Presentation of the SOCRAT Benchmark
This page provide a brief description of the mock-up and its instrumentation, and of one of the exercices asked. As a member of the Benchmark and member of this website, you will have access to the full descrition and data needed.
Description of the overhead crane bridge mock-up
The mock-up is a simplified 1/5 scaled model of a 22.5 m long overhead crane bridge. The diferent components of the mock-up are shown below:
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Trolley
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Rails
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Wheels
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Girder beams
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End truck beams
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Runway beams
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Load cells (included in the supports between the shaking table upper plate and the crane bridge mock-up)

© CEA, Saclay, France



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As a member of the site and participant of the Benchmark, you will find all the information needed for the modeling of the mock-up on the page Members>The mock-up.
Exercices
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Different exercices are planned in order to characterize and calibrate the participants’ models, considering low and high seismic intensities signals, as well as hamer shock and white noise signals.
​Stage 1:
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Exercice 1 - Siffness of the load cell block A
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Exercice 2 - Runway beam 1
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Exercice 3 - Crane bridge mock-up
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Exercice 4 - Wheel/Rail interface
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Exercice 5 - Friction coefficient and damping ratio
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Exercice 6 - Local shocks parameters
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Exercice 7 - High level calibration
For instance, the exercice 2 is given:
Run #
Analyse Type
Input
Required Results
Exercice #2
Runway beam 1
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Modal analysis
Free-free condition
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Eigenfrequencies:
first four;
Eigenmodes:
(.png & vectors);
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Modal analysis
Fixed condition
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Eigenfrequencies:
first four;
Eigenmodes:
(.png & vectors);
17 (White noise signal)
Transient analysis
Axtab1
Acceleration: AxProule1H2;
Force:
Fx at supports A and B;
18 (White noise signal)
Transient analysis
Aytab1
Acceleration: AyProule1H2;
Force:
Fy at supports A and B;
19 (White noise signal)
Transient analysis
Aztab1
Acceleration: AzProule1H2;
Force:
Fz at supports A and B;
Girder beams
Girder beams are supporting the trolley. The provided
caracteristics are:
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Rectangular hollow section
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Length
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Distance between their central axes
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Young’s modulus
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Mass density
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Poisson’s ratio
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Yield stress

Instrumentation of the mock-up
The instrumentation dedicated to accelerations consists of 34 tri-axial accelerometers distributed on the mock-up and 4 tri-axial accelerometers on the shaking table, as follows:
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Intermediate plates of a load cell block : 6
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Base plates of the runway beams : 8
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Runway beam 1 : 8
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Runway beam 2 : 3
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End truck beams : 2
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Girder beam 1 and 2 : 6
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Trolley : 1
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Shaking table : 4
Runway beam 1
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Two tri-axial accelerometers are placed at the ends of the runway beam 1. Six tri-axial accelerometers are distributed along the runway beam 1 on its upper and lower faces, precisely on the internal side of the rail since the cheeks of the wheels are placed on the outer side of the rail.
2 Tri-axial accelerometers
AxProule1H0
AyProule1H0
AzProule1H0
AxProule1H4
AyProule1H4
AzProule1H4
First end of the runway beam 1
Second end of the runway beam 1
6 Tri-axial accelerometers
AxProule1H1 AyProule1H1 AzProule1H1
AxProule1H2 AyProule1H2 AzProule1H2
AxProule1H3 AyProule1H3 AzProule1H3
AxProule1H1 AyProule1H1 AzProule1H1
AxProule1H2 AyProule1H2 AzProule1H2
AxProule1H3 AyProule1H3 AzProule1H3
Upper face of the runway beam 1
Lower face of the runway beam 1
