Table Of ContentCISM 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)
