Proceedings of the NATO Advanced Research Workshop on Mechanical Vibrations and Audible Noise in Alternating Current Machines, Leuven, Belgium, August 4-8, 1986

Sensors, Instrumentation and Special Topics, Volume 6. Proceedings of the 29th IMAC, A Conference and Exposition on Structural Dynamics, 2011, the sixth volume of six from the Conference, brings together 27 contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied aspects of Structural Dynamics, including papers on Structural Health Monitoring, High Intensity Noise Generation and other Special Topics.

A unified approach is proposed for applied mechanics and optimal control theory. The Hamilton system methodology in analytical mechanics is used for eigenvalue problems, vibration theory, gyroscopic systems, structural mechanics, wave-guide, LQ control, Kalman filter, robust control etc. All aspects are described in the same unified methodology. Numerical methods for all these problems are provided and given in meta-language, which can be implemented easily on the computer. Precise integration methods both for initial value problems and for two-point boundary value problems are proposed, which result in the numerical solutions of computer precision. Key Features of the text include: -Unified approach based on Hamilton duality system theory and symplectic mathematics. -Gyroscopic system vibration, eigenvalue problems. -Canonical transformation applied to non-linear systems. -Pseudo-excitation method for structural random vibrations. -Precise integration of two-point boundary value problems. -Wave propagation along wave-guides, scattering. -Precise solution of Riccati differential equations. -Kalman filtering. -HINFINITY theory of control and filter.

Modal Analysis Topics Volume 3. Proceedings of the 29th IMAC, A Conference and Exposition on Structural Dynamics, 2011, the third volume of six from the Conference, brings together over 30 contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied aspects of Structural Dynamics.

This book studies methods for a robust design of rotors against self-excited vibrations. The occurrence of self-excited vibrations in engineering applications if often unwanted and in many cases difficult to model. Thinking of complex systems such as machines with many components and mechanical contacts, it is important to have guidelines for design so that the functionality is robust against small imperfections. This book discusses the question on how to design a structure such that unwanted self-excited vibrations do not occur. It shows theoretically and practically that the old design rule to avoid multiple eigenvalues points toward the right direction and have optimized structures accordingly. This extends results for the well-known flutter problem in which equations of motion with constant coefficients occur to the case of a linear conservative system with arbitrary time periodic perturbations.

Objectives This book is used to teach vibratory mechanics to undergraduate engineers at the Swiss Federal Institute of Technology of Lausanne. It is a basic course, at the level of the first university degree, necessary for the proper comprehension of the following disciplines. Vibrations of continuous linear systems (beams, plates) random vibration of linear systems vibrations of non-linear systems dynamics of structures experimental methods, rheological models, etc. Effective teaching methods have been given the highest priority. Thus the book covers basic theories of vibratory mechanics in an ap propriately rigorous and complete way, and is illustrated by nume rous applied examples. In addition to university students, it is suitable for industrial engineers who want to strengthen or complete their training. It has been written so that someone working alone should find it easy to read. pescription The subject of the book is the vibrations of linear mechanical sys tems having only a finite number of degrees of freedom (ie discrete linear systems). These can be divided into the following two catego ries: -X- systems of solids which are considered to be rigid, and which are acted upon by elastic forces and by linear resist.ive forces (viscous damping forces). deformable continuous systems which have been made discrete. In other words, systems which are replaced (approximately) by systems having only a limited number of degrees of freedom, using digital or experimental methods."

Controlling Chaos achieves three goals: the suppression, synchronisation and generation of chaos, each of which is the focus of a separate part of the book. The text deals with the well-known Lorenz, Roessler and Henon attractors and the Chua circuit and with less celebrated novel systems. Modelling of chaos is accomplished using difference equations and ordinary and time-delayed differential equations. The methods directed at controlling chaos benefit from the influence of advanced nonlinear control theory: inverse optimal control is used for stabilization; exact linearization for synchronization; and impulsive control for chaotification. Notably, a fusion of chaos and fuzzy systems theories is employed. Time-delayed systems are also studied. The results presented are general for a broad class of chaotic systems. This monograph is self-contained with introductory material providing a review of the history of chaos control and the necessary mathematical preliminaries for working with dynamical systems.

A new approach to the theory of mechanisms and machines, based on a lecture course for mechanical engineering students at the St. Petersburg State Technical University. The material differs from traditional textbooks due to its more profound elaboration of the methods of structural, geometric, kinematic and dynamic analysis. These established and novel methods take into account the needs of modern machine design as well as the potential of computers.

A material continuum moving axially at high speed can be met in numerous different technical applications. These comprise band saws, web papers during manufacturing, processing and printing processes, textile bands during manufacturing and processing, pipes transporting fluids, transmission belts as well as flat objects moving at high speeds in space. In all these so varied technical applications, the maximum transport speed or the transportation speed is aimed at in order to increase efficiency and optimize investment and performance costs of sometimes very expensive and complex machines and installations. The dynamic behavior of axially moving systems very often hinders from reaching these aims.

The book is devoted to dynamics of axially moving material objects of low flexural stiffness that are referred to as webs. Webs are moving at high speed, for example, in paper production the paper webs are transported with longitudinal speeds of up to 3000 m/min. Above the critical speed one can expect various dynamical instabilities mainly of divergent and flutter type.

The up-to-date state of investigations conducted in the field of the axially moving system dynamics is presented in the beginning of the book. Special attention is paid on nonlinear dynamic investigations of translating systems. In the next chapters various mathematical models that can be employed in dynamic investigations of such objects and the results of analysis of the dynamic behavior of the axially moving orthotropic material web are presented. To make tracing the dynamic considerations easier, a paper web is the main object of investigations in the book.

In recent years, mathematical modelling allied to computer simulation has emerged as en effective and invaluable design tool for industry and a discipline in its own right. This has been reflected in the popularity of the growing number of courses and conferences devoted to the area. The North East Polytechnics Mathematical Modelling and Computer Simulation Group has a balanced representation of academics and industrialists and, as a Group, has the objective of promoting a continuing partnership between the Polytechnics in the North East and local industry. Prior to the present conference the Group has organised eight conferences with a variety of themes related to mathematical modelling and computer simulation. The theme chosen for the Polymodel 9 Conference held in Newcastle upon Tyne in May 1986 was Industrial Vibration Modelling, which is particularly approp riate for 'Industry Year' and is an area which continues to present industry and academics with new and challenging problems. The aim of the Conference was to calIon and use the modelling experience of eminent academics and industrialists who are deeply involved in the solution of vibration problems. To this end the following four sessions were organised: (1) Vehicular Vibrations led by keynote speaker Dr S King (Westland Helicopters Ltd) (2) Acoustics led by Dr M Petyt (Southampton University) (3) Fluid/Structural Vibrations led by G T Willshare (British Maritime Technology) (4) Special Problems and Developing Areas to include nonlinearities, ultrasonics, transients, elastic stability, etc.

An impulse for writing this book has originated from the effort to sum marize and publicise the acquired results of a research team at the De partment of Automation of the Faculty of Electrical Engineering and In formatics, Slovak Technical University in Bratislava. The research team has been involved for a long time with control problems for machine production mechanisms and, in recent (approximately 15) years, its effort was aimed mostly at the control of electrical servosystems of robots. Within this scope, the members of the authors' staff solved the State Re search Task Ultrasonic sensing of the position of a robot hand, which was coordinated by the Institute of Technical Cybernetics of the Slovak Academy of Sciences in Bratislava. The problem was solved in a complex way, i.e. from a conceptual de sign of the measurement, through the measurement and evaluation sys tem, up to connection to the control system of a robot. Compensation of the atmospheric influence on the precision of measurement, as well as on the electroacoustical transducers, were important parts of the solution. The solution was aimed at using the ultrasonic pulse method which en ables the measurement of absolute 3D position coordinates, contrary to the relative position measurements by the incremental pick-ups which are standard robotic equipment."

The International Union of Theoretical and Applied Mechanics (IUTAM) initiated and sponsored an International Symposium on Optimization of Mechanical Systems held in 1995 in Stuttgart, Germany. The Symposium was intended to bring together scientists working in different fields of optimization to exchange ideas and to discuss new trends with special emphasis on multi body systems. A Scientific Committee was appointed by the Bureau of IUTAM with the following members: S. Arimoto (Japan) EL. Chernousko (Russia) M. Geradin (Belgium) E.J. Haug (U.S.A.) C.A.M. Soares (Portugal) N. Olhoff (Denmark) W.O. Schiehlen (Germany, Chairman) K. Schittkowski (Germany) R.S. Sharp (U.K.) W. Stadler (U.S.A.) H.-B. Zhao (China) This committee selected the participants to be invited and the papers to be presented at the Symposium. As a result of this procedure, 90 active scientific participants from 20 countries followed the invitation, and 49 papers were presented in lecture and poster sessions.

I wish to express my full indebtedness to all researchers in the field. Without their outstanding contribution to knowledge, this book would not have been written. The author wishes to express his sincere thanks and gratitude to Professors M. F. Ashby (University of Cambridge), N. D. Cristescu (University ofFlorida), N. Davids (The Pennsylvania State University), H. F. Frost (Dartmouth College), A W. Hendry (University of Edinburgh), F. A Leckie (University of California, Santa Barbara), A K. Mukherjee (University of California, Davis), T. Nojima (Kyoto University), J. T. Pindera (University of Waterloo), J. W. Provan (University of Victoria), K. Tanaka (Kyoto University), Y Tomita (Kobe University) and G. A Webster (Imperial College), and to Dr. H. J. Sutherland (Sandia National Laboratories). Permission granted to the author for the reproduction of figures and/or data by the following scientific societies, publishers and journals is gratefully acknowledged: ASME International, ASTM, Academic Press, Inc. , Addison Wesley Longman (Pearson Education), American Chemical Society, American Institute of Physics, Archives of Mechanics I Engineering Transactions (archiwum mechaniki stosawanej I rozprawy inzynierskie, Warsaw, Poland), British Textile Technology Group, Butterworth-Heinemann Ltd. (USA), Chapman & Hall Ltd. (International Thomson Publishing Services Ltd. ), Elsevier Science-NL (The Netherlands), Elsevier Science Limited (U. K. ), Elsevier SequoiaS. A (Switzerland), John Wiley & Sons, Inc. , lOP Publishing Limited (UK), Kluwer Academic Publishers (The Netherlands), Les Editions de Physique Les Ulis (France), Pergamon Press Ltd. (U. S. A), Society for Experimental Mechanics, Inc.

The contributions to this book cover a wide range of applications of Soft Computing to the chemical domain. The early roots of Soft Computing can be traced back to Lotfi Zadeh's work on soft data analysis [1] published in 1981. 'Soft Computing' itself became fully established about 10 years later, when the Berkeley Initiative in Soft Computing (SISC), an industrial liaison program, was put in place at the University of California - Berkeley. Soft Computing applications are characterized by their ability to: * approximate many different kinds of real-world systems; * tolerate imprecision, partial truth, and uncertainty; and * learn from their environment. Such characteristics commonly lead to a better ability to match reality than other approaches can provide, generating solutions of low cost, high robustness, and tractability. Zadeh has argued that soft computing provides a solid foundation for the conception, design, and application of intelligent systems employing its methodologies symbiotically rather than in isolation. There exists an implicit commitment to take advantage of the fusion of the various methodologies, since such a fusion can lead to combinations that may provide performance well beyond that offered by any single technique.

The papers in this volume address advanced nonlinear topics in the general areas of vibration mitigation and system identification, such as, methods of analysis of strongly nonlinear dyanmical systems; techniques and methodologies for interpreting complex, multi-frequency transitions in damped nonlinear responses; new approaches for passive vibration mitigation based on nonlinear targeted energy transfer (TET) and the associated concept of nonlinear energy sink (NES); and an overview and assessment of current nonlinear system identification techniques.

This book is a collection of papers contributed by some of the greatest names in the areas of chaos and nonlinear dynamics. Each paper examines a research topic at the frontier of the area of dynamical systems. As well as reviewing recent results, each paper also discusses the future perspectives of each topic. The result is an invaluable snapshot of the state of the ?eld by some of the most important researchers in the area. The ?rst contribution in this book (the section entitled "How did you get into Chaos?") is actually not a paper, but a collection of personal accounts by a number of participants of the conference held in Aberdeen in September 2007 to honour Celso Grebogi's 60th birthday. At the instigation of James Yorke, many of the most well-known scientists in the area agreed to share their tales on how they got involved in chaos during a celebratory dinner in Celso's honour during the conference. This was recorded in video, we felt that these accounts were a valuable historic document for the ?eld. So we decided to transcribe it and include it here as the ?rst section of the book.

Time series with mixed spectra are characterized by hidden periodic components buried in random noise. Despite strong interest in the statistical and signal processing communities, no book offers a comprehensive and up-to-date treatment of the subject. Filling this void, Time Series with Mixed Spectra focuses on the methods and theory for the statistical analysis of time series with mixed spectra. It presents detailed theoretical and empirical analyses of important methods and algorithms. Using both simulated and real-world data to illustrate the analyses, the book discusses periodogram analysis, autoregression, maximum likelihood, and covariance analysis. It considers real- and complex-valued time series, with and without the Gaussian assumption. The author also includes the most recent results on the Laplace and quantile periodograms as extensions of the traditional periodogram. Complete in breadth and depth, this book explains how to perform the spectral analysis of time series data to detect and estimate the hidden periodicities represented by the sinusoidal functions. The book not only extends results from the existing literature but also contains original material, including the asymptotic theory for closely spaced frequencies and the proof of asymptotic normality of the nonlinear least-absolute-deviations frequency estimator.

Modal analysis is a discipline that has developed considerably during the last 30 years. Theoretical and Experimental Modal Analysis is a new book on modal analysis aimed at a wide range of readers, from academics such as post-graduate students and researchers, to engineers in many industries who use modal analysis tools and need to improve their knowledge of the subject. Divided into eight chapters, the book ranges from the basics of vibration theory and signal processing to more advanced topics, including identification techniques, substructural coupling, structural modification, updating of finite element models and nonlinear modal analysis. There is also an entire chapter dedicated to vibration testing techniques. It has been written with a diversity of potential readers in mind, so that all will be able to follow the book easily and assimilate the concepts involved.

This volume contains summaries of lectures and contributed papers delivered at an International Summer School on "Dynamical Phenomena at Surfaces, I nterfaces and Superl atti ces" hel d at the Ettore Maj orana Centre for Sci en- tific Culture, Erice (Sicily), Italy, July 1-13, 1984. The School was orga- ni zed under the auspi ces of the Surfaces and Interfaces Secti on of the Condensed Matter Division of the European Physical Society as the sixth course in the series on Materials Science and Technology. Approximately 60 parti c i pants from all regi ons of Europe, the Uni ted States, and further afield - Hong Kong, China, India - were able to take part in a program of 45 lectures and 11 contributed talks, which covered most of the solid-state aspects of the subject. In recent years, there has been an explosion of interest in the proper- ties of carefully prepared surfaces, interfaces, and multilayer thin films. This advance in research has received its impetus from the technological re- levance of surfaces and interfacial phenomena associated with heterogeneous catalysis, corrosion, and, particularly, new developments in microelectronics. One of the most important developments to emerge over the past decade has been our ability to prepare ultra-thin structures at the submicron level, i. e. , to engineer low-dimensional solids at the atomic-scale level.

The numerous applications of optimal control theory have given an incentive to the development of approximate techniques aimed at the construction of control laws and the optimization of dynamical systems. These constructive approaches rely on small parameter methods (averaging, regular and singular perturbations), which are well-known and have been proven to be efficient in nonlinear mechanics and optimal control theory (maximum principle, variational calculus and dynamic programming). An essential feature of the procedures for solving optimal control problems consists in the necessity for dealing with two-point boundary-value problems for nonlinear and, as a rule, nonsmooth multi-dimensional sets of differential equations. This circumstance complicates direct applications of the above-mentioned perturbation methods which have been developed mostly for investigating initial-value (Cauchy) problems. There is now a need for a systematic presentation of constructive analytical per turbation methods relevant to optimal control problems for nonlinear systems. The purpose of this book is to meet this need in the English language scientific literature and to present consistently small parameter techniques relating to the constructive investigation of some classes of optimal control problems which often arise in prac tice. This book is based on a revised and modified version of the monograph: L. D. Akulenko "Asymptotic methods in optimal control." Moscow: Nauka, 366 p. (in Russian)."

Problems involving synthesis of mathematical models of various physical systems, making use of these models in practice and verifying them qualitatively has - come an especially important area of research since more and more physical - periments are being replaced by computer simulations. Such simulations should make it possible to carry out a comprehensive analysis of the various properties of the system being modelled. Most importantly its dynamic properties can be - dressed in a situation where this would be difficult or even impossible to achieve through a direct physical experiment. To carry out a simulation of a real, phy- cally existing system it is necessary to have its mathematical description; the s- tem being described mathematically by equations, which include certain variables, their derivatives and integrals. If a single independent variable is sufficient in - der to describe the system, then derivatives and integrals with respect to only that variable will appear in the equations. Differentiation of the equation allows the integrals to be eliminated and produces an equation which includes derivatives with respect to only one independent variable i. e. an ordinary differential equation. In practice, most physical systems can be described with sufficient accuracy by linear differential equations with time invariant coefficients. Chapter 2 is devoted to the description of models by such equations, with time as the independent va- able.

Most practical processes such as chemical reactor, industrial furnace, heat exchanger, etc., are nonlinear stochastic systems, which makes their con trol in general a hard problem. Currently, there is no successful design method for this class of systems in the literature. One common alterna tive consists of linearizing the nonlinear dynamical stochastic system in the neighborhood of an operating point and then using the techniques for linear systems to design the controller. The resulting model is in general an approximation of the real behavior of a dynamical system. The inclusion of the uncertainties in the model is therefore necessary and will certainly improve the performance of the dynamical system we want to control. The control of uncertain systems has attracted a lot of researchers from the control community. This topic has in fact dominated the research effort of the control community during the last two decades, and many contributions have been reported in the literature. Some practical dynamical systems have time delay in their dynamics, which makes their control a complicated task even in the deterministic case. Recently, the class ofuncertain dynamical deterministic systems with time delay has attracted some researchers, and some interesting results have been reported in both deterministic and stochastic cases. But wecan't claim that the control problem ofthis class ofsystems is completely solved; more work must be done for this class of systems.

Random Vibration in Spacecraft Structures Design is based on the lecture notes "Spacecraft structures" and "Special topics concerning vibration in spacecraft structures" from courses given at Delft University of Technology. The monograph, which deals with low and high frequency mechanical, acoustic random vibrations is of interest to graduate students and engineers working in aerospace engineering, particularly in spacecraft and launch vehicle structures design.

This book presents the latest research results in the area of applied nonlinear dynamics and chaos theory. Papers by three academic generations address new applications of nonlinear dynamics to mechanics, including fluid-structure interaction, machining and mechanics of solids, and many other applications.

This volume covers the interdisciplinary field of disaster mitigatition against earthquakes with special emphasis on prevention of total collapse of existing low rise buildings towards reduction of life losses and economical assets. Rehabilitation of thousands of low-rise buildings in many big cities located in earthquake prone areas, is practically impossible even though there are experimentally and analytically approved intervention techniques to protect these existing buildings. It is simply not possible to find a proper way and proper amount of financial support to do this job. It will be more realistic to change the target to be achieved in a relatively short time, especially if time shortage starts to become the most critical issue. The new target can be specified as the prevention of total collapse of low-rise low-cost existing buildings, at least to save as much lives and property as possible. Simple prescriptive techniques, which can be implemented by the building owners, should be prepared. The cost of the improvement techniques, all kinds of legal, economical and social issues for convincing people, and promotions such as tax exemptions should be discussed in detail. Writers of all chapters are leading researchers and engineers working in the field of structural and earthquake engineering. The book will start with an introduction chapter written by Prof. Helmut Krawinkler of Stanford University. In this chapter, past and present of studies towards seismically safe design and construction will be introduced, as well as potential future trends in structural and earthquake engineering. In other chapters, different subjects will be presented under three main titles, namely; determination of seismic risks, seismic safety assessment of existing buildings, and measures for prevention of total collapse.