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2. AHSANULLAH UNIVERSITY OF SCIENCE
AND TECHNOLOGY
 COURSE NO : CE 450
 COURSE TITLE : PROJECT AND THESIS
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3. SUPERVISED BY:
Ms. SABREENA NASRIN
ASSISTANT PROFESSOR
DEPARTMENT OF CIVIL ENGINEERING
AHSANULLAH UNIVERSITY OF SCIENCE AND TECHNOLOGY
PRESENTED BY:
Faizah Ahsan Reza (11.01.03.009)
Wasi Uddin Ahmed (11.01.03.129)
Nusrat Khanum Zinia (11.01.03.157)
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THESIS TOPIC:
NUMERICAL SIMULATION OF CIRCULAR HOLLOW STEEL
COLUMNS CONFINED WITH FIBER REINFORCED POLYMER
UNDER AXIAL COMPRESSION

4. PROGRESS OF THIS PRESENTATION
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INTRODUCTION
LITERATURE REVIEW
FINITE ELEMENT MODELING
PERFORMANCE OF MODEL
CONCLUSION &
RECOMMENDATION

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INTRODUCTION
Why Steel Structure
is Preferred High Strength
Light Weight
Durable and Sustainable
Less Construction Period
Cost Effective
Easy to Replace
Easy to Retrofit
Scope of Further Extension

6. INTRODUCTION
Seismic Effect
Environmental Corrosion
Fatigue Failure
Major Concerns of Steel
Structures
Necessary Attempts :
o Innovation of Smart Techniques
o Easy Installation Process
o Long Lasting Materials
o High Performance Solution
Selection of
FRP
Laminates
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7. INTRODUCTION
 Easily Adjustable with Steel
 Effective in Restoring the Lost Capacity of a
Damaged Steel Section
 Strengthen the Steel Section
 Reduce the Probability of Crack Propagation
 Extend Fatigue Life
Why FRP is Chosen
Corroded Steel Column Laminating with FRP
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8. INTRODUCTION
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Objective
 To Develop a 3D Finite Element Model of a
Steel Column Confined with FRP Laminates
for Prediction of Compressive Behavior.
 To Validate the Numerical Results.
 To Find out the Effect of Different Parameters
like Slenderness Ratio.

9. Fiber Reinforced Polymer or Plastic
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INTRODUCTION
CFRP GFRP
AFRP
Types of FRP

10. LITERATURE REVIEW
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Column Strengthening with FRP
 The effective concept of constructing structure is to
implement strong column and weak beam. Application of
FRP laminates on steel column increases the ultimate
strength and improve the buckling effect.
 As a way of strengthening of steel column, repair of
corroded steel column, rehabilitation of fatigue damaged
steel structure, FRPs provide the increase in elastic
stiffness from 10 to 37 percent (Sarker et al 2006).
 Fatigue life of steel structure can also be extended by
using epoxy bonded FRP sheets and laminates.

11. FINITE ELEMENT MODELING
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Models Name Bare
Steel
Tube
Bare Steel
Tube with 1
ply FRP
Laminates
Bare Steel
Tube with 2
ply FRP
Laminates
Bare Steel
Tube with 3
ply FRP
Laminates
Outer Diameter(mm) 165 165 165 165
Length (mm) 450 450 450 450
Tube Thickness(mm) 4.2 4.2 4.2 4.2
FRP Thickness(mm) N/A 0.17 0.34 0.51
Dimensions of Simulated Model (Teng & Hu)

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FINITE ELEMENT MODELING
Geometric Modeling of Bare Steel Column
C3D8R Solid Element
3D Mesh View of Solid Element

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Geometric Modeling of FRP
S4R Shell Element
3D Mesh View of Shell Element
FINITE ELEMENT MODELING

14. Material Properties (Teng & Hu)
Property Values
Modulus of Elasticity 201 GPa
Yield Stress 333.6 MPa
Ultimate Strength 370 MPa
Elongation after fracture 0.347
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Steel
Property Values
Thickness (per ply) 0.17 mm
Modulus of Elasticity 80.1 GPa
Tensile Strength 1825.5 MPa
Ultimate Tensile Strain 0.0228
FRP
FINITE ELEMENT MODELING

15. FINITE ELEMENT MODELING
Material Properties`
Steel
FRP Laminate
Stress
Strain
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FINITE ELEMENT MODELING
Contact Surface
FRP will be used to retrofit the steel tube,
so a contact modeling will be needed. So
for this face to face contact surface was
created. The displacement portion is
created to Rigid Body.

17. Boundary Condition
Solution Strategy:
1. Newton-Raphson Method
2. Arc-Length Method
Displacement
Fixed
FINITE ELEMENT MODELING
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18. PERFORMENCE OF MODEL
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Combined Graph for Bare Steel Model

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PERFORMENCE OF MODEL
Combined Graph for Bare Steel Model Laminated with 1 Ply FRP

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PERFORMENCE OF MODEL
Combined Graph for Bare Steel Model Laminated with 2 Plies FRP

21. PERFORMENCE OF MODEL
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Combined Graph for Bare Steel Model Laminated with 3 Plies FRP

22. PERFORMENCE OF MODEL
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Combined Graph of All Models from Numerical Analysis

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Serial No Model Type Ultimate
Strength(KN)
Ultimate
Displacement(mm)
1 Steel Bare Model 698.844 6.00
2 Steel 1 Ply Model 799.774 15.00
3 Steel 2 Ply Model 820.517 15.00
4 Steel 3 Ply Model 830.517 15.00
Serial No FRP Ply Thickness
(mm)
Strength Ratio (fup/fub) Percentage of Strength
Gain
1 0.17 1.144 14.44%
2 0.34 1.174 17.41%
3 0.51 1.188 18.84%
PERFORMENCE OF MODEL
Gain in Strength

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Strength Ratio of Different FRP ply Thickness
PERFORMENCE OF MODEL

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SL
No.
Length
(mm)
Radius
(mm)
Slenderness
Ratio (L/rg)
Ultimate
Strength
(KN)
Ultimate
Displaceme
nt (mm)
Strength
Ratio
(fup/fub)
1 450 225 4.00 1992.290 0.756 1.01523873
2 450 82.5 10.90 799.774 15.00 1.14438735
3 450 45 20.00 381.517 3.875 1.03013134
Strength Ratio of Different
FRP ply Thickness
PERFORMENCE OF MODEL

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Parametric Study on Different Types of Strength Ratio with respect to
Different Types of Slenderness Ratio
PERFORMENCE OF MODEL

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Summary
The performance of finite element model in predicting the behavior of a variety
of FRP confined concrete columns under concentric loading in summarized as
follows
 The FE model developed in the study was observed to predict the
experimental peak quite accurately.
 The Static Riks solution strategy used in the finite element models made it
possible to trace the full behavior of confined columns without any
numerical difficulties.
 The interaction between the steel surface and FRP surface is successfully
modeled using contact pair algorithm.
PERFORMENCE OF MODEL

28. CONCLUSION
 A 3D Finite Element Model is developed to
investigate the axial compression behavior of FRP
confined steel column.
 The study is done by comparing the Stress vs. Strain
curves between numerical & experimental data.
 Parametric study is done to observe the variation of
strengths between bare and single ply FRP confined
models.
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29. RECOMMENDATIONS
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 Geometric imperfection was not included in the numerical simulation, so
it could have been better if geometric imperfection was provided.
 Softening Branch was created in the plastic zone of 4 models because
inward stress was greater than the outward one & also for experimental
setup.
 It was difficult to implement the overlapping the FRP part on the steel
body & so the desired result could not be found.

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 The parametric study was performed only for Slenderness Ratio (L/rg) in
only 1 ply condition. The study can also be done for varying thickness of
FRP and square hollow columns.
 Other parametric study like Overall Column Slenderness Ratio (L/d),
Load Eccentricity Ratio (e/d), Flange Plate Slenderness Ratio (b/t), Link
Spacing to Depth Ratio (s/d) etc can be done to see different changes of
strengthening.
 It can be a good recommendation in Seismic Retrofitting, Fatigue Failure
& Corrosion Resistance.
RECOMMENDATIONS

31. REFERENCES
 ABAQUS Analysis User’s Manual, v6.10.
 http://www.build-on-prince.com/aramid-
fibers.html#sthash.j80PxNy8.dpbs
 http://www.fassmer.de/wind-power/technologies/materials/cfrp/
 http://www.fassmer.de/wind-power/technologies/materials/gfrp/
 Teng * J.G., Y.M. Hu “www.pipemedic.com_pdfs_behaviour-of-FRP-
jacketed-circular-steel-tubes-and-cylindrical-shells-under-axial
compression”, 2006, Construction and Building Materials 21 (2007)
827–838.
 Sarker P., Mahbuba Begum and Sabreena Nasrin, “Fiber reinforced
polymers for structural retrofitting: A review, Journal of Civil
Engineering (IEB), 39 (1) (2011) 49-57.
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Questions & Answers
Session

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