new technology of structural seismic control with...

New Technology of Structural Seismic Control with Engineering Applications

Hong-Nan LigDalian University of Technology, China

Supported By NSFC and Ministry of Science and Technology

Outline• Challenges

E i i D• Engineering Damages• Energy dissipation Dampers

1 M t lli d1. Metallic damper2. Friction-Metallic Combination damper3. Story-increased buildings with energy dissipated3. Story increased buildings with energy dissipated

devices• Tuned Mass Damper • Tuned Liquid (Column) Damper• Base Isolation with Ruber Bearings• Active Mass Damper • Smart Vibration Control

C l i• Conclusions

ChallengesgA lot of high-rise buildings and large-span structures have been built or are under construction in China in recent years.y

National Stadium-- "Bird's Nest" National Grand Theater--"Egg shell"

New CCTV Building National Swimming Center--"Water Cube"Diwang Building

In Shenzhen

Jinmao Tower

In Shanghai

Oriental Peal TV Tower

In ShenzhenIn Shanghai

Sutong Bridge in Jiangsu

Engineering DamagesDam Damage Subway

DamageBrigde Damage

Damages under Earthquake

Transmission BuildingsStadium DamageTower

Damages during Winds

Challengesg

• These modern structures are flexible and will be subjectedThese modern structures are flexible and will be subjected to serious structural vibrations under earthquakes or wind excitations

• Significant efforts have been undertaken in structural control and great achievements have been made in China. g

• Structural control has been developed from theoretical analysis and experimental study into engineeringanalysis and experimental study into engineering application.

M t l t h i h b d i t t l• Many control techniques have been used in new structural design or existed buildings, bridges, facilities and other structuresstructures.

Energy dissipation Damper

1. Metallic dampersp


1. Metallic dampers “Double function” metallic damper

“Double function metallic dampers”



“D bl f ti t lli d ”“Double function metallic dampers”



“Double function metallic dampers” in office building of DUTDouble function metallic dampers in office building of DUT


1. Metallic dampers1. Metallic dampers

D bl f ti ild t lli dDouble function mild metallic dampers in the No. 3 Experiment Building of

DUT



Double function metallic dampers in Office Building of DUToub e u ct o eta c da pe s O ce u d g o U



“Double function metallic dampers” in office building of DUToub e u ct o eta c da pe s o ce bu d g o U


2. Friction-Metallic Combination damperp

Dissipative metallic plateFriction steel plate

Friction slote

Friction copper plate

A new type of metallic damper was presented. This damper dissipates input earthquake energy by not only its f i i b h i b l l i ldi ffriction behavior, but also steel yielding feature.

Experimental test

The Quasi static tests with this dampers wereThe Quasi-static tests with this dampers were performed in our State Key Laboratory to check its dissipation energy capability.dissipation energy capability.

Hysteretic curves

10

15P

F

-5

0

5

P(K

N)

x1 x3

f

x2

k

-40 -30 -20 -10 0 10 20 30 40

-15

-10

X(mm)

Tested curve Computational modelTested curve Computational model

Application in the actual building

6 Stor Teaching b ilding of Datian Middle School in Sich an Pro ince6-Story Teaching building of Datian Middle School in Sichuan Province

Application in the actual buildingNew types dampers

Structural parameter

FloorHeight

(m)Stiffness(109N/m)

Mass(kg)

1 4.2 0.375 3385700

2 3.6 0.325 2682300

3 3.6 0.29 2021600

4 3.6 0.265 1360800

5 3.6 0.243 708800

6 3.3 0.0374 47100

Application in the actual building

Dynamic analysis

Di l tDisplacement response

Metallic dampers

Dalian Mingxiu ValigeShear-Wall StructureShear-Wall Structure

FE Model

Metallic dampers

35 35

10

15

20

25

30

楼层编

号 no damper

with damper

10

15

20

25

30

楼层

编号

no damper

with

damper

Story Shift Reduction in x Story Shift Reduction in y

0

5

0 0.002 0.004 0.006 0.008 0.01

楼

层间位移角

with damper

0

5

0 0.002 0.004 0.006 0.008 0.01

楼

层间位移角

Story-Shift Reduction in x, Story-Shift Reduction in y

Energy dissipation

3. Story-increased buildings with energy dissipated devices

Energy dissipation


Friction damper device Construction photograph of friction damper devicefriction damper device

Energy dissipation


Reaction Beam

The repeated reversal loads are applied by a double-acted 30Ton Jack

hydraulic jack. The torture moment of tightened force of b lt id d ith

Specimen

Sensor

bolts are provided with different values: 10，20，30, 50 .

Steel FrameFixed Plate

mN 50 .

Installed Bolt

mN

T f i i d d iTest on friction damper device

Energy dissipation


Hysteretic Force (KN) Hysteretic Force (KN)

Displacement(mm)

t

(mm) Displacement(mm)

Figure 4 Hysteretic curves for damper device(Without the pieces, torture moment )mN 10

Figure 5 Hysteretic curves of damper device(Without the pieces, torture moment )mN 20

Hysteretic Force (KN) Hysteretic Force (KN)

Displacement(mm)

Displacement(mm)

Figure 4 Hysteretic curves for damper device(With the pieces torture moment )mN 10

( )

Figure 5 Hysteretic curves of damper device(With the pieces, torture moment )mN 20(With the pieces, torture moment )mN 10 ( p , )mN20

Mechanical Model

Comparisons between Theoretical and Test Results

Energy dissipation


Shaking table test resultsg

Energy dissipation

3. Story-increased buildings with energy dissipated devices3. Story increased buildings with energy dissipated devices

A four-story office building, built up in 1950's without the seismicdesign along Beiling Street in Shenyang because there was no anyseismic codes at that time in China is designed and analyzed with anseismic codes at that time in China, is designed and analyzed with anincreased four-story outer frame structure on its top by using thepassive control method presented. The existing building is composedof brick masonry structure; its design is not in compliance with thecurrent Seismic Code of China. The seismic protection intensity onthis building site is VII degrees, and the site soil belongs to the typeII in China Code.

Energy dissipation


The practical building story increased structure after constructionThe practical building story-increased structure after construction


3. Story-increased buildings with energy dissipated devicesFrame Column

New Outer FrameSliding-Friction Layer

Frame Floor

Damper

(a) Elevation

DamperExisting Building Roof

Damper

Figure 22 Construction of friction layer

The construction of friction layer and energy dissipated dampers (b) Cross Sectionand energy dissipated dampers (b) Cross Section

Tuned Mass Damper

Tuned Mass Damper

52m

TMD control system in a pedestrian bridgeTMD control system in a pedestrian bridge

Dalian GymnasiumCenter

Large suspended g ptruss

15.26m

36 8%1

控制前控制后

0.77 0.48736.8%

0度(

m/s

2 )

控制前控制后

1

加速

0 1 2 3 4 5-1

时间(s)

Tuned Liquid Damper

Tuned Liquid Damper, TLDq p ,

Water TankTank

Structure

Tuned Liquid Damper

We (1997) presented the multi-modal vibration control of ( ) pstructures using multiple TLDs.

The experimental results show h d i ff i fthat reduction effectiveness of

the seismic responses for controlling two modes is bettercontrolling two modes is better than controlling only a single mode

Tuned Liquid Column Damper

(1) Adjustable frequency tuned liquid column damper

b b

SpringSpring

k0 k0

ξ

k0

l

ks

x lx

cs

s

cs

ks

We (1998) presented a new adjustable frequency tuned liquid column damper by adding springs to the TLCD systemcolumn damper by adding springs to the TLCD system

Tuned Liquid Column Damper

(2) Circular Tuned Liquid Column Damperz质量中心

刚度中心(l1x l1y)

y

(l2x l2y)x

y

OA

hh

z H

exey x

y

O

R

x

oy

z

Orifice

CTLCD and an eccentric structure with liquid dampers q p

TLD-Application for Tall Buildings

Dalian Tall Buildingsg149.95 meters high, 46

stories，frame-shear wall structures Itswall structures. Its acceleration respone to wind load is 0.19 m/s2, which is larger than the code limit, 0.15 m/s2 。

TLDs are applied toTLDs are applied to reduce the structural response to satisfy the requirement of China Code.


There are 3 water tanks of 23 tons for fire protection and living, 2

水箱水箱

swiming pools with plane dimensions 5mx10m，

1.5 meter s deep. The first vibration period is 3 37 Th th i d

游泳池水箱游泳池

3.37s，Thus the periods of water tanks and swimming pools in the yTLD Pl A swimming pools in the y direction are tuned to the structural one

TLD Plane Arrangement

structural one.


TLD ParametersLenth.

AWidth

BDepth

hWater

WeightFrequencyω Numbe

rWater Tank

4m 4m 0.62m 9.872t 1.8639 rad/s 3

S 9 10 1 88 36 1 8 9 / 2Swimm-ing Pool

5.9m 10m 1.5m 88.36t 1.859 rad/s 2

The first modal mass of structrue is 13,939.05t and theratio of the water mass over it is as follows：

3 9.872 2 88.36 100% 1.48%13939 05

13939.05


Rates of Vbration Reduction on Top of Building

Acceleration displacement2MAX(m/ s2) Rates(%) Max(cm) Rates(%)

Without TLD 0.1888 — 3.97 —

Onl TLD 0 1817 3 76 3 77 5 04Only TLD 0.1817 3.76 3.77 5.04Tank+Pool

TLD 0.1462 22.56 3.00 24.43

Only water tanks are not OK;

Water tank + swimming pool are OK.


50 舒适度控制范围 50

35

40

45

无TLD 有TLD 35

40

45

无TLD 有TLD

20

25

30

楼层号

有

20

25

30

楼层

号

10

15

20

10

15

20

0.00 0.05 0.10 0.15 0.200

5

加速度(m/s2)

0 1 2 3 4 50

5

位移(cm)加速度(m/s)

Floor max acceleration

位移(cm)

Floor max displacement

Application with Tuned Liquid Damper

(1) The Dalian International Trade Center for Wind Reduction(2) Lucheng High-rise Apartment for Wind Comfortable Use(2) Lucheng High rise Apartment for Wind Comfortable Use

TLDTLD

TLD is proposed for wind-induced vibration control ofTLD is proposed for wind induced vibration control of Dalian International Trade Center

Base Isolation with Rubber Bearings


Design principle of base isolation and energy dissipation are included in the Code for Seismic Design of Buildings published by the agency of Ministry of Construction of China.

The design codes for base isolated highway bridges and base isolated railway bridges were also published by the agencies of Mi i f T i d Mi i f R il f ChiMinistry of Transportation and Ministry of Railway of China.

More than 2000 full-scale implementations of base isolated buildings and more bridges have been accomplished.

Isolators are mostly rubber bearings, only a few are sand y g ysliding layer or graphite layer in China.


Advantages of rubber bearing isolators:(1) Be safe in strong earthquake: reduce to 1/4-1/2 of the

response of traditional structures;(2) Save the building cost in many cases: 5-20 % of the

building cost can be saved;(3) B id f li ti d i l d i d(3) Be wide ranges of application: used in newly designed or

existed structures, important buildings and civil buildings or house buildings for protecting the structures or facilitiesor house buildings, for protecting the structures or facilities inside the buildings;

(4) Long working life: the safely working life of rubber(4) Long working life: the safely working life of rubber bearings are over 70 years which is very similar to the working life of structure itself.


Height-to-width ratio limit for isolated structures Height-to-width ratio limit for isolated structures

/ 1/ 2v ha a / 1/ 3v ha a


Suggested height-to-width ratio limits for isolated structuresgg g

S lid Si S f SiSite Type

Solid Site Medium Site Soft SitePeak Accel.

500~700 gal 4.5 1.5 1.0

300~500 gal 7.0 2.5 1.5

100~300 gal 10.0 4.0 2.5


Influenced Factors for Eccentric Structuresyz

o xStructural Parameters:

(1) Eccentric distances(1) Eccentric distances(2) Ratios of Torsional / translational frequencies

of superstructure (3) R i f T i l / l i l f i(3) Ratios of Torsional / translational frequencies

of isolated layerStructural Response Parametersp

(1) Amplitude factor of dynamic torque(2) Story relative displacements Xb, Xs(3) T l ti l l ti

vy

(3) Translational accelerations (4) Torsional acceleration(5) Story shear forces Vb、Vs M

o

ux

s

ex

ey


Si lifi d F l f T i l A l i Simplified Formula of Torsional Acceleration

]0015.0)05.0024.08.2([ 22

2b

bss

sss r

ere

x Solid Site:

Medium Site: ]33.0)42.222.0([ 22

2b

bss

sss r

ere

x

Soft Site: ]17.1)63.3421.1([ 22

2b

bss

sss r

ere

x

0e0e10e0/12.066.0

sb

s

或

且bsb eeeIn which:


Comparisons between Simplified and Time History Results

Lines with solid symbols are the numerical results of time history analysis.

Lines with hollow symbols are the results of simplified formula


Preliminary school building in Shenyang in China

Construction site

Smart Vibration Control

Magneto-Rheological (MR) dampersMagneto-Rheological (MR) dampers

Piezoelectric (PZT) friction damperPiezoelectric (PZT) friction damper

Shape memory alloy (SMA) based p y y ( )control

1. SMA concrete structures2. SMA dampers2. SMA dampers


MR dampers

MR fluids

MR damperMR damper


MR dampers 15001500

-500

0

500

1000

1500

阻尼

力(N

)

-500

0

500

1000

1500

阻尼

力(N

)

-0.010 -0.005 0.000 0.005 0.010

-1500

-1000

500

位移(m)-0.10 -0.05 0.00 0.05 0.10

-1500

-1000

500

速度(m/s)

1500 1500

0

500

1000

1500

阻尼

力/N

experiment Bingham sigmoid Double-sigmoid

0

500

1000

1500

阻尼力

/N

experiment Bingham sigmoid Double-sigmoid

-0.010 -0.005 0.000 0.005 0.010

-1500

-1000

-500

阻

位移/m-0.15 -0.10 -0.05 0.00 0.05 0.10 0.15

-1500

-1000

-500

阻

速度/(m.s-1)

Li (2006) proposed the following Double-Sigmoid model of MR dampers

xCeffxxk h

)(1 xC

eff bxxkyd h

)(1


MR dampers

加速速传感器加速速传感器

A/D转换器

MR阻尼器

电流控制器

由半主动控制策略

确定施加电流大小

D/A转换器

The shaking table test of an eccentric building with MR dampers

振动台

电流控制器


MR dampers 3 3

2

3

层

Uncontrolled Passive off Passive on MSC

2

3


层

2

3 Uncontrolled Passive off Passive on MSC

0 0 0 5 1 0 1 5 2 0 2 5 3 0 3 5 4 00

1

楼层

0 1 2 3 4 50

1

楼层

0

1

楼层

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

加速度峰值(m/s2)0 1 2 3 4 5

位移峰值(mm)

2

3


2

3


0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.60

加速度峰值(m/s2)

2

3


1

楼层

1

楼层

1

2

楼层

The shaking table test results of an eccentric building with MR dampers

0.0 0.5 1.0 1.5 2.0 2.5 3.00

加速度峰值(m/s2)0.0 0.5 1.0 1.5 2.0

0

位移峰值(mm)0 1 2 3 4 5

0

位移峰值(mm)


PZT friction dampers

Direct piezoelectricDirect piezoelectric effect--sensors

Inverse piezoelectric effect -- actuators



The tube piezoelectric actuators

Scheme of theScheme of the piezoelectric friction damper by Li (2005) The novel piezoelectric friction damper


PZT f i ti dPZT friction damper

The novel piezoelectric friction damper



Hysteretic curve of proposed PZT friction damperyste et c cu ve o p oposed ct o da pe



Time history curves of structural model for the e sto y cu ves o st uctu a ode o t eproposed PZT friction damper


SMA based controlShape memory effect (SME) refers to the material’s ability to return to a predetermined shape when heated beyond a transformation temperature.

High TemperatureCubic Form

B

Heat

CoolSMA Wire

TwinnedParallelogram Form C

Remove Force

Force ForceDeform

Deformed SMA Wire Deformed SMA Wire

DetwinnedParallelogram

DetwinnedP ll lLow TemperatureParallelogram

FormParallelogram Form

AD


SMA based controlThe superelasticity refers to the material’s ability to return to its original shape even after a large inelastic deformation.Condition: temperature is above Af (austenite finishing temperature)

σSelf-restoring ability

Condition: temperature is above Af (austenite finishing temperature).

σmfσms

σAustenite – martensite transformation

ms

Elastic deformationElastic deformation

ε

σasσaf

Martensite-austenite transformation

The stress-strain loop


SMA based control1. SMA concrete structures

箍筋φ

主筋

φ

箍筋φ

φ

φ

箍筋φ

φ

φ

箍筋φ

φ

孔洞 φ

等间距10mm 等间距10mm 等间距10mm

Experiment setup for SMA beams


SMA based control1. SMA concrete structures

10

6

8

10

RC A A(w)

mm

)

RC beam SMA beam

2

4

残余挠

度 (

m

0 3 6 9 12 15 18 210

加卸载循环次数

Comparison of load-deflection and residual deflectiondeflection


SMA based control1 SMA concrete structures1. SMA concrete structures

RC beam (loading) RC beam (unloading)

SMA beam (loading) SMA beam (unloading)


SMA based control2. SMA dampers

R t ti SMA iRestoration SMA wire

Energy dissipation SMA wire

Dissipation-restoration SMA damperDissipation restoration SMA damper


SMA based control

2000

2. SMA dampers1

f

LL

50010001500

N)

0.003Hz

2f

LL

，

1000-500

0500

输出力

( h h03

h

L LL

L L

-6 -4 -2 0 2 4 6-2000-1500-1000

输模型曲线试验曲线

h h04

h

1 1 2 2 3 3 4 4

L LL

F A A A A

位移( mm)

Dissipation-restoration SMA damper

1 1 2 2 3 3 4 4

Dissipation restoration SMA damper



3

4

5

N.m）

天津 : 0.4g E

I

EU

EU/E

I=55%

0

1

2

能量

（

Dissipation-restoration SMA damper

0 3 6 9 12 150

时间（ s）

Dissipation restoration SMA damper

SMA Damper

Shape Memory Alloys Damper

Dalian Univ. of Tech.Dalian Univ. of Tech.Department of Civ. & Hy. EngineeringDepartment of Civ. & Hy. Engineering 55

Experimental Results (1)

300

400

500

0.01Hz

300

400

500

0.05Hz

-200

-100

0

100

200

恢复

力

/N

-200

-100

0

100

200

恢复力

/N

-8 -6 -4 -2 0 2 4 6 8-500

-400

-300

200

位移 /mm-8 -6 -4 -2 0 2 4 6 8

-500

-400

-300

00

位移 /mm

200

300

400

500

N

0.1Hz

200

300

400

500

0.5Hz

N

-200

-100

0

100

恢复力

/N

-200

-100

0

100

恢复

力

/N

-8 -6 -4 -2 0 2 4 6 8-500

-400

-300

位移 /mm-8 -6 -4 -2 0 2 4 6 8

-500

-400

-300

位移 /mm

SMA 阻尼器在不同加载频率和不同位移幅值下的循环拉伸试验结果（初始位移0.6mm, 环境温度20℃）

Experimental Results (2)

300

400

500

600

0% 300

400

500

600

1%

200

-100

0

100

200

300

恢复

力

/N

-100

0

100

200

300

恢复力

/N

-6 -4 -2 0 2 4 6-600

-500

-400

-300

-200

-6 -4 -2 0 2 4 6-600

-500

-400

-300

-200

位移 /mm6 4 2 0 2 4 6

位移 /mm

300

400

500

600

2% 300

400

500

600

4%

-200

-100

0

100

200

恢复力

/N

-200

-100

0

100

200

300

恢复

力

/N

-6 -4 -2 0 2 4 6-600

-500

-400

-300

位移 /mm-6 -4 -2 0 2 4 6

-600

-500

-400

-300

200

位移 /mm 位移 /mm

SMA 阻尼器在不同初始位移和不同位移幅值下的循环拉伸试验结果（加载频率0.05Hz, 环境温度20℃）

Model of SMA Damper

Superelastic Energy-dissipated Hysteretic ModelHysteretic Model

1 ( , ' ')( ) ( ) ( ' ')k x oab oa bk k x sign x k x bc b c

( )

( ) ( )

( )

1 2 2'

1 2 1' '

1 2 2'

( ) ( ) ( , )( )

( )( ) ( ) ( , ' ')( ) ( ) ( , ' ')

b

b c

a

k k x sign x k x bc b cF x

k k x x sign x k x cd c dk k x sign x k x da d a


Analytical Example•结构模型

某6层偏心框架结构,ｘ方向偏心距ex = 6 m , 结构长度和宽度分别为48m和16m ,阻尼某6层偏心框架结构,ｘ方向偏心距ex = 6 m , 结构长度和宽度分别为48m和16m ,阻尼

比取为ζ1 =ζ2 = 0.05 。结构基本参数列于表1 。

y

xCRCM

ex


Simulation Approach

• （1）计算方法：采用法， =1.4；wilson • （2）地震波的选用：将场地类型分为三类：硬土、中

硬土、软土，所选用的地震波记录见表2；

场地类型地震波名地震名称震级加速度峰值cm/s-2 地震时间

选用的地震波

硬土迁安波唐山地震 6.3 118.91 1976.8.31

中硬土 EI Centro Imperial Valley 6.7 341.7 1940.5.18

软土天津波唐山地震 7.1 104.18 1976.11.15


Analitical Results

Tianjin Hospital Seismic Wavek=0.5 K=1.0 k=1.5 k=2.0 k=2.5 k=3.0

Tianjin Hospital Seismic Wave

结构反应

X0X 减振

率J X 减振率J X 减振

率J X 减振率J X 减振

率J X 减振率J

DmaxDmax_x 5.60 3.88 30.74 2.22 60.40 2.08 62.91 1.47 73.83 1.07 80.94 0.96 82.95

Dmax_y 6.52 4.61 29.26 2.93 55.11 2.39 63.26 1.63 74.99 1.42 78.21 1.44 77.96

Dmax_Z 0.31 0.21 32.59 0.19 40.89 0.16 48.43 0.16 50.16 0.15 52.08 0.14 55.27

Amax_x 465.6 491.3 -5.51 327.1 29.74 385.4 17.23 257.8 44.63 197.8 57.52 207.5 55.43

Amax_y 390.5 523.4 -34.0 393.1 -0.67 383.4 1.82 334.3 14.39 237.6 39.17 226.3 42.06

Amax_z 19.48 14.00 28.13 14.41 26.02 11.00 43.54 8.95 54.05 9.07 53.44 9.55 50.97


Tianjin Hospital Seismic Wavej p

6

No Control 6

8

No ControlW ith Control 0.3

0.4

No ControlWith Control

2

0

2

4

spla

cem

ent (

cm)

W ith Contro

-2

0

2

4

spla

cem

ent (

cm)

W ith Control

-0.1

0.0

0.1

0.2

Dis

plac

emen

t (cm

)

With Control

0 2 4 6 8 10 12 14 16-6

-4

-2

Dis

Time (s)0 2 4 6 8 10 12 14 16

-8

-6

-4

Dis

T im e (s)0 2 4 6 8 10 12 14 16

-0.4

-0.3

-0.2

0.1D

Time (s)

200

300

400

500

No Control W ith Control

2 ) 300400

500600

700800

m/s

-2)

No Control W ith Control

10

15

20

s-2)

No ControlWith Contro

-300

-200

-100

0

100

Acc

eler

atio

n (c

m/s

-2

-500

-400-300

-200-100

0

100

200

Acc

eler

atio

n (c

m

-10

-5

0

5

Acc

eler

atio

n (c

m/s

0 2 4 6 8 10 12 14 16-500

-400

Time (s)0 2 4 6 8 10 12 14 16

-800-700

-600

Tim e (s) 0 2 4 6 8 10 12 14 16-20

-15

Time (s)




Multi-dimensional SMA damperPlane View Site View

Multi-dimensional SMA damper



SMA

Plan

Multi-dimensional SMA damper Section


2. SMA dampers 2 21 2 cos 2L R S SR

Plane Control Force

2 22

2 23

2 cos 3 4

2 cos

L R S SR

L R S SR

2 24

2 25

2 2

2 cos 5 4

2 cos 3 2

2 7 4

L R S SR

L R S SR

L R S SR

2 26

2 27

2 28

2 cos 7 4

2 cos

2 cos 4

L R S SR

L R S SR

L R S SR

8 2 cos 4L R S SR

1,2, ,8n nT A n

M lti di i l SMA d

4

1n

nF T

Multi-dimensional SMA damper


2. SMA dampersVertical Control Force

2 2L R S

cos Sa cosa

L

8 cosF T

M lti di i l SMA dMulti-dimensional SMA damper


2. SMA dampersTorsional Control Moment

2 2'1 2 1 22 2 2 2 2 cosL D D D D

2 1'

sin2 2

D DhL

8M T h

M lti di i l SMA dMulti-dimensional SMA damper

Concluding Remarks

• We have invented some control devices and some of them have been applied to practical structures in recent years.

• Studies on control theories for nonlinear systems are still very limited so far and should be paid more attention in the future.

• Performance based method for all kinds of control systems should be developed to satisfy the engineering requirements.

• More smart materials and new technologies should be used to control the structural vibration subjected to dynamicto control the structural vibration subjected to dynamic loads.

Questions?Questions?Questions?Questions?

Dalian University of TechnologyDalian University of Technology

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