Pub Date : 2023-07-29DOI: 10.1177/09544097231193186
M. Carboni, Marta Zamorano
Railway axles are safety-critical components of the rolling stock and the consequences of possible in-service failures can have dramatic effects. Although this element is traditionally designed against such failures, the initiation and propagation of service cracks are still occasionally observed, requiring an effective application of non-destructive testing and structural health monitoring approaches. This paper investigates the application of structural health monitoring by acoustic emission to the case of solid railway axles subject to fretting fatigue damage. A full-scale test was performed on a specimen in which artificial notches were suitably manufactured in order to cause the initiation and evolution of fretting fatigue damage up to the stage of relevant propagating fatigue cracks. During the test, both periodical phased array ultrasonic inspections and continuous acquisition of acoustic emission data have been carried out. Moreover, at the end of the test, the specimen was inspected, analyzed and evaluated by visual inspection and magnetic particles testing, while acoustic emission raw data were post-processed by a special unsupervised machine learning algorithm based on an Artificial Neural Network. It is demonstrated that the proposed methodology is very effective to detect the onset of crack initiation in a non-invasive and safe way.
{"title":"On monitoring fretting fatigue damage in solid railway axles by acoustic emission with unsupervised machine learning and comparison to non-destructive testing techniques","authors":"M. Carboni, Marta Zamorano","doi":"10.1177/09544097231193186","DOIUrl":"https://doi.org/10.1177/09544097231193186","url":null,"abstract":"Railway axles are safety-critical components of the rolling stock and the consequences of possible in-service failures can have dramatic effects. Although this element is traditionally designed against such failures, the initiation and propagation of service cracks are still occasionally observed, requiring an effective application of non-destructive testing and structural health monitoring approaches. This paper investigates the application of structural health monitoring by acoustic emission to the case of solid railway axles subject to fretting fatigue damage. A full-scale test was performed on a specimen in which artificial notches were suitably manufactured in order to cause the initiation and evolution of fretting fatigue damage up to the stage of relevant propagating fatigue cracks. During the test, both periodical phased array ultrasonic inspections and continuous acquisition of acoustic emission data have been carried out. Moreover, at the end of the test, the specimen was inspected, analyzed and evaluated by visual inspection and magnetic particles testing, while acoustic emission raw data were post-processed by a special unsupervised machine learning algorithm based on an Artificial Neural Network. It is demonstrated that the proposed methodology is very effective to detect the onset of crack initiation in a non-invasive and safe way.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":"37 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77778597","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 : 2023-07-25DOI: 10.1177/09544097231191550
M. Freisinger, A. Trausmuth, Rainer Hahn, E. Badisch
Severe mechanical and thermal loadings, as well as the corrosive environment change the near-surface microstructure of rail wheels during service. Resulting severely plastically deformed (SPD) and corrosion affected microstructures are prone to influence crack initiation along the wheel tread. To evaluate the crack initiation and fracture behaviour, the in-situ micro-bending method is first applied on rail wheel samples from field within this work. Results reveal detailed insights in material behaviour of SPD microstructures, where the conducted micro-bending investigations point out predominant plastic behaviour without cracks initiated at the artificial notch of the micro-cantilevers during bending. In contrast, micro-bending investigations in microstructural regions with increased oxygen and silicon composition show crack initiation, fracture, and low maximum stress levels (approximately one seventh of the SPD microstructure). The presented study underlines the increased risk of crack initiation in corrosion affected regions by a novel testing method in this field with high spatial resolution and acknowledge the importance of periodic reprofiling of the rail wheels in service.
{"title":"Influence of the evolution of near-surface rail wheel microstructure on crack initiation by micro-bending investigations","authors":"M. Freisinger, A. Trausmuth, Rainer Hahn, E. Badisch","doi":"10.1177/09544097231191550","DOIUrl":"https://doi.org/10.1177/09544097231191550","url":null,"abstract":"Severe mechanical and thermal loadings, as well as the corrosive environment change the near-surface microstructure of rail wheels during service. Resulting severely plastically deformed (SPD) and corrosion affected microstructures are prone to influence crack initiation along the wheel tread. To evaluate the crack initiation and fracture behaviour, the in-situ micro-bending method is first applied on rail wheel samples from field within this work. Results reveal detailed insights in material behaviour of SPD microstructures, where the conducted micro-bending investigations point out predominant plastic behaviour without cracks initiated at the artificial notch of the micro-cantilevers during bending. In contrast, micro-bending investigations in microstructural regions with increased oxygen and silicon composition show crack initiation, fracture, and low maximum stress levels (approximately one seventh of the SPD microstructure). The presented study underlines the increased risk of crack initiation in corrosion affected regions by a novel testing method in this field with high spatial resolution and acknowledge the importance of periodic reprofiling of the rail wheels in service.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":"44 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74844119","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 : 2023-07-25DOI: 10.1177/09544097231189535
P. Millan, J. Pagaimo, João Neves Costa, N. Maia, J. Ambrósio
The condition monitoring of the suspensions of railway vehicles is of utmost importance, allowing the reduction of the maintenance actions and the increase in the operational safety. However, the available methods often require a simplification of the vehicle through linearised models, a high number of sensors, or the use of complex algorithms that disregard the mechanical phenomena that explain the vehicle dynamics. This work suggests the Localized Transmissibility Damage Indicator (LTDI), based on the existing Transmissibility Damage Indicator (TDI), to detect damage in the springs of a locomotive, using pairs of sensors placed in the bogie frame and the axle boxes. For that purpose, multibody simulations are used to simulate the dynamic behaviour of the vehicle in tangent tracks under nominal and damaged conditions. The results from multibody simulations allow the calculation of the LTDI values for different levels of damage and various operation conditions, as well as the study of the effect of the variability inherent to the railway operation. The results show that the LTDI is significantly sensitive to damage. However, depending on the use of the lateral or vertical response, the LTDI is more suitable to detect the stiffness increase or decrease, or even to locate the damage. In conclusion, the LTDI is a promising method for the detection of damage on suspension elements of railway vehicles.
{"title":"On the use of transmissibility for the detection of damaged springs in the primary suspension of a locomotive","authors":"P. Millan, J. Pagaimo, João Neves Costa, N. Maia, J. Ambrósio","doi":"10.1177/09544097231189535","DOIUrl":"https://doi.org/10.1177/09544097231189535","url":null,"abstract":"The condition monitoring of the suspensions of railway vehicles is of utmost importance, allowing the reduction of the maintenance actions and the increase in the operational safety. However, the available methods often require a simplification of the vehicle through linearised models, a high number of sensors, or the use of complex algorithms that disregard the mechanical phenomena that explain the vehicle dynamics. This work suggests the Localized Transmissibility Damage Indicator (LTDI), based on the existing Transmissibility Damage Indicator (TDI), to detect damage in the springs of a locomotive, using pairs of sensors placed in the bogie frame and the axle boxes. For that purpose, multibody simulations are used to simulate the dynamic behaviour of the vehicle in tangent tracks under nominal and damaged conditions. The results from multibody simulations allow the calculation of the LTDI values for different levels of damage and various operation conditions, as well as the study of the effect of the variability inherent to the railway operation. The results show that the LTDI is significantly sensitive to damage. However, depending on the use of the lateral or vertical response, the LTDI is more suitable to detect the stiffness increase or decrease, or even to locate the damage. In conclusion, the LTDI is a promising method for the detection of damage on suspension elements of railway vehicles.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":"13 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87493000","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 : 2023-07-25DOI: 10.1177/09544097231190129
Chaotao Liu, Jia Zhang, Ye Song, Fansong Li, P. Wu
The dynamic performance of a high-speed train is heavily influenced by its centre of gravity and moment of inertia. Therefore, accurately measuring these parameters is crucial. This paper proposes an integrated test method for measuring the centre of gravity and moment of inertia based on the excitation method by analyzing the structural characteristics of the vibration test bench. The proposed method is efficient as it only requires installing the car body once, unlike the past method of combining excitation and suspension. This paper provides a comprehensive theoretical derivation of the method used to test the center of gravity and moment of inertia of a specific type of high-speed electrical motor units (EMU) car body. The results of the test were compared to the theoretical values, and the error was found to be minimal, meeting the necessary engineering application requirements.
{"title":"Research on measuring method of centre of gravity and moment of inertia for car body of high-speed EMUs","authors":"Chaotao Liu, Jia Zhang, Ye Song, Fansong Li, P. Wu","doi":"10.1177/09544097231190129","DOIUrl":"https://doi.org/10.1177/09544097231190129","url":null,"abstract":"The dynamic performance of a high-speed train is heavily influenced by its centre of gravity and moment of inertia. Therefore, accurately measuring these parameters is crucial. This paper proposes an integrated test method for measuring the centre of gravity and moment of inertia based on the excitation method by analyzing the structural characteristics of the vibration test bench. The proposed method is efficient as it only requires installing the car body once, unlike the past method of combining excitation and suspension. This paper provides a comprehensive theoretical derivation of the method used to test the center of gravity and moment of inertia of a specific type of high-speed electrical motor units (EMU) car body. The results of the test were compared to the theoretical values, and the error was found to be minimal, meeting the necessary engineering application requirements.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":"1 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90876360","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 : 2023-07-23DOI: 10.1177/09544097231189533
Baoan Zhang, Binbin Liu, E. Di Gialleonardo, Haitao Li, Jing Zheng, Yunqi Shi, S. Bruni
Past works have shown that the application of the non-Hertzian wheel/rail contact in the multibody system simulation may produce non-negligible differences in the results compared to the results obtained using the classical Hertzian approach. As a continuation of this research line, the running stability of a passenger rail vehicle running on tangent and curved tracks has been investigated considering the wheel/rail creep force being determined using Hertzian and non-Hertzian approaches, respectively. The results show that the creep force modelling has varied levels of influence on the estimation of the stability of a rail vehicle on both tangent and curved tracks depending on the non-ellipticity of the contact. The non-Hertzian model is recommended to be used for such kind of applications as the traditional Hertzian approach may misestimate the dynamics behaviour of the vehicle under certain circumstances.
{"title":"Influence of creep force modelling on the non-linear stability of a rail vehicle on tangent and curved tracks","authors":"Baoan Zhang, Binbin Liu, E. Di Gialleonardo, Haitao Li, Jing Zheng, Yunqi Shi, S. Bruni","doi":"10.1177/09544097231189533","DOIUrl":"https://doi.org/10.1177/09544097231189533","url":null,"abstract":"Past works have shown that the application of the non-Hertzian wheel/rail contact in the multibody system simulation may produce non-negligible differences in the results compared to the results obtained using the classical Hertzian approach. As a continuation of this research line, the running stability of a passenger rail vehicle running on tangent and curved tracks has been investigated considering the wheel/rail creep force being determined using Hertzian and non-Hertzian approaches, respectively. The results show that the creep force modelling has varied levels of influence on the estimation of the stability of a rail vehicle on both tangent and curved tracks depending on the non-ellipticity of the contact. The non-Hertzian model is recommended to be used for such kind of applications as the traditional Hertzian approach may misestimate the dynamics behaviour of the vehicle under certain circumstances.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":"106 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87974533","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 : 2023-07-18DOI: 10.1177/09544097231187679
Z. S. Lee, G. Trummer, M. Harmon, Ben White, K. Six, R. Lewis
The railway industry uses top-of-rail products to control and manage the friction in the wheel/rail interface to help ensure efficient train operations and reduce wheel and rail damage. A product is typically applied from a wayside applicator that pumps a puddle onto the rail head where a passing wheel will pick it up and then transfer it down the track. The aim of this study was to study the transfer mechanisms of water-based top-of-rail friction modifiers (TOR-FMs) and how they are linked to the friction conditions in the wheel/rail interface. The transfer mechanisms were split into three parts: pick-up, carry-on and consumption. Pick-up looks at how the product transfers from the puddle on the rail to a wheel tread, whereas the carry-on mechanism relates to the product transfer back to the wheel. Consumption focuses on the removal rate of the product layer from the wheel or rail. A full-scale rig and twin disc machine were chosen to perform the tests because each rig could give different insights into understanding the product transfer mechanisms. Two products were tested of similar formulation. Results show that there are differences in the transfer and friction between the two products despite them being relatively similar. The test methods developed can clearly resolve differences between varying product types, which could be useful for product development studies or approvals work. The outcomes could also be used to develop a model of transfer/consumption.
{"title":"Studying the transfer mechanisms of water based top-of-rail products in a wheel/rail interaction","authors":"Z. S. Lee, G. Trummer, M. Harmon, Ben White, K. Six, R. Lewis","doi":"10.1177/09544097231187679","DOIUrl":"https://doi.org/10.1177/09544097231187679","url":null,"abstract":"The railway industry uses top-of-rail products to control and manage the friction in the wheel/rail interface to help ensure efficient train operations and reduce wheel and rail damage. A product is typically applied from a wayside applicator that pumps a puddle onto the rail head where a passing wheel will pick it up and then transfer it down the track. The aim of this study was to study the transfer mechanisms of water-based top-of-rail friction modifiers (TOR-FMs) and how they are linked to the friction conditions in the wheel/rail interface. The transfer mechanisms were split into three parts: pick-up, carry-on and consumption. Pick-up looks at how the product transfers from the puddle on the rail to a wheel tread, whereas the carry-on mechanism relates to the product transfer back to the wheel. Consumption focuses on the removal rate of the product layer from the wheel or rail. A full-scale rig and twin disc machine were chosen to perform the tests because each rig could give different insights into understanding the product transfer mechanisms. Two products were tested of similar formulation. Results show that there are differences in the transfer and friction between the two products despite them being relatively similar. The test methods developed can clearly resolve differences between varying product types, which could be useful for product development studies or approvals work. The outcomes could also be used to develop a model of transfer/consumption.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":"5 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90633555","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 : 2023-07-17DOI: 10.1177/09544097231190242
F. Zhao, Dawei Chen, Jiali Liu, Weibin Wang, M. Vahdati
A simulation framework for three-dimensional particle trajectory tracking, snow accumulation and ice accretion modelling on solid bodies in high-speed air flow is presented. The framework, named HADICE, solves the aerodynamic flow field as Reynolds averaged Navier-Stokes (RANS), with optional hybrid RANS/LES capabilities for modelling complex turbulent flows. Particle trajectory tracking is performed in an Eulerian-Lagrangian approach and wall collision is modelled using a hard collision model with reflect condition and a momentum based trap condition. A novel accurate and robust iterative evaluation method for the local collection efficiency is proposed for arbitrary 3D geometry and flow. Ice accretion is modelled in a multi-step approach and iced geometry is updated through mesh deformation using a radial basis function (RBF) interpolation method. Snow accumulation and ice accretion predictions based on the framework are validated against climatic wind tunnel experimental measurements. A full 3D simulation is demonstrated for snow accumulation and ice accretion on a 1:8 scaled high-speed train model. Using the presented framework, snow accumulation and icing simulation for high-speed trains can be conducted in an accurate and efficient manner, which is of great importance for physical investigations and the design of anti-snow and ice protection systems.
{"title":"A framework for simulating snow accumulation and ice accretion on high-speed trains","authors":"F. Zhao, Dawei Chen, Jiali Liu, Weibin Wang, M. Vahdati","doi":"10.1177/09544097231190242","DOIUrl":"https://doi.org/10.1177/09544097231190242","url":null,"abstract":"A simulation framework for three-dimensional particle trajectory tracking, snow accumulation and ice accretion modelling on solid bodies in high-speed air flow is presented. The framework, named HADICE, solves the aerodynamic flow field as Reynolds averaged Navier-Stokes (RANS), with optional hybrid RANS/LES capabilities for modelling complex turbulent flows. Particle trajectory tracking is performed in an Eulerian-Lagrangian approach and wall collision is modelled using a hard collision model with reflect condition and a momentum based trap condition. A novel accurate and robust iterative evaluation method for the local collection efficiency is proposed for arbitrary 3D geometry and flow. Ice accretion is modelled in a multi-step approach and iced geometry is updated through mesh deformation using a radial basis function (RBF) interpolation method. Snow accumulation and ice accretion predictions based on the framework are validated against climatic wind tunnel experimental measurements. A full 3D simulation is demonstrated for snow accumulation and ice accretion on a 1:8 scaled high-speed train model. Using the presented framework, snow accumulation and icing simulation for high-speed trains can be conducted in an accurate and efficient manner, which is of great importance for physical investigations and the design of anti-snow and ice protection systems.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":"24 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73027545","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 : 2023-07-11DOI: 10.1177/09544097231187978
E. Steyn, B. Paulsson, A. Ekberg, E. Kabo
Current practices on rail machining show large variations in strategies and amount of grinding and milling. To identify reasons for this and suggest strategies to further optimise rail machining, objectives of machining are scrutinised and consequences of not fulfilling objectives are investigated. This leads to a discussion on potentially detrimental effects of rail machining and how to minimise these. With this background, general aspects of rail machining optimisation are discussed. The study shows several means to improve rail machining, but also how the potential is restricted by the current lack of knowledge and predictive models. This prevents quantifying benefits of innovative solutions, and complicates transfer of knowledge between different operational conditions and translations of (scaled and controlled) test results to (full-scale, uncontrolled) operational conditions.
{"title":"Rail machining – current practices and potential for optimisation","authors":"E. Steyn, B. Paulsson, A. Ekberg, E. Kabo","doi":"10.1177/09544097231187978","DOIUrl":"https://doi.org/10.1177/09544097231187978","url":null,"abstract":"Current practices on rail machining show large variations in strategies and amount of grinding and milling. To identify reasons for this and suggest strategies to further optimise rail machining, objectives of machining are scrutinised and consequences of not fulfilling objectives are investigated. This leads to a discussion on potentially detrimental effects of rail machining and how to minimise these. With this background, general aspects of rail machining optimisation are discussed. The study shows several means to improve rail machining, but also how the potential is restricted by the current lack of knowledge and predictive models. This prevents quantifying benefits of innovative solutions, and complicates transfer of knowledge between different operational conditions and translations of (scaled and controlled) test results to (full-scale, uncontrolled) operational conditions.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":"11 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88483136","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 : 2023-07-04DOI: 10.1177/09544097231186553
Ibon Erdozain, A. Alonso, J. Nieto, R. Lagos, E. Gómez
This work presents the main problems in the primary suspension of metro vehicles and a methodology to detect those using wayside systems. The primary suspension is usually based on rubber elements, which are space saving and have damping properties. However, rubber characteristics change with time, often in a different way in each element. Differences between elements can cause irregular transmission of loads to the wheels, and thus, a reduction or loss of guidance forces. The ageing of rubber can also lead to a general stiffening of the primary suspension, which increases the risk of derailment. This paper presents a wayside system that uses a few strain gauge bridges to detect those problems independently of the vehicle load and speed. Firstly, the system is developed by means of a multibody model. Secondly, a demonstrator is installed in an operating metro exploitation. Finally, the accuracy of the predictions is proven by testing some of the elements in the laboratory.
{"title":"A condition monitoring approach for the detection of defects in the primary suspension of railway vehicles","authors":"Ibon Erdozain, A. Alonso, J. Nieto, R. Lagos, E. Gómez","doi":"10.1177/09544097231186553","DOIUrl":"https://doi.org/10.1177/09544097231186553","url":null,"abstract":"This work presents the main problems in the primary suspension of metro vehicles and a methodology to detect those using wayside systems. The primary suspension is usually based on rubber elements, which are space saving and have damping properties. However, rubber characteristics change with time, often in a different way in each element. Differences between elements can cause irregular transmission of loads to the wheels, and thus, a reduction or loss of guidance forces. The ageing of rubber can also lead to a general stiffening of the primary suspension, which increases the risk of derailment. This paper presents a wayside system that uses a few strain gauge bridges to detect those problems independently of the vehicle load and speed. Firstly, the system is developed by means of a multibody model. Secondly, a demonstrator is installed in an operating metro exploitation. Finally, the accuracy of the predictions is proven by testing some of the elements in the laboratory.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":"20 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87315700","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 : 2023-07-03DOI: 10.1177/09544097231175531
Pu Wang, Zhenhua Zhao, Junqi Ma, Shuguo Wang
In this paper, to address the shortcomings of the crossing structure design based on the elastic bending center method and the lack of related research, an optimization method for high-speed turnout crossing structures was proposed based on the actual elastic deformations of point and splice rails. Based on the finite element theory, the actual loading characteristics and spatial variable section characteristics of point and splice rails were fully considered, and a refined simulation analysis model of the switching system of point and splice rails in crossing areas was established. Moreover, the elastic deformation lines of point and splice rails in the nonworking state were obtained for the first time, which were consistent with actual situations. On this basis, system optimization was performed for the connecting parts of the crossing with a movable point in a high-speed turnout. In the crossing structure simulation model, the length adjustment values of the first–sixth spacer blocks between the branch line–wing and point rails and between the mail line–wing splice rails were ≤1 mm. Moreover, the lengths of the seventh–ninth spacer blocks decreased by gradually increasing amounts, and the length of the ninth spacer block decreased the most (∼6 mm). The length of the second spacer block between the point and splice rails slightly increased, but the length of the third spacer block significantly decreased by 6 mm. The length adjustment value of the distance block between the point and splice rails was smallest (0.7 mm). The calculated optimal lengths of the connecting parts of the crossing were found to be close to the empirical values used in actual manufacturing processes, and the dimension optimization patterns were completely consistent with actual situation, which validates the proposed optimization method. Thus, the proposed method can effectively improve the coordination between rails and connecting parts in crossing areas, substantially reduce internal stresses in crossing systems, and improve their assembly performance and service life. Moreover, the proposed optimization parameters can provide valuable references for the research on next-generation high-speed turnouts (400 km/h) and for improving the designs of existing high-speed turnouts.
{"title":"Study on the optimization of high-speed turnout crossing structures based on actual elastic deformation of point and splice rails","authors":"Pu Wang, Zhenhua Zhao, Junqi Ma, Shuguo Wang","doi":"10.1177/09544097231175531","DOIUrl":"https://doi.org/10.1177/09544097231175531","url":null,"abstract":"In this paper, to address the shortcomings of the crossing structure design based on the elastic bending center method and the lack of related research, an optimization method for high-speed turnout crossing structures was proposed based on the actual elastic deformations of point and splice rails. Based on the finite element theory, the actual loading characteristics and spatial variable section characteristics of point and splice rails were fully considered, and a refined simulation analysis model of the switching system of point and splice rails in crossing areas was established. Moreover, the elastic deformation lines of point and splice rails in the nonworking state were obtained for the first time, which were consistent with actual situations. On this basis, system optimization was performed for the connecting parts of the crossing with a movable point in a high-speed turnout. In the crossing structure simulation model, the length adjustment values of the first–sixth spacer blocks between the branch line–wing and point rails and between the mail line–wing splice rails were ≤1 mm. Moreover, the lengths of the seventh–ninth spacer blocks decreased by gradually increasing amounts, and the length of the ninth spacer block decreased the most (∼6 mm). The length of the second spacer block between the point and splice rails slightly increased, but the length of the third spacer block significantly decreased by 6 mm. The length adjustment value of the distance block between the point and splice rails was smallest (0.7 mm). The calculated optimal lengths of the connecting parts of the crossing were found to be close to the empirical values used in actual manufacturing processes, and the dimension optimization patterns were completely consistent with actual situation, which validates the proposed optimization method. Thus, the proposed method can effectively improve the coordination between rails and connecting parts in crossing areas, substantially reduce internal stresses in crossing systems, and improve their assembly performance and service life. Moreover, the proposed optimization parameters can provide valuable references for the research on next-generation high-speed turnouts (400 km/h) and for improving the designs of existing high-speed turnouts.","PeriodicalId":54567,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part F-Journal of Rail and Rapid Transit","volume":"9 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79292274","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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