Verification Test of a Hybrid Test System with Distributed Column Base Tests

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Verification Test of a Hybrid Test System with
Distributed ColumnBase Tests

• Tao Wang
• Jason McCormick
• Masayoshi Nakashima

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Substructure Online Hybrid Test System
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Difficulties in Collaboration

• Different software- or hardware- environment

• Modification of source code of FEM programs

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Outline

• Concept of the peer-to-peer (P2P) framework

• System implementation

Highly encapsulated substructures by Standard I/O
Multiple experimental/numerical substructures by
Coordinator
Incorporation of FEM programs without revising
source codes

• Demonstration test

• Summary

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Concept of Peer-to-Peer System

Partner
Partner


Coordinator

Partner
Partner
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Two Challenges for System Realization

• (1) How to determine the boundary displacement?
• Satisfy equilibrium and compatibility at boundary
• Only use standard I/O, i.e., boundary force
  displacement

• (2) How to avoid iteration for physical loading?
• One physical loading in one time step
• Compatibility with trial and error procedure

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Quasi-Newton Procedure
Procedures of Quasi-Newton Method
1. Equilibrium equation
2. BFGS iteration
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Predicting-Correcting Scheme
Wait
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Restart Option
Without restart
With restart
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Target Structure
Target Structure
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Substructures
Substructure 1
Substructure 3
Substructure 2
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Implementation for Testing Plastic Hinges
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Test Environment
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Specimens and Load Frames
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Input Ground Motion
Input Ground Motion (JR Takatori Station x 1.5)
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Displacement Responses
Story 1
Story 2
Story 3
Story 4
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Number of Iteration and Step Time
2.2
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1.2
Number of Iteration
Step Time
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Time Efficiency
Total
Superstructure
Left Column
Right Column
Coordinator
Exchange
2
0
4
5
8
(hours)
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Final State of Testing
Reaching stroke capacity at 19.12 sec!
Left Column Base
Right Column Base
Superstructure
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Axial Sustainability
Axial Deformation of Right Column Base
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Rotation Histories of Two Column Bases
Rotation Histories of Two Column Bases
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Axial Load Histories
Axial Load Histories
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Hysteretic Behavior of Left Column Base
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Hysteretic Behavior of Right Column Base
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Conclusions

• The P2P framework is able to handle multiple
  tested substructures, and it is demonstrated to
  be stable even though the tested substructures
  have significant unstable behavior.
• Collapse behavior of a steel moment frame is
  simulated reasonably using the P2P system.
  Significant deterioration at column bases is
  observed. The column bases sustained a varying
  axial force and survived after several cycles of
  large deformation up to 0.1 rad. It is also
  observed that the varying axial force affects the
  behavior of column bases significantly.