Pub Date : 2024-07-01DOI: 10.1177/09544097231219827
Pedro Rodrigues, Paulo F. Teixeira
The geometric recovery achieved with tamping is affected by several factors, including maintenance history, ballast condition, type of tamping, age and configuration of track components, operational speeds, and human factors. In this paper, data from 2,819 defects of longitudinal levelling are analysed considering 66,892 km of inspections carried out on 19 lines of the Portuguese railway network over 10 years. The influence of infrastructure clusters, defect level, ballast age, degradation rate before tamping, and the still little-studied shape of defects on geometry recovery is firstly investigated by analysing relationships between the raw data (scatterplots). A multiple linear regression model is then developed to predict the defect level after tamping, taking into account both the defect level before tamping and its shape, which is modelled through a proxy parameter. It is concluded that track sections where there are singularities (underpasses, culverts, level crossings, bridges, tunnels and viaducts) usually have much shorter maintenance cycles (median values up to 60% lower). Ballast age and degradation rate before tamping did not prove to have a marked influence on geometry recovery. Although the defect level before tamping is found to be the factor that most conditions geometry recovery, thus corroborating the critical importance of timely intervention, its shape also proves to have a significant influence, giving rise to differences in geometry recovery of up to 20% of the defect level before tamping.
{"title":"Modelling tamping effectiveness for track geometry longitudinal levelling defects","authors":"Pedro Rodrigues, Paulo F. Teixeira","doi":"10.1177/09544097231219827","DOIUrl":"https://doi.org/10.1177/09544097231219827","url":null,"abstract":"The geometric recovery achieved with tamping is affected by several factors, including maintenance history, ballast condition, type of tamping, age and configuration of track components, operational speeds, and human factors. In this paper, data from 2,819 defects of longitudinal levelling are analysed considering 66,892 km of inspections carried out on 19 lines of the Portuguese railway network over 10 years. The influence of infrastructure clusters, defect level, ballast age, degradation rate before tamping, and the still little-studied shape of defects on geometry recovery is firstly investigated by analysing relationships between the raw data (scatterplots). A multiple linear regression model is then developed to predict the defect level after tamping, taking into account both the defect level before tamping and its shape, which is modelled through a proxy parameter. It is concluded that track sections where there are singularities (underpasses, culverts, level crossings, bridges, tunnels and viaducts) usually have much shorter maintenance cycles (median values up to 60% lower). Ballast age and degradation rate before tamping did not prove to have a marked influence on geometry recovery. Although the defect level before tamping is found to be the factor that most conditions geometry recovery, thus corroborating the critical importance of timely intervention, its shape also proves to have a significant influence, giving rise to differences in geometry recovery of up to 20% of the defect level before tamping.","PeriodicalId":515695,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit","volume":"7 1","pages":"662 - 674"},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141705557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-14DOI: 10.1177/09544097241262395
Biao Zheng, Lai Wei, Jing Zeng, Caihong Huang
In the past, bogie hunting instability garnered more attention due to its potential for causing serious safety issues. However, with the rise in high-speed vehicle speeds and operational mileage, the concerns arising from carbody hunting can no longer be overlooked. This article investigates the causes and solutions for low-frequency carbody swaying under low effective conicity in wheel-rail contact, employing a combination of experimental and numerical techniques. Initially, the study involves an in-depth analysis of time-domain signals from lateral and vertical accelerations of the carbody and bogie frame during a high-speed train field-test. The carbody vibration mode resulting from carbody hunting displays a swaying motion at a frequency of 1.5 Hz. Subsequently, a dynamic system model of the high-speed vehicle was established and the suspension mode of the model were verified. The frequency of the carbody upper sway motion is determined to be 1.39 Hz. Low effective conicity is induced when grinding wheel match with new rail or new wheel match with grinding rail. Under this low effective conicity, the hunting frequency of the vehicle is around 1.5 Hz, close to the frequency of the carbody upper sway motion. The coincidence of the hunting frequency and the upper sway motion frequency leads to the low-frequency swaying of the carbody. At last, the effects of wheel profiles, rail profiles and suspension parameters on the carbody hunting have been studied. The study demonstrates that addressing low-frequency carbody swaying can be achieved through targeted rail grinding. This process involves modifying the rail profile while ensuring careful grinding of the rail inner corner. Furthermore, it has been confirmed in the article that replacing suitable yaw dampers is also effective.
{"title":"Carbody hunting behaviour of high speed vehicles in low effective conicity of wheel-rail contact","authors":"Biao Zheng, Lai Wei, Jing Zeng, Caihong Huang","doi":"10.1177/09544097241262395","DOIUrl":"https://doi.org/10.1177/09544097241262395","url":null,"abstract":"In the past, bogie hunting instability garnered more attention due to its potential for causing serious safety issues. However, with the rise in high-speed vehicle speeds and operational mileage, the concerns arising from carbody hunting can no longer be overlooked. This article investigates the causes and solutions for low-frequency carbody swaying under low effective conicity in wheel-rail contact, employing a combination of experimental and numerical techniques. Initially, the study involves an in-depth analysis of time-domain signals from lateral and vertical accelerations of the carbody and bogie frame during a high-speed train field-test. The carbody vibration mode resulting from carbody hunting displays a swaying motion at a frequency of 1.5 Hz. Subsequently, a dynamic system model of the high-speed vehicle was established and the suspension mode of the model were verified. The frequency of the carbody upper sway motion is determined to be 1.39 Hz. Low effective conicity is induced when grinding wheel match with new rail or new wheel match with grinding rail. Under this low effective conicity, the hunting frequency of the vehicle is around 1.5 Hz, close to the frequency of the carbody upper sway motion. The coincidence of the hunting frequency and the upper sway motion frequency leads to the low-frequency swaying of the carbody. At last, the effects of wheel profiles, rail profiles and suspension parameters on the carbody hunting have been studied. The study demonstrates that addressing low-frequency carbody swaying can be achieved through targeted rail grinding. This process involves modifying the rail profile while ensuring careful grinding of the rail inner corner. Furthermore, it has been confirmed in the article that replacing suitable yaw dampers is also effective.","PeriodicalId":515695,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit","volume":"76 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141342551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-22DOI: 10.1177/09544097241255718
Aliakbar Abbasi, J. Zakeri, Ehsan Norouzi, S. Mosayebi
Due to increasing train speed and passage tonnage, the repair and maintenance of ballasted railway tracks is essential. As a result of cyclic train loads on ballasted tracks, the ballast layer can deteriorate. When the ballast bed deteriorates, it can change the track geometry, which leads to uncomfortable ride and an increase in wheel-rail interaction. Tamping is one of the most widely used methods for filling the ballast layer gaps around sleepers and homogenizing ballast beds in order to align the track geometry. After passing the tamping machine, the dynamic stabilizing machine is utilized to improve the quality of the ballast bed. The rail support modulus is an essential parameter for analyzing ballasted railway tracks, and it can change after maintenance operations. This paper extensively discusses the effects of maintenance operations on rail support modulus as an essential safety factor in ballasted tracks. In this study, a series of field tests are planned and conducted at Karaj station in Iran to investigate the effects of passing tamping and stabilizing machines on the rail support modulus in ballasted tracks. In this regard, the rail support modulus of the ballasted track according to deflection basins was measured in three stages (before tamping, after tamping, and after stabilizing), and the results were analyzed to determine the effects of passing maintenance machines on ballast beds. Based on the results, the tamping operation results in a 75.5% reduction in the rail support modulus, and after stabilizing the railway track, the rail support modulus is increased by 35.8%.
{"title":"Field investigation on the effect of the tamping machine and dynamic track stabilizer on changing the rail support modulus","authors":"Aliakbar Abbasi, J. Zakeri, Ehsan Norouzi, S. Mosayebi","doi":"10.1177/09544097241255718","DOIUrl":"https://doi.org/10.1177/09544097241255718","url":null,"abstract":"Due to increasing train speed and passage tonnage, the repair and maintenance of ballasted railway tracks is essential. As a result of cyclic train loads on ballasted tracks, the ballast layer can deteriorate. When the ballast bed deteriorates, it can change the track geometry, which leads to uncomfortable ride and an increase in wheel-rail interaction. Tamping is one of the most widely used methods for filling the ballast layer gaps around sleepers and homogenizing ballast beds in order to align the track geometry. After passing the tamping machine, the dynamic stabilizing machine is utilized to improve the quality of the ballast bed. The rail support modulus is an essential parameter for analyzing ballasted railway tracks, and it can change after maintenance operations. This paper extensively discusses the effects of maintenance operations on rail support modulus as an essential safety factor in ballasted tracks. In this study, a series of field tests are planned and conducted at Karaj station in Iran to investigate the effects of passing tamping and stabilizing machines on the rail support modulus in ballasted tracks. In this regard, the rail support modulus of the ballasted track according to deflection basins was measured in three stages (before tamping, after tamping, and after stabilizing), and the results were analyzed to determine the effects of passing maintenance machines on ballast beds. Based on the results, the tamping operation results in a 75.5% reduction in the rail support modulus, and after stabilizing the railway track, the rail support modulus is increased by 35.8%.","PeriodicalId":515695,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit","volume":"96 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141111592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-14DOI: 10.1177/09544097241254146
Yong Peng, Zhengsheng Hu, Min Deng, Kui Wang, Yangyang Yu, Quanwei Che, Gong Deng
The increasing number of train–moose collision accidents threatens train running safety. This study investigated the bullet train–moose collision process and explored the effect of parameters on the dynamic responses. The multibody (MB) model was developed and validated against real–world collisions and the validated finite element model. A parametric study including the moose size, train speed, moose velocity, moose offset, and impact angle was conducted using MADYMO software. The lateral and longitudinal displacements of the moose’s center of gravity (CG) were used to evaluate the crash safety. The results showed that the moose size significantly affects moose impact dynamics and kinematics. The velocity and the offset of the moose were positively correlated with the lateral displacement. However, there was an obvious nonlinear relationship between the train speed and the lateral displacement. With the increase in the collision speed, the front–end deformation weakens the obstacle removal effect of the front hatch. The landing spots of the small–sized moose were the most concentrated, which means greater risk of secondary collisions. This study provides practical help for improving the running safety of high–speed trains and protecting wild animals along railways.
{"title":"High–speed train crash safety assessment for Train–moose collisions","authors":"Yong Peng, Zhengsheng Hu, Min Deng, Kui Wang, Yangyang Yu, Quanwei Che, Gong Deng","doi":"10.1177/09544097241254146","DOIUrl":"https://doi.org/10.1177/09544097241254146","url":null,"abstract":"The increasing number of train–moose collision accidents threatens train running safety. This study investigated the bullet train–moose collision process and explored the effect of parameters on the dynamic responses. The multibody (MB) model was developed and validated against real–world collisions and the validated finite element model. A parametric study including the moose size, train speed, moose velocity, moose offset, and impact angle was conducted using MADYMO software. The lateral and longitudinal displacements of the moose’s center of gravity (CG) were used to evaluate the crash safety. The results showed that the moose size significantly affects moose impact dynamics and kinematics. The velocity and the offset of the moose were positively correlated with the lateral displacement. However, there was an obvious nonlinear relationship between the train speed and the lateral displacement. With the increase in the collision speed, the front–end deformation weakens the obstacle removal effect of the front hatch. The landing spots of the small–sized moose were the most concentrated, which means greater risk of secondary collisions. This study provides practical help for improving the running safety of high–speed trains and protecting wild animals along railways.","PeriodicalId":515695,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit","volume":"29 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140981294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-25DOI: 10.1177/09544097241245598
Shuai Chen, Guotang Zhao, Jian Han, Ping Wang, Hengyu Wang
To establish the constitutive relation of corrugated rail material, rail corrugation was reproduced. The material mechanical properties of corrugation peaks and troughs were obtained by experiment. A set of dimensionless functions was proposed for the elastic modulus, hardness and yield stress at arbitrary depth of corrugation peaks and troughs. By combining the finite element model and dimensional functions, the constitutive relations were obtained at different vertical and lateral positions of corrugation. The closer the material is to the rail surface, the larger the mechanical property values. The elastic modulus and hardness of corrugated rail material at the trough surface are higher than those at the peak, while the yield stress at the peak surface is higher than the trough.
{"title":"An investigation into the constitutive relation of corrugated metro rail material based on nano-indentation experiment and inverse analysis","authors":"Shuai Chen, Guotang Zhao, Jian Han, Ping Wang, Hengyu Wang","doi":"10.1177/09544097241245598","DOIUrl":"https://doi.org/10.1177/09544097241245598","url":null,"abstract":"To establish the constitutive relation of corrugated rail material, rail corrugation was reproduced. The material mechanical properties of corrugation peaks and troughs were obtained by experiment. A set of dimensionless functions was proposed for the elastic modulus, hardness and yield stress at arbitrary depth of corrugation peaks and troughs. By combining the finite element model and dimensional functions, the constitutive relations were obtained at different vertical and lateral positions of corrugation. The closer the material is to the rail surface, the larger the mechanical property values. The elastic modulus and hardness of corrugated rail material at the trough surface are higher than those at the peak, while the yield stress at the peak surface is higher than the trough.","PeriodicalId":515695,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit","volume":"73 20","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140655355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-09DOI: 10.1177/09544097241233039
Linping Sun, Zhongliang Yang, Weihua Ma, S. Luo, Bo Wang
In order to explain the wheel-rail stick-slip vibration phenomenon of alocomotive in a curve, a co-simulation dynamic model taking into account adhesion control was established to reproduce the locomotive wheel-rail curve stick-slip vibration behavior, and the effect of parameters such as creep threshold, descent slope, rail surface condition and track curve radius on the stick-slip vibration behavior was measured by the traction force and the overall dispersion of adhesion coefficient. The results illustrate that the wheel-rail curve stick-slip vibration is caused by the dynamic traction force fluctuation under the adhesion control, and the increase of creep threshold will lead to the decrease of tractive force fluctuation amplitude and the decrease of stick-slip vibration intensity, which will increase the adhesion utilization rate, However, the increase of descent slope, the decrease of track curve radius and wheel-rail friction coefficient have the opposite effect on stick-slip vibration behavior. This phenomenon can be eliminated by improving the rail surface condition, expanding the track curve radius and lowering the locomotive traction force.
{"title":"Investigating the stick-slip vibration behavior of a locomotive with adhesion control in a curve","authors":"Linping Sun, Zhongliang Yang, Weihua Ma, S. Luo, Bo Wang","doi":"10.1177/09544097241233039","DOIUrl":"https://doi.org/10.1177/09544097241233039","url":null,"abstract":"In order to explain the wheel-rail stick-slip vibration phenomenon of alocomotive in a curve, a co-simulation dynamic model taking into account adhesion control was established to reproduce the locomotive wheel-rail curve stick-slip vibration behavior, and the effect of parameters such as creep threshold, descent slope, rail surface condition and track curve radius on the stick-slip vibration behavior was measured by the traction force and the overall dispersion of adhesion coefficient. The results illustrate that the wheel-rail curve stick-slip vibration is caused by the dynamic traction force fluctuation under the adhesion control, and the increase of creep threshold will lead to the decrease of tractive force fluctuation amplitude and the decrease of stick-slip vibration intensity, which will increase the adhesion utilization rate, However, the increase of descent slope, the decrease of track curve radius and wheel-rail friction coefficient have the opposite effect on stick-slip vibration behavior. This phenomenon can be eliminated by improving the rail surface condition, expanding the track curve radius and lowering the locomotive traction force.","PeriodicalId":515695,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit","volume":"79 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139848565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-09DOI: 10.1177/09544097241233039
Linping Sun, Zhongliang Yang, Weihua Ma, S. Luo, Bo Wang
In order to explain the wheel-rail stick-slip vibration phenomenon of alocomotive in a curve, a co-simulation dynamic model taking into account adhesion control was established to reproduce the locomotive wheel-rail curve stick-slip vibration behavior, and the effect of parameters such as creep threshold, descent slope, rail surface condition and track curve radius on the stick-slip vibration behavior was measured by the traction force and the overall dispersion of adhesion coefficient. The results illustrate that the wheel-rail curve stick-slip vibration is caused by the dynamic traction force fluctuation under the adhesion control, and the increase of creep threshold will lead to the decrease of tractive force fluctuation amplitude and the decrease of stick-slip vibration intensity, which will increase the adhesion utilization rate, However, the increase of descent slope, the decrease of track curve radius and wheel-rail friction coefficient have the opposite effect on stick-slip vibration behavior. This phenomenon can be eliminated by improving the rail surface condition, expanding the track curve radius and lowering the locomotive traction force.
{"title":"Investigating the stick-slip vibration behavior of a locomotive with adhesion control in a curve","authors":"Linping Sun, Zhongliang Yang, Weihua Ma, S. Luo, Bo Wang","doi":"10.1177/09544097241233039","DOIUrl":"https://doi.org/10.1177/09544097241233039","url":null,"abstract":"In order to explain the wheel-rail stick-slip vibration phenomenon of alocomotive in a curve, a co-simulation dynamic model taking into account adhesion control was established to reproduce the locomotive wheel-rail curve stick-slip vibration behavior, and the effect of parameters such as creep threshold, descent slope, rail surface condition and track curve radius on the stick-slip vibration behavior was measured by the traction force and the overall dispersion of adhesion coefficient. The results illustrate that the wheel-rail curve stick-slip vibration is caused by the dynamic traction force fluctuation under the adhesion control, and the increase of creep threshold will lead to the decrease of tractive force fluctuation amplitude and the decrease of stick-slip vibration intensity, which will increase the adhesion utilization rate, However, the increase of descent slope, the decrease of track curve radius and wheel-rail friction coefficient have the opposite effect on stick-slip vibration behavior. This phenomenon can be eliminated by improving the rail surface condition, expanding the track curve radius and lowering the locomotive traction force.","PeriodicalId":515695,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit","volume":" 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139788760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-08DOI: 10.1177/09544097241232553
Pedro Rodrigues, Paulo F Teixeira
The degradation of track geometry is a very complex phenomenon that has typically been analysed considering global quality indicators. In this paper, the influence of ballast and track substructure on its geometric degradation is analysed by modelling the degradation rates of more than 17,400 local defects of longitudinal levelling, alignment, and twist from 66,892 km of track inspection measurements carried out during the period 2001-2012 on 19 conventional lines of the Portuguese railway network. It is corroborated that singularities markedly contribute to greater density and faster degradation of defects, especially culverts and level crossings. Ballast type and age significantly affect the probability of emergence and degradation rates of defects. In a significant number of situations, defects are found to degrade much faster than the standard deviation indicators, highlighting the importance of monitoring and modelling their evolution to prevent the need for carrying out corrective interventions as much as possible.
{"title":"Influence of ballast and railway substructure on the degradation of local geometry defects","authors":"Pedro Rodrigues, Paulo F Teixeira","doi":"10.1177/09544097241232553","DOIUrl":"https://doi.org/10.1177/09544097241232553","url":null,"abstract":"The degradation of track geometry is a very complex phenomenon that has typically been analysed considering global quality indicators. In this paper, the influence of ballast and track substructure on its geometric degradation is analysed by modelling the degradation rates of more than 17,400 local defects of longitudinal levelling, alignment, and twist from 66,892 km of track inspection measurements carried out during the period 2001-2012 on 19 conventional lines of the Portuguese railway network. It is corroborated that singularities markedly contribute to greater density and faster degradation of defects, especially culverts and level crossings. Ballast type and age significantly affect the probability of emergence and degradation rates of defects. In a significant number of situations, defects are found to degrade much faster than the standard deviation indicators, highlighting the importance of monitoring and modelling their evolution to prevent the need for carrying out corrective interventions as much as possible.","PeriodicalId":515695,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit","volume":"78 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139852876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-08DOI: 10.1177/09544097241232553
Pedro Rodrigues, Paulo F Teixeira
The degradation of track geometry is a very complex phenomenon that has typically been analysed considering global quality indicators. In this paper, the influence of ballast and track substructure on its geometric degradation is analysed by modelling the degradation rates of more than 17,400 local defects of longitudinal levelling, alignment, and twist from 66,892 km of track inspection measurements carried out during the period 2001-2012 on 19 conventional lines of the Portuguese railway network. It is corroborated that singularities markedly contribute to greater density and faster degradation of defects, especially culverts and level crossings. Ballast type and age significantly affect the probability of emergence and degradation rates of defects. In a significant number of situations, defects are found to degrade much faster than the standard deviation indicators, highlighting the importance of monitoring and modelling their evolution to prevent the need for carrying out corrective interventions as much as possible.
{"title":"Influence of ballast and railway substructure on the degradation of local geometry defects","authors":"Pedro Rodrigues, Paulo F Teixeira","doi":"10.1177/09544097241232553","DOIUrl":"https://doi.org/10.1177/09544097241232553","url":null,"abstract":"The degradation of track geometry is a very complex phenomenon that has typically been analysed considering global quality indicators. In this paper, the influence of ballast and track substructure on its geometric degradation is analysed by modelling the degradation rates of more than 17,400 local defects of longitudinal levelling, alignment, and twist from 66,892 km of track inspection measurements carried out during the period 2001-2012 on 19 conventional lines of the Portuguese railway network. It is corroborated that singularities markedly contribute to greater density and faster degradation of defects, especially culverts and level crossings. Ballast type and age significantly affect the probability of emergence and degradation rates of defects. In a significant number of situations, defects are found to degrade much faster than the standard deviation indicators, highlighting the importance of monitoring and modelling their evolution to prevent the need for carrying out corrective interventions as much as possible.","PeriodicalId":515695,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit","volume":" 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139793083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper introduces a non-contact method for detecting contact force between pantograph and catenary (PAC), based on image processing and Kalman filter. A non-contact method for detecting contact force of PAC, which only utilizes the vertical displacement of the collector head, is proposed. First, the images of the collector head area are collected by adding an image acquisition system on the roof of the vehicle. Second, combined with target tracking and template matching, the vertical displacement of the pantograph’s collector head is identified. Finally, based on the Kalman filter considering least squares method and the PAC dynamics model, a method for detecting contact force is constructed. The estimation of the PAC’s dynamic contact force is realized only by using the vertical displacement of the collector head obtained from the image identification. The results of simulation and test-bed results show that the Kalman filter considering least squares significantly has higher accuracy and better robustness compared with the traditional Kalman filter.
{"title":"Non-contact detection method for pantograph-catenary contact force based on image processing","authors":"Hong-ming Chen, Zhou Ning, Cheng Yao, Wei-hua Zhang","doi":"10.1177/09544097241230358","DOIUrl":"https://doi.org/10.1177/09544097241230358","url":null,"abstract":"This paper introduces a non-contact method for detecting contact force between pantograph and catenary (PAC), based on image processing and Kalman filter. A non-contact method for detecting contact force of PAC, which only utilizes the vertical displacement of the collector head, is proposed. First, the images of the collector head area are collected by adding an image acquisition system on the roof of the vehicle. Second, combined with target tracking and template matching, the vertical displacement of the pantograph’s collector head is identified. Finally, based on the Kalman filter considering least squares method and the PAC dynamics model, a method for detecting contact force is constructed. The estimation of the PAC’s dynamic contact force is realized only by using the vertical displacement of the collector head obtained from the image identification. The results of simulation and test-bed results show that the Kalman filter considering least squares significantly has higher accuracy and better robustness compared with the traditional Kalman filter.","PeriodicalId":515695,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit","volume":"14 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139855119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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