Deteriorating Hysteresis Model for Cold-formed Steel Shear Wall Panel based on Physical and Mechanical Characteristics
1. Deteriorating Hysteresis Model for Cold-Formed Steel Shear Wall Panel Based on Physical and Mechanical Characteristics
OpenSeesDays Portugal 2014 – 4 July 2014
Smail Kechidi*, Nourdine Bourahla
University of Blida 1, Algeria.
*email: kechidi@hotmail.fr
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2. Outline of Presentation Introduction to Cold-Formed Steel Framing system Hysteresis model development Model validation Summary & Conclusions
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OpenSeesDays Portugal 2014 – OPD 2014
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Advantages : Lightness, Recycling, Easy Erection, etc.
Shear Wall Panel (SWP)
Cold Formed Steel framing (CFS) system
OpenSeesDays Portugal 2014 – OPD 2014
4. Other components:
Hold-down
Anchor rods (7/8”)
Shear bolts (3/4”)
Intermediate stud
Steel sheathing
Bottom track
Chord stud
Blocking
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OpenSeesDays Portugal 2014 – OPD 2014
Cold Formed Steel framing (CFS) system
• Steel sheathing/CFS frame shear wall panel
5. 5/22
PGA: 0.25
Max. displacement: 24.0 mm
OpenSeesDays Portugal 2014 – OPD 2014
Cold Formed Steel framing (CFS) system
• CFS shear wall panel behaviour
6. Objectives
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Development of a smooth hysteresis model for CFS SWP with parameters expressed explicitly in terms of SWP physical and mechanical characteristics
Hysteresis model implementation into OpenSees using a DLL named CFSSWP
Model validation through experimental test results
OpenSeesDays Portugal 2014 – OPD 2014
7. Hysteresis model CFSSWP
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CFSSWP deteriorating model can be used to simulate the CFS SWP lateral response when subjected to quasi-static or dynamic loading.
OpenSeesDays Portugal 2014 – OPD 2014
8. Hysteresis model CFSSWP
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Analytical methods for assessing the maximum lateral shear strength capacity of CFS SWP
Martinez (2007) for Wood sheathed CFS SWP
Yanari N. and Yu C. (2013) for Steel sheathed CFS SWP
• Backbone curve
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Comparison between monotonic test measurements and numerical model results
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B-Spline Algorithm
Hysteresis model CFSSWP
Wood sheathed SWP
Steel sheathed SWP
10. Hysteresis model CFSSWP
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• Hysteresis criteria
OpenSeesDays Portugal 2014 – OPD 2014
Monotone cubic spline Algorithm
11. Hysteresis model CFSSWP
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Comparison between monotonic and cyclic lateral response of CFS SWP
OpenSeesDays Portugal 2014 – OPD 2014
Wood sheathed SWP
Steel sheathed SWP
12. Hysteresis model CFSSWP
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Sc : Screw spacing (mm) ;
H et W : Height and Width of the CFSS SWP (mm), respectively.
OpenSeesDays Portugal 2014 – OPD 2014
• Deterioration criteria
13. Hysteresis model CFSSWP
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• Deterioration criteria
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14. C++ script of CFSSWP Hysteresis Model (CFSSWP.h)
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15. C++ script of CFSSWP Hysteresis Model (CFSSWP.cpp)
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OpenSeesDays Portugal 2014 – OPD 2014
18. Numerical results
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Comparison between test measurements and numerical model results of wood sheathed SWP
Specimen
H/W ratio (mm)
Wood type
Sheathing thickness (mm)
Screw spacing (mm)
Screw number
32
2440/2440
CSP
12.5
102
98
OpenSeesDays Portugal 2014 – OPD 2014
19. Numerical results
19/22
Comparison between test measurements and numerical model results of steel sheathed SWP
Specimen
H/W (mm)
ts (mm)
Fus (MPa)
Fys (MPa)
tf (mm)
Fus (MPa)
Fys (MPa)
Sc (mm)
Vs (N)
3C-a
2440/1220
0.46
391
342
0.87
395
300
150
1560
OpenSeesDays Portugal 2014 – OPD 2014
20. Conclusion
20/22
Hysteresis model has been developed where its parameters are related to the physical and mechanical characteristics of CFS SWP.
The model has been integrated into finite element software OpenSees as a user-defined uniaxial material using a DLL written in C++ programming language named CFSSWP.
The efficiency of the modeling tip and the accuracy of the proposed model have been proved by an acceptable correlation rate between the experimental and the analytical results in terms of shear strength-lateral displacement relationship, as well as the cumulative energy dissipation.
• Conclusions
OpenSeesDays Portugal 2014 – OPD 2014
21. Acknowledgment
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Mr. Omar Bourahla (USTHB University, Algeria) Dr. Iman Shamim (McGill University, Canada) Mr. Ribeiro Filipe (Nova University of Lisbon, Portugal)
OpenSeesDays Portugal 2014 – OPD 2014
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Thank you for your attention
OpenSeesDays Portugal 2014 – OPD 2014
Questions !