Download or read book Thermal and Thermoelastic Effects in Rolling Sliding Contacts written by T. A. Dow and published by . This book was released on 1984 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes a theoretical and experimental study of thermal and thermomechanical effects on frictionally and electrically heated rolling/sliding surfaces. A 2-D thermal analysis is used to predict the temperature distribution through the thickness of the lubricant film in an elastohydrodynamic (EHD) contact. The relative magnitude of shear and compressive heating as well as the losses due to conduction and convection are compared for pure rolling and slip conditions. Originator-supplied key words include: Tribology, Elastohydrodynamic lubrication, Electrical brush, Wear, Thermal effects, Thermomechanical effects, Lubricant rheology, and High current density monolithic electrical brushes.
Download or read book Thermal and Thermomechanical Effects in Rolling Sliding Contacts written by T. A. Dow and published by . This book was released on 1981 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: The program involved analysis and experimentation relating to thermal effects in two important systems: elastohydrodynamically (EHD) lubricated bearings or gears, and high-current-density electrical brushes. A thermodynamic heat balance has been applied to an EHD contact utilizing experimental values for surface pressure and temperature distributions. The results showed that the magnitude of compressive and shear heating in the lubricant were higher than that due to convection to the fluid. Experimental measurements of axial film thickness profiles for rolling/sliding disks were made using an X-ray shadow technique. The objective was to determine if the profile under load will vary due to nonuniform heating and thermal expansion at the disk contact leading to scuffing failure. No significant changes in profile were measured, but a limited range of experimental conditions were studied. A high-current-density electrical slip ring apparatus was constructed and used to study the effect of material properties on the contact between the stationary brush and the copper slip ring. The results showed that above a particular threshold speed, the brushes exhibited a sparking phenomenon which consisted of periodic motion of a cluster of small sparks at the brush/slip ring interface.
Download or read book Thermal and Chemical Effects in High Pressure Rolling Sliding Contacts written by J. w Brasch and published by . This book was released on 1981 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a previous report to the Office of Naval Research, several thermal and thermomechanical aspects of tribology pertinent to rolling/sliding contacts were described in some detail. In this final report, there is presented an account of related work on surface chemical reactions occurring at high pressures. A model lubricant system - lauric acid in dodecane - in contact with a simulated bearing surface - thin films of vacuum-deposited iron - was employed in these studies. Fourier transform infrared spectroscopy was used to detect the formation of species arising from chemical reactions occurring between the acid molecules and the substrate. Details of the experimental technique and its application to the present program are given. (Author).
Download or read book Modern Tribology Handbook Two Volume Set written by Bharat Bhushan and published by CRC Press. This book was released on 2000-12-28 with total page 1760 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent research has led to a deeper understanding of the nature and consequences of interactions between materials on an atomic scale. The results have resonated throughout the field of tribology. For example, new applications require detailed understanding of the tribological process on macro- and microscales and new knowledge guides the rational
Download or read book Thermal and Non Newtonian Effects in Elastohydrodynamic Lubrication of Rolling sliding Contacts written by Moosa Zand and published by . This book was released on 1990 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 1572 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermal Effects of Concentrated Sliding rolling Line Contacts and Their Relation to Scuffing Wear written by Sui-Wah Siu and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermal Effects of Concentrated Sliding rolling Line Contacts and Their Relation to Scuffing Wear written by S. W. Siu and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermomechanical Effects in Wear written by and published by . This book was released on 1982 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Abstract Bulletin written by and published by . This book was released on 1981 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Engineering Tribology written by Gwidon Stachowiak and published by Butterworth-Heinemann. This book was released on 2013-09-16 with total page 883 pages. Available in PDF, EPUB and Kindle. Book excerpt: Engineering Tribology, Fourth Edition is an established introductory reference focusing on the key concepts and engineering implications of tribology. Taking an interdisciplinary view, the book brings together the relevant knowledge from different fields needed to achieve effective analysis and control of friction and wear. Updated to cover recent advances in tribology, this new edition includes new sections on ionic and mesogenic lubricants, surface texturing, and multiscale characterization of 3D surfaces and coatings. Current trends in nanotribology are discussed, such as those relating to lubricants, coatings and composites, and geotribology is introduced. Suitable as an introductory text, a refresher or an on-the-job reference, Engineering Tribology, 4th Edition is intended for final year undergraduate and postgraduate students in mechanical engineering as well as professional engineers. It is also relevant to those working in materials engineering, applied chemistry, physics and bioengineering. Offers a comprehensive overview of the mechanisms of wear, lubrication and friction in an accessible manner designed to aid novice engineers, non-specialists and students Provides a reader-friendly approach to the subject using illustrations to break down the typically complex problems associated with tribology Includes end-of-chapter problems to test understanding
Download or read book Mechanical and Thermal Effects in Electrically Heated Sliding Contacts written by Younggill Yune and published by . This book was released on 1988 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Engineering Tribology written by G.W. Stachowiak and published by Butterworth-Heinemann. This book was released on 1993-06-30 with total page 901 pages. Available in PDF, EPUB and Kindle. Book excerpt: The interdisciplinary nature of tribology encompasses knowledge drawn from disciplines such as mechanical engineering, materials science, chemistry and physics. The interaction between these different fields of knowledge to achieve the final result, the control of friction and wear, is reviewed in this volume. This interdisciplinary approach has proven to be a very successful way of analysing friction and wear problems. In many cases tribology is viewed as an inaccessible subject which does not produce useful answers. In this volume the authors redress this problem by providing a comprehensive treatment of the subject. A basic feature of the book is the emphasis on describing various concepts in an accessible manner for the benefit of non-specialists. This principle is applied from the beginning of the book, where the reader is introduced to the fundamental concept of tribology. This concept is then often used to show how the various topics in tribology are interrelated to form one coherent subject. A direct graphical illustration of the mechanisms controlling tribological phenomena is presented. Carefully prepared diagrams allow rapid appreciation of the basic ideas and facts in tribology. The numerical analysis of hydrodynamic lubrication is supported by a number of computer programs which are included in the book. The control of wear is given extensive treatment with a thorough discussion of lubricant additives, solid lubricants and surface coatings. The effectiveness of coatings in suppressing specific forms of wear is analyzed together with the methods of coatings deposition. The book contains 474 figures and 44 tables. More than 1000 references are provided to give the reader access to more specialized information if required. The volume is intended to provide graduates in engineering or materials science with an understanding of the fundamental concepts of friction, wear and lubrication.
Download or read book Thermomechanical Effects in Sliding Wear written by Ralph A. Burton and published by . This book was released on 1978 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: When sliding occurs with significant frictional heating, thermoelastic deformation may lead to a transition from smoothly distributed asperity contact to a condition where the surfaces are supported by a few thermal asperities. This circumstance may be associated with a transition to a condition of severe wear because of the elevated contact pressure and temperature, and also because of production of tensile stresses. This second stress component may lead to heat checking whereupon the rough checked surface acts to abrade the mating material. The factors influencing transition are discussed, including wear, cooling, and hydrodynamic lubrication. The transitioned state is also discussed as to stress distribution, rate of movement of the contact patches and temperatures. (Author).
Download or read book Thermal Effects in Rolling Sliding Contact written by T. A. Dow and published by . This book was released on 1982 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report discusses the results of a series of pressure and temperature distributions measured between a pair of elastohydrodynamically (EHD) lubricated disks. Three lubricants have been studied: a synthetic paraffinic oil (XRM-109F), polyphenyl ether (OS-124), and a traction fluid (Santotrac 50). Pressure and temperature readings throughout the contact are presented as three-dimensional plots. Measurements of the EHD film thickness, and the tractive force between disks under slip conditions are also presented. A method for one-dimensional mapping of tractive force is introduced. An instrumental part of the method is the data handling capability of a digitizing oscilliscope which captures signals from the traction probe. The oscilliscope's capabilities are greatly expanded by a microprocessor which controls its functions. Preliminary results from this method of local traction measurement are presented. (Author).
Download or read book The Role of Thermoelastic Effects in the Scuffing Failure of Rolling Sliding EHD Contacts written by R. R. Johnson and published by . This book was released on 1988 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: A two-dimensional numerical solution of the thermal Reynolds', elasticity, and energy equations resulted in predictions of the flow velocities and temperatures within the lubricant film between a crown roller and a rotating shaft. The results showed a good agreement with previously measured experimental data on the surface temperatures in an EHD contact and on the resulting frictional torques for both rolling and sliding. A pressure and temperature dependent viscosity was assumed for the synthetic paraffinic hydrocarbon used in the experiments. This model allowed an evaluation of the relative importance of the generation, viscous dissipation, and compression terms in the energy equation at different stations along the mid-film line of contact. Based on the insight about the relative importance of terms as found in the numerical simulation, convenient expressions were developed for an approximate method of predicting the mid-film temperature and sliding friction force. The influence of thermal expansion of the contact between a crowned surface in sliding contact with a rotating cylindrical surface was included in a model of thermoelastic instability to predict the onset of scuffing failure. The simplified approach assumed a heat balance between the generation from friction and the heat conducted into the cylinders. (RH).
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1987 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:
