The brake system is a key component of a high-speed train, which suffers intense wheel-rail interactions caused by wheel polygonal wear (WPW) in realistic working conditions. To explore the dynamic characteristics of the disc brake systems with WPW, a rigid-flexible coupled vehicle dynamics model is proposed. The developed model systematically takes into account the flexible deformation of brake components and wheelsets, measured WPW and non-linear factors such as wheel-rail interaction, disc-pad friction and non-linear damping characteristics. It allows the dynamic behaviors of the vehicle brake system in service to be accurately and effectively revealed. The model is verified using line test data, and then the dynamic characteristics of disc brake systems with WPW are investigated in details. The results show that for vehicle speed below 80 km/h and depths of WPW below 0.04 mm, the effect of WPW on the vibration of the caliper is slight. However, as vehicle speed and wear depth continue to rise, the vibration of the caliper increases noticeably. Furthermore, the effects of vehicle speed and wear depth on brake disc vibration are more obvious, and increasing vehicle speed and wear depth will steadily deteriorate the vibration of the disc. Besides, the effect of WPW is particularly pronounced on the dynamic behavior of the brake units closer to the wheels. Overall, the influence of wheel polygon cannot be neglected in the study of dynamic characteristics of brake system. At the same time, the proposed model can also be applied in the strength evaluation of brake components and the study of the tribological behaviors within the brake interface.
制动系统是高速列车的关键部件，在实际工况下，由于车轮多边形磨损（WPW），制动系统会受到强烈的轮轨相互作用。为了探索具有 WPW 的盘式制动系统的动态特性，提出了一种刚柔耦合车辆动力学模型。所开发的模型系统地考虑了制动部件和轮组的柔性变形、测量的 WPW 和非线性因素，如轮轨相互作用、盘垫摩擦和非线性阻尼特性。它能准确有效地揭示车辆制动系统在使用中的动态行为。利用线路测试数据对模型进行了验证，然后详细研究了带 WPW 的盘式制动系统的动态特性。结果表明，当车速低于 80 km/h 和磨损深度低于 0.04 mm 时，可变厚度对制动钳振动的影响很小。然而，随着车速和磨损深度的不断增加，卡钳的振动明显增加。此外，车速和磨损深度对制动盘振动的影响更为明显，车速和磨损深度的增加会使制动盘的振动持续恶化。此外，加宽轮距对靠近车轮的制动单元的动态特性影响尤为明显。总之，在制动系统动态特性研究中，车轮多边形的影响不容忽视。同时，所提出的模型还可用于制动部件的强度评估和制动界面内摩擦学行为的研究。
{"title":"Dynamic characteristics of disc brake systems of a high-speed train with wheel polygonal wear","authors":"Linchuan Yang, Huaqian Zhang, Peng Zhao, Zhiwei Wang, Chunguang Zhao, Jiliang Mo","doi":"10.1177/09544097241264322","DOIUrl":"https://doi.org/10.1177/09544097241264322","url":null,"abstract":"The brake system is a key component of a high-speed train, which suffers intense wheel-rail interactions caused by wheel polygonal wear (WPW) in realistic working conditions. To explore the dynamic characteristics of the disc brake systems with WPW, a rigid-flexible coupled vehicle dynamics model is proposed. The developed model systematically takes into account the flexible deformation of brake components and wheelsets, measured WPW and non-linear factors such as wheel-rail interaction, disc-pad friction and non-linear damping characteristics. It allows the dynamic behaviors of the vehicle brake system in service to be accurately and effectively revealed. The model is verified using line test data, and then the dynamic characteristics of disc brake systems with WPW are investigated in details. The results show that for vehicle speed below 80 km/h and depths of WPW below 0.04 mm, the effect of WPW on the vibration of the caliper is slight. However, as vehicle speed and wear depth continue to rise, the vibration of the caliper increases noticeably. Furthermore, the effects of vehicle speed and wear depth on brake disc vibration are more obvious, and increasing vehicle speed and wear depth will steadily deteriorate the vibration of the disc. Besides, the effect of WPW is particularly pronounced on the dynamic behavior of the brake units closer to the wheels. Overall, the influence of wheel polygon cannot be neglected in the study of dynamic characteristics of brake system. At the same time, the proposed model can also be applied in the strength evaluation of brake components and the study of the tribological behaviors within the brake interface.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141505375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-06-21DOI: 10.1177/09544097241262360
Jing He, Weiqi Wang, Quan Zhang, Wenkun Wang, Nengpu Yang
Rail corrugation is a common form of rail damage discovered when servicing heavy-haul railways that seriously affects the safety of wheel–rail systems. To determine the characteristics of the deterioration of a corrugated heavy-haul railway, this study used ABAQUS simulation software to establish a three-dimensional elastic–plastic wheel–rail finite element model. We then simulated the stress and strain distributions of wheel–rail contact spots as C80 freight cars pass through various corrugated sections of heavy-haul railways, featuring different wavelengths and wave depths. The simulation results demonstrated that the stress and strain increase from the peak positions to the troughs, reaching a maximum somewhere behind the troughs, and then decreasing to the next peak. The stress and strain increase as the depth of corrugation increases. The wheel–rail contact exhibits a maximum stress of 1.312 to 1.770 GPa, and the maximum strain is 0.6470% to 0.9897%. Wheel–rail contact stress and strain occur at a maximum of 8–40 mm after the troughs, rather than at the trough position, forming “planing and rolling” effects. This mechanism revealed by the variation in the stress and strain distributions in this study provides a reference for the in-depth analysis of rail corrugation deterioration and for the exploration of the mechanisms of corrugation deterioration of heavy-haul railways.
{"title":"Analysis of rail corrugation deterioration behavior on a heavy-haul railway","authors":"Jing He, Weiqi Wang, Quan Zhang, Wenkun Wang, Nengpu Yang","doi":"10.1177/09544097241262360","DOIUrl":"https://doi.org/10.1177/09544097241262360","url":null,"abstract":"Rail corrugation is a common form of rail damage discovered when servicing heavy-haul railways that seriously affects the safety of wheel–rail systems. To determine the characteristics of the deterioration of a corrugated heavy-haul railway, this study used ABAQUS simulation software to establish a three-dimensional elastic–plastic wheel–rail finite element model. We then simulated the stress and strain distributions of wheel–rail contact spots as C80 freight cars pass through various corrugated sections of heavy-haul railways, featuring different wavelengths and wave depths. The simulation results demonstrated that the stress and strain increase from the peak positions to the troughs, reaching a maximum somewhere behind the troughs, and then decreasing to the next peak. The stress and strain increase as the depth of corrugation increases. The wheel–rail contact exhibits a maximum stress of 1.312 to 1.770 GPa, and the maximum strain is 0.6470% to 0.9897%. Wheel–rail contact stress and strain occur at a maximum of 8–40 mm after the troughs, rather than at the trough position, forming “planing and rolling” effects. This mechanism revealed by the variation in the stress and strain distributions in this study provides a reference for the in-depth analysis of rail corrugation deterioration and for the exploration of the mechanisms of corrugation deterioration of heavy-haul railways.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141505374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-05-30DOI: 10.1177/09544097241257551
Shuguo Wang, Jingmang Xu, Caiwei Liu, Yao Qian, Ping Wang, Pu Wang, Qiantao Ma, Boyi Liu
In order to effectively address the engineering problem of optimizing the worn rail profile on subway sharp-radius curves, this paper focuses on the inconsistent wear characteristics of rails on such curves. The contact stress, wheel-rail lateral force, and wear index are taken as objective functions, and key rail profiles at the points of straight-transition, transition-curve, curve-midpoint, circular-transition, and transition-straight are selected. A multi-objective and multi-section optimization scheme based on the optimized limit curve is proposed to design the grinding profile for rails on subway sharp-radius curves. In order to compare its optimization effectiveness, two additional optimization schemes are presented: the second scheme involves multi-section profile optimization with no optimized limit curve as constraints, and the third scheme deals with optimizing a single profile for grinding with equal cross-sections. Through a comparison of the three optimization schemes, the results indicate that all three schemes lead to a reduction in the contact stress, wheel-rail lateral force, and wear index of the outer and inner stock rails after optimization. Scheme 1 shows a more extensive and uniform distribution of wheel-rail contact points, with larger reductions in contact stress and increases in contact area. Scheme 3 only improves contact in severely worn sections, while in less worn sections, the contact distribution becomes concentrated, accelerating wear evolution. Furthermore, in Scheme 1, the cumulative wear after 100,000 and 200,000 cycles is reduced by a maximum of 8.44% and 22.33% compared to before optimization, making it the most effective among the three schemes. Therefore, the optimized profile output by the optimization method proposed in this paper is considered the best solution, which is represented by Scheme 1.
{"title":"Rail profile optimization of a subway’s sharp curve considering multiple curve sections and metal removal","authors":"Shuguo Wang, Jingmang Xu, Caiwei Liu, Yao Qian, Ping Wang, Pu Wang, Qiantao Ma, Boyi Liu","doi":"10.1177/09544097241257551","DOIUrl":"https://doi.org/10.1177/09544097241257551","url":null,"abstract":"In order to effectively address the engineering problem of optimizing the worn rail profile on subway sharp-radius curves, this paper focuses on the inconsistent wear characteristics of rails on such curves. The contact stress, wheel-rail lateral force, and wear index are taken as objective functions, and key rail profiles at the points of straight-transition, transition-curve, curve-midpoint, circular-transition, and transition-straight are selected. A multi-objective and multi-section optimization scheme based on the optimized limit curve is proposed to design the grinding profile for rails on subway sharp-radius curves. In order to compare its optimization effectiveness, two additional optimization schemes are presented: the second scheme involves multi-section profile optimization with no optimized limit curve as constraints, and the third scheme deals with optimizing a single profile for grinding with equal cross-sections. Through a comparison of the three optimization schemes, the results indicate that all three schemes lead to a reduction in the contact stress, wheel-rail lateral force, and wear index of the outer and inner stock rails after optimization. Scheme 1 shows a more extensive and uniform distribution of wheel-rail contact points, with larger reductions in contact stress and increases in contact area. Scheme 3 only improves contact in severely worn sections, while in less worn sections, the contact distribution becomes concentrated, accelerating wear evolution. Furthermore, in Scheme 1, the cumulative wear after 100,000 and 200,000 cycles is reduced by a maximum of 8.44% and 22.33% compared to before optimization, making it the most effective among the three schemes. Therefore, the optimized profile output by the optimization method proposed in this paper is considered the best solution, which is represented by Scheme 1.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141196888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper aims to create a friction coupling finite element model of the wheelset–track system, taking into account various curve radii and corresponding wheel/rail contact states. This model will serve as a tool to analyze the underlying causes of curve squeal phenomena. Furthermore, we conducted an investigation into the impact of rail and wheel wear on system stability. This paper utilized a complex eigenvalue analysis (CEA) method to accurately calculate and predict vibration instabilities in the system. The results show that the smaller the radius of the curve, the more prone to it is lateral creep between the rail and the leading wheelset, so that the system is more prone to self-excited frictional vibrations, ultimately resulting in the generation of curve squeal. In addition, the wear of the wheel tread/rail head increases the instability of the system. When the train passes through a section with rail corrugation, rail corrugation suppresses the occurrence of curve squeal.
{"title":"Study on the generation mechanism of curve squeal and its relationship with wheel/rail wear","authors":"Xiaohang Feng, Guangxiong Chen, Bingjie Dong, Qifeng Song, Wenjuan Ren","doi":"10.1177/09544097241257290","DOIUrl":"https://doi.org/10.1177/09544097241257290","url":null,"abstract":"This paper aims to create a friction coupling finite element model of the wheelset–track system, taking into account various curve radii and corresponding wheel/rail contact states. This model will serve as a tool to analyze the underlying causes of curve squeal phenomena. Furthermore, we conducted an investigation into the impact of rail and wheel wear on system stability. This paper utilized a complex eigenvalue analysis (CEA) method to accurately calculate and predict vibration instabilities in the system. The results show that the smaller the radius of the curve, the more prone to it is lateral creep between the rail and the leading wheelset, so that the system is more prone to self-excited frictional vibrations, ultimately resulting in the generation of curve squeal. In addition, the wear of the wheel tread/rail head increases the instability of the system. When the train passes through a section with rail corrugation, rail corrugation suppresses the occurrence of curve squeal.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141196754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-05-29DOI: 10.1177/09544097241257550
Gioele Isacchi, Francesco Ripamonti
In recent years, huge investments have been made to improve the dynamic performance of high-speed trains. Research into innovative suspension components has been part of the development of this transport system for decades. Innovative devices can allow rail vehicles to deal with the constantly increasing speed required by the global market. Among the most innovative suspension layouts proposed in railway dynamics in past years, limited attention has been given to Hydraulic Interconnected Suspensions (HIS). This layout is composed of two hydraulic cylinders with external hydraulic connections. Hydraulic Interconnected Suspensions allow promising tuning capabilities due to their ability to offer different responses based on the specific inputs given to the cylinders. This layout is rarely considered for rail vehicles, and the few previous works related to this topic considered the HIS layout to be applied at the secondary suspension stage. In this context, this paper proposes applying an HIS layout to the primary suspension stage of rail vehicles, in order to overcome the trade-offs between ride comfort, running safety and maximum car body displacement that need to be considered by bogie manufacturers when designing and optimising these mechanical systems. A nonlinear physical model of the HIS is proposed for co-simulation with a Multi-body (MB) model of a high-speed train. The improvement provided implementing an HIS at the primary suspension stage is then compared to similar enhancements that could be made when tuning and varying the standard suspension components of a bogie.
近年来，为提高高速列车的动态性能，投入了大量资金。几十年来，对创新悬挂部件的研究一直是这一运输系统发展的一部分。创新装置可使轨道车辆满足全球市场不断提高的速度要求。在过去几年铁路动力学领域提出的最具创新性的悬挂布局中，液压互联悬挂系统（HIS）受到的关注有限。这种布局由两个带外部液压连接的液压缸组成。由于液压互联悬挂系统能够根据给油缸的特定输入提供不同的响应，因此具有很强的调整能力。轨道车辆很少考虑这种布局，而且之前与此主题相关的少数几项工作都考虑将 HIS 布局应用于二级悬挂阶段。在这种情况下，本文建议将 HIS 布局应用于轨道车辆的一级悬挂阶段，以克服转向架制造商在设计和优化这些机械系统时需要考虑的乘坐舒适性、运行安全性和最大车体位移之间的权衡问题。我们提出了 HIS 的非线性物理模型，用于与高速列车的多体 (MB) 模型进行联合模拟。然后，将在主悬挂阶段实施 HIS 所带来的改进与调整和改变转向架标准悬挂部件所带来的类似改进进行比较。
{"title":"On the implementation of hydraulic-interconnected-suspensions at the primary suspension stage of high-speed rail vehicles","authors":"Gioele Isacchi, Francesco Ripamonti","doi":"10.1177/09544097241257550","DOIUrl":"https://doi.org/10.1177/09544097241257550","url":null,"abstract":"In recent years, huge investments have been made to improve the dynamic performance of high-speed trains. Research into innovative suspension components has been part of the development of this transport system for decades. Innovative devices can allow rail vehicles to deal with the constantly increasing speed required by the global market. Among the most innovative suspension layouts proposed in railway dynamics in past years, limited attention has been given to Hydraulic Interconnected Suspensions (HIS). This layout is composed of two hydraulic cylinders with external hydraulic connections. Hydraulic Interconnected Suspensions allow promising tuning capabilities due to their ability to offer different responses based on the specific inputs given to the cylinders. This layout is rarely considered for rail vehicles, and the few previous works related to this topic considered the HIS layout to be applied at the secondary suspension stage. In this context, this paper proposes applying an HIS layout to the primary suspension stage of rail vehicles, in order to overcome the trade-offs between ride comfort, running safety and maximum car body displacement that need to be considered by bogie manufacturers when designing and optimising these mechanical systems. A nonlinear physical model of the HIS is proposed for co-simulation with a Multi-body (MB) model of a high-speed train. The improvement provided implementing an HIS at the primary suspension stage is then compared to similar enhancements that could be made when tuning and varying the standard suspension components of a bogie.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141196753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-05-11DOI: 10.1177/09544097241241356
Jun Wang, Mohammad Siahkouhi, Yunchang Du, Gang Huang, Xiaodong Han, Guoqing Jing
This paper explores the use of three waste materials available in vast quantities, including waste tires, glass bottles and bamboo furniture, in the manufacture of railway sleepers. Mechanical properties of recycled concrete have been studied to establish an optimal mix suitable for concrete railway sleeper manufacturing. Thus, 5%, 10%, 15% and 20% recycled rubber sands (RRS) by volume of fine aggregate are used instead of 30# and 60# mesh sizes of fine aggregate. Moreover, 20%, 40%, 60%, 80% and 100% of aggregate volume are replaced by recycled glass aggregate (RGA) particles. Furthermore, different percentages of recycled bamboo fibers (RBF) have been used as 1%, 2% and 3% by volume of concrete. According to the optimal concrete mixtures of RRS, RGA and RBF, twelve concrete railway sleepers are manufactured and tested for middle and rail seat bending strengths. Results show that ref. sleeper has almost 16% and 24% lower strengths than RGA sleeper in middle and rail seat, respectively, while ref. sleeper have higher strengths by 16% and 13%, and 18% and 7% than RRS sleeper (M60-R5) and RBF sleeper (B2) in middle and rail seat, respectively. The FEM results show that the ([Formula: see text]) of the RGA sleeper is the minimum ratio by 1.11 and 1.13 for rail seat and middle of sleeper, respectively, which is the best performance. In RBF sleeper FEM model, Bamboo fiber can only bear 5% and 8% of total stress in middle and rail seat, respectively, due to low mechanical properties of fibers.
{"title":"Improving the mechanical performance of railway concrete sleepers using recycled materials: An experimental and numerical study","authors":"Jun Wang, Mohammad Siahkouhi, Yunchang Du, Gang Huang, Xiaodong Han, Guoqing Jing","doi":"10.1177/09544097241241356","DOIUrl":"https://doi.org/10.1177/09544097241241356","url":null,"abstract":"This paper explores the use of three waste materials available in vast quantities, including waste tires, glass bottles and bamboo furniture, in the manufacture of railway sleepers. Mechanical properties of recycled concrete have been studied to establish an optimal mix suitable for concrete railway sleeper manufacturing. Thus, 5%, 10%, 15% and 20% recycled rubber sands (RRS) by volume of fine aggregate are used instead of 30# and 60# mesh sizes of fine aggregate. Moreover, 20%, 40%, 60%, 80% and 100% of aggregate volume are replaced by recycled glass aggregate (RGA) particles. Furthermore, different percentages of recycled bamboo fibers (RBF) have been used as 1%, 2% and 3% by volume of concrete. According to the optimal concrete mixtures of RRS, RGA and RBF, twelve concrete railway sleepers are manufactured and tested for middle and rail seat bending strengths. Results show that ref. sleeper has almost 16% and 24% lower strengths than RGA sleeper in middle and rail seat, respectively, while ref. sleeper have higher strengths by 16% and 13%, and 18% and 7% than RRS sleeper (M60-R5) and RBF sleeper (B2) in middle and rail seat, respectively. The FEM results show that the ([Formula: see text]) of the RGA sleeper is the minimum ratio by 1.11 and 1.13 for rail seat and middle of sleeper, respectively, which is the best performance. In RBF sleeper FEM model, Bamboo fiber can only bear 5% and 8% of total stress in middle and rail seat, respectively, due to low mechanical properties of fibers.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140934373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
With the increase in running speed, the aerodynamic characteristics of high-speed trains have a significant impact on running stability, energy consumption and passenger comfort. Since the shape of the high-speed train head can directly influence the surrounding airflow, optimizing the head shape is the primary way to improve the aerodynamic performance of the train. This paper reviews current research studies on the surrogate-based aerodynamic shape optimization of high-speed train heads, aiming to provide a comprehensive reference for designers to enhance design efficiency and optimization performance. The entire optimization process is divided into four essential steps, and the key optimization technologies in each step are discussed, including parametric modeling, computational fluid dynamics (CFD) simulation, surrogate model and optimization algorithm. By introducing the practical applications of these technologies, we summarize their advantages and disadvantages and suggest four potential research directions for the future.
{"title":"Surrogate-based aerodynamic shape optimization of high-speed train heads: A review of four key technologies","authors":"Hongbo Wang, Shuangbu Wang, Dayuan Zhuang, Zaiping Zhu, Pengcheng You, Zhao Tang, Guofu Ding","doi":"10.1177/09544097241251509","DOIUrl":"https://doi.org/10.1177/09544097241251509","url":null,"abstract":"With the increase in running speed, the aerodynamic characteristics of high-speed trains have a significant impact on running stability, energy consumption and passenger comfort. Since the shape of the high-speed train head can directly influence the surrounding airflow, optimizing the head shape is the primary way to improve the aerodynamic performance of the train. This paper reviews current research studies on the surrogate-based aerodynamic shape optimization of high-speed train heads, aiming to provide a comprehensive reference for designers to enhance design efficiency and optimization performance. The entire optimization process is divided into four essential steps, and the key optimization technologies in each step are discussed, including parametric modeling, computational fluid dynamics (CFD) simulation, surrogate model and optimization algorithm. By introducing the practical applications of these technologies, we summarize their advantages and disadvantages and suggest four potential research directions for the future.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140885787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-05-06DOI: 10.1177/09544097241248205
Pengfei Liu, Kai Hao, Chen Wang, Meiqi Wang, Ao Wang, Zida Xing
To determine the minimum and reasonable radius of horizontal curve for reducing wheel wear in heavy-haul railway design, a HXD locomotive with the wheel arrangement of C0-C0 is taken as the research object. Both the corresponding locomotive dynamic model and wheel wear model are established. Based on the measured wear data in a specific line, the simulation model is verified with the prediction error of wheel wear depth below 0.5 mm in general. The wheel wear evolution rules in 400∼1000m radius curves are studied and compared. The results indicate that, the wheel wear is large and sensitive to curve radius within 400∼600 m. The larger radius curve will be helpful to reduce wheel flange contact and wheel wear. For curve radius increasing from 600m to 1000m, the wheel average wear reduces slowly. Especially for curve radius below around 740 m, the wheel flange wear will be predominant. For radius above 740m, the wheel tread wear becomes the main wear form and the wheel flange wear can be reduced significantly. The increase of curve radius will also improve the wheel-rail equivalent conicity. If the minimum curve radius is set as 800m, the equivalent conicity difference between new wheelset and 1st ∼ 3rd worn wheelset can be kept below 21%, 52% and 9% respectively. In this case, the equivalent conicity is closest to the initial state and reaches a steady state, which will not change significantly with the radius further increasing. Viewed from the aspects of reducing wheel wear, avoiding wheel flange contact and keeping conicity stable simultaneously, the minimum radius of horizontal curve should be limited to 800 m. The research results validate the minimum curve radius suggested in Code for Design of Heavy-haul Railway in China, and provide a scientific explanation for the determination of this value.
{"title":"Investigation of curve minimum radius in heavy-haul railway to improve wheel wear evolution and wheel-rail contact geometry","authors":"Pengfei Liu, Kai Hao, Chen Wang, Meiqi Wang, Ao Wang, Zida Xing","doi":"10.1177/09544097241248205","DOIUrl":"https://doi.org/10.1177/09544097241248205","url":null,"abstract":"To determine the minimum and reasonable radius of horizontal curve for reducing wheel wear in heavy-haul railway design, a HXD locomotive with the wheel arrangement of C0-C0 is taken as the research object. Both the corresponding locomotive dynamic model and wheel wear model are established. Based on the measured wear data in a specific line, the simulation model is verified with the prediction error of wheel wear depth below 0.5 mm in general. The wheel wear evolution rules in 400∼1000m radius curves are studied and compared. The results indicate that, the wheel wear is large and sensitive to curve radius within 400∼600 m. The larger radius curve will be helpful to reduce wheel flange contact and wheel wear. For curve radius increasing from 600m to 1000m, the wheel average wear reduces slowly. Especially for curve radius below around 740 m, the wheel flange wear will be predominant. For radius above 740m, the wheel tread wear becomes the main wear form and the wheel flange wear can be reduced significantly. The increase of curve radius will also improve the wheel-rail equivalent conicity. If the minimum curve radius is set as 800m, the equivalent conicity difference between new wheelset and 1st ∼ 3rd worn wheelset can be kept below 21%, 52% and 9% respectively. In this case, the equivalent conicity is closest to the initial state and reaches a steady state, which will not change significantly with the radius further increasing. Viewed from the aspects of reducing wheel wear, avoiding wheel flange contact and keeping conicity stable simultaneously, the minimum radius of horizontal curve should be limited to 800 m. The research results validate the minimum curve radius suggested in Code for Design of Heavy-haul Railway in China, and provide a scientific explanation for the determination of this value.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140885905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effect of aerodynamic noise from high-speed trains on residents living near railway lines is a critical issue. The pantograph cavity is considered to be a major source of aerodynamic noise. To address this problem, this study proposes the application of jetting at the leading edge of the cavity, directly targeting noise reduction at its source. The large eddy simulation approach is used for flow calculations, and the Ffowcs Williams and Hawkings aeroacoustic analogy is adopted for far-field acoustic predictions. Orthogonal designs and the backpropagation algorithm optimized by the genetic algorithm (BP-GA) is used to explore the effects of jetting factors on noise and identify the optimal parameters. Orthogonal design analysis shows that the most influential among the factors is jet orifice diameter, followed by jet velocity and jet angle. The use of the BP-GA algorithm for optimization reveals that the optimal jet parameters are jet velocity of 118.28 m/s, jet angle of 3.17°, and jet orifice diameter of 76.74 mm. The algorithm predicts a minimum noise level of 91.04 dB, which is close to the simulated noise level of 90.74 dB. The jetting process achieves a maximum noise reduction of 4 dB. Results demonstrate that the proposed method for cavity leading edge jetting effectively reduces turbulent kinetic energy and horseshoe-shaped vortices in the cavity, leading to noise reduction. This method also minimizes the effects of aerodynamic noise on distant areas, such as waiting areas and residential buildings. This work provides a theoretical basis for increasing high-speed train speeds.
{"title":"Cavity noise reduction of a high-speed train pantograph through jet parameter optimization","authors":"Ziheng Zhang, Xiaodan Miao, Daowei Liu, Ruigang Song, Tianchen Yuan, Jian Yang","doi":"10.1177/09544097241251912","DOIUrl":"https://doi.org/10.1177/09544097241251912","url":null,"abstract":"The effect of aerodynamic noise from high-speed trains on residents living near railway lines is a critical issue. The pantograph cavity is considered to be a major source of aerodynamic noise. To address this problem, this study proposes the application of jetting at the leading edge of the cavity, directly targeting noise reduction at its source. The large eddy simulation approach is used for flow calculations, and the Ffowcs Williams and Hawkings aeroacoustic analogy is adopted for far-field acoustic predictions. Orthogonal designs and the backpropagation algorithm optimized by the genetic algorithm (BP-GA) is used to explore the effects of jetting factors on noise and identify the optimal parameters. Orthogonal design analysis shows that the most influential among the factors is jet orifice diameter, followed by jet velocity and jet angle. The use of the BP-GA algorithm for optimization reveals that the optimal jet parameters are jet velocity of 118.28 m/s, jet angle of 3.17°, and jet orifice diameter of 76.74 mm. The algorithm predicts a minimum noise level of 91.04 dB, which is close to the simulated noise level of 90.74 dB. The jetting process achieves a maximum noise reduction of 4 dB. Results demonstrate that the proposed method for cavity leading edge jetting effectively reduces turbulent kinetic energy and horseshoe-shaped vortices in the cavity, leading to noise reduction. This method also minimizes the effects of aerodynamic noise on distant areas, such as waiting areas and residential buildings. This work provides a theoretical basis for increasing high-speed train speeds.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140885907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-04-29DOI: 10.1177/09544097241245150
Pedro Museros, Andreas Andersson, Benjamín Pinazo
In the field of structural analysis dedicated to the study of vibrations of high-speed railway bridges, one reference load model is the well-known HSLM-A, which limits of validity are stated in Eurocode EN 1991-2, Annex E. In a recent paper published in the Journal of Rail and Rapid Transit, the authors investigated the degree of coverage provided by HSLM-A to critical articulated trains. Now in the present article, the authors have extended those analyses to critical conventional and regular trains as well. This is an important aspect because HSLM-A as such is an articulated-type model, so it is of interest to understand how it deals with covering the various resonance phenomena generated by other train types. Therefore, the main goal of this work is to establish whether the conventional and regular trains that stem from the validity rules given in Annex E/EN 1991-2, produce vibratory effects that are duly covered by HSLM-A. Following the aforementioned validity rules, one first aspect analysed is the importance of near-to-integer wheelbase ratios in the coupled vibrations produced by conventional trains. Subsequently, seven realistic, conventional and regular high-speed train models have been synthesised; these models have been made publicly available in Mendeley Data, and comprise almost 3800 different sequences of axle loads. Finally, the response of simply-supported bridges has been analysed with a view to compare the seven synthesised models versus HSLM-A. The exceedance and required speed increase have been computed for both displacements and accelerations, in a comprehensive ensemble of spans and speeds. The results provide a diagnosis of the degree of coverage of HSLM-A with respect to those conventional and regular trains compliant with Annex E/EN 1991-2.
{"title":"Dynamic behaviour of bridges under critical conventional and regular trains: Review of some regulations included in EN 1991-2","authors":"Pedro Museros, Andreas Andersson, Benjamín Pinazo","doi":"10.1177/09544097241245150","DOIUrl":"https://doi.org/10.1177/09544097241245150","url":null,"abstract":"In the field of structural analysis dedicated to the study of vibrations of high-speed railway bridges, one reference load model is the well-known HSLM-A, which limits of validity are stated in Eurocode EN 1991-2, Annex E. In a recent paper published in the Journal of Rail and Rapid Transit, the authors investigated the degree of coverage provided by HSLM-A to critical articulated trains. Now in the present article, the authors have extended those analyses to critical conventional and regular trains as well. This is an important aspect because HSLM-A as such is an articulated-type model, so it is of interest to understand how it deals with covering the various resonance phenomena generated by other train types. Therefore, the main goal of this work is to establish whether the conventional and regular trains that stem from the validity rules given in Annex E/EN 1991-2, produce vibratory effects that are duly covered by HSLM-A. Following the aforementioned validity rules, one first aspect analysed is the importance of near-to-integer wheelbase ratios in the coupled vibrations produced by conventional trains. Subsequently, seven realistic, conventional and regular high-speed train models have been synthesised; these models have been made publicly available in Mendeley Data, and comprise almost 3800 different sequences of axle loads. Finally, the response of simply-supported bridges has been analysed with a view to compare the seven synthesised models versus HSLM-A. The exceedance and required speed increase have been computed for both displacements and accelerations, in a comprehensive ensemble of spans and speeds. The results provide a diagnosis of the degree of coverage of HSLM-A with respect to those conventional and regular trains compliant with Annex E/EN 1991-2.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140826821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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