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  • i

    공학석사학위논문

    Application of a multiple tuned mass damper

    for mitigating wind-induced vibration of a

    parallel-stayed bridge

    병렬사장교의 풍진동 저감을 위한 다중동조

    질량감쇠기의 적용

    2015년 2월

    서울대학교 대학원

    건설환경공학부

    Ouahidi Ayoub

  • ii

  • iii

  • iv

    ABSTRACT

    Vortex induced vibration (VIV) was observed in the second Jindo Bridge in

    South Korea, and a Multiple Tuned Mass Damper (MTMD) was designed and

    installed by a private design company to increase the mechanical damping and

    reduce the vibration.

    Due to overdesigning of the actual damping system, an alternative design of the

    MTMD is proposed. The design procedure was decided based on wind tunnel tests,

    field monitoring, and numerical simulation.

    The design theory of the TMD and MTMD was studied, and the design

    properties of the single TMD are used for the preliminary design of the MTMD.

    Design criteria were considered and MTMD design procedure was established based

    on the defined criteria.

    The procedure was applied to the second Jindo Bridge. Then an alternative

    design was proposed. Satisfying the design criteria and presenting good properties

    for mitigating the VIV, this procedure is sufficiently safe, based on the performed

    numerical simulation. Moreover, it is not overdesigned for the required performance.

    After understanding and applying the MTMD design procedure, the current

    MTMD performance is evaluated based on field monitoring and the general

    properties of the MTMD and VIV are verified.

  • v

    Keywords: Multiple tuned mass damper, Vortex induced vibration, cable-

    stayed bridge, field monitoring, mitigation,

    Student Number: 2013-23857

  • vi

    TABLE OF CONTENTS

    ABSTRACT ................................................................................................. IV

    TABLE OF CONTENTS ............................................................................. VI

    LIST OF FIGURES................................................................................... VIII

    LIST OF TABLES ....................................................................................... IX

    CHAPTER 1 INTRODUCTION ................................................................... 1

    1.1 RESEARCH CONTEXT AND PLAN ....................................................................... 1

    1.2 BACKGROUND RESEARCH ................................................................................ 3

    CHAPTER 2 RESEARCH CONTEXT ......................................................... 5

    2.1 STRUCTURAL DESIGN LABORATORY ................................................................ 5

    2.1.1 Research fields .......................................................................................... 5

    2.1.2 Experimental facility ................................................................................. 6

    2.1.3 Laboratory description............................................................................... 7

    2.1.4 Current research issues and motivations ................................................... 7

    2.2 INVESTIGATED BRIDGE: SECOND JINDO BRIDGE.............................................. 8

    2.3 CURRENT MTMD DESIGN AND PROBLEM DEFINITION ..................................... 9

    CHAPTER 3 THEORY OF THE MULTIPLE TUNED MASS DAMPER 13

    3.1 SINGLE TUNED MASS DAMPER........................................................................ 13

    3.1.1 Definition and function............................................................................ 13

    3.1.2 Characteristics: design of the TMD ......................................................... 13

    3.1.3 Theory of the TMD: Derivation .............................................................. 14

  • vii

    3.2 MULTIPLE TUNED MASS DAMPER ................................................................... 16

    3.2.1 Introduction ............................................................................................. 16

    3.2.2 Design of MTMD .................................................................................... 16

    CHAPTER 4 APPLICATION: DESIGN OF THE MTMD ......................... 21

    4.1 DESIGN CRITERIA ........................................................................................... 21

    4.2 PROCEDURE OVERVIEW .................................................................................. 22

    4.3 ALTERNATIVE DESIGN RESULTS ...................................................................... 24

    4.3.1 Determination of the mass ratio .............................................................. 24

    4.3.2 Calculating the optimal bandwidth .......................................................... 26

    4.3.3 Deciding on the TMDs damping ratio ..................................................... 26

    4.3.4 Checking the performance of the MTMD ............................................... 27

    4.3.5 Summary of the design of the MTMD .................................................... 29

    4.4 THE EFFECT OF THE BANDWIDTH ON MITIGATION .......................................... 30

    4.5 COMPARISON WITH THE CURRENT MTMD DESIGN........................................ 31

    CHAPTER 5 PERFORMANCE EVALUATION OF THE CURRENT

    MTMD ......................................................................................................... 33

    5.1 GENERAL DEVELOPMENT OF THE VIV ........................................................... 34

    5.2 ACCELERATION AND POWER SPECTRAL DENSITY .......................................... 35

    5.3 TMD RESPONSE: PHASE LAG BETWEEN THE MTMD AND THE BRIDGE ......... 37

    CHAPTER 6 CONCLUSIONS ................................................................... 40

    REFERENCES ............................................................................................. 42

    FRENCH EXTENDED ABSTRACT .......................................................... 44

  • viii

    LIST OF FIGURES

    FIGURE 1 WIND TUNNEL FACILITY............................................................................................. 7

    FIGURE 2 PARALLEL TWIN JINDO BRIDGE .................................................................................. 9

    FIGURE 3 DISPOSITION OF THE TWO BRIDGE DECKS .................................................................. 9

    FIGURE 4 CURRENT MTMD CONFIGURATION .......................................................................... 10

    FIGURE 5 BRIDGE FREQUENCY VARIATION FOR THE OBSERVED PERIOD ................................. 11

    FIGURE 6 EFFECT OF THE DAMPING RATIO ON THE DISPLACEMENT OF THE BRIDGE ................. 12

    FIGURE 7 MTMD FREQUENCY DISTRIBUTION MODEL ............................................................. 17

    FIGURE 8 FREE BODY DIAGRAM OF THE BRIDGE (LEFT), AND TMDS (RIGHT) .......................... 18

    FIGURE 9 DESIGN PROCEDURE OF THE MTMD ....................................................................... 23

    FIGURE 10 TOTAL EQUIVALENT DAMPING RATIO ..................................................................... 24

    FIGURE 11 DISPLACEMENT OF THE TMD (STROKE) ................................................................. 25

    FIGURE 12 EFFECT OF THE TMD DAMPING RATIO ON THE EQUIVALENT DAMPING ................... 27

    FIGURE 13 TIME HISTORY OF THE DISPLACEMENT OF THE CENTRAL TMD............................... 28

    FIGURE 14 ACCELERATION OF THE BRIDGE WITH AND WITHOUT TMD .................................... 29

    FIGURE 15 EFFECT OF THE FREQUENCY CHANGE ON THE RESPONSE FOR DIFFERENT MASS RATIO

    AND CURRENT DESIGN ...................................................................................................... 30

    FIGURE 16 FIELD MONITORING SETTING FOR THE SECOND JINDO BRIDGE ............................... 33

    FIGURE 17 DEVELOPMENT OF THE VIV FOR UNCONTROLLED