Research Article AP1000 Shield Building Dynamic Response...

9
Research Article AP1000 Shield Building Dynamic Response for Different Water Levels of PCCWST Subjected to Seismic Loading considering FSI Daogang Lu, Yu Liu, and Xiaojia Zeng Beijing Key Laboratory of Passive Nuclear Safety Technology, North China Electric Power University, Beijing 102206, China Correspondence should be addressed to Yu Liu; [email protected] Received 8 October 2014; Accepted 12 January 2015 Academic Editor: Alejandro Clausse Copyright © 2015 Daogang Lu et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Huge water storage tank on the top of many buildings may affect the safety of the structure caused by fluid-structure interaction (FSI) under the earthquake. AP1000 passive containment cooling system water storage tank (PCCWST) placed at the top of shield building is a key component to ensure the safety of nuclear facilities. Under seismic loading, water will impact the wall of PCCWST, which may pose a threat to the integrity of the shield building. In the present study, an FE model of AP1000 shield building is built for the modal and transient seismic analysis considering the FSI. Six different water levels in PCCWST were discussed by comparing the modal frequency, seismic acceleration response, and von Mises stress distribution. e results show the maximum von Mises stress emerges at the joint of shield building roof and water around the air inlet. However, the maximum von Mises stress is below the yield strength of reinforced concrete. e results may provide a reference for design of the AP1000 and CAP1400 in the future. 1. Introduction e passive containment cooling system water storage tank is key equipment which should remain operational aſter earthquakes to ensure the passive safety of the AP1000. As the quality of PCCWST is approximately 3000 ton. e presence of water in water tank might have an important influence on the dynamic behavior of the shield building and can affect the safety of the shield building under seismic loading from an earthquake with long-period component [1]. As for conventional assessment of nuclear equipment, the response spectrum focuses on the short-period seismic com- ponent because there is little equipment with fundamental period above 5 s [2]. However, for PCCWST, the sloshing frequency is beyond that value. erefore, it is necessary to investigate the dynamic behavior of the elevated water tank under long-period earthquake considering FSI phenomenon especially the water sloshing. Fluid-structure interaction of elevated tank has been studied numerically and experimentally by many researchers. Livao˘ glu and Do˘ gang¨ un [3] presented a review of simplified seismic design procedures for elevated tanks and the appli- cability of general-purpose structural analyses programs to fluid-structure-soil interaction problems for these kinds of tanks. It turned out that the distributed added mass with the sloshing mass is more appropriate than the lumped mass assumptions for finite element modelling. Moslemi et al. [4] adopted the finite element (FE) technique to investigate the seismic response of liquid filled tanks considering the effect of tank wall flexibility and sloshing of the water free surface. El Damatty conducted a small scaled liquid filled conical tank model to study the elevated water tank. He found a very good agreement between the experiment and analytical model for the fundamental sloshing frequency. Masoudi et al. [5] discuss the failure mechanism of elevated concrete tanks with shaſt and frame staging (supporting system) along with seismic behavior of these construction types. e AP1000 shield building has also been studied by researchers recently. Lee et al. [6] and [1] investigated the influence of elevation and shapes of air inlets on AP1000 shield building by FEM. e simulation result indicated that an optimal parametric design for air intake must be implemented around the middle of the shield building, with 16 circular or oval shaped air intake. e PCCWST is the water source of cooling water which guarantees the 72 hours safety without operator actions. However, with the water draining to cool down the inner steel containment, the change of huge water volume may Hindawi Publishing Corporation Science and Technology of Nuclear Installations Volume 2015, Article ID 840507, 8 pages http://dx.doi.org/10.1155/2015/840507

Transcript of Research Article AP1000 Shield Building Dynamic Response...

Page 1: Research Article AP1000 Shield Building Dynamic Response ...downloads.hindawi.com/journals/stni/2015/840507.pdf · AP1000 Shield Building Dynamic Response for Different Water ...

Research ArticleAP1000 Shield Building Dynamic Response for Different WaterLevels of PCCWST Subjected to Seismic Loading considering FSI

Daogang Lu Yu Liu and Xiaojia Zeng

Beijing Key Laboratory of Passive Nuclear Safety Technology North China Electric Power University Beijing 102206 China

Correspondence should be addressed to Yu Liu appleplantergmailcom

Received 8 October 2014 Accepted 12 January 2015

Academic Editor Alejandro Clausse

Copyright copy 2015 Daogang Lu et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Huge water storage tank on the top of many buildings may affect the safety of the structure caused by fluid-structure interaction(FSI) under the earthquake AP1000 passive containment cooling system water storage tank (PCCWST) placed at the top of shieldbuilding is a key component to ensure the safety of nuclear facilities Under seismic loading water will impact the wall of PCCWSTwhich may pose a threat to the integrity of the shield building In the present study an FE model of AP1000 shield building is builtfor themodal and transient seismic analysis considering the FSI Six different water levels in PCCWSTwere discussed by comparingthe modal frequency seismic acceleration response and von Mises stress distribution The results show the maximum von Misesstress emerges at the joint of shield building roof and water around the air inlet However the maximum von Mises stress is belowthe yield strength of reinforced concrete The results may provide a reference for design of the AP1000 and CAP1400 in the future

1 Introduction

The passive containment cooling system water storage tankis key equipment which should remain operational afterearthquakes to ensure the passive safety of the AP1000 As thequality of PCCWST is approximately 3000 ton The presenceof water in water tank might have an important influence onthe dynamic behavior of the shield building and can affectthe safety of the shield building under seismic loading froman earthquake with long-period component [1]

As for conventional assessment of nuclear equipment theresponse spectrum focuses on the short-period seismic com-ponent because there is little equipment with fundamentalperiod above 5 s [2] However for PCCWST the sloshingfrequency is beyond that value Therefore it is necessary toinvestigate the dynamic behavior of the elevated water tankunder long-period earthquake considering FSI phenomenonespecially the water sloshing

Fluid-structure interaction of elevated tank has beenstudied numerically and experimentally bymany researchersLivaoglu and Dogangun [3] presented a review of simplifiedseismic design procedures for elevated tanks and the appli-cability of general-purpose structural analyses programs tofluid-structure-soil interaction problems for these kinds of

tanks It turned out that the distributed added mass withthe sloshing mass is more appropriate than the lumped massassumptions for finite element modelling Moslemi et al [4]adopted the finite element (FE) technique to investigate theseismic response of liquid filled tanks considering the effectof tank wall flexibility and sloshing of the water free surfaceEl Damatty conducted a small scaled liquid filled conicaltank model to study the elevated water tank He found avery good agreement between the experiment and analyticalmodel for the fundamental sloshing frequencyMasoudi et al[5] discuss the failure mechanism of elevated concrete tankswith shaft and frame staging (supporting system) along withseismic behavior of these construction types

The AP1000 shield building has also been studied byresearchers recently Lee et al [6] and [1] investigated theinfluence of elevation and shapes of air inlets on AP1000shield building by FEM The simulation result indicatedthat an optimal parametric design for air intake must beimplemented around the middle of the shield building with16 circular or oval shaped air intake

The PCCWST is the water source of cooling water whichguarantees the 72 hours safety without operator actionsHowever with the water draining to cool down the innersteel containment the change of huge water volume may

Hindawi Publishing CorporationScience and Technology of Nuclear InstallationsVolume 2015 Article ID 840507 8 pageshttpdxdoiorg1011552015840507

2 Science and Technology of Nuclear Installations

influence the dynamic behavior of shield building underseismic loading In current study a finite element modelof AP1000 shield building was established and the differentwater levels were discussed for both modal and transientanalysis The FEM results may also provide a reference fordesign of the AP1000 and CAP1400 in the future

2 Theory of Fluid-Structure Interaction

For a structural system the governing equation derived fromfinite element formulation can be obtained as follows

119872 + 119862 + 119870119906 = 119865 (1)

where119872 119862 and 119870 are mass damping and stiffness matrixfor structure and 119906 is the displacement vector 119865 is the totalforce applied by other systems However for fluid-structureinteraction problem the FSI can be expressed by coupling thegoverning equation of the structure and fluid at the interfaceThe interface force caused by the fluid pressure at the interfaceis transferred to the structure So the 119865 of equation can beextended to

119865 = 1198651015840+ 119865119901 (2)

where 119865119901 is the integration of fluid pressure on the fluid-structure interface and 1198651015840 is the external force excluding 119865119901The fluid pressure field can be derived from the followingequation assuming the fluid as incompressible and inviscid

1

119888

1205972119875

1205971199052minus nabla2119875 = 0 (3)

where 119888 is the fluid sound speed and 119905 is the time Thedetailed formula deduction can refer to the work by Choiet al [7] The final matrix equation involves nonsymmetricand stiffness matrix The eigenvalues of the coupled problemcan be obtained with unsymmetrical algorithm for modalanalysis by ANSYS

For FEM transient analysis the Newmark algorithm is aneffective way of solving the structural response InNewmarkrsquosalgorithm Rayleigh damping is adopted for defining thedamping denoted as

119862 = 120572119872 + 120573119870

120572 =212058512059611205962

1205961+ 1205962

120573 =2120585

1205961+ 1205962

(4)

where 120572 and 120573 are the mass and stiffness proportionalRayleigh damping coefficient respectively The 120585 120596

1 and 120596

2

are damping ratio the first and second undamped naturalfrequency of the structure According to the AP1000 DCD[8] the damping ratio 7 is adopted Inmaterials science andengineering the von Mises yield criterion is used to predictyielding of materials A material is said to start yielding whenits von Mises stress reaches a critical value known as theyield strength In this paper the yield strength of reinforcedconcrete 276MPa is used according to the AP1000 DCD

P1

P2 P3

Z

XY

Figure 1 The geometry of shield building

Table 1 The geometry of shield building

Geometry Dimension(m)Height Diameter Thickness

Shield building 71 442 09PCCWST 58115 90271 05Water 86 90271 mdash

Table 2 The material properties

Material Density(kgm3)

Elastic module(GPa) Poisson ratio

Uniform reinforcedConcrete 2300 335 02

Water 1000 mdash mdash

3 Structural Assessment of AP1000 PCCWSTby FEM Model

31 AP1000 PCS The main part of the structure for shieldbuilding includes shield building wall with 16 rectangularcooling air intakes the shield building roof PCCWST andwater shown as Figure 1 The uniform reinforced concretemodel is adopted to simulate shield building The materialproperties and geometric conditions are shown in Tables1 and 2 In this paper six different water levels (Table 3)corresponding to the 100 80 60 40 20 and 0of operational water volume are analyzed to figure out thestructure assessment of water level decreasing owing to thewater draining in accident scenario Both modal analysis andtransient analysis are carried out for six different water levels

32 FEMModel The pressure-based fluid element Fluid30 isused to model the water in PCCWST which is suitable forfluid-structure interaction analysis [3 4 9 10] In order toreduce the calculation cost the shield building wall roof and

Science and Technology of Nuclear Installations 3

Table 3 The modal analysis results of six different water levels

Case Water level Volume Modal frequency1 2 3 sdot sdot sdot 7 sdot sdot sdot 9 sdot sdot sdot 13

I 86 3000 (100) 39115 58398 64290 92597 11683 14412II 71 2400 (80) 40273 58398 64290 96010 11870 14562III 58 1800 (60) 41096 58398 64290 10017 12160 14711IV 47 1200 (40) 41610 58398 64290 10129 12250 14796V 32 600 (20) 42130 58399 64290 10402 12250 14965VI 0 0 (0) 42543 58399 64291 10706 12250 15217

Z

X

Y

Figure 2 The shield building mesh viewed by partial section

PCCWST are modeled by shell element Shell63 rather thansolid element The mesh of shield building is illustrated inFigure 2 with a partial section view

For boundary condition atmospheric pressure is appliedto the free water surface The fluid-structure coupling pres-sure boundary condition is defined at the PCCWST wall andbottomThe contact nodes of water and structure are mergedto maintain identical displacement which assure the waterand the structure will not separate or penetrate

Formodal analysis the boundary condition for the analy-sis is that all the nodes of the shell elements at the foundationlevel are fixed that is the displacements translational orrotational were set to zero Unsymmetrical algorithm whichis specifically useful for fluid-structure modal problem isadopted for modal analysis by ANSYS For transient anal-ysis the north-south direction time acceleration history ofEl Centro wave (035 g) is applied to the shield buildingNewmarkrsquos numerical method was used for the structuralresponse of shield building in the time domain analysisRayleigh damping was also used to simulate the structuraldamping The damping coefficient was assumed as 7

The size of mesh is a key factor for the accuracy of FEresults While pursuing higher accuracy the computationalcost has to be well evaluated In this study 3 sizes of elementare adopted 10 15 and 20mwith error of 0 209and 018

subjecting to the maximum seismic acceleration response ofshield building top (Point 1 in Figure 1)Therefore the elementsize 10m is chosen for the final computation with 32224nodes and 3320 elements

4 Results and Discussion

41 Modal Analysis This paper focused on the influenceon dynamic response of shield building of different waterlevels in PCCWST considering the FSI phenomenon Sixcases of water levels shown in Figure 3 corresponding to100 80 60 40 20 and 0 of operational waterlevel were selected to be analyzed In the modal analysisthere were totally 40 modal shapes that have been extractedAccording to characteristics of cylindrical building modalshape some significant modal shapes and correspondingmodal frequencies were listed in Table 3 and Figure 4

As shown in Figure 4 in which the color represented the119883 direction displacement the first modal frequency is thebendingmode of the shield building moreover the followingtwo modes are the buckling of the shield building The 7thmodal shape is the local deformation of shield building roofwhile the 9th modal is the bending of PCCWST The 13thmodal shape is similar to the 7th modal shape however witha considerable bending of shield building

According to Table 3 the first modal frequencies increaseslightly from Case I to Case VI This can be explainedsketchily by the following equation

119891 =1

2120587

radic119870

119872 (5)

We assume the whole shield building as a single degreeof freedom cantilever beam with ldquosolid waterrdquo attached tothe top The floating water can hardly change the structurestiffness 119870 however the decreasing water will reduce thetotal mass of structure 119872 which leads to the increasingof fundamental frequency 119891 The frequency changes are sosmall that the mass difference of six cases is relatively smallcompared with the total mass of shield building Anotherfinding is that the 2nd and 3rd modal frequencies are almostthe same for different water level cases This is because thehigher modes are the local deformation of shield buildingwhich can be proved that the displacement of PCCWST isalmost zero with a uniform color distribution in its modalshape For 7th 9th and 13th modal frequencies increasefrom Case I to Case VI with the similar trend with first

4 Science and Technology of Nuclear Installations

(a) (b)

(c) (d)

(e) (f)

Figure 3 Water levels ranged from Case I to Case VI

modal shape This means the mass of water influences thelocal structures consisted of PCCWST and shield buildingroof

42 Transient Analysis This paper studied the influence ofvarious water levels on the safety and integrity of shield build-ing subjecting to seismic loading El Centro acceleration timehistories with acceleration amplitude 035 g were applied tothe shield building Figure 5 shows the north-south directionof El Centro wave which was used as the ground accelerationtime history in this paper

Figure 6(a) illustrated Case I distribution of von Misesstress at the time 258 s the time when maximum stressoccurs during the whole time history The maximum vonMises stress for six cases was 921 913 804 701 680 and628MPa respectively all occurring at the joint of shieldbuilding roof and inside wallThemaximum vonMises stressfor all six cases is below the 276MPa yield strength givenby AP1000 DCD However due to the effect of air inletthe maximum values happened around the air inlet cornerrather than on the symmetry plane of shield building whichis the results of stress concentration seen from Figure 6(a)Although along thewhole time history the overallmaximum

stress happened at this special location at certain timemaximum stress can also take place at the bottom of shieldbuilding outside wall or at the bottom of PCCWST Figures6(b) and 6(c) are the typical states of stress distributionillustrating these states

The acceleration response is a very significant indexreflecting the structure motion In this study Point 1 atthe top of the building was chosen to reveal the seismicresponse because the response of this point is relativelylarge Time history curve is an effective way of showing thetransient response however the overlapping curves are hardto distinguish from each other when comparing differentcurves In this paper the upper and lower envelopes of timehistory curve are used to show the seismic response of thestructure because we focus more on the maximum valueThe envelopes of acceleration time history at Point 1 fordifferent cases are illustrated in Figure 7 The accelerationresponses are similar for all six cases especially at the 25 and10 seconds with extremely high peaks corresponding to theseismic loading Obviously in Figure 7 the maximum andaverage acceleration response of case I is the largest among sixcasesThismeans the acceleration response of shield buildingtop is decreasing with the water level reducing However

Science and Technology of Nuclear Installations 5

Z

XY

MX

MN

0

0117Eminus6

0233Eminus6

0350Eminus6

0466Eminus6

0583minus6

0700Eminus6

0816Eminus6

0933Eminus6

0105Eminus5

(a) The fundamental mode shape

Z

XY

minus0151Eminus3

minus0109Eminus3

minus0677Eminus4

minus0263Eminus4

0152Eminus4

0566Eminus4

0981Eminus4

0140Eminus3

0181Eminus3

0222Eminus3

MXMN

(b) The 2nd mode shape

Z

XY

minus0454Eminus3

minus0353Eminus3

minus0252Eminus3

minus0151Eminus3

minus0505Eminus4

0505Eminus4

0151Eminus3

0252Eminus3

0353Eminus3

0454Eminus3

MXMN

(c) The 3rd mode shape

Z

XY

minus0170Eminus6

minus0123Eminus6

minus0760Eminus7

minus0289Eminus7

0182Eminus7

0653Eminus7

0112Eminus6

0160Eminus6

0207Eminus6

0254Eminus6

MX

MN

(d) The 7th mode shape

Z

XY

minus0418Eminus6

minus0325Eminus6

minus0232Eminus6

minus0129Eminus6

minus0464Eminus7

0464Eminus7

0139Eminus6

0232Eminus6

0325Eminus6

0418Eminus6

MXMN

(e) The 9th mode shape

Z

XY

minus0329Eminus6

minus0258Eminus6

minus0186Eminus6

minus0114Eminus6

minus0421Eminus7

0294Eminus7

0101Eminus6

0173Eminus6

0245Eminus6

0317Eminus6

MX

MN

(f) The 13th mode shape

Figure 4 The mode shape of shield building

response of Case VI has more considerable amplitude at the15 secondsThis is probably caused by the deformation of theshield building roof corresponding to the highermodal shapesuch as 7th 9th and 13th The corresponding displacementresponses of Point 1 are illustrated in Figure 8 A similarresponse as the acceleration curve was obtained with the

maximum displacement of 256 246 239 226 216 and206 cm for six cases respectively

The maximum von Mises stress emerges at the jointof shield building wall and roof around the air intakeConsequently von Mises stress of the two selected points(Points 2 and 3 in Figure 1) around air intake is plotted in

6 Science and Technology of Nuclear Installations

NS

Gro

und

acce

lera

tion

(G)

Time (t)

02

01

00

minus01

minus02

0 10 20

Figure 5 The El Centro wave time history with 035 g

Z

XY

MX

MN

93421

0103E+07

0205E+07

0308E+07

0410E+07

0515E+07

0614E+07

0717E+07

0819E+07

0921E+07

(a) 258 seconds

265901

114610

226562

338513

450464

562415

674367

786318

898269

Z

XY

MX

MX0101E+07

(b) 264 seconds

Z

XY

MN

MX

353981

726279

0145E+07

0217E+07

0289E+07

0362E+07

0434E+07

0506E+07

0579E+07

0651E+07

(c) 26 seconds

Figure 6 The von Mises stress distribution of shield building of Case I

Table 4 The maximum transient data and the relative difference compared with Case I

Response Displacement (cm) Acceleration (ms2) von Mises stress (MPa)Position Point 1 Point 1 Point 2 Point 3Case I 2563 (0) 13410 (0) 6507 (0) 8563 (0)Case II 2469 (366) 12580 (618) 6270 (364) 8265 (348)Case III 2391 (671) 11599 (1351) 5554 (1460) 7330 (1440)Case IV 2269 (1147) 10777 (1963) 5096 (2168) 4946 (4224)Case V 2163 (1561) 9916 (2605) 4801 (2621) 4469 (4781)Case VI 2060 (1963) 9194 (3142) 4399 (3240) 4001 (5328)

Science and Technology of Nuclear Installations 7En

velo

pes o

f acc

eler

atio

n re

spon

se(m

s2)

Time (s)

14121086420

minus2minus4minus6minus8minus10minus12minus14minus16minus18

0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Figure 7 The envelopes of acceleration time history at Point 1

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Enve

lope

s of d

ispla

cem

ent r

espo

nse (

cm)

30

25

20

15

10

00

05

minus05

minus10

minus15

minus20

minus25

Figure 8 The envelopes of displacement time history at Point 1

Figures 9 and 10The twofigures show similar curveswith dif-ferent amplitudes Table 4 concludes the maximum value ofseismic response to different water levels in PCCWST and therelative difference compared with Case I It can be seen thatnearly all response values decreased with the reduced watervolume The decreased responses are basically following alinear pattern with the decreased water volume especially forthe displacement response acceleration response and stressresponse at Point 2 The results show that PCCWST withwater draining up is much safer than that with an operationalwater level The change is relatively large with a displacementreduction 196 an acceleration reduction 314 and a stressreduction 32 at Point 2 However the reduction of stressresponse at Point 3 is not linear which may be caused by thestress concentration

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Upp

er en

velo

pes o

f von

Mise

s stre

ss (M

Pa)

8

6

4

2

0

Figure 9 The upper envelopes of von Mises stress time history atPoint 3

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Upp

er en

velo

pes o

f von

Mise

s stre

ss (M

Pa) 7

6

5

4

3

2

1

0

Figure 10 The upper envelopes of von Mises stress time history atPoint 2

5 Conclusions

The structural modal and seismic response of shield buildinghave been investigated considering fluid-structure inter-action for different water levels The modal results showthe reduction of water level will increase the fundamentalfrequency of shield building as well as the modal frequencyof shape modal corresponding to the local deformation ofshield building roof and PCCWST For higher order ofmodal themodal frequency is hardly influenced by the waterlevel However the influence of water level is relatively smallbecause the water mass only takes up a very small proportionof shield building For seismic response of shield buildingthe maximum acceleration of shield building top for Case VI

8 Science and Technology of Nuclear Installations

is about 31 less than that of Case I The maximum dis-placement of the same position for Case VI is about 1963less than that of Case I The von Mises stress at differentpoint around the air intake for Case VI is about 32 and53 less than that of Case I All responses are inclining withthe reduction of water volume although the decreased stressresponses at air inlet corner are not following a linear patternwith the decreased water volume The results indicated thedecreasing water level will reduce the structure responsewhich means even when water in the PCCWST is drainingto empty the shield building can still stand the earthquakewith enough margin

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

The project was sponsored by National Science and Technol-ogy Major Project of the Ministry of Science and Technologyof China (2012ZX06004-012-004)

References

[1] C Zhao J Chen and Q Xu ldquoDynamic analysis of AP1000shield building for various elevations and shapes of air intakesconsidering FSI effects subjected to seismic loadingrdquo Progress inNuclear Energy vol 74 pp 44ndash52 2014

[2] M Jolie M M Hassan and A A El Damatty ldquoAssessmentof current design procedures for conical tanks under seismicloadingrdquo Canadian Journal of Civil Engineering vol 40 no 12pp 1151ndash1163 2013

[3] R Livaoglu and A Dogangun ldquoSimplified seismic analysisprocedures for elevated tanks considering fluid-structure-soilinteractionrdquo Journal of Fluids and Structures vol 22 no 3 pp421ndash439 2006

[4] M Moslemi M R Kianoush and W Pogorzelski ldquoSeismicresponse of liquid-filled elevated tanksrdquo Engineering Structuresvol 33 no 6 pp 2074ndash2084 2011

[5] M Masoudi S Eshghi and M Ghafory-Ashtiany ldquoEvaluationof response modification factor (R) of elevated concrete tanksrdquoEngineering Structures vol 39 pp 199ndash209 2012

[6] D-S Lee M-L Liu T-C Hung C-H Tsai and Y-TChen ldquoOptimal structural analysis with associated passiveheat removal for AP1000 shield buildingrdquo Applied ThermalEngineering vol 50 no 1 pp 207ndash216 2013

[7] Y Choi S Lim B-H Ko et al ldquoDynamic characteristicsidentification of reactor internals in SMART considering fluid-structure interactionrdquoNuclear Engineering and Design vol 255pp 202ndash211 2013

[8] WestinghouseThe AP1000 European DCD UKAP1000 SafetySecurity and Environmental Report p 51ndash53

[9] N Hosseinzadeh H Kazem M Ghahremannejad E Ahmadiand N Kazem ldquoComparison of API650-2008 provisions withFEM analyses for seismic assessment of existing steel oil storagetanksrdquo Journal of Loss Prevention in the Process Industries vol26 no 4 pp 666ndash675 2013

[10] H Sezen R Livaoglu and A Dogangun ldquoDynamic analysisand seismic performance evaluation of above-ground liquid-containing tanksrdquo Engineering Structures vol 30 no 3 pp 794ndash803 2008

TribologyAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

FuelsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofPetroleum Engineering

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Industrial EngineeringJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Power ElectronicsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

CombustionJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Renewable Energy

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

StructuresJournal of

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nuclear InstallationsScience and Technology of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Solar EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Wind EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nuclear EnergyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

High Energy PhysicsAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Page 2: Research Article AP1000 Shield Building Dynamic Response ...downloads.hindawi.com/journals/stni/2015/840507.pdf · AP1000 Shield Building Dynamic Response for Different Water ...

2 Science and Technology of Nuclear Installations

influence the dynamic behavior of shield building underseismic loading In current study a finite element modelof AP1000 shield building was established and the differentwater levels were discussed for both modal and transientanalysis The FEM results may also provide a reference fordesign of the AP1000 and CAP1400 in the future

2 Theory of Fluid-Structure Interaction

For a structural system the governing equation derived fromfinite element formulation can be obtained as follows

119872 + 119862 + 119870119906 = 119865 (1)

where119872 119862 and 119870 are mass damping and stiffness matrixfor structure and 119906 is the displacement vector 119865 is the totalforce applied by other systems However for fluid-structureinteraction problem the FSI can be expressed by coupling thegoverning equation of the structure and fluid at the interfaceThe interface force caused by the fluid pressure at the interfaceis transferred to the structure So the 119865 of equation can beextended to

119865 = 1198651015840+ 119865119901 (2)

where 119865119901 is the integration of fluid pressure on the fluid-structure interface and 1198651015840 is the external force excluding 119865119901The fluid pressure field can be derived from the followingequation assuming the fluid as incompressible and inviscid

1

119888

1205972119875

1205971199052minus nabla2119875 = 0 (3)

where 119888 is the fluid sound speed and 119905 is the time Thedetailed formula deduction can refer to the work by Choiet al [7] The final matrix equation involves nonsymmetricand stiffness matrix The eigenvalues of the coupled problemcan be obtained with unsymmetrical algorithm for modalanalysis by ANSYS

For FEM transient analysis the Newmark algorithm is aneffective way of solving the structural response InNewmarkrsquosalgorithm Rayleigh damping is adopted for defining thedamping denoted as

119862 = 120572119872 + 120573119870

120572 =212058512059611205962

1205961+ 1205962

120573 =2120585

1205961+ 1205962

(4)

where 120572 and 120573 are the mass and stiffness proportionalRayleigh damping coefficient respectively The 120585 120596

1 and 120596

2

are damping ratio the first and second undamped naturalfrequency of the structure According to the AP1000 DCD[8] the damping ratio 7 is adopted Inmaterials science andengineering the von Mises yield criterion is used to predictyielding of materials A material is said to start yielding whenits von Mises stress reaches a critical value known as theyield strength In this paper the yield strength of reinforcedconcrete 276MPa is used according to the AP1000 DCD

P1

P2 P3

Z

XY

Figure 1 The geometry of shield building

Table 1 The geometry of shield building

Geometry Dimension(m)Height Diameter Thickness

Shield building 71 442 09PCCWST 58115 90271 05Water 86 90271 mdash

Table 2 The material properties

Material Density(kgm3)

Elastic module(GPa) Poisson ratio

Uniform reinforcedConcrete 2300 335 02

Water 1000 mdash mdash

3 Structural Assessment of AP1000 PCCWSTby FEM Model

31 AP1000 PCS The main part of the structure for shieldbuilding includes shield building wall with 16 rectangularcooling air intakes the shield building roof PCCWST andwater shown as Figure 1 The uniform reinforced concretemodel is adopted to simulate shield building The materialproperties and geometric conditions are shown in Tables1 and 2 In this paper six different water levels (Table 3)corresponding to the 100 80 60 40 20 and 0of operational water volume are analyzed to figure out thestructure assessment of water level decreasing owing to thewater draining in accident scenario Both modal analysis andtransient analysis are carried out for six different water levels

32 FEMModel The pressure-based fluid element Fluid30 isused to model the water in PCCWST which is suitable forfluid-structure interaction analysis [3 4 9 10] In order toreduce the calculation cost the shield building wall roof and

Science and Technology of Nuclear Installations 3

Table 3 The modal analysis results of six different water levels

Case Water level Volume Modal frequency1 2 3 sdot sdot sdot 7 sdot sdot sdot 9 sdot sdot sdot 13

I 86 3000 (100) 39115 58398 64290 92597 11683 14412II 71 2400 (80) 40273 58398 64290 96010 11870 14562III 58 1800 (60) 41096 58398 64290 10017 12160 14711IV 47 1200 (40) 41610 58398 64290 10129 12250 14796V 32 600 (20) 42130 58399 64290 10402 12250 14965VI 0 0 (0) 42543 58399 64291 10706 12250 15217

Z

X

Y

Figure 2 The shield building mesh viewed by partial section

PCCWST are modeled by shell element Shell63 rather thansolid element The mesh of shield building is illustrated inFigure 2 with a partial section view

For boundary condition atmospheric pressure is appliedto the free water surface The fluid-structure coupling pres-sure boundary condition is defined at the PCCWST wall andbottomThe contact nodes of water and structure are mergedto maintain identical displacement which assure the waterand the structure will not separate or penetrate

Formodal analysis the boundary condition for the analy-sis is that all the nodes of the shell elements at the foundationlevel are fixed that is the displacements translational orrotational were set to zero Unsymmetrical algorithm whichis specifically useful for fluid-structure modal problem isadopted for modal analysis by ANSYS For transient anal-ysis the north-south direction time acceleration history ofEl Centro wave (035 g) is applied to the shield buildingNewmarkrsquos numerical method was used for the structuralresponse of shield building in the time domain analysisRayleigh damping was also used to simulate the structuraldamping The damping coefficient was assumed as 7

The size of mesh is a key factor for the accuracy of FEresults While pursuing higher accuracy the computationalcost has to be well evaluated In this study 3 sizes of elementare adopted 10 15 and 20mwith error of 0 209and 018

subjecting to the maximum seismic acceleration response ofshield building top (Point 1 in Figure 1)Therefore the elementsize 10m is chosen for the final computation with 32224nodes and 3320 elements

4 Results and Discussion

41 Modal Analysis This paper focused on the influenceon dynamic response of shield building of different waterlevels in PCCWST considering the FSI phenomenon Sixcases of water levels shown in Figure 3 corresponding to100 80 60 40 20 and 0 of operational waterlevel were selected to be analyzed In the modal analysisthere were totally 40 modal shapes that have been extractedAccording to characteristics of cylindrical building modalshape some significant modal shapes and correspondingmodal frequencies were listed in Table 3 and Figure 4

As shown in Figure 4 in which the color represented the119883 direction displacement the first modal frequency is thebendingmode of the shield building moreover the followingtwo modes are the buckling of the shield building The 7thmodal shape is the local deformation of shield building roofwhile the 9th modal is the bending of PCCWST The 13thmodal shape is similar to the 7th modal shape however witha considerable bending of shield building

According to Table 3 the first modal frequencies increaseslightly from Case I to Case VI This can be explainedsketchily by the following equation

119891 =1

2120587

radic119870

119872 (5)

We assume the whole shield building as a single degreeof freedom cantilever beam with ldquosolid waterrdquo attached tothe top The floating water can hardly change the structurestiffness 119870 however the decreasing water will reduce thetotal mass of structure 119872 which leads to the increasingof fundamental frequency 119891 The frequency changes are sosmall that the mass difference of six cases is relatively smallcompared with the total mass of shield building Anotherfinding is that the 2nd and 3rd modal frequencies are almostthe same for different water level cases This is because thehigher modes are the local deformation of shield buildingwhich can be proved that the displacement of PCCWST isalmost zero with a uniform color distribution in its modalshape For 7th 9th and 13th modal frequencies increasefrom Case I to Case VI with the similar trend with first

4 Science and Technology of Nuclear Installations

(a) (b)

(c) (d)

(e) (f)

Figure 3 Water levels ranged from Case I to Case VI

modal shape This means the mass of water influences thelocal structures consisted of PCCWST and shield buildingroof

42 Transient Analysis This paper studied the influence ofvarious water levels on the safety and integrity of shield build-ing subjecting to seismic loading El Centro acceleration timehistories with acceleration amplitude 035 g were applied tothe shield building Figure 5 shows the north-south directionof El Centro wave which was used as the ground accelerationtime history in this paper

Figure 6(a) illustrated Case I distribution of von Misesstress at the time 258 s the time when maximum stressoccurs during the whole time history The maximum vonMises stress for six cases was 921 913 804 701 680 and628MPa respectively all occurring at the joint of shieldbuilding roof and inside wallThemaximum vonMises stressfor all six cases is below the 276MPa yield strength givenby AP1000 DCD However due to the effect of air inletthe maximum values happened around the air inlet cornerrather than on the symmetry plane of shield building whichis the results of stress concentration seen from Figure 6(a)Although along thewhole time history the overallmaximum

stress happened at this special location at certain timemaximum stress can also take place at the bottom of shieldbuilding outside wall or at the bottom of PCCWST Figures6(b) and 6(c) are the typical states of stress distributionillustrating these states

The acceleration response is a very significant indexreflecting the structure motion In this study Point 1 atthe top of the building was chosen to reveal the seismicresponse because the response of this point is relativelylarge Time history curve is an effective way of showing thetransient response however the overlapping curves are hardto distinguish from each other when comparing differentcurves In this paper the upper and lower envelopes of timehistory curve are used to show the seismic response of thestructure because we focus more on the maximum valueThe envelopes of acceleration time history at Point 1 fordifferent cases are illustrated in Figure 7 The accelerationresponses are similar for all six cases especially at the 25 and10 seconds with extremely high peaks corresponding to theseismic loading Obviously in Figure 7 the maximum andaverage acceleration response of case I is the largest among sixcasesThismeans the acceleration response of shield buildingtop is decreasing with the water level reducing However

Science and Technology of Nuclear Installations 5

Z

XY

MX

MN

0

0117Eminus6

0233Eminus6

0350Eminus6

0466Eminus6

0583minus6

0700Eminus6

0816Eminus6

0933Eminus6

0105Eminus5

(a) The fundamental mode shape

Z

XY

minus0151Eminus3

minus0109Eminus3

minus0677Eminus4

minus0263Eminus4

0152Eminus4

0566Eminus4

0981Eminus4

0140Eminus3

0181Eminus3

0222Eminus3

MXMN

(b) The 2nd mode shape

Z

XY

minus0454Eminus3

minus0353Eminus3

minus0252Eminus3

minus0151Eminus3

minus0505Eminus4

0505Eminus4

0151Eminus3

0252Eminus3

0353Eminus3

0454Eminus3

MXMN

(c) The 3rd mode shape

Z

XY

minus0170Eminus6

minus0123Eminus6

minus0760Eminus7

minus0289Eminus7

0182Eminus7

0653Eminus7

0112Eminus6

0160Eminus6

0207Eminus6

0254Eminus6

MX

MN

(d) The 7th mode shape

Z

XY

minus0418Eminus6

minus0325Eminus6

minus0232Eminus6

minus0129Eminus6

minus0464Eminus7

0464Eminus7

0139Eminus6

0232Eminus6

0325Eminus6

0418Eminus6

MXMN

(e) The 9th mode shape

Z

XY

minus0329Eminus6

minus0258Eminus6

minus0186Eminus6

minus0114Eminus6

minus0421Eminus7

0294Eminus7

0101Eminus6

0173Eminus6

0245Eminus6

0317Eminus6

MX

MN

(f) The 13th mode shape

Figure 4 The mode shape of shield building

response of Case VI has more considerable amplitude at the15 secondsThis is probably caused by the deformation of theshield building roof corresponding to the highermodal shapesuch as 7th 9th and 13th The corresponding displacementresponses of Point 1 are illustrated in Figure 8 A similarresponse as the acceleration curve was obtained with the

maximum displacement of 256 246 239 226 216 and206 cm for six cases respectively

The maximum von Mises stress emerges at the jointof shield building wall and roof around the air intakeConsequently von Mises stress of the two selected points(Points 2 and 3 in Figure 1) around air intake is plotted in

6 Science and Technology of Nuclear Installations

NS

Gro

und

acce

lera

tion

(G)

Time (t)

02

01

00

minus01

minus02

0 10 20

Figure 5 The El Centro wave time history with 035 g

Z

XY

MX

MN

93421

0103E+07

0205E+07

0308E+07

0410E+07

0515E+07

0614E+07

0717E+07

0819E+07

0921E+07

(a) 258 seconds

265901

114610

226562

338513

450464

562415

674367

786318

898269

Z

XY

MX

MX0101E+07

(b) 264 seconds

Z

XY

MN

MX

353981

726279

0145E+07

0217E+07

0289E+07

0362E+07

0434E+07

0506E+07

0579E+07

0651E+07

(c) 26 seconds

Figure 6 The von Mises stress distribution of shield building of Case I

Table 4 The maximum transient data and the relative difference compared with Case I

Response Displacement (cm) Acceleration (ms2) von Mises stress (MPa)Position Point 1 Point 1 Point 2 Point 3Case I 2563 (0) 13410 (0) 6507 (0) 8563 (0)Case II 2469 (366) 12580 (618) 6270 (364) 8265 (348)Case III 2391 (671) 11599 (1351) 5554 (1460) 7330 (1440)Case IV 2269 (1147) 10777 (1963) 5096 (2168) 4946 (4224)Case V 2163 (1561) 9916 (2605) 4801 (2621) 4469 (4781)Case VI 2060 (1963) 9194 (3142) 4399 (3240) 4001 (5328)

Science and Technology of Nuclear Installations 7En

velo

pes o

f acc

eler

atio

n re

spon

se(m

s2)

Time (s)

14121086420

minus2minus4minus6minus8minus10minus12minus14minus16minus18

0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Figure 7 The envelopes of acceleration time history at Point 1

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Enve

lope

s of d

ispla

cem

ent r

espo

nse (

cm)

30

25

20

15

10

00

05

minus05

minus10

minus15

minus20

minus25

Figure 8 The envelopes of displacement time history at Point 1

Figures 9 and 10The twofigures show similar curveswith dif-ferent amplitudes Table 4 concludes the maximum value ofseismic response to different water levels in PCCWST and therelative difference compared with Case I It can be seen thatnearly all response values decreased with the reduced watervolume The decreased responses are basically following alinear pattern with the decreased water volume especially forthe displacement response acceleration response and stressresponse at Point 2 The results show that PCCWST withwater draining up is much safer than that with an operationalwater level The change is relatively large with a displacementreduction 196 an acceleration reduction 314 and a stressreduction 32 at Point 2 However the reduction of stressresponse at Point 3 is not linear which may be caused by thestress concentration

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Upp

er en

velo

pes o

f von

Mise

s stre

ss (M

Pa)

8

6

4

2

0

Figure 9 The upper envelopes of von Mises stress time history atPoint 3

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Upp

er en

velo

pes o

f von

Mise

s stre

ss (M

Pa) 7

6

5

4

3

2

1

0

Figure 10 The upper envelopes of von Mises stress time history atPoint 2

5 Conclusions

The structural modal and seismic response of shield buildinghave been investigated considering fluid-structure inter-action for different water levels The modal results showthe reduction of water level will increase the fundamentalfrequency of shield building as well as the modal frequencyof shape modal corresponding to the local deformation ofshield building roof and PCCWST For higher order ofmodal themodal frequency is hardly influenced by the waterlevel However the influence of water level is relatively smallbecause the water mass only takes up a very small proportionof shield building For seismic response of shield buildingthe maximum acceleration of shield building top for Case VI

8 Science and Technology of Nuclear Installations

is about 31 less than that of Case I The maximum dis-placement of the same position for Case VI is about 1963less than that of Case I The von Mises stress at differentpoint around the air intake for Case VI is about 32 and53 less than that of Case I All responses are inclining withthe reduction of water volume although the decreased stressresponses at air inlet corner are not following a linear patternwith the decreased water volume The results indicated thedecreasing water level will reduce the structure responsewhich means even when water in the PCCWST is drainingto empty the shield building can still stand the earthquakewith enough margin

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

The project was sponsored by National Science and Technol-ogy Major Project of the Ministry of Science and Technologyof China (2012ZX06004-012-004)

References

[1] C Zhao J Chen and Q Xu ldquoDynamic analysis of AP1000shield building for various elevations and shapes of air intakesconsidering FSI effects subjected to seismic loadingrdquo Progress inNuclear Energy vol 74 pp 44ndash52 2014

[2] M Jolie M M Hassan and A A El Damatty ldquoAssessmentof current design procedures for conical tanks under seismicloadingrdquo Canadian Journal of Civil Engineering vol 40 no 12pp 1151ndash1163 2013

[3] R Livaoglu and A Dogangun ldquoSimplified seismic analysisprocedures for elevated tanks considering fluid-structure-soilinteractionrdquo Journal of Fluids and Structures vol 22 no 3 pp421ndash439 2006

[4] M Moslemi M R Kianoush and W Pogorzelski ldquoSeismicresponse of liquid-filled elevated tanksrdquo Engineering Structuresvol 33 no 6 pp 2074ndash2084 2011

[5] M Masoudi S Eshghi and M Ghafory-Ashtiany ldquoEvaluationof response modification factor (R) of elevated concrete tanksrdquoEngineering Structures vol 39 pp 199ndash209 2012

[6] D-S Lee M-L Liu T-C Hung C-H Tsai and Y-TChen ldquoOptimal structural analysis with associated passiveheat removal for AP1000 shield buildingrdquo Applied ThermalEngineering vol 50 no 1 pp 207ndash216 2013

[7] Y Choi S Lim B-H Ko et al ldquoDynamic characteristicsidentification of reactor internals in SMART considering fluid-structure interactionrdquoNuclear Engineering and Design vol 255pp 202ndash211 2013

[8] WestinghouseThe AP1000 European DCD UKAP1000 SafetySecurity and Environmental Report p 51ndash53

[9] N Hosseinzadeh H Kazem M Ghahremannejad E Ahmadiand N Kazem ldquoComparison of API650-2008 provisions withFEM analyses for seismic assessment of existing steel oil storagetanksrdquo Journal of Loss Prevention in the Process Industries vol26 no 4 pp 666ndash675 2013

[10] H Sezen R Livaoglu and A Dogangun ldquoDynamic analysisand seismic performance evaluation of above-ground liquid-containing tanksrdquo Engineering Structures vol 30 no 3 pp 794ndash803 2008

TribologyAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

FuelsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofPetroleum Engineering

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Industrial EngineeringJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Power ElectronicsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

CombustionJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Renewable Energy

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

StructuresJournal of

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nuclear InstallationsScience and Technology of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Solar EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Wind EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nuclear EnergyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

High Energy PhysicsAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Page 3: Research Article AP1000 Shield Building Dynamic Response ...downloads.hindawi.com/journals/stni/2015/840507.pdf · AP1000 Shield Building Dynamic Response for Different Water ...

Science and Technology of Nuclear Installations 3

Table 3 The modal analysis results of six different water levels

Case Water level Volume Modal frequency1 2 3 sdot sdot sdot 7 sdot sdot sdot 9 sdot sdot sdot 13

I 86 3000 (100) 39115 58398 64290 92597 11683 14412II 71 2400 (80) 40273 58398 64290 96010 11870 14562III 58 1800 (60) 41096 58398 64290 10017 12160 14711IV 47 1200 (40) 41610 58398 64290 10129 12250 14796V 32 600 (20) 42130 58399 64290 10402 12250 14965VI 0 0 (0) 42543 58399 64291 10706 12250 15217

Z

X

Y

Figure 2 The shield building mesh viewed by partial section

PCCWST are modeled by shell element Shell63 rather thansolid element The mesh of shield building is illustrated inFigure 2 with a partial section view

For boundary condition atmospheric pressure is appliedto the free water surface The fluid-structure coupling pres-sure boundary condition is defined at the PCCWST wall andbottomThe contact nodes of water and structure are mergedto maintain identical displacement which assure the waterand the structure will not separate or penetrate

Formodal analysis the boundary condition for the analy-sis is that all the nodes of the shell elements at the foundationlevel are fixed that is the displacements translational orrotational were set to zero Unsymmetrical algorithm whichis specifically useful for fluid-structure modal problem isadopted for modal analysis by ANSYS For transient anal-ysis the north-south direction time acceleration history ofEl Centro wave (035 g) is applied to the shield buildingNewmarkrsquos numerical method was used for the structuralresponse of shield building in the time domain analysisRayleigh damping was also used to simulate the structuraldamping The damping coefficient was assumed as 7

The size of mesh is a key factor for the accuracy of FEresults While pursuing higher accuracy the computationalcost has to be well evaluated In this study 3 sizes of elementare adopted 10 15 and 20mwith error of 0 209and 018

subjecting to the maximum seismic acceleration response ofshield building top (Point 1 in Figure 1)Therefore the elementsize 10m is chosen for the final computation with 32224nodes and 3320 elements

4 Results and Discussion

41 Modal Analysis This paper focused on the influenceon dynamic response of shield building of different waterlevels in PCCWST considering the FSI phenomenon Sixcases of water levels shown in Figure 3 corresponding to100 80 60 40 20 and 0 of operational waterlevel were selected to be analyzed In the modal analysisthere were totally 40 modal shapes that have been extractedAccording to characteristics of cylindrical building modalshape some significant modal shapes and correspondingmodal frequencies were listed in Table 3 and Figure 4

As shown in Figure 4 in which the color represented the119883 direction displacement the first modal frequency is thebendingmode of the shield building moreover the followingtwo modes are the buckling of the shield building The 7thmodal shape is the local deformation of shield building roofwhile the 9th modal is the bending of PCCWST The 13thmodal shape is similar to the 7th modal shape however witha considerable bending of shield building

According to Table 3 the first modal frequencies increaseslightly from Case I to Case VI This can be explainedsketchily by the following equation

119891 =1

2120587

radic119870

119872 (5)

We assume the whole shield building as a single degreeof freedom cantilever beam with ldquosolid waterrdquo attached tothe top The floating water can hardly change the structurestiffness 119870 however the decreasing water will reduce thetotal mass of structure 119872 which leads to the increasingof fundamental frequency 119891 The frequency changes are sosmall that the mass difference of six cases is relatively smallcompared with the total mass of shield building Anotherfinding is that the 2nd and 3rd modal frequencies are almostthe same for different water level cases This is because thehigher modes are the local deformation of shield buildingwhich can be proved that the displacement of PCCWST isalmost zero with a uniform color distribution in its modalshape For 7th 9th and 13th modal frequencies increasefrom Case I to Case VI with the similar trend with first

4 Science and Technology of Nuclear Installations

(a) (b)

(c) (d)

(e) (f)

Figure 3 Water levels ranged from Case I to Case VI

modal shape This means the mass of water influences thelocal structures consisted of PCCWST and shield buildingroof

42 Transient Analysis This paper studied the influence ofvarious water levels on the safety and integrity of shield build-ing subjecting to seismic loading El Centro acceleration timehistories with acceleration amplitude 035 g were applied tothe shield building Figure 5 shows the north-south directionof El Centro wave which was used as the ground accelerationtime history in this paper

Figure 6(a) illustrated Case I distribution of von Misesstress at the time 258 s the time when maximum stressoccurs during the whole time history The maximum vonMises stress for six cases was 921 913 804 701 680 and628MPa respectively all occurring at the joint of shieldbuilding roof and inside wallThemaximum vonMises stressfor all six cases is below the 276MPa yield strength givenby AP1000 DCD However due to the effect of air inletthe maximum values happened around the air inlet cornerrather than on the symmetry plane of shield building whichis the results of stress concentration seen from Figure 6(a)Although along thewhole time history the overallmaximum

stress happened at this special location at certain timemaximum stress can also take place at the bottom of shieldbuilding outside wall or at the bottom of PCCWST Figures6(b) and 6(c) are the typical states of stress distributionillustrating these states

The acceleration response is a very significant indexreflecting the structure motion In this study Point 1 atthe top of the building was chosen to reveal the seismicresponse because the response of this point is relativelylarge Time history curve is an effective way of showing thetransient response however the overlapping curves are hardto distinguish from each other when comparing differentcurves In this paper the upper and lower envelopes of timehistory curve are used to show the seismic response of thestructure because we focus more on the maximum valueThe envelopes of acceleration time history at Point 1 fordifferent cases are illustrated in Figure 7 The accelerationresponses are similar for all six cases especially at the 25 and10 seconds with extremely high peaks corresponding to theseismic loading Obviously in Figure 7 the maximum andaverage acceleration response of case I is the largest among sixcasesThismeans the acceleration response of shield buildingtop is decreasing with the water level reducing However

Science and Technology of Nuclear Installations 5

Z

XY

MX

MN

0

0117Eminus6

0233Eminus6

0350Eminus6

0466Eminus6

0583minus6

0700Eminus6

0816Eminus6

0933Eminus6

0105Eminus5

(a) The fundamental mode shape

Z

XY

minus0151Eminus3

minus0109Eminus3

minus0677Eminus4

minus0263Eminus4

0152Eminus4

0566Eminus4

0981Eminus4

0140Eminus3

0181Eminus3

0222Eminus3

MXMN

(b) The 2nd mode shape

Z

XY

minus0454Eminus3

minus0353Eminus3

minus0252Eminus3

minus0151Eminus3

minus0505Eminus4

0505Eminus4

0151Eminus3

0252Eminus3

0353Eminus3

0454Eminus3

MXMN

(c) The 3rd mode shape

Z

XY

minus0170Eminus6

minus0123Eminus6

minus0760Eminus7

minus0289Eminus7

0182Eminus7

0653Eminus7

0112Eminus6

0160Eminus6

0207Eminus6

0254Eminus6

MX

MN

(d) The 7th mode shape

Z

XY

minus0418Eminus6

minus0325Eminus6

minus0232Eminus6

minus0129Eminus6

minus0464Eminus7

0464Eminus7

0139Eminus6

0232Eminus6

0325Eminus6

0418Eminus6

MXMN

(e) The 9th mode shape

Z

XY

minus0329Eminus6

minus0258Eminus6

minus0186Eminus6

minus0114Eminus6

minus0421Eminus7

0294Eminus7

0101Eminus6

0173Eminus6

0245Eminus6

0317Eminus6

MX

MN

(f) The 13th mode shape

Figure 4 The mode shape of shield building

response of Case VI has more considerable amplitude at the15 secondsThis is probably caused by the deformation of theshield building roof corresponding to the highermodal shapesuch as 7th 9th and 13th The corresponding displacementresponses of Point 1 are illustrated in Figure 8 A similarresponse as the acceleration curve was obtained with the

maximum displacement of 256 246 239 226 216 and206 cm for six cases respectively

The maximum von Mises stress emerges at the jointof shield building wall and roof around the air intakeConsequently von Mises stress of the two selected points(Points 2 and 3 in Figure 1) around air intake is plotted in

6 Science and Technology of Nuclear Installations

NS

Gro

und

acce

lera

tion

(G)

Time (t)

02

01

00

minus01

minus02

0 10 20

Figure 5 The El Centro wave time history with 035 g

Z

XY

MX

MN

93421

0103E+07

0205E+07

0308E+07

0410E+07

0515E+07

0614E+07

0717E+07

0819E+07

0921E+07

(a) 258 seconds

265901

114610

226562

338513

450464

562415

674367

786318

898269

Z

XY

MX

MX0101E+07

(b) 264 seconds

Z

XY

MN

MX

353981

726279

0145E+07

0217E+07

0289E+07

0362E+07

0434E+07

0506E+07

0579E+07

0651E+07

(c) 26 seconds

Figure 6 The von Mises stress distribution of shield building of Case I

Table 4 The maximum transient data and the relative difference compared with Case I

Response Displacement (cm) Acceleration (ms2) von Mises stress (MPa)Position Point 1 Point 1 Point 2 Point 3Case I 2563 (0) 13410 (0) 6507 (0) 8563 (0)Case II 2469 (366) 12580 (618) 6270 (364) 8265 (348)Case III 2391 (671) 11599 (1351) 5554 (1460) 7330 (1440)Case IV 2269 (1147) 10777 (1963) 5096 (2168) 4946 (4224)Case V 2163 (1561) 9916 (2605) 4801 (2621) 4469 (4781)Case VI 2060 (1963) 9194 (3142) 4399 (3240) 4001 (5328)

Science and Technology of Nuclear Installations 7En

velo

pes o

f acc

eler

atio

n re

spon

se(m

s2)

Time (s)

14121086420

minus2minus4minus6minus8minus10minus12minus14minus16minus18

0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Figure 7 The envelopes of acceleration time history at Point 1

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Enve

lope

s of d

ispla

cem

ent r

espo

nse (

cm)

30

25

20

15

10

00

05

minus05

minus10

minus15

minus20

minus25

Figure 8 The envelopes of displacement time history at Point 1

Figures 9 and 10The twofigures show similar curveswith dif-ferent amplitudes Table 4 concludes the maximum value ofseismic response to different water levels in PCCWST and therelative difference compared with Case I It can be seen thatnearly all response values decreased with the reduced watervolume The decreased responses are basically following alinear pattern with the decreased water volume especially forthe displacement response acceleration response and stressresponse at Point 2 The results show that PCCWST withwater draining up is much safer than that with an operationalwater level The change is relatively large with a displacementreduction 196 an acceleration reduction 314 and a stressreduction 32 at Point 2 However the reduction of stressresponse at Point 3 is not linear which may be caused by thestress concentration

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Upp

er en

velo

pes o

f von

Mise

s stre

ss (M

Pa)

8

6

4

2

0

Figure 9 The upper envelopes of von Mises stress time history atPoint 3

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Upp

er en

velo

pes o

f von

Mise

s stre

ss (M

Pa) 7

6

5

4

3

2

1

0

Figure 10 The upper envelopes of von Mises stress time history atPoint 2

5 Conclusions

The structural modal and seismic response of shield buildinghave been investigated considering fluid-structure inter-action for different water levels The modal results showthe reduction of water level will increase the fundamentalfrequency of shield building as well as the modal frequencyof shape modal corresponding to the local deformation ofshield building roof and PCCWST For higher order ofmodal themodal frequency is hardly influenced by the waterlevel However the influence of water level is relatively smallbecause the water mass only takes up a very small proportionof shield building For seismic response of shield buildingthe maximum acceleration of shield building top for Case VI

8 Science and Technology of Nuclear Installations

is about 31 less than that of Case I The maximum dis-placement of the same position for Case VI is about 1963less than that of Case I The von Mises stress at differentpoint around the air intake for Case VI is about 32 and53 less than that of Case I All responses are inclining withthe reduction of water volume although the decreased stressresponses at air inlet corner are not following a linear patternwith the decreased water volume The results indicated thedecreasing water level will reduce the structure responsewhich means even when water in the PCCWST is drainingto empty the shield building can still stand the earthquakewith enough margin

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

The project was sponsored by National Science and Technol-ogy Major Project of the Ministry of Science and Technologyof China (2012ZX06004-012-004)

References

[1] C Zhao J Chen and Q Xu ldquoDynamic analysis of AP1000shield building for various elevations and shapes of air intakesconsidering FSI effects subjected to seismic loadingrdquo Progress inNuclear Energy vol 74 pp 44ndash52 2014

[2] M Jolie M M Hassan and A A El Damatty ldquoAssessmentof current design procedures for conical tanks under seismicloadingrdquo Canadian Journal of Civil Engineering vol 40 no 12pp 1151ndash1163 2013

[3] R Livaoglu and A Dogangun ldquoSimplified seismic analysisprocedures for elevated tanks considering fluid-structure-soilinteractionrdquo Journal of Fluids and Structures vol 22 no 3 pp421ndash439 2006

[4] M Moslemi M R Kianoush and W Pogorzelski ldquoSeismicresponse of liquid-filled elevated tanksrdquo Engineering Structuresvol 33 no 6 pp 2074ndash2084 2011

[5] M Masoudi S Eshghi and M Ghafory-Ashtiany ldquoEvaluationof response modification factor (R) of elevated concrete tanksrdquoEngineering Structures vol 39 pp 199ndash209 2012

[6] D-S Lee M-L Liu T-C Hung C-H Tsai and Y-TChen ldquoOptimal structural analysis with associated passiveheat removal for AP1000 shield buildingrdquo Applied ThermalEngineering vol 50 no 1 pp 207ndash216 2013

[7] Y Choi S Lim B-H Ko et al ldquoDynamic characteristicsidentification of reactor internals in SMART considering fluid-structure interactionrdquoNuclear Engineering and Design vol 255pp 202ndash211 2013

[8] WestinghouseThe AP1000 European DCD UKAP1000 SafetySecurity and Environmental Report p 51ndash53

[9] N Hosseinzadeh H Kazem M Ghahremannejad E Ahmadiand N Kazem ldquoComparison of API650-2008 provisions withFEM analyses for seismic assessment of existing steel oil storagetanksrdquo Journal of Loss Prevention in the Process Industries vol26 no 4 pp 666ndash675 2013

[10] H Sezen R Livaoglu and A Dogangun ldquoDynamic analysisand seismic performance evaluation of above-ground liquid-containing tanksrdquo Engineering Structures vol 30 no 3 pp 794ndash803 2008

TribologyAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

FuelsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofPetroleum Engineering

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Industrial EngineeringJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Power ElectronicsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

CombustionJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Renewable Energy

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

StructuresJournal of

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nuclear InstallationsScience and Technology of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Solar EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Wind EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nuclear EnergyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

High Energy PhysicsAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Page 4: Research Article AP1000 Shield Building Dynamic Response ...downloads.hindawi.com/journals/stni/2015/840507.pdf · AP1000 Shield Building Dynamic Response for Different Water ...

4 Science and Technology of Nuclear Installations

(a) (b)

(c) (d)

(e) (f)

Figure 3 Water levels ranged from Case I to Case VI

modal shape This means the mass of water influences thelocal structures consisted of PCCWST and shield buildingroof

42 Transient Analysis This paper studied the influence ofvarious water levels on the safety and integrity of shield build-ing subjecting to seismic loading El Centro acceleration timehistories with acceleration amplitude 035 g were applied tothe shield building Figure 5 shows the north-south directionof El Centro wave which was used as the ground accelerationtime history in this paper

Figure 6(a) illustrated Case I distribution of von Misesstress at the time 258 s the time when maximum stressoccurs during the whole time history The maximum vonMises stress for six cases was 921 913 804 701 680 and628MPa respectively all occurring at the joint of shieldbuilding roof and inside wallThemaximum vonMises stressfor all six cases is below the 276MPa yield strength givenby AP1000 DCD However due to the effect of air inletthe maximum values happened around the air inlet cornerrather than on the symmetry plane of shield building whichis the results of stress concentration seen from Figure 6(a)Although along thewhole time history the overallmaximum

stress happened at this special location at certain timemaximum stress can also take place at the bottom of shieldbuilding outside wall or at the bottom of PCCWST Figures6(b) and 6(c) are the typical states of stress distributionillustrating these states

The acceleration response is a very significant indexreflecting the structure motion In this study Point 1 atthe top of the building was chosen to reveal the seismicresponse because the response of this point is relativelylarge Time history curve is an effective way of showing thetransient response however the overlapping curves are hardto distinguish from each other when comparing differentcurves In this paper the upper and lower envelopes of timehistory curve are used to show the seismic response of thestructure because we focus more on the maximum valueThe envelopes of acceleration time history at Point 1 fordifferent cases are illustrated in Figure 7 The accelerationresponses are similar for all six cases especially at the 25 and10 seconds with extremely high peaks corresponding to theseismic loading Obviously in Figure 7 the maximum andaverage acceleration response of case I is the largest among sixcasesThismeans the acceleration response of shield buildingtop is decreasing with the water level reducing However

Science and Technology of Nuclear Installations 5

Z

XY

MX

MN

0

0117Eminus6

0233Eminus6

0350Eminus6

0466Eminus6

0583minus6

0700Eminus6

0816Eminus6

0933Eminus6

0105Eminus5

(a) The fundamental mode shape

Z

XY

minus0151Eminus3

minus0109Eminus3

minus0677Eminus4

minus0263Eminus4

0152Eminus4

0566Eminus4

0981Eminus4

0140Eminus3

0181Eminus3

0222Eminus3

MXMN

(b) The 2nd mode shape

Z

XY

minus0454Eminus3

minus0353Eminus3

minus0252Eminus3

minus0151Eminus3

minus0505Eminus4

0505Eminus4

0151Eminus3

0252Eminus3

0353Eminus3

0454Eminus3

MXMN

(c) The 3rd mode shape

Z

XY

minus0170Eminus6

minus0123Eminus6

minus0760Eminus7

minus0289Eminus7

0182Eminus7

0653Eminus7

0112Eminus6

0160Eminus6

0207Eminus6

0254Eminus6

MX

MN

(d) The 7th mode shape

Z

XY

minus0418Eminus6

minus0325Eminus6

minus0232Eminus6

minus0129Eminus6

minus0464Eminus7

0464Eminus7

0139Eminus6

0232Eminus6

0325Eminus6

0418Eminus6

MXMN

(e) The 9th mode shape

Z

XY

minus0329Eminus6

minus0258Eminus6

minus0186Eminus6

minus0114Eminus6

minus0421Eminus7

0294Eminus7

0101Eminus6

0173Eminus6

0245Eminus6

0317Eminus6

MX

MN

(f) The 13th mode shape

Figure 4 The mode shape of shield building

response of Case VI has more considerable amplitude at the15 secondsThis is probably caused by the deformation of theshield building roof corresponding to the highermodal shapesuch as 7th 9th and 13th The corresponding displacementresponses of Point 1 are illustrated in Figure 8 A similarresponse as the acceleration curve was obtained with the

maximum displacement of 256 246 239 226 216 and206 cm for six cases respectively

The maximum von Mises stress emerges at the jointof shield building wall and roof around the air intakeConsequently von Mises stress of the two selected points(Points 2 and 3 in Figure 1) around air intake is plotted in

6 Science and Technology of Nuclear Installations

NS

Gro

und

acce

lera

tion

(G)

Time (t)

02

01

00

minus01

minus02

0 10 20

Figure 5 The El Centro wave time history with 035 g

Z

XY

MX

MN

93421

0103E+07

0205E+07

0308E+07

0410E+07

0515E+07

0614E+07

0717E+07

0819E+07

0921E+07

(a) 258 seconds

265901

114610

226562

338513

450464

562415

674367

786318

898269

Z

XY

MX

MX0101E+07

(b) 264 seconds

Z

XY

MN

MX

353981

726279

0145E+07

0217E+07

0289E+07

0362E+07

0434E+07

0506E+07

0579E+07

0651E+07

(c) 26 seconds

Figure 6 The von Mises stress distribution of shield building of Case I

Table 4 The maximum transient data and the relative difference compared with Case I

Response Displacement (cm) Acceleration (ms2) von Mises stress (MPa)Position Point 1 Point 1 Point 2 Point 3Case I 2563 (0) 13410 (0) 6507 (0) 8563 (0)Case II 2469 (366) 12580 (618) 6270 (364) 8265 (348)Case III 2391 (671) 11599 (1351) 5554 (1460) 7330 (1440)Case IV 2269 (1147) 10777 (1963) 5096 (2168) 4946 (4224)Case V 2163 (1561) 9916 (2605) 4801 (2621) 4469 (4781)Case VI 2060 (1963) 9194 (3142) 4399 (3240) 4001 (5328)

Science and Technology of Nuclear Installations 7En

velo

pes o

f acc

eler

atio

n re

spon

se(m

s2)

Time (s)

14121086420

minus2minus4minus6minus8minus10minus12minus14minus16minus18

0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Figure 7 The envelopes of acceleration time history at Point 1

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Enve

lope

s of d

ispla

cem

ent r

espo

nse (

cm)

30

25

20

15

10

00

05

minus05

minus10

minus15

minus20

minus25

Figure 8 The envelopes of displacement time history at Point 1

Figures 9 and 10The twofigures show similar curveswith dif-ferent amplitudes Table 4 concludes the maximum value ofseismic response to different water levels in PCCWST and therelative difference compared with Case I It can be seen thatnearly all response values decreased with the reduced watervolume The decreased responses are basically following alinear pattern with the decreased water volume especially forthe displacement response acceleration response and stressresponse at Point 2 The results show that PCCWST withwater draining up is much safer than that with an operationalwater level The change is relatively large with a displacementreduction 196 an acceleration reduction 314 and a stressreduction 32 at Point 2 However the reduction of stressresponse at Point 3 is not linear which may be caused by thestress concentration

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Upp

er en

velo

pes o

f von

Mise

s stre

ss (M

Pa)

8

6

4

2

0

Figure 9 The upper envelopes of von Mises stress time history atPoint 3

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Upp

er en

velo

pes o

f von

Mise

s stre

ss (M

Pa) 7

6

5

4

3

2

1

0

Figure 10 The upper envelopes of von Mises stress time history atPoint 2

5 Conclusions

The structural modal and seismic response of shield buildinghave been investigated considering fluid-structure inter-action for different water levels The modal results showthe reduction of water level will increase the fundamentalfrequency of shield building as well as the modal frequencyof shape modal corresponding to the local deformation ofshield building roof and PCCWST For higher order ofmodal themodal frequency is hardly influenced by the waterlevel However the influence of water level is relatively smallbecause the water mass only takes up a very small proportionof shield building For seismic response of shield buildingthe maximum acceleration of shield building top for Case VI

8 Science and Technology of Nuclear Installations

is about 31 less than that of Case I The maximum dis-placement of the same position for Case VI is about 1963less than that of Case I The von Mises stress at differentpoint around the air intake for Case VI is about 32 and53 less than that of Case I All responses are inclining withthe reduction of water volume although the decreased stressresponses at air inlet corner are not following a linear patternwith the decreased water volume The results indicated thedecreasing water level will reduce the structure responsewhich means even when water in the PCCWST is drainingto empty the shield building can still stand the earthquakewith enough margin

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

The project was sponsored by National Science and Technol-ogy Major Project of the Ministry of Science and Technologyof China (2012ZX06004-012-004)

References

[1] C Zhao J Chen and Q Xu ldquoDynamic analysis of AP1000shield building for various elevations and shapes of air intakesconsidering FSI effects subjected to seismic loadingrdquo Progress inNuclear Energy vol 74 pp 44ndash52 2014

[2] M Jolie M M Hassan and A A El Damatty ldquoAssessmentof current design procedures for conical tanks under seismicloadingrdquo Canadian Journal of Civil Engineering vol 40 no 12pp 1151ndash1163 2013

[3] R Livaoglu and A Dogangun ldquoSimplified seismic analysisprocedures for elevated tanks considering fluid-structure-soilinteractionrdquo Journal of Fluids and Structures vol 22 no 3 pp421ndash439 2006

[4] M Moslemi M R Kianoush and W Pogorzelski ldquoSeismicresponse of liquid-filled elevated tanksrdquo Engineering Structuresvol 33 no 6 pp 2074ndash2084 2011

[5] M Masoudi S Eshghi and M Ghafory-Ashtiany ldquoEvaluationof response modification factor (R) of elevated concrete tanksrdquoEngineering Structures vol 39 pp 199ndash209 2012

[6] D-S Lee M-L Liu T-C Hung C-H Tsai and Y-TChen ldquoOptimal structural analysis with associated passiveheat removal for AP1000 shield buildingrdquo Applied ThermalEngineering vol 50 no 1 pp 207ndash216 2013

[7] Y Choi S Lim B-H Ko et al ldquoDynamic characteristicsidentification of reactor internals in SMART considering fluid-structure interactionrdquoNuclear Engineering and Design vol 255pp 202ndash211 2013

[8] WestinghouseThe AP1000 European DCD UKAP1000 SafetySecurity and Environmental Report p 51ndash53

[9] N Hosseinzadeh H Kazem M Ghahremannejad E Ahmadiand N Kazem ldquoComparison of API650-2008 provisions withFEM analyses for seismic assessment of existing steel oil storagetanksrdquo Journal of Loss Prevention in the Process Industries vol26 no 4 pp 666ndash675 2013

[10] H Sezen R Livaoglu and A Dogangun ldquoDynamic analysisand seismic performance evaluation of above-ground liquid-containing tanksrdquo Engineering Structures vol 30 no 3 pp 794ndash803 2008

TribologyAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

FuelsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofPetroleum Engineering

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Industrial EngineeringJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Power ElectronicsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

CombustionJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Renewable Energy

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

StructuresJournal of

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nuclear InstallationsScience and Technology of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Solar EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Wind EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nuclear EnergyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

High Energy PhysicsAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Page 5: Research Article AP1000 Shield Building Dynamic Response ...downloads.hindawi.com/journals/stni/2015/840507.pdf · AP1000 Shield Building Dynamic Response for Different Water ...

Science and Technology of Nuclear Installations 5

Z

XY

MX

MN

0

0117Eminus6

0233Eminus6

0350Eminus6

0466Eminus6

0583minus6

0700Eminus6

0816Eminus6

0933Eminus6

0105Eminus5

(a) The fundamental mode shape

Z

XY

minus0151Eminus3

minus0109Eminus3

minus0677Eminus4

minus0263Eminus4

0152Eminus4

0566Eminus4

0981Eminus4

0140Eminus3

0181Eminus3

0222Eminus3

MXMN

(b) The 2nd mode shape

Z

XY

minus0454Eminus3

minus0353Eminus3

minus0252Eminus3

minus0151Eminus3

minus0505Eminus4

0505Eminus4

0151Eminus3

0252Eminus3

0353Eminus3

0454Eminus3

MXMN

(c) The 3rd mode shape

Z

XY

minus0170Eminus6

minus0123Eminus6

minus0760Eminus7

minus0289Eminus7

0182Eminus7

0653Eminus7

0112Eminus6

0160Eminus6

0207Eminus6

0254Eminus6

MX

MN

(d) The 7th mode shape

Z

XY

minus0418Eminus6

minus0325Eminus6

minus0232Eminus6

minus0129Eminus6

minus0464Eminus7

0464Eminus7

0139Eminus6

0232Eminus6

0325Eminus6

0418Eminus6

MXMN

(e) The 9th mode shape

Z

XY

minus0329Eminus6

minus0258Eminus6

minus0186Eminus6

minus0114Eminus6

minus0421Eminus7

0294Eminus7

0101Eminus6

0173Eminus6

0245Eminus6

0317Eminus6

MX

MN

(f) The 13th mode shape

Figure 4 The mode shape of shield building

response of Case VI has more considerable amplitude at the15 secondsThis is probably caused by the deformation of theshield building roof corresponding to the highermodal shapesuch as 7th 9th and 13th The corresponding displacementresponses of Point 1 are illustrated in Figure 8 A similarresponse as the acceleration curve was obtained with the

maximum displacement of 256 246 239 226 216 and206 cm for six cases respectively

The maximum von Mises stress emerges at the jointof shield building wall and roof around the air intakeConsequently von Mises stress of the two selected points(Points 2 and 3 in Figure 1) around air intake is plotted in

6 Science and Technology of Nuclear Installations

NS

Gro

und

acce

lera

tion

(G)

Time (t)

02

01

00

minus01

minus02

0 10 20

Figure 5 The El Centro wave time history with 035 g

Z

XY

MX

MN

93421

0103E+07

0205E+07

0308E+07

0410E+07

0515E+07

0614E+07

0717E+07

0819E+07

0921E+07

(a) 258 seconds

265901

114610

226562

338513

450464

562415

674367

786318

898269

Z

XY

MX

MX0101E+07

(b) 264 seconds

Z

XY

MN

MX

353981

726279

0145E+07

0217E+07

0289E+07

0362E+07

0434E+07

0506E+07

0579E+07

0651E+07

(c) 26 seconds

Figure 6 The von Mises stress distribution of shield building of Case I

Table 4 The maximum transient data and the relative difference compared with Case I

Response Displacement (cm) Acceleration (ms2) von Mises stress (MPa)Position Point 1 Point 1 Point 2 Point 3Case I 2563 (0) 13410 (0) 6507 (0) 8563 (0)Case II 2469 (366) 12580 (618) 6270 (364) 8265 (348)Case III 2391 (671) 11599 (1351) 5554 (1460) 7330 (1440)Case IV 2269 (1147) 10777 (1963) 5096 (2168) 4946 (4224)Case V 2163 (1561) 9916 (2605) 4801 (2621) 4469 (4781)Case VI 2060 (1963) 9194 (3142) 4399 (3240) 4001 (5328)

Science and Technology of Nuclear Installations 7En

velo

pes o

f acc

eler

atio

n re

spon

se(m

s2)

Time (s)

14121086420

minus2minus4minus6minus8minus10minus12minus14minus16minus18

0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Figure 7 The envelopes of acceleration time history at Point 1

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Enve

lope

s of d

ispla

cem

ent r

espo

nse (

cm)

30

25

20

15

10

00

05

minus05

minus10

minus15

minus20

minus25

Figure 8 The envelopes of displacement time history at Point 1

Figures 9 and 10The twofigures show similar curveswith dif-ferent amplitudes Table 4 concludes the maximum value ofseismic response to different water levels in PCCWST and therelative difference compared with Case I It can be seen thatnearly all response values decreased with the reduced watervolume The decreased responses are basically following alinear pattern with the decreased water volume especially forthe displacement response acceleration response and stressresponse at Point 2 The results show that PCCWST withwater draining up is much safer than that with an operationalwater level The change is relatively large with a displacementreduction 196 an acceleration reduction 314 and a stressreduction 32 at Point 2 However the reduction of stressresponse at Point 3 is not linear which may be caused by thestress concentration

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Upp

er en

velo

pes o

f von

Mise

s stre

ss (M

Pa)

8

6

4

2

0

Figure 9 The upper envelopes of von Mises stress time history atPoint 3

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Upp

er en

velo

pes o

f von

Mise

s stre

ss (M

Pa) 7

6

5

4

3

2

1

0

Figure 10 The upper envelopes of von Mises stress time history atPoint 2

5 Conclusions

The structural modal and seismic response of shield buildinghave been investigated considering fluid-structure inter-action for different water levels The modal results showthe reduction of water level will increase the fundamentalfrequency of shield building as well as the modal frequencyof shape modal corresponding to the local deformation ofshield building roof and PCCWST For higher order ofmodal themodal frequency is hardly influenced by the waterlevel However the influence of water level is relatively smallbecause the water mass only takes up a very small proportionof shield building For seismic response of shield buildingthe maximum acceleration of shield building top for Case VI

8 Science and Technology of Nuclear Installations

is about 31 less than that of Case I The maximum dis-placement of the same position for Case VI is about 1963less than that of Case I The von Mises stress at differentpoint around the air intake for Case VI is about 32 and53 less than that of Case I All responses are inclining withthe reduction of water volume although the decreased stressresponses at air inlet corner are not following a linear patternwith the decreased water volume The results indicated thedecreasing water level will reduce the structure responsewhich means even when water in the PCCWST is drainingto empty the shield building can still stand the earthquakewith enough margin

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

The project was sponsored by National Science and Technol-ogy Major Project of the Ministry of Science and Technologyof China (2012ZX06004-012-004)

References

[1] C Zhao J Chen and Q Xu ldquoDynamic analysis of AP1000shield building for various elevations and shapes of air intakesconsidering FSI effects subjected to seismic loadingrdquo Progress inNuclear Energy vol 74 pp 44ndash52 2014

[2] M Jolie M M Hassan and A A El Damatty ldquoAssessmentof current design procedures for conical tanks under seismicloadingrdquo Canadian Journal of Civil Engineering vol 40 no 12pp 1151ndash1163 2013

[3] R Livaoglu and A Dogangun ldquoSimplified seismic analysisprocedures for elevated tanks considering fluid-structure-soilinteractionrdquo Journal of Fluids and Structures vol 22 no 3 pp421ndash439 2006

[4] M Moslemi M R Kianoush and W Pogorzelski ldquoSeismicresponse of liquid-filled elevated tanksrdquo Engineering Structuresvol 33 no 6 pp 2074ndash2084 2011

[5] M Masoudi S Eshghi and M Ghafory-Ashtiany ldquoEvaluationof response modification factor (R) of elevated concrete tanksrdquoEngineering Structures vol 39 pp 199ndash209 2012

[6] D-S Lee M-L Liu T-C Hung C-H Tsai and Y-TChen ldquoOptimal structural analysis with associated passiveheat removal for AP1000 shield buildingrdquo Applied ThermalEngineering vol 50 no 1 pp 207ndash216 2013

[7] Y Choi S Lim B-H Ko et al ldquoDynamic characteristicsidentification of reactor internals in SMART considering fluid-structure interactionrdquoNuclear Engineering and Design vol 255pp 202ndash211 2013

[8] WestinghouseThe AP1000 European DCD UKAP1000 SafetySecurity and Environmental Report p 51ndash53

[9] N Hosseinzadeh H Kazem M Ghahremannejad E Ahmadiand N Kazem ldquoComparison of API650-2008 provisions withFEM analyses for seismic assessment of existing steel oil storagetanksrdquo Journal of Loss Prevention in the Process Industries vol26 no 4 pp 666ndash675 2013

[10] H Sezen R Livaoglu and A Dogangun ldquoDynamic analysisand seismic performance evaluation of above-ground liquid-containing tanksrdquo Engineering Structures vol 30 no 3 pp 794ndash803 2008

TribologyAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

FuelsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofPetroleum Engineering

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Industrial EngineeringJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Power ElectronicsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

CombustionJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Renewable Energy

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

StructuresJournal of

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nuclear InstallationsScience and Technology of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Solar EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Wind EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nuclear EnergyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

High Energy PhysicsAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Page 6: Research Article AP1000 Shield Building Dynamic Response ...downloads.hindawi.com/journals/stni/2015/840507.pdf · AP1000 Shield Building Dynamic Response for Different Water ...

6 Science and Technology of Nuclear Installations

NS

Gro

und

acce

lera

tion

(G)

Time (t)

02

01

00

minus01

minus02

0 10 20

Figure 5 The El Centro wave time history with 035 g

Z

XY

MX

MN

93421

0103E+07

0205E+07

0308E+07

0410E+07

0515E+07

0614E+07

0717E+07

0819E+07

0921E+07

(a) 258 seconds

265901

114610

226562

338513

450464

562415

674367

786318

898269

Z

XY

MX

MX0101E+07

(b) 264 seconds

Z

XY

MN

MX

353981

726279

0145E+07

0217E+07

0289E+07

0362E+07

0434E+07

0506E+07

0579E+07

0651E+07

(c) 26 seconds

Figure 6 The von Mises stress distribution of shield building of Case I

Table 4 The maximum transient data and the relative difference compared with Case I

Response Displacement (cm) Acceleration (ms2) von Mises stress (MPa)Position Point 1 Point 1 Point 2 Point 3Case I 2563 (0) 13410 (0) 6507 (0) 8563 (0)Case II 2469 (366) 12580 (618) 6270 (364) 8265 (348)Case III 2391 (671) 11599 (1351) 5554 (1460) 7330 (1440)Case IV 2269 (1147) 10777 (1963) 5096 (2168) 4946 (4224)Case V 2163 (1561) 9916 (2605) 4801 (2621) 4469 (4781)Case VI 2060 (1963) 9194 (3142) 4399 (3240) 4001 (5328)

Science and Technology of Nuclear Installations 7En

velo

pes o

f acc

eler

atio

n re

spon

se(m

s2)

Time (s)

14121086420

minus2minus4minus6minus8minus10minus12minus14minus16minus18

0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Figure 7 The envelopes of acceleration time history at Point 1

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Enve

lope

s of d

ispla

cem

ent r

espo

nse (

cm)

30

25

20

15

10

00

05

minus05

minus10

minus15

minus20

minus25

Figure 8 The envelopes of displacement time history at Point 1

Figures 9 and 10The twofigures show similar curveswith dif-ferent amplitudes Table 4 concludes the maximum value ofseismic response to different water levels in PCCWST and therelative difference compared with Case I It can be seen thatnearly all response values decreased with the reduced watervolume The decreased responses are basically following alinear pattern with the decreased water volume especially forthe displacement response acceleration response and stressresponse at Point 2 The results show that PCCWST withwater draining up is much safer than that with an operationalwater level The change is relatively large with a displacementreduction 196 an acceleration reduction 314 and a stressreduction 32 at Point 2 However the reduction of stressresponse at Point 3 is not linear which may be caused by thestress concentration

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Upp

er en

velo

pes o

f von

Mise

s stre

ss (M

Pa)

8

6

4

2

0

Figure 9 The upper envelopes of von Mises stress time history atPoint 3

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Upp

er en

velo

pes o

f von

Mise

s stre

ss (M

Pa) 7

6

5

4

3

2

1

0

Figure 10 The upper envelopes of von Mises stress time history atPoint 2

5 Conclusions

The structural modal and seismic response of shield buildinghave been investigated considering fluid-structure inter-action for different water levels The modal results showthe reduction of water level will increase the fundamentalfrequency of shield building as well as the modal frequencyof shape modal corresponding to the local deformation ofshield building roof and PCCWST For higher order ofmodal themodal frequency is hardly influenced by the waterlevel However the influence of water level is relatively smallbecause the water mass only takes up a very small proportionof shield building For seismic response of shield buildingthe maximum acceleration of shield building top for Case VI

8 Science and Technology of Nuclear Installations

is about 31 less than that of Case I The maximum dis-placement of the same position for Case VI is about 1963less than that of Case I The von Mises stress at differentpoint around the air intake for Case VI is about 32 and53 less than that of Case I All responses are inclining withthe reduction of water volume although the decreased stressresponses at air inlet corner are not following a linear patternwith the decreased water volume The results indicated thedecreasing water level will reduce the structure responsewhich means even when water in the PCCWST is drainingto empty the shield building can still stand the earthquakewith enough margin

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

The project was sponsored by National Science and Technol-ogy Major Project of the Ministry of Science and Technologyof China (2012ZX06004-012-004)

References

[1] C Zhao J Chen and Q Xu ldquoDynamic analysis of AP1000shield building for various elevations and shapes of air intakesconsidering FSI effects subjected to seismic loadingrdquo Progress inNuclear Energy vol 74 pp 44ndash52 2014

[2] M Jolie M M Hassan and A A El Damatty ldquoAssessmentof current design procedures for conical tanks under seismicloadingrdquo Canadian Journal of Civil Engineering vol 40 no 12pp 1151ndash1163 2013

[3] R Livaoglu and A Dogangun ldquoSimplified seismic analysisprocedures for elevated tanks considering fluid-structure-soilinteractionrdquo Journal of Fluids and Structures vol 22 no 3 pp421ndash439 2006

[4] M Moslemi M R Kianoush and W Pogorzelski ldquoSeismicresponse of liquid-filled elevated tanksrdquo Engineering Structuresvol 33 no 6 pp 2074ndash2084 2011

[5] M Masoudi S Eshghi and M Ghafory-Ashtiany ldquoEvaluationof response modification factor (R) of elevated concrete tanksrdquoEngineering Structures vol 39 pp 199ndash209 2012

[6] D-S Lee M-L Liu T-C Hung C-H Tsai and Y-TChen ldquoOptimal structural analysis with associated passiveheat removal for AP1000 shield buildingrdquo Applied ThermalEngineering vol 50 no 1 pp 207ndash216 2013

[7] Y Choi S Lim B-H Ko et al ldquoDynamic characteristicsidentification of reactor internals in SMART considering fluid-structure interactionrdquoNuclear Engineering and Design vol 255pp 202ndash211 2013

[8] WestinghouseThe AP1000 European DCD UKAP1000 SafetySecurity and Environmental Report p 51ndash53

[9] N Hosseinzadeh H Kazem M Ghahremannejad E Ahmadiand N Kazem ldquoComparison of API650-2008 provisions withFEM analyses for seismic assessment of existing steel oil storagetanksrdquo Journal of Loss Prevention in the Process Industries vol26 no 4 pp 666ndash675 2013

[10] H Sezen R Livaoglu and A Dogangun ldquoDynamic analysisand seismic performance evaluation of above-ground liquid-containing tanksrdquo Engineering Structures vol 30 no 3 pp 794ndash803 2008

TribologyAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

FuelsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofPetroleum Engineering

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Industrial EngineeringJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Power ElectronicsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

CombustionJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Renewable Energy

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

StructuresJournal of

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nuclear InstallationsScience and Technology of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Solar EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Wind EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nuclear EnergyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

High Energy PhysicsAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Page 7: Research Article AP1000 Shield Building Dynamic Response ...downloads.hindawi.com/journals/stni/2015/840507.pdf · AP1000 Shield Building Dynamic Response for Different Water ...

Science and Technology of Nuclear Installations 7En

velo

pes o

f acc

eler

atio

n re

spon

se(m

s2)

Time (s)

14121086420

minus2minus4minus6minus8minus10minus12minus14minus16minus18

0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Figure 7 The envelopes of acceleration time history at Point 1

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Enve

lope

s of d

ispla

cem

ent r

espo

nse (

cm)

30

25

20

15

10

00

05

minus05

minus10

minus15

minus20

minus25

Figure 8 The envelopes of displacement time history at Point 1

Figures 9 and 10The twofigures show similar curveswith dif-ferent amplitudes Table 4 concludes the maximum value ofseismic response to different water levels in PCCWST and therelative difference compared with Case I It can be seen thatnearly all response values decreased with the reduced watervolume The decreased responses are basically following alinear pattern with the decreased water volume especially forthe displacement response acceleration response and stressresponse at Point 2 The results show that PCCWST withwater draining up is much safer than that with an operationalwater level The change is relatively large with a displacementreduction 196 an acceleration reduction 314 and a stressreduction 32 at Point 2 However the reduction of stressresponse at Point 3 is not linear which may be caused by thestress concentration

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Upp

er en

velo

pes o

f von

Mise

s stre

ss (M

Pa)

8

6

4

2

0

Figure 9 The upper envelopes of von Mises stress time history atPoint 3

Time (s)0 5 10 15 20

Case ICase IICase III

Case IVCase VCase VI

Upp

er en

velo

pes o

f von

Mise

s stre

ss (M

Pa) 7

6

5

4

3

2

1

0

Figure 10 The upper envelopes of von Mises stress time history atPoint 2

5 Conclusions

The structural modal and seismic response of shield buildinghave been investigated considering fluid-structure inter-action for different water levels The modal results showthe reduction of water level will increase the fundamentalfrequency of shield building as well as the modal frequencyof shape modal corresponding to the local deformation ofshield building roof and PCCWST For higher order ofmodal themodal frequency is hardly influenced by the waterlevel However the influence of water level is relatively smallbecause the water mass only takes up a very small proportionof shield building For seismic response of shield buildingthe maximum acceleration of shield building top for Case VI

8 Science and Technology of Nuclear Installations

is about 31 less than that of Case I The maximum dis-placement of the same position for Case VI is about 1963less than that of Case I The von Mises stress at differentpoint around the air intake for Case VI is about 32 and53 less than that of Case I All responses are inclining withthe reduction of water volume although the decreased stressresponses at air inlet corner are not following a linear patternwith the decreased water volume The results indicated thedecreasing water level will reduce the structure responsewhich means even when water in the PCCWST is drainingto empty the shield building can still stand the earthquakewith enough margin

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

The project was sponsored by National Science and Technol-ogy Major Project of the Ministry of Science and Technologyof China (2012ZX06004-012-004)

References

[1] C Zhao J Chen and Q Xu ldquoDynamic analysis of AP1000shield building for various elevations and shapes of air intakesconsidering FSI effects subjected to seismic loadingrdquo Progress inNuclear Energy vol 74 pp 44ndash52 2014

[2] M Jolie M M Hassan and A A El Damatty ldquoAssessmentof current design procedures for conical tanks under seismicloadingrdquo Canadian Journal of Civil Engineering vol 40 no 12pp 1151ndash1163 2013

[3] R Livaoglu and A Dogangun ldquoSimplified seismic analysisprocedures for elevated tanks considering fluid-structure-soilinteractionrdquo Journal of Fluids and Structures vol 22 no 3 pp421ndash439 2006

[4] M Moslemi M R Kianoush and W Pogorzelski ldquoSeismicresponse of liquid-filled elevated tanksrdquo Engineering Structuresvol 33 no 6 pp 2074ndash2084 2011

[5] M Masoudi S Eshghi and M Ghafory-Ashtiany ldquoEvaluationof response modification factor (R) of elevated concrete tanksrdquoEngineering Structures vol 39 pp 199ndash209 2012

[6] D-S Lee M-L Liu T-C Hung C-H Tsai and Y-TChen ldquoOptimal structural analysis with associated passiveheat removal for AP1000 shield buildingrdquo Applied ThermalEngineering vol 50 no 1 pp 207ndash216 2013

[7] Y Choi S Lim B-H Ko et al ldquoDynamic characteristicsidentification of reactor internals in SMART considering fluid-structure interactionrdquoNuclear Engineering and Design vol 255pp 202ndash211 2013

[8] WestinghouseThe AP1000 European DCD UKAP1000 SafetySecurity and Environmental Report p 51ndash53

[9] N Hosseinzadeh H Kazem M Ghahremannejad E Ahmadiand N Kazem ldquoComparison of API650-2008 provisions withFEM analyses for seismic assessment of existing steel oil storagetanksrdquo Journal of Loss Prevention in the Process Industries vol26 no 4 pp 666ndash675 2013

[10] H Sezen R Livaoglu and A Dogangun ldquoDynamic analysisand seismic performance evaluation of above-ground liquid-containing tanksrdquo Engineering Structures vol 30 no 3 pp 794ndash803 2008

TribologyAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

FuelsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofPetroleum Engineering

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Industrial EngineeringJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Power ElectronicsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

CombustionJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Renewable Energy

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

StructuresJournal of

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nuclear InstallationsScience and Technology of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Solar EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Wind EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nuclear EnergyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

High Energy PhysicsAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Page 8: Research Article AP1000 Shield Building Dynamic Response ...downloads.hindawi.com/journals/stni/2015/840507.pdf · AP1000 Shield Building Dynamic Response for Different Water ...

8 Science and Technology of Nuclear Installations

is about 31 less than that of Case I The maximum dis-placement of the same position for Case VI is about 1963less than that of Case I The von Mises stress at differentpoint around the air intake for Case VI is about 32 and53 less than that of Case I All responses are inclining withthe reduction of water volume although the decreased stressresponses at air inlet corner are not following a linear patternwith the decreased water volume The results indicated thedecreasing water level will reduce the structure responsewhich means even when water in the PCCWST is drainingto empty the shield building can still stand the earthquakewith enough margin

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

The project was sponsored by National Science and Technol-ogy Major Project of the Ministry of Science and Technologyof China (2012ZX06004-012-004)

References

[1] C Zhao J Chen and Q Xu ldquoDynamic analysis of AP1000shield building for various elevations and shapes of air intakesconsidering FSI effects subjected to seismic loadingrdquo Progress inNuclear Energy vol 74 pp 44ndash52 2014

[2] M Jolie M M Hassan and A A El Damatty ldquoAssessmentof current design procedures for conical tanks under seismicloadingrdquo Canadian Journal of Civil Engineering vol 40 no 12pp 1151ndash1163 2013

[3] R Livaoglu and A Dogangun ldquoSimplified seismic analysisprocedures for elevated tanks considering fluid-structure-soilinteractionrdquo Journal of Fluids and Structures vol 22 no 3 pp421ndash439 2006

[4] M Moslemi M R Kianoush and W Pogorzelski ldquoSeismicresponse of liquid-filled elevated tanksrdquo Engineering Structuresvol 33 no 6 pp 2074ndash2084 2011

[5] M Masoudi S Eshghi and M Ghafory-Ashtiany ldquoEvaluationof response modification factor (R) of elevated concrete tanksrdquoEngineering Structures vol 39 pp 199ndash209 2012

[6] D-S Lee M-L Liu T-C Hung C-H Tsai and Y-TChen ldquoOptimal structural analysis with associated passiveheat removal for AP1000 shield buildingrdquo Applied ThermalEngineering vol 50 no 1 pp 207ndash216 2013

[7] Y Choi S Lim B-H Ko et al ldquoDynamic characteristicsidentification of reactor internals in SMART considering fluid-structure interactionrdquoNuclear Engineering and Design vol 255pp 202ndash211 2013

[8] WestinghouseThe AP1000 European DCD UKAP1000 SafetySecurity and Environmental Report p 51ndash53

[9] N Hosseinzadeh H Kazem M Ghahremannejad E Ahmadiand N Kazem ldquoComparison of API650-2008 provisions withFEM analyses for seismic assessment of existing steel oil storagetanksrdquo Journal of Loss Prevention in the Process Industries vol26 no 4 pp 666ndash675 2013

[10] H Sezen R Livaoglu and A Dogangun ldquoDynamic analysisand seismic performance evaluation of above-ground liquid-containing tanksrdquo Engineering Structures vol 30 no 3 pp 794ndash803 2008

TribologyAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

FuelsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofPetroleum Engineering

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Industrial EngineeringJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Power ElectronicsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

CombustionJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Renewable Energy

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

StructuresJournal of

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nuclear InstallationsScience and Technology of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Solar EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Wind EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nuclear EnergyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

High Energy PhysicsAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Page 9: Research Article AP1000 Shield Building Dynamic Response ...downloads.hindawi.com/journals/stni/2015/840507.pdf · AP1000 Shield Building Dynamic Response for Different Water ...

TribologyAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

FuelsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal ofPetroleum Engineering

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Industrial EngineeringJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Power ElectronicsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

CombustionJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Renewable Energy

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

StructuresJournal of

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nuclear InstallationsScience and Technology of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Solar EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Wind EnergyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Nuclear EnergyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

High Energy PhysicsAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014