mr 댐퍼를 기반으로 하는 스마트 수동제어 시스템

MRMR 댐퍼를 기반으로 하는 댐퍼를 기반으로 하는 스마트 수동제어 시스템스마트 수동제어 시스템

대한토목학회 정기 학술대회 대한토목학회 정기 학술대회 20042004년 년 1010 월 월 2121 일일

조상원 : KAIST 건설환경공학과 , 박사이헌재 : KAIST 건설환경공학과 , 박사과정오주원 : 한남대학교 토목환경공학과 , 교수이인원 : KAIST 건설환경공학과 , 교수

조상원 : KAIST 건설환경공학과 , 박사이헌재 : KAIST 건설환경공학과 , 박사과정오주원 : 한남대학교 토목환경공학과 , 교수이인원 : KAIST 건설환경공학과 , 교수

2 2 Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea

CONTENTSCONTENTS

IntroductionIntroduction

Electromagnetic Induction System for Electromagnetic Induction System for MR DamperMR Damper

Numerical ExamplesNumerical Examples

ConclusionsConclusions

Further StudyFurther Study


BackgroundsBackgrounds

Introduction Introduction

• Semi-active control device has Semi-active control device has

reliability of passivereliability of passive and and adaptability of activeadaptability of active system. system.

• MR dampers are quite promising semi-active device forMR dampers are quite promising semi-active device for

small power requirementsmall power requirement, , reliabilityreliability, and , and inexpensiveinexpensive to to manufacture. manufacture.


Without Magnetic Fields With Magnetic Fields

Bearing &

Seal

CoilAccumulator

MR FluidDiaphragm

Wires to

Electromgnet

Characteristics of MR damperCharacteristics of MR damper


Installation of Conventional MR DamperInstallation of Conventional MR Damper

MR damper

• External power source, controller, sensorsExternal power source, controller, sensors

• Complicated network using many MR dampersComplicated network using many MR dampers

• Difficulties to set up and maintainDifficulties to set up and maintain


Objective and ScopeObjective and ScopeDevelopment of simple and effective control deviceDevelopment of simple and effective control device

• Consists of permanent magnets and solenoid Consists of permanent magnets and solenoid

• Changes kinetic energy of MR damper to electric energyChanges kinetic energy of MR damper to electric energy


Schematic diagram

Electromagnetic Induction (EMI) System

EMI system

Line for external power source

MR fluidSolenoid

MR fluid Solenoid Permanent magnet

Conventional MR Damper

MR Damper with EMI System


Mechanism

MR Damper

MR Damper

MR Damper

Permanent magnet

Solenoid

External power

Conventional MR Damper

MR Damper with EMI System


• Faraday’s law of induction

n : turns/m

B : magnetic flux

B : magnetic field

A : cross area

dt

dBAn

dt

dΦnε B (1)

Estimation of induced voltages by EMI system


• If we assume as below

- Magnetic field : 1.2 T (Tesla)

- Turns of solenoid : 900 turns/m

- Area of cross section : 13.2 (cm2)

- Velocity of stroke : 9 cm/s (max. value of uncontrolled)

• This EMI system will be applied to numerical example for examination of applicability

560

21001320900

.

..

dt

dBAn

Length : 5cm

Area : 13.2cm2

2.55(V)


MR Damper

Numerical Example Three-story building (Dyke et al. 1996)


,

3.9800

03.980

003.98

kgM s

m

NC s

sec

50500

5010050

050175

m

NK s

84.684.60

84.67.1384.6

084.60.12

System data


• Determination of coil turns for solenoid

• By varying two parameters, Sa and Si

Sa : summation of peak acceleration at each floor

Si : summation of peak interstory drift at each floor

which are normalized by uncontrolled responses

• Using envelope of maximum value of Sa and Si

for El Centro, Hachinohe, Kobe earthquakes

• Two EMI systems are designed:

EMI-A from Sa and EMI-D from Si

Design of EMI system


1 2 3 4 5 6 7 8 9 10

x 104

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

1 2 3 4 5 6 7 8 9 10

x 104

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

Variations of Sa Envelope of max. responses

Coil turns/m Coil turns/m

Sa

Hachinohe

Kobe

El Centro

1 2 3 4 5 6 7 8 9 10

x 104

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

1 2 3 4 5 6 7 8 9 10

x 104

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

Coil turns/m Coil turns/m

Si

Hachinohe

Kobe

El Centro

EMI-A : 2.6104

EMI-D : 2.2104

Max

. en

velo

pe o

f S

aM

ax. e

nve

lope

of

Si


• Comparisons– Proposed EMI systems : EMI-A, EMI-D– Previous clipped optimal controllers :

Clipped-A, Clipped-D

• Performances– Normalized acceleration and drift at each floor– El Centro, Hachinhe, Kobe, Northridge earthquakes

Analysis


• Induced voltages for various earthquakes by EMI system

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-1

-0.5

0

0.5

1

1.5

2

2.5

3

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-1

-0.5

0

0.5

1

1.5

2

2.5

3

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-1

-0.5

0

0.5

1

1.5

2

2.5

3

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-1

-0.5

0

0.5

1

1.5

2

2.5

3

Time (sec)

Vol

tage

(V

)V

olta

ge (

V)

Time (sec)

EL Centro

Kobe

Hachinohe

Northridge

ResultsAnalysis


• Normalized accelerations at each floor

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1 2 30

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1 2 3

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1 2 30

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1 2 3

EL Centro

Kobe

Hachinohe

Northridge

Floor level

Nor

mal

ized

acc

el.

Nor

mal

ized

acc

el.

Floor level

Clipped-DClipped-AEMI-DEMI-A


Nor

mal

ized

acc

el.

Nor

mal

ized

acc

el.

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1 2 30

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1 2 3

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1 2 30

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1 2 3

EL Centro

Kobe

Hachinohe

Northridge

Floor level Floor level

Clipped-DClipped-AEMI-DEMI-A

• Normalized interstory drifts at each floor


• Normalized peak responses for various earthquakes

0 0.5 1 0 0.5 1

El Centro

Hachinohe

Kobe

Northridge

Peak Accel. Peak Drift

Clipped-D

Clipped-A

EMI-D

EMI-A


EMI system

• Developed for MR damper-based control system

• Consists of permanent magnet and solenoid

• Simple structure without power, controller, sensors

• Shows comparable performances to clipped optimal controller

ConclusionsConclusions


• 특허등록 : 등록번호 0416398 • Experimental tests

• Numerical modeling of EMI system using neural network

Further StudyFurther Study

mr 댐퍼를 기반으로 하는 스마트 수동제어 시스템

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