research on the Application of Digital Twin in Bridge Rotation Construction

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Research on the Application of Digital Twin in Bridge Rotati...

International Conference on Computer Network, Electronic and Automation (ICCNEA)

作者： Yanming Liu Fei Xu Zhenghua Yang Yan Deng Xing Wang State Key Laboratory of Rail Transit Engineering Informatization(FSDI) Xi'an China School of Computer Science and Engineering Xi'an Technological University Xi'an China School of Architecture and Engineering Xi'an Technological University Xi'an China School of Ordnance Science and Technology Xi'an Technological University Xi'an China

With the continuous expansion of China's high-speed railway network, the construction of bridges spanning existing railway lines has become increasingly common. Bridge transition, as a solution for constructing bridges on existing tracks, is crucial for ensuring safety during the construction phase. This research aims to utilize digital twin technology to monitor the construction of bridge transitions and address the limitations of traditional bridge monitoring methods. We employed the Unity3D game engine to create a digital twin virtual scene and facilitated seamless data exchange between the physical and virtual domains using the OPC UA data exchange mechanism. Ultimately, we developed a prototype system for monitoring bridge transition construction. This system effectively monitors critical information and activities during bridge construction, providing early warning capabilities and decision support throughout the construction process. Through the design and implementation of the system prototype, we have confirmed the feasibility of applying digital twin technology in bridge transition construction.

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Phase Fringe Suppression of Background Deformation for Nondestructive Testing Based on Shearography

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IEEE Transactions on Instrumentation and Measurement 2025年 74卷

作者： Wang, Yonghong Zheng, Zihua Liu, Xiangwei Yan, Peizheng Li, Junrui Zhu, Zhenmin Hefei University of Technology School of Instrument Science and Opto-Electronics Engineering Anhui Province Key Laboratory of Measuring Theory and Precision Instrument Anhui Hefei230009 China East China Jiaotong University State Key Laboratory of Performance Monitoring Protecting of Rail Transit Infrastructure Nanchang330013 China

Shearography, a commonly utilized method for nondestructive testing (NDT), offers the advantage of full-field, noncontact, and real-time inspection across extensive viewing areas. Nonetheless, the effectiveness of defect detection using this method is frequently compromised by background deformation, posing challenges in accurately determining defect sizes and locations. This study investigates the deformation observed in specimens during shearography defect detection and introduces a background fringe suppression strategy based on deep learning. The aforementioned approach, which incorporates a robust dataset generation methodology and an advanced network architecture, excels at processing noisy wrapped phase maps, thereby efficiently discerning and mitigating background fringes. The effectiveness of the proposed method is corroborated through simulated and actual defect detection experiments, underscoring its potential in enhancing the precision of shearography defect detection. © 2025 IEEE. All rights reserved.

关键词： Deformation Laser beams Training Testing Speckle Holography Fitting Defect detection Mirrors Lead zirconate titanate

Wheel Tread Temperature Assessment and its Impact on Rolling Contact Fatigue Under Braking Conditions

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SSRN 2024年

作者： Wang, Bo Wu, Qing Luo, Shihui Spiryagin, Maksym Ma, Weihua Ding, Haohao Yang, Zhongliang State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong University Chengdu China Centre for Railway Engineering Central Queensland University Rockhampton Australia China Railway Beijing China

This paper proposes a numerical analysis method for wheel-rail-pad temperature and wheel thermal damage based on thermodynamics, material mechanics, and wheel-rail contact mechanics. This method has features of simplicity and fast computing speed. The study shows that the temperature rise of the wheel tread is mainly affected by the thermal friction between the brake pad and the wheel tread. The effects of track gradient, braking speed, and ambient temperature on wheel tread temperature rise are 16°C/‰, 9.4°C/km▪h−1, and 10°C/°C, respectively. The study shows that the value of rolling contact fatigue considering the temperature rise of the wheel tread is about 1.55 times that without considering the temperature rise, while the value of wear damage is reduced by 23%. © 2024, The Authors. All rights reserved.

关键词： Thermal fatigue

Adaptive Backstepping Sliding Mode Control of High-speed Train Based on Fuzzy Regulation 5

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Adaptive Backstepping Sliding Mode Control of High-speed Tra...

5th International Conference on Industrial Artificial Intelligence, IAI 2023

作者： Fu, Yating Tian, Junhao Yang, Hui East China Jiaotong University State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure Nanchang330013 China East China Jiaotong University Key Laboratory of Advanced Control and Optimization of Jiangxi Province Nanchang330013 China East China Jiaotong University School of Electrical and Automation Engineering Nanchang330013 China East China Jiaotong University Nanchang330013 China

ISBN: (纸本)9798350325294

In order to meet the operational requirements of the high-speed train in terms of safety, accuracy and smoothness, an adaptive backstepping sliding mode control approach based on fuzzy regulation is put forward in this paper. Firstly, to solve the problem of insufficient accuracy of the single point model, this paper establishes a mass point dynamics model of the high-speed train and sets a compensation term for the model considering the uncertainties in the operation process. Secondly, the adaptive law is designed to estimate the compensation term and the new backstepping sliding mode control strategy is developed. Finally, fuzzy rules are designed to adjust the switching gain of the sliding mode term to suppress jitter. The results of simulation and comparison experiments demonstrate the effectiveness and feasibility of the proposed modeling and control method. © 2023 IEEE.

关键词： railroads

Acoustic Comfort Evaluation of High-Speed Trains in Tunnels Based on Eeg Signals

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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

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

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Analytical Solution of Mechanical Response in Large Diameter...

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

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

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Analysis of Stray Magnetic Field of Superconducting Magnets ...

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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