Zafarana Presentation

7/28/2019 Zafarana Presentation

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Seismic Risk Assessment of Wind

Turbine Towers inZafarana Wind Farm Egypt

By

Dr. Heba Kamal

Dr. Ghada Saudi

Dr. Abdel Aziz khairy

April 2013


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Partners

1- Egyptian Partners

Housing & Building National Research Centre (HBRC)

Structures & Metallic Constructions Research Institute

Soil Mechanics& Geotechnical Engineering Institute

National Research Institute of Astronomy and Geophysics(NRIAG)

Seismological Department

New and Renewable Energy Authority (NREA)

2- American Partner

University of California, Irvine (UCI)

Civil & Environmental Engineering Department


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Introduction

Wind energy is one of the most important source of renewableenergy in Egypt.

Wind turbine technology has developed over the past years.

In considering structural loads on a wind turbine, even inseismically active regions such as Gulf of Suez , seismic loads are

regarded as less important compared to wind-inducedaerodynamic loads.

Seismic loads, however, should assume greater importance forwind turbines installed in regions where earthquakes occur.

A systematic loads analysis of turbines based on seismic hazard

deaggregation or specific turbine sites should be an integral partof the site assessment and structural integrity analysis of aturbine.


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Zafarana Wind Farm Egypt

Zafarana Wind Projectconsists of 8 projectsand will havea generating capacityof 545MW making itone of the largestonshore wind farms inthe world.

Existing wind farm at Zafarana site


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Loads acting on wind turbine


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Research Objective

The overall objective of the proposed research is the reductionin seismic risk by applying seismological, geotechnical andstructural studies to identify the expected seismic loads andpredict future seismic hazards that may affect the integrity ofthe wind towers at Zafarana site.

The current design of wind turbine towers and foundationsystems will be assessed for the future seismic risk at the Gulfof Suez zone.

The current trends in wind tower industry are expansion togreater heights and larger turbine capacity than ever before.

The new expected farm south of Zafarana farm and El-ZaytGulf will consist of a matrix of taller towers reaching from 80 m

to 100m.


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Research Tasks

1. Gathering data and documents about the turbine towersat Zafarana wind farm

2. Perform seismological studies of Zafarana and El ZaytGulf sites

3. Study the local site effects4. Perform dynamic soil structure interaction of the

foundation of wind turbine towers numerically byOpenSees, FAST, and FLAC 5.0.

5. Conduct In- Situ dynamic measurements for differenttypes of wind turbine towers in Zafarana farm

6. Numerical modeling of wind turbine towers

7. Model Comparison of Numerical and Measured Modes


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Project Schedules


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SEISMICITY AND SEISMIC HAZARD

ASSESSEMENT OF WIND TURBINE TOWERS INZAFARANA FARM, GULF OF SUEZ, EGYPT

BySeismic hazard team

Dr. Abd El-Aziz Khairy Abd El-Aal

Mr. Mohamed abdelhay

Mr. Ashraf Adely

National Research Institute of Astronomyand Geophysics


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Seismic risk versus seismic hazard

risk hazard vulnerability cost

Seismic Hazardis the probability of occurrence of a specified level ofground shaking in a specified period of time. But a more general

definition includes anything associated with an earthquake that may

affect the normal activities of people, i.e. surface faulting, ground

shaking, landslides, liquefaction, tectonic deformation, and tsunamis.

Vulnerabilityis the degree of damage caused by various levels ofloading. The vulnerability may be calculated in a probabilistic or

deterministic way for a single structure or groups of structures.

Seismic Riskis expressed in terms of economic costs, loss of lives orenvironmental damage per unit of time.

It isthe job of the geophysiciststo provide hazard assessments

(but not risk assessments.)


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Approaches to Seismic HazardAnalysis

Deterministic

The earthquake hazard for the site is a peak groundacceleration of 0.35g resulting from an earthquake

of magnitude 6.0 on the Balcones Fault at a distance of12 miles from the site.

Probabilistic

The earthquake hazard for the site is a peak groundacceleration of 0.28g with a 2 percent probability of being

exceeded in a 50-year period.


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Deterministic vs Probabilistic

Deterministic

- Consider of small number of scenarios (Mag, dist,number of standard deviation of ground motion)

- Choose the largest ground motion from cases

considered

Probabilistic

- Consider all possible scenarios (all mag, dist, andnumber of std dev)

- Compute the rate of each scenario- Combine the rates of scenarios with ground motion

above a threshold to determine probability ofexceedance


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. Steps ofprobabilistic seismichazard analysis for agiven site:

(1) definition ofearthquake sources,(2) earthquakerecurrencecharacteristics foreach source, (3)

attenuation of groundmotions withmagnitude anddistance, and (4)ground motions forspecified probability ofexceedance levels

(calculated bysumming probabilitiesover all the sources,magnitudes, anddistances


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Tectonic elements aroundEgypt

Tectonic boundaries ofthe EasternMediterranean Region.Seismicity data fromENSN and NEIC. Thefollowing Acronymsrepresent: AEG-Aegean

Sea; Al-Alexandria City;CY-Cyprus; ERA-Eratosthenes Seamount;FL-Florence; IB-IonianBasin; MR-Mediterranean Ridge;LEV-Levantine Basin;LF-Levant Fault; ND-Nile Delta. Smalldiamond indicates thelocation of Cairo andBeni Suef cities. AbuZenima is indicated bythe heavy red diamond.


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Recent seismicity

of Egypt from1900-2012(unifiedcatalogue Mw)


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Recent Seismicity

Seismicity of the northern Red Sea region from 1900 to 2010. redrectangular is the city of Abu Zenima


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The seismicty from 1900 to 2012 inand around the wind farm Zafaran, redsea


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Map shows therecordedearthquakesused tocalculate,seismotectonicmodel andseismic hazardwithin a circleof radius 350

km from thefarm site


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seismtectonicmodel usedto calculate

seismichazardestimationfor the farm

site


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Zone M max M min BETA b LAMBDA Averg. Depth

Mmax

obs.

1 6.45 +- 0.38 3 2.29 +- 0.17 1.00 +- 0.0 6.919 +- 1.299 14.5 6.2

2 6.55 +- 0.29 3 2.09+-0.32 0.91+-0.14 3.051 +- 0.764 15.17 6.3

3 5.55 +- 1.90 3 2.66 +- 0.45 1.16 +- 0.19 1.430 +- 0.405 14.72 5.3

4 5.15 +- 0.44 3 1.15 +- 0.00 0.60+-0.25 0.605 +- 0.218 14.42 4.9

5 6.25 +- 0.38 3 2.50 +- 0.31 1.09 +- 0.14 2.064 +- 0.565 13.03 6

6 5.3 3 1.55 +- 0.71 0.67 +- 0.31 0.383 +- 0.146 12.52 5.3

7 3.95 +- 0.88 3 3.42 +- 0.00 1.48 +- 0.00 0.337 +- 0.173 14.82 3.7

8 4.40 +- 00 3 3.45 +- 0.00 1.50 +- 0.00 11.28 4.4

9 6.75 +- 0.22 3 1.90 +- 0.13 0.82 +- 0.05 5.569 +- 1.047 15.63 6.5

10 5.25 +- 0.23 3 1.36 +- 0.26 0.59 +- 0.11 2.753 +- 0.641 23.15 5

11 5.65 3 1.15 +- 0.00 0.50 +- 0.00 5.65 +- 2.28 33.27 5.4

12 5.55 +- 0.24 3 1.15 +- 0.00 0.50 +- 0.00 1.294 +- 0.319 25.97 5.313 6.15 +- 0.30 3 1.15 +- 0.00 0.50 +- 0.00 6.600 +- 1.786 27.27 5.9

14 5.65 +- 0.50 3 1.15 +- 0.00 0.50 +- 0.00 1.917 +- 0.605 29.33 5.4

15 6.45 +- 0.26 3 1.16 +- 0.00 0.50 +- 0.00 1.611 +- 0.353 25.25 6.2

16 5.65 +- 3.02 3 1.15 +- 0.00 0.50 +- 0.00 0.244 +- 0.131 33 5.4

17 5.35 +- 0.36 3 1.18 +- 0.49 0.51 +- 0.21 0.508 +- 0.182 18.07 5.1

23 6.55 +- 0.68 3 1.25 +- 0.27 0.54 +- 0.12 1.060 +- 0.264 22.64 6.3

24 6.35 +- 0.35 3 1.93 +- 0.26 0.84 +- 0.11 1.561 +- 0.384 26.14 6.125 3.95 +- 0.65 3 3.45 +- 0.00 1.50 +- 0.00 0.472 +- 0.226 12.36 3.7

26 6.35 3 1.44 +- 0.43 0.62 +- 0.19 0.569 +- 0.212 26.125 6.1

35 6.35 3 1.30 +- 0.45 0.56 +- 0.19 0.717 +- 0.275 17.59 6.1

36 5.35 3 3.39 +- 0.00 1.47 +- 0.00 2.766 +- 0.672 18.48 5.1

37 5.35 +- 0.45 3 3.45 +- 0.00 1.50 +- 0.00 7.752 +- 1.614 20.76 5.1

38 6.05 +- 00 3 3.45 +- 0.00 1.50 +- 0.00 4.630 +- 0.961 12.08 5.8


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Seismic hazard results at farm site


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Seismic hazard results atfarm site


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Seismichazard

results atfarm sitefor returnperiod 100


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Seismichazard

results atfarm sitereturnperiod 475


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The obtained seismic hazardresults for the wind farm site

acceleration

(gal)

100 yr return

period475 yr return period

PGA 46.024 92.131

0.1 134 245.35

0.2 98.327 206.44

0.3 73.289 159.47

1 26.395 55.858

2 13.648 27.698


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Ground motion parameters:

1- Source parameters.

2- Path parameters.

3- Site parameters.

Stochastic method

1-Peak ground acceleration.2- Peak ground velocity.3- Peak ground displacement

4- Response spectrum

Simulation of the biggest effectedearthquakes from different seismicsources to the wind farm site


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Comparison between ground motionamplification at bedrock site and soilsite

Simulation of time history of the 1995


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Simulation of time history of the 1995earthquake Mw 7.2 at the wind farm sitehypocentral distance 225 km from the windfarm site



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Simulation of time history of the 1992earthquake Mw 6 at the wind farm sitehypocentral distance 146 km from wind farmsite

Simulation of time history of 1983


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Simulation of time history of 1983earthquake Mw 5.3 at wind farm sitehypocentral distance 98.5 km from windfarm site



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Simulation of time history of the 1969earthquake Mw 6.7 at the wind farm sitehypocentral distance 228 km from the windfarm site


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SUMMARY

1- In the current study, I presented and discussed the probabilistic

seismic hazard assessment (PSHA) and simulation technique at the

wind farm site, Zafarana, Egypt that is based on spectral parameters.

2-The PSHA build upon extensive research and database compilation

3-the seismic source model used, the ground motion adopted and theuse of the spectral parameters for the first time at farm site, will permit

site-specific uniform hazard spectra to be available, and hence allow

improved earthquake-resistant design

4-The hazard is calculated at the Bedrock condition

5- We used the 10% and 20% chance of exceedence in 50 years,which is corresponding to about 475 and 100 years return period.

6- the simulation techinque is used to obtain time history at the wind

farm site for the biggest effective earthquakes from different seismic

sources.


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GROUND RESPONSE ANALYSIS OF

ZAFARANA WIND FARM, GULF OF SUEZ,

EGYPT

By

Dr. Heba Kamal

Soil Mechanics and Geotechnical Engineering

Institute, Housing and Building National ResearchCenter (HBRC)


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Introduction

Seismic micro hazard zonation is the first step towards a seismic

risk analysis and mitigation strategy.

Essential here is to obtain a proper understanding of the local

subsurface conditions and to evaluate ground shaking effects.

In this study, the Zafarana Wind Farm , will be evaluated with

respect to site amplification and site period.

Boreholes from previous investigations will be complied to

determine the variation of the soil profile as well as the

characteristics of the soil layers within the study site.


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Introduction

One dimensional ground response study will be done using

program SHAKE2000 for equivalent linear analysis and program

DEEPSOIL for non linear analysis.

The synthetic and real ground motion generated and dynamicsoil properties will be used for one dimensional ground analysis

to study the site response of soil columns.

The amplification of soil columns, peak horizontal acceleration

variations and spectral acceleration both at rock level and groundsurface will be studied and presented.


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RESEARCH METHODOLOGY

For seismic response modelling in the topic of seismicmicro hazard assessments the information needed ingeneral as follows:

Detailed geotechnical data (shear wave velocity, unit

weight, shear modulus and damping and modulusreduction curve information )

Detailed geology data available near the site (boreholelog information With defined material and formations)

Digital seismic accelerograms (from real earthquake and

synthetic one) Depth to bedrock level

Ground water level


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Earthquake Scenarios

Three Earthquake Scenarios was used in thisstudy as follow:

Date

Day M. Yr.

Origin Time

H Mn Sec

Location

Lat. Long.

Depth

(km)M

S

31 03 1969 07 15 54.4 27.60 33.90 20 6.9

12 10 1992 13 09 55.5 29.77 31.14 21 5.3

22 11 1995 04 15 11.9 28.82 34.79 10 7.3


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Geotechnical and Geological

Features

Geological FeaturesThe geological features indicate that the Zafarana

project area consists of coastal and wadi deposits .

There are no intensive faults at Zafarana area.However, some faults, taking the NW-SE trend,

appear at the area between Quseir and Ras Ghareb

and also between Marsa Alam and Quseir.


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The Geological Map of Red Sea

Governorate


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Geotechnical and Geological

Features

Geotechnical Features Based on the results of the previous site investigation

and laboratory testing of 595 boring holes

subsurface formation consists, in general, of fivelayers described as follows:

Wadi Deposit

Clay

Clay Stone

Sand

Sand Stone


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Wadi Deposit

Reddish brown to yellowish brown wadi eposit

that consist of gravel, sand, silt, clay and iron

oxides.


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Clay layer

Hard greyish brown clay with interbedded band of

clay stone and sand stone pieces and traces of

iron oxides


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Clay Stone layer

Reddish to yellowish bown very weak to medium

hard sandy claystone interbedded by thin to thick

band of sand or sand stone


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Sand Layer

Yellow to reddish brown sand with different

precent of silt, could be cemented or clayey the

layer is interbedded with sandstone or clay stone

pieces , calcareous and with traces of iron oxides


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Sand Stone Layer

Yellow to reddish brown fine to medium grained

sands interbedded by thin to thick band of clay

stone . It is sained by iron oxides


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Site Response Analysis forZafarana 3

The site investigation consists of 46 boringholes the analysis was done on 3representative boring holes as following:


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0

5

10

15

20

25

30

35

0 0.05 0.1 0.15 0.2

a max with depth

Darendeli,

2001.Shedwan, 1969

a max with depth

Darendeli,2001.Dahshor, 1992

a max with depth

Darendeli, 2001.Al-

Akaba, 1995


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0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.01 0.1 1 10 100

Spectral Acceleration

with

time,Darendeli,2001.S

hedwan, 1969


with

time,Darendeli,2001.D

ahshor, 1995


withtime,Darendeli,2001.A

l-Akaba, 1995


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0

5

10

15

20

25

30

35

0 0.05 0.1 0.15 0.2

a max with depth

Darendeli,

2001.Shedwan, 1969

a max with depth

Darendeli,

2001.Dahshor, 1992

a max with depth

Darendeli, 2001.Al-

Akaba, 1995


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0

0.1

0.2

0.3

0.4

0.5

0.6

0.01 0.1 1 10 100


with


hedwan, 1969


with


ahshor, 1995



l-Akaba, 1995


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0

5

10

15

20

25

30

35

0 0.1 0.2 0.3

a max with depth

Darendeli,

2001.Shedwan, 1969

a max with depth

Darendeli,

2001.Dahshor, 1992

a max with depth

Darendeli, 2001.Al-

Akaba, 1995


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0

0.2

0.4

0.6

0.8

1

1.2

0.01 0.1 1 10 100


with


hedwan, 1969


with


ahshor, 1995



l-Akaba, 1995


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0

5

10

15

20

25

30

35

0 0.05 0.1 0.15 0.2

a max with depth

Darendeli,

2001.Shedwan, 1969

a max with depth

Darendeli,

2001.Dahshor, 1992

a max with depth

Darendeli, 2001.Al-

Akaba, 1995


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0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.01 0.1 1 10 100


with


hedwan, 1969


with


ahshor, 1992



l-Akaba, 1995


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0

5

10

15

20

25

30

35

0 0.05 0.1 0.15 0.2

a max with depth

Darendeli,

2001.Shedwan, 1969

a max with depth

Darendeli,

2001.Dahshor, 1992

a max with depth

Darendeli, 2001.Al-

Akaba, 1995


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0

0.05

0.1

0.15

0.2

0.25

0.01 0.1 1 10 100


with


hedwan, 1969


with


ahshor, 1995



l-Akaba, 1995


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0

5

10

15

20

25

30

35

0 0.05 0.1 0.15 0.2

a max with depth

Darendeli,

2001.Shedwan, 1969a max with depth

Darendeli,

2001.Dahshor, 1992

a max with depth

Darendeli, 2001.Al-

Akaba, 1995


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0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

0.01 0.1 1 10 100


with


hedwan, 1969


with


ahshor, 1995



l-Akaba, 1995


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0

5

10

15

20

25

30

35

0 0.05 0.1 0.15 0.2

a max with depth

Darendeli,

2001.Shedwan, 1969

a max with depth

Darendeli,

2001.Dahshor, 1992

a max with depth

Darendeli, 2001.Al-

Akaba, 1995


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0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.01 0.1 1 10 100


with


hedwan, 1969


with


ahshor, 1992



l-Akaba, 1995


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SUMMARY

1- In the current study, I presented and discussed the ground response

analysis using equivalent linear method by SHAHE2000.

2- The amax with depth and response spectrum at surface were

introduced for the three earthquakes scenarios .

3- The earthquake waves is amplified up to 0.3g if the upper layers are

wadi deposit and clay layer.

4- the earthquake waves is deamplified if the upper layers are

claystone or sand stone.

NUMERICAL MODELLING OF VESTAS


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WIND TURBINE TOWER, ZAFARANA WIND

FARM

ByDr. Ghada Saudi

Structure and Metallic Engineering Institute,

Housing and Building National Research Center(HBRC)

Seismic Risk Assessment of Wind


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Turbine Towers

Structure Studies

Ambient Vibration Testing

InputLinear

SystemOutput

ambient excitation

(wind, micro-tremors, etc)

acceleration response

measurement

Natural frequencies

Mode shapes

Modal damping ratios

Experimental modal analysis & Dynamic Characteristics


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Various mode shapes as obtained from the theoretical


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pmodel

Mode1

1.204 Hz

Mode2

1.204 Hz

Mode3

6.509 Hz

Mode4

6.509 Hz

Mode5

17.218 Hz

Mode6

17.218 Hz

Mode7

19.077 Hz

Theoretical

modal


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