Artículos de revistas: "Railway, wear, rolling contact fatigue, corrugation"

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Ishida, Makoto. "History of Mitigating Rolling Contact Fatigue and Corrugation of Railway Rails in Japan - Review". EPI International Journal of Engineering 1, n.º 2 (20 de noviembre de 2018): 13–24. http://dx.doi.org/10.25042/epi-ije.082018.02.

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Rail is the one of the most important materials to support and guide railway vehicles safely and smoothly. Since rail suffers from variousinteracting forces and environmental atmosphere, wear and fatigue pose large problems with wheel and rail. Hence, wear and fatigue ofwheel and rail have been studied so far to keep running safety and some level of riding comfort of vehicle taking into account trackmaintenance cost in the world. In this review, the history of theory and practice of rail maintenance in Japanese railways is describedfocusing on rolling contact fatigue (RCF) corrugation of rails caused by dynamic rolling friction at wheel/rail interface. In particular, “squat”mainly callled in UK or “rail surface shelling” called in Japan which is one of typical fatigue phenomenon for steel wheel-on-rail system andrail corrugations caused by dynamic lateral friction and vertical loading at sharp curves and/or long wavelength of rail corrugation causedby longitudinal roll-slip or stick-slip excited by the resonance of unsprung mass of bogie vertical vibration supported by track stiffness. Inaddition, the practice of countermeasure for RCF defect of squat, preventive grinding, and countermeasure for top of low rail corrugation,top of low rail lubrication “Friction Moderating System” are described. Also, the possibility of preventing long wavelength of rail corrugationformed in tangential track in undersea tunnel (salty water) enviornment is described.

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2

Ćirić, Ivan, Milan Banić, Miloš Simonović, Aleksandar Miltenović, Dušan Stamenković y Vlastimir Nikolić. "TOWARDS MACHINE VISION BASED RAILWAY ASSETS PREDICTIVE MAINTENANCE". Facta Universitatis, Series: Automatic Control and Robotics 19, n.º 2 (8 de diciembre de 2020): 125. http://dx.doi.org/10.22190/fuacr2002125c.

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The main goal of this paper is to present novel technologies that can contribute to safety, competitiveness, efficiency and operational reliability of Railway infrastructure through the development of innovative solutions for measuring and monitoring of railway assets based on machine vision. Measuring the transversal position of the wheels on the rail, as well as identification of the defects of the wheel and the rail (such as deformation of rail head edge, lateral wear, worn wheels, cracks in wheel and rail, rolling contact fatigue, corrugation and other irregularities) can increase reliability and lower maintenance costs. Currently, there is a need on the market for the innovative solution, namely the on-board high-speed stereo camera system augmented with a system that projects custom pattern (fringe scanner system) for measuring the transversal position of the wheels on the rail, robust to environmental conditions and waste along the track that can provide reliable measurements of transversal position of the wheels up to 200 km/h. New trends in Precise Industrial 3D Metrology are showing that stereo vision is an absolute must have in modern specialized optical precision measuring systems for the three-dimensional coordinate measurement.

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3

Axinte, Tiberiu. "Finite Elements Analysis of the Rail-Wheel Rolling Contact". Advanced Materials Research 1036 (octubre de 2014): 559–63. http://dx.doi.org/10.4028/www.scientific.net/amr.1036.559.

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The railway transportation system is nowadays one of the most important systems for land transport because its increased load carrying capacity, high speed, low costs, connectivity and ecologic features. As a result, the railways are subjected to additional loads which produce a higher level of strains and stresses. The rolling contact of a wheel on a rail is the basis of many rail-wheel related problems including the rail corrugation, wear, plastic deformation, rotating interaction fatigue, thermo-elastic-plastic behavior in contact, fracture, creep, and vehicle dynamics vibration. Therefore, this topic became the research subject for many researchers worldwide. Practical experience shows that the stress distribution is an important factor at the rail-wheel contact interfaces, that is, two materials in contact at rolling interfaces which are highly influenced by the geometry of the contacting surfaces, material constants, loads and boundary conditions. Three different procedures have conventionally been utilized to inspect rail-wheel contacts including Hertzs theory and Kalkers analytical method. The calculation of these stresses becomes much more complicated in three dimensional real size geometries. For this reason, many scientists have simplified the problem mainly by means of theoretical or numerical approaches based on the Hertzs theory, which can be considered the starting point of all subsequent researches. Both static and dynamic contact stresses have been carefully examined. Accurate theories, as well as computer software have been developed to evaluate all the parameters which influence the rail-wheel interaction. The analytical equations were employed to calculate the Hertzian stresses using the Octave software. For these elements, the simplifying hypothesis was to consider only the elastic properties of materials and, consequently, to neglect the elastic-plastic characteristics. Besides, many models generally neglected the friction coefficient between the rail and wheel, which is one of the most critical factors in determining the precise amount of stresses and distribution of contact pressure in rail-wheel contact area. On the other hand, some practical methods have also been introduced to solve traditional problems related to rail-wheel interaction. Other original contribution of this research is to create a precise finite element model of a 3D rail-wheel, axle and pads in order to evaluate stresses, strains, and contact forces in this complex interaction system. However, unlike many previous works, this study focuses on the real conditions of the problem including exact boundary and loading conditions, using real-size complete model of various components with precise shapes.

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4

Trummer, Gerald, Zing Siang Lee, Roger Lewis y Klaus Six. "Modelling of Frictional Conditions in the Wheel–Rail Interface Due to Application of Top-of-Rail Products". Lubricants 9, n.º 10 (8 de octubre de 2021): 100. http://dx.doi.org/10.3390/lubricants9100100.

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The coefficient of friction between a wheel tread and the top of the rail should be maintained at intermediate levels to limit frictional tangential contact forces. This can be achieved by applying top-of-rail products. Reducing the coefficient of friction to intermediate levels reduces energy consumption and fuel costs, as well as damage to the wheel and rail surfaces, such as, e.g., wear, rolling contact fatigue, and corrugation. This work describes a simulation model that predicts the evolution of the coefficient of friction as a function of the number of wheel passes and the distance from the application site for wayside application of top-of-rail products. The model considers the interplay of three mechanisms, namely the pick-up of product by the wheel at the application site, the repeated transfer of the product between the wheel and rail surfaces, and the product consumption. The model has been parameterized with data from small-scale twin disc rig experiments and full-scale wheel–rail rig experiments. Systematic investigations of the model behaviour for a railway operating scenario show that all three mechanisms may limit the achievable carry-on distance of the product. The developed simulation model assists in understanding the interplay of the mechanisms that govern the evolution of the coefficient of friction in the field. It may aid in finding optimal product application strategies with respect to application position, application amount, and application pattern depending on specific railway operating conditions.

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5

Khan, Saad Ahmed, Jan Lundberg y Christer Stenström. "Carry distance of top-of-rail friction modifiers". Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 232, n.º 10 (4 de mayo de 2018): 2418–30. http://dx.doi.org/10.1177/0954409718772981.

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Rail issues such as corrugation, rolling contact fatigue, noise and wear have been increasing with the increase in railway traffic. The application of top-of-rail friction modifiers (TOR-FMs) is claimed by their manufacturers in the railway industry to be a well-established technique for resolving the above-mentioned issues. There are various methods for applying friction modifiers at the wheel–rail interface, among which stationary wayside systems are recommended by TOR-FM manufacturers when a distance of a few kilometres is to be covered. TOR-FM manufacturers also claim that by using wayside equipment, the TOR-FM can be spread over a minimum distance of 3 km, over which it maintains a coefficient of friction of µ = 0.35 ± 0.05. To determine the carry distance of TOR-FMs, some researchers use tribometers to measure the coefficients of friction. However, moisture and deposits from the environment and trains can alter the top-of-rail friction and give a misleading indication of the presence of a friction modifier. Therefore, the coefficient of friction itself is not a clear indicator of the presence of TOR-FMs. In the present study, cotton swabs dipped in a mixture of alcohol and ester were used to collect surface deposits (a third body) from both the wheel and rail at various distances from the point of application. Subsequently, the third body collected on the cotton swab was analysed using an energy dispersive X-ray analysis. The results have shown that the maximum carry distance of TOR-FMs on the top of the rail is limited to 70 m when using a TOR-FM from one manufacturer and to 450 m when using a TOR-FM from another manufacturer. The carry distance on the contact band of the wheel is limited to 100 m and 340 m. The friction modifier on the edges of the contact band was detected over a distance of up to 3 km; however, this will not minimise the damage or friction at the wheel–rail interface.

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6

Seo, Jung Won, Hyun Kyu Jun, Seok Jin Kwon y Dong Hyeong Lee. "Rolling Contact Fatigue and Wear Behavior of Rail Steel under Dry Rolling-Sliding Contact Condition". Advanced Materials Research 891-892 (marzo de 2014): 1545–50. http://dx.doi.org/10.4028/www.scientific.net/amr.891-892.1545.

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Rolling contact fatigue and wear of rails are inevitable problems for railway system due to wheel and rail contact. Increased rail wear and increased fatigue damage such as shelling, head check, etc. require more frequent rail exchanges and more maintenance cost. The fatigue crack growth and wear forming on the contact surface are affected by a variety of parameters, such as vertical and traction load, friction coefficient on the surface. Also, wear and crack growth are not independent, but interact on each other. Surface cracks are removed by wear, which can be beneficial for rail, however too much wear shortens the life of rail. Therfore, it is important to understand contact fatigue and wear mechanism in rail steels according to a variety of parameters. In this study, we have investigated fatigue and wear characteriscs of rail steel using twin disc testing. Also the comparative wear behavior of KS60 and UIC 60 rail steel under dry rolling-sliding contact was performed.

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7

Johnson, K. L. "The Strength of Surfaces in Rolling Contact". Proceedings of the Institution of Mechanical Engineers, Part C: Mechanical Engineering Science 203, n.º 3 (mayo de 1989): 151–63. http://dx.doi.org/10.1243/pime_proc_1989_203_100_02.

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The common engineering applications of rolling contact are reviewed: the wheel, rolling bearings, traction drives, gears and cams. It is shown that increasing the rigidity of the materials and decreasing the conformity of the surfaces reduces the resistance to rolling, but only at the expense of higher contact stress. The principal modes of failure are described: plastic deformation, contact fatigue, wear, scuffing and corrugation. Recent research into plastic deformation and fatigue is discussed. It is concluded that, if wear and scuffing are controlled by adequate lubrication and surface finish, and clean steel is used, the load capacity and life are governed by the nucleation of micro shear cracks through the action of cyclic plastic deformation.

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8

Nielsen, J. C. O., A. Ekberg y R. Lundén. "Influence of Short-Pitch Wheel/Rail Corrugation on Rolling Contact Fatigue of Railway Wheels". Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 219, n.º 3 (1 de mayo de 2005): 177–87. http://dx.doi.org/10.1243/095440905x8871.

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A numerical procedure to integrate simulation of high-frequency dynamic train-track interaction and prediction of rolling contact fatigue (RCF) impact is presented. Features of the included models and possibilities of applications are outlined. The influence of short-pitch rail corrugation and wheel out-of-roundness (OOR) on RCF of a high-speed passenger train is investigated. It is shown how the corrugation and the OOR will have a profound effect in that levels of wheel and rail irregularities that have been measured in the field may be sufficient to generate subsurface-initiated RCF. In particular, the high-frequency content of the contact forces is of importance. Errors induced by neglecting such high-frequency components in measurements and/or simulations are investigated by comparing RCF indices based on contact forces that have been low-pass filtered with various cut-off frequencies. To avoid cracking due to RCF, a maximum roughness level in the wavelength interval up to 10 cm is sought. To limit the effects of corrugation, grinding practices have been altered leading to a significant decrease in RCF.

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9

Ekberg, Anders, Elena Kabo, Jens C. O. Nielsen y Roger Lundén. "Subsurface initiated rolling contact fatigue of railway wheels as generated by rail corrugation". International Journal of Solids and Structures 44, n.º 24 (diciembre de 2007): 7975–87. http://dx.doi.org/10.1016/j.ijsolstr.2007.05.022.

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10

Zhong, Wen, Jia Jie Hu, Cai Yun Wang, Peng Shen y Qi Yue Liu. "An Investigation to the Behavior of Fatigue Crack and Rail Selection for High-Speed". Advanced Materials Research 154-155 (octubre de 2010): 1131–36. http://dx.doi.org/10.4028/www.scientific.net/amr.154-155.1131.

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The rolling tests of railway rail were performed using a JD-1 wheel/rail simulation facility without any lubricant. The failure behaviour of rail rollers with different materials, was investigated in detail by examining wear volume and wear scar using optical microscopy (OM) and scanning electronic microscopy (SEM). The results indicate that rail material with a high hardness appears less plastic flow after rolling test. When the plastic flow is small, the wear resistance of material appears better. However, the crack propagation is more significant and fatigue damage is more severe. There is a mutual competitive relationship between wear and surface fatigue crack. A high wear rate can reduce rolling contact fatigue damage by removing constantly surface cracks. The analysis shows that U71Mn rail is more suitable for the high-speed railway.

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11

Zeng, Dong Fang y Lian Tao Lu. "Enhancement of Rolling Contact Wear and Fatigue Resistance of Wheel Steel by Laser Dispersed Treatment". Advanced Materials Research 891-892 (marzo de 2014): 1797–802. http://dx.doi.org/10.4028/www.scientific.net/amr.891-892.1797.

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Ferrite-pearlite steel is the most widely used material for railway wheel. However, such wheel steel can not meet the strict demands for rolling contact wear and fatigue resistance with the rising speed and weight of traffic. The aim of this paper is to improve the rolling contact wear and fatigue resistance of wheel steel by laser dispersed treatment. Such treatment creates isolated glazed regions on the surface layer of wheel steel, which are composed of fine martensite and retained autensite and have an avera0ge hardness of 762HV0.3. Compared with the conventional laser surface treatment technologies, such as laser hardening, laser melting, or laser cladding, which have been applied for improving rolling contact wear and fatigue resistance of wheel/rail, the multiple overlapping laser tracks that cause the premature failure are avoided by laser dispersed treatment. The wear rate and rolling contact fatigue life of treated and untreated wheel steel were evaluated and compared by Amsler twin-disc testing machines in dry and lubricated condition, respectively. The test results show that laser dispersed treatment improves the rolling contact wear and fatigue resistance of wheel steel. The stable wear rate of the laser treated wheel steel is about 0.3 times that of untreated wheel disc and the average rolling contact life of treated wheel steel is about double that of the untreated steel. Further investigations show that the glazed regions suppress the plastic deformation of wheel steel. This inhibits the treated wheel steel from delamination wear and delays the formation of fatigue crack initiation.

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12

Seo, Jung Won, Seok Jin Kwon, Dong Hyeog Lee y Ha Yong Choi. "Evaluation of Wear Behavior of Wheel Steel Using Twin-Disc Test". Advanced Materials Research 716 (julio de 2013): 434–37. http://dx.doi.org/10.4028/www.scientific.net/amr.716.434.

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The wheel/rail contact is chracterized by high contact forces and small contact areas. Although the standard of railway wheel has sustained, the damages of railway wheel have been occurred in service running. The railway wheel damage can be divided into three types; wear, contact fatigue failure and thermal crack due to braking. In curves, especially, large sliding on the contact patch occurs at the wheel tread and flange. Due to this sliding, wear increases in the wheel/rail contact under the dry condition. To reduce wear, more durable wheel steels are required. In order to develop new materials and predict wear, It is important to understand the wear mechanism in wheel steels. In this study, we have investigated the wear characteriscs of RSW1 railway wheel steel using twin disc wear testing. Also the comparative wear behavior of RSW1 and R7 wheel steel under rolling-sliding contact was performed.

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13

Wang, W. J., W. Zhong, J. Guo, Q. Y. Liu, M. H. Zhu y Z. R. Zhou. "Investigation on rolling contact fatigue and wear properties of railway rails". Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 223, n.º 7 (2 de junio de 2009): 1033–39. http://dx.doi.org/10.1243/13506501jet588.

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14

Hu, Jiajie, Wen Zhong y Qiyue Liu. "Study on the Performance of High-Speed Rail Damage of Four Different Materials". Advances in Materials Science and Engineering 2018 (2 de diciembre de 2018): 1–6. http://dx.doi.org/10.1155/2018/5016414.

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For four types of railway rails, corresponding rolling tests have been executed by using the JD-1 wheel/rail simulation device based on the Hertz simulation method, which can ensure the reciprocal contact condition between simulation rail and wheel under experimental conditions approximate to practical contact conditions. The results indicate that, for the rail material which has a higher hardness, the wear volume was less and the plastic deformation layer was thinner after the rolling test, but the crack propagation was more significant and the fatigue damage was severer, showing that its wear resistance was better. The analysis shows that the fatigue resistance of U71Mn rail was better, and considering fatigue is the main failure type for high-speed rail, so it is more suited to the high-speed railway.

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15

Jun, Hyun Kyu y Won Hee You. "Estimation of Crack Growth Life in Rail with a Squat Defect". Key Engineering Materials 417-418 (octubre de 2009): 313–16. http://dx.doi.org/10.4028/www.scientific.net/kem.417-418.313.

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Rolling contact fatigue initiated defects such as surface corrugation, head check, squat, are one of growing problems in high speed railway line. A squat is generally developed below the rail surface and grows parallel to surface until it turns down into rail. Estimation of critical crack size and crack growth rate is an essential to prevent rail from failure and develop cost effective railway maintenance strategy. In this study, we predict crack growth rate of a rail with a squat defect. For this purpose, a rail model with a squat defect is developed. Timoshenko’s beam theory is applied to calculate the global bending stress at the crack tip and Hertzian contact model is applied to calculate the local contact stresses at the surface of rail by simulating rolling over a railway wheel on a rail. Stress intensity factors are calculated from the total stress at the crack tip. Fatigue crack growth curve of 60kg rail steel is applied to calculated crack growth rate. Software to predict crack growth life through whole life cycle is developed. We expect that we can make a more cost effective rail maintenance strategy by considering the crack growth analysis for a defective rail.

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16

He, Chenggang, Jihua Liu, Wenjian Wang y Qiyue Liu. "The Tribo-Fatigue Damage Transition and Mapping for Wheel Material under Rolling-Sliding Contact Condition". Materials 12, n.º 24 (10 de diciembre de 2019): 4138. http://dx.doi.org/10.3390/ma12244138.

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The purpose of this work is to construct a tribo-fatigue damage map of high-speed railway wheel material under different tangential forces and contact pressure conditions through JD-1 testing equipment. The results indicate that the wear rate of the wheel material varies with tangential force and contact pressure. The wear mapping of the wheel material is constructed and divided into three regions: slight wear, severe wear, and destructive wear, based on the wear rate under each test condition. With an increase in tangential force and contact pressure, the maximum crack length and average crack length of the wheel material increases. According to the surface damage morphologies and corresponding statistical results of average crack length of wheel material under each experiment condition, a tribo-fatigue damage map is constructed and divided into three regions: slight fatigue damage region, fatigue damage region, and severe fatigue damage region. Fatigue cracks initiate on the wheel specimen surface. Some cracks may propagate into material and fracture under cyclic rolling contact; some cracks may grow into inner material with a certain depth, and then turn toward the surface to form material flaking; some cracks may always propagate parallel to the wheel roller surface.

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17

Mazzù, Angelo. "Experimental and Numerical Characterization of a Rail Steel Behavior under Cyclic Contact Stresses". Key Engineering Materials 348-349 (septiembre de 2007): 569–72. http://dx.doi.org/10.4028/www.scientific.net/kem.348-349.569.

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Wear and rolling contact fatigue interaction in rolling/sliding contact is an important topic in the research on structural integrity of rails and railway wheels. Wear is in competition with rolling contact fatigue, as it removes surface material layers, reducing cracks length and hindering their propagation. Cracks nucleate by accumulation of cyclic unidirectional plastic strain (ratcheting). In this paper a model for ratcheting assessment is discussed and applied to the UIC 900A steel, after a calibration based on experimental results. The experimental tests allow also a characterization of the crack formation condition for this material. By this model, a computer program is developed in order to simulate in a very short time the effect of a large number of load cycles, providing a tool for predicting crack formation and propagation rates.

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18

Megna, Gianluca y Andrea Bracciali. "Gearless Track-Friendly Metro with Guided Independently Rotating Wheels". Urban Rail Transit 7, n.º 4 (18 de noviembre de 2021): 285–300. http://dx.doi.org/10.1007/s40864-021-00159-2.

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AbstractTrack–vehicle severe interaction on track with small curve radius results in rail wear and corrugation, and wheel polygonization, which drain considerable resources for rail grinding and wheels re-profiling in metro lines. To reduce the damage caused by track-vehicle severe interaction, the paper analyzes the reasons leading to rail wear and then proposes an architecture of a metro vehicle with independently rotating wheels driven directly by permanent magnet synchronous motors. The architecture is axle guidance, offered by passive linkages, which ensures that all axles are oriented radially, while control strategy was kept as simple as possible, identifying only two basic traction conditions. The concept is first discussed and then validated through a comprehensive set of running dynamics simulation performed with a multibody software to evaluate rail wear and rolling contact fatigue in traction/braking, coasting with different cant deficiency/excess conditions. The multibody dynamics simulation shows that the proposed architecture is virtually capable of avoiding both wear and rolling contact fatigue damages, and achieves the highest possible track friendliness. The concept of the proposed architecture is a track-fiendly metro architecture and could be a good reference for reducing rail-track interaction damages and maintainace cost.

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19

Bąkowski, Henryk, Antoni John, Łukasz Łomozik y Zbigniew Stanik. "THE IMPACT OF WATER UPON THE WEAR OF RAILWAY RAILS IN SELECTED SERVICE CONDITIONS". Tribologia 284, n.º 2 (30 de abril de 2019): 15–25. http://dx.doi.org/10.5604/01.3001.0013.4145.

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The article presents, in a complex way, the impact of most essential operational factors upon tribological properties such as the wear and the friction coefficient being the main causes of fatigue contact wear in the rolling-sliding contact both in the presence and absence of water. Operational curves have been developed to predict the character and intensity of the wear in various operational conditions. This seems crucial for the improvement of the safety of rail vehicles.

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20

Faccoli, Michela, Candida Petrogalli, Matteo Lancini, Andrea Ghidini y Angelo Mazzù. "Rolling Contact Fatigue and Wear Behavior of High-Performance Railway Wheel Steels Under Various Rolling-Sliding Contact Conditions". Journal of Materials Engineering and Performance 26, n.º 7 (19 de junio de 2017): 3271–84. http://dx.doi.org/10.1007/s11665-017-2786-4.

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21

Wu, Qiang, Tao Qin, Mingxue Shen, Kangjie Rong, Guangyao Xiong y Jinfang Peng. "Effect of Gas Nitriding on Interface Adhesion and Surface Damage of CL60 Railway Wheels under Rolling Contact Conditions". Metals 10, n.º 7 (8 de julio de 2020): 911. http://dx.doi.org/10.3390/met10070911.

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The influence of surface gas nitriding on wheel/rail rolling contact fatigue and wear behavior of CL60 wheel was studied on a new rolling contact fatigue/wear tester (JD-DRCF/M). The failure mechanisms of the wheel/rail surface after the gas nitriding and without gas nitriding on the wheel surface were compared and analyzed. The results show that the wheel with gas nitriding could form a dense and hard white bright layer which was approximately 25 μm thick and a diffusion layer which was approximately 70 μm thick on the wheel surface. Thus, the gas nitriding on the railway wheel not only significantly improved the wear resistance on the surface of the wheel, but also effectively reduced the wear of the rail; the results show that the material loss reduced by 58.05% and 10.77%, respectively. After the wheel surface was subjected to gas nitriding, the adhesive coefficient between the wheel/rail was reduced by 11.7% in dry conditions, and was reduced by 18.4% in water media, but even so, the wheel with gas nitriding still could keep a satisfactory adhesive coefficient between the wheel/rail systems, which can prevent the occurrence of phenomena such as wheel-slip. In short, the gas nitriding on the wheel surface can effectively reduce the wear, and improve the rolling contact fatigue resistance of the wheel/rail system. This study enlarges the application field of gas nitriding and provides a new method for the surface protection of railway wheels in heavy-duty transportation.

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Makoto ISHIDA. "Rolling contact fatigue (RCF) defects of rails in Japanese railways and its mitigation strategies". Electronic Journal of Structural Engineering 13, n.º 1 (1 de enero de 2013): 67–74. http://dx.doi.org/10.56748/ejse.131621.

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Rail is the one of the most important materials to support and guide railway vehicles safely and smoothly. Since rail sufferes from various interacting forces and environmental atmosphere, wear and fatigue pose large problems with wheel and rail. Hence, wear and fatigue of wheel and rail have been studied so far to keep running safety and some level of riding comfort of vehicle taking into account track maintenance cost. In this review, rolling contact fatigue (RCF) of rail which is one of typical fatigue phenomenon for steel wheelon- rail system is focused on and the history of RCF defects and the maintenance experience of their mitigation measures in Japanese railways are described. The concept of mitigation strategy is balance between wear and RCF. Controlling wear amount is a key word to mitigate RCF defects based on selecting rail material suitable for vehicle/track interaction together with grinding and lubrication. Furthermore, the purpose of Japanese bainitic steel rail is to obtain the suitable amount of wear to prevent the initiation of RCF crack.

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23

Shevtsov, I. Y., V. L. Markine y C. Esveld. "Design of railway wheel profile taking into account rolling contact fatigue and wear". Wear 265, n.º 9-10 (octubre de 2008): 1273–82. http://dx.doi.org/10.1016/j.wear.2008.03.018.

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Cvetkovski, K., J. Ahlström, M. Norell y C. Persson. "Analysis of wear debris in rolling contact fatigue cracks of pearlitic railway wheels". Wear 314, n.º 1-2 (junio de 2014): 51–56. http://dx.doi.org/10.1016/j.wear.2013.11.049.

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25

Zhong, W., J. W. Ren, W. J. Wang, Q. Y. Liu y Z. R. Zhou. "Investigation between rolling contact fatigue and wear of high speed and heavy haul railway". Tribology - Materials, Surfaces & Interfaces 4, n.º 4 (diciembre de 2010): 197–202. http://dx.doi.org/10.1179/1751584x10y.0000000003.

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26

Lancini, Matteo, Ileana Bodini, David Vetturi, Simone Pasinetti, Angelo Mazzù, Luigi Solazzi, Candida Petrogalli y Michela Faccoli. "Using vibrations to detect high wear rates in rolling contact fatigue tests". ACTA IMEKO 4, n.º 4 (23 de diciembre de 2015): 66. http://dx.doi.org/10.21014/acta_imeko.v4i4.237.

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Rolling contact fatigue (RCF) plays a critical role in railway components, and the characterization of materials used, in terms of RCF life, is still an open task, made complex by the interactions of different phenomena. The contact surface has a direct impact on the pressure exerted and can change during the test, due to wear. The procedure proposed consists in using vibrations of a test bench during RCF?life tests to identify when wear increases and causes a quick flattening of the specimen’s surface, and when this process is complete. The procedure is applied to two case studies regarding wheel and rail steels. In the tests, a wheel steel specimen rotates against a rail steel specimen, while pressed against each other by a constant force. At regular intervals weight loss and surface analysis are performed, while vibrations and torque are monitored continuously. Destructive tests are carried out at the end of each test. Results from non?destructive measurements were used to provide input data to a numerical simulation, used to determine the cyclic plasticity properties of the material. The methodology proposed shows the potential application of vibration measurements for detecting wear rates thus allowing supporting or partially supplanting destructive testing.

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27

Hou, Maorui, Bingzhi Chen y Di Cheng. "Study on the Evolution of Wheel Wear and Its Impact on Vehicle Dynamics of High-Speed Trains". Coatings 12, n.º 9 (14 de septiembre de 2022): 1333. http://dx.doi.org/10.3390/coatings12091333.

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Wheel wear is one of the most critical factors affecting the vehicle performances and maintenance costs of railway vehicles. However, previous research has to ignore the initial wheel-rail profiles for the evolution of wheel wear. Therefore, this work investigates the relationship between the evolution of wheel wear corresponding to different initial wheel-rail profiles and vehicle dynamics, wheel-rail deterioration. Firstly, the evolution of wheel wear during a long service period is measured from two high-speed railway trains running on two different lines. Contact geometry, e.g., equivalent conicity and contact pair distribution, are extracted. After that, the influence of wheel wear on the vehicle dynamic performance is studied using a multi-body dynamic software. The calculated contact parameters, e.g., pressure, shear traction, and creepage, are used to analyze the distribution of rolling contact fatigue. Based on the experimental and simulation results, the initial wheel and rail profiles significantly affects the wheel wear pattern, the thin rim wheel has uniform wear, and other wheels occurs hollow wear. The hollow wear can lead to gradual deterioration of vehicle dynamics, which conversely aggravates the wheel reprofiling.

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28

Sakalo, V. I. y A. V. Sakalo. "Criteria for predicting the initiation of rolling contact fatigue damage in the railway wheels and rails". Vestnik of the Railway Research Institute 78, n.º 3 (28 de julio de 2019): 141–48. http://dx.doi.org/10.21780/2223-9731-2019-78-3-141-148.

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The development of the methods for modeling the processes of accumulation of the rolling contact fatigue damage and wear of the wheels of the railway rolling stock and the rails is particularly relevant due to the increase in the number of damage in the recent times. The work is underway to improve the chemical composition and the technology of production of the wheel and rail steels in order to improve their mechanical properties and ability to resist the action of the cyclic loads. The methods of modeling allow predict the possibility of initiation of the fatigue cracks during operation with the sufficient accuracy in the short time. The selection of the contact fatigue criterion and the mathematical apparatus for calculating the stresses at points in the area adjacent to the contact patch to obtain the numerical values of the criterion components is the most important task in the development of modeling methods. The article focuses on the approaches based on the Dang Van criterion and the shakedown diagram for a material undergoing to the action of cyclic loads, which are widely used to assess the rolling contact fatigue of the wheels and rails. The assumptions that are used in the development of the algorithms concerning the models of the contacting bodies, the shape of the contact patch, the distribution of the contact pressures and the tangential forces are considered. The approach using the criterion — the amplitude value of the maximal shear stress is also considered. The example of modeling the process of accumulation of the rolling contact fatigue damage in the wheel of the freight car is given. The results of modeling are presented in the form of the isolines of the criterion values and the accumulated damage in the area adjacent to the contact patch. This work was supported by the Russian Foundation for Basic Research under Grant [17-01-00815A].

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29

Karttunen, Kalle, Elena Kabo y Anders Ekberg. "A numerical study of the influence of lateral geometry irregularities on mechanical deterioration of freight tracks". Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 226, n.º 6 (23 de abril de 2012): 575–86. http://dx.doi.org/10.1177/0954409712445115.

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Optimisation of railway track maintenance requires knowledge of how a deteriorated track geometry will affect subsequent loading and damage of the track. This is the scope of the current study where, in particular, the influence on track shift forces and rolling contact fatigue is investigated through numerical simulations. To this end, track geometries are obtained from field measurements. Lateral irregularities are extracted and scaled to represent different levels of geometry deterioration. Multibody simulations of dynamic train–track interaction featuring two freight wagon types are performed under different operational conditions. Track shift forces and rolling contact fatigue damage are further evaluated from simulation results. It is found that track shift forces tend to follow a normal distribution for moderate levels of lateral track geometry irregularities, and that an approximate linear relationship between standard deviations of lateral irregularities and track shift forces can be established. The relation between lateral track irregularity magnitude and rolling contact fatigue is more complex. Increasing levels of lateral irregularities will decrease the fraction of curve length affected by rolling contact fatigue for sharp curves, whereas for shallow curves it increases. As detailed in the article, this is caused by the lateral movement of the contact point as imposed by the track irregularities. Furthermore, the influence of wheel/rail friction and wear is investigated.

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30

Leso, TP, CW Siyayisa, RJ Mostert y J. Moema. "Study of wear performance of wheel and rail steels under dry sliding conditions". Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie 40, n.º 1 (24 de enero de 2022): 44–50. http://dx.doi.org/10.36303/satnt.2021cosaami.09.

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The demand for efficient railway services has significantly increased in the past years due to an increased demand for the high-speed transportation of goods with high loads. The increase in loads and velocities has resulted in increased problems associated with rolling contact fatigue (RCF), rolling and sliding wear on the wheel and rail materials causing a reduction of service life of wheel/rail systems. Rail operating companies spend significant funds in maintenance and replacing damaged rails and wheels caused by wear. In addition, unscheduled maintenance due to wear and RCF often lead to poor availability of railway networks. For this study, dry sliding wear was investigated on wheel and rail steels using RTEC Multi-Function Tribometer. The results demonstrated that the rig was successful in simulating sliding wear, and that the fractions of the wear components could be varied, and it also provided instrumentation. Information on coefficient of friction against sliding distance and applied force were obtained which were used to compare sliding wear performance of both wheel and rail steels. The wheel was found to perform better than the rail under the same conditions due to its high initial hardness values and smaller interlamellar spacing.

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31

Magel, Eric y Joe Kalousek. "Designing and assessing wheel/rail profiles for improved rolling contact fatigue and wear performance". Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 231, n.º 7 (1 de junio de 2017): 805–18. http://dx.doi.org/10.1177/0954409717708079.

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A quick survey of wheel and rail profiles used around the world reveals a huge range of options. Wheels come in cylindrical, conical, and concave variations, while rails range in shape from a very flat 14 in. (350 mm) head radius to a tightly crowned 6 in. (150 mm) head radius. The rationale for implementing one or the other is often institutional inertia—a strong tendency to continue doing what has been done in the past. But the impacts of wheel and rail profiles on the performance of the vehicle/track interaction are large and the decision should not be made lightly. Unfortunately, there are few well-matched “off-the-shelf” solutions from the existing commercially available profiles, such that new rails and wheels often suffer early failures or infant mortality. Through examples and case studies, this paper discusses the significant role that wheel and rail profiles play with respect to performance and safety and makes the case for wheel and rail profiles specifically suited to the needs of each railway. Various techniques for assessing the performance of systems of wheels and rails are reviewed and discussed.

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32

Zeng, Dongfang, Liantao Lu, Zhengyang Li, Jiwang Zhang, Xuesong Jin y Minhao Zhu. "Influence of laser dispersed treatment on rolling contact wear and fatigue behavior of railway wheel steel". Materials & Design (1980-2015) 54 (febrero de 2014): 137–43. http://dx.doi.org/10.1016/j.matdes.2013.08.041.

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33

Faccoli, Michela, Candida Petrogalli, Matteo Lancini, Andrea Ghidini y Angelo Mazzù. "Effect of desert sand on wear and rolling contact fatigue behaviour of various railway wheel steels". Wear 396-397 (febrero de 2018): 146–61. http://dx.doi.org/10.1016/j.wear.2017.05.012.

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34

Lee, Chan Woo y Seok Jin Kwon. "Evaluation of Surface Defects of Wheel and Rail for Korean High-Speed Railway". Materials Science Forum 654-656 (junio de 2010): 2499–502. http://dx.doi.org/10.4028/www.scientific.net/msf.654-656.2499.

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Wheels of the railway vehicle play the important role for driving train through wheel-rail interaction. Especially wheel profile is one of the most important design factors to rule the running stability and safety of train. Accordingly, the control of rolling contact fatigue-related defects is an ongoing concern for both safety and cost reasons. This process is referred to as ratcheting. Wear of wheel and rail surfaces occur due to a mixture of adhesive, abrasive and corrosive processes. In wheel/rail systems with little wear, such failure is manifested by the appearance of closely spaced micro-cracks. In the present paper, a evaluation of surface defects of wheel and rail for Korean high-speed railway. The main research application is the wheel-rail maintenance of Korea high-speed train.

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35

Jin, Xuesong. "Research Progress of High-Speed Wheel–Rail Relationship". Lubricants 10, n.º 10 (30 de septiembre de 2022): 248. http://dx.doi.org/10.3390/lubricants10100248.

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The research on wheel–rail relationship includes the basic theoretical models and corresponding numerical methods of wheel–rail in rolling contact, geometric parameter matching and material matching of them, friction and wear, wheel–rail rolling contact fatigue, wheel–rail adhesion and noise. They are also key theoretical and technical problems of the high-speed train/track coupling system. The basic theoretical models of wheel–rail in rolling contact and the corresponding numerical methods are the basis and one of the basic means for solving other wheel–rail relationship problems. The other is the experimental means. Moreover, the modeling and analysis of coupling behavior of the train and track can only be realized by means of the wheel–rail rolling contact mechanics model and its corresponding numerical method. This paper mainly discusses some research work and achievements on high-speed wheel–rail relationship problems since China opened a high-speed railway system on a large scale. The discussions in this paper include the classic wheel–rail rolling contact theoretical models (analytical forms) and the modern wheel–rail rolling contact theories (numerical methods), their advantages and disadvantages, their application and future development direction of them. The reviewed research progress on the other wheel–rail relationships mainly expounds the thorny problems of the wheel–rail relationship encountered in the operation of China’s high-speed railway, how to adopt new theoretical analysis methods, test means and take effective measures to solve these problems. It also includes research results of similar important reference values performed by international peer experts in related fields. Challenging and unsolved problems in high-speed wheel–rail relationship research are also reviewed in the full text.

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36

TOTH, Constantin Silviu y Silviu Dănuți MĂCUȚĂ. "REVIEW ON THE FATIGUE BEHAVIOR OF THE WHEELS OF RAILWAY VEHICLES IN CONTACT WITH RAIL". Mechanical Testing and Diagnosis 9, n.º 4 (15 de enero de 2020): 5–11. http://dx.doi.org/10.35219/mtd.2019.4.01.

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Rail transport is essential to the EU's strategy for a more sustainable transport sector, economic and social cohesion and connecting Europeans at and between each Member State. EU trend is to support the railway sector as a clean, main mode of transport at European level. The European rail system carries around 1.6 billion tones of freight and 9 billion passengers each year. The railway sector has a substantial contribution to the EU economy, directly employing over 1 million people. With the technological evolution of railway vehicles, it is important to focus on safety issues. Wheels are one of the most critical components of railway vehicles, as their failure can lead to derailment. Therefore, an exact project on the control of the problem of wheel fatigue and knowledge of the effective parameters on their life, can improve the life of the whole structure. Due to the fact that the nature of the loads applied to the wheels is repeated, fatigue is very common mechanism of damage that can occur in several ways, such as: nucleation and growth of fatigue cracks, spalling, shelling, and so forth. The main sources of these phenomena are the rolling contact loads, the thermal loads between the wheel-rail and the wheel-brake block, created in the braking phase, the presence of structural defects in the wheel material; it follows that they cannot be omitted in a rigorous design. Increasing of speed aggravates these factors and exacerbates the problem of thermal fatigue of the wheels. In this paper we present a series of studies that focused on the wear of the wheels of railway vehicles in contact with the steering track (rail) to fatigue.

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37

Harzallah, R., A. Mouftiez, S. Hariri, E. Felder y J. P. Maujean. "Impact and Sliding Wear Resistance of Hadfield and Rail Steel". Applied Mechanics and Materials 146 (diciembre de 2011): 112–23. http://dx.doi.org/10.4028/www.scientific.net/amm.146.112.

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Railway networks are subjected to more and more severe loading conditions requiring the use of steels with a high resistance to wear and good fatigue behaviour. The surveys carried out on out of use equipment, such as rails or switches, show that these equipments fail by wear after quite a long period of use, but they can fail by fatigue in a substantially shorter time. In service, crossings are submitted to rolling, impact and sliding stresses. The impact-sliding is the result of the wheel transition from rail wing to crossing nose. Very high contact forces act on the crossing nose while such wheels are passing over it. These large contact forces between wheel and crossing can cause severe damage at crossing nose and wing rail. The influence of contact parameters on the damage of the crossing alloy (Hadfield steel GX120Mn13) in comparison with rail steel (R260) was investigated by impact and impact-sliding tests. The results are described and discussed using weight loss and microhardness measurements, optical and scanning electron microscopy observations of the contact surface. Examination of the results shows large plastic deformation in surface and subsurface of samples. In comparison with impact tests, sliding produces a change in size and shape of the contact area, a higher weight loss and lower hardening. A better impact–sliding wear resistance of Hadfield steel has been confirmed.

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38

Morozov, E. M. y A. P. Soldatenkov. "The statistical characteristics of the rail steel wear in conditions of fretting-fatigue". Industrial laboratory. Diagnostics of materials 84, n.º 11 (3 de diciembre de 2018): 70–73. http://dx.doi.org/10.26896/1028-6861-2018-84-11-70-73.

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A method of processing the results of tests for fretting fatigue drawn on the literature, is presented to determine a quantitative measure to be used in assessing the surface wear resistance in conditions of contact cyclic loading. Operation practice and experiments indicate to multiple micro-cracks of different sizes present on the contact surface. An assumption is made regarding the accidental character of the crack birth thus making possible the use of the mathematical statistics to obtain the characteristics treated as the mechanical properties of the crack resistance, which assess the resistance of contact fatigue material. The samples of three steel grades used for railway rail production are studied. The wear resistance is assessed through robust statistical characteristics under the assumption that occurrence of the surface defects is a random process. The loading is carried out in conditions of rolling friction with the balls spinning in the mandrel, thus forming an annular wear pad. As the load on the test rig is considered an analogue of the force action of the wheel on the rail, the wear resistance can become a quantitative measure of the quality of the rail steel. Measurements on each sample were made for three runs. The curves of the density of the defect area distribution on the wear surface of the samples are presented. Quantitative characteristics are proposed to estimate the fretting fatigue resistance of the metal, namely, the average crack area, standard deviation and the variation coefficient. Those characteristics are the parameters of statistical processing of experimental observations of the number and size of the surface cracks that occur under cyclic loading of the metal surface. The degree of significance of the observed damages is discussed to be used as an indicator when comparing different steels in the wear resistance. The results of the experiment made it possible to arrange three studied steels in a series of their fretting corrosion resistance: the Japanese steel has the greatest resistance to contact wear, then Russian steel and then Polish steel that exhibits the least resistance to contact wear.

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39

Wang, Pu, Liang Gao y Bo Wen Hou. "Influence of Rail Cant on Wheel-Rail Contact Relationship and Dynamic Performance in Curves for Heavy Haul Railway". Applied Mechanics and Materials 365-366 (agosto de 2013): 381–87. http://dx.doi.org/10.4028/www.scientific.net/amm.365-366.381.

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Rail cant is one of the most important track geometry parameters, which can change the wheel-rail contact relationship and then influence the dynamic interaction. Static contact geometry parameters for 75kg/m rail in contact with LM wheel tread under different rail cants are analyzed on the basis of the wheel-rail spatial contact geometry algorithm. A train (multi-vehicle)-track coupling dynamic model is established with the help of the software Universal Mechanism (UM), and dynamic performances of train-track system in curves are compared under different rail cants. The results indicate that: (1) flange contact is less likely to occur under 1/20 rail cant, which will reduce uneven wear of wheel/rail tread. (2) In the single-point contact range, when the rail cant increases from 1/40 to 1/20, the corresponding rolling radius difference, contact angle parameter, equivalent conicity and equivalent contact angle parameter all increase, which means the self-centring capacity of wheelset is enhanced and the wheel-rail relationship is improved. (3) When the train passes curves, the increase of rail cant from 1/40 to 1/20 can reduce the wheel-rail dynamic interaction and wear. Besides, the wheel-rail contact area may become bigger, which is conductive to reducing contact stress and contact fatigue failures. The results can provide reference for the design of rail cant of heavy haul railway.

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40

Rezende, A. B., S. T. Fonseca, R. S. Miranda, F. M. Fernandes, F. A. F. Grijalba, P. F. S. Farina y P. R. Mei. "Effect of niobium and molybdenum addition on the wear resistance and the rolling contact fatigue of railway wheels". Wear 466-467 (febrero de 2021): 203571. http://dx.doi.org/10.1016/j.wear.2020.203571.

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41

Lu, Xin, Tony W. Makowsky, Donald T. Eadie, Kevin Oldknow, Jilian Xue, Jinzhong Jia, Guibao Li, Xianhong Meng, Yude Xu y Yu Zhou. "Friction management on a Chinese heavy haul coal line". Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 226, n.º 6 (18 de mayo de 2012): 630–40. http://dx.doi.org/10.1177/0954409712447170.

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Shuohuang Railway (SHR) is one of the major coal carriers in China, with a total network length of 590 km running from Shenchi to Huanghua. Significant increases in annual operating tonnage have generated accelerated rail wear and rolling contact fatigue (RCF) growth problems for many sharper/lower radius curves. In order to address these rail problems, SHR is interested in the state-of-the-art total friction management (TFM) technology currently deployed by some North American heavy haul freight railroads and is evaluating the impact of TFM via a field trial at SHR’s Yuanping subdivision. This paper presents an evaluation of the effect of TFM, which includes both wayside gauge face lubrication and wayside application of a thin film top of rail friction modifier on control of lateral forces, rail wear and RCF.

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42

Provezza, Luca, Ileana Bodini, Candida Petrogalli, Matteo Lancini, Luigi Solazzi y Michela Faccoli. "Monitoring the Damage Evolution in Rolling Contact Fatigue Tests Using Machine Learning and Vibrations". Metals 11, n.º 2 (6 de febrero de 2021): 283. http://dx.doi.org/10.3390/met11020283.

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This study shows the application of a system to monitor the state of damage of railway wheel steel specimens during rolling contact fatigue tests. This system can make continuous measurements with an evaluation of damage without stopping the tests and without destructive measurements. Four tests were carried out to train the system by recording torque and vibration data. Both statistical and spectral features were extracted from the sensors signals. A Principal Component Analysis (PCA) was performed to reduce the volume of the initial dataset; then, the data were classified with the k-means algorithm. The results were then converted into probabilities curves. Metallurgical investigations (optical micrographs, wear curves) and hardness tests were carried out to assess the trends of machine learning analysis. The training tests were used to train the proposed algorithm. Three validation tests were performed by using the real-time results of the k-means algorithm as a stop condition. Metallurgical analysis was performed also in this case. The validation tests follow the results of the training test and metallurgical analysis confirms the damage found with the machine learning analysis: when the membership probability of the cluster corresponding to the damage state reaches a value higher than 0.5, the metallurgical analysis clearly shows the cracks on the surface of the specimen due to the rolling contact fatigue (RCF) damage mechanism. These preliminary results are positive, even if reproduced on a limited set of specimens. This approach could be integrated in rolling contact fatigue tests to provide additional information on damage progression.

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43

Ye, Yun-guang, Da-chuan Shi, Sara Poveda-Reyes y Markus Hecht. "Quantification of the influence of rolling stock failures on track deterioration". Journal of Zhejiang University-SCIENCE A 21, n.º 10 (octubre de 2020): 783–98. http://dx.doi.org/10.1631/jzus.a2000033.

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AbstractThis study focuses on the quantification of the influence of rolling stock failures (RSFs) on railway infrastructure. Taking the wheel flat, a common RSF, as an example, we introduce four quantification indexes to evaluate the influence on the following four deterioration mechanisms: track settlement (TS), track component fatigue (TCF), abrasive wear (AW), and rolling contact fatigue (RCF). Our results indicate that TS, TCF, and AW increase sharply with the increase of the wheel flat length and the vehicle speed, and this increasing trend becomes more acute with the increase of the wheel flat length and the vehicle speed. At low speeds, RCF increases gradually as the wheel flat length increases; at high speeds, it increases sharply at first and then decreases gradually. The influence of the wheel flat on TCF and AW is the most obvious, followed by TS and RCF. These findings can help infrastructure managers (IMs) to better understand infrastructure conditions related to RSFs and can aid them in managing problems with vehicle abnormality in track access charging.

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44

Sakalo, V., A. Sakalo, A. Rodikov y S. Tomashevskiy. "Computer modeling of processes of wear and accumulation of rolling contact fatigue damage in railway wheels using combined criterion". Wear 432-433 (agosto de 2019): 102900. http://dx.doi.org/10.1016/j.wear.2019.05.015.

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45

Khan, Saad Ahmed, Ingemar Persson, Jan Lundberg y Christer Stenström. "Prediction of the effects of friction control on top-of-rail cracks". Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 232, n.º 2 (26 de octubre de 2016): 484–94. http://dx.doi.org/10.1177/0954409716674984.

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Rolling contact fatigue is a major problem connected with railway tracks, especially in curves, since it leads to higher maintenance costs. By optimising the top-of-rail friction, the wear and cracks on the top of the rail can eventually be reduced without causing very long braking distances. There are several research articles available on crack prediction, but most of the research is focused either on rail without a friction modifier or on wheels with and without friction control. In the present study, in order to predict the formation of surface-initiated rolling contact fatigue, a range of friction coefficients with different Kalker’s reduction factors has been assumed. Kalker’s reduction factor takes care of the basic tendency of creepage as a function of the traction forces at lower creepage. The assumed range covers possible friction values from those for non-lubricated rail to those for rail with a minimum measured friction control on the top of the rail using a friction modifier. A fatigue index model based on the shakedown theory was used to predict the generation of surface-initiated rolling contact fatigue. Simulations were performed using multi-body simulation, for which inputs were taken from the Iron Ore line in the north of Sweden. The effect of friction control was studied for different curve radii, ranging from 200 m to 3000 m, and for different axle loads from 30 to 40 tonnes at a constant train speed of 60 km/h. One example of a result is that a maximum friction coefficient (µ) of 0.2 with a Kalker’s reduction factor of 15% is needed in the case of trains with a heavy axle load to avoid crack formation.

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46

Ye, Yunguang, Yu Sun, Shiping Dongfang, Dachuan Shi y Markus Hecht. "Optimizing wheel profiles and suspensions for railway vehicles operating on specific lines to reduce wheel wear: a case study". Multibody System Dynamics 51, n.º 1 (16 de enero de 2020): 91–122. http://dx.doi.org/10.1007/s11044-020-09722-4.

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AbstractThe selection of a wheel profile is a topic of great interest as it can affect running performances and wheel wear, which needs to be determined based on the actual operational line. Most existing studies, however, aim to improve running performances or reduce contact forces/wear/rolling contact fatigue (RCF) on curves with ideal radii, with little attention to the track layout parameters, including curves, superelevation, gauge, and cant, etc. In contrast, with the expansion of urbanization, as well as some unique geographic or economic reasons, more and more railway vehicles shuttle on fixed lines. For these vehicles, the traditional wheel profile designing method may not be the optimal choice. In this sense, this paper presents a novel wheel profile designing method, which combines FaSrtip, wheel material loss function developed by University of Sheffield (USFD function), and Kriging surrogate model (KSM), to reduce wheel wear for these vehicles that primarily operate on fixed lines, for which an Sgnss wagon running on the German Blankenburg–Rübeland railway line is introduced as a case. Besides, regarding the influence of vehicle suspension characteristics on wheel wear, most of the studies have studied the lateral stiffness, longitudinal stiffness, and yaw damper characteristics of suspension systems, since these parameters have an obvious influence on wheel wear. However, there is currently little research on the relationship between the vertical suspension characteristics and wheel wear. Therefore, it is also investigated in this paper, and a suggestion for the arrangement of the vertical primary spring stiffness of the Y25 bogie is given.

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47

Zhong, W., J. J. Hu, P. Shen, C. Y. Wang y Q. Y. Lius. "Experimental investigation between rolling contact fatigue and wear of high-speed and heavy-haul railway and selection of rail material". Wear 271, n.º 9-10 (julio de 2011): 2485–93. http://dx.doi.org/10.1016/j.wear.2010.12.053.

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48

Fasihi, Panahsadat, Olivia Kendall, Ralph Abrahams, Peter Mutton, Cong Qiu, Thomas Schläfer y Wenyi Yan. "Tribological Properties of Laser Cladded Alloys for Repair of Rail Components". Materials 15, n.º 21 (25 de octubre de 2022): 7466. http://dx.doi.org/10.3390/ma15217466.

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Tram or light rail systems are heavily relied upon for passenger transit; however, low-carbon steel grades commonly used in special trackwork, such as in switches, are prone to wear, rolling contact fatigue (RCF), and deformation under cyclic wheel–rail contact. To address this, laser cladding can be used to apply a metal coating to protect the underlying substrate and rebuild the worn rail profiles. Laser cladding may also be applied to remove cracking by rebuilding the rail head. The tribological characteristics of light rail components after laser cladding with Stellite 6 and a newly developed martensitic stainless steel were investigated, using roller-on-disc wear testing. Analysis of the microstructure, mechanical properties, and wear performance was undertaken to develop a comprehensive understanding of the influence of the laser cladding type on the wear and surface fatigue performance. Both cladding alloys significantly improved the tribological performance. These findings were compared to those for a laser cladded hypereutectoid rail type (reported in our previous study). It was found that laser cladding with a suitable alloy was an effective technique for improving the tribological properties, increasing the wear resistance, and increasing the retardation of cracking on both substrates. These findings suggest laser cladding may be used to repair light rail components, and this technique can be optimized to suit different rail grades. This makes laser cladding a flexible and versatile maintenance strategy, in both coating and repair applications, to prolong the operational lifetime of critical components for the railway industry.

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49

Molyneux-Berry, Paul, Claire Davis y Adam Bevan. "The Influence of Wheel/Rail Contact Conditions on the Microstructure and Hardness of Railway Wheels". Scientific World Journal 2014 (2014): 1–16. http://dx.doi.org/10.1155/2014/209752.

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The susceptibility of railway wheels to wear and rolling contact fatigue damage is influenced by the properties of the wheel material. These are influenced by the steel composition, wheel manufacturing process, and thermal and mechanical loading during operation. The in-service properties therefore vary with depth below the surface and with position across the wheel tread. This paper discusses the stress history at the wheel/rail contact (derived from dynamic simulations) and observed variations in hardness and microstructure. It is shown that the hardness of an “in-service” wheel rim varies significantly, with three distinct effects. The underlying hardness trend with depth can be related to microstructural changes during manufacturing (proeutectoid ferrite fraction and pearlite lamellae spacing). The near-surface layer exhibits plastic flow and microstructural shear, especially in regions which experience high tangential forces when curving, with consequentially higher hardness values. Between 1 mm and 7 mm depth, the wheel/rail contacts cause stresses exceeding the material yield stress, leading to work hardening, without a macroscopic change in microstructure. These changes in material properties through the depth of the wheel rim would tend to increase the likelihood of crack initiation on wheels toward the end of their life. This correlates with observations from several train fleets.

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50

Hajizad, Omid, Ankit Kumar, Zili Li, Roumen H. Petrov, Jilt Sietsma y Rolf Dollevoet. "Influence of Microstructure on Mechanical Properties of Bainitic Steels in Railway Applications". Metals 9, n.º 7 (11 de julio de 2019): 778. http://dx.doi.org/10.3390/met9070778.

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Wheel–rail contact creates high stresses in both rails and wheels, which can lead to different damage, such as plastic deformation, wear and rolling contact fatigue (RCF). It is important to use high-quality steels that are resistant to these damages. Mechanical properties and failure of steels are determined by various microstructural features, such as grain size, phase fraction, as well as spatial distribution and morphology of these phases in the microstructure. To quantify the mechanical behavior of bainitic rail steels, uniaxial tensile experiments and hardness measurements were performed. In order to characterize the influence of microstructure on the mechanical behavior, various microscopy techniques, such as light optical microscopy (LOM), scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD), were used. Three bainitic grades industrially known as B360, B1400 plus and Cr-Bainitic together with commonly used R350HT pearlitic grade were studied. Influence of isothermal bainitic heat treatment on the microstructure and mechanical properties of the bainitic grades was investigated and compared with B360, B1400 plus, Cr-Bainitic and R350HT in as-received (AR) condition from the industry. The results show that the carbide-free bainitic steel (B360) after an isothermal heat treatment offers the best mechanical performance among these steels due to a very fine, carbide-free bainitic microstructure consisting of bainitic ferrite and retained austenite laths.

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