Academic literature on the topic 'Rail track defects'
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Journal articles on the topic "Rail track defects"
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Zheng, Danyang, Liming Li, Shubin Zheng, Xiaodong Chai, Shuguang Zhao, Qianqian Tong, Ji Wang, and Lizheng Guo. "A Defect Detection Method for Rail Surface and Fasteners Based on Deep Convolutional Neural Network." Computational Intelligence and Neuroscience 2021 (July 29, 2021): 1–15. http://dx.doi.org/10.1155/2021/2565500.
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As a result of long-term pressure from train operations and direct exposure to the natural environment, rails, fasteners, and other components of railway track lines inevitably produce defects, which have a direct impact on the safety of train operations. In this study, a multiobject detection method based on deep convolutional neural network that can achieve nondestructive detection of rail surface and fastener defects is proposed. First, rails and fasteners on the railway track image are localized by the improved YOLOv5 framework. Then, the defect detection model based on Mask R-CNN is utilized to detect the surface defects of the rail and segment the defect area. Finally, the model based on ResNet framework is used to classify the state of the fasteners. To verify the robustness and effectiveness of our proposed method, we conduct experimental tests using the ballast and ballastless railway track images collected from Shijiazhuang-Taiyuan high-speed railway line. Through a variety of evaluation indexes to compare with other methods using deep learning algorithms, experimental results show that our method outperforms others in all stages and enables effective detection of rail surface and fasteners.
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Zakeri, Jabbar-Ali, and Roshan Talebi. "Experimental investigation into the effect of steel sleeper vertical stiffeners on railway track lateral resistance." Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 231, no. 1 (August 4, 2016): 104–10. http://dx.doi.org/10.1177/0954409715622500.
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Continuously welded rails are a common remedy to prevent rail defects, including railhead batter, rail cracking or breakage, and lateral displacement of track, among others. However, at curves with a radius of less than 400 m, rail welding is practically impossible due to the lack of track lateral resistance. Therefore, finding a new method to increase the track lateral resistance is necessary to facilitate rail welding, especially on tracks with steel sleepers. This study proposes a new method of increasing the lateral resistance of a ballasted track with steel sleepers by using web stiffeners. The effect of such stiffeners is investigated through a comparison with tracks having regular steel sleepers. The single tie (sleeper) push test is used in this research. The results of the experimental investigations show that the lateral resistance increases by 24, 140, and 203 percent, respectively, with the use of one, two, and three web stiffeners under the steel sleeper compared with a steel sleeper without stiffeners. Thus, the use of two stiffeners is concluded to provide enough lateral resistance in the case of older tracks. Therefore, the welding of rails at tight curves becomes conceivable.
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Guo, Long, Jun Zhang, Zhe Chen, Liang Sun, Jia Ge, Kun Lin Lü, and Guang Yu Dai. "Automatic Detection for Defects of Railroad Track Surface." Applied Mechanics and Materials 278-280 (January 2013): 856–60. http://dx.doi.org/10.4028/www.scientific.net/amm.278-280.856.
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Rail track surface defects detection is an important part of the monitoring of railroad safety. In this paper, rail track images obtained by detection system of rail track surface image are processed. Firstly, the Hough transform is applied to process the images of the track surface to locate and extract the image of the track surface, which overcomes the influence of incline and unfixed width of track surface images caused by vehicle vibration. Secondly, improved Sobel operator and area filter are used together to extract track surface defects from the original images. Finally, the defects images are classified based on circularity and length-width ratio of minimum enclosing rectangular of defects images.Results of experiments show that the algorithm can identify and classify the defects images of track surface. The minimum detection region in rail track surface is 0.0068 cm2.
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Fesharaki, Mohammad, and Ton-Lo Wang. "The Effect of Rail Defects on Track Impact Factors." Civil Engineering Journal 2, no. 9 (October 2, 2016): 458–73. http://dx.doi.org/10.28991/cej-2016-00000049.
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This paper investigates the effect of rail surface flaws on track impact factors for different track and vehicle conditions. For this purpose, a three dimensional vehicle and track as an integrated system modelled. The vehicle, consists car body, bogie frames and wheelsets, is able to model displacements in vertical and lateral directions. Hertz nonlinear springs utilized to connect vehicle to track structure and simulate the interaction between vehicle and track subsystems. Track comprises rail, rail pads, sleepers and ballast materials. For each subsystem, matrices of mass, stiffness and damping were formed and then matrices of total vehicle-track system considering their interaction were solved. Using FRA spectral density functions for rail irregularities, response of track with different qualities to train dynamic forces obtained. Rail random irregularities, rail corrugation and rail joint defects as three common rail defects have been considered in this paper. For each defects the influence of different track and train parameters on impact factor has been studied. The results of study indicate substantial effect of the depth and frequency of the rail flaws on impact factors. This paper has also considered the impact of vehicle speed on dynamic forces and found the critical speed for each case.
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Ling, Liang, Jian Han, Xinbiao Xiao, and Xuesong Jin. "Dynamic behavior of an embedded rail track coupled with a tram vehicle." Journal of Vibration and Control 23, no. 14 (November 15, 2015): 2355–72. http://dx.doi.org/10.1177/1077546315616521.
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This paper presents an investigation into the dynamic behavior of an embedded rail track coupled with a tram vehicle in time domain. A new designed embedded rail track structure firstly introduced into the Chinese tramways is described and the results of vibration tests of the embedded rail track (ERT) and another fastened slab track (FST) are discussed. A three-dimensional (3D) dynamic model of a tram vehicle coupled with an embedded rail track was developed on the basis of the multi-body dynamics approach and the finite element method. In the model, the tram vehicle was modeled as a multi-body system. The embedded rail track was modeled as a two layer system consisting of two rails, filling material, slabs, and adjustment layer beneath slabs. The rails were treated as Timoshenko beams with continuous elastic supports, in which the modal superposition method was used to reduce the order of the partial differential equations of beams. Continuous viscoelastic elements were used to represent the filling material and rail pad that connecting the rails and the slabs. The concrete slabs were modelled using the 3D finite element method, while the modal superposition method was adopted to improve the computational efficiency. Uniformly viscoelastic elements were introduced to model the elastic layer beneath the concrete slabs. The proposed model was then applied to compare the dynamic response of the innovative embedded rail track with respect to a conventional fastened slab track. The numerical results indicate that the innovative embedded rail track has advantages over the fastened slab track for its potentialities to reduce the dynamic wheel/rail force, the vibration level and deformation of the track parts, and the track defects and damages.
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Noufid, Abdelhamid, Nadia Hidar, Sougrati Belattar, Mohamed Elafi, and M’barek Feddaoui. "Thermal non-destructive characterization of rail networks by using Infrared Thermography and FEM simulation." MATEC Web of Conferences 360 (2022): 00014. http://dx.doi.org/10.1051/matecconf/202236000014.
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Because of the repeated passage of trains, anomalies are created inside the rails in the form of cracks of different shapes and position. These are due essentially to the wheel – rail contact. They present a hazard causing at the final stage rail failure, train derailment and accidents. Detecting track anomalies has become a major issue for the entire rail industry around the world. This paper focuses on the degradation of rails in urban railways in terms of cracks. The purpose is to develop an approach to detect and predict rail breaks, which will optimize maintenance task. Infrared thermography was used in order to characterise the effect of a defect on the acquired thermogram. Different defects were considered by varying their size, depth and inclination angle with respect to the rail surface.
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Bocz, Péter, Ákos Vinkó, and Zoltán Posgay. "A practical approach to tramway track condition monitoring: vertical track defects detection and identification using time-frequency processing technique." Selected Scientific Papers - Journal of Civil Engineering 13, s1 (March 1, 2018): 135–46. http://dx.doi.org/10.1515/sspjce-2018-0013.
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Abstract This paper presents an automatic method for detecting vertical track irregularities on tramway operation using acceleration measurements on trams. For monitoring of tramway tracks, an unconventional measurement setup is developed, which records the data of 3-axes wireless accelerometers mounted on wheel discs. Accelerations are processed to obtain the vertical track irregularities to determine whether the track needs to be repaired. The automatic detection algorithm is based on time–frequency distribution analysis and determines the defect locations. Admissible limits (thresholds) are given for detecting moderate and severe defects using statistical analysis. The method was validated on frequented tram lines in Budapest and accurately detected severe defects with a hit rate of 100%, with no false alarms. The methodology is also sensitive to moderate and small rail surface defects at the low operational speed.
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Orlov, Sergey P., Nikolai A. Efimushkin, and Natalia V. Efimushkina. "Deep neural network for diagnostics of railway track components." Vestnik of Samara State Technical University. Technical Sciences Series 30, no. 1 (June 16, 2022): 63–74. http://dx.doi.org/10.14498/tech.2022.1.4.
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The problem of increasing the speed of railway transportation and ensuring reliability is associated with constant monitoring of the condition of the railway tracks. The modern track measuring cars are equipped with video cameras and computer equipment for processing the received information. However, manual processing of data by operators in real-time is not possible. The article proposes a deep convolutional neural network for automatically recognizing and classifying defects in rail joints on rail track images. The rail video observation forms the image array during the passage of the track recording car. The formation of classes of rail joints is described. Regular rail joints with connectors, insulating joints, and welded joints are considered. Additional classes are identified, corresponding to various anomalous configurations of rail joints in the images. A modified structure of a pre-trained deep convolutional network is constructed. When preparing training samples, the actual images of rail joints were supplemented with artificial images obtained by affine transformations. The process of training and testing the classifier based on the developed convolutional network is described. The Transfer Learning is used to train the neural network. As a result of the experiments, the accuracy of classifying rail joints and detecting defects was at least 96%.
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Potapov, Dmitry, Volodymyr Vitolberg, Danylo Shumyk, Viacheslav Ovcharenko, and Viktor Bulgakov. "Reused rails for underground systems." MATEC Web of Conferences 230 (2018): 01013. http://dx.doi.org/10.1051/matecconf/201823001013.
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The structural components of the rail track, including rails, deteriorate in operation. However, some of them retain their operational characteristics and can be reused. This practice has found wide application on Ukrainian railways and shown a lot of self-evident advantages, among which the basic one is a rational use of material and technical means. Besides, development of a used rail system for underground railways may also optimize the track facility system for such specific conditions. The article presents results of the research into the change of the crumbling depth on the roll surface (the main rail defects of underground railways); it allowed the authors to conclude about the possibility to reuse rails for underground systems. Moreover, assessment of interacting forces in the wheel/rail system and the crumbling volume made it possible to determine rational application for used rails. The proposed system takes into account all the features of operating the railway track in underground systems, and also allows more efficient use of the residual rail resource without reducing the necessary level of traffic safety.
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Zhang, Ziwen, Mangui Liang, and Zhiyu Liu. "A Novel Decomposition Model for Visual Rail Surface Inspection." Electronics 10, no. 11 (May 26, 2021): 1271. http://dx.doi.org/10.3390/electronics10111271.
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Rail surface inspection plays a pivotal role in large-scale railway construction and development. However, accurately identifying possible defects involving a large variety of visual appearances and their dynamic illuminations remains challenging. In this paper, we fully explore and use the essential attributes of our defect structure data and the inherent temporal and spatial characteristics of the track to establish a general theoretical framework for practical applications. As such, our framework can overcome the bottleneck associated with machine vision inspection technology in complex rail environments. In particular, we consider a differential regular term for background rather than a traditional low-rank constraint to ensure that the model can tolerate dynamic background changes without losing sensitivity when detecting defects. To better capture the compactness and completeness of a defect, we introduce a tree-shaped hierarchical structure of sparse induction norms to encode the spatial structure of the defect area. The proposed model is evaluated with respect to two newly released Type-I/II rail surfaces discrete defects (RSDD) data sets and a practical rail line. Qualitative and quantitative evaluations show that the decomposition model can handle the dynamics of the track surface well and that the model can be used for structural detection of the defect area.
Dissertations / Theses on the topic "Rail track defects"
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Williams, M. D. "Rail surface geometry defects and track settlement /." Title page, table of contents and introduction only, 1994. http://web4.library.adelaide.edu.au/theses/09ENS/09ensw725.pdf.
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Fesharaki, Mohammad. "3-D Dynamic Analysis of High-Speed Railroad Track." FIU Digital Commons, 2017. http://digitalcommons.fiu.edu/etd/3366.
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High-Speed Rail (HSR) as a fast, reliable and environmentally friendly mode of transportation has received a lot of attention in recent decades. The International Union of Railways reported that there are more than 18600 miles of HSR in operation and about 1.6 billion passengers per year are carried by them. Although there are plans for HSR in many states including Florida, the United States, however, is still hesitant to develop its own HSR network. One of the main barriers to developing high-speed rail is excessive vibration propagation to the media which may cause annoyance to people who live in the track neighborhood. Train induced vibration also contributes to track settlement, developing track flaws, and increasing life cycle cost of track and supporting structures.
The aim of this research is to address this problem by conducting a comprehensive investigation into track dynamics. For this purpose, three-dimensional mass-spring-damper models of vehicle, track and supporting structures were developed and matrices of mass, stiffness, and damping of each subsystem were formed. The response of the whole system was, then, determined by coupling the subsystems using Hertz contact theory. The differential equations of the coupled system were solved by the Newmark integration method and the results including vertical and lateral displacements and forces were presented in the time domain. Since the purpose of this dissertation is to quantify the effect of track and vehicle condition on vibration level, rail defects were also taken into account and rail random irregularities for the vertical profile, Gauge, alignment and cross level (super elevation) were incorporated into a numerical solution. The results of the study show the effect of track and vehicle parameters on the response of the vehicle, track, and substructures.
Since Florida and some other states in the United States are very prone to hurricanes, an investigation was conducted into the effect of wind speed on vehicle stability. For this purpose, a curved beam was modeled to consider the influence of track curvature, cant deficiency, wind speed and train speed simultaneously. The results from the study show the maximum allowable values of train speed and axle load for different wind speeds. The findings can be used to decide under what circumstances there is a risk of vehicle overturning and how to avoid it.
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Bona, Melissa Ellen. "The effect of straightening and grinding of welds on track roughness." Thesis, Queensland University of Technology, 2005. https://eprints.qut.edu.au/16180/7/Thesis_Melissa_Bona.pdf.
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Rail is a very expensive component of the railway track. Therefore, research methods extending rail life have great economic importance. During the past thirty years and, particularly during the past ten years there has been an increasing awareness throughout most rail networks in the world of the need to introduce improved design criteria, better construction techniques and higher standard track generally. This implies that quality control at all levels is mandatory if these objectives are to be achieved.
With the improved understanding of degradation of track, a more complete comprehension of the costs associated with different operating and infrastructure conditions should also be developed, aiding in the determination of efficient maintenance costs and their contribution to access charges. Track and structures together account for 60% of maintenance costs, with 50% of the total being track. The UIC has done a lot of work on comparative performance indicators, and these show what potential savings much be out there for the taking, just by adopting current best practice. The old wisdom is that it's not enough o do things rights; we have to make sure that we do the right things.
These developments have largely resulted from the demand for higher speeds particularly in passenger services and the demand to accept heavier axle loads of freight traffic. Whilst the conventional railway track structure is not likely to change significantly over the next ten years there will be a requirement over that period for better quality track infrastructure. This means less rail surface defects, less internal defects and less wheels irregularities.
The presence of rail surface defects generally increases the roughness of the track leading to a poor passenger ride and increased safety risk with freight traffic. In addition, rail surface defects will generally increase the degradation rate of other track components; however, not all defects will produce visible track deterioration.
Dynamic impacts produced by the rollingstock running over rail surface defects, such as poor welds, will, over time, create continuous rail defects, loosening of fastenings, abrasion and skewing of sleepers, crushing of ballast and loss of formation geometry. It is only in the recent years that the importance of poor welds in track has been identified. Dips and peaks must be recognised as a severe track irregularity that needs to be addressed and removed.
Current maintenance activities have little effect on removing misaligned welds in track and the improvement obtained after the maintenance works is generally short lived. On the other hand, straightening operations have proven to solve the problem and maintain the results following 7 months of traffic.
As part of this project, a six kilometre test section was selected on the Mt Isa Line and all welds located in this region were monitored for over 9 months to increase the understanding of the effect of individual maintenance activities on the track roughness. Three 2km Divisions were established; each Division had different maintenance activities and levels of intervention completed over the duration of the project. Over 15,000 readings were recorded and analysed. The following conclusions were drawn.
The effect of cycle tamping was clearly identified when comparing the means of weld located in Division 1, 2 to the mean of welds in Division 3. Cycle tamping showed to have a significant positive effect on the dipped welds geometry and an increase in severity of peaked welds prior to their correction.
Straightening operations completed in Division 1 and 2 reduced the overall mean of weld misalignments. These Divisions were subjected to different levels of straightening intervention however they produced similar results. Division 1 all dips were straightened and Division 2 only dips >0.3mm were straightened. This means that no additional benefit, in terms of overall misalignment of welds, can be gained when straightening operations target dips with a misalignment smaller than 0.3mm.
Cycle grinding proved to have little effect on the removal of both dips and peaks. In fact, due to the configuration of the grinding machine, grinding operation produced a slight worsening of the dips misalignments and only a minor improvement of peaks.
Although long term monitoring of the site may show minor variations in weld geometry performance, after approximately 3.9 Mgt of traffic the mean of dipped welds in Division 1 and 2 appeared to remain unaltered, as Division 3 showed a minor worsening. Furthermore, the mean of peaked welds in Division 1 and 2 appeared to remain unaltered, as Division 3 showed a minor worsening.
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Bona, Melissa Ellen. "The effect of straightening and grinding of welds on track roughness." Queensland University of Technology, 2005. http://eprints.qut.edu.au/16180/.
Full textAbstract:
Rail is a very expensive component of the railway track. Therefore, research methods extending rail life have great economic importance. During the past thirty years and, particularly during the past ten years there has been an increasing awareness throughout most rail networks in the world of the need to introduce improved design criteria, better construction techniques and higher standard track generally. This implies that quality control at all levels is mandatory if these objectives are to be achieved. With the improved understanding of degradation of track, a more complete comprehension of the costs associated with different operating and infrastructure conditions should also be developed, aiding in the determination of efficient maintenance costs and their contribution to access charges. Track and structures together account for 60% of maintenance costs, with 50% of the total being track. The UIC has done a lot of work on comparative performance indicators, and these show what potential savings much be out there for the taking, just by adopting current best practice. The old wisdom is that it's not enough o do things rights; we have to make sure that we do the right things. These developments have largely resulted from the demand for higher speeds particularly in passenger services and the demand to accept heavier axle loads of freight traffic. Whilst the conventional railway track structure is not likely to change significantly over the next ten years there will be a requirement over that period for better quality track infrastructure. This means less rail surface defects, less internal defects and less wheels irregularities. The presence of rail surface defects generally increases the roughness of the track leading to a poor passenger ride and increased safety risk with freight traffic. In addition, rail surface defects will generally increase the degradation rate of other track components; however, not all defects will produce visible track deterioration. Dynamic impacts produced by the rollingstock running over rail surface defects, such as poor welds, will, over time, create continuous rail defects, loosening of fastenings, abrasion and skewing of sleepers, crushing of ballast and loss of formation geometry. It is only in the recent years that the importance of poor welds in track has been identified. Dips and peaks must be recognised as a severe track irregularity that needs to be addressed and removed. Current maintenance activities have little effect on removing misaligned welds in track and the improvement obtained after the maintenance works is generally short lived. On the other hand, straightening operations have proven to solve the problem and maintain the results following 7 months of traffic. As part of this project, a six kilometre test section was selected on the Mt Isa Line and all welds located in this region were monitored for over 9 months to increase the understanding of the effect of individual maintenance activities on the track roughness. Three 2km Divisions were established; each Division had different maintenance activities and levels of intervention completed over the duration of the project. Over 15,000 readings were recorded and analysed. The following conclusions were drawn. The effect of cycle tamping was clearly identified when comparing the means of weld located in Division 1, 2 to the mean of welds in Division 3. Cycle tamping showed to have a significant positive effect on the dipped welds geometry and an increase in severity of peaked welds prior to their correction. Straightening operations completed in Division 1 and 2 reduced the overall mean of weld misalignments. These Divisions were subjected to different levels of straightening intervention however they produced similar results. Division 1 all dips were straightened and Division 2 only dips >0.3mm were straightened. This means that no additional benefit, in terms of overall misalignment of welds, can be gained when straightening operations target dips with a misalignment smaller than 0.3mm. Cycle grinding proved to have little effect on the removal of both dips and peaks. In fact, due to the configuration of the grinding machine, grinding operation produced a slight worsening of the dips misalignments and only a minor improvement of peaks. Although long term monitoring of the site may show minor variations in weld geometry performance, after approximately 3.9 Mgt of traffic the mean of dipped welds in Division 1 and 2 appeared to remain unaltered, as Division 3 showed a minor worsening. Furthermore, the mean of peaked welds in Division 1 and 2 appeared to remain unaltered, as Division 3 showed a minor worsening.
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Pecile, Bérénice. "Modèle dynamique d'interaction véhicule-voie ferroviaire en présence de défauts géométriques sur les surfaces en contact." Thesis, Valenciennes, 2017. http://www.theses.fr/2017VALE0004/document.
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Les phénomènes dynamiques observés lors de la circulation des trains provoquent des nuisances, notamment sonores et vibratoires, qui sont amplifiées par la présence de défauts sur la roue et sur le rail. Pour les analyser, il est nécessaire de prédire avec robustesse le comportement dynamique des composants impliqués dans l’interaction véhicule-voie et donc de simuler les efforts de contact générés pour des interfaces non idéalisées.L’objectif de cette thèse est donc de proposer un modèle semi-analytique global compatible avec l’intégration de multiples défauts géométriques sur les surfaces en contact. Afin de simuler l’interaction véhicule-voie dans le domaine temporel et garantir une applicabilité en phase de dimensionnement, une attention particulière est portée sur le compromis entre la précision des résultats et les temps de calcul associés.Le modèle ainsi proposé est composé d’un demi-bogie, dont le comportement vertical est représenté par un ensemble de masses-ressorts-amortisseurs, circulant sur une voie ballastée. Cette dernière est assimilée à une poutre bi-appuyée, supportée périodiquement à l’emplacement des traverses. Ces deux systèmes sont couplés en contact grâce à une procédure Distributed Point Reacting Spring (DPRS) sous forme discrétisée.Une validation du modèle est, d’une part, proposée en considérant des travaux antérieurs dans le cas de géométries parfaites. D’autre part, de multiples combinaisons de défauts, localisés comme le méplat ou répartis comme l’usure ondulatoire, sont introduites dans la simulation. La variabilité spatiale, particulière au cas de l’écaillage, est modélisée par des champs aléatoiresThe appearance of dynamic phenomena during the running of train on track leads to issues such as noise and vibration pollution, which can be further amplified by the presence of defects on the treads. In order to analyze them, it is necessary to predict with reliability the dynamic behavior of the vehicle-track interaction components, in particular the contact forces produced by non perfect treads.The aim of this PhD thesis is to provide a semi-analytical vehicle-track interaction model able to take into account multiple defects on the surfaces in contact. In order to conduct simulations in the time-domain and ensure applicability in the sizing phase, a special attention is given on the compromise between the accuracy of the results and the simulation times.The proposed model is therefore composed of half a bogie running on a ballasted track. This latter is modeled by a pinned-pinned beam with periodic supports located at the sleepers while the vertical behavior of the bogie is given by masses, springs and dampers. These two models are coupled in contact by a discretized Distributed Point Reacting Spring (DPRS) procedure.A validation of the model, based on previous work, is firstly proposed for perfect treads. Then, multiple combinations of defects, either localised as wheelflat or spread as corrugation, are introduced in the simulation. The spatial variability, specific to shelling, is modeled by random fields
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Basson, Conrad Charl Peter. "Analysis of defects occuring on rail tracks." Thesis, Cape Peninsula University of Technology, 2018. http://hdl.handle.net/20.500.11838/2752.
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Thesis (Master of Engineering in Mechanical Engineering)--Cape Peninsula University of Technology, 2018.South Africa’s railway system is the most highly developed in Africa. There are different kinds of transport systems in South Africa but rail transport is considered as one of an important element of the country’s transport infrastructure. In South Africa, over 2.4 million passengers make use of rail transport to get them to their destinations. However, evidence shows that train accidents have become a common occurrence across the country. Train-related accidents such as collision, derailments, platform change incidents and commuter accidents, cost South Africa over R400 million per year. The analysis of derailments indicates that the most significant single contributor to derailments is rail breaks. This contrasts considerably with prescribed relevant local and international benchmarks, which show a much lower percentage of derailments due to rail break. The frequency of derailments due to rail breaks in South Africa seems to be higher in the northern than the southern region. Furthermore, the proportion of rail breaks that result in derailment is considerably higher than the set benchmarks and therefore, if there is a rail break, then the probability of this translating into a derailment is astonishingly high. Equally, the high incidence of derailments due to rail breaks is affected by the train length and axle load and further exacerbated by the absence of track circuitry. Since derailments are a direct function of the incidence of rail breaks, focus is required to characterize the factors causing defects on rail lines. This study investigated steel rail material by characterising the piece of the damaged rail with the aim to gain a better understanding of the wear mechanism. Chemical composition analysis of steel rail sample was conducted with the use of a Scanning Electron microscopy. Hardness of steel rail was measured with a Vickers hardness tester. An Optical Microscopy was used to examine the microstructure features of the worn rail samples. This study discovered that the worn out rail, which was produced from high carbon steel with pearlite and ferrite microstructure, undergoes decarburization and a plastic deformation process. The decarburization process happens when the rail track is heated to 700 oC and above when the carbon atoms at the surface interact with the atmospheric gases and are removed from the steel as a gaseous phase. Plastic deformation is created when the iron atoms are heated above the elastic point resulting in the permanent movement of iron atoms.
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Babenko, Pavel. "VISUAL INSPECTION OF RAILROAD TRACKS." Doctoral diss., University of Central Florida, 2009. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4013.
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In this dissertation, we have developed computer vision methods for measurement of rail gauge, and reliable identification and localization of structural defects in railroad tracks. The rail gauge is the distance between the innermost sides of the two parallel steel rails. We have developed two methods for evaluation of rail gauge. These methods were designed for different hardware setups: the first method works with two pairs of unaligned video cameras while the second method works with depth maps generated by paired laser range scanners. We have also developed a method for detection of rail defects such as damaged or missed rail fasteners, tie clips, and bolts, based on correlation and MACH filters. Lastly, to make our algorithms perform in real-time, we have developed the GPU based library for parallel computation of the above algorithms. Rail gauge is the most important measurement for track maintenance, because deviations in gauge indicate where potential defects may exist. We have developed a vision-based method for rail gauge estimation from a pair of industrial laser range scanners. In this approach, we start with building a 3D panorama of the rail out of a stack of input scans. After the panorama is built, we apply FIR circular filtering and Gaussian smoothing to the panorama buffer to suppress the noise component. In the next step we attempt to segment the rail heads in the panorama buffer. We employ the method which detects railroad crossings or forks in the panorama buffer. If they are not present, we find the rail edge using robust line fit. If they are present we use an alternative way: we predict the rail edge positions using Kalman filter. In the next step, common to both fork/crossings conditions, we find the adjusted positions of rail edges using additional clustering in the vicinity of the edge. We approximate rail head surface by the third degree polynomial and then fit two plane surfaces to find the exact position of the rail edge. Lastly, using rail edge information, we calculate the rail gauge and smooth it with 1D Gaussian filter. We have also developed a vision-based method to estimate the rail gauge from a pair of unaligned high shutter speed calibrated cameras. In this approach, the first step is to accurately detect the rail in each of the two non-overlapping synchronous images from the two cameras installed on the data collection cart by building an edge map, and fitting lines into the edge map using the Hough transform, and detecting persistent edge lines using a history buffer. After railroad track parts are detected, we segment rails out to find rail edges and calculate the rail gauge. We have demonstrated how to apply Computer Vision methods (the correlation filters and MACH filters in particular) to find different types of railroad elements with fixed or similar appearance, like railroad clips, bolts, and rail plates, in real-time. Template-based approaches for object detection (correlation filters) directly compare gray scale image data to a predefined model or template. The drawback of the correlation filters has always been that they are neither scale nor rotation invariant, thus many different filters are needed if either scale or rotation change. The application of many filters cannot be done in real-time. We have succeeded to overcome this difficulty by using the parallel computation technology which is widely available in the GPUs of most advanced graphics cards. We have developed a library, MinGPU, which facilitates the use of GPUs for Computer Vision, and have also developed a MinGPU-based library of several Computer Vision methods, which includes, among others, an implementation of correlation filters on the GPU. We have achieved a true positive rate of 0.98 for fastener detection using implementation of MACH filters on GPU. Besides correlation filters, MinGPU include implementations of Lucas-Kanade Optical Flow, image homographies, edge detectors and discrete filters, image pyramids, morphology operations, and some graphics primitives. We have shown that MinGPU implementation of homographies speeds up execution time approximately 600 times versus C implementation and 8000 times versus Matlab implementation. MinGPU is built upon a reusable core and thus is an easily expandable library. With the help of MinGPU, we have succeeded to make our algorithms work in real-time.Ph.D.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Computer Science PhD
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Semprebone, Paula da Silva. "Desgastes em trilhos ferroviarios : um estudo teorico." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/258211.
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Orientador: Cassio Eduardo Lima de PaivaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
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Resumo: O assunto a ser abordado nesta pesquisa refere-se ao componente da superestrutura ferroviária trilho, especificamente aos defeitos que nele se verificam em conseqüência de sua utilização como guia para o material rodante e transmissor de esforços decorrentes do movimento do veículo, e do desgaste do contato roda-trilho. A importância de se realizar este estudo fundamenta-se na necessidade de se conhecer detalhadamente os defeitos e o limite de desgaste do trilho, que permitem determinar sua vida útil, para que se possa evitar ao máximo sua substituição, devido ao alto custo envolvido, além da questão da segurança da via que, dependendo do defeito, pode ser comprometida. Para a realização do trabalho foi realizada uma pesquisa bibliográfica, objetivando reunir informações sobre o assunto e levantar dissertações existentes que buscam solucionar tais problemas. Busca-se, ainda, encontrar uma justificativa para o valor limite de desgaste adotado atualmente no meio ferroviário, que corresponde a 25% de perda em área do boleto do trilho, através de simulações do desgaste utilizando-se um modelo computacional, além de rotinas de cálculo que permitam verificar se esse parâme1rO é restrição do . ponto de vista do dimensionamento do trilho. Pretende-se, assim, a1ravés desta pesquisa proporcionar uma contribuição ao meio ferroviário, avaliando-se se o limite de desgaste adotado mos1ra-se adequado à realidade ferroviária
Abstract: The matters concerned in this research particularly refer to damages caused by stress while using tracks on permanent railways as guide and strain transmitter of the vehicles. Importance is attached to this study based on the need of understanding deep and in detail the faults and wear limits on the tracks, which allow determining its period of use, so that substitution may be avoided due to its high costs. Furthermore, the railway safety may be weaknessed depending on the sort of wear. This study has basis on a bibliographical research aiming to gather information and possible works on this field in order to solve the problems mentioned above, as well as finding proofs for the current wear rate accepted in the railway field, which is 25% of track area decrease, throughout wear simulations on a computer based model, besides calculations which allow stating whether this standard depends on the track size. This work claims to contribute to the railway field evaluating if the adopted wear rate meets our railway reality
Mestrado
Transportes
Mestre em Engenharia Civil
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(9776303), Shah Nafis Ahmad. "Analysis of a very low tare mass wagon concept for intermodal freight." Thesis, 2018. https://figshare.com/articles/thesis/Analysis_of_a_very_low_tare_mass_wagon_concept_for_intermodal_freight/13408622.
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The empty weight or tare load of railway freight wagons is significant compared to the gross load (13-43% of the gross load) which not only reduces the possibility of carrying a higher payload but also increases the energy consumption per payload tonne hauled. One way to reduce the energy consumption per tonne payload is to reduce the tare load. One possibility of lowering the tare load is to reduce the number of components such as a bolster, sideframes, and axles. A two-axle wagon compared to a bogied wagon creates a possibility to reduce tare by up to 4-5t on a two-axle configuration. The fewer components on a two-axle wagon, however, result in inferior dynamic performance such as low critical hunting speed, poor curving ability, greater vehicle response to short irregularities etc, so, in spite of having low tare, the two-axle wagons are not as popular as the bogied wagons.
To take advantage of the lower tare mass of a two-axle wagon, a new concept wagon was conceptualised as a wagon with maximum axle load (~41 tonnes) and with enough load space to ensure a 80 tonne gross mass. The developed concept resulted in a wagon with a deck length of ~19.8m that allows carrying three 20’, or a 20’ and a 40’, or a 65’ container. The axle spacing (13.8m), overhang length (3m), tare mass (8t) and gross mass (80t) of the developed concept wagon is considerably different to the normal two-axle wagon. The challenge then was to design a suspension that would pass dynamics and roadworthiness tests.
It was reasoned that as the developed concept wagon was a new and radical concept, a more rigorous test approach to dynamic testing should be added to the normal tests and acceptance parameters in railway standards. A more rigorous test approach was developed which included consideration of test track defect lengths based on bogie centre distance (BCD) and resonance conditions for the cyclic track defects. The consideration of resonance condition requires developing equivalent amplitudes of track defects corresponding to the wavelengths in the track which are multiples of bogie centre distance for the cyclic bounce, pitch and roll track defects.
Using the more rigorous testing regime an innovative axle suspension was developed and refined to a design with three stages consisting of a conventional leaf spring, and the UIC link suspension in series with two multi-stage coil springs. It was also necessary to add longitudinal stiffness to improve axle yaw stability and hunting speed. The resulting design showed excellent stability with a critical speed of 204km/h and the multi-stage suspension allowed for negotiation of isolated lateral, vertical and long twist track defects as per AS7509 up to the defect band F of the ARTC track geometry standard. The short twist tests were however problematic. The resultant concept requires a smaller short twist track defect limit (8mm over 2m) than the defect band G of ARTC track geometry standard. The developed concept performed satisfactorily on track spectra up to FRA class 6 track.
Finally, the energy consumption of the developed wagon concept was evaluated and compared with similar capacity wagons such as RQTY, sgns60 and double stack container wagons in a train simulation. The energy saving ranged from 6 to 12% across various operating scenarios.
Books on the topic "Rail track defects"
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Board, United States National Transportation Safety. Railroad accident report: Rear end collision between Boston and Main [sic] Corporation commuter train no. 5324 and Consolidated Rail Corporation train TV-14, Brighton, Massachusetts, May 7, 1986. Washington, D.C: The Board, 1987.
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United States. National Transportation Safety Board. Railroad accident report: Rear end collision between Boston and Main [sic] Corporation commuter train no. 5324 and Consolidated Rail Corporation train TV-14, Brighton, Massachusetts, May 7, 1986. Washington, D.C: The Board, 1987.
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Board, United States National Transportation Safety. Railroad accident report: Rear-end collision of Amtrak passenger train 94, the Colonial, and Consolidated Rail Corporation freight train ENS-121, on the Northeast Corridor, Chase, Maryland, January 4, 1987. Washington, D.C: National Transportation Safety Board, 1988.
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United States. National Transportation Safety Board. Railroad accident report: Rear-end collision of Amtrak passenger train 94, the Colonial, and Consolidated Rail Corporation freight train ENS-121, on the Northeast Corridor, Chase, Maryland, January 4, 1987. Washington, D.C: National Transportation Safety Board, 1988.
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Board, United States National Transportation Safety. Highway accident report: Intercity bus loss of control and collision with bridge rail on Interstate 70 near Frederick, Maryland, August 25, 1985. Washington, D.C: The Board, 1987.
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United States. National Transportation Safety Board. Highway accident report: Intercity bus loss of control and collision with bridge rail on Interstate 70 near Frederick, Maryland, August 25, 1985. Washington, D.C: The Board, 1987.
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United States. National Transportation Safety Board. Highway accident report: Intercity bus loss of control and collision with bridge rail on Interstate 70 near Frederick, Maryland, August 25, 1985. Washington, D.C: The Board, 1987.
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United States. National Transportation Safety Board. Railroad accident report: Head-on collision of Chicago, Shore and South Bend railroad trains nos. 123 and 218, Gary, Indiana, January 21, 1985. Washington, D.C: The Board, 1985.
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Board, United States National Transportation Safety. Railroad accident report: Derailment of Amtrak passenger train no. 60, the Montrealer, on the Central Vermont Railway near Essex Junction, Vermont, July 7, 1984. Washington, D.C: The Board, 1986.
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United States. National Transportation Safety Board. Railroad accident report: Rear end collision of two Chicago Transit Authority trains near the Montrose Avenue Station, Chicago, Illinois, August 17, 1984. Washington, D.C: The Board, 1985.
Find full textBook chapters on the topic "Rail track defects"
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Xu, Yunhua, Xuejun Wang, and Shuyuan Li. "Track Surface Defect Detection Based on EfficientDet." In Proceedings of the 5th International Conference on Electrical Engineering and Information Technologies for Rail Transportation (EITRT) 2021, 56–66. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-9909-2_7.
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Fang, Enquan, Kunshan Yang, and Ming Zeng. "Track Defect Recognition Algorithm Based on Deep Learning." In Proceedings of the 5th International Conference on Electrical Engineering and Information Technologies for Rail Transportation (EITRT) 2021, 397–408. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-9913-9_45.
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Wooh, Shi-Chang, and Arthur Clay. "High-Speed Monitoring of Surface Defects in Rail Tracks Using Ultrasonic Doppler Effect." In Review of Progress in Quantitative Nondestructive Evaluation, 1681–88. Boston, MA: Springer US, 1998. http://dx.doi.org/10.1007/978-1-4615-5339-7_218.
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Rostami, Javad, Faeez Masurkar, Peter Tse, Nitesh Yelve, and Edison Z. Y. Hou. "An Adaptive Wavelet Library to Detect Surface Defects in Rail Tracks Using a Laser Ultrasonic System." In Lecture Notes in Civil Engineering, 181–89. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-64594-6_19.
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Moridpour, Sara, Ehsan Mazloumi, and Reyhaneh Hesami. "Application of Artificial Neural Networks in Predicting the Degradation of Tram Tracks Using Maintenance Data." In Deep Learning and Neural Networks, 845–64. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-7998-0414-7.ch047.
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The increase in number of passengers and tramcars will wear down existing rail structures faster. This is forcing the rail infrastructure asset owners to incorporate asset management strategies to reduce total operating cost of maintenance whilst improving safety and performance. Analysing track geometry defects is critical to plan a proactive maintenance strategy in short and long term. Repairing and maintaining the correctly selected tram tracks can effectively reduce the cost of maintenance operations. The main contribution of this chapter is to explore the factors influencing the degradation of tram tracks (light rail tracks) using existing geometric data, inspection data, load data and repair data. This chapter also presents an Artificial Neural Networks (ANN) model to predict the degradation of tram tracks. Predicting the degradation of tram tracks will assist in understanding the maintenance needs of tram system and reduce the operating costs of the system.
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Iwand, Hans, and Joel Hassebrock. "Failure Analysis of Railroad Components." In Analysis and Prevention of Component and Equipment Failures, 754–77. ASM International, 2021. http://dx.doi.org/10.31399/asm.hb.v11a.a0006837.
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Abstract Because of the tough engineering environment of the railroad industry, fatigue is a primary mode of failure. The increased competitiveness in the industry has led to increased loads, reducing the safety factor with respect to fatigue life. Therefore, the existence of corrosion pitting and manufacturing defects has become more important. This article presents case histories that are intended as an overview of the unique types of failures encountered in the freight railroad industry. The discussion covers failures of axle journals, bearings, wheels, couplers, rails and rail welds, and track equipment.
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Juan Carlos, Jauregui-Correa. "Predicting Vehicle-Track Interaction with Recurrence Plots." In Vibration Monitoring and Analysis - Recent Advances [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.105752.
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This chapter presents a method for identifying the dynamic response of vehicles (railcars) running on a rail track. The method is based on the recurrence plots developed from the phase diagram (phase plane). The phase plane is constructed using Hamilton’s principle for a single-mass system. The state variables are estimated from acceleration measurements registered in an experimental test rig. The measurements were recorded with accelerometers and gyroscopes mounted on the railcar that circulated on a closed-loop track. The acceleration data were integrated using the empirical mode decomposition method and the time delay principle. The acceleration data were separated into two data vectors: rigid body motion and vibration modes. The recurrence plots were built for both data vectors, and it was found that the vibration modes were more sensitive to track defects and curvature changes. The recurrence plots were analyzed with the recurrence quantification analysis, and it was found that the Recurrence Plots can determine the location and type of defects.
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P. Boronenko, Yuri, Rustam V. Rahimov, and Waail M. Lafta. "New Approach Measuring the Wheel/Rail Interaction Loads." In Railway Transport Planning and Management [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.100031.
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This chapter suggested new methods for monitoring the dynamic processes of rolling stock/rail interaction. This study develops a new technical solution for measuring the wheel/rail interaction forces on a significant part of the sleeper. The theoretical part of this study, using FEM, confirm the ability of piecewise continuous recording of vertical and lateral forces from the wheel/rail interaction by measuring the stresses in two sections of the rail. Also, the optimum location of strain gauges and the effective length of the measuring zone have been determined. The experimental part of this study has been carried out on the stands and the railway track to confirm the effectiveness of the method to determine the vertical and lateral wheel/rail interaction forces, increase the reliable statistical data, improve the measurement accuracy, reducing the time and cost compared with current testing methods. The developed method is recommended to determine the wheel/rail interaction forces and identify defects on the wheels when diagnosing rolling stock on operational and travel regimes.
Conference papers on the topic "Rail track defects"
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Pucillo, Giovanni Pio. "On the Effects of Multiple Railway Track Alignment Defects on the CWR Thermal Buckling." In 2018 Joint Rail Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/jrc2018-6205.
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The lateral stability of the continuous welded rail (CWR) depends on a number of parameters which contribute to the progressive loss of the initial alignment of the track and its consequent predisposition to deform sideways, gradually or sharply, with serious risks for the safety both of passengers and operators. Different types of initial lateral defect, in terms of shape and size, are introduced by many authors in their own numerical and analytical model, but essentially all of them can be traced back — except for small “personalizations” — to the model proposed by Andrew Kish, who hypothesized the existence of a misalignment defect having the shape of a sine curve extended for half-wavelength, characterized by amplitude and wavelength values typical of the USA railroads. Moreover, all previous studies focused their attention on the introduction, in a geometrically perfect railway track, of a single defect confined in a zone of finite dimensions and having a rather simple geometry which qualitatively approximates the real defect, with the aim of simplifying the calculation of the buckling temperatures of the track associated with such geometry. In this paper, it was preliminarily analyzed the way the defect introduced in the track affects the critical temperature values. It started with a defect created artificially, applying to a geometrically perfect track and in the absence of thermal loads, a lateral displacement in the central transversal section of the track, and calculating, with the hypothesis of linear elastic behavior, the resulting deformed shape, which was assumed, after zeroing the corresponding stress field, as the input geometry for the subsequent buckling calculation. The deformed shape so obtained, being a Zimmermann deformed shape type, has no geometrical discontinuities near the defect and interprets in a natural way the defected geometry of the track, due to the dependence of its configuration on the flexural stiffness of the entire track in the lateral plane. Afterwards, modeling was carried out taking into account the real behavior of the track after the loss of its rectilinear configuration: the defect was created simulating the response of the track to a momentary lateral load — resulting, e.g., from train passages — which succeeded to cause a permanent displacement resulting from the elastic-plastic response of the track. The deformed shape of the track obtained in this way was used as the input geometry for the calculation of the buckling temperatures, once without resetting the stress field induced in the structure by the loading–unloading hysteresis cycle, and then considering the track free from internal stresses. The results show that both the numerical model that contemplate the defect introduced “plastically”, and that where the track is free from internal stresses, lead to more conservative results against the risk of thermal buckling in railway tracks made with CWR. A better approximation of the realistic representation of a generic defected railway track was pursued considering an indefinite number of defects distributed along the track, where each defect was characterized by different amplitude and wavelength values. The obtained results show that the presence of multiple defects further reduces the safety factor against the thermal track buckling phenomenon. The paper ends with the proposal of an evaluation criterion that takes into account the effects of multiple alignment defects on the critical buckling temperatures in continuous welded rail tracks.
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Takami, Kuya, Saied Taheri, Mehdi Taheri, and Tomonari Furukawa. "Prediction of Railroad Track Foundation Defects Using Wavelets." In 2013 Joint Rail Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/jrc2013-2456.
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This paper presents a novel technique that utilizes wavelet analysis to identify and predict the defects in railroad foundations and rails to prevent derailment or other damages. The proposed defect detection algorithm eliminates the use of wheel and/or track monitoring systems, which are expensive and time inefficient. The algorithm has been validated for the rail crack prediction using only vertical accelerometer signal which accurately detects impending rail breakage while distinguishing the signal generated by special track components such as rail joins and switches. Since the algorithm is flexible, further development can be tailored to detect significantly different rail defects such as track shift and other rail foundation defects. The algorithm is further improved by incorporating SIMPACK dynamic simulation to assist classification of the acceleration signatures. The actual data was then compared to simulation in order to validate the effectiveness of the algorithm.
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Wu, Qing, Colin Cole, and Maksym Spiryagin. "Track Maintenance Reactions for Combined Track Defects." In Second International Conference on Rail Transportation. Reston, VA: American Society of Civil Engineers, 2022. http://dx.doi.org/10.1061/9780784483886.002.
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Hu, Can, and Xiang Liu. "Modeling Track Geometry Degradation Using Support Vector Machine Technique." In 2016 Joint Rail Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/jrc2016-5739.
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Analyzing track geometry defects is of crucial importance for railway safety. Understanding when a defect will need to be repaired can help in both planning a preventive maintenance schedule and reducing the probability of track failures. This paper discusses the data cleaning and analysis processes for modeling track geometry degradation. An analytical data model named the Support Vector Machine (SVM) was developed to model the deterioration of track geometry defects. This paper mainly focuses on the following three defect types — surface, cross level and dip. The model accounts for traffic volume, defect amplitude, track class, speed and other potential factors. Results demonstrate that the proposed analytical data model can have a prediction accuracy above 70%.
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Pucillo, Giovanni Pio. "Train-Induced Load Effects on the Thermal Track Buckling." In 2019 Joint Rail Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/jrc2019-1276.
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Thermal track buckling is probably the major problem due to the advent of continuous welded rail track. In fact, when the rails temperature rises over a critical value, the track can buckle, suddenly or progressively, in the lateral plane. Both poor ballast conditions and large lateral alignment defects are the principal causes of such phenomenon. In a previous paper, a parametric finite element model for thermal track buckling simulation was presented and validated by comparison with analytical results of the literature. In this study, the finite element model has been further validated by comparison with analytical and numerical results obtained by three other authors. Moreover, to take into account the effect on the buckling temperatures of the vertical loads due to train passes, the tie-ballast lateral resistance has been modified along the track, taking into account the vertical reaction forces distribution induced by axle loads. A sensitivity analysis has been carried out both for tangent and curved track, considering two values of the alignment defect amplitude, and different values of the parameters that characterize actual railway vehicles. It is found that the conditions to trigger progressive buckling (△Tmax ≈ △Tmin) are attained with small values of the truck center distance, and in a more accentuated manner in the presence of high values of the lateral alignment defect. △Tmax and △Tmin increase with axle spacing, and this increase is more pronounced for low values of the truck center spacing. △Tmax and △Tmin also increase with curve radius, but decrease for increasing values of the misalignment defect amplitude. In explosive buckling conditions (△Tmax ≠ △Tmin), there is a limit value of the truck center distance above which the vertical load has no more effects, and the results of the static thermal buckling are found.
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Hopkins, Brad M., and Saied Taheri. "Track Health Monitoring Using Wavelets." In ASME 2010 Rail Transportation Division Fall Technical Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/rtdf2010-42004.
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This paper presents a defect detection algorithm for rail health monitoring that could potentially be used with limited bogie. Current wheel and track monitoring requires expensive track instrumentation and/or time consuming operation of railway monitoring vehicles. The proposed health monitoring algorithm can potentially be used with a portable data acquisition system that can be relocated from train to train to monitor and diagnose the conditions of the track as a train is driven during typical day-to-day operation. The algorithm processes the data using wavelets and is able to locate defects and provide information that may help to distinguish between various types of rail defects. In recent years, wavelets have been used extensively in signal processing because of their ability to analyze a signal simultaneously in the time and frequency domains. The Fourier transform has been used traditionally in signal processing to locate dominant frequencies in a signal, but it is unable to provide time localization of those frequencies. Unlike the Fourier transform, the wavelet transform uses a set of basis functions with finite energy, which is advantageous for detecting the irregular events that may show up in a transient signal. The wavelets used in the proposed signal processing routine were chosen for optimal signal decomposition through consideration of the signals that are likely to be generated from common rail and wheel defects, including rail cracks, squats, corrugation, and, wheel out-of-rounds. A sample accelerometer signal was generated from information found in existing literature and was then processed using the proposed defect detection algorithm. Results show the potential of this algorithm to locate and diagnose defects from limited bogie vertical acceleration data. This study is intended to present a proof-of-concept for the proposed defect detection algorithm, providing a basis for which a more comprehensive defect detection and diagnosis algorithm can be developed.
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Roghani, Alireza, Renato Macciotta, and Michael Hendry. "Combining Track Quality and Performance Measures to Assess Track Maintenance Requirements." In 2015 Joint Rail Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/jrc2015-5654.
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The serviceability of a section of railway highly depends on track stiffness and roughness. Railway operators regularly measure parameters associated with track stiffness and roughness to evaluate the track conditions. These measures are used in combination with performance observations to assess maintenance requirements. Although these assessments are mostly qualitative, railway operations have benefited from them. Railway operators keep comprehensive records of different types of track defects along their lines. These records are a measure of track performance and present an opportunity to quantify the relationship between track quality and performance. This brings the possibility of developing a performance-based approach for assessing the maintenance requirement along a railway track. In this paper, a database of track geometry defects along Canadian National Railway’s Lac la Biche subdivision (Alberta) has been compared against measured parameters associated with track roughness and stiffness. The analyses confirm the relationship between track stiffness and roughness, and the occurrence of track defects. This relationship is further used to define threshold values of track roughness and stiffness, and a hazard chart for maintenance requirements along the Lac la Biche subdivision is proposed.
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Li, Shaoguang, Alfredo Núñez, Zili Li, and Rolf Dollevoet. "Automatic Detection of Corrugation: Preliminary Results in the Dutch Network Using Axle Box Acceleration Measurements." In 2015 Joint Rail Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/jrc2015-5730.
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Short pitch corrugation is commonly seen in all kinds of tracks. There is not yet a conclusive explanation in the literature for its initiation and growth mechanisms. In this paper, we use an axle box acceleration (ABA) measurement system to detect corrugation. ABA can be easily implemented in operational trains, providing direct and reliable health monitoring of the track. We have extended a detection algorithm for rail surface local short wavelength defects to also detect short pitch corrugation, which is a continuous defect over the track. A 3D transient FE wheel-track model is employed to find theoretical signature tunes of the wheel-track system response when passing over a short pitch corrugation. Numerical simulations agree with ABA measurement obtained in the Dutch rail network. Based on the signature tune identified, an automatic detection algorithm is developed. Preliminary results with the algorithm are discussed. Field observations show a good potential of the detection algorithm to be used by inframanagers, to detect and monitor corrugation.
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Afzalan, Milad, Farrokh Jazizadeh, and Mehdi Ahmadian. "Toward Railway Automated Defect Detection From Onboard Data Using Deep Learning." In 2020 Joint Rail Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/jrc2020-8031.
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Abstract Regular monitoring of railway systems is imperative for improving safety and ride quality. To this end, data collection is carried out regularly in the rail industry to document performance and maintenance. The use of machine learning methods in the past recent years has provided opportunities for improved data processing and defect detection and monitoring. Such methods rely on installing instrumentation wayside or collecting data from onboard rolling stock. Using the former approach, only specific locations can be monitored, which could hinder covering a large territory. The latter, however, enables monitoring large sections of track, hence proving far more spatial efficiency. In this paper, we have investigated the feasibility of rail defect detection using deep learning from onboard data. The source of data is acceleration and track geometry collected from onboard railcars. Such an approach allows collecting a large set of data on a regular basis. A long short-term memory (LSTM) architecture is proposed to examine the measured time-series to flag potential track defects. The proposed architecture investigates the characteristics of time-series signatures during a short time (∼ls) and classifies the associated track segment to normal/defect states. Furthermore, a novel automated labeling method is proposed to parse the exception report data (recorded by the maintenance team) and label defects for associated time-series signatures during the training phase. In a pilot study, field data from a revenue service Class I railroad has been used to evaluate the proposed deep learning method. The results show that it is possible to efficiently analyze the data (collected onboard a railcar operated in revenue service) for automated defect detection, with relatively higher accuracy for FRA type I defects.
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He, Jiabo, Tal Ben-Gera, and Xiang Liu. "Risk Analysis of Freight-Train Derailment Caused by Track Geometry Defect." In 2016 Joint Rail Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/jrc2016-5743.
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This paper develops an analytical framework for analyzing freight-train derailment risk due to track geometry failures. First, track geometry degradation is estimated based on a previous study that uses data from one Class I railroad. Then, the frequency of expected number of track-geometry-defect-caused derailment on mainlines is estimated. After that, the derailment severity (measured by the number of railcars derailed) can be predicted based on FRA-reportable track-geometry-failure-caused freight-train derailments. Due to data limitations, several simplifying assumptions were made to illustrate model structure and implementation procedure. The model can be adapted to specific carriers and locations for normative risk management of track geometry defects.