Academic literature on the topic 'Rolling contact loads'

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Journal articles on the topic "Rolling contact loads"

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Zhou, R. S., H. S. Cheng, and T. Mura. "Micropitting in Rolling and Sliding Contact Under Mixed Lubrication." Journal of Tribology 111, no. 4 (October 1, 1989): 605–13. http://dx.doi.org/10.1115/1.3261984.

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Based on morphological tests in rolling and sliding contact, the effect of surface film, the subsurface heavily dislocated layer, crack initiation, crack propagation, and micropitting have been investigated by using a two-disk rig. A micro-macro contact model is presented for surface pitting in rolling and sliding contacts. In this model the pressures related to asperity interaction and the subsurface stress map along whole contact area have been analyzed by superimposing the asperity contacting loads on the Hertzian load for a given specimen surface. Compared to the experimental results, this model is capable of predicting the onset of micropits for given mechanical and lubrication conditions. Cracking is assumed to occur when the accumulated strain energy of the dislocation reaches a critical value. A three-dimensional crack propagating model has also been used for pitting life prediction in rolling and sliding contact.
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Choi, Dong Chul, and Tae Wan Kim. "Contact Analysis for the Critical Shoulder Height in Angular Contact Ball Bearing." Advanced Materials Research 433-440 (January 2012): 538–43. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.538.

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A numerical method to determine the shoulder height in the angular contact ball bearing using 3D contact analysis is proposed. The load analysis of a ball bearing was performed to calculate the distributions of internal loads and contact angles of each rolling element. From the results of bearing load analysis and the contact geometry between ball and inner/outer raceway, 3D contact analyses are conducted. The developed algorithm is applied to an angular contact ball bearing for the automotive wheel. The critical axial loads which are not affected by edge in the present shoulder height are calculated. The critical shoulder heights are also determined when the bearing is subjected to a practical load.
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Sadeghi, Farshid, and Kyung-Hoon Kim. "Effects of a Single Bump or Dent in Time Dependent Thermal Line EHD Lubrication." Journal of Tribology 116, no. 1 (January 1, 1994): 9–20. http://dx.doi.org/10.1115/1.2927055.

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A time-dependent thermal compressible elastohydrodynamic lubrication of line contact model has been developed to investigate the effects of a single bump or dent in heavily loaded rolling/sliding contacts. The results illustrate the transient behavior of the film thickness, pressure and temperature distributions as a bump or a dent travels through the contact. The multigrid multilevel technique was used to simultaneously solve the discretized time dependent Reynolds, elasticity and energy equations. The effects of various loads and speeds have been investigated. Results are presented for the nondimensional loads of W = 1.3 × 10−4, 2.3 × 10−4 and nondimensional speeds ranging from U = 1 × 10−11 to U = 10−10 under pure rolling and rolling/sliding conditions.
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Wirsching, Sven, and Marcel Bartz. "Using exact macroscopic geometry in elastohydrodynamic simulations of point and elliptical contacts." Tribologie und Schmierungstechnik 69, no. 5-6 (February 15, 2023): 54–61. http://dx.doi.org/10.24053/tus-2022-0045.

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In rib-guided roller bearings, there are a large number of different tribological contact forms. These include not only line contacts on the raceways, the cage and the rolling elements, but also point and elliptical contacts between the rolling element end face and the ring rib. Load is transmitted via these lubricated, concentrated rolling and rolling-sliding contacts. Depending on the load situation, these contacts contribute differently to the operating behavior of the roller bearing. Axial loads on rib-guided roller bearings are mainly transmitted via the point and elliptical contacts between the roller end and the ring rib. These oil-lubricated point and elliptical contacts can be calculated and designed using thermos-elastohydrodynamic (TEHD) simulations. In existing methods for the TEHD calculation of point and elliptical contacts, the macroscopic geometries of the contact partners are described in a simplified manner, similar to the theory according to HERTZ, using ellipsoids. However, contacts of real, complex geometry pairings of rolling elements and ribs, as used to optimize the axial load capacity or the frictional torque of roller bearings, can only be determined inaccurately with this method. Compared to the exact consideration of the macroscopic geometry, larger discrepancies in the lubricant film height, contact pressure and friction can be observed. For this reason, this paper presents a TEHD simulation that considers the exact macroscopic geometry of point or elliptical contacts. The macroscopic geometry is generated using mathematical functions and a ray-tracing method is used to generate the equivalent body for the TEHD simulation. Different geometry pairings of sphere, plane, cone and torus are investigated. The results for lubricant film height, contact pressure and friction are compared with the results from conventional TEHD simulations, which use a geometry description via ellipsoids. By comparing the calculated geometry pairings, the possibilities and limitations of the modified geometry description are assessed.
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Sun, Wei, Xiangxi Kong, Bo Wang, and Xingzhan Li. "Statics modeling and analysis of linear rolling guideway considering rolling balls contact." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 229, no. 1 (April 17, 2014): 168–79. http://dx.doi.org/10.1177/0954406214531943.

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The linear rolling guideway is composed of rail, carriage, rolling balls, and other accessories and contains a large number of rolling interfaces between the rolling balls and the grooves. For such a complex nonlinear mechanical system, it is very significant to obtain the statics deformation and vertical stiffness under different loads for the structural design of guideway and mechanical analysis of Computer Numerical Control (CNC) machine tool. Therefore, the focus of this study is on the development of statics modeling techniques of the linear rolling guideway by analytical and finite element methods, considering the rolling balls contact. First, an accurate statics analytical modeling method was proposed by using the Hertz contact theory and revision of experiment results. Then, on the basis of considering contacts between rolling balls and grooves, the precise finite element modeling was studied. To improve the efficiency of analysis, the full finite element model of guideway was replaced by the component finite element model. At last, the created analytical and component finite element models were applied to analyze the effects of load and preload on the statics characteristics of single ball and the whole guideway system. The proposal of current study may provide a reference to create the precise dynamics model of linear rolling guideway.
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Kumar, S., and S. P. Singh. "Threshold Stress Criterion in New Wheel/Rail Interaction for Limiting Rail Damage Under Heavy Axle Loads." Journal of Engineering for Industry 114, no. 3 (August 1, 1992): 284–88. http://dx.doi.org/10.1115/1.2899793.

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This paper presents a qualitative discussion of the effects of increasing new (initial) wheel-rail contact stresses on the degree of damage to the rail due to heavy axle loads. The importance and need of heavy axle loads and its relationship to rail damage as a result of the increasing wheel-rail contact stresses is discussed. Various mechanisms of energy absorption/losses due to free rolling and modes of rail damage are presented. These modes include surface and internal damage due to wear, contact shear, plasticity, fatigue, shelling, crack formation, etc. The concept of threshold stress observed in free rolling friction much earlier by Drutowski is discussed and analyzed. It is believed by the authors that the threshold stress is s material property. This concept of threshold stress, based on sharply increased rates of wear in free rolling contact, is then presented and analyzed. Considerations of increased plasticity-region development, due to increasing contact stresses and their relationship to increased rates of wear seen in experiments, is utilized to determine an upper bound of contact stresses for new wheel and rail under heavy axle load conditions. It is indicated that new wheel-rail profiles, which will achieve contact stresses below the threshold stress, will enable the U.S. railroads to carry heavy axle loads without serious future damage to the rails. It is concluded that a satisfactory solution for maintaining rail integrity under heavy axle loads is possible with proper design accompanied with laboratory experimentation for the new steels as they may be used in the rails.
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Houpert, L. "Piezoviscous-Rigid Rolling and Sliding Traction Forces, Application: The Rolling Element–Cage Pocket Contact." Journal of Tribology 109, no. 2 (April 1, 1987): 363–70. http://dx.doi.org/10.1115/1.3261367.

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Piezoviscous Rigid (PVR) film thicknesses, rolling and sliding traction forces formulas for the line and point contact case have been derived. They have been used to study the Rolling Element (R.E.)–cage pocket contact mechanism. As the R.E. gets closer to the cage web, the lubrication regime change gradually from the PVR regime to Piezoviscous Elastic (PVE or EHD) regime when steel cages are used. If plastic cages are used, the lubrication regime moves from the Isoviscous Elastic (IVE) regime to EHD regime. For the conditions simulated herein, the transition occurs at typical film thickness values of the order of 0.5 micrometers and substantially large loads can be calculated in the R.E.–steel cage contact. They can be of the order of 100 N at the transition. In many circumstances, the PVR regime prevails and the braking moment due to hydrodynamic traction in the contact can be easily calculated. A tight osculation between the R.E. and the cage pocket will increase significantly the load and braking moment on the R.E. Starvation effects are also estimated and cause a reduction of the load, but not of the braking moment.
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Ghalme, Sachin G. "Probabilistic Life Models in Rolling Contact Fatigue." Advanced Materials Research 433-440 (January 2012): 58–62. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.58.

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Rolling contact fatigue (RCF) is the name given to crack growth and material damage generated as a result of high loads transmitted between two surfaces which are rolling with relative to each other. An understanding of rolling contact fatigue failure mechanism and a prediction of lifetimes are of interest to both manufacturer and researcher. Subsurface originated cracks have been recognized as one of the main modes of failure for rolling contact fatigue (RCF) of bearings. Numbers of investigators have attempted to determine the physical mechanism involved in rolling contact fatigue of bearings and proposed models to predict their fatigue lives. This paper attempts to cover the most widely used probabilistic life models used in RCF.
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Li, Junning, Jiafan Xue, Ka Han, Qian Wang, and Wuge Chen. "Experimental Analysis on Skid Damage of Roller Bearing with the Time-Varying Slip and Temperature Distribution." Applied Sciences 10, no. 1 (December 18, 2019): 9. http://dx.doi.org/10.3390/app10010009.

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Skid damage affects the performance of aviation bearing, which covers different disciplines in tribology, thermology, materials science, dynamics, et al. In this manuscript, a novel horizontal skid damage test rig of a rolling bearing with higher rotation accuracy and better linear contact was built, which can simulate the rolling/sliding contact between the roller and inner ring. Combining with temperature, load, speed, slip, and surface microscopy, the skid damage mechanism of roller bearings was analyzed from a multi-information perspective. Meanwhile, the dynamic lubrication failure process of the contact pair in rolling bearings with the time-varying slip and temperature distribution was revealed. The effect of different radial loads, inner ring speeds, lubricating oil quantities, and states of cleanliness on the time-varying characteristics of the temperature and the slip of the rolling bearing were obtained. Among them, the radial load has the greatest influence on the slip rate of rolling bearing. In addition, the test results show that the skid damage under extremely light load is the comprehensive effect of adhesive wear and thermal failure.
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Li, Zhi, Jian Chen, Jiazhu Li, and Kun Liu. "Effect of textured surface on the frictional noise under line contact and sliding–rolling conditions." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 232, no. 9 (April 29, 2017): 1679–89. http://dx.doi.org/10.1177/0954406217706721.

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Line contact and sliding–rolling movements exist widely in gears and bearings. In order to investigate the influence of surface microstructure on the frictional noise, a numerical study on the frictional noise generated by textured surfaces under line contact and sliding–rolling conditions by the use of finite element method is presented. The finite element model is established based on real surface topography. To improve the analysis reliability, friction coefficients used in the simulation are measured for different textured surfaces under various loads and speeds. The relationship between the 3D surface topography parameters and the frictional noise are analyzed. Results show that the frictional noise under line contact sliding–rolling conditions increases with load and speed, which can be explained from an energy dissipation perspective. Moreover, the 3D surface topography parameters of mean peak curvature and peak density influence the frictional noise during sliding–rolling under line contact significantly.
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Dissertations / Theses on the topic "Rolling contact loads"

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Bulusu, Prashant. "Rolling contact fatigue predictions based on elastic-plastic finite element stress analysis and multiaxial fatigue /." abstract and full text PDF (free order & download UNR users only), 2006. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1437664.

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Thesis (M.S.)--University of Nevada, Reno, 2006.
"August, 2006." Includes bibliographical references (leaves 38-45). Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2006]. 1 microfilm reel ; 35 mm. Online version available on the World Wide Web.
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Naude, Francois Paulus. "Development of a methodology for calculating stresses in track components." Diss., Pretoria : [s.n.], 2004. http://upetd.up.ac.za/thesis/available/etd-07282005-090746.

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Dahlberg, Johan. "On the asperity point load mechanism for rolling contact fatigue." Doctoral thesis, Stockholm : Hållfasthetslära, Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4569.

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Hannes, Dave. "Modelling of surface initiated rolling contact fatigue crack growth using the asperity point load mechanism." Licentiate thesis, KTH, Hållfasthetslära (Avd.), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-34005.

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Hannes, Dave. "On fatigue crack growth modelling of surface initiated rolling contact fatigue using the asperity point load mechanism." Doctoral thesis, KTH, Hållfasthetslära (Avd.), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-141151.

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Load transfer in applications or between machine components is generally achieved through contact. In case of recurrent high contact loads in combination with a rolling motion, i.e. with a relatively small amount of slip, the contact surface may eventually suffer from rolling contact fatigue (RCF). The damage consists then of cracks and craters or spalls, which can cause dysfunctionality of the application leading to inefficiency or increased maintenance costs. Ultimately the damage may cause total failure of the machine component. The damage process is still not fully understood due to the complexity of the problem. Different mechanisms have been suggested to explain initiation and propagation of RCF damage. The current work focused on crack growth modelling of surface initiated RCF in case hardened gear steel. The study was based on the asperity point load mechanism, which emphasizes the importance of the surface roughness in the damage process. Asperities on the contact surface act as stress raisers inducing locally high tensile surface stress when entering the contact. Improved understanding of the damage process and further validation of the asperity point load mechanism was achieved. In Paper A, the crack path of surface initiated RCF was simulated in the symmetry plane of the damage with the trajectory of the largest principal stress in the uncracked material. The mode I fracture mechanism was found applicable as well as linear elastic fracture mechanics (LEFM). The evolvement of the asperity contact parameters during the load cycle was determined through a finite element (FE) contact model based on an equivalent contact geometry. The predicted RCF crack path agreed with experimental spall profiles both in entry details as in overall shape. An experimental series was performed in Paper B to investigate the crack closure behaviour in presence of large negative minimum loads. The experimental results suggested a crack closure limit close to zero. The choice of the equivalent mixed-mode stress intensity factor range and especially the crack closure limit had a significant effect on the predicted RCF or spalling life. The two-dimensional crack growth model was further developed in Paper C and used to investigate the influence of asperity size, friction and residual surface stress on the simulated RCF damage. The simulations agreed qualitatively with experimental observations where reduced surface roughness, improved lubrication and compressive residual surface stress increased RCF resistance. In Paper D, a three-dimensional stationary crack was studied using an FE model and a simplified RCF load. A new crack geometry was proposed allowing the investigation of the spall opening angle of the typical vshaped damage. Crack arrest through crack closure was suggested as explaining mechanism. A qualitative study indicated increased spread of the surface damage with increased friction. The results also depended on the crack inclination angle. The different studies supported the asperity point load mechanism to explain not only fatigue initiation but also fatigue crack propagation.

QC 20140210

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Anderson, Joshua. "Polycyclic Aromatic Hydrocarbon Release from Pavement Rejuvenators Due to Rolling Wheel Contact: An Investigation Using a Model Mobile Load Simulator." Digital WPI, 2019. https://digitalcommons.wpi.edu/etd-theses/1293.

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Polycyclic aromatic hydrocarbon (PAH) compounds, which are common to coal tar and coal-tar-based products, are ubiquitous environmental contaminates with carcinogenic effects to human health and aquatic life. Transport of PAHs via solid phase particulate motion, gaseous phase volatilization, and aqueous phase dissolution into urban waterbodies of PAH compounds from coal-tar-based pavement sealant products has been studied. Pavement rejuvenators are products applied to increase the usable life of pavement. Coal-tar-based rejuvenators contain a significantly larger mass fraction of coal-tar with respect to coal-tar-based sealants, but pavement rejuvenators have not been as extensively studied as pavement sealants. Chemical analysis of detached pavement material treated with coal-tar-bases, asphalt-based, and bio-based rejuvenators was conducted with gas chromatography – mass spectrometry (GC/MS) analysis for 16 PAH compounds and two aromatic heterocyclic organic compounds following extraction with methylene chloride. Detached pavement material was collected from 19 simulated asphalt surface abrasion experiments that used a model mobile load simulator (MMLS) test apparatus that replicated surface challenges from vehicular traffic. The MMLS test apparatus configuration allowed asphalt disc samples treated with different rejuvenation products, to be tested and for detached material to be collected and quantified prior to GC/MS analysis. Test cases evaluated the influence of rejuvenation product type and cure time, as well as the effect of sand application (simulating sand application during slippery winter storm conditions) had on detached particulate and ultimate PAH compound loading. The average mass of particulate detachment from samples following a 48 hour cure time, for the asphalt-based and coal-tar-based rejuvenator products were 0.347 g and 0.480 g, respectively. This mass of detached material was lower than that from pavement treated with bio-based rejuvenator and the control (not treated), which had 4.858 g and 2.567 g of detached particulate material, respectively. When the product cure time was increased to three weeks, which was significantly long enough to capture effects of compound volatilization, average particulate detachment increased to 0.882 g for the coal-tar-based rejuvenator and decreased for the bio-based rejuvenator to 2.600 g. Six tests performed with a single application of winter storm sand after a 48 hour product cure time showed an increase in average particulate detachment to 1.450 g and 0.617 g for pavement treated with the asphalt-based and coal-tar-based rejuvenators, respectively. Conversely, under the same conditions, a reduction in average detached particulate to 3.749 g was observed for the bio-based product. Detached particulate material quantities for each test case were used with the respective cumulative concentration of 16 PAH compounds quantified to make an assessment on the potential PAH compound contamination via solid phase particle transport. The average PAH compound concentration in particulate detached from pavement treated with a coal-tar-based rejuvenator was 3062.8 mg PAH per kg of particulate. This was an order of magnitude higher than the average PAH concentration measured in particulate detached from the two control pavement samples and the two asphalt-based samples after a 48 hour cure time, which were 322.1 and 508.1 mg PAH per kg detached particulate, respectively. PAH compound concentrations were also normalized by the surface area of pavement treated with a rejuvenator to determine the potential PAH compound contamination per unit area. Normalized results for each rejuvenator type were averaged to make an overall evaluation of the potential rejuvenator specific PAH compound loading. The coal-tar-based, bio-based, and asphalt-based rejuvenators had a normalized cumulative solid-phase PAH compound release of 2.35, 0.88, and 0.17 mg PAH per square foot of pavement rejuvenated, respectively. In addition, carbazole was quantified in all pavement samples treated with the coal-tar-based rejuvenator at an average concentration of 125.6 mg carbazole per kg detached particulate. Acridine was quantified in detached particulate from five of seven coal-tar-based test performed at an average concentration (excluding non-detection samples) of 42.1 mg acridine per kg detached particulate.
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Meziane, Bilel. "Film thickness build-up in highly loaded lubricated contacts under Zero Entrainment Velocity condition." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI005.

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Les contacts lubrifiés sous forte charge sont souvent étudiés dans des conditions de roulement/glissement. Dans ces cas, l’entrainement du lubrifiant dans un coin d’huile explique la présence d’un film séparateur. Cependant, il existe un certain nombre d’applications dans lesquelles les surfaces en contact ont des vitesses égales et opposées. Cela correspond à une vitesse d’entrainement (définie comme la moyenne des vitesses des deux surfaces) nulle. Dans ce cas, les modèles prédictifs de la littérature ne peuvent plus s’appliquer. Dans ce mémoire de thèse, les phénomènes physiques conduisant à une génération de film séparateur à vitesse d’entrainement nulle sont étudiés. Un modèle éléments finis prenant en compte les aspects thermiques et transitoires est mis en œuvre pour mesurer les quantités locales. En régime stationnaire, les résultats numériques sont comparés avec un très bon accord à un jeu de données issu d’une campagne d’expérimentations dédiée. Cette approche duale permet de quantifier l’influence de la charge, de la vitesse des surfaces et de la température externe sur l’épaisseur de film à vitesse d’entrainement nulle. Les contacts sont ensuite étudiés sous une charge variable, ce qui montre l’influence relative des phénomènes thermiques et transitoires pouvant générer une épaisseur de film. En fonction du ratio entre le temps caractéristique de chargement et le temps caractéristique d’échauffement, ces effets peuvent montrer une synergie bénéfique pour le contact
Highly loaded lubricated contacts are often studied in rolling/sliding conditions. In those cases, the entrainment of lubricant in a so-called “oil wedge” explains the existence of a separating film thickness. However, in a number of industrial applications, the contact is subjected to opposite surface velocities. In such cases, there is a Zero Entrainment Velocity (defined as the average velocity of the two surfaces) of the fluid. The film thickness prediction formulae developed in the literature for rolling contacts are unusable. In this thesis, the physical phenomena leading to a film build-up under Zero Entrainment Velocity condition are elucidated. A finite element model is used in order to facilitate in-situ measurements. It aims to describe the behaviour of the contact in thermal and transient conditions. In the stationary regime, the numerical values are compared with a very good agreement to a set of results obtained via a tailored experimental campaign. This dual approach enables a quantitative description of the influence of the contact load, surface velocities and external temperature on the film thickness under ZEV condition. Then, the relative influence of the thermal and squeeze effects is studied. Depending on the ratio between the characteristic loading time and the characteristic thermal time, these two effects can show a beneficial synergy for the contact
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Graux, Nicolas. "Caractérisation et modélisation des propriétés à la fatigue à grand nombre de cycles des aciers cémentés à partir d'essais d'auto-échauffement sous sollicitations cycliques." Thesis, Brest, 2017. http://www.theses.fr/2017BRES0104.

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Le dimensionnement en fatigue à grand nombre de cycles d'un contact roulant entre des éléments ayant subi un traitement thermochimique de cémentation s'avère rapidement complexe.D'une part le traitement de cémentation apporte une hétérogénéité de propriété dans les couches supérieures de la pièce qui dépend du protocole utilisé. D'autre part le chargement de contact roulant est un chargement complexe dont le mode de défaillance en fatigue s'initie en sous-couche.Afin de limiter le temps de la caractérisation des champs de propriétés en fatigue, l'utilisation des mesures d'auto-échauffement sous sollicitation cyclique ainsi que leur interprétation par un modèle probabiliste à deux échelles est proposé. Néanmoins de par l'hétérogénéité du matériau et de par la particularité du chargement il peut s'avérer délicat d'appliquer une telle méthode d'évaluation. ll est alors proposé d'explorer ces deux difficultés de manière séparé.Pour prendre en compte l'hétérogénéité matériaux, un protocole d'analyse de courbe d'auto-échauffement basé sur une variante d'un modèle probabiliste à deux échelles et sur les mesures de taux de carbone a été proposé. Les paramètres du modèle ont été identifiés sur une classe d'acier via des mesures d'auto-échauffement réalisées sur des éprouvettes représentatives de l'hétérogénéité du au traitement de cémentation. Enfin le modèle a été validé par comparaison avec des points de fatigue expérimentaux.En ce qui concerne le chargement de contact roulant, les difficultés pour réaliser une mesure d'auto-échauffement ont mené à effectuer une première campagne de mesure sur le cas intermédiaire du contact répété. A l'aide d'un modèle analytique simple, l'évolution du champ de température a pu être reliée à un terme source de chaleur moyen dont le lien avec les mécanismes de fatigue reste à démontrer. Finalement, des prototypes de machine de contact roulant dédiés aux mesures d'auto-échauffement ont été proposés. Les mesures réalisées sur ces dernières et leur interprétation laissent à penser qu'il sera possible d'identifier des propriétés de fatigue à partir de mesure d'auto-échauffement
The rolling contact fatigue prediction between two carburizing part quickly becomes complex.On one hand, the carburizing treatment give heterogeneous properties in surface layer depending on the treatment protocol. On the other hand, the rolling contact load is a complex load with a fatigue initiation in the sub-layer. To limit the duration of the field fatigue properties characterization, self-heating measurements under cycle load are used and their interpretation by a probabilistic two scales model is proposed. Nevertheless applying this fatigue evaluation method on heterogeneous material and for rolling contact load can be difficult. ln first approach those difficulties are split.To take into account the material heterogeneity, an analysis based on a variation of one probabilistic two scales model and on carbon rate measurement is proposed. Model parameters are identified on one steel class with self-heating measurement made on specimens representative of carburizing material heterogeneity. Finally the model is validated by comparison with experimental fatigue point.Making self-heating measurement for rolling contact load is complex. Consequently a first self-heating measurement campaign is made on the intermediary case of repeated contact. With a simple analytic model, the temperature field evolution can be linked to a mean heat source whose link with fatigue mechanism must be proven. Finally, rolling contact machine prototypes are proposed. Self-heating measurement made on those prototypes and their interpretation suggest that it will be possible to identify fatigue properties with self-heating measurement
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Books on the topic "Rolling contact loads"

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Jaschinski, Alfred. Anwendung der Kalkerschen Rollreibungstheorie zur dynamischen Simulation von Schienenfahrzeugen. Koln: DFVLR, 1987.

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Tielens, A. G. G. M. and United States. National Aeronautics and Space Administration., eds. Resistance to rolling in the adhesive contact of two elastic spheres. [Washington, DC: National Aeronautics and Space Administration, 1998.

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Tielens, A. G. G. M. and United States. National Aeronautics and Space Administration., eds. Resistance to rolling in the adhesive contact of two elastic spheres. [Washington, D.C: National Aeronautics and Space Administration, 1995.

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Kenis, William. Analysis of pavement structural variability. McLean, VA: U.S. Dept. of Transportation, Federal Highway Administration, Research and Development, Turner-Fairbank Highway Research Center, 1997.

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Zaretsky, Erwin V. Comparison of life theories for rolling-element bearings. [Washington, D.C.]: National Aeronautics and Space Administration, 1995.

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Zaretsky, Erwin V. Comparison of life theories for rolling-element bearings. [Washington, D.C.]: National Aeronautics and Space Administration, 1995.

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A rolling element tribometer for the study of liquid lubricants in vacuum. [Washington, DC]: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Program, 1996.

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Rolling contact fatigue of surface modified 440C using a "GE-polymet" type disc rod test rig. [Marshall Space Flight Center, Ala.]: National Aeronautics and Space Administration, George C. Marshall Space Flight Center, 1990.

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Scuffing characteristics of high-load rolling/sliding contacts operating in liquid oxygen: Effects of materials and surface roughness : technical report for the research conducted under grant/contract no. NAG8-1134. [Washington, DC: National Aeronautics and Space Administration, 1996.

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Book chapters on the topic "Rolling contact loads"

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Mutton, P. J., C. J. Epp, and J. Dudek. "Rolling contact fatigue in railway wheels under high axle loads." In Mechanics and Fatigue in Wheel/Rail Contact, 139–52. Elsevier, 1990. http://dx.doi.org/10.1016/b978-0-444-88774-0.50013-4.

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Senadhi, A. M. G. Binuri, Bodhita Bhattacharjee, and Vipin. "Analysis of Mechanical Characteristics of Non-Pneumatic Tyres." In Advances in Transdisciplinary Engineering. IOS Press, 2022. http://dx.doi.org/10.3233/atde220777.

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This research paper provides an analysis for the deformation and vertical stiffness of non-pneumatic tyres (NPT) due to different vertical loads. The non-pneumatic tyres are developed for replacing traditional pneumatic tyres. These tyres do not use air to support the load and subjected to hard conditions and rough terrain. The non-pneumatic tyres are used for heavy load-carrying capacity, vertical stiffness, contact pressure, and rolling. The mechanical characteristics of NPT are studied by using a 3D modelling software – Fusion 360 and analysed by using Finite Element Analysis (FEA) on the simulation software – Ansys.
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"Influence of wheel and rail profile shape on the initiation of rolling contact fatigue cracks at high axle loads." In The Dynamics of Vehicles on Roads and Tracks, 1194–203. CRC Press, 2016. http://dx.doi.org/10.1201/b21185-127.

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Mader, K., and J. Tomas. "Modelling of the Contact Behaviour Between Fine Adhesive Particles with Viscous Damping." In Discrete Element Modelling of Particulate Media, 76–85. The Royal Society of Chemistry, 2012. http://dx.doi.org/10.1039/bk9781849733601-00076.

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On the basis of reference particle systems the single contact of two smooth spherical particles is shown. The comprehensive force displacement models of elastic-plastic, adhesive and frictional contacts are discussed. Titania and micro glass particles are selected on basis of their different physical properties. Therefore the model “stiff particles with soft contacts” is used to quantify and compare the elastic-plastic and frictional contact properties. The varying adhesion forces between the particles directly depend on this “frozen” irreversible deformation. So the adhesion force depends on the previous normal force as a history parameter. The contribution of the load-dependent adhesion force to the tangential force in an elastic-plastic frictional contact, the rolling resistance and the torsional moment is also shown. In addition, the role of the contact consolidation coefficient is discussed. For relatively slow (quasistatic) motion and flow rates v < 1 m/s, the velocity-dependent damping force is assumed to be negligible. For processes with higher velocities, this assumption is not valid. Thus, the velocity-dependent viscous damping model by Tsuji et al. (Powder Technology, 1992,71,239-250.) was implemented into the contact model and simulated using Matlab.
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"The Mechanisms and Manifestations of Friction." In Tribomaterials, 13–46. ASM International, 2021. http://dx.doi.org/10.31399/asm.tb.tpsfwea.t59300013.

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Abstract This chapter reviews the types of friction that are of concern in tribological systems along with their associated causes and effects. It discusses some of the early discoveries that led to the development of friction laws and the understanding that friction is a system effect that can be analyzed based on energy dissipation. It describes the stick-slip behavior observed in wiper blades, the concept of asperities, and the significance of the shape, lay, roughness, and waviness of surfaces in sliding contact. It explains how friction forces are measured and how they are influenced by speed, load, and operating environment. It also covers rolling contact and fluid friction and the effect of lubrication.
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"Mechanical Testing." In Gear Materials, Properties, and Manufacture, 311–27. ASM International, 2005. http://dx.doi.org/10.31399/asm.tb.gmpm.t51250311.

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Abstract Mechanical tests are performed to evaluate the durability of gears under load. The chapter first discusses the processes involved in the computations of stress for test parameters of gear. Next, the chapter reviews the four areas of specimen characterization of a test program, namely dimensional, surface finish texture, metallurgical, and residual stress. The following section presents the tests that simulate gear action, namely the rolling contact fatigue test, the single-tooth fatigue test, the single-tooth single-overload test, and the single-tooth impact test. Finally, the chapter describes the test procedures for surface durability (pitting), root strength (bending), and scoring (or scuffing) testing.
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"Rolling-Contact Fatigue Failure of Type 440C Stainless Steel Radial-Contact Ball Bearings Because of Excessive Axial Load." In ASM Failure Analysis Case Histories: Mechanical and Machine Components. ASM International, 2019. http://dx.doi.org/10.31399/asm.fach.mech.c0047968.

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Tenberge, P., J. Vorgerd, and L. Gondecki. "2-disc tribometer for various tests on sliding/rolling contacts with tribological loads such as in tooth flank contacts." In International Conference on Gears 2022, 145–56. VDI Verlag, 2022. http://dx.doi.org/10.51202/9783181023891-145.

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Samantaray, Arun K., and Smitirupa Pradhan. "Dynamic Analysis of Steering Bogies." In Advances in Civil and Industrial Engineering, 524–79. IGI Global, 2016. http://dx.doi.org/10.4018/978-1-5225-0084-1.ch021.

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Running times of high-speed rolling stock can be reduced by increasing running speed on curved portions of the track. During curving, flange contact causes large lateral force, high frequency noises, flange wears and wheel load fluctuation at transition curves. To avoid derailment and hunting, and to improve ride comfort, i.e., to improve the curving performances at high speed, forced/active steering bogie design is studied in this chapter. The actively steered bogie is able to negotiate cant excess and deficiency. The bogie performance is studied on flexible irregular track with various levels of cant and wheel wear. The bogie and coach assembly models are developed in Adams VI-Rail software. This design can achieve operating speed up to 360 km/h on standard gauge ballasted track with 150mm super-elevation, 4km turning radius and 460m clothoid type entry curve design. The key features of the designed bogie are the graded circular wheel profiles, air-spring secondary suspension, chevron springs in the primary suspension, anti-yaw and lateral dampers, and the steering linkages.
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Conference papers on the topic "Rolling contact loads"

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Winkelmann, C., O. Woitschach, E. M. Meyer, and W. Lang. "Development of a strain sensor for rolling contact loads." In TRANSDUCERS 2011 - 2011 16th International Solid-State Sensors, Actuators and Microsystems Conference. IEEE, 2011. http://dx.doi.org/10.1109/transducers.2011.5969179.

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Cannon, Jesse R., Craig P. Lusk, and Larry L. Howell. "Compliant Rolling-Contact Element Mechanisms." In ASME 2005 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/detc2005-84073.

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This paper presents three planar mechanisms capable of performing the functions of a bearing and a spring: the compliant rolling-contact element (CORE), the CORE bearing, and the elliptical CORE bearing. The designs use compliant rolling-contact joints to achieve low friction rotation and to bear high in-plane lateral loads. A model for predicting the behavior of the designs is presented, and manufacturing considerations are discussed for the macro, meso, and micro scales. A case study is presented, and the designs are shown to be capable of meeting the demanding design constraints of the study.
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Darji, P. H., and D. P. Vakharia. "Stiffness Optimization of Hollow Cylindrical Rolling Element Bearing." In STLE/ASME 2008 International Joint Tribology Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/ijtc2008-71009.

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Since being originally introduced, cylindrical rolling element bearings have been significantly improved, in terms of their performance and working life. A major objective has been to decrease the Hertz contact stresses at the roller–raceway interfaces, because these are the most heavily stressed areas in a bearing. It has been shown that bearing life is inversely proportional to the stress raised to the ninth power (even higher). Investigators have proposed that under large normal loads a hollow element with a sufficiently thin wall thickness will deflect appreciably more than a solid element of the same size. An improvement in load distribution and thus load capacity may be realized, as well as contact stress is also reduced considerably by using a bearing with hollow rolling elements. Since for hollow rolling element no method is available for the calculation of contact stresses and deformation. The contact stresses in hollow members are often calculated by using the same equations and procedures as for solid specimens. This approach seems to be incorrect. Recently, the Finite Element Analysis (FEA) has been successfully used to evaluate contact problems for the roller bearings. Investigations have been made for hollow rollers in pure normal loading. Different hollowness percentages ranging from 0% to 90% have been analysed in FEA software to find the optimum percentage hollowness which gives minimum stress and finally longest fatigue life.
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Ghodrati, Mohamad, Mehdi Ahmadian, and Reza Mirzaeifar. "Studying the Effect of Tangential Forces on Rolling Contact Fatigue in Rails Considering Microstructure." In 2019 Joint Rail Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/jrc2019-1279.

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In this paper, the micro-mechanical mechanisms behind the initiation and propagation of rolling contact fatigue (RCF) damages caused by the large traction forces are investigated. This study provides a three-dimensional (3D) model for studying the rolling contact fatigue in rails. Since rolling contact fatigue is highly dependent on the rail’s steel microstructure behavior, a proper 3D approach to capture the microstructure- and orientation-dependent mechanical behavior is required. A precise material model known as crystal plasticity is used for this purpose. Additionally, a cohesive zone approach is implemented to capture the crack initiation and propagation at the grain boundaries. Using the 3D finite element model which is developed for this study, we evaluate the effect of various parameters such as traction forces along the rail, and also the normal forces on the RCF response. The results reveal that the RCF cracks initiate slightly below the rail surface. These cracks start propagating toward the rail surface when the contact force is applied in repeated load cycles. The results also indicate that the depth at which RCF initiates depends on the ratio between the longitudinal traction forces and the normal loads. With larger traction forces, the cracks initiate closer, or at the rail surface, whereas larger normal loads promote the cracks initiation beneath the surface.
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Darji, P. H., and D. P. Vakharia. "Determination of Optimum Hollowness for Hollow Cylindrical Rolling Element Bearing." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-67294.

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Hollow-cylindrical-roller bearings are intended for light load applications, including all types of grinding, machining, and milling spindles. They use hollow cylindrical rollers instead of solid rollers. These provide significant advantages over standard bearings, such as reduced vibration, low-radial runout, better radial stiffness, higher operating speeds, and lower operating temperatures. Investigators have proposed that under large normal loads a hollow element with a sufficiently thin wall thickness will deflect appreciably more than a solid element of the same size. An improvement in load distribution and thus load capacity may be realized, as well as contact stress is also reduced considerably by using a bearing with hollow rolling elements. Since for hollow rolling element no method is available for the calculation of contact stresses and deformation. The contact stresses in hollow members are often calculated by using the same equations and procedures as for solid specimens. This approach seems to be incorrect. Recently, the Finite Element Analysis (FEA) has been successfully used to evaluate contact problems for the roller bearings. Investigations have been made for hollow rollers in pure normal loading. Different hollowness percentages ranging from 0% and 30% to 80% have been analysed in FEA software to find the optimum percentage hollowness which gives minimum stress and finally longest fatigue life.
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Mason, Michael A., Charles P. Cartin, Parham Shahidi, Mark W. Fetty, and Brent M. Wilson. "Hertzian Contact Stress Modeling in Railway Bearings for Assorted Load Conditions and Geometries." In 2014 Joint Rail Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/jrc2014-3846.

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Increasing freight car loads demand higher performance tapered roller bearings. As the stress state on railway bearing applications continues to increase, further advancement in the modeling tools and methods used for subsurface contact stress evaluations are needed. Heat treat specifications and contact geometries for railway bearings were originally developed for ideal load conditions. However, in railroad applications, tapered roller bearings are exposed to a vast range of load conditions that are seldom perfect. Moreover, when comparing global rail markets, there are often differences in bearing loads, railcar wear conditions, maintenance practices, and reliability versus utilization expectations. Advanced modeling techniques need to be developed by bearing designers in order to meet the specific needs of each individual rail market. Prior research has shown that subsurface stresses, resulting from rolling contact, are the primary factor in the development of fatigue cracks in railway bearings. In addition, finite element modeling software has previously been used to analyze Hertzian contact stresses under rolling contact. Recent advancements in the technology and computational power of finite element methods can be used to numerically analyze more detailed simulations of complex geometries and biased load conditions in railway bearings. These improvements in the tapered roller bearing modeling methodology are necessary to determine the material, heat treat specifications, and geometry required to meet the demands of specific railway bearing applications. Furthermore, the specific risks associated with some common railway bearing design and modeling assumptions will be evaluated. An exploratory list of these assumptions include: line versus point contact, load deflection factor, zero contact angle, rigid body assumptions, linear material behavior, neglect for overload, and uniform loading on the bearing. Emphasis will be placed on potential improvements in the theoretical and finite element prediction of surface and subsurface stresses in railway bearings under rolling contact with a review of prior research on the subject.
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Cakdi, Sabri, Scott Cummings, and John Punwani. "Heavy Haul Coal Car Wheel Load Environment: Rolling Contact Fatigue Investigation." In 2015 Joint Rail Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/jrc2015-5640.

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Railway wheels and rails do not achieve full wear life expectancy due to the combination of wear, plastic deformation, and surface, subsurface, and deep subsurface cracks. Sixty-seven percent of wheel replacement and maintenance in North America is associated with tread damage [1]. Spalling and shelling are the two major types of wheel tread damage observed in railroad operations. Spalling and slid flat defects occur due to skidded or sliding wheels caused by, in general, unreleased brakes. Tread shelling (surface or shallow subsurface fatigue) occurs due to cyclic normal and traction loads that can generate rolling contact fatigue (RCF). Shelling comprises about half of tread damage related wheel replacement and maintenance. The annual problem size associated with wheel tread RCF is estimated to be in the tens of millions of dollars. The total cost includes maintenance, replacement, train delays and fuel consumption. To study the conditions under which RCF damage accumulates, a 36-ton axle load aluminum body coal car was instrumented with a high accuracy instrumented wheelset (IWS), an unmanned data acquisition (UDAC) system, and a GPS receiver. This railcar was sent to coal service between a coal mine and power plant, and traveled approximately 1,300 miles in the fully loaded condition on each trip. Longitudinal, lateral, and vertical wheel-rail forces were recorded continuously during four loaded trips over the same route using the same railcar and instrumentation. The first two trips were conducted with non-steering 3-piece trucks and the last two trips were conducted with passive steering M-976 compliant trucks to allow comparison of the wheel load environment and RCF accumulation between the truck types. RCF initiation predictions were made using “Shakedown Theory” [2]. Conducting two trips with each set of trucks allowed for analysis of the effects of imbalance speed conditions (cant deficiency or excess cant) at some curves on which the operating speeds varied significantly between trips.
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Niebuhr, D., M. Scholl, and P. Clayton. "Self-Lubricating Composite Plasma Sprayed Coatings." In ITSC 1996, edited by C. C. Berndt. ASM International, 1996. http://dx.doi.org/10.31399/asm.cp.itsc1996p0355.

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Abstract Composite self-lubricating coatings were developed using high-energy plasma spraying (HEPS). These coatings would be potentially used in high contact pressure rolling/sliding systems. The coatings are based on a steel coating deposited by high energy plasma spraying using wire feedstock. Solid lubricants such as graphite and soft metal were investigated. Twin roller rolling/sliding tests were performed at 5% and 35% creep and contact loads of 700 N to 1700 N on a 5 mm contact face. Reduced friction, compared to a steel coating-steel or 1080 wrought steel couple was observed under these rolling-sliding contact conditions.
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Zhang, Jun, Yingxi Liu, and Changhua Wu. "Analysis of Wheel-Rail Elasto-Plastic Contact Problem." In ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-33241.

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Using the finite element parametric quadratic programming method, computation of Elastic and Elastic-plastic rolling contact problems between wheel and rail is carried out for various cases such as different wheel diameters, different axle loads, different tractive force and different friction factors. The contact states and the contact internal force between wheel and rail are obtained, and their changing laws corresponding with every above-mentioned parameter are analyzed in this paper.
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Cummings, Scott, Richard Reiff, John Punwani, and Todd Snyder. "Measurement of Wheel/Rail Load Environment in Relation to Rolling Contact Fatigue." In 2011 Joint Rail Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/jrc2011-56020.

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Wheel shelling is the cause of a large portion of high impact wheels. The impact loads produced by shelled wheels can have a damaging effect on track components and rolling stock components such as roller bearings. Shelling is the result of accumulated rolling contact fatigue (RCF) on the wheel tread surface. To investigate the specific conditions in which RCF occurs, wheel load environment data was collected from a car with three-piece trucks running in revenue service. This data was analyzed in order to assess the predicted wheel RCF through the use of shakedown theory. An inspection team was dispatched to several track sites to record relevant information including a visual assessment of rail RCF, rail transverse profile, rail age, and friction conditions. Track inspections were conducted at locations where RCF was predicted and at nearby locations with similar curvature where RCF was not predicted. Conclusions from this work are the following: • The curve unbalance condition, which is a combination of curvature, track superelevation, and train speed, is an important factor in RCF. • Wheel/rail coefficient of friction in curves can be a factor in RCF. • Rail profile and track condition were not found to be major factors in this analysis. • Observed rail RCF condition correlated reasonably well with predictions when considering extenuating factors such as rail age and curve unbalance conditions. • Confidence was increased in previous simulation results involving three-piece trucks due to good correlation with the results of the current work. The simulation results suggest that the use of AAR approved M-976 trucks should reduce RCF. This work was funded by the Federal Railroad Administration (FRA) and the Wheel Defect Prevention Research Consortium (WDPRC), a group that includes railroads, private car owners, and industry suppliers.
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