Download or read book Unbalance Response Prediction for Rotors on Ball Bearings Using Speed and Load Dependent Nonlinear Bearing Stiffness written by and published by . This book was released on 2003 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Unbalance Response Prediction for Rotors on Ball Bearings Using Speed and Load Dependent Nonlinear Bearing Stiffness written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-20 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rolling-element bearing forces vary nonlinearly with bearing deflection. Thus an accurate rotordynamic analysis requires that bearing forces corresponding to the actual bearing deflection be utilized. For this work bearing forces were calculated by COBRA-AHS, a recently developed rolling-element bearing analysis code. Bearing stiffness was found to be a strong function of bearing deflection, with higher deflection producing markedly higher stiffness. Curves fitted to the bearing data for a range of speeds and loads were supplied to a flexible rotor unbalance response analysis. The rotordynamic analysis showed that vibration response varied nonlinearly with the amount of rotor imbalance. Moreover, the increase in stiffness as critical speeds were approached caused a large increase in rotor and bearing vibration amplitude over part of the speed range compared to the case of constant bearing stiffness. Regions of bistable operation were possible, in which the amplitude at a given speed was much larger during rotor acceleration than during deceleration. A moderate amount of damping will eliminate the bistable region, but this damping is not inherent in ball bearings. Fleming, David P. and Poplawski, J. V. Glenn Research Center NASA/TM-2003-212527, E-14089, NAS 1.15:212527
Download or read book Nonlinear Dynamical Systems in Engineering written by Vasile Marinca and published by Springer Science & Business Media. This book was released on 2012-01-05 with total page 403 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents and extend different known methods to solve different types of strong nonlinearities encountered by engineering systems. A better knowledge of the classical methods presented in the first part lead to a better choice of the so-called “base functions”. These are absolutely necessary to obtain the auxiliary functions involved in the optimal approaches which are presented in the second part. Every chapter introduces a distinct approximate method applicable to nonlinear dynamical systems. Each approximate analytical approach is accompanied by representative examples related to nonlinear dynamical systems from to various fields of engineering.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1988 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Unbalance Response Prediction for Accelerating Rotors with Load Dependent Nonlinear Bearing Stiffness written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-24 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rolling-element bearing forces vary nonlinearly with bearing deflection. Thus an accurate rotordynamic analysis requires that bearing forces corresponding to the actual bearing deflection be utilized. Previous papers have explored the transient effect of suddenly applied imbalance and the steady-state unbalance response, using bearing forces calculated by the rolling-element bearing analysis code COBRA-AHS. The present work considers the acceleration of a rotor through one or more critical speeds. The rotordynamic analysis showed that for rapid acceleration rates the maximum response amplitude may be considerably less than predicted by steady-state analysis. Above the critical speed, transient vibration at the rotor natural frequency occurs, similar to that predicted for a Jeffcott rotor with constant-stiffness bearings. A moderate amount of damping will markedly reduce the vibration amplitude, but this damping is not inherent in ball bearings. Fleming, David P. and Sawicki, Jaezy T. and Poplawski, J. V. Glenn Research Center NASA/TM-2005-213801, E-15159
Download or read book Journal of Tribology written by and published by . This book was released on 1990 with total page 778 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of Mechanical Design written by and published by . This book was released on 1982 with total page 908 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International aerospace abstracts written by and published by . This book was released on 1993 with total page 1060 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 38th AIAA ASME SAE ASEE Joint Propulsion Conference Exhibit 02 4150 02 4199 written by and published by . This book was released on 2002 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rotor Systems written by Rajiv Tiwari and published by CRC Press. This book was released on 2017-11-22 with total page 1225 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this book is to give a basic understanding of rotor dynamics phenomena with the help of simple rotor models and subsequently, the modern analysis methods for real life rotor systems. This background will be helpful in the identification of rotor-bearing system parameters and its use in futuristic model-based condition monitoring and, fault diagnostics and prognostics. The book starts with introductory material for finite element methods and moves to linear and non-linear vibrations, continuous systems, vibration measurement techniques, signal processing and error analysis, general identification techniques in engineering systems, and MATLAB analysis of simple rotors. Key Features: • Covers both transfer matrix methods (TMM) and finite element methods (FEM) • Discusses transverse and torsional vibrations • Includes worked examples with simplicity of mathematical background and a modern numerical method approach • Explores the concepts of instability analysis and dynamic balancing • Provides a basic understanding of rotor dynamics phenomena with the help of simple rotor models including modern analysis methods for real life rotor systems.
Download or read book Dynamics of Rotors and Foundations written by Erwin Krämer and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rotordynamics are of great importance in the design, manufacture and assembly of turbomachines as well as in ensuring their safe operation. Also important are the dynamics of the foundation and its interaction with the dynamics of the rotor. This book is divided into four parts. Following a presentation of the basic theory the dynamics of rotors supported on several bearings. The third part describes the dynamics of foundations of turbine line-outs and the calculations for a turbomachine coupled with its foundation. The last part includes a section on estimation procedures, a comprehensive presentation of the theoryand practice of rotors having a transverse crack, a section on the mathematical fundamentals and a description of the computer program used for the examples in the book. The book addresses both the practical engineer and the theoretician and should provide manufacturers, operators, university and polytechnic lecturers and students with an understanding of the vibrations of turbomachines. The results are described in such a way that they can be easily understood and applied.
Download or read book ASME Technical Papers written by and published by . This book was released on 1998 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Paper written by and published by . This book was released on 1998 with total page 796 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Rotordynamics written by Fredric F. Ehrich and published by Krieger Publishing Company. This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented here is a comprehensive work on the general principles that apply to every type of modern rotating machinery. This handbook addresses both the theoretical and practical issues pertaining to the design, analysis, development, production, and maintenance of high-speed rotating machinery. It is the only work available that provides engineers with the information they need to anticipate, locate, and eliminate destructive vibration. This outstanding handbook contains chapters written by recognized experts in their respective fields, providing practical information on: vibration considerations in the design of rotating machinery; analytic prediction of rotordynamic response; balancing of flexible and rigid rotors; and performance verification, diagnostics, parameter identification, and vibration monitoring in rotating machinery. Covering the general principles that apply to every type of modern rotating machinery, the handbook is packed with specific examples about a wide array of equipment, including steam turbines, electrical motors, generators, aircraft gas turbines, reciprocating engines, and centrifuges. Fredric F. Ehrich, a registered professional engineer and a member of the National Academy of Engineering received his B.S., M.E., and Sc.D. degrees in Mechanical Engineering from M.I.T. He spent the majority of his career in the design and development of aircraft gas turbines at General Electric Aircraft Engines and earlier in the Aircraft Gas Turbine Division of the Westinghouse Co. Since his retirement, he has been active in research and teaching as a senior lecturer at M.I.T. and in consulting. Dr. Ehrich is the author of over 50 published technical papers on rotordynamics and related topics, and he holds nine issued patents on aircraft gas turbine apparatus.
Download or read book Japanese Science and Technology 1983 1984 written by United States. National Aeronautics and Space Administration. Scientific and Technical Information Branch and published by . This book was released on 1985 with total page 1080 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamics of Rotating Machines written by M. I. Friswell and published by Cambridge University Press. This book was released on 2010-03-31 with total page 545 pages. Available in PDF, EPUB and Kindle. Book excerpt: Enables engineers to understand the dynamics of rotating machines, from basic explanations to detailed numerical models and analysis.
Download or read book Dynamics of Rotating Systems written by Giancarlo Genta and published by Springer Science & Business Media. This book was released on 2007-01-04 with total page 674 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides an up-to-date review of rotor dynamics, dealing with basic topics as well as a number of specialized topics usually available only in journal articles Unlike other books on rotordynamics, this treats the entire machine as a system, with the rotor as just one component
