Structural Vibration
Structural Vibration

Author: C. Beards

Publisher: Elsevier

Published: 1996-05-31

Total Pages: 289

ISBN-13: 0080518052

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Many structures suffer from unwanted vibrations and, although careful analysis at the design stage can minimise these, the vibration levels of many structures are excessive. In this book the entire range of methods of control, both by damping and by excitation, is described in a single volume.Clear and concise descriptions are given of the techniques for mathematically modelling real structures so that the equations which describe the motion of such structures can be derived. This approach leads to a comprehensive discussion of the analysis of typical models of vibrating structures excited by a range of periodic and random inputs. Careful consideration is also given to the sources of excitation, both internal and external, and the effects of isolation and transmissability. A major part of the book is devoted to damping of structures and many sources of damping are considered, as are the ways of changing damping using both active and passive methods. The numerous worked examples liberally distributed throughout the text, amplify and clarify the theoretical analysis presented. Particular attention is paid to the meaning and interpretation of results, further enhancing the scope and applications of analysis. Over 80 problems are included with answers and worked solutions to most. This book provides engineering students, designers and professional engineers with a detailed insight into the principles involved in the analysis and damping of structural vibration while presenting a sound theoretical basis for further study.Suitable for students of engineering to first degree level and for designers and practising engineersNumerous worked examplesClear and easy to follow

Vibration of Periodic Structures
Vibration of Periodic Structures

Author: Gautam SenGupta

Publisher: Elsevier

Published: 2023-10-27

Total Pages: 268

ISBN-13: 0323990231

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Vibration of Periodic Structures introduces the fundamentals of periodic structure theory by considering the simplest model – wave propagation in an infinitely long periodic spring-mass system. It then shows how the knowledge of the stop and pass bands can be utilized to find the natural frequency distribution in a finite periodic structure. The basic concepts are further extended to wave propagation in infinitely long periodically supported beams and plates; distribution of natural frequencies of a similar structure of finite length; vibration of skin-stringer structures; and structuralacoustic properties of a section of an aircraft fuselage, based on a combination of the finite element method and the periodic structure theory, in a highly cost-effective manner.This book is a valuable resource of information for practicing engineers in various industries, e.g., civil, mechanical, or aerospace engineering, dealing with vibration of structures with periodic properties, including prediction of supersonic flutter characteristics of aerospace structures. It will also prove to be a beneficial reference for researchers involved with wave propagation in metamaterials and phononic devices."Readers who have wanted a clear and connected account of vibration of periodic structures will find this treatment accessible and stimulating and will want to add this volume to their personal or institutional library. – Prof. Earl Dowell, Duke University, Durham, NC, USA - Shows how the periodic structure theory can be combined with the finite element method to model a section of an airplane fuselage to study its structural-acoustic characteristics - Features developing methods for predicting the dynamics of periodic structures in a cost-effective manner - Guides the reader to predict and reduce response of periodically stiffened structures to random excitations

Active and Passive Vibration Damping
Active and Passive Vibration Damping

Author: Amr M. Baz

Publisher: John Wiley & Sons

Published: 2019-04-08

Total Pages: 751

ISBN-13: 1118481925

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A guide to the application of viscoelastic damping materials to control vibration and noise of structures, machinery, and vehicles Active and Passive Vibration Damping is a practical guide to the application of passive as well as actively treated viscoelastic damping materials to control vibration and noise of structures, machinery and vehicles. The author — a noted expert on the topic — presents the basic principles and reviews the potential applications of passive and active vibration damping technologies. The text presents a combination of the associated physical fundamentals, governing theories and the optimal design strategies of various configurations of vibration damping treatments. The text presents the basics of various damping effective treatments such as constrained layers, shunted piezoelectric treatments, electromagnetic and shape memory fibers. Classical and new models are included as well as aspects of viscoelastic materials models that are analyzed from the experimental characterization of the material coefficients as well as their modeling. The use of smart materials to augment the vibration damping of passive treatments is pursued in depth throughout the book. This vital guide: Contains numerical examples that reinforce the understanding of the theories presented Offers an authoritative text from an internationally recognized authority and pioneer on the subject Presents, in one volume, comprehensive coverage of the topic that is not available elsewhere Presents a mix of the associated physical fundamentals, governing theories and optimal design strategies of various configurations of vibration damping treatments Written for researchers in vibration damping and research, engineers in structural dynamics and practicing engineers, Active and Passive Vibration Damping offers a hands-on resource for applying passive as well as actively treated viscoelastic damping materials to control vibration and noise of structures, machinery and vehicles.

Exact Analysis Of Bi-periodic Structures
Exact Analysis Of Bi-periodic Structures

Author: C W Cai

Publisher: World Scientific

Published: 2002-03-25

Total Pages: 280

ISBN-13: 9814488747

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By using the U-transformation method, it is possible to uncouple linear simultaneous equations, either algebraic or differential, with cyclic periodicity. This book presents a procedure for applying the U-transformation technique twice to uncouple the two sets of unknown variables in a doubly periodic structure to achieve an analytical exact solution.Explicit exact solutions for the static and dynamic analyses for certain engineering structures with doubly periodic properties — such as a continuous truss with any number of spans, cable network and grillwork on supports with periodicity, and grillwork with periodic stiffening members or equidistant line supports — can be found in the book. The availability of these exact solutions not only helps with the checking of the convergence and accuracy of numerical solutions, but also provides a basis for optimization design for these types of structures.The study of the force vibration and mode shape of periodic systems with nonlinear disorder is yet another research area which has attained considerable success by the U-transformation method. This book illustrates the analytical approach and procedure for the problems of localization of the mode shape of nearly periodic systems together with the results.

Vibrations of Rotationally Periodic Structures
Vibrations of Rotationally Periodic Structures

Author: Andres M. Rodriguez

Publisher:

Published: 2022

Total Pages: 0

ISBN-13:

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Blisk components are an integral part of jet engines and power generation systems. Composed of a single monolithic structure, integral blisks combine the blade-and-disk portion of primary components such as the fan, compressor stage, or turbine stage. This design modification increases the aerodynamic performance while decreasing the cost and eliminating time of assembly. However, these benefits come with the loss of blade-disk connection interfaces, which greatly reduces the structure’s damping and its ability to attenuate unwanted structural vibrations. Blisk dynamics are impacted by mistuning, which is a disruption of the periodic symmetry of otherwise identical bladed sections. This disruption degrades the overall performance of components. This dissertation advances theoretical and experimental studies into mistuning, both in terms of characterization and vibration localization. A theoretical analysis of wave propagation in periodic structures shows that vibration localization arises from two separate generating mechanisms: an isolated defect or random variations throughout the structure. Through two novel metrics--the band flatness factor and the localization amplification criterion--we establish a unique approach to identifying localized modes on cyclic structures. We present a novel framework that distinguishes between the response of the tuned and mistuned system. A characteristic single-degree-of-freedom response of the tuned system to engine-order forcing forms the basis of our mistuning characterization framework. The actual mistuning (or tuned system) characterization is performed through computations of a modified modal assurance criterion, termed here the modal mistuning criterion. The modal mistuning criterion uses frequency response function data obtained from engine order-forcing profiles and tuned system modes derived from a model to compute the modal contribution to a mistuned response. Finally, this mistuning characterization metric is validated through experimental tests on multiple academic blisk components.

Vibration of Nearly Periodic Structures and Mistuned Bladed Rotors
Vibration of Nearly Periodic Structures and Mistuned Bladed Rotors

Author: Alok Sinha

Publisher: Cambridge University Press

Published: 2017-06-16

Total Pages: 201

ISBN-13: 1108101348

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This is the first comprehensive volume on nearly periodic structures and mistuned blade vibration. Alok Sinha presents fundamental concepts and state-of-the-art techniques in the analysis of free and forced response of a nearly periodic structure, weaving together his own work (covering thirty-five years of research in this field) with works by other researchers. He also discusses similarities between tools used in bladed rotor analysis and condensed matter physics. Specific subjects covered include the reasons behind mode localization, the reasons behind amplitude amplification of steady-state response, state-of-the-art computational techniques for mistuned bladed rotors including multistage rotors, identification of mistuning from measured response, vibration localization in linear atomic chains, and analysis of two-dimensional periodic structures.