This project explains the flexural strength behavior of the thin walled steel channel section by the eccentrically loading (shear center).

1. Flexural strength performance
of thin steel plain and slotted
channel sections
Presented By : Guide:

2. CONTENTS :
ABSTRACT
INTRODUCTION
OBJECTIVES
SCOPE
LITERATURE
CODE OF PRACTICE FOR USE
METHODOLOGY
i) FLOW CHART
ii) ANALYTICAL METHOD
iii) EXPERIMENTAL METHOD

3. RESULTS AND DISCUSSIONS
i. EXPERIMENTAL RESULTS
ii. THEORETICAL RESULTS
iii. THEORETICAL vs EXPERIMENTAL
 CONCLUSION
REFERENCES

4. ABSTRACT :
 This project explains a methodology that would enable the
development of optimized CFS beam section with maximum
flexural strength for practical applications.
 One specimen with plain and one specimen with slotted
channel sections were tested in single point bending.
The advantage of the CFSS is becoming so interesting in
selecting it as a roof truss system and purlins.
 Cold formed steel sections can be optimized to increase
their load carrying capacity, leading to more efficient and
economical structural system.
 The experimental and analytical results, which indicates that
the plain channel exhibits more strength compared to slotted
channel section.
 This report presents results of an experimental investigation
on flexural strength of cold-formed steel, plain and slotted
channel sections.

5. INTRODUCTION :
 Results of an experimental investigation flexural
strength of cold formed steel plain and slotted
channel sections are studied.
 Cold-formed steel section (CFSS) is a civil engineering
material that still and always in ongoing research for
utilizing building.
 One of the recent developments in the field of steel
construction is cold-formed sections (CFS)
 One of the most common cold-formed steel shape is
C-sec which can be used for roofing ,framing
partition ,purlins and many more .
 To provide reliable and efficient cold-formed steel
structures the performance of the C-section can be
predicted by using bending test.

6.  Flexural test has been used to determine flexural
strength
 Analytically the strength can be calculated by using
Effective Width Method (EWM) based on F.O.S method.
 CFS section have many advantages due to the
characteristic of material ,high stiffness and strength,
lightness, accurate detailing and uniformity of sections.
 Special benefit of the CFS sections in building
construction related to the easy to handle due to
sufficiently light material ,compact packing and shipping
which also allowed to be fast and easy erection
installation.
 Having all the advantages of the CFS as a structural
members therefore ,CFS material have been increasingly
used for many constructions.

7.  There for ,design specifications and guidelines are
essentially required to meet the strength design
requirement for CFS structural member.
 The CFS has relatively high strength which the yield stress
specified up to 250mpa.
 Typical channel section can be seen in fig 1 (as per IS 811-
1987)
Web Depth (d) Ranges from 30mm to 250mm.
Thickness of section (t) Ranges from
1.15mm to 5.00mm.
Width of Flange (b) Ranges from 15mm to 80mm.
Depth of Lip (c) Ranges from 10mm to 25mm.
International Radius at curve (R) ranges from 1.88mm
to 7.50mm.

9.  However, it provides different behavior and different
failure mode due to the section of CFS is much thinner
than hot-rolled sections.
 Local instability of thin-walled sections used to be an
issue of the CFS , deformations and small change in
geometry has significantly altered the strength of
normal condition .
 How ever it is not generally lead to failure due to the
help of post-buckling strength provided by the sections.
 This means that the CFS capable of carrying loads
beyond the expectation which is higher even after the
local buckling occurred with in the structural members .

10. OBJECTIVES :
The objective of this experiment is to study the deflection
during flexural strength of CFS
The intent is to compare analytical experimental results of
flexural strength of cold-formed steel channel section
The sectional capacity were analysed by using effective
width method (EWM) with and with out factor of safety
SCOPE :
• To get familiarizing with code of practice
• Selecting channel section as per availability in the market
and as per suitability of laboratory
• Finding the failure load by the analytical method calculations
• Finding the failure load by the experimental method by
proper setup
• Finally Comparing both the analytical and experimental
results of the plain and slotted channel sections

11. LITERATURE:
 Development of more efficient cold formed steel
channel sections in bending
junye, iman hajira souliha, jurgen becque, kyprous
pilakoutas
• The literature aims to provide a methodology that
would enable the development of optimised CFS beam
section with maximum flexural strength for practical
application.
 Experimental investigation of cold-formed steel
channels with slotted web in shear
N.V.Degatyareva, V.V.Degtyarev
• This literature presents results of an experimental
investigation on shear strength of cold-formed steel
channels with slotted webs
• Specimens with slotted webs and solid webs were
tested in one point bending.

12. Flexural strength performance and buckling mode
prediction of cold-formed steel C-sectionn
Adi.susila, jimmy tan
• This literature presents results on flexural strength
analytically the strength can be calculated by using
effective width method.
Experimental investigation of buckling length of CFS
lipped channel beams under restrained boundary
conditions
R.kanda swamy , R.thenmozhi
• This literature presents the experimental investigation has
been carried at to verify the coefficients for the definite
boundary conditions
• The influence of flange width and lip size on the buckling
length has been investigation the result are compared with
IS Code provision.

13. CODE OF PRACTICE FOR USE:
 IS : 801-1975 (Reaffirmed 2010)
COLD-FORMED LIGHT GAUGE STEEL STRUCTURAL
MEMBERS IN GENERAL BUILDING CONSTRUCTION
 IS : 811-1987 (Reaffirmed 2004)
SPECIFICATION FOR COLD FORMED LIGHT GAUGE
STRUCTURAL STEEL SECTIONS
 IS : 800-2007
GENERAL CONSTRUCTION STEEL
METHODOLOGY :

14. FLEXURAL STRENGTH
PERFORMANCE OF
THIN STEEL PLAIN AND
SLOTTED CHANNEL
SECTIONS
FAMILIARRIZING WITH
CODE OF PRACTICE
CHECK ON THE AVAILABILITY
OF THE SECTION

15. DESIGN PROCEDURE
AS PER IS:801 FOR
FLEXURAL MEMBERS
FAILURE LOAD ASSESSMENT
DEDUCTION FROM DESIGN
PROCEDURE
TEST ON CHANNEL
SECTION

16. COMPARISION OF RESULTS
CONCLUSION
ANALYTICAL METHOD

17. Determine the allowable Bending Moment for C-lipped
channel section as shown in the figure?
STEP 1:-
Get “w” and “h” and lip height
w = 6-(02+2(0.20))
w = 6-(0.2+0.4)
w = 6-0.6
w = 5.4 cm
h = 20(0.2 + (2x0.2))
h = 20-0.6
h = 19.4 cm
lip height h = 2-(0.2+0.2)
h = 2-0.4
h = 1.6 cm

18. ELEMENTS AREA “A”
(cm ̂ 2)
Fy distances
from N.A
Ay(cm ̂4) Ig = (cm ̂ 2)
FLANGES
2x5.4x0.2
= 2.16
10-0.1
= 9.9
211.7016
2x1/12x5.4x0.2 ̂
3
=0.0072
CORNERS
2x1.57x0.2x0.2
= 0.1256
10-0.2-0.2+
(0.637x0.2)
= 9.7274
11.8845
4x0.149x0.2 ̂3
= 4.768x10 ̂-3
=0.004768
WEBS
1x19.4x0.2
= 3.88
20-10-10
= 0
0
1x1/12x0.2x19.4
̂3
=121.6897
LIP
2x1.6x0.2
= 0.64
10-0.2-0.2-0.8
= 8.8
49.5616
2x1/12x0.2x1.6 ̂
3
=0.1365
∑ A=6.8056 ∑Ay ̂ 2
=273.14
∑Ig =121.838
STEP 2:-
Sectional properties

19. = 273.1477 + 121.8382
Ixx = 394.985
Zxx =
=
Zxx = 39.498599
STEP 3:-
Calculating the allowable stress
=

20. Since
Fc = Fy
=
Fc = 860.585 kg/
STEP 4:-
Note allowable stress from Table 2
M = Zxx X Fc
= 39.4985 x 860.585
M = 33991.90241 kg/m

21. STEP 5:-
Failure load finding by using Fy
B.M = Fy X Zxx
B.M =
B.M = 1006.933 Kg m
Finding load carrying capacity of channel
W x 2.5 =1006.933 x 4
=
=
W = 1611.0941 kg
STEP 6:-
Finding Shear Gravity

22. C =
=
C = 1.66cm
(or)
e =
e =
e = 1.84cm
EXPERIMENTAL METHOD :
LOAD CELL OF 20 TONE OF CH-11

23. FIXING THE LOAD CONNECTIONS

24. PLANE CHANNEL SECTION
SLOTTED CHANNEL SECTION

25. SETTING AND LOADING ON PLAIN CHANNEL SECTION

26. SETTING AND LOADING ON SLOTTED CHANNEL SECTION

27. 20CH DATA
LOGGER UNIT -1
LINEAR VARIABLE
DIFFERENTIAL
TRANSFORMER (LVDT)

28. EXPERIMENTAL RESULTS :
LOAD (TONNE) DEFLECTION (mm)
0.1 1.641
0.2 3.094
0.3 3.262
0
0.5
1
1.5
2
2.5
3
3.5
0 0.1 0.2 0.3 0.4
DEFLECTION(mm)
LOAD (TONNE)
Load vs Deflection for plain channel section

29. LOAD (TONNE) DEFLECTION (mm)
0.05 0.305
0.1 0.703
0.15 2.300
0.2 2.400
Load vs Deflection for slotted channel section
0
0.5
1
1.5
2
2.5
3
0 0.05 0.1 0.15 0.2 0.25
DEFLECTION(mm)
LOAD (TONNE)

30. THEORETICAL RESULTS
Finding Deflection for a simply supported beam by
central loading
FOR PLAIN CHANNEL SECTION
SIMILARLY FOR SLOTTED ALSO
mm
= 0.842mm
= 1.236mm

31. LOAD (TONNE) DEFLECTION (mm)
0.1 0.412
0.2 0.841
0.3 1.236
Load vs Deflection for plain channel section
0
0.2
0.4
0.6
0.8
1
1.2
1.4
0 0.1 0.2 0.3 0.4
DEFLECTION(mm)
LOAD (TONNE)

32. LOAD (TONNE) DEFLECTION (mm)
0.05 0.206
0.1 0.412
0.15 0.618
0.2 0.841
Load vs Deflection for slotted channel section
0
0.2
0.4
0.6
0.8
1
0 0.05 0.1 0.15 0.2 0.25
DEFLECTION(mm)
LOAD (TONNE)

33. THEORETICAL vs EXPERIMENTAL
0
0.5
1
1.5
2
2.5
3
3.5
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35
DEFLECTION(mm)
LOAD (TONNE)
EXPERIMENTAL vs THEORETICAL
EXPERIMENTAL
THEORETICAL
FOR PLAIN CHANNEL SECTION
FOR SLOTTED CHANNEL SECTION
0
0.5
1
1.5
2
2.5
3
0 0.05 0.1 0.15 0.2 0.25
DEFLECTION(mm)
LOAD (TONNE)
EXPERIMENTAL vs THEORETICAL
EXPERIMENTAL
THEORETICAL

34. CONCLUSION
The results show that the plain channel specimen has deflection up to
0.3tone beyond that torsion occurs.
The experimental deflection for 0.3tone is 3.262 mm and the theoretical
deflection for 0.3tone is 1.236mm.
This shows that our specimen behavior is not as per the standards.
For the slotted channel specimen section the flexural deflection is up to
0.2tone and beyond 0.2tones the torsion mode of deformation occurs
hence the flexural deflection could not be recorded.
The experimental deflection for 0.2tone is 2.400mm and the theoretical
deflection for 0.2tone is 0.841mm.
This shows that our specimen behaviour is torsionally very weak .
This shows that the plain channel specimen has better load capacity
compared to slotted channel specimen.

35. REFERENCES
1) T.Hoglund,H.Burstrand,Slottedsteel studs to reduce thermal
bridges in insulated walls ,Thin-Walled Struct.32(1998)81-
109.
2) L.Fiorino,O.Luorio,R.landolfo,Designing CFS structures :the
new school bfs in naples ,Thin Wall Struct.78(2014)78-94.
3) John T.DeWOLF and Clinton J.Gladding (1978), “Journal of
the Structural Division, Post Buckling Behaviour of Beam
Webs in Flexure”, Vol.104, No.ST7,pp 1109-1122.
4) R. A. L. Wei – Wen Yu ,Cold –Formed Steel Design : JOHN
Wiley &Sons,INC.,2010
5) T. M. M. Gregory J.hancock, Duane S. Ellifritt, Cold –Formed
Steel Structures to the AISI Specification . New-York :Marcel
Dekker,2011.