International Journal of Scientific Research Engineering & Technology (IJSRET), ISSN 2278 – 0882
Volume 4, Issue 3, March 2015
FLEXURAL BEHAVIOUR OF TRAPEZOIDAL CORRUGATION
BEAM BY VARYING ASPECT RATIO
R.S.Priyanga1, J.Mathivathani2, and A.Venkatesan3
UG student, Department of civil engineering, Panimalar engineering college
4
Asst.Professor, Department of civil engineering, Panimalar engineering college,
Chennai, Tamilnadu, India.
1, 2,3
ABSTRACT
The use of cold formed steel structures is
increasing throughout the world as they are efficient in
terms of stiffness and strength. The use of thinner
sections and high strength steel leads to design problems
for structural engineers who may not normally
encountered in routine structural steel design. Structural
instability of the section is more likely to occur. To
improve their strength and to eliminate local buckling of
web elements, trapezoidal corrugated web is used.
Totally 10 Specimens were investigated out of which,
four specimen by varying aspect ratio from 0.5 to 2. And
remaining specimens were investigated by varying the
corrugation angle from 0° to 90°.with an increment of
15°. Keeping all other parameters constant. Using a
finite element package ANSYS all the Specimens were
modeled and analyzed. Non linear analysis was carried
out. From the analysis critical load was calculated by
using the Load Vs Deflection curve. By using the
“Australian / New Zealand standard AU/NZS
4600:2005” and “North American Specification
Standards for Cold formed steel Design AISI S100:2007
the theoretical calculation of load was carried out. The
results from numerical, theoretical investigation were
compared and presented.
States and U.K. However, such steel members were not
widely used in buildings until 1940. In the recent years,
it has been recognized that cold-formed steel sections
can be used effectively as primary framing components.
In what concerns cold-formed steel sections, after their
primarily applications as purling or side rails, the second
major one in construction is in the building envelope.
Options for steel cladding panels range from inexpensive
profiled sheeting.
2. OBJECTIVE
Specific objectives of this research are as
follows: To investigate the behavior of cold formed
corrugated I beam with varying the aspect ratio (a/b) and
angle of trapezoidal corrugation. To obtain experimental
data of section and member capacities of the trapezoidal
corrugated I section subjected to two point load. To
determine the maximum load carrying capacity of the
specimens by using North American Specification
standards, And Australian / New Zealand standard
4600:2005To analyze the results of the experimental test
in comparison with theoretical calculation and with
numerical analysis using ANSYS. To study the possible
modes of failure of the members under static loading.
3. NEED FOR STUDY
KEYWORDS: ANSYS, AU/NZS, trapezoidal corrugated
web, critical load.
1. INDRODUCTION
Cold-formed steel products are found in all
aspects of modern life; in the home, the shop, the
factory, the office, the car, the petrol station, the
restaurant, and indeed in almost any imaginable location.
The uses of these products are many and varied, ranging
from “tin” cans to structural piling, from keyboard
switches to mainframe building members. Nowadays, a
multiplicity of widely different products, with a
tremendous diversity of shapes, sizes, and applications
are produces in steel using the cold forming process. The
use of cold-formed steel members in building
construction began in about the 1850s in both the United
Corrugated web beams are built up one with a
thin walled corrugated web and two flanges connected
by welding. A thin web may be sufficient to take care of
shear stresses developed due to external loads, but
sometimes thin web shows instability and hence
stiffeners are necessary to account for such type of
stability problems. Instead of using stiffeners,
corrugation in the web portion is created. This situation
leads to the corrugation in web. The corrugated web due
to its profile shows more stiffness than flat web. Beams
with corrugated webs have been used in buildings and
have been proven to be economical. The use of
corrugated webs allows for the use of thin plates without
the need for stiffeners. The use of corrugated webs is a
potential method to achieve adequate out-of-plane
stiffness and shear buckling resistance without using
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170
International Journal of Scientific Research Engineering & Technology (IJSRET), ISSN 2278 – 0882
Volume 4, Issue 3, March 2015
stiffeners. Thus it considerably reduces the cost of the
beam fabrication and improves its fatigue life. It could
eliminate the usage of larger thickness and stiffeners that
contributed to the reduction in beam weight and cost.
The use of corrugated webs will increase the lateral
stiffness of the beam
Nodes or Nodal points. This method of analysis has an
advantage of that it can take care of any boundary and
loading conditions.
4. PROPOSED WARPING CONSTANT
The warping constant can be determined by
considering the section to be composed of a series of
interconnected plate elements with lipped section shown
in Fig. No. (3.1) and shear flow of the corrugated web
also shown in Fig.No.3.2.before study by “Lateral
torsional buckling of I- girder with corrugated webs
under uniform bending” by “ Jiho Moon, Jong-Won yib,
Byung H.Choic, Hak-Eun Lee” proposed the warping
constant for without lip. In this study, the proposed
warping constant for trapezoidal corrugation in web by
lipped I-beam was evaluated. Using the proposed
methods, the lateral-torsional buckling strength of lipped
I-beam with trapezoidal corrugation webs can be
calculated easily.
Wn1= (bf/2-2d)*bl
+(bf*hw/4)
Wn3 = d*hw/2
Wn5 = -wn2
Wn7 = -wn1
Wn2 = bf*hw/4
Wn9 = wn2
Wn10 = wn1
Wn4 = -wn3
Wn6 = -wn4
Wn8 = -wn2
A.Global buckling
B.Flexural buckling mode
Average Corrugation Depth davg
davg = ((2a+b) / 2(a+b))*dmax
Determination of Warping Constant for (CFS)
Trapezoidal Corrugation lipped I beam varying depth of
web.
Cw,co = 1/3∑ (W2ni + Wnj*Wni + W2nj)tijLij mm6
valuation of Normalized Unit Warping for an Element
5. NUMERICAL ANALYSIS
The finite element method is a numerical
analysis technique for obtaining approximate solutions
to wide variety of Engineering problems. Most of the
engineering problems today make it necessary to obtain
approximate numerical solutions to problems rather than
exact closed form solutions. The basic concept behind
the finite element analysis is that structure is divided into
a finite number of elements having finite dimensions and
reducing the structure having infinite degrees of freedom
to finite degrees of freedom. The original body of
structure is then considered as an assemblage of these
elements connected at a finite number of joints called
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Deformation of specimen TCIAE 1
171
International Journal of Scientific Research Engineering & Technology (IJSRET), ISSN 2278 – 0882
Volume 4, Issue 3, March 2015
COMPARISON OF LOADS
Aspect ratio
Load carrying
capacity
(kN)
TCWAR 1
0.5
43.72
TCWA 4
1.0
TCWAR 2
1.5
TCWAR 3
2.0
Specimen ID
TCIAE 1 - Load Vs Deflection curve
6. FINITE ELEMENT ANALYSIS RESULTS
Specimen
Name.
Corrugati
on angle
Failure
Load
(kN)
Failure
Mode
TCIAE - 1
15°
32.69
Lateral
buckling
TCIAE - 2
30°
33.75
TCIAE - 3
45°
35.19
TCIAE - 4
60°
33.58
44.89
44.68
44.60
COMPARISON OF AISI S-100-2007
RESULTS
Lateral
buckling,
crushing of
compressio
nLateral
flange
torsional
buckling
Lateral
torsional
buckling
Corrugation
angle
Load
carrying
capacity
(kN)
TCWA 1
0°
40.38
TCWA 2
15°
44.54
TCWA 3
30°
44.71
TCWA 4
45°
44.89
TCWA 5
60°
45.06
TCWA 6
75o
45.17
TCWA 7
90o
45.21
Specimen ID
7. COMPARISON OF FEA RESULTS
RESULTS AND DISCUSSIONS
The load carrying capacities of specimens,
estimated by using North American Specification
Standards, theoretical analysis is compared with the
Numerical Analysis & experimental failure load.
Discussions were carried out with respect to the load
carrying capacities and the failure mode occurred. From
the analysis critical load was calculated by using the
Load Vs Deflection curve. By using the “Australian /
New Zealand standard AU/NZS 4600:2005” and “North
American Specification Standards for Cold formed steel
Design AISI S100:2007 the theoretical calculation of
load was carried out. The results from numerical,
theoretical investigation were compared.
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172
International Journal of Scientific Research Engineering & Technology (IJSRET), ISSN 2278 – 0882
Volume 4, Issue 3, March 2015
Theoretical Load Carrying Capacity as Per AISI S100: 2007
Load
Corrugation
carrying
Specimen ID
angle
capacity
(kN)
TCWA 1
0°
40.38
TCWA 2
15°
44.54
TCWA 3
30°
44.71
TCWA 4
45°
44.89
TCWA 5
60°
45.06
TCWA 6
75o
45.17
TCWA 7
90o
45.21
Comparison of Theoretical Investigation
Theoretical Load Carrying Capacity as per
Australian / New Zealand standard 4600:2005
Load carrying
capacity
Specimen ID Corrugation angle
(kN)
Comparison of Theoretical Investigation
TCWA 1
0°
TCWA 2
15°
43.20
TCWA 3
30°
43.29
TCWA 4
45°
43.45
TCWA 5
60°
43.61
TCWA 6
75°
43.72
TCWA 7
90°
43.76
41.25
Theoretical Load Carrying Capacity as per
Australian / New Zealand standard 4600:2005
Specimen
ID
Aspect
ratio
TCWAR 1
0.5
TCWA 4
1.0
TCWAR 2
1.5
TCWAR 3
2.0
Load carrying
capacity (kN)
43.04
43.45
43.89
43.84
Comparison of Theoretical Investigation
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International Journal of Scientific Research Engineering & Technology (IJSRET), ISSN 2278 – 0882
Volume 4, Issue 3, March 2015
8. DISCUSSIONS
`From the above table of the theoretical results
when the angle of corrugation increases the load
carrying capacity of the specimen increases..In table 2,
from the numerical results it is observed that the angle
of corrugation increases the load carrying capacity
increases. But in Numerical & theoretical analysis the
load carrying capacity is maximum when the
corrugation angle is 45°.The ratio between the
theoretical load to the numerical load PT/PN Mean Value
= 1.03 Standard Deviation = 0.005.From which it is
observed that theoretical and Numerical results are in
good agreement. Similarly the ratio between the
numerical load to the theoretical load PN/PT .Mean Value
= 1.07.Standard Deviation = 0.033.All the specimens
fails due to lateral torsional buckling. Failure in the web
is eliminated due to provision of corrugation in web.
Bearing failure is eliminated due to the provision of
stiffeners at the loading points and supports.
9. CONCLUSION
The designed beam were analyzed using ansys
software and the results were holds good with
theoretical investigation and the behavior are same
when compared with numerical analysis. In the
theoretical investigation as corrugation angle increases,
the load carrying capacity increase. In the numerical
analysis also as corrugation angle increases, the load
carrying capacity increases. From the numerical and
theoretical analysis the load carrying capacity is
maximum in 45̊ .All the specimen fails due to lateral
torisional buckling
REFERENCES
1. Johnson R.P., J. Cafolla, “Local flange buckling in
plate girders withcorrugated webs”, in: Proceedings of
the Institution of Civil Engineers, Structures and
Buildings, vol. 122, No. 2, 1997, pp. 148–156.
2. Johnson R.P., J. Cafolla, “Corrugated webs in plate
girders for bridges”, Proceedings of the Institution of
Civil Engineers, Structures and Buildings, vol. 122, No.
2, 1997, pp. 157–164.
3. Moon J, Yi J, Choi BH, Lee HE. “Lateral_torsional
buckling of I-girder with corrugated webs under uniform
bending”. Thin Walled Struct 2008
4. Schafer, B.W., Peköz, T. (1999). “Laterally Braced
Cold-Formed Steel Flexural Members with Edge
Stiffened Flanges.” Journal of Structural Engineering.
125(2).
5. Samanta A, Mukhopadhyay M. “Finite element static
and dynamic analyses of folded plates”. Eng Struct
1999;21:227-87.
6. Sayed-Ahmed E. Y. PhD, MSc, MCSCE, MIABSE.
“Lateral torsion-flexure buckling of corrugated web steel
girders”. Proceedings of the Institution of Civil
Engineers Structures & Buildings 158 February 2005
Issue SB1 Pages 53–69 Paper 13351.
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