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Passive and Active Structural Vibration Control in Civil Engineering PDF

380 Pages·1994·50.452 MB·English
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CISM COURSES AND LECTURES Series Editors: The Rectors of CISM Sandor Kaliszky- Budapest Mahir Sayir -Zurich Wilhelm Schneider-Wien The Secretary General of CISM Giovanni Bianchi -Milan Executive Editor Carlo Tasso -Udine The series presents lecture notes, monographs, edited works and proceedings in the field of Mechanics, Engineering, Computer Science and Applied Mathematics. Purpose of the series in to make known in the international scientific and technical community results obtained in some of the activities organized by CISM, the International Centre for Mechanical Sciences. INTERNATIONAL CENTRE FOR MECHANICAL SCIENCES COURSES AND LECfURES -No. 345 PASSIVE AND ACTIVE STRUCTURAL VIBRATION CONTROL IN CIVIL ENGINEERING EDITED BY T.T. SOONG AND M.C. COSTANTINOU STATE UNIVERSITY OF NEW YORK AT BUFFALO Springer-Verlag Wien GmbH Le spese di stampa di questo volume sono in parte coperte da contributi del Consiglio Nazionale delle Ricerche. This volume contains 202 illustrations This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned specifically those of translation, reprinting, re-use of illustrations, broadcasting, reproduction by photocopying machine or similar means, and storage in data banks. © 1994 by Springer-Verlag Wien Originally published by CISM, Udine in 1994. In order to make this volume available as economically and as rapidly as possible the authors' typescripts have been reprodu::ed in their original forms. This method unfortunately has its typographical limitations but it is hoped that they in no way distract the reader. ISBN 978-3-211-82615-7 ISBN 978-3-7091-3012-4 (eBook) DOI 10.1007/978-3-7091-3012-4 PREFACE In structural engineering, one of the constant challenges is to find new and better means of designing new structures or strengthening existing ones so that they, together with their occupants and contents, can be better protected from the damaging effects of destructive environmental forces such as wind, wave loads, and earthquakes. As a result, new and innovative concepts of structural protection have been advanced and are at various stages of development. Structural protective systems can be divided into three groups as shown in Table I. The technique of seismic isolation is now widely used in many parts of the world. A seismic isolation system is typically placed at the foundation of a structure which, by means of its flexibility and energy absorption capability, partially absorbs and partially reflects some of the earthquake input energy before it is transmitted to the structure. The net effect is a reduction of energy dissipation demand on the structural system, resulting in an increase in its survivability. Table I. Structural Protective Systems Seismic Passive Energy Active Isolation Dissipation Control Elastomeric Bearings Metal!ic Dampers Active Bracing Systems Lead Rubber Bearings Friction Dampers Active Mass Dampers Elastomeric Bearings with Viscoelastic Dampers Active Variable Energy Dissipating Devices Stiffness or Damping Systems Viscous Dampers Sliding Friction Pendulum Pulse Systems Tuned Mass Dampers Flat Sliding Bearings with Aerodynamic Appendages Restoring Force Devices Tuned Liquid Dampers Lubricated Sliding Bearings with Energy Dissipating Devices Much progress has also been made in research and development of passive energy dissipation devices for structural applications. Similar to seismic isolation technology, the basic role of passive energy dissipation devices when incorporated into a structure is to absorb or consume a portion of the input energy, thereby reducing energy dissipation demand on primary structural members and minimizing possible structural damage. Unlike seismic isolation, however, these devices can be effective against wind excited motions as well as those due to earthquakes. In recent years, serious efforts have been undertaken to develop the concept of energy dissipation or supplemental damping into a workable technology, and a number of these devices have been installed in structures throughout the world. Active control research has a more recent origin. Active structural control is an area of structural protection in which the motion of a structure is controlled or modified by means of the action of a control system through some external energy supply. Considerable attention has been paid to active structural control research in recent years. It is now at the stage where actual systems have been designed,fabricated and installed in full-scale structures. This collection of lecture notes represents an attempt to introduce the basic concepts of these relatively new technologies, to provide a working knowledge of this exciting and fast expanding field, and to bring up-to-date current research and world-wide development in seismic isolation, passive energy dissipation, and active control. The book is divided into three parts, each addressing one of these topics. In each case, basic principles are introduced, followed by design and applications, implementation issues, case studies, and code issues if applicable. It is a great pleasure to acknowledge the significant contributions made to this lecture series by Professor Peter Hagedorn of the Technische Hoshschule Darmstadt, Germany; Professor Hirokazu lemura of Kyoto University, Japan,• and Professor Jose Rodellar of the Universidad Politecnica de Catalunya, Spain. They delivered excellent lectures at Udine in June, 1993, and contributed important chapters in this book, making this project a truly international ef!on. T.T. Soong M.C. Constantinou CONTENTS Page Preface Chapter I -Mechanical Vibrations and Vibration Control by P. Hagedorn ........................................................................................ 1 Chapter II -Seismic Isolation Systems: Introduction and Overwiew by M.C. Constantinou ............................................................................... 81 Chapter III -Properties of Sliding Bearings: Theory and Experiments by M.C. Constantinou ............................................................................... 97 Chapter IV -Design and Applications of Sliding Bearings by M.C. Constantinou ............................................................................. 111 Chapter V- Hybrid Earthquake Loading Tests of Various Types of Base Isolation Bearings byH.Iemura ........................................................................................ 137 Chapter VI -Earthquake Energy Partitioning in Bridge Structures with Seismic Isolators by H. I emura ........................................................................................ 16 1 Chapter VII -Seismic Isolation Development in U.S.: Case Studies by M.C. Constantinou ............................................................................. 169 Chapter VIII - Base Isolation Development in Japan -Code Provisions and Implementation - by H.lemura ........................................................................................ 187 Chapter IX -Seismic Isolation Development in Europe by M.C. Constantinou ............................................................................. 199 Chapter X- Principles of Friction, Viscoelastic, Yielding Steel and Fluid Viscous Dampers: Properties and Design by M.C. Constantinou ............................................................................. 209 Chapter XI -Principles of TMD and TLD- Basic Principles and Design Procedure- by H. lemura ........................................................................................ 241 Chapter XII- Passive Energy Disspiation Development in U.S. by M.C. Constantinou ............................................................................. 255 Chapter XIII- Introduction to Active Control by T.T. Soong ....................................................................................... 2 71 Chapter XIV -Active Control Concepts and Strategies by J. Rodellar ........................................................................................ 27 5 Chapter XV -Active Control Experiments and Structural Testing by T.T. Soong ...................................................................................... 3 1 9 Chapter XVI- Active Control Development in the U.S. and Case Studies by T.T. Soong ...................................................................................... 345 Chapter XVII -Active and Hybrid Control Development in Japan -Experiments and Implementation - by H. Iemura ........................................................................................ 355 Chapter XVIII -Summary and Concluding Remarks by T.T. Soong ...................................................................................... 3 7 3 CHAPTER I MECHANICAL VIBRATIONS AND VIBRATION CONTROL P. Hagedorn Technical University of Darmstadt, Darmstadt, Germany Abstract In these lectures, an introduction is given into the basic concepts of the theory of active and passive vibration damping. First one degree of freedom systems are discussed with respect to the different solution techniques and with view to damping and isolation mechanisms. Next the theory of optimal control is briefly introduced and some examples are given. Mechanical systems with n degrees of freedom are discussed and the concepts of mechanical impedance, vibration absorption anrl impedance matching are studied. The sources of nonli nearities in structural vibrations are examined and an appropriate solution technique is explored. Finally, special attention is devoted to a particular technical application, namely to the wind-exited vibrations of transmission lines, where the problem of the damping of bundles of conductors is discussed in more detail. 1 General Remarks on Damping, Systems with One Degree of Freedom 1.1 Introduction: Systems with One Degree of Freedom In what follows we shall briefly review the forced oscillations of a one-degree of freedom system described by mx+d±+cx=f(t) (1.1) where f(t) is a given forcing function. The coefficients m, d, and c respectively stand for mass, damping, and stiffness. 2 P. Hagedorn It is often convenient to introduce the parameters w := yCTm, T = wt. Indicating the derivatives with respect to the new dimensionless time T by a prime equation (1.1) can be reduced to (T) x 11 (r)+2DxI (r)+x(r)= m1 f z; , (1.2) where D=-d- ( 1.3) 2..jCm is the non-dimensional damping parameter which in most structures assumes values between 0.001 and 0.02. 1.2 Forced Oscillations 1.2.1 Response to Harmonic Excitation, Isolation The case of harmonic force excitation f(t) = j cos(fU + o:) (1.4) or in complex notation f(t) = Rel_(t) (1.5) with ( 1.6) is the most elementary one. In our notation we use-to indicate "amplitude" and underline complex quantities. The character j is used to denote the imaginary unit. The general solution to (1.1) is of the type x(t) = XH(t) + xp(t). (1.7) In many applications we are interested mainly in xp(t), that is in the particular solution of the inhomogenous equation. In the case of forced harmonic oscillations the Ansatz = _x p (t) _i; p eif'lt ( 1.8) leads to ( 1.9)

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