Deteriorating Hysteresis Model for Cold-formed Steel Shear Wall Panel based on Physical and Mechanical Characteristics

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: [email protected] 1/22

Outline of Presentation Introduction to Cold-Formed Steel Framing system Hysteresis model development Model validation Summary & Conclusions

2/22

OpenSeesDays Portugal 2014 – OPD 2014

3/22

Advantages : Lightness, Recycling, Easy Erection, etc.

Shear Wall Panel (SWP)

Cold Formed Steel framing (CFS) system


Other components: Hold-down Anchor rods (7/8”) Shear bolts (3/4”)

Intermediate stud

Steel sheathing

Bottom track

Chord stud

Blocking

4/22



• Steel sheathing/CFS frame shear wall panel

5/22

0 10 20 30Time (sec)

-0.4

-0.2

0

0.2

0.4

Ea

rth

qu

ake

acce

lera

tio

n,

Qu

eb

ec (

g)

PGA: 0.25Max. displacement: 24.0 mm

0 1 2 3 4Period (sec)

0

0.2

0.4

0.6

0.8

1

Sa

(g

)-lin

ea

r (

5)

UHS for Quebec (soil class C)

Closely matched record

0 1 2 3 4Period (sec)

0

0.02

0.04

0.06

0.08

Po

we

r sp

ectr

um

, Q

ue

be

c

a)

b) c)



• CFS shear wall panel behaviour

Objectives

6/22

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


Hysteresis model CFSSWP

7/22

CFSSWP deteriorating model can be used to simulate the CFS SWP lateral response when subjected to quasi-static or dynamic loading.



8/22

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


9/22

Comparison between monotonic test measurements and numerical model results


B-Spline Algorithm


Wood sheathed SWP Steel sheathed SWP


10/22

• Hysteresis criteria


Monotone cubic spline Algorithm


11/22

Comparison between monotonic and cyclic lateral response of CFS SWP


Wood sheathed SWP Steel sheathed SWP


12/22

Sc : Screw spacing (mm) ;

H et W : Height and Width of the CFSS SWP (mm), respectively.


• Deterioration criteria


13/22

• Deterioration criteria


C++ script of CFSSWP Hysteresis Model (CFSSWP.h)

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C++ script of CFSSWP Hysteresis Model (CFSSWP.cpp)

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Hysteresis model validation

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• Modelling of the CFS SWP

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Hysteresis model validation

• Loading protocol

Numerical results

18/22

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


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


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


Acknowledgment

21/22

Mr. Omar Bourahla (USTHB University, Algeria) Dr. Iman Shamim (McGill University, Canada)

Mr. Ribeiro Filipe (Nova University of Lisbon, Portugal)


22/22

Thank you for your attention


Questions !

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Deteriorating Hysteresis Model for Cold-formed Steel Shear Wall Panel based on Physical and Mechanical Characteristics