Download or read book Thermoelastic Instability of Frictional Contacts written by Ralph A. Burton and published by . This book was released on 1970 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a study of the stability of frictional contact of elastic solids. To be specific, the problem is to determine when surface pressure or temperature distributions will be damped, or when they will be amplified by the thermal, frictional and elastic interactions of the surfaces. This effort will shed light on the behavior of numerous lubricated and unlubricated sliding systems such as seals, bearings, and piston rings. It should lead to design criteria in terms of materials and operating parameters. The present report is concerned with two phases of the study: (1) a discrete model of surface contact, and (2) a continuous thin-blade model of surface contact. The first sheds light on the processes at work, and analysis of it leads to a 'thermal vibration' equation with a damping coefficient which may be either negative or positive depending upon the specific operating conditions. The second model provides a more complete treatment of the thermoelastic interactions at work in continuous bodies. The work reported carries the analysis up through the derivation of a pair of algebraic equations involving the materials and operating parameters of the system. Because of the complex relationships involved, further work will be required to determine all of their implications. (Author).

Download or read book Friction and Instabilities written by J.A.C. Martinis and published by Springer. This book was released on 2014-05-04 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book addresses instability and bifurcation phenomena in frictional contact problems. The treatment of this subject has its roots in previous studies of instability and bifurcation in elastic, thermoelastic or elastic-plastic bodies, and in previous mathematical, mechanical and computational studies of unilateral problems. The salient feature of this book is to put together and develop concepts and tools for stability and bifurcation studies in mechanics, taking into account the inherent non-smoothness and non-associativity (non-symmetry) of unilateral frictional contact laws. The mechanical foundations, the mathematical theory and the computational algorithms for such studies are developed along six chapters written by the lecturers of a CISM course. Those concepts and tools are illustrated not only with enlightening academic examples but also with some demanding industrial applications, related, namely, to the automotive industry.

Download or read book Thermoelastic instabilities in sliding contact written by Thomas A. Dow and published by . This book was released on 1972 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermoelastic instability in rubbing contact is shown to be a consequence of the interaction of frictional heating, thermal expansion, conduction of heat from the contact zone, and wear. It manifests itself as a departure of the pressure distribution from a nominally uniform magnitude, as a result of the amplification of small disturbances. Such an instability is investigated here for two models of surface contact; (a) one-dimensional pin model and (b) two-dimensional blade model. The effects of materials, friction coefficients, severity of wear and sliding speed are delineated with respect to disturbance amplification or damping. The long-term growth of a disturbance is described and the resulting hot spot motion is explained. (Author).

Download or read book Nonsmooth Dynamics of Contacting Thermoelastic Bodies written by Jan Awrejcewicz and published by Springer Science & Business Media. This book was released on 2008-12-10 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work is devoted to an intensive study in contact mechanics, treating the nonsmooth dynamics of contacting bodies. Mathematical modeling is illustrated and discussed in numerous examples of engineering objects working in different kinematic and dynamic environments. Topics covered in five self-contained chapters examine non-steady dynamic phenomena which are determined by key factors: i.e., heat conduction, thermal stresses, and the amount of wearing. New to this monograph is the importance of the inertia factor, which is considered on par with thermal stresses. Nonsmooth Dynamics of Contacting Thermoelastic Bodies is an engaging accessible practical reference for engineers (civil, mechanical, industrial) and researchers in theoretical and applied mechanics, applied mathematics, physicists, and graduate students.

Download or read book Frictionally excited Thermoelastic Instability in Automotive Disk Brakes written by Kwangjin Lee and published by . This book was released on 1993 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transient Thermomechanical Deformation of Point Contacts Sliding with Dry Friction written by Hang-Seng Ng and published by . This book was released on 2009 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: The non-linear finite element program Abaqus will be used to simulate transient contact of a steel sphere sliding with friction against a rigid plane. The contact conditions include elastic and elastic/plastic deformation of the sphere. Both isothermal and thermomechanical conditions, i.e. with and without frictional heating are included. The contact radius, pressure distribution and temperature are tracked. From parametric studies, varying load, friction coefficient and material properties, dimensionless relationships will be developed. Comparison between the numerical studies and theoretical work under stricter conditions are made, where possible. Elastic and thermoelastic simulations agree with theory, although thermoelastic instabilities are found under conditions, where they are not normally expected. Under isothermal elastic/plastic conditions, the contact area during static load and sliding is larger than in the elastic case. Under thermoelasto-plastic sliding, we find interactions between thermomechanical instabilities (shrinking of the contact patch), thermal softening and plastic deformation, generally yielding contact sizes that may be somewhat larger than either the thermoelastic or the isothermal elastoplastic cases. We also find unexpected pressure and temperature distributions, even where contact sizes and pressure are close to the Hertzian, thermoelastic or elasto-plastic conditions. The thermomechanical elastic-plastic results can only be obtained by computational approach.

Download or read book Elastic and Thermoelastic Contact Problems with Friction and Wear written by and published by . This book was released on 1992 with total page 259 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Elastic and thermoelastic contact problems with friction and wear written by Lars Johansson and published by . This book was released on 1992 with total page 259 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book New Trends and Developments in Automotive System Engineering written by Marcello Chiaberge and published by BoD – Books on Demand. This book was released on 2011-01-08 with total page 681 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last few years the automobile design process is required to become more responsible and responsibly related to environmental needs. Basing the automotive design not only on the appearance, the visual appearance of the vehicle needs to be thought together and deeply integrated with the power developed by the engine. The purpose of this book is to try to present the new technologies development scenario, and not to give any indication about the direction that should be given to the research in this complex and multi-disciplinary challenging field.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Download or read book Noise and Vibration in Friction Systems written by Vladimir P. Sergienko and published by Springer. This book was released on 2014-09-30 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book analyzes the basic problems of oscillation processes and theoretical aspects of noise and vibration in friction systems. It presents generalized information available in literature data and results of the authors in vibroacoustics of friction joints, including car brakes and transmissions. The authors consider the main approaches to abatement of noise and vibration in non-stationary friction processes. Special attention is paid to materials science aspects, in particular to advanced composite materials used to improve the vibroacoustic characteristics of tribopairs The book is intended for researchers and technicians, students and post-graduates specializing in mechanical engineering, maintenance of machines and transport means, production certification, problems of friction and vibroacoustics.

Download or read book Friction Induced Vibrations and Self Organization written by Michael Nosonovsky and published by CRC Press. This book was released on 2013-08-09 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many scientists and engineers do not realize that, under certain conditions, friction can lead to the formation of new structures at the interface, including in situ tribofilms and various patterns. In turn, these structures-usually formed by destabilization of the stationary sliding regime-can lead to the reduction of friction and wear. Friction-I

Download or read book Models and Analysis of Quasistatic Contact written by Meir Shillor and published by Springer Science & Business Media. This book was released on 2004-09-16 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mathematical theory of contact mechanics is a growing field in engineering and scientific computing. This book is intended as a unified and readily accessible source for mathematicians, applied mathematicians, mechanicians, engineers and scientists, as well as advanced students. The first part describes models of the processes involved like friction, heat generation and thermal effects, wear, adhesion and damage. The second part presents many mathematical models of practical interest and demonstrates the close interaction and cross-fertilization between contact mechanics and the theory of variational inequalities. The last part reviews further results, gives many references to current research and discusses open problems and future developments. The book can be read by mechanical engineers interested in applications. In addition, some theorems and their proofs are given as examples for the mathematical tools used in the models.

Download or read book Contact Mechanics and Friction written by Valentin L. Popov and published by Springer Science & Business Media. This book was released on 2010-03-10 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: The English edition of “Contact Mechanics and Friction” lying before you is, for st the most part, the text of the 1 German edition (Springer Publishing, 2009). The book was expanded by the addition of a chapter on frictional problems in ear- quake research. Additionally, Chapter 15 was supplemented by a section on elasto-hydrodynamics. The problem sections of several chapters were enriched by the addition of new examples. This book would not have been possible without the active support of J. Gray, who translated it from the German edition. I would like to thank Prof. G. G. - charyan and Prof. S. Sobolev for discussions and critical comments on the chapter over earthquake dynamics. Dr. R. Heise made significant contributions to the - velopment and correction of new problems. I would like to convey my affecti- ate thanks to Dr. J. Starcevic for her complete support during the composition of this book. I want to thank Ms. Ch. Koll for her patience in creating figures and Dr. R. Heise, M. Popov, M. Heß, S. Kürscher, and B. Grzemba for their help in pro- reading. Berlin, November 2009 V.L. Popov Preface to the German Edition

Download or read book Fundamentals of Tribology and Bridging the Gap Between the Macro and Micro Nanoscales written by Bharat Bhushan and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 961 pages. Available in PDF, EPUB and Kindle. Book excerpt: The word tribology was fIrst reported in a landmark report by P. Jost in 1966 (Lubrication (Tribology)--A Report on the Present Position and Industry's Needs, Department of Education and Science, HMSO, London). Tribology is the science and technology of two interacting surfaces in relative motion and of related subjects and practices. The popular equivalent is friction, wear and lubrication. The economic impact of the better understanding of tribology of two interacting surfaces in relative motion is known to be immense. Losses resulting from ignorance of tribology amount in the United States alone to about 6 percent of its GNP or about $200 billion dollars per year (1966), and approximately one-third of the world's energy resources in present' use, appear as friction in one form or another. A fundamental understanding of the tribology of the head-medium interface in magnetic recording is crucial to the future growth of the $100 billion per year information storage industry. In the emerging microelectromechanical systems (MEMS) industry, tribology is also recognized as a limiting technology. The advent of new scanning probe microscopy (SPM) techniques (starting with the invention of the scanning tunneling microscope in 1981) to measure surface topography, adhesion, friction, wear, lubricant-fIlm thickness, mechanical properties all on a micro to nanometer scale, and to image lubricant molecules and the availability of supercomputers to conduct atomic-scale simulations has led to the development of a new fIeld referred to as Microtribology, Nanotribology, or Molecular Tribology (see B. Bhushan, J. N. Israelachvili and U.

Download or read book Contact Mechanics written by J.R. Barber and published by Springer. This book was released on 2018-02-09 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the solution of contact problems with an emphasis on idealized (mainly linear) elastic problems that can be treated with elementary analytical methods. General physical and mathematical features of these solutions are highlighted. Topics covered include the contact of rough surfaces and problems involving adhesive (e.g. van der Waals) forces. The author is a well-known researcher in the subject with hands-on experience of the topics covered and a reputation for lucid explanations. The target readership for the book includes researchers who encounter contact problems but whose primary focus is not contact mechanics. Coverage is also suitable for a graduate course in contact mechanics and end-of-chapter problems are included.

Download or read book Electrical Contacts written by Milenko Braunovic and published by CRC Press. This book was released on 2017-12-19 with total page 672 pages. Available in PDF, EPUB and Kindle. Book excerpt: Various factors affect the performance of electrical contacts, including tribological, mechanical, electrical, and materials aspects. Although these behaviors have been studied for many years, they are not widely used or understood in practice. Combining approaches used across the globe, Electrical Contacts: Fundamentals, Applications, and Technology integrates advances in research and development in the tribological, material, and analytical aspects of electrical contacts with new data on electrical current transfer at the micro- and nanoscales. Taking an application-oriented approach, the authors illustrate how material characteristics, tribological behavior, and loading impact the degradation of contacts, formation of intermetallics, and overall reliability and performance. Coverage is divided broadly into three sections, with the first focused on mechanics, tribology, materials, current and heat transfer, and basic reliability issues of electrical contacts. The next section explores applications, such as power connections, electronic connections, and sliding contacts, while the final section presents the diagnostic and monitoring techniques used to investigate and measure phenomena occurring at electrical contact interfaces. Numerous references to current literature reflect the fact that this book is the most comprehensive survey in the field. Explore an impressive collection of data, theory, and practical applications in Electrical Contacts: Fundamentals, Applications, and Technology, a critical tool for anyone investigating or designing electrical equipment with improved performance and reliability in mind.