Testing of interface componentsTesting of interface components Armelle ANTHOINE and Pierre PEGON...
Transcript of Testing of interface componentsTesting of interface components Armelle ANTHOINE and Pierre PEGON...
Testing of interface components
Armelle ANTHOINE and Pierre PEGON
European Laboratory for Structural Assessment (ELSA)
Joint Research Centre (JRC)
Ispra, ITALY
SAFECONSTRUCT (European Standards) for Buildings and other Civil Engineering constructions under Earthquake, and other environmental and live loading
PVACS (European Guidelines) for Physical Vulnerability Assessment of Critical Structures under Impact and Blast loading
STEC (Performance standards for innovative technologies ) in the area of tamper-proof intermodal containers Supply Chain Security, Competitivness
ELSA Unit:
Actions and Activity fields
“Quasi-static” tests
Real size scale
Close loop
Dynamic tests
Reduced scale
Open loop
Earthquake simulation in the Lab
Shaking table
Reaction wall
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The Pseudo-dynamic methods
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Servo-Hydraulic
Actuators
Displacement
Transducers
Reference
Frame
Measured
Restoring Force )(tR
ga
dt...
Accelerogram
Force
Transducers
( ) ( ) ( ) gMa t Cv t R t MIa
Numerical Model
Imposed
Displacement ( )d t
Reaction wall at ELSA
22 actuators from 50t a 100t
2 testing platforms
Unique installation in Europe
Partner of infrastructure network
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Bending moment
200 MNm
Bending moment
240 MNm
16m
4.2m
25m 4m 5m
20m
13m
20m
Anchor holes
1m spacing
Base Shear
20 MN
SERIES/SERFIN project (end 2011)
“Special tests”: TESSH project in IRIS
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• Cyclic tests
• Cracking damage regime
• Ultimate state
• Control of the rotation
3m 1.2m
Thickness=40cm
Pipe crossing a seismic gap
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Pipe characteristics
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• DN300: Re = 157.5 mm, Ri = 142.5 mm, t = 25. mm
• p = 200. bar
• Gas (steam) or fluid (water)
• Temperature between 335oC and 500oC
• Geometry of the pipe: Z shape 6.25 m x 2 m
• Position and type of joints: 2 gimbals + 1 single hinge
• Boundary conditions: pipe clamped at both ends
Involved phenomena
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• Seismic loading Horizontal displacements imposed at one end
+ vertical displacement imposed at both ends
• Large displacement and rotations Geometric nonlinearity
• Internal pressure p Thrust in curved parts: T=2pR2cos(/2)
– Elbows
– Activated joints
• Fluid velocity vf Additional thrust: T=2fvf2R2cos(/2)
• Mass of the fluid f Higher weight and inertia (lower frequency)
Objective: Identify a representative test
Chosen numerical model
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• Pipe:
Elastic Navier Bernoulli beam with hollow circular section. Steel
material (Es, s, s).
• Joint:
Elastic Navier Bernoulli beam with hollow circular section. Soft
material (Es/10000, s, s).
+
Timoshenko beam with hollow circular section but zero inertia in
the rotation axes (y and z or z only). Stiff material (100Es, s, s).
• Fluid/gas:
Internal pressure (+ possible mass flow) in the Navier Bernoulli
beams (p or p+fvf2).
+
Increased volumetric mass of the Navier Bernoulli beams.
Loading
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• Gravity :
Configuration independent load applied statically at the beginning
and maintained constant during the seismic loading.
• Pressure (and/or flow):
Configuration dependent load applied statically at the beginning
and actualised during the seismic loading.
• Seismic loading:
Imposed displacement history at the extremities of the pipe.
uz(t) at both extremities, ux(t) and uy(t) at one extremity only.
Seismic input
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Acceleration and displacement time histories
Response spectra for 2% damping
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Preliminary modal analysis
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• Configuration 1:
Displacements and rotations blocked at both ends
• Configuration 2:
ux and uy free at one end.
• With/without fluid mass
Results:
• Frequency
• modal mass
• participation factors in x, y and z
• mode shape
Modal analysis results without fluid
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Fre1 Fre2 Mas1 Mas2 PFx1 PFx2 PFy1 PFy2 PFz1 PFz2
- .406 - 666. - -.679 - .675 - 0
- 1.15 - 546. - .747 - .442 - 0
19.1 220. 0 0 1.48
46.3 - 471. - -.0323 - 1.26 - 0 -
- 51.1 - 392 - -.301 - -1.06 - 0
52.5 159 0 0 0.918
Modal analysis results with fluid
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Fre1 Fre2 Mas1 Mas2 PFx1 PFx2 PFy1 PFy2 PFz1 PFz2
- .327 - 1025. - -.679 - .675 - 0
- 0.927 - 842. - .747 - .442 - 0
15.4 337. 0 0 1.48
37.4 - 753 - -.0323 - 1.26 - 0 -
- 41,3 - 605 - -.301 - -1.06 - 0
42.8 240 0 0 0.912
Preliminary conclusions
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• Vertical seismic loading: the first mode with a participation in z
has a frequency > 15 Hz very low displacement amplitude
• Horizontal seismic loading: apart from the two mechanisms, the
first mode with a participation in x or y has a frequency > 37 Hz
very low displacement amplitude (?)
• Only the two mechanisms should be substantially activated.
BUT
• Effects of the geometric non-linearity and of the pressure thrust
have not been taken into account.
Loading
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• Gravity :
Configuration independent load applied statically at the beginning
and maintained constant during the seismic loading.
• Pressure (and/or flow):
Configuration dependent load applied statically at the beginning
and actualised during the seismic loading.
• Seismic loading:
Imposed displacement history at the extremities of the pipe.
uz(t) at both extremities, ux(t) and uy(t) at one extremity only.
Non-linear calculations
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• Static/dynamic analysis (2% damping on the first mode > 15Hz)
Small differences on u and
• With/without vertical component Small differences on u and
• With/without internal pressure Small differences on u but large
differences on owing to the pressure.
• With/without fluid mass Small differences on u and , except
when the system reaches its limit.
Representative testing
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• The horizontal differential displacements can be imposed either
statically or dynamically.
• The vertical seismic displacements can be neglected
• The pipe should be pressurized (safety measures cost?)
• The fluid is not obligatory
Solution 1: 2-DoF shaking table on pressurized pipe
• Large stokes are required for full-scale specimens.
• Test velocity can be reduced
Solution 2: Bi-directional static loading on pressurized pipe
• Large strokes are available Full-scale specimens are allowed
• Test velocity can be increased
Possible setup
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ELSA setup: one actuator imposing ux at one end, another
actuator imposing uy at the other end.
Shake table setup: one end still, ux and uy imposed at the
other end.
Further analyses
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High temperature (500oC) creep ?
More accurate behaviour of the joint (friction, angular spring
constant, return moment, etc.)
Possible movements of the isolated part: tests/calculations output
more realistic differential displacement histories