Pub Date : 2023-10-08DOI: 10.1080/23248378.2023.2264866
Jinnan Wang, Muhammad Qasim Zafar, Yunbo Chen, Lingli Zuo, Xiangjun Zhang, Pu Xie, Haiyan Zhao
ABSTRACTHigh-speed train brake discs face severe service conditions and subsequently risk of material failure during emergency braking. Thermal fatigue cracking is a major concern leading to catastrophic disc failure and is regarded as a primary service bottleneck in rapid rail transportation. Our proposed work establishes a numerical prediction model to estimate thermal fatigue crack initiation and propagation in low-alloy steel. We used a modified Cockcroft-Latham criterion and material property tests to determine the critical crack initiation value. Through numerical simulations and in-situ experiments, we observed plastic deformation at the median temperature of the thermal fatigue cycle and found that tailored material composition improves brake disc fatigue performance. This research aims to enhance understanding of the cracking mechanism and improve the reliability of brake systems for high-speed trains.KEYWORDS: High-speed trainbrake discnumerical simulationcrack damage modelthermal fatigue crack Disclosure statementNo potential conflict of interest was reported by the authors.Additional informationFundingThis work was funded by the National Natural Science Foundation of China (Grant No 51975316), National Natural Science Foundation of China (Grant No. 51975320), the Beijing Natural Science Foundation (No. M22011), and the National Key R&D Program of China (No. 2017YFB1103300).
{"title":"Numerical simulation and mechanism analysis of thermal fatigue crack for low-alloy steel brake disc of high-speed train","authors":"Jinnan Wang, Muhammad Qasim Zafar, Yunbo Chen, Lingli Zuo, Xiangjun Zhang, Pu Xie, Haiyan Zhao","doi":"10.1080/23248378.2023.2264866","DOIUrl":"https://doi.org/10.1080/23248378.2023.2264866","url":null,"abstract":"ABSTRACTHigh-speed train brake discs face severe service conditions and subsequently risk of material failure during emergency braking. Thermal fatigue cracking is a major concern leading to catastrophic disc failure and is regarded as a primary service bottleneck in rapid rail transportation. Our proposed work establishes a numerical prediction model to estimate thermal fatigue crack initiation and propagation in low-alloy steel. We used a modified Cockcroft-Latham criterion and material property tests to determine the critical crack initiation value. Through numerical simulations and in-situ experiments, we observed plastic deformation at the median temperature of the thermal fatigue cycle and found that tailored material composition improves brake disc fatigue performance. This research aims to enhance understanding of the cracking mechanism and improve the reliability of brake systems for high-speed trains.KEYWORDS: High-speed trainbrake discnumerical simulationcrack damage modelthermal fatigue crack Disclosure statementNo potential conflict of interest was reported by the authors.Additional informationFundingThis work was funded by the National Natural Science Foundation of China (Grant No 51975316), National Natural Science Foundation of China (Grant No. 51975320), the Beijing Natural Science Foundation (No. M22011), and the National Key R&D Program of China (No. 2017YFB1103300).","PeriodicalId":48510,"journal":{"name":"International Journal of Rail Transportation","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135197994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-30DOI: 10.1080/23248378.2023.2259392
Tim Vernaillen, Li Wang, Alfredo Núñez, Rolf Dollevoet, Zili Li
This paper presents a big data-based analysis of the rail wear of the whole Belgian railway network measured in 2012 and 2019. Wear rates are reported, discussed, and quantitatively formulated as functions of critical factors in terms of curve radius, annual tonnage (rail age), high rail in curves, an average from both rails in straight tracks at rail top (vertical wear) and gauge corner (45° wear) and for steel grade R200 and R260. The influence of preventive grinding is also analysed. The wear rates are derived in an aggregated manner for the whole network. The wear rates do not show significant change with changes in rolling stock over the years, implying that the wear rates could also hold for other networks. It is found that R200 shows, on average, a 34% higher wear rate than R260. Also, the wear rate per tonnage is lower for high-loaded tracks. Thus, time is a relevant factor in explaining the wear evolution of low-loaded tracks; for instance, the effect of corrosion may have an important role. The paper provides statistically significant information that can be used for wear modelling, understanding and treating rolling contact fatigue based on the wear rate and developing tailored rail maintenance strategies.
{"title":"Rail wear rate on the Belgian railway network – a big-data analysis","authors":"Tim Vernaillen, Li Wang, Alfredo Núñez, Rolf Dollevoet, Zili Li","doi":"10.1080/23248378.2023.2259392","DOIUrl":"https://doi.org/10.1080/23248378.2023.2259392","url":null,"abstract":"This paper presents a big data-based analysis of the rail wear of the whole Belgian railway network measured in 2012 and 2019. Wear rates are reported, discussed, and quantitatively formulated as functions of critical factors in terms of curve radius, annual tonnage (rail age), high rail in curves, an average from both rails in straight tracks at rail top (vertical wear) and gauge corner (45° wear) and for steel grade R200 and R260. The influence of preventive grinding is also analysed. The wear rates are derived in an aggregated manner for the whole network. The wear rates do not show significant change with changes in rolling stock over the years, implying that the wear rates could also hold for other networks. It is found that R200 shows, on average, a 34% higher wear rate than R260. Also, the wear rate per tonnage is lower for high-loaded tracks. Thus, time is a relevant factor in explaining the wear evolution of low-loaded tracks; for instance, the effect of corrosion may have an important role. The paper provides statistically significant information that can be used for wear modelling, understanding and treating rolling contact fatigue based on the wear rate and developing tailored rail maintenance strategies.","PeriodicalId":48510,"journal":{"name":"International Journal of Rail Transportation","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136342185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACTThe vibration caused by urban rail transit has led to numerous severe environmental issues. The floating slab track (FST) plays an important role in vibration control and noise reduction for rail transit. In this study, a novel phononic crystal vibration isolator (NPCVI) is developed based on the principle of local resonance to address the deficiencies in the low frequency vibration reduction of existing FST with steel spring vibration isolators (SSVI). The vibration equation of the NPCVI is derived and an analytical method for the dynamic interaction between vehicle, track, and tunnel is proposed. The pseudo excitation method (PEM) is introduced to solve the random vibration response of the vehicle-track-tunnel coupled system under the excitation of full-band track random irregularity. The numerical simulation results are compared with the field measurement results to verify the correctness of the solution model. The vibration reduction analysis of FST using NPCVI is conducted within a system dynamics framework, and a comparison is made between the performance of the conventional SSVI and the proposed NPCVI while a train is passing. The vibration reduction optimization effect of the NPCVI is evaluated using the vibration level (VL) of the tunnel structure. The results demonstrate that the NPCVI exhibits a superior band gap width as compared to that of the SSVI.KEYWORDS: Urban rail transitfloating slab trackvibration isolatorvibration reductionphononic crystals AcknowledgementsThis research was supported by the National Natural Science Foundation of China (No. 52178436), and sponsored by Shanghai Collaborative Innovation Research Center for Multi-network & Multi-modal Rail Transit.Authorship contribution statementXinwen Yang: Methodology, Supervision, Funding acquisition, Writing – review & editing. Yingjie Zhang: Data curation, Validation, Software. Zhao Zhang: Conceptualization, Methodology, Software, Writing – original draft. Yanyan Zhang: Data curation, Visualization, Investigation.Disclosure statementThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.Additional informationFundingThe work was supported by the the National Natural Science Foundation of China [No. 52178436].
{"title":"Effect of novel phononic crystals vibration isolator on vibration reduction for floating slab track considering the random dynamical load of the vehicle","authors":"Xinwen Yang, Yingjie Zhang, Zhao Zhang, Yanyan Zhang","doi":"10.1080/23248378.2023.2261445","DOIUrl":"https://doi.org/10.1080/23248378.2023.2261445","url":null,"abstract":"ABSTRACTThe vibration caused by urban rail transit has led to numerous severe environmental issues. The floating slab track (FST) plays an important role in vibration control and noise reduction for rail transit. In this study, a novel phononic crystal vibration isolator (NPCVI) is developed based on the principle of local resonance to address the deficiencies in the low frequency vibration reduction of existing FST with steel spring vibration isolators (SSVI). The vibration equation of the NPCVI is derived and an analytical method for the dynamic interaction between vehicle, track, and tunnel is proposed. The pseudo excitation method (PEM) is introduced to solve the random vibration response of the vehicle-track-tunnel coupled system under the excitation of full-band track random irregularity. The numerical simulation results are compared with the field measurement results to verify the correctness of the solution model. The vibration reduction analysis of FST using NPCVI is conducted within a system dynamics framework, and a comparison is made between the performance of the conventional SSVI and the proposed NPCVI while a train is passing. The vibration reduction optimization effect of the NPCVI is evaluated using the vibration level (VL) of the tunnel structure. The results demonstrate that the NPCVI exhibits a superior band gap width as compared to that of the SSVI.KEYWORDS: Urban rail transitfloating slab trackvibration isolatorvibration reductionphononic crystals AcknowledgementsThis research was supported by the National Natural Science Foundation of China (No. 52178436), and sponsored by Shanghai Collaborative Innovation Research Center for Multi-network & Multi-modal Rail Transit.Authorship contribution statementXinwen Yang: Methodology, Supervision, Funding acquisition, Writing – review & editing. Yingjie Zhang: Data curation, Validation, Software. Zhao Zhang: Conceptualization, Methodology, Software, Writing – original draft. Yanyan Zhang: Data curation, Visualization, Investigation.Disclosure statementThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.Additional informationFundingThe work was supported by the the National Natural Science Foundation of China [No. 52178436].","PeriodicalId":48510,"journal":{"name":"International Journal of Rail Transportation","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134958795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACTTo investigate the influence of debonding-repair materials on interface damage and deformation characteristics in track structures, a finite element model was established to represent CRTS III prefabricated slab track with debonding repairment under various conditions. The mechanical properties and deformation law of the track structure under the combined loads of train and temperature gradient were analysed under intact interlayer, debonding without repairment, and debonding-repaired conditions. Results show that both the interface damage area and stress increase in line with the temperature gradient, and that positive temperature gradients have a greater effect on interface damage than negative temperature gradients. In addition, the interface damage area and stress increase can be effectively slowed down with debonding repairment materials. Specifically, under a temperature gradient of 90°C/m, the failure rate of interfacial bonds is 21.2%, 29.6%, and 2.1% for conditions of intact interlayer, debonding without repairment, and debonding with repairment, respectively. In debonding conditions, the maximum vertical displacements along the lateral and longit udinal direction increase about 1.1 times ~ 2.3 times under positive temperature gradients more than the intact interlayer condition. Further, the pattern and peak vertical deformation for track slab are basically the same between the intact interlayer and the repaired debonding conditions. The calculation results indicate that the repair measures can alleviate interfacial adhesive deterioration and reduce the deformation of the track structures.KEYWORDS: Slab trackdebonding repairmenttemperature loadinterface damagedeformation characteristics Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThe research is supported by the National Key R&D Program of China (No. 2021YFF0502100), the National Natural Science Foundation of China (No. 52022085, 52278461), and the Sichuan Province Youth Science and Technology Innovation Team (No. 2022JDTD0015), whose support are gratefully acknowledged. The results and opinions presented are those of the authors and do not necessarily reflect those of the sponsoring agencies.
{"title":"Analysis of mechanical properties and deformation characteristics of debonding-repaired slab track","authors":"Wei Du, Juanjuan Ren, Wengao Liu, Kaiyao Zhang, Shijie Deng, Guihong Xu","doi":"10.1080/23248378.2023.2261478","DOIUrl":"https://doi.org/10.1080/23248378.2023.2261478","url":null,"abstract":"ABSTRACTTo investigate the influence of debonding-repair materials on interface damage and deformation characteristics in track structures, a finite element model was established to represent CRTS III prefabricated slab track with debonding repairment under various conditions. The mechanical properties and deformation law of the track structure under the combined loads of train and temperature gradient were analysed under intact interlayer, debonding without repairment, and debonding-repaired conditions. Results show that both the interface damage area and stress increase in line with the temperature gradient, and that positive temperature gradients have a greater effect on interface damage than negative temperature gradients. In addition, the interface damage area and stress increase can be effectively slowed down with debonding repairment materials. Specifically, under a temperature gradient of 90°C/m, the failure rate of interfacial bonds is 21.2%, 29.6%, and 2.1% for conditions of intact interlayer, debonding without repairment, and debonding with repairment, respectively. In debonding conditions, the maximum vertical displacements along the lateral and longit udinal direction increase about 1.1 times ~ 2.3 times under positive temperature gradients more than the intact interlayer condition. Further, the pattern and peak vertical deformation for track slab are basically the same between the intact interlayer and the repaired debonding conditions. The calculation results indicate that the repair measures can alleviate interfacial adhesive deterioration and reduce the deformation of the track structures.KEYWORDS: Slab trackdebonding repairmenttemperature loadinterface damagedeformation characteristics Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThe research is supported by the National Key R&D Program of China (No. 2021YFF0502100), the National Natural Science Foundation of China (No. 52022085, 52278461), and the Sichuan Province Youth Science and Technology Innovation Team (No. 2022JDTD0015), whose support are gratefully acknowledged. The results and opinions presented are those of the authors and do not necessarily reflect those of the sponsoring agencies.","PeriodicalId":48510,"journal":{"name":"International Journal of Rail Transportation","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134886411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-21DOI: 10.1080/23248378.2023.2256731
Chao Wen, Wenxin Li, Qiang Ma, Guanming Wang, Baoquan Tao
ABSTRACTThe complex electricity transmission process and transfer passenger demand in the rail transit system make it challenging to formulate optimal timetables and train speed profiles to meet the needs of the system. This study optimizes train timetable to meet energy conservation and passenger service quality of cross-mode rail transit system during different operation periods. Firstly, based on the spatiotemporal travel data of transfer passengers, the train-time matrix is proposed to construct a bi-objective optimization model (BOOM) that incorporates the total energy consumption optimization model (TECOM) and total waiting time optimization model of transfer passenger (TWTOM). It can better combine the passenger transport scheme and the train energy-saving operation strategy, thus improving energy-saving performance and passenger transport efficiency and simplifying the difficulty of mathematical modelling of such BOOM. Then, a method for determining the appropriate weight coefficient ratio and the improved non-dominated sorting genetic algorithm II (NSGA-II) are applied to obtain the efficient Pareto front solutions. Taking the numerical experiments as test cases, the improved NSGA-II can get a efficient solution faster than the traditional NSGA-II. Finally, two numerical experiments using real-world data are conducted to verify the practicability of the optimization model and the effectiveness of improved NSGA-II. The optimization results can reduce energy consumption by up to 11.02% and passenger waiting time by 137,320 s, respectively. This study helps to improve the energy efficiency and passenger service quality of cross-mode rail transit systems, and also provides a reference for dispatchers to optimize train timetable.KEYWORDS: Transportation systemtimetable optimizationenergy conservationtransfer passengerimproved NSGA-II AcknowledgementsThis work was supported by Science and technology research project of Hubei Provincial Department of Education (No. Q20222606). The authors also acknowledge the Open Fund of Hubei Key Laboratory of Power System Design and Test for Electrical Vehicle, Hubei Superior and Distinctive Discipline Group of “New Energy Vehicle and Smart Transportation”. Finally, the authors are grateful for the useful contributions made by their project partners.Disclosure statementNo potential conflict of interest was reported by the authors.Author contributions statementChao Wen: Methodology, Validation, Software, Data curation, Writing-Original draft preparation. Wenxin Li: Conceptualization, Methodology, Supervision, Writing- Reviewing and Editing, Funding acquisition. Qiang Ma: Conceptualization, Methodology, Funding acquisition. Guanming Wang and Baoquan Tao: Writing- Reviewing and Editing.Data availability statementThe data that support the findings of this study are available from the authors on reasonable request.Statements and DeclarationsThis manuscript has not been published or presented elsewhere in part or
{"title":"Joint optimization of energy conservation and transfer passenger service quality in rail transit system","authors":"Chao Wen, Wenxin Li, Qiang Ma, Guanming Wang, Baoquan Tao","doi":"10.1080/23248378.2023.2256731","DOIUrl":"https://doi.org/10.1080/23248378.2023.2256731","url":null,"abstract":"ABSTRACTThe complex electricity transmission process and transfer passenger demand in the rail transit system make it challenging to formulate optimal timetables and train speed profiles to meet the needs of the system. This study optimizes train timetable to meet energy conservation and passenger service quality of cross-mode rail transit system during different operation periods. Firstly, based on the spatiotemporal travel data of transfer passengers, the train-time matrix is proposed to construct a bi-objective optimization model (BOOM) that incorporates the total energy consumption optimization model (TECOM) and total waiting time optimization model of transfer passenger (TWTOM). It can better combine the passenger transport scheme and the train energy-saving operation strategy, thus improving energy-saving performance and passenger transport efficiency and simplifying the difficulty of mathematical modelling of such BOOM. Then, a method for determining the appropriate weight coefficient ratio and the improved non-dominated sorting genetic algorithm II (NSGA-II) are applied to obtain the efficient Pareto front solutions. Taking the numerical experiments as test cases, the improved NSGA-II can get a efficient solution faster than the traditional NSGA-II. Finally, two numerical experiments using real-world data are conducted to verify the practicability of the optimization model and the effectiveness of improved NSGA-II. The optimization results can reduce energy consumption by up to 11.02% and passenger waiting time by 137,320 s, respectively. This study helps to improve the energy efficiency and passenger service quality of cross-mode rail transit systems, and also provides a reference for dispatchers to optimize train timetable.KEYWORDS: Transportation systemtimetable optimizationenergy conservationtransfer passengerimproved NSGA-II AcknowledgementsThis work was supported by Science and technology research project of Hubei Provincial Department of Education (No. Q20222606). The authors also acknowledge the Open Fund of Hubei Key Laboratory of Power System Design and Test for Electrical Vehicle, Hubei Superior and Distinctive Discipline Group of “New Energy Vehicle and Smart Transportation”. Finally, the authors are grateful for the useful contributions made by their project partners.Disclosure statementNo potential conflict of interest was reported by the authors.Author contributions statementChao Wen: Methodology, Validation, Software, Data curation, Writing-Original draft preparation. Wenxin Li: Conceptualization, Methodology, Supervision, Writing- Reviewing and Editing, Funding acquisition. Qiang Ma: Conceptualization, Methodology, Funding acquisition. Guanming Wang and Baoquan Tao: Writing- Reviewing and Editing.Data availability statementThe data that support the findings of this study are available from the authors on reasonable request.Statements and DeclarationsThis manuscript has not been published or presented elsewhere in part or ","PeriodicalId":48510,"journal":{"name":"International Journal of Rail Transportation","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136236078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-19DOI: 10.1080/23248378.2023.2256735
Anas Alsharo, Kais Douier, Mohammed F.M. Hussein, Jamil Renno
ABSTRACTIn this study, a series of vibration measurements were performed on a section of one of the lines of the Doha Metro to explore the effect of changing rail-pads from conventional higher stiffness under-rail pads to lower stiffness web-supporting pads on the vibration levels at the free surface. Vibration levels were measured for the two cases of lower and higher stiffness’ pads at the free surface directly above the railway track. Additionally, vibration levels were measured in the railway tunnel to investigate the effect of changing rail-pad’s stiffness on the vibration levels at different locations inside the tunnel. Vibration measurements due to moving trains from the two cases were processed and analysed to calculate the Insertion Gain (IG) of vibration at the free surface and at the other locations. It was found that the use of softer rail-pads has resulted in reduction in the vibration levels at the free surface by about 10 dB for most frequencies in the range 40–200 Hz. Further numerical investigation was conducted to simulate the railway section under consideration. To simulate the track fastening system accurately, the dynamic stiffness of the rail-pads for the two cases was estimated using the measurement of vibration of rails due to impact hammer excitation and measurement of axle-box accelerations of a moving trains. The parameters of problem at-hand were used as inputs to the numerical Pipe-in-Pipe (PiP) model to calculate the insertion gain numerically at the free surface and this showed good match with the results from the measurements.KEYWORDS: Ground-borne vibrationcountermeasuresrail-padsvibration measurementsPiP model AcknowledgementsThe authors would like to acknowledge the funding from Qatar Rail through grant number QUEX-CENG-QR-21/22-1. The study received strong support by Qatar Rail in providing and supporting all logistics for the measurements.Disclosure statementNo potential conflict of interest was reported by the authors.
摘要本研究通过对多哈地铁某路段的振动测量，探讨了将常规高刚度轨下垫块改为低刚度支撑网垫块对自由面振动水平的影响。在铁路轨道正上方的自由表面上测量了低刚度和高刚度两种情况下的振动水平。此外，还在铁路隧道中测量了振动水平，研究了改变轨道垫刚度对隧道内不同位置振动水平的影响。对这两种情况下列车运动时的振动测量结果进行了处理和分析，以计算自由表面和其他位置振动的插入增益(IG)。研究发现，在40至200赫兹的频率范围内，使用较软的轨道垫可使自由表面的振动水平降低约10分贝。对所考虑的路段进行了进一步的数值模拟。为了准确地模拟轨道紧固系统，通过测量轨道在冲击锤激励下的振动和测量移动列车的轴箱加速度，估计了两种情况下轨垫的动刚度。将现有问题的参数作为数值模型的输入，对自由表面的插入增益进行了数值计算，结果与实测结果吻合较好。关键词:地面振动对策轨道垫振动测量spip模型致谢作者感谢卡塔尔铁路的资助，资助号为quex - cengr - qr -21/22-1。这项研究得到了卡塔尔铁路公司的大力支持，为测量提供了所有后勤支持。披露声明作者未报告潜在的利益冲突。
{"title":"Investigating the effect of using softer rail-pads on ground-borne vibration from underground railways","authors":"Anas Alsharo, Kais Douier, Mohammed F.M. Hussein, Jamil Renno","doi":"10.1080/23248378.2023.2256735","DOIUrl":"https://doi.org/10.1080/23248378.2023.2256735","url":null,"abstract":"ABSTRACTIn this study, a series of vibration measurements were performed on a section of one of the lines of the Doha Metro to explore the effect of changing rail-pads from conventional higher stiffness under-rail pads to lower stiffness web-supporting pads on the vibration levels at the free surface. Vibration levels were measured for the two cases of lower and higher stiffness’ pads at the free surface directly above the railway track. Additionally, vibration levels were measured in the railway tunnel to investigate the effect of changing rail-pad’s stiffness on the vibration levels at different locations inside the tunnel. Vibration measurements due to moving trains from the two cases were processed and analysed to calculate the Insertion Gain (IG) of vibration at the free surface and at the other locations. It was found that the use of softer rail-pads has resulted in reduction in the vibration levels at the free surface by about 10 dB for most frequencies in the range 40–200 Hz. Further numerical investigation was conducted to simulate the railway section under consideration. To simulate the track fastening system accurately, the dynamic stiffness of the rail-pads for the two cases was estimated using the measurement of vibration of rails due to impact hammer excitation and measurement of axle-box accelerations of a moving trains. The parameters of problem at-hand were used as inputs to the numerical Pipe-in-Pipe (PiP) model to calculate the insertion gain numerically at the free surface and this showed good match with the results from the measurements.KEYWORDS: Ground-borne vibrationcountermeasuresrail-padsvibration measurementsPiP model AcknowledgementsThe authors would like to acknowledge the funding from Qatar Rail through grant number QUEX-CENG-QR-21/22-1. The study received strong support by Qatar Rail in providing and supporting all logistics for the measurements.Disclosure statementNo potential conflict of interest was reported by the authors.","PeriodicalId":48510,"journal":{"name":"International Journal of Rail Transportation","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135060491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The influence of bogie fairing on the flow feature and aerodynamic noise performance of a high-speed train nose car model is studied based on large-eddy simulation combined with acoustic analogy approach. For the case having no fairing, the strong flow interactions and impingements occur around the bogie cavity region due to the mass addition and expulsion induced from the cavity leading edges. When a streamlined fairing is mounted outside the bogie cavity, the fluid entrainment and vortices evolvement within the bogie cavity are weakened and the shear layer impingement and flow separation outside the fairing are mitigated greatly. Thus the wall pressure fluctuations on the solid surfaces of geometries located within bogie cavity are decreased and the flow-induced noise is reduced noticeably. Based on the semi-anechoic wind tunnel measurements on a high-speed train nose car model without and with bogie fairing, it is found that the dominant sound source around bogie cavity moves from its central area to rear wall region and the aerodynamic noise is reduced effectively with a streamlined fairing mounted around the bogie cavity. The numerical predictions of aerodynamic noise are verified by the experimental measurements. The investigation would be beneficial for guiding the low-noise design and configuration optimization of a high-speed train bogie fairing.
{"title":"Effect of bogie fairing on aerodynamic and aeroacoustic behaviour of a high-speed train nose car","authors":"Jianyue Zhu, Guanda Cheng, Qiliang Li, Yu Chen, Qing Jia","doi":"10.1080/23248378.2023.2250784","DOIUrl":"https://doi.org/10.1080/23248378.2023.2250784","url":null,"abstract":"The influence of bogie fairing on the flow feature and aerodynamic noise performance of a high-speed train nose car model is studied based on large-eddy simulation combined with acoustic analogy approach. For the case having no fairing, the strong flow interactions and impingements occur around the bogie cavity region due to the mass addition and expulsion induced from the cavity leading edges. When a streamlined fairing is mounted outside the bogie cavity, the fluid entrainment and vortices evolvement within the bogie cavity are weakened and the shear layer impingement and flow separation outside the fairing are mitigated greatly. Thus the wall pressure fluctuations on the solid surfaces of geometries located within bogie cavity are decreased and the flow-induced noise is reduced noticeably. Based on the semi-anechoic wind tunnel measurements on a high-speed train nose car model without and with bogie fairing, it is found that the dominant sound source around bogie cavity moves from its central area to rear wall region and the aerodynamic noise is reduced effectively with a streamlined fairing mounted around the bogie cavity. The numerical predictions of aerodynamic noise are verified by the experimental measurements. The investigation would be beneficial for guiding the low-noise design and configuration optimization of a high-speed train bogie fairing.","PeriodicalId":48510,"journal":{"name":"International Journal of Rail Transportation","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135825973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-25DOI: 10.1080/23248378.2023.2228802
Wenbo Zhao, W. Qiang, Fei Yang, G. Jing, Yunlong Guo
{"title":"Data-driven ballast layer degradation identification and maintenance decision based on track geometry irregularities","authors":"Wenbo Zhao, W. Qiang, Fei Yang, G. Jing, Yunlong Guo","doi":"10.1080/23248378.2023.2228802","DOIUrl":"https://doi.org/10.1080/23248378.2023.2228802","url":null,"abstract":"","PeriodicalId":48510,"journal":{"name":"International Journal of Rail Transportation","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45390609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-21DOI: 10.1080/23248378.2023.2225787
Dionysia Varvarigou, D. Espès, Giacomo Bersano
{"title":"Orchestrator for ensuring interdependency between safety and cybersecurity in railway control systems","authors":"Dionysia Varvarigou, D. Espès, Giacomo Bersano","doi":"10.1080/23248378.2023.2225787","DOIUrl":"https://doi.org/10.1080/23248378.2023.2225787","url":null,"abstract":"","PeriodicalId":48510,"journal":{"name":"International Journal of Rail Transportation","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45657652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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