Application of Fluid- Structure Interaction Algorithms to Seismic Analysis of Liquid Storage Tanks Zuhal OZDEMIR, Mhamed SOULI Université des Sciences et Technologies de Lille Laboratoire de Mécanique de Lille University of Bosphor, Istanbul
Transcript
Slide 1
Application of Fluid-Structure Interaction Algorithms to
Seismic Analysis of Liquid Storage Tanks Zuhal OZDEMIR, Mhamed
SOULI Universit des Sciences et Technologies de Lille Laboratoire
de Mcanique de Lille University of Bosphor, Istanbul
Slide 2
Outline of the Presentation General Objective of the Studies
Carried out on Tanks Difficulties in the Analysis of Tanks Analysis
Methods for Tanks Fluid-Structure Interaction for Tank Problems 2D
Rigid Tank 3D Flexible Tank
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- Limit the tank damages observed during earthquakes -
Determine the response parameters in order to take precautions -
sloshing wave height (freeboard) - uplift displacement (flexible
attachments for pipes) General Objective of the Studies Carried out
on Tanks
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Difficulties in the Analysis of Tanks - Three different domains
* Structure * Fluid * Soil - Material and geometric nonlinearities
- Complex support condition * Anchored * Unanchored
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- Large amplitude wall deformations (Buckling) - Violent
sloshing which causes damage at the tank wall and shell General
Performance of Tanks during Earthquakes - High plastic deformation
at the tank base Sloshing damage
Analysis Methods for Tanks Irrotational flow, incompressible
and inviscid fluid (potantiaql flow theory) - Simplified Analytical
Methods Fluid : Laplace equation Spring-Mass Equivalent Analogue
Most of the provisions recommended in the current tank design codes
employ a modified version of Housners method Structure : rigid tank
Base Shear and Overturning Moment Ordinary Beam Theory Shell
Stresses (Axial Compressive and Hoop)
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Analysis Methods for Tanks (cond) - Numerical Methods FEM is
the best choice, because -structure, fluid and soil can be modelled
in the same system -proper modelling of contact boundary conditions
-nonlinear formulation for fluid and structure -nonlinear
formulation for fluid and structure interaction effects * 2D finite
difference method * FEM * BEM * Volume of fluid technique
(VOF)
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Structure Fluid Lagrangian Formulation Dynamic Structure
equation Navier Stokes equations in ALE Formulation Fluid-Structure
Interaction for Tank Problems
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2D Tank Problem width = 57 cm height = 30 cm H water = 15 cm
Sinusoidal harmonic motion non-resonance case resonance case The
sketch of the 2D sloshing experiment (Liu and Lin, 2008) o = 6.0578
rad/s
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2D Tank Problem Lagrangian
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ALE 2D Tank Problem
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= 0.583 o = 1 o non-resonance case resonance case amplitude =
0.005 m
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3D Tank Problem Cylindrical tank size: - radius of 1.83 m - a
total height of 1.83 m - filled up to height of 1.524 m Maximum
ground acceleration = 0.5 g in horizontal direction (El Centro
Earthquake record scaled with )
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3D Tank Problem Change of free surface in time
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3D Tank Problem Von Mises stresses on the anchored tank
shell
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3D Tank Problem Von Mises stresses on the unanchored tank shell
(displacements magnified 10 times)
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3D Tank Problem Comparisons of the time histories of pressure
for the numerical method and experimental data
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3D Tank Problem Comparisons of the time histories of pressure
for the numerical method and experimental data
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3D Tank Problem Comparisons of the time histories of surface
elevation for the numerical method and experimental data
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3D Tank Problem Comparisons of the time histories of tank base
uplift for the numerical method and experimental data
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Conclusions (1) ALE algorithm lead highly consisted results
with the experimental data in terms of peak level timing, shape and
amplitude of pressure and sloshing. (2) Method gives reliable
results for every frequency range of external excitation. (3) ALE
method combined with/without the contact algorithms can be utilized
as a design tool for the seismic analysis of rigid and flexible
liquid containment tanks. (4) As a further study, a real size tank
will be analysed
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THANK YOU
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3D Tank Problem Pressure distribution inside the tank
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Analysis Methods for Tanks (cond) - Experimental Methods *
Static tilt tests * Shaking table tests Schematic view of static
tilt test A cylindrical tank mounted on the shaking table