Author: Shung Sung
Publisher: Springer Nature
ISBN: 3031796896
Category : Technology & Engineering
Languages : en
Pages : 110
Book Description
This book describes the Asymptotic Modal Analysis (AMA) method to predict the high-frequency vibroacoustic response of structural and acoustical systems. The AMA method is based on taking the asymptotic limit of Classical Modal Analysis (CMA) as the number of modes in the structural system or acoustical system becomes large in a certain frequency bandwidth. While CMA requires both the computation of individual modes and a modal summation, AMA evaluates the averaged modal response only at a center frequency of the bandwidth and does not sum the individual contributions from each mode to obtain a final result. It is similar to Statistical Energy Analysis (SEA) in this respect. However, while SEA is limited to obtaining spatial averages or mean values (as it is a statistical method), AMA is derived systematically from CMA and can provide spatial information as well as estimates of the accuracy of the solution for a particular number of modes. A principal goal is to present the state-of-the-art of AMA and suggest where further developments may be possible. A short review of the CMA method as applied to structural and acoustical systems subjected to random excitation is first presented. Then the development of AMA is presented for an individual structural system and an individual acoustic cavity system, as well as a combined structural-acoustic system. The extension of AMA for treating coupled or multi-component systems is then described, followed by its application to nonlinear systems. Finally, the AMA method is summarized and potential further developments are discussed.
Asymptotic Modal Analysis of Structural and Acoustical Systems
Author: Shung Sung
Publisher: Springer Nature
ISBN: 3031796896
Category : Technology & Engineering
Languages : en
Pages : 110
Book Description
This book describes the Asymptotic Modal Analysis (AMA) method to predict the high-frequency vibroacoustic response of structural and acoustical systems. The AMA method is based on taking the asymptotic limit of Classical Modal Analysis (CMA) as the number of modes in the structural system or acoustical system becomes large in a certain frequency bandwidth. While CMA requires both the computation of individual modes and a modal summation, AMA evaluates the averaged modal response only at a center frequency of the bandwidth and does not sum the individual contributions from each mode to obtain a final result. It is similar to Statistical Energy Analysis (SEA) in this respect. However, while SEA is limited to obtaining spatial averages or mean values (as it is a statistical method), AMA is derived systematically from CMA and can provide spatial information as well as estimates of the accuracy of the solution for a particular number of modes. A principal goal is to present the state-of-the-art of AMA and suggest where further developments may be possible. A short review of the CMA method as applied to structural and acoustical systems subjected to random excitation is first presented. Then the development of AMA is presented for an individual structural system and an individual acoustic cavity system, as well as a combined structural-acoustic system. The extension of AMA for treating coupled or multi-component systems is then described, followed by its application to nonlinear systems. Finally, the AMA method is summarized and potential further developments are discussed.
Publisher: Springer Nature
ISBN: 3031796896
Category : Technology & Engineering
Languages : en
Pages : 110
Book Description
This book describes the Asymptotic Modal Analysis (AMA) method to predict the high-frequency vibroacoustic response of structural and acoustical systems. The AMA method is based on taking the asymptotic limit of Classical Modal Analysis (CMA) as the number of modes in the structural system or acoustical system becomes large in a certain frequency bandwidth. While CMA requires both the computation of individual modes and a modal summation, AMA evaluates the averaged modal response only at a center frequency of the bandwidth and does not sum the individual contributions from each mode to obtain a final result. It is similar to Statistical Energy Analysis (SEA) in this respect. However, while SEA is limited to obtaining spatial averages or mean values (as it is a statistical method), AMA is derived systematically from CMA and can provide spatial information as well as estimates of the accuracy of the solution for a particular number of modes. A principal goal is to present the state-of-the-art of AMA and suggest where further developments may be possible. A short review of the CMA method as applied to structural and acoustical systems subjected to random excitation is first presented. Then the development of AMA is presented for an individual structural system and an individual acoustic cavity system, as well as a combined structural-acoustic system. The extension of AMA for treating coupled or multi-component systems is then described, followed by its application to nonlinear systems. Finally, the AMA method is summarized and potential further developments are discussed.
Asymptotic Multiple Scale Method in Time Domain
Author: Jan Awrejcewicz
Publisher: CRC Press
ISBN: 100058125X
Category : Mathematics
Languages : en
Pages : 411
Book Description
This book offers up novel research which uses analytical approaches to explore nonlinear features exhibited by various dynamic processes. Relevant to disciplines across engineering and physics, the asymptotic method combined with the multiple scale method is shown to be an efficient and intuitive way to approach mechanics. Beginning with new material on the development of cutting-edge asymptotic methods and multiple scale methods, the book introduces this method in time domain and provides examples of vibrations of systems. Clearly written throughout, it uses innovative graphics to exemplify complex concepts such as nonlinear stationary and nonstationary processes, various resonances and jump pull-in phenomena. It also demonstrates the simplification of problems through using mathematical modelling, by employing the use of limiting phase trajectories to quantify nonlinear phenomena. Particularly relevant to structural mechanics, in rods, cables, beams, plates and shells, as well as mechanical objects commonly found in everyday devices such as mobile phones and cameras, the book shows how each system is modelled, and how it behaves under various conditions. It will be of interest to engineers and professionals in mechanical engineering and structural engineering, alongside those interested in vibrations and dynamics. It will also be useful to those studying engineering maths and physics.
Publisher: CRC Press
ISBN: 100058125X
Category : Mathematics
Languages : en
Pages : 411
Book Description
This book offers up novel research which uses analytical approaches to explore nonlinear features exhibited by various dynamic processes. Relevant to disciplines across engineering and physics, the asymptotic method combined with the multiple scale method is shown to be an efficient and intuitive way to approach mechanics. Beginning with new material on the development of cutting-edge asymptotic methods and multiple scale methods, the book introduces this method in time domain and provides examples of vibrations of systems. Clearly written throughout, it uses innovative graphics to exemplify complex concepts such as nonlinear stationary and nonstationary processes, various resonances and jump pull-in phenomena. It also demonstrates the simplification of problems through using mathematical modelling, by employing the use of limiting phase trajectories to quantify nonlinear phenomena. Particularly relevant to structural mechanics, in rods, cables, beams, plates and shells, as well as mechanical objects commonly found in everyday devices such as mobile phones and cameras, the book shows how each system is modelled, and how it behaves under various conditions. It will be of interest to engineers and professionals in mechanical engineering and structural engineering, alongside those interested in vibrations and dynamics. It will also be useful to those studying engineering maths and physics.
Vehicle Noise, Vibration, and Sound Quality
Author: Gang Sheng Chen
Publisher: SAE International
ISBN: 0768034841
Category : Technology & Engineering
Languages : en
Pages : 508
Book Description
This book gives readers a working knowledge of vehicle vibration, noise, and sound quality. The knowledge it imparts can be applied to analyze real-world problems and devise solutions that reduce vibration, control noise, and improve sound quality in all vehicles—ground, aerospace, rail, and marine. Also described and illustrated are fundamental principles, analytical formulations, design approaches, and testing techniques. Whole vehicle systems are discussed, as are individual components. The latest measurement and computation tools are presented to help readers with vehicle noise, vibration, and sound quality issues. The book opens with a presentation of the fundamentals of vibrations and basic acoustic concepts, as well as how to analyze, test, and control noise and vibrations. The next 2 chapters delve into noise and vibrations that emanate from powertrains, bodies, and chassis. The book finishes with an in-depth discussion on evaluating noise, vibration, and sound quality, giving readers a solid grounding in the fundamentals of the subject, as well as information they can apply to situations in their day-to-day work. This book is intended for: •Upper-level undergraduate and graduate students of vehicle engineering •Practicing engineers •Designers •Researchers •Educators
Publisher: SAE International
ISBN: 0768034841
Category : Technology & Engineering
Languages : en
Pages : 508
Book Description
This book gives readers a working knowledge of vehicle vibration, noise, and sound quality. The knowledge it imparts can be applied to analyze real-world problems and devise solutions that reduce vibration, control noise, and improve sound quality in all vehicles—ground, aerospace, rail, and marine. Also described and illustrated are fundamental principles, analytical formulations, design approaches, and testing techniques. Whole vehicle systems are discussed, as are individual components. The latest measurement and computation tools are presented to help readers with vehicle noise, vibration, and sound quality issues. The book opens with a presentation of the fundamentals of vibrations and basic acoustic concepts, as well as how to analyze, test, and control noise and vibrations. The next 2 chapters delve into noise and vibrations that emanate from powertrains, bodies, and chassis. The book finishes with an in-depth discussion on evaluating noise, vibration, and sound quality, giving readers a solid grounding in the fundamentals of the subject, as well as information they can apply to situations in their day-to-day work. This book is intended for: •Upper-level undergraduate and graduate students of vehicle engineering •Practicing engineers •Designers •Researchers •Educators
Government Reports Announcements & Index
Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 1098
Book Description
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 1098
Book Description
New Directions in Linear Acoustics and Vibration
Author: Matthew Wright
Publisher: Cambridge University Press
ISBN: 1139491547
Category : Science
Languages : en
Pages : 285
Book Description
Linear acoustics was thought to be fully encapsulated in physics texts of the 1950s, but this view has been changed by developments in physics during the last four decades. There is a significant new amount of theory that can be used to address problems in linear acoustics and vibration, but only a small amount of reported work does so. This book is an attempt to bridge the gap between theoreticians and practitioners, as well as the gap between quantum and acoustic. Tutorial chapters provide introductions to each of the major aspects of the physical theory and are written using the appropriate terminology of the acoustical community. The book will act as a quick-start guide to the new methods while providing a wide-ranging introduction to the physical concepts.
Publisher: Cambridge University Press
ISBN: 1139491547
Category : Science
Languages : en
Pages : 285
Book Description
Linear acoustics was thought to be fully encapsulated in physics texts of the 1950s, but this view has been changed by developments in physics during the last four decades. There is a significant new amount of theory that can be used to address problems in linear acoustics and vibration, but only a small amount of reported work does so. This book is an attempt to bridge the gap between theoreticians and practitioners, as well as the gap between quantum and acoustic. Tutorial chapters provide introductions to each of the major aspects of the physical theory and are written using the appropriate terminology of the acoustical community. The book will act as a quick-start guide to the new methods while providing a wide-ranging introduction to the physical concepts.
Vibration Transmission Through Rolling Element Bearings in Geared Rotor Systems
Author: Rajendra Singh
Publisher: DIANE Publishing
ISBN: 1428915540
Category : Bearings
Languages : en
Pages : 236
Book Description
A new mathematical model is proposed to examine the vibration transmission through rolling element bearings in geared rotor systems. Current bearing models, based on either ideal boundary conditions for the shaft or purely translational stiffness element description, cannot explain how the vibratory motion may be transmitted from the rotating shaft to the casing. For example, a vibration model based upon the simple bearing formulations can only predict purely in-plane type motion on the flexible casing plate given only bending motion on the shaft. However, experimental results have shown that the casing plate motion is primarily flexural. This study clarifies this issue qualitatively and quantitatively by developing a comprehensive bearing stiffness matrix is partially verified using available analytical and experimental data, and is completely characterized. This study extends the proposed bearing formulation to analyze the overall geared rotor system dynamics including casting and mounts. The bearing stiffness matrix is included in discrete system models using lumped parameter and/or dynamic finite element techniques. Eigensolution and forced harmonic response due to rotating mass unbalance or kinematic transmissions error excitation for the following examples are computed: (I) single-stage rotor system with flexible shaft supported by two bearings on rigid casing and flexible mounts, (II) spur gear pair system with motor and load inertials attached to two flexible shafts and supported by four bearings on flexibly mounted rigid casing, and (III) case II with flexible casing and rigid mounts. In several of these examples, analytical predictions compare well with measured data, validating the purposed formulation.
Publisher: DIANE Publishing
ISBN: 1428915540
Category : Bearings
Languages : en
Pages : 236
Book Description
A new mathematical model is proposed to examine the vibration transmission through rolling element bearings in geared rotor systems. Current bearing models, based on either ideal boundary conditions for the shaft or purely translational stiffness element description, cannot explain how the vibratory motion may be transmitted from the rotating shaft to the casing. For example, a vibration model based upon the simple bearing formulations can only predict purely in-plane type motion on the flexible casing plate given only bending motion on the shaft. However, experimental results have shown that the casing plate motion is primarily flexural. This study clarifies this issue qualitatively and quantitatively by developing a comprehensive bearing stiffness matrix is partially verified using available analytical and experimental data, and is completely characterized. This study extends the proposed bearing formulation to analyze the overall geared rotor system dynamics including casting and mounts. The bearing stiffness matrix is included in discrete system models using lumped parameter and/or dynamic finite element techniques. Eigensolution and forced harmonic response due to rotating mass unbalance or kinematic transmissions error excitation for the following examples are computed: (I) single-stage rotor system with flexible shaft supported by two bearings on rigid casing and flexible mounts, (II) spur gear pair system with motor and load inertials attached to two flexible shafts and supported by four bearings on flexibly mounted rigid casing, and (III) case II with flexible casing and rigid mounts. In several of these examples, analytical predictions compare well with measured data, validating the purposed formulation.
Dynamics of Very High Dimensional Systems
Author: E. H. Dowell
Publisher: World Scientific
ISBN: 9789812384676
Category : Technology & Engineering
Languages : en
Pages : 288
Book Description
Many books on dynamics start with a discussion of systems with one or two degrees of freedom and then turn to the generalization to the case of many degrees of freedom. For linear systems, the concept of eigenfunctions provides a compact and elegant method for decomposing the dynamics of a high dimensional system into a series of independent single-degree-of-freedom dynamical systems. Yet, when the system has a very high dimension, the determination of the eigenfunctions may be a distinct challenge, and when the dynamical system is nonconservative and/or nonlinear, the whole notion of uncoupled eigenmodes requires nontrivial extensions of classical methods. These issues constitute the subject of this book.
Publisher: World Scientific
ISBN: 9789812384676
Category : Technology & Engineering
Languages : en
Pages : 288
Book Description
Many books on dynamics start with a discussion of systems with one or two degrees of freedom and then turn to the generalization to the case of many degrees of freedom. For linear systems, the concept of eigenfunctions provides a compact and elegant method for decomposing the dynamics of a high dimensional system into a series of independent single-degree-of-freedom dynamical systems. Yet, when the system has a very high dimension, the determination of the eigenfunctions may be a distinct challenge, and when the dynamical system is nonconservative and/or nonlinear, the whole notion of uncoupled eigenmodes requires nontrivial extensions of classical methods. These issues constitute the subject of this book.
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 892
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 892
Book Description
The Shock and Vibration Digest
Author:
Publisher:
ISBN:
Category : Shock (Mechanics)
Languages : en
Pages : 492
Book Description
Publisher:
ISBN:
Category : Shock (Mechanics)
Languages : en
Pages : 492
Book Description
Dissertation Abstracts International
Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 800
Book Description
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 800
Book Description