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2021 6th International Seminar on Advances in Materials Science and engineering, ISAMSE 2021

作者： Ding, Yanjie State key Laboratory of Rail Transit Engineering Informatization China Railway First Survey and Design Institute Group Co. Ltd Xi'an710043 China

In the construction technology of an earth pressure balance (EPB) shield, soil conditioning is an important technology. It is possible to condition the properties of excavation soil and improve the excavation efficiency by injecting suitable conditioners. Soil conditioning is more important in cohesionless stratum because the flow plasticity of this stratum is typically poor. The soil is conditioned by the interaction between the soil particles and the soil conditioners, the internal principles of which need to be investigated by microscopic tests. Based on the CT test, the changes in porosity after soil conditioning were analyzed, and it was revealed that soil conditioners can make pores form separate structures. Based on the SEM test, the mechanism for the reduction in porosity of the soil was obtained: the flakes formed by the conditioners replaced the original pores. © 2021 Institute of Physics Publishing. All rights reserved.

关键词： Soils

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Anisotropic strength,deformation and failure of gneiss granite under high stress and temperature coupled true triaxial compression

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岩石力学与岩土工程学报（英文版） 2024年第3期16卷 860-876页

作者： Hongyuan Zhou Zaobao Liu Fengjiao Liu Jianfu Shao Guoliang Li Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines College of Resources and Civil EngineeringNortheastern UniversityShenyang110819China Institute of Deep Engineering and Intelligent Technology Northeastern UniversityShenyang110819China University Lille CNRSCentrale LilleUMR 9013-LaMcube-Laboratoire de MécaniqueMultiphysiqueMulti-échelleF-59000LilleFrance Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines College of Resources and Civil EngineeringNortheastern UniversityShenyang110819China Institute of Deep Engineering and Intelligent Technology Northeastern UniversityShenyang110819China Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines College of Resources and Civil EngineeringNortheastern UniversityShenyang110819China University Lille CNRSCentrale LilleUMR 9013-LaMcube-Laboratoire de MécaniqueMultiphysiqueMulti-échelleF-59000LilleFrance State Key Lab on Rail & Transit Engineering Informatization China Railway First Survey and Design Institute Group Co.LtdXi'an710043China

The anisotropic mechanical behavior of rocks under high-stress and high-temperature coupled condi-tions is crucial for analyzing the stability of surrounding rocks in deep underground *** paper is devoted to studying the anisotropic strength,deformation and failure behavior of gneiss granite from the deep boreholes of a railway tunnel that suffers from high tectonic stress and ground temper-ature in the eastern tectonic knot in the Tibet ***-temperature true triaxial compression tests are performed on the samples using a self-developed testing device with five different loading directions and three temperature values that are representative of the geological conditions of the deep under-ground tunnels in the *** of temperature and loading direction on the strength,elastic modulus,Poisson's ratio,and failure mode are *** method for quantitative identification of anisotropic failure is also *** anisotropic mechanical behaviors of the gneiss granite are very sensitive to the changes in loading direction and temperature under true triaxial compression,and the high temperature seems to weaken the inherent anisotropy and stress-induced deformation *** strength and deformation show obvious thermal degradation at 200℃ due to the weakening of friction between failure surfaces and the transition of the failure pattern in rock *** the range of 25 ℃-200 ℃,the failure is mainly governed by the loading direction due to the inherent *** study is helpful to the in-depth understanding of the thermal-mechanical behavior of anisotropic rocks in deep underground projects.

关键词： Anisotropic strength and deformation True triaxial compression Thermal mechanical coupling Deep rock mechanics High temperature rock mechanics

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Elastic-viscoplastic behaviors of polymer-blend geocell sheets:Numerical and experimental investigations

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Journal of Rock Mechanics and Geotechnical engineering 2024年第10期16卷 4261-4271页

作者： Yang Zhao Jianbin Chen Zheng Lu Jie Liu Abdollah Tabaroei Chuxuan Tang Yong Wang Lipeng Wu Bo Wang Hailin Yao State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China Wuhan Municipal Engineering Design&Research Institute Co. Ltd.Wuhan430023China Hubei Key Laboratory of Geo-Environmental Engineering Wuhan430071China Xinjiang Transportation Planning Survey and Design Institute Co. Ltd.Urumqi830006China Department of Civil Engineering Eshragh Institute of Higher EducationBojnourd***Iran University of Chinese Academy of Sciences Beijing100049China China Energy Engineering Gezhouba Rail Transit Construction Co. Ltd.Shenzhen518116China

Polymer-blend geocell sheets(PBGS)have been developed as substitute materials for manufacturing *** attempts have been made to test and predict the behaviors of commonly used geogrids,geotextiles,geomembranes,and ***,the elastic-viscoplastic behaviors of novel-developed geocell sheets are still poorly ***,this paper investigates the elastic-viscoplastic behaviors of PBGS to gain a comprehensive understanding of their mechanical ***,the tensile load-strain history under various loading conditions is simulated by numerical calculation for widespread *** achieve this goal,monotonic loading tests,short-term creep and stress relaxation tests,and multi-load-path tests(also known as arbitrary loading history tests)are performed using a universal testing *** results are simulated using the nonlinear three-component(NLTC)model,which consists of three nonlinear components,i.e.a hypo-elastic component,a nonlinear inviscid component,and a nonlinear viscid *** experimental and numerical results demonstrate that PBGS exhibit significant elastic-viscoplastic behavior that can be accurately predicted by the NLTC ***,the tensile strain rates significantly influence the tensile load,with higher strain rates resulting in increased tensile loads and more linear load-strain ***,parametric analysis of the rheological characteristics reveals that the initial tensile strain rates have negligible impact on the *** rate-sensitivity coefficient of PBGS is approximately 0.163,which falls within the typical range observed in most geosynthetics.

关键词： Polymer-blend geocell sheets Geosynthetics Elastic-viscoplastic behavior Numerical simulations Tensile load-strain response

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Prediction of railway Track Curvature Using OpenStreetMap 3

Prediction of Railway Track Curvature Using OpenStreetMap

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3rd International Conference on rail Transportation, ICRT 2024

作者： Zhou, Yichang Ren, Zunsong Ye, Yunguang Hecht, Markus School of Mechanical Electronic and Control Engineering Beijing Jiaotong Univ. Beijing China State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong Univ. Chengdu China Institute of Land and Sea Transport Systems Technische Universität Berlin Berlin Germany

ISBN: (数字)9780784485941

ISBN: (纸本)9780784485941

railway track curvature is a critical parameter, which directly affects vehicle-track dynamics, such as running speed and wheel-rail interaction. Therefore, knowing track curvature can help wagon operators better understand the running condition of vehicles and further take effective measures to monitor or maintain their health. This paper aims to predict horizontal track curvature by using OpenStreetMap (OSM), an open and free geographic database. A field test was carried out when a train was operated on the Blankenburg-Bernburg railway line in Germany. At first, the running trajectory of the vehicle is measured by the GPS sensor with a frequency of 5 Hz and then it is converted to Cartesian coordinates, where the curvature of the trajectory is calculated. Second, an improved method to increase the accuracy by integrating with the OSM database is proposed, and the procedure of this improved method is presented. © ASCE.

关键词： railroads

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Time-dependent reliability analysis of track slab in cold region under different thermal insulation measures

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Construction and Building Materials 2025年 460卷

作者： Liu, Wengao Deng, Shijie Ren, Juanjuan Zhang, Zeyong Xu, Huan Ye, Wenlong Yang, Junbin MOE Key Laboratory of High-speed Railway Engineering School of Civil Engineering Southwest Jiaotong University Chengdu610031 China State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong University Chengdu610031 China

In cold regions, slab track structures face extreme conditions, such as low temperatures, significant temperature differences, and repeated freeze-thaw cycles, posing severe challenges to their long-term operational stability and reliability. In this study, we carried out a train load field test and a full-scale test of the temperature field of the slab track, and the probability distributions of wheel-rail forces and temperature gradients were determined. Random load samples were generated using the Latin Hypercube Sampling (LHS) method, and the load effects of the track slab under train loads and temperature gradients were analyzed. In addition, the time-dependent resistance model of the track slab was established by combining the freeze-thaw cycle tests. The Monte Carlo Importance Sampling (MCIS) method was adopted to analyze the time-dependent reliability of the crack resistance and flexural strength under different insulation measures. It was found that the Polyurethane Foam Board (PFB) and Rubber Plastic Board (RPB) could effectively reduce the temperature gradient and load effect of the track slab. Thermal insulation measures can significantly improve the time-dependent reliability of track slabs, and the research results can provide theoretical reference for guaranteeing long-term stable service performance of slab track in cold regions. © 2025

关键词： Importance sampling

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Sc/Zr ratio-dependent mechanisms of strength evolution and microstructural thermal stability of multi-scale hetero-structured Al-Mg-Sc-Zr alloys

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材料科学技术（英文版） 2023年第9期140卷 67-78页

作者： Min Zha Teng Tian Hai-Long Jia Hong-Min Zhang Hui-Yuan Wang Key Laboratory of Automobile Materials of Ministry of Education & School of Materials Science and Engineering Nanling CampusJilin UniversityChangchun 130025China International Center of Future Science Jilin UniversityChangchun 130012China State Key Laboratory of Superhard Materials Jilin UniversityChangchun 130012China Key Laboratory of Automobile Materials of Ministry of Education & School of Materials Science and Engineering Nanling CampusJilin UniversityChangchun 130025China School of Mechanical Engineering and Rail Transit Changzhou UniversityChangzhou 213164China

Microstructure and its thermal stability are critical in the development of high-performance Al-Mg ***,we attempt to tailor Al3(Sc,Zr)precipitates and thus microstructure characteristics to manipulate mechanical properties and microstructural stability of Al-7Mg alloys fabricated by hot extrusion com-bined with two-pass hard-plate rolling via changing Sc/Zr *** Sc/Zr ratio leads to improved strength without any loss of ductility.A strength-ductility synergy,*** strength of～548 MPa and ultimate tensile strength of～605 MPa with an impressive ductility of～10％elongation was achieved in the Al-7Mg-0.3Sc-0.1Zr *** good strength-ductility synergy is ascribed to the multi-scale het-erogeneous microstructure promoted by the high Sc/Zr ratio,i.e.a bimodal grain structure,profuse low angle grain boundaries,dispersed nano-sized Al3(Sc,Zr)precipitates coexisting with intragranular Mg-Zr co-clusters segregated at *** thermal exposure,the Al-7Mg-0.3Sc-0.1Zr alloy maintained higher hardness at below 250 ℃,whereas Al-7Mg-0.2Sc-0.2Zr and Al-7Mg-0.1Sc-0.3Zr alloys exhibited higher hardness in moderate-and high-temperature range of 250-350 ℃ and ≥ 400 ℃,***-probe tomography analysis illustrates that slow-diffusing Zr atoms enhance Al3(Sc,Zr)coarsening resistance through forming a higher-content Zr-enriched protective shell around a Sc-enriched core in ***,the high Zr content promotes concurrent Al3(Sc,Zr)precipitation during thermal exposure at high *** improved microstructural thermal stability in Al-7Mg-0.1Sc-0.3Zr alloy is further discussed in terms of the recrystallization resistance and grain growth *** present study reveals the feasibility for designing high-strength and thermally stable hetero-structured Al-Mg-Sc-Zr alloys via tailoring Sc/Zr ratios for different application temperature ranges.

关键词： Al–Mg alloys Al3(Sc Zr) Strength Thermal stability Bimodal grain structure

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An Extensive Review of Tribo-Dynamic Modelling for Rolling Element Bearing Condition Monitoring

An Extensive Review of Tribo-Dynamic Modelling for Rolling E...

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UNIfied Conference of International Workshop on Defence Applications of Multi-Agent Systems, DAMAS 2023, International Conference on Maintenance engineering, IncoME-V 2023, International conference on the Efficiency and Performance engineering Network, TEPEN 2023

作者： Zhou, Zewen Chen, Bingyan Gong, Xue Sun, Xiuquan Hu, Zhifeng Rabeyee, Khalid Gu, Fengshou Ball, Andrew D. Muhamedsalih, Yousif Centre for Efficiency and Performance Engineering University of Huddersfield HuddersfieldHD1 3DH United Kingdom State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong University Chengdu610031 China Department of Mechanics Tianjin University Tianjin300350 China

ISBN: (纸本)9783031494123

Dynamic modelling is widely used to study the vibration characteristics and failure mechanisms of rolling element bearings, which is the primarily important for accurate condition monitoring. The dynamic coupling between tribology and dynamics is deemed as the most important phenomena yet is also a complex and challenging task that has received substantial attention in recent years in order to leverage bearing service performance. This paper comprehensively reviews the tribological and dynamic simulation studies of rolling bearings, which includes elastohydrodynamic lubrication, rough surfaces and interfacial clearances. The state-of-the-art works on tribo-dynamic modelling of rolling bearings are summarised and overviewed. The current challenges in dynamic tribology of rolling bearings are elaborated and future research directions are suggested. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.

关键词： Elastohydrodynamic lubrication

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Numerical simulation of irregular section underground structure shaking table test model

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Earthquake Research Advances 2022年第4期2卷 53-59页

作者： Baizan Tang Wenchao Deng Su Chen Xiaojun Li Haiyang Zhuang State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure East China Jiaotong UniversityNanchang330013China Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin150086China Faculty of Architecture Civil and Transportation EngineeringBeijing University of TechnologyBeijing100124China

Based on the the large shaking table test results on irregular section subway station structure in soft soil,an overall time-history numerical simulation is conducted to study the nonlinear dynamic interaction of the soilirregular underground *** test results,including the acceleration of the soil,acceleration,and deformation of the structure,were *** consistency between the simulation and test results is verified,and the difference between these results was discussed in *** maximum inter-story drift ratio was approximately 1/472 under input PGA=0.54 *** strain responses of columns were significantly larger than those of the side walls and *** components in the lower layers of the irregular subway station structure,particularly in the central columns,underwent cumulative *** research results could provide a simplified analysis method to quantitatively evaluate the damage of irregular underground structures in soft soil.

关键词： Irregular section subway station Soft soil Seismic response Numerical simulation Shaking table test

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VIBRATION ABSORPTION FROM PLATES USING PERIODIC ADDITIVE ACOUSTIC BLACK HOLES 30

VIBRATION ABSORPTION FROM PLATES USING PERIODIC ADDITIVE ACO...

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30th International Congress on Sound and Vibration, ICSV 2024

作者： Deng, Jie Chen, Xu Yang, Yi Qin, Zhaoye Guo, Wenjie Chongqing Industry Polytechnic College Chongqing401120 China group Department of Engineering La Salle Universitat Ramon Llull C/Quatre Camins 30 Catalonia Barcelona08022 Spain State Key Laboratory of Mechanical Transmission College of Mechanical and Vehicle Engineering Chongqing University Chongqing400044 China State Key Laboratory of Traction Power Southwest Jiaotong University Chengdu610031 China State Key Laboratory of Tribology Department of Mechanical Engineering Tsinghua University Beijing100084 China State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure East China Jiaotong University Nanchang330013 China

ISBN: (纸本)9789090390581

We propose a composite structure with periodic additive acoustic black holes (ABH) to absorb vibrations from plates. Different from conventional embedded ABHs, this additive configuration no longer compromises structural integrity. A theoretical model is constructed to characterize the vibration of the coupled structure using Gaussian expansion method (GEM) and nullspace method (NSM). A finite plate with 4 × 4 cells has been examined. Results show that the additive ABHs can significantly mitigate the vibration of the host plate, even at low frequencies. © 2024 Proceedings of the International Congress on Sound and Vibration. All rights reserved.

关键词： Composite structures

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Energy-Efficient Operation of Train Platoons in Urban rail transit Systems: An MIP Approach 43

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

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43rd Chinese Control Conference, CCC 2024

作者： Li, Haodong Yin, Jiateng Tang, Tao D'Ariano, Andrea You, Mengxing Beijing Jiaotong University State Key Laboratory of Advanced Rail Autonomous Operation Beijing100044 China Beijing Jiaotong University School of Systems Science Beijing100044 China RomaTre Universily Computer Science and Aeronautical Technologies Engineering Department of Civi Rome0018511 Italy Nanchang Rail Transit Group CO. Ltd Jiangxi330038 China

ISBN: (纸本)9789887581581

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 industry. Our study investigates the energy-efficient operation of train platoons to reduce the energy consumption of trains while satisfying time-varying passenger demands in practice. We develop a mixed integer programming (MIP) model to optimize the timetable, running speed and coupling strategies of trains. Considering 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 trains. We 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 trains. Finally, we conduct real-world case studies on the Beijing subway Yizhuang line to verify the effectiveness of our approach. The results indicate that the energy-efficient operation of train platoons can achieve a better trade-off between service quality and system energy consumption. © 2024 Technical Committee on Control Theory, Chinese Association of Automation.

关键词： Energy efficiency

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