Pub Date : 2023-06-28DOI: 10.1177/09544097231184586
S. Vishnu, Shaswat Garg, S.P. Singh, SK Saha
In this work, we have developed a serial-chain multibody model of a rail vehicle, using the Decoupled Natural Orthogonal Complement matrices. The governing equations of the system were linearized, and the start of hunting was identified by finding the Smallest Bifurcation Point (SBP) of the trivial solution. Uneven wear creates differences in the properties of similar components in a rail vehicle. It was found that such variations are neglected in the hunting analysis. Hence, we introduce these differences by independently changing 32 parameters. The study found that these variations lead to unique trends. Then, these trends were used to recommend design changes for a rail vehicle, which could be thought of, in order to improve the hunting characteristics. For this purpose, an interactive software tool was created to easily visualize, and manipulate the hunting behavior of a rail vehicle.
{"title":"Differential parametrization of rail vehicle properties and its impact on hunting","authors":"S. Vishnu, Shaswat Garg, S.P. Singh, SK Saha","doi":"10.1177/09544097231184586","DOIUrl":"https://doi.org/10.1177/09544097231184586","url":null,"abstract":"In this work, we have developed a serial-chain multibody model of a rail vehicle, using the Decoupled Natural Orthogonal Complement matrices. The governing equations of the system were linearized, and the start of hunting was identified by finding the Smallest Bifurcation Point (SBP) of the trivial solution. Uneven wear creates differences in the properties of similar components in a rail vehicle. It was found that such variations are neglected in the hunting analysis. Hence, we introduce these differences by independently changing 32 parameters. The study found that these variations lead to unique trends. Then, these trends were used to recommend design changes for a rail vehicle, which could be thought of, in order to improve the hunting characteristics. For this purpose, an interactive software tool was created to easily visualize, and manipulate the hunting behavior of a rail vehicle.","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":"2023-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87074211","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 : 2023-06-28DOI: 10.1177/09544097231185800
J. Rebelo, P. Antunes, J. Ambrósio, J. Pombo
Currently, the modelling of the railway catenaries for straight tracks is well understood and demonstrated via an accepted number of applications and an international benchmark. However, in the presence of a general track geometry, including curved tracks, challenges still remain. The fundamental difficulty is how to address the catenary layout in the presence of curves for a long railway track in which a large number of catenary sections are defined. To support the catenary design, e.g. in new electrification projects, it is fundamental to identify the track geometry, which is not always accessible to the overhead line engineers. This work purposes a novel approach for track geometry reconstruction using aerial views. The reconstruction methodology is based on the general geometry rules for track design. The track geometry obtained is then used as the reference to define the layout of the catenary. The Network Rail Series 1 overhead equipment is used here and the 3D finite element model of the catenary is built on the curved track geometry. The results of this work demonstrate, not only the advances proposed to study more realistically the pantograph-catenary interaction, but also the need to consider general curved tracks in acceptance and interoperability studies.
目前，直线轨道的铁路悬架的建模已经得到了很好的理解，并通过一些公认的应用程序和国际基准进行了演示。然而，在一般轨道几何形状(包括弯曲轨道)存在的情况下，挑战仍然存在。对于具有大量接触网段的长轨道，如何解决存在曲线时的接触网布置问题是最根本的困难。为了支持悬链线设计，例如在新的电气化项目中，确定轨道几何形状是至关重要的，而架空线路工程师并不总是能够获得这些几何形状。这项工作的目的是利用鸟瞰图重建轨道几何形状的新方法。重建方法是基于轨道设计的一般几何规则。然后将得到的轨迹几何形状作为参考来定义悬链线的布局。本文采用Network Rail Series 1架空设备，在曲线轨道几何上建立接触网的三维有限元模型。这项工作的结果不仅表明了更现实地研究受电弓-接触网相互作用的进展，而且表明了在接受和互操作性研究中考虑一般弯曲轨道的必要性。
{"title":"Track and catenary reconstruction from aerial images for the realistic analysis of rail electrification systems","authors":"J. Rebelo, P. Antunes, J. Ambrósio, J. Pombo","doi":"10.1177/09544097231185800","DOIUrl":"https://doi.org/10.1177/09544097231185800","url":null,"abstract":"Currently, the modelling of the railway catenaries for straight tracks is well understood and demonstrated via an accepted number of applications and an international benchmark. However, in the presence of a general track geometry, including curved tracks, challenges still remain. The fundamental difficulty is how to address the catenary layout in the presence of curves for a long railway track in which a large number of catenary sections are defined. To support the catenary design, e.g. in new electrification projects, it is fundamental to identify the track geometry, which is not always accessible to the overhead line engineers. This work purposes a novel approach for track geometry reconstruction using aerial views. The reconstruction methodology is based on the general geometry rules for track design. The track geometry obtained is then used as the reference to define the layout of the catenary. The Network Rail Series 1 overhead equipment is used here and the 3D finite element model of the catenary is built on the curved track geometry. The results of this work demonstrate, not only the advances proposed to study more realistically the pantograph-catenary interaction, but also the need to consider general curved tracks in acceptance and interoperability studies.","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":"2023-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74967896","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 : 2023-06-27DOI: 10.1177/09544097231184000
P. Cuervo, A. Toro, J. Meza, JF Santa, R. Lewis
The tribological behavior of wheel and rail material twin-disc samples prepared under laboratory-controlled grinding operations was studied. A laboratory grinding device was designed and validated to produce similar results to those found in the field in terms of surface quality and presence of white etching layer (WEL). The test samples were evaluated in a twin-disc machine under dry and lubricated conditions. The results showed that the surface finishing parameters and the microstructure change greatly depending on the surface preparation procedure, and that such changes affect the tribological response of the samples. The wear rates of the tribological tests for the different rail surface qualities showed a reduction of 47.4% for the lubricated tests and 7.3% for the dry tests when the surfaces of the rail specimens were finished by grinding. This is only applied when the WEL thickness was less than 4 μm.
{"title":"A twin-disc study of the role of the surface quality achieved by grinding on the wear resistance and rolling contact fatigue behavior of wheel/rail pairs","authors":"P. Cuervo, A. Toro, J. Meza, JF Santa, R. Lewis","doi":"10.1177/09544097231184000","DOIUrl":"https://doi.org/10.1177/09544097231184000","url":null,"abstract":"The tribological behavior of wheel and rail material twin-disc samples prepared under laboratory-controlled grinding operations was studied. A laboratory grinding device was designed and validated to produce similar results to those found in the field in terms of surface quality and presence of white etching layer (WEL). The test samples were evaluated in a twin-disc machine under dry and lubricated conditions. The results showed that the surface finishing parameters and the microstructure change greatly depending on the surface preparation procedure, and that such changes affect the tribological response of the samples. The wear rates of the tribological tests for the different rail surface qualities showed a reduction of 47.4% for the lubricated tests and 7.3% for the dry tests when the surfaces of the rail specimens were finished by grinding. This is only applied when the WEL thickness was less than 4 μm.","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":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86051667","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 : 2023-06-19DOI: 10.1177/09544097231182748
Dexiang Ren, G. Tao, Wei Li, Z. Wen
Short-pitch corrugation is a serious problem on resilient fastened railway track for many metro lines, causing severe noise and vibration that shortens the life of the vehicle and track components. To address this problem, the formation mechanism of this kind of corrugation is investigated in this study. The corrugation characteristics and natural frequency of the resilient fastener track are determined by field investigations. Then, ‘frequency sweeping’ and long-term rail-roughness prediction models are developed to reveal the crucial role of the interactions between two wheelsets in the corrugation formation and to estimate the effects of speed variations and bogie wheelbase on corrugation growth. The spectral analysis results indicate that the spatial frequency spectrum exhibits several peaks at equal intervals due to the short-pitch corrugation of a resilient fastener metro track, which are related to the third-order rail-bending vibration within the bogie wheelbase at about 775 Hz. In addition, large and small speed variations affect the wavelength and depth growth of the corrugation, respectively. The growth of corrugation depth is amplified when the resonance frequency associated with the corrugation formation is an integer-multiple of the wheel-passing frequency. The wheelbase is also an important factor in determining the corrugation wavelength because of its influence on the resonance frequency.
{"title":"Short-pitch corrugation formation on resilient fastener metro tracks explained using rail-bending vibrations within the bogie wheelbase","authors":"Dexiang Ren, G. Tao, Wei Li, Z. Wen","doi":"10.1177/09544097231182748","DOIUrl":"https://doi.org/10.1177/09544097231182748","url":null,"abstract":"Short-pitch corrugation is a serious problem on resilient fastened railway track for many metro lines, causing severe noise and vibration that shortens the life of the vehicle and track components. To address this problem, the formation mechanism of this kind of corrugation is investigated in this study. The corrugation characteristics and natural frequency of the resilient fastener track are determined by field investigations. Then, ‘frequency sweeping’ and long-term rail-roughness prediction models are developed to reveal the crucial role of the interactions between two wheelsets in the corrugation formation and to estimate the effects of speed variations and bogie wheelbase on corrugation growth. The spectral analysis results indicate that the spatial frequency spectrum exhibits several peaks at equal intervals due to the short-pitch corrugation of a resilient fastener metro track, which are related to the third-order rail-bending vibration within the bogie wheelbase at about 775 Hz. In addition, large and small speed variations affect the wavelength and depth growth of the corrugation, respectively. The growth of corrugation depth is amplified when the resonance frequency associated with the corrugation formation is an integer-multiple of the wheel-passing frequency. The wheelbase is also an important factor in determining the corrugation wavelength because of its influence on the resonance frequency.","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":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84477977","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 : 2023-06-17DOI: 10.1177/09544097231184735
M. Loidolt, Stefan Marschnig
Short wavelength rail defects or short-wave effects of rail have a significant influence on the system behaviour of railways. The influence of additional dynamic loads due to short-wave effects on component wear and the general quality behaviour of track is shown by several research papers. However, the described effect cannot yet be quantified comprehensively. This paper attempts to fill this gap. With the help of extensive data analysis, we can show that short-wave effects lead to a track geometry that is up to 50% worse than on average. Furthermore, we show examples illustrating the influence of untreated welded joints on the development of isolated defects of the track geometry. A detailed in-depth analysis of sections with different boundary conditions finally shows that short-wave effects have a significant influence on track geometry if the amplitude of the effect exceeds 0.15 mm. This value can be recommended as a threshold value in Austria and as a reference value in other countries.
{"title":"The impact of short-wave effects on deterioration of track geometry","authors":"M. Loidolt, Stefan Marschnig","doi":"10.1177/09544097231184735","DOIUrl":"https://doi.org/10.1177/09544097231184735","url":null,"abstract":"Short wavelength rail defects or short-wave effects of rail have a significant influence on the system behaviour of railways. The influence of additional dynamic loads due to short-wave effects on component wear and the general quality behaviour of track is shown by several research papers. However, the described effect cannot yet be quantified comprehensively. This paper attempts to fill this gap. With the help of extensive data analysis, we can show that short-wave effects lead to a track geometry that is up to 50% worse than on average. Furthermore, we show examples illustrating the influence of untreated welded joints on the development of isolated defects of the track geometry. A detailed in-depth analysis of sections with different boundary conditions finally shows that short-wave effects have a significant influence on track geometry if the amplitude of the effect exceeds 0.15 mm. This value can be recommended as a threshold value in Austria and as a reference value in other countries.","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":"2023-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81347336","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 : 2023-06-12DOI: 10.1177/09544097231183589
Y. Sun, M. Spiryagin, Qing Wu, C. Cole
Several models of a non-linear rail three-piece bogie container wagon have been developed by using GENSYS software to study the effects of the initial excitation conditions to the determination of rail wagon’s critical hunting speed and the trajectories and characteristics of the wheelset lateral movement during wagon hunting. The effect of uneven loading distribution on a container wagon to the wagon lateral instability is also investigated. Based on the simulation results, the wagon hunting is the type of bogie hunting, and the hunting behaviours are dependent on the initial excitation conditions and wagon speed. The initial excitation condition based on a certain initial lateral track irregularity can generate the full bogie hunting compared to the initial carbody’s lateral and yaw velocities that are the default widely used in the GENSYS setting. The two bogie lateral movement trajectories can have a phase of about 900 or be in-phase dependent on the wagon speed. The heavy loading on a bogie can improve the bogie hunting, and the uneven loading can change the hunting pattern.
{"title":"Lateral instability of three-piece bogie container wagon and effect of the loading distributions","authors":"Y. Sun, M. Spiryagin, Qing Wu, C. Cole","doi":"10.1177/09544097231183589","DOIUrl":"https://doi.org/10.1177/09544097231183589","url":null,"abstract":"Several models of a non-linear rail three-piece bogie container wagon have been developed by using GENSYS software to study the effects of the initial excitation conditions to the determination of rail wagon’s critical hunting speed and the trajectories and characteristics of the wheelset lateral movement during wagon hunting. The effect of uneven loading distribution on a container wagon to the wagon lateral instability is also investigated. Based on the simulation results, the wagon hunting is the type of bogie hunting, and the hunting behaviours are dependent on the initial excitation conditions and wagon speed. The initial excitation condition based on a certain initial lateral track irregularity can generate the full bogie hunting compared to the initial carbody’s lateral and yaw velocities that are the default widely used in the GENSYS setting. The two bogie lateral movement trajectories can have a phase of about 900 or be in-phase dependent on the wagon speed. The heavy loading on a bogie can improve the bogie hunting, and the uneven loading can change the hunting pattern.","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":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85222345","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 : 2023-06-08DOI: 10.1177/09544097231181301
M. Hou, Guang Yang, Bingzhi Chen, Fengshou Liu, Nashuyuan Wang
Small changes to wheel-rail profiles can have a significant impact on the equivalent conicity and vehicle dynamics. Previous research has focused mostly on worn wheels, however, with little attention to different types of rail profile deviation and their influences on vehicle dynamics. Therefore, the specific objective of this paper is to investigate the individual and combined influences of various rail profiles and multi-parameter couplings on the hunting instability of railway vehicles. This paper first obtains the distribution law of rail profile deviation from a statistical analysis of several rail profiles with long-term measurements. Then, the equivalent conicity of rail profiles that match the studied wheel profiles, gauges and wheelback distances is compared. The dynamic model for the vehicle has been established. Finally, the measured rail profiles and wheel profiles, as well as the combinations of the gauges, wheelback distances, friction coefficients and key suspension characteristics are integrated into the simulation model to analyze the atypical phenomenon of the carbody hunting and the bogie hunting. According to the findings, rail profile deviation has a significant impact on equivalent conicity and the evaluation of vehicle stability when subjected to multi-parameter coupling, particularly for worn wheels. Therefore, strict limits of rail profile deviation have to be considered in track maintenance for vehicles running at speeds of 300 km/h or higher.
{"title":"Investigating the effect of rail profile deviation on hunting instability of high-speed railway vehicle under multi-parameter coupling","authors":"M. Hou, Guang Yang, Bingzhi Chen, Fengshou Liu, Nashuyuan Wang","doi":"10.1177/09544097231181301","DOIUrl":"https://doi.org/10.1177/09544097231181301","url":null,"abstract":"Small changes to wheel-rail profiles can have a significant impact on the equivalent conicity and vehicle dynamics. Previous research has focused mostly on worn wheels, however, with little attention to different types of rail profile deviation and their influences on vehicle dynamics. Therefore, the specific objective of this paper is to investigate the individual and combined influences of various rail profiles and multi-parameter couplings on the hunting instability of railway vehicles. This paper first obtains the distribution law of rail profile deviation from a statistical analysis of several rail profiles with long-term measurements. Then, the equivalent conicity of rail profiles that match the studied wheel profiles, gauges and wheelback distances is compared. The dynamic model for the vehicle has been established. Finally, the measured rail profiles and wheel profiles, as well as the combinations of the gauges, wheelback distances, friction coefficients and key suspension characteristics are integrated into the simulation model to analyze the atypical phenomenon of the carbody hunting and the bogie hunting. According to the findings, rail profile deviation has a significant impact on equivalent conicity and the evaluation of vehicle stability when subjected to multi-parameter coupling, particularly for worn wheels. Therefore, strict limits of rail profile deviation have to be considered in track maintenance for vehicles running at speeds of 300 km/h or higher.","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":"2023-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73954104","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 : 2023-06-08DOI: 10.1177/09544097231178858
I. La Paglia, L. Rapino, F. Ripamonti, R. Corradi
Secondary suspensions play an essential role in the dynamic behaviour of rail vehicles. In particular, they are adopted to reduce the vibrations transmitted to the carbody, thus improving ride comfort. In this paper, an experimental characterization of the viscous damper and coil spring elements composing a vertical secondary suspension is presented. The elements are separately tested with the aim of analysing their dynamic behaviour. Then, modified prototypes are manufactured to reduce the transmitted force. The results of the experimental campaign are later adopted to tune the parameters of the mathematical model of the whole secondary suspension, including the dynamics of both the coil spring and the damper elements. This model allows discussing the effectiveness of the proposed modifications, proving the design of both the components to be fundamental for the improvement of ride comfort.
{"title":"Modelling and experimental characterization of secondary suspension elements for rail vehicle ride comfort simulation","authors":"I. La Paglia, L. Rapino, F. Ripamonti, R. Corradi","doi":"10.1177/09544097231178858","DOIUrl":"https://doi.org/10.1177/09544097231178858","url":null,"abstract":"Secondary suspensions play an essential role in the dynamic behaviour of rail vehicles. In particular, they are adopted to reduce the vibrations transmitted to the carbody, thus improving ride comfort. In this paper, an experimental characterization of the viscous damper and coil spring elements composing a vertical secondary suspension is presented. The elements are separately tested with the aim of analysing their dynamic behaviour. Then, modified prototypes are manufactured to reduce the transmitted force. The results of the experimental campaign are later adopted to tune the parameters of the mathematical model of the whole secondary suspension, including the dynamics of both the coil spring and the damper elements. This model allows discussing the effectiveness of the proposed modifications, proving the design of both the components to be fundamental for the improvement of ride comfort.","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":"2023-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82182668","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 : 2023-06-07DOI: 10.1177/09544097231174408
Hamed Petoft, A. Rahi, V. Fakhari
Hyperloop, a very high-speed transportation system including a pod transporting the passengers in a tube, forms the core debate in numerous recent investigations. The present paper, furthering the current advanced findings, proposes a novel hybrid levitation including Electro-Dynamic Suspension (EDS) and air cushions for the pod in the hyperloop system. It also presents a vibrational model for the hybrid levitation pod to predict the vibration behavior of the pod in accelerating and braking maneuvers. In this regard, an industrial pod is designed conceptually by performing preliminary calculations. Via CFD simulations in Ansys Fluent software, we hold forth a nonlinear dynamic model for the air cushions. Then, the paper analyzes a 3-DOF vibration model of the pod and verifies it by comparing the related results with obtained ones from the MSc ADAMS software. Afterward, the mentioned vibration model is developed into a 7-DOF model to predict the vibration behavior of the pod in accelerating and braking maneuvers. Also, the governing dynamic equations of the system are derived and numerically solved. Finally, the vibration behavior of the pod in different accelerating and braking conditions is investigated.
{"title":"Vibration analysis of a hyperloop pod with a novel hybrid levitation in accelerating and braking maneuvers","authors":"Hamed Petoft, A. Rahi, V. Fakhari","doi":"10.1177/09544097231174408","DOIUrl":"https://doi.org/10.1177/09544097231174408","url":null,"abstract":"Hyperloop, a very high-speed transportation system including a pod transporting the passengers in a tube, forms the core debate in numerous recent investigations. The present paper, furthering the current advanced findings, proposes a novel hybrid levitation including Electro-Dynamic Suspension (EDS) and air cushions for the pod in the hyperloop system. It also presents a vibrational model for the hybrid levitation pod to predict the vibration behavior of the pod in accelerating and braking maneuvers. In this regard, an industrial pod is designed conceptually by performing preliminary calculations. Via CFD simulations in Ansys Fluent software, we hold forth a nonlinear dynamic model for the air cushions. Then, the paper analyzes a 3-DOF vibration model of the pod and verifies it by comparing the related results with obtained ones from the MSc ADAMS software. Afterward, the mentioned vibration model is developed into a 7-DOF model to predict the vibration behavior of the pod in accelerating and braking maneuvers. Also, the governing dynamic equations of the system are derived and numerically solved. Finally, the vibration behavior of the pod in different accelerating and braking conditions is investigated.","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":"2023-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84429149","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 : 2023-06-06DOI: 10.1177/09544097231181450
I. Goryacheva, A. Meshcheryakova
This study presents the results of modelling the rolling contact of the elastic sphere and the elastic half-space in the presence of a thin intermediate viscoelastic layer which properties are described by an elastic nonlinear Winkler body in the normal direction and a viscoelastic Maxwell body in the tangential direction. The analytical–numerical approach for the estimation of contact fatigue damage, accumulated in the elastic half-space under rolling friction conditions, is developed. The proposed model can be used, in particular, to study the effect of mechanical properties of the friction modifiers (elastic moduli and relaxation times) and its thickness as well as the relative slippage on the formation of the surface and under surface contact fatigue cracks in rails. The results of the analysis can also be applied for the estimation of efficiency of solid lubricants in rolling contacts under given operating conditions.
{"title":"Modelling of rolling contact fatigue under various interface conditions","authors":"I. Goryacheva, A. Meshcheryakova","doi":"10.1177/09544097231181450","DOIUrl":"https://doi.org/10.1177/09544097231181450","url":null,"abstract":"This study presents the results of modelling the rolling contact of the elastic sphere and the elastic half-space in the presence of a thin intermediate viscoelastic layer which properties are described by an elastic nonlinear Winkler body in the normal direction and a viscoelastic Maxwell body in the tangential direction. The analytical–numerical approach for the estimation of contact fatigue damage, accumulated in the elastic half-space under rolling friction conditions, is developed. The proposed model can be used, in particular, to study the effect of mechanical properties of the friction modifiers (elastic moduli and relaxation times) and its thickness as well as the relative slippage on the formation of the surface and under surface contact fatigue cracks in rails. The results of the analysis can also be applied for the estimation of efficiency of solid lubricants in rolling contacts under given operating conditions.","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":"2023-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85977281","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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