Th th k i l tThe earthquake simulatorActidyn QS 80Actidyn QS 80

J.L. Chazelas3/3/2011

Intervenant - date

OutlinesOutlines

P f i h k i h if• Performing earthquakes in the centrifuge• The main technologies• Specifying an earthquake simulatorSpecifying an earthquake simulator• The Actidyn QS80

– Basics of the QS80– Control of « pretest » and eathquake with Data Physics SignalStar

• Performances – Sines– Sines– Real-like earthquakes

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Performing an earthquake in the centrifugePerforming an earthquake in the centrifuge

S il

Bedrock

Soil

Soil

Prototype

Soil

Box

The physical model

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Performing an earthquake in the centrifugePerforming an earthquake in the centrifuge

The eath gravity defines the vertical

Z

Y

During rotation, the centrifuge gravity is the vertical of the model

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Main technologiesMain technologies

• Mechanical devices

• in Suzuki K., Babazaki R., Suzuki Y. 1994

• In Coe, Prevost et Scanlan , 19851

• in Madabhushi S.P.G., Schofield A.N., Lesley S , 1998

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Main technologiesMain technologies

Pi l t i ll t k• Piezoelectric cell stack

In Arulanandan K. & al, 1982.

• Electromagnetic device

In Fuji, 1991

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Main TechnologiesMain Technologies

The electro-hydraulic devices

•in Van Laak , Elgamal et Dobry , 1994

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Specifying an earthquake simulatorSpecifying an earthquake simulator

Classical specifications

Working centrifuge acceleration 20 to 100 g

Payload 50 to 300 kg (generally including box)

Maximum accélération 0.25 g prototype before Kobe0 40 g prototype since Kobe

Maximum velocity 1 m/s

0.40 g prototype since Kobe

Maximum displacement 5 mm model

Type of earthquake Sine / real-like scaled earthquake

Frequency bandwidth 20 – 200 Hz

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Actidyn QS 80 - Basicsy QA complementary equipment to the centrifuge

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Actidyn QS80 basicsy QDynamic equilibrium

PAYLOAD WEI

GHT

WEI

GHT

PAYLOAD

COUN

TERW

COUN

TERW

OIL BEARING

RETURN TANKOIL BEARING

CENTERING JACKS

BASKET PLATFORM

Payload + Counterweight in dynamic equilibrium + oil bearings

Vibration isolation

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Actidyn QS80 basics

counterweightsDynamic equilibrium

payload

Centeringjacks

h d li b i

Double action Jack

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hydraulic bearings

Actidyn QS80 basicsy QGuiding through multiaxis controller

Shaking

table

X

V ti l S ti

Hydraulic bearlings

Friction Paper Double action Jack

Y

• Free floating on oil bearings• No mechanical guiding in X Y Z directions

Vertical Section Top view

• No mechanical guiding in X, Y, Z directions • Movement controled by the coordination of 2 jacks

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Actidyn QS80 basicsy QThe multiaxis controller

TEAM Amplifiers

DATA PHYSICS I/O UnitABAQUS

(Pivot)

Drive 1(t)Drivre 2(t)

LVDT

Shaking table

DATA PHYSICS S/WSIGNAL STAR

(Command Room)

Accelerometers

Servos

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Actidyn QS80 basicsy QTuning Drives in a non linear context

• The jacks and the servo-valves j

ELECTRIC DRIVING SIGNAL

LEV

EL

• The electromagnet level transforms the « drive » in a low pressure circuit unbalance

N N

SS

O -

HY

DR

AU

LIC

« drive » in a low pressure circuit unbalance

• The hydraulic amplifier tranforms the unbalance in high pressure flow to jack back or forth h b

LOW PRESSURE E

LEC

TRO

chambers

• The leaks and the surplus are returned to a tank

ER

RA

ULI

C A

MPL

IFI

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HIGH PRESSURE

SUPPLY

JACK BACK

JACK FORTH

RETURN TO TANK

HY

DR

Actidyn QS80 basicsy QTuning Drives in a non linear context – Data Physics Signal Star

• 1st step : computing drives at low level ShakingD1 D21st step : computing drives at low level– Computation of transfert functions– 16 sequences of windowed white noise at low level

Shaking tableD1 D2

– Computation of an average transfer functionAcc1 Acc2Dj

AcciHij = ⎥⎦

⎤⎢⎣

⎡=

2221

1211HHHH

H

p g

• 2nd step : increasing the level of the drives and fitting to the reference signal – Computation of the first drive at low level

⎥⎦

⎤⎢⎣

⎡=⎥

⎦

⎤⎢⎣

⎡ −

ff

DD 1

2

1ReRe

H ⎥⎦

⎤⎢⎣

⎡

2

1AccAcc

record

– Fitting by repetition and correction of error in the time domain

⎦⎣⎦⎣ 2 ⎦⎣ 2

⎥⎦

⎤⎢⎣

⎡

corr2

corr1DD

⎤⎡D

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– Amplification of for a higher level⎥⎦

⎤⎢⎣

⎡

corr2

corr1DD

« Pretests » control with Data Physics Signal Star« Pretests » control with Data Physics Signal Star

Magnitude of H11 and H22

Phase of H11 and H22

The last white noise sequence

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Earthquake Control with Data Physics Signal StarEarthquake Control with Data Physics Signal Star

Comparing Acc1, Acc2 and Y table

Drives for Martinique JARA

Comparing Y,X,Z and Reference

Spectra at the table endSpectra at the table end

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PerformancesOutline specification figures

Model Scale Prototype Scale 80 gcModel Scale Prototype Scale – 80 gc

Total mass 2000kg

Payload 400kg

P l d di i L 1 0 5 h 0 6Payload dimension L=1m, w=0.5m, h=0.6m

Model in ESB Box L=0.8 m, w=0.35m, h=0.40m 64 m – 28 m – 32 m

Centrifuge G-level (in gc) 20 to 80 gc 1 g

Seismic G-level (in gh) 40 gh or 0.5 centrifuge acc. 0.5 g

Displacement peak 5 mm 40 cm

Velocity peak 1 m/s 1 m/s

Maximum test duration 1s 80 s

Frequency response (earthquake) 20 Hz to 300Hz 0.25 Hz to 3.75 Hz

Frequency response (sine) 20 Hz to 200Hz 0.25 Hz to 2.5 Hz

Input quality < 5%

Spurious movements and < 10%refRMS

refRMSYRMS

−

YRMSXRMS

YRMSZRMS

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PerformancesThe theoritical limit curve of an electo-hydraulic device

Reduction : 1/80Gravity : 80 gcPrototype Freq : 1.1 HzPrototype ampl. : 0.5 g

Reduction : 1/80Gravity : 80 gcPrototype Freq : 0.5 HzPrototype ampl. : 0.3 g

50 g 40 ghyp p g

g M

ag -

g

Limit curve for 60 gc tests

10 g

Log

20 Hz 100 Hz 200 Hz5 g

Log Freq. - Hz62 Hz32 Hz

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PerformancesT i i 40 80 H 16 h d lTuning sines – 40 gc – 80 Hz – 16 gh model

or 1gc – 2 Hz – 0.4 gh prototype

20.0 Y table

10.0

20.0 Y tableX tableZ tableRef Y1

-10.0

0

g

0 100m 200m 300m 400m-20.0

s

• Complementary quality criteria– Harmonics

Stability8.00

10.0

12.0

14.0

e, g

Y table¤X tableZ table

Y table

– Stability– Spurious frequencies

2.00

4.00

6.00

8.00

Mag

nitu

de

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0 50.0 100 150 200 250 300 350 400 0

Hz

Performanceson the way to Tune a sine – 40 gc – 140 Hz – 16 gh model

The 1st step increasing from « reference - 10 dB » to « reference -8 dB »

Difference in drives

2 shots at -8 dB

Harmonics in X

2 shots at – 6 dB

……

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Performancesfinal tuning of the sine – 40 gc – 140 Hz – 16 gh model

20.0 Y table14 0

final tuning of the sine – 40 gc – 140 Hz – 16 gh model 1 gc – 3.5 Hz – 0.4 gh prototype

10.0

20.0 Y tableX tableZ tableRef Y1

8.00

10.0

12.0

14.0

e, g

Y table¤X tableZ table

Y table

-10.0

0

g

Rms:11.0 Rms:10.5 Rms:909m2.00

4.00

6.00

Mag

nitu

de

204m 223m-20.0

s

Rms:909mRms:1.16

0 50.0 100 150 200 250 300 350 400 0

Hz

20.0

10.0

-10.0

0

g

Y tableX table

Rms:9.92 Rms:9.54 Rms:882m

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0 100m 200m 300m 400m-20.0

s

tabeZ tableRef Y1

Rms:882mRms:1.08

Performing real like earthquakesPerforming real-like earthquakes

• Original record filtered in the (20 – 300)/Ng Hz bandwidth• Scaling to cope with physical limits at model scale

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• Scaling to cope with physical limits at model scale0.5 g – 1 m/s – 5 mm disp.

Performing real like earthquakesPerforming real-like earthquakes

• Adapting the scaling to the bandwidth of the earthquake• Scaling the magnitude

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Thank for your attentionThank for your attention

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