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8/16/2019 shake table analysis
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DESSERT TION ON
Experimental Analysis Of Structure
Using Shake Table
PRESENTED
BY
Pathan Majead Hashamsab
Under the Guidance of
Dr. P. B. MURNAL
Department of Applied MechanicsGovernment College of Engineering,
Aurangabad.(2015 - 2016) 1
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Contents:
1.ntro!uction.
".#iterature sur$ey.
%.Ob&ecti$e.
'.System !e$elopment.
(.)eferences.
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ntro!uction:
Many structures have their fundamental frequencies of vibration within the band of
frequencies .
Structure amplifies the seismic ground vibrations and produces undesirable level of
accelerations .
Cost effective procedure to mitigate such effects is to detach the structure from the
earthquake ground motions.
Main Objective is to keep its response within limits.
The effectiveness of an isolation system depends upon the dynamic characteristics of
the earthquake ground motion and the building superstructure.
eneficial effects of the isolation system may be significantly reduced for both
moderate and strong earthquakes .
!
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*igure 1. +arameters of T,o -egreeof*ree!om solate!"
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!quation of motion in matri" form#
y solving above equation we get characteristic of base isolation.
#
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#iterature sur$ey:
Anoop Mokha(1991):
•$ si" storey model with three bays is used for performing the analysis.•The columns were bolted to two heavy sections and the bearings
were placed between these beams and the shake table.
•The %&S bearings are used.
•$spect ratio of height of model to distance between bearings is '.'(.•&ermanent displacement at the bearings was very small and) in
particular) less than *+ of the bearing design displacement.
• ,n tests with the !l Centro motion) it was shown that the isolated
structure could sustain a peak table acceleration si" times greater than
that it could sustain under fi"ed-base conditions.
$
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Hsiang-Chuan Tsai(1995):•$ five-storey base-isolated building subjected to different earthquake
records.
•$ tuned mass damper is used to reduce the lateral deformations of
isolator.
•little effect on structural response during the first few seconds of
earthquake e"citation.•There e"ists a critical value for the damper damping.•The tuned-mass damper to the structure would enhance the structural
response if the input frequency is lower than the natural frequency of the
structure.
•The reduction by the tuned-mass damper becomes more prominent if the
isolation system has less damping.
•The proposal for the accelerated tuned-mass damper is only conceptional
and idealistic.
%
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T. +inkae, 9'66':#5o!el an! !amper:
•'6-storey reinforced concrete building is used.
•$ TM; is installed on top of the structure to reduce the displacement and the
damage.
•oth harmonic and the 2
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). 7iannini 2"3384:
5o!el an! isolation system:
•$ steel liquid storage tank with a diameter of > m is used.
•Two type of isolators are used as high damping rubber bearings and sliding
isolators with elasto-plastic dampers.
Conclusion:
•oth the isolators work effectively in reducing the total pressure generated by
the earthquake on the tank wall.
• $ low increasing of the oscillation amplitude of the liquid surface has been
observed.
11
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A9lan A-A 2"3114:
5o!el an! solation system:
•The '-storey special moment resistant frame is used.
• Solid rubber bearings 9S1: and ?ollow rubber bearings 9?1: are used.
Conclusion:
•The equivalent viscous damping of ?1 is >+ higher than S1.
•1ecorded floor acceleration decrements of the ?1 are @.2+) /.'+ and 26.
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Tomas9 *alborski 2"31"4:
5o!el an! isolation system:
• $ single-storey structure model is used.
•The type of the isolation system is elastomeric polymer isolator.
Conclusion :
•The structure with the !& showed a significant decrease in lateral
acceleration.
•The free vibration test showed a considerable increase in structural damping.
•The use of the !& showed a substantial improvement in dynamic properties
by reducing the structural vibrations.
1!
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#. Tashko$ ; #.
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Emiliano 5atta 2"31%4 : 5o!el an! !amping:
•single and multi degrees-of-freedom linear structures are used.
•Tuned mass dampers are used as damping devices.
Conclusion :
• $s far as peak displacement is concerned) the effectiveness of a TM; on a
S;O% structure is similar to that of a TM; of equal effective mass ratio on a
M;O% structure.
•1MS velocity or peak acceleration is considered) the effectiveness in theM;O% case decreases with an increase in the structural period as a result of
uncontrolled higher modes) whereas for the S;O% case) it keeps nearly
constant.
1#
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A. #ucchini 2"31'4:
5o!el an! !amping:
•/-story shear-type building.
•TM;s are installed in the building where more free spare space is available
to house the devices) which is usually at the roof or at the top floor.
•Conclusion:
•Aith the increase of the total mass of the TM; system) its performance tends
to improve the building response
•Aith the increase of the uncertainty level) it has been observed that period
and damping of the TM; units increase
1$
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Ob&ecti$e:
•The structure model is subjected to harmonic loading analyBed e"perimentally
under different conditions .
Ob&ects :
• To study the behavior of the structural model when it is fi"ed.
•To analyBe the structural model when it is base isolated.
•To study the behavior of the structural model when TM; is used.
•To study the behavior of the structural model when it is base isolatedand TM; is used.
•To make the comparison of the above cases.
1&
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SSTE5 -E=E#O+5ETShake Table Use!:
•The electric motor driven shake table is used for applying the harmonic
loading to the structural model.
*ig Electric motor !ri$en shake table *ig. Cam > follo,er arrangement *ig. Types of cams
1'
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5O-E# TO ?E USE-:
Geometric data of the structure:
r! "o! #art $imension in mm
Depth idth *ength
1 Column ! # 1
+lab 1 1# !
he column and slab are made up ofaluminum.
Mass of structure is %.1"-g.
ime period of structure is .!$ sec.
Ta%&e : $imension of mode&
*ig. Three storie! mo!el.
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1
he natural freuencies and mode shapes of model/
'1 ! H*
0 %."% 20! 11.$2
he top 3oor acceleration and the relative displacement of structure is
calculated using sha-e table . he follo4ing graph sho4s top 3oor acceleration for di5erent freuenciesfor 67ed structure.
" $ & 1 1 1"
1
!
"
#
$
+re,uenc(H*)
Top +&oor Acce&eration(g)
*ig. *re@uency $s Top *loor Acceleration.
. Mode .. Mode ... Mode
1 1 1.%" .#%1 81.1%
!.#'1 81.1& ."&
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solate! structure :
The structure to be isolated 01 isolation system is selected and designed the dimension
comes out as sown in figure.
The stiffness of 01 is about @6 3m.
Springs are used as isolation system so that to achieve such a small stiffness.
"
"
!
!
"$
*ig. -imension of #)? 2!imensions n mm4
/ f
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/eferences:•$noop Mokha D!"perimental Study Of %riction-&endulum ,solation SystemE)
Fournal of Structural !ngineering) Gol. 22@) 3o. >) &aper 3o. '(@4/.2
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•1. =iannini DShaking Table Tests Ipon $ ase ,solated Steel 0iquid
storage TankE) The2>th Aorld Conference on !arthquake !ngineering
October 2'-2@) '66/) eijing) China.• $Blan $dnan DSeismic ase ,solation of Steel %rame Structure by ?ollow
1ubber earingsE) =aBi Iniversity Fournal of Science vol '>) 3o. >) />2-/(4)'622.•TomasB %alborski) DShaking table e"perimental study on the base isolation
system made of polymer bearingsE) 2(th Aorld Conference on !arthquake
!ngineering 0,SO$ '62'.
•0. Tashkov K 0. Lrstevska DComparison etween Three ase ,solationSystems-Shake Table Test StudiesE) '624.•!miliano Matta D!ffectiveness of Tuned Mass ;ampers against =round
Motion &ulsesE) Fournal of Structural !ngineering) Gol.24
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•$. 0ucchini D1obust ;esign of Tuned Mass ;amper Systems for Seismic
&rotection of Multistory uildingsE) Fournal of Structural !ngineering)'62>.
• %.C. &onBo DShaking table tests of a base isolated structure with double
concave friction pendulumsE) 3JS!! Conference paper 3o.6>4)'62>.
• Leri 0. 1yan D,nfluence of Gertical =round Shaking on ?oriBontal
1esponse of Seismically ,solated uildings with %riction earingsE) Fournal
of Structural !ngineering)'62(.
• Manual of the Millenium ltd of shake table.
#
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Thank you!
$