Download or read book Rolling Contact Fatigue Testing Bearing Life Prediction and Steel Properties written by Thore B. Lund and published by . This book was released on 2012 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Few rolling bearing users realize that the fundamentals of bearing life predictions are based on experimental data derived under conditions very different from the ones generally used in RCF testing today. The basic life formulas derived in the 1940s largely were based on tests run on steel with very different characteristics than the materials used to produce bearing components today. Still, the fundamental life calculations are based on the (C/P)n concept, which was experimentally derived by Lundberg and Palmgren (Lundberg, G. and Palmgren, A., "Dynamic Capacity of Rolling Bearings," Acta Polytech. Scand., Mech. Eng. Ser., Volume 1, No. 3, 1947), even if the basic equation has been expanded and adjusted to reflect the lives recorded for modern bearings and to incorporate the concept of a fatigue limit (Ioannides, E., Bergling, G., and Gabelli, A., "An Analytical Formulation for the Life of Rolling Bearings," Acta Polytech. Scand., Mech. Eng. Ser., Volume 137, 1999, pp. 9-12, 21-24). In an attempt to better understand the premature and unpredictable failures that sometimes occur in certain industrial applications today, the test procedures used by Lundberg and Palmgren have been revisited, and data have been derived that might contribute to an understanding of the short lives sometimes experienced in certain industrial bearing applications. Based on this test procedure, a better understanding of the development of micro-crack associated plastic deformations at non-metallic inclusions also has been gained. The propensity of different non-metallic inclusions to drive the formation and growth of micro-cracks has been studied in detail, and this knowledge has been used to develop steel that is less prone to butterfly development and micro-crack growth under very high contact stress conditions. Today's bearing life prediction models presume that the Palmgren-Miner rule of accumulated damage is globally applicable. Experimental data questioning this assumption are presented.
Download or read book Rolling Contact Fatigue Testing of Bearings Steels written by J. J. C. Hoo and published by ASTM International. This book was released on 1982 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evolution of Mechanical Properties of M50 Bearing Steel Due to Rolling Contact Fatigue written by Bryan Allison and published by . This book was released on 2013 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current bearing life models significantly under predict the life of bearings made of modern ultra-clean steels. New life models that include the constitutive response of the material are needed. However, the constitutive response of bearing steel is known to change during bearing operation. In the current study, the evolution of the mechanical properties of M50 bearing steel due to rolling contact fatigue (RCF) was investigated. A combination of M50 balls and rods were subjected to RCF testing under various conditions (e.g. number of RCF cycles, applied Hertzian stress, and interacting material). Additionally, some of the balls tested went through a proprietary mechanical process to induce compressive residual stresses over the first several hundred microns into the depth of the ball prior to RCF testing. After RCF testing, the specimens were subjected to a number of tests. First, the residual stresses within the subsurface RCF affected region were measured via x-ray diffraction. The residual stresses within the mechanically processed (MP) balls were found to not significantly change due to RCF, while a linear relationship was found between the maximum residual stress with the RCF affected zone and the Hertzian stress for the unprocessed balls. Then, the specimens were sectioned, polished, and chemically etched to study the evolution of the microstructure due to RCF. A similar relationship was found between the size of the dark etching region (DER) and the Hertzian stress.
Download or read book Wheel Rail Interface Handbook written by R. Lewis and published by Elsevier. This book was released on 2009-09-25 with total page 865 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many of the engineering problems of particular importance to railways arise at interfaces and the safety-critical role of the wheel/rail interface is widely acknowledged. Better understanding of wheel/rail interfaces is therefore critical to improving the capacity, reliability and safety of the railway system. Wheel-rail interface handbook is a one-stop reference for railway engineering practitioners and academic researchers. Part one provides the fundamentals of contact mechanics, wear, fatigue and lubrication as well as state-of-the-art research and emerging technologies related to the wheel/rail interface and its management. Part two offers an overview of industrial practice from several different regions of the world, thereby providing an invaluable international perspective with practitioners’ experience of managing the wheel/rail interface in a variety of environments and circumstances. This comprehensive volume will enable practising railway engineers, in whatever discipline of railway engineering – infrastructure, vehicle design and safety, and so on – to enhance their understanding of wheel/rail issues, which have a major influence on the running of a reliable, efficient and safe railway. One-stop reference on the important topic of wheel rail-interfaces Presents the fundamentals of contact mechanics, wear, fatigue and lubrication Examines state-of-the-art research and emerging technologies related to wheel-rail interface and its management
Download or read book Ball and Roller Bearing Engineering written by Arvid Palmgren and published by . This book was released on 1959 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bearing Steel Technology written by John M. Beswick and published by ASTM International. This book was released on 2007 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bearing Steels written by J. J. C. Hoo and published by ASTM International. This book was released on 1975 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rolling Bearing Material Quality Fatigue Testing Material Quality Life Factors written by H. Krock and published by . This book was released on 2002 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rolling contact fatigue testing of low oxygen, high quality, rolling bearing steels is a major challenge to steel makers, bearing producers and end users. Material specimen based rolling contact fatigue tests were used for a number of years, mainly as acceptance tests. Often in this type of test, the applied contact stress exceeds the stress normally found in rolling bearing applications and also exceeds the limit stress for rapid cyclic micro-plastic groove formation in the rolling contact. For these reasons the established methods have limited ability to discriminate material quality effects in modern high cleanliness rolling bearing materials. Furthermore, the results of tests based on a material specimen are difficult to translate into life calculation factors for the bearings. In this paper a novel test method is presented and used to determine the effect of steel internal cleanliness on the performance of rolling bearings. To achieve this result considerable care is required in the preparation of the test elements, the selection of the specific test conditions and in the analysis of the results. This work also led to an ability to determine the dependence of steel quality on the steel making processes. Material cleanliness is characterized using the statistics of extreme values of the micro-inclusion size population allowing the steel cleanliness quality rating to be related directly to the fatigue performance of rolling bearings through the introduction of a material cleanliness factor ?. The expected bearing life performance for materials with different inclusion size ratings can thus be calculated. Results correlate well with measurements demonstrating that the quality rating of the material can now be reliably included in standard bearing life calculations.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metal Physics and Rolling Contact Fatigue Testing written by R. H. Vegter and published by . This book was released on 2012 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: A description of a novel rolling contact fatigue test for evaluation of bearing steel characteristics is presented. Unlike traditional approaches where bearings are tested until failure, the proposed testing method is based on monitoring the material response during testing. The measurement principles are based on changes of the surface geometry, such as grooving, because of accumulation of subsurface micro-plastic damage and on observations of related changes in the steel micro-structure. The test method is complemented by introducing a detailed material model that is used to model the groove development. The model is used to analyse the groove data and yields dedicated material property parameters, which can be used directly to model general material behaviour under rolling contact fatigue conditions. An example is given to illustrate the method and its use in assessing bearing steel performance.
Download or read book NASA Scientific and Technical Reports written by United States. National Aeronautics and Space Administration Scientific and Technical Information Division and published by . This book was released on 1967 with total page 2300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rolling Bearing Life Models and Steel Internal Cleanliness written by J. Beswick and published by . This book was released on 1999 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most widely used steel grade for rolling bearings is based on a steel composition first used almost a hundred years ago, the so-called lC-1.5Cr steel. This steel is used either in a selective surface induction hardened condition or in a through hardened heat treated condition, both yielding exceptional structural and contact fatigue properties. The Lundberg and Palmgren rolling bearing life prediction model, published in 1947, was the first analytical approach to bearing performance prediction, subsequently becoming a widely accepted basis for rolling bearing life calculations. At that time the fatigue life of rolling bearings was dominated by the classical sub-surface initiated failure mode. This mode results from the accumulation of micro-plastic strain at the depth of maximum Hertzian stress and is accelerated by the stress concentrations occurring at the micro internal defects. In common with all fatigue processes, rolling bearing failure is a statistical process: the failures of bearings with high inclusion content tested at high stress levels belong to the well-known family of "Weibull" distributions. Steady improvements in bearing steel cleanliness due, amongst other things, to the introduction of secondary metallurgy steel making techniques, have resulted in a significantly increased rolling bearing life and load carrying capacity. In recognition of this, in 1985 Ioannides and Harris introduced a new fatigue life model for rolling bearings, comprising a more widely applicable approach to the modelling of bearing life based on the relevant failure mode. Subsequently this has been extended to include effects of hardness and of micro-inclusion distributions in state-of-the-art clean bearing steel.
Download or read book Influence of Fiber Flow on Rolling Contact Fatigue Life written by A. Vincent and published by . This book was released on 2012 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bearings are some of the most important engineering components. Safety considerations mean that, for many applications, failure in service has to be avoided at all cost. It is thus critical to estimate the time a component will survive in service. In most cases, for steel bearing components, rolling contact fatigue (RCF) failures occur through initiation and propagation of cracks originating on non-metallic inclusions present in the steel (as a result of elaboration conditions). In this context, the inclusions distribution in a particular component is critical in determining its performance in RCF. Moreover, inclusions morphology and spatial distribution (e.g., stringers) have been shown to have a significant effect on RCF life. The present paper deals with the validation of a recent model [Stienon, A., Fazekas, A., Buffière, J. Y., Daguier, P., Merchi, F., and Vincent, A., "A New Methodology for Predicting Fatigue Properties of Bearing Steels: From X-Ray Micro-Tomography and Ultrasonic Measurements to the Bearing Lives Distribution," J. ASTM Int., Volume 7, No. 3, 2010], developed to predict RCF life on the basis of measured inclusions distributions and taking into account non-uniform spatial distributions. Results are compared with experimental data for the case of flat washer tests. It is shown that the model not only exhibits satisfactory agreement with experimental results, but also allows to correctly predict the influence of stringers orientation (and thus of fiber flow) on RCF life.
Download or read book A Selected Listing of NASA Scientific and Technical Reports for written by United States. National Aeronautics and Space Administration. Scientific and Technical Information Division and published by . This book was released on 1964 with total page 1156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Preliminary Studies of Rolling contact Fatigue Life of High temperature Bearing Materials written by Thomas L. Carter and published by . This book was released on 1958 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: A preliminary investigation of the of rolling-contact fatigue life of both races and balls of some promising high-temperature bearing materials were made at room temperature in the rolling-contact fatigue spin rig.
Download or read book Fatigue in Railway Infrastructure written by Mark Robinson and published by Elsevier. This book was released on 2009-08-20 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue is a major issue affecting safety and quality of service in the railway industry. This book reviews key aspects of this important subject. It begins by providing an overview of the subject, discussing fatigue at the wheel-rail interface and in other aspects of infrastructure. It then considers fatigue in railway and tramway track, looking at causes of potential failure in such areas as rails and fixings as well as sleepers. It also reviews failure points in structures such as embankments and cuttings. The book analyses fatigue in railway bridges, looking in particular at masonry arch bridges as well as metal and concrete bridges. Two final chapters review safety and reliability issues affecting escalators and lifts.Fatigue in railway infrastructure is a helpful reference for those in the railway industry responsible for infrastructure maintenance as well as those researching this important subject. Provides a concise review of fatigue in the railway infrastructure Examines the causes of potential failure in rails, fixings and sleepers Analyses fatigue in railway bridges including masonry arch, metal and concrete structures
Download or read book A Study of Some Factors Affecting Rolling contact Fatigue Life written by Thomas L. Carter and published by . This book was released on 1960 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Factors included bearing lubricants, non-metallic inclusions and material alloy composition.
