benchmark information theme a - ancold · th icold international benchmark workshop summary - theme...

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Institute of Hydraulic Engineering

12th ICOLD International Benchmark Workshop Summary - Theme A

ATCOLD

Austrian National Committee on Large Dams

Benchmark Information

Theme A

Fluid Structure Interaction

Arch Dam – Reservoir

modeling

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Introduction

Focus of this Benchmark

• Dynamic Fluid Structure Interaction modeling

• Application of different Approaches - Added mass technique (Westergaard, Zangar,…)

- Acoustic Elements

- Fluid Elements

- …

• Different Boundary Conditions - Dam - Foundation

Constraint

- Reservoir - Foundation

Reflecting on the sides

Non-reflecting at the end of the reservoir

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Introduction

Boundary Conditions

• Same spatial discretization (Model/Mesh) of

the Structure, Foundation and Reservoir

• Same Material Parameters

• Acceleration-Time-History in X-,Y-,Z-Direction

• Reservoir is infinite in length (non-reflecting)

• Rayleigh Damping

• Results to be compared – Visualization

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Model and Geometry

Artificial - Arch Dam Model

– Symmetry

– Total Height: 220 Meters

– Valley width (crest): ~ 430 Meters

– Valley width (bottom): ~ 80 Meters

Artificial Foundation Model

– Symmetry

– Height: 500 Meters

– Length: 1000 Meters

– Width: 1000 Meters

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Model and Geometrie

Reservoir Model

– Length: min. 460 Meters (approx. 2x Height)

– For modelling of the interaction with Acoustic- or Fluid Elements

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Acceleration modelling

Transient Acceleration

– X-,Y-,Z- Direction

– Artificially generated

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Material Parameters

Material properties

Rock mass

• Density: 0 kg/m3

• Poisson - ratio: 0,2

• Youngs - modulus: 25 GPa

Reservoir


• Bulk - modulus: 2,2 GPa

Rayleigh damping coefficients

α = …

β = …

Dam


• Poisson - ratio: 0,167

• Youngs - modulus: 27 GPa

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Mesh Properties

Coarse Mesh

Fine Mesh

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Loads

Gravity

– Isotropic

– Orthotropic

Hydrostatic Water Load

Seismic Loading

– Modal Superposition or

– Direct Integration (Implicit/Explicit)

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Results

Participants

Finite Element Program Method Mesh Some Additional Informations

A ABAQUS Acoustic Elements Coarse 7.5% critical damping

B DIANA Acoustic Elements Coarse Compressible Fluid, Hybrid Frequency-Time

Domain (HFTD) method

C CANT-SD Acoustic Elements Coarse

D DIANA Acoustic Elements Coarse Same as participant B, Construction steps

for loadcase deadweight

E DIANA Added mass (Westergaard) Fine Edyn = Esta * 1.25

F ABAQUS Acoustic Elements Coarse

G ABAQUS Acoustic Elements Fine

Infinite Elements at the boundaries,

Acceleration-Time-History applied on the

bottom of the model

H FENAS ECCON IPP Added mass (Westergaard) Fine Construction steps for loadcase deadweight

I ANSYS Added mass (Westergaard) Coarse Use of the full Westergaard formula

(Period/Frequency dependent)

J COMSOL Acoustic Elements Coarse

K CODE_ASTER

(Open Source)

Incompressible Finite Element

added mass Coarse

Method to calculate the added mass

matrices representing the fluid-structure

interaction with a potential approach

REF ABAQUS Acoustic Elements Coarse

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Results

Eigenfrequencies and Mode Shapes (Participants A-E)

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Results

Eigenfrequencies and Mode Shapes (Participants F-K)

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Results

Eigenfrequencies

0

1

2

3

4

5

6

1 2 3 4 5 6 7 8 9 10

FREQ

UEN

CY

(H

z)

MODE NUMBER

A B C D E F G H I J K REF

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Results

Deformations (only static)

0 20 40 60 80

100 120 140 160 180 200 220

0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09

HEI

GH

T (m

)

DEFORMATION (m) F G H I J K REF

0 20 40 60 80

100 120 140 160 180 200 220

0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09

HEI

GH

T (m

)

DEFORMATION (m) A B C D E REF

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Results

Deformations (only dynamic)

0 20 40 60 80

100 120 140 160 180 200 220

-0.15 -0.10 -0.05 0.00 0.05 0.10

HEI

GH

T (m

)

DEFORMATION (m) A B C D E REF

0 20 40 60 80

100 120 140 160 180 200 220

-0.15 -0.10 -0.05 0.00 0.05 0.10

HEI

GH

T (m

)

DEFORMATION (m) F G H I J K REF

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Results

Hoop Stresses (only static) – Main Section – Upstream

0 20 40 60 80

100 120 140 160 180 200 220

-8.00 -7.00 -6.00 -5.00 -4.00 -3.00 -2.00 -1.00 0.00 1.00 2.00

HEI

GH

T (m

)

HOOP STRESS (MPa) A B C D E REF

0 20 40 60 80

100 120 140 160 180 200 220

-8.00 -7.00 -6.00 -5.00 -4.00 -3.00 -2.00 -1.00 0.00 1.00 2.00

HEI

GH

T (m

)

HOOP STRESS (MPa) F G H I J K REF

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Results

Hoop Stresses (only dynamic) – Main Section – Upstream

0 20 40 60 80

100 120 140 160 180 200 220

-10.00 -8.00 -6.00 -4.00 -2.00 0.00 2.00 4.00 6.00 8.00 10.00

HEI

GH

T (m

)

HOOP STRESS (MPa) A B C D E REF

0 20 40 60 80

100 120 140 160 180 200 220

-10.00 -8.00 -6.00 -4.00 -2.00 0.00 2.00 4.00 6.00 8.00 10.00

HEI

GH

T (m

)

HOOP STRESS (MPa) F G H I J K REF

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Results

Vertical Stresses – Main Section – Upstream

0 20 40 60 80

100 120 140 160 180 200 220

-6.00 -1.00 4.00 9.00

HEI

GH

T (m

)

VERTICAL STRESS (MPa) A B C D E REF

0 20 40 60 80

100 120 140 160 180 200 220

-6.00 -1.00 4.00 9.00

HEI

GH

T (m

)

VERTICAL STRESS (MPa) F G H I J K REF

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Results

Vertical Stresses – Main Section – Downstream

0 20 40 60 80

100 120 140 160 180 200 220

-12.00 -10.00 -8.00 -6.00 -4.00 -2.00 0.00 2.00 4.00

HEI

GH

T (m

)

VERTICAL STRESS (MPa) A B C D E REF

0 20 40 60 80

100 120 140 160 180 200 220

-12.00 -10.00 -8.00 -6.00 -4.00 -2.00 0.00 2.00 4.00

HEI

GH

T (m

)

VERTICAL STRESS (MPa) F G H I J K REF

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Results

Following additional results are to be found in the final proceedings

Hoop Stresses in the Left and Right Section (Upstream and Downstream)

Vertical Stresses in Left and Right Section (Upstream and Downstream)

Minimum Principal Stresses in Left and Right Section (Upstream and Downstream)

Maximum Principal Stresses in Left and Right Section (Upstream and Downstream)

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