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International Journal of Advance Engineering Science & Technology Vol 1, Issue 1, January 2018, pp. 55-58 ISSN xxx-yyy © MIT Publications
Load Carrying Capacity of Indian Standard Steel I-Section Adil Ata Azmi1, Mohd. Reyaz Ur Rahim2 2
1 Department of Civil Engineering, Integral University, Lucknow (U.P.) 226026, India. Department of Mechanical Engineering, Integral University, Lucknow (U.P.) 226026 , India.
provides higher strength per unit weight when compared to concrete r any other conventional material. As it possesses high strength lesser amount of material is require to bear a given load thus it also helps in increasing the aesthetical appearance of the structure.
Abstract: Steel is one of the materials of the construction industry that is fast becoming popular due to its desired properties like high strength, ease of assembly, construction and reusability. Also, it offers higher strength per unit mass as compared to concrete. The most common section that’s being used is the I section it’s commonly used in both beams and columns as well. Thus this paper analyzes the behavior of the I section beams of the Designation IS 150, IS 175, IS 200, IS 225. Under these designations further, the analysis is carried out on JB (Junior beams), LB (Light beams), MB (Medium Beams), WB (Wide Flange beams), HB (High Beams). All the analysis has been carried out using the Static structural and linear buckling module of ANSYS 15.0.
It has been observed that the value of the critical load varies with the variation in the cross-section of the structure [5-7]. One such geometry that appreciably resists the buckling load is an I-section. Due to its behavior the I-sections are extensively used in the construction of beams as well as columns. This paper is an attempt to analyze the buckling load of the various I section of the Indian standard code and the standard steel table [8].The analysis has been carried out using the linear buckling module of ANSYS 15.0 [9]. The length of the specimen is made fixed at 1200mm while the variation has been carried out in the height , breadth and the thickness of the web and flanges. The flanges of an I section generally resists the bending while the web portion resists the shear action.
Keywords: Buckling load, I-section beam, numerical modelling
I.
INTRODUCTION
Steel structures are being widely used in constructional and other fields of study like construction of bridges ,Railway over bridges, viaducts, Walkovers train engines Buckling behavior and energy absorption of steel structure have been widely used and analyzed.[1-4].Building design consists of two parts one part deals with the aesthetical aspects of the building like orientation while the other parts deals with the structural aspects of the building and theses requires the use of material and workmanship. Under the heading of structural detailing there are various materials that are being used like bricks, concrete, mortar, asphalts, cement blocks, steel ,etc. Steel is one of the most widely used materials in the constructional industry because of its exceptional behavior such a high resistance towards tension and good resistance to compression. It
II. METHODOLOGY All the specimen dimensions have been made according to the IS code 800:2007 [10].As well as the standard steel table. The standard length of the specimen has been taken as 1200 mm. While the variation has been done on the height, Breadth and thickness of the flange, Depth and thickness of the flange. The bottom end of the section is restrained in all the direction while the other end is kept free and the load is applied at the free end. All the specimens were analyzed while taking structural steel as the material of the specimen having the following properties. Density 7.85x10-6 kg/mm3 Young’s modulus 200Mpa poisons ratio 0.3 and 250Mpa yield strength ultimate strength as 460Mpa.
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International Journal of Advance Engineering Science & Technology Vol 1, Issue 1, January 2018, pp. 55-58 ISSN xxx-yyy © MIT Publications
Fig A: Specimen support conditions
Fig B: Deformation at the free end
Fig C: Deformation near the fixed end as well as the free end.
III. RESULTS AND DISCUSSIONS a ) Variation in Junior Beam: The junior beams are the lightest and among the cheapest of the Indian standard beams and are generally used for light works such as supporting of sun shades. The buckling load constantly increases with the increase in the designation of the steel from ISJB 150 to ISJB 225.
Buckling load (105 N)
1
b) Variation in Light Beams: Light beams are able to withstand much more buckling load than the junior beams for the same height of the section. The buckling load increases consistently from ISLB 150 to ISLB 225. c) Variation in Medium Beam:
0.8
ISJB 150 @ 69.7 N/m
0.6
ISJB 175 @ 79.5 N/m
0.4
ISJB 200 @ 97.1 N/m
0.2
ISJB 225 @ 125.6 N/m
0 INDIAN STANDARD JUNIOR BEAMS
The medium beams are even more resistant to buckling load than that of light beams for the same height and the variation is also quite constant from ISMB 150 to ISMB 225.
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International Journal of Advance Engineering Science & Technology Vol 1, Issue 1, January 2018, pp. 55-58 ISSN xxx-yyy © MIT Publications
ISMB 150 @ 146.2 N/m
5 4
ISMB 175 @ 189.3 N/m
3 2
ISMB 200 @ 249.2 N/m
1
ISMB 225 @ 306.1 N/m
0 INDIAN STANDARD MEDIUM BEAMS
Buckling load (105 N)
Buckling load (105 N)
6
9 8 7 6 5 4 3 2 1 0
ISWB 150 @ 166.8 N/m ISWB 175 @ 216.8 N/m ISWB 200 @ 282.5 N/m ISWB 225 @ 332.6 N/m INDIAN STANDARD WIDE FLANGE BEAMS
ISHB 150 @ 339.4 N/m ISHB 200 @ 365.9 N/m ISHB 200 @ 392.4 N/m ISHB 225 @ 422.8 N/m ISHB 225 @ 459.1 N/m
10 8 6 4 2 0 INDIAN STANDARD HIGH BEAMS
Comparision of buckling load of various section I section beams
ISJB Buckling Load (105 N)
Buckling load (105 N)
12
12 10 8 6 4 2 0
ISLB ISMB ISWB ISHB 150
175
200
225
Buckling load (105 N)
3.5
ISLB 150 @ 139.9 N/m
3 2.5
ISLB 175 @ 163.8 N/m
2
ISLB 200 @ 194.2 N/m
1.5 1
ISLB 225 @ 230.5 N/m
0.5 0 INDIAN STANDARD LIGHT BEAMS
d) Variation in Wide flange Beams:
e) Variation in High Beams: The High beams are the best pre-fabricated I section from the Indian standard code and best in resisting the shear as well as the ending stresses among all the pre-fabricated sections. But the variation is quite different than the rest of the sections. The buckling load first increases and fails only with bending at the top [Figure B]. Then at ISHB 200 the buckling load decreases and the
The wide flange beams are especially designed with wide flanges and are extensively used at places where the structure is supposed to be under high bending stresses. The buckling load increases smoothly from ISMB 150 to ISMB 225.
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International Journal of Advance Engineering Science & Technology Vol 1, Issue 1, January 2018, pp. 55-58 ISSN xxx-yyy © MIT Publications
buckling load again increases. All the variations in
member distorts near the fixed end and it also deforms from the free end [Figure C]. From here the the I-section beams have been tabulated in the Table 1.
Table-1 cimen
Height of I section
Buckling load (105 N)
ISJB 150 @ 69.7 N/m ISJB 175 @ 79.5 N/m ISJB 200 @ 97.1 N/m ISJB 225 @ 125.6 N/m
150 175 200 225
0.21074 0.22017 0.39577 0.93617
ISLB 150 @ 139.9 N/m ISLB 175 @ 163.8 N/m ISLB 200 @ 194.2 N/m ISLB 225 @ 230.5 N/m
150 175 200 225
1.2372 1.8386 2.6666 3.1426
ISMB 150 @ 146.2 N/m ISMB 175 @ 189.3 N/m ISMB 200 @ 249.2 N/m ISMB 225 @ 306.1 N/m
150 175 200 225
1.4227 2.2915 3.9432 5.7324
ISWB 150 @ 166.8 N/m ISWB 175 @ 216.8 N/m ISWB 200 @ 282.5 N/m ISWB 225 @ 332.6 N/m
150 175 200 225
2.5558 5.2667 7.8014 8.7434
ISHB 150 @ 339.4 N/m ISHB 200 @ 365.9 N/m ISHB 200 @ 392.4 N/m ISHB 225 @ 422.8 N/m ISHB 225 @ 459.1 N/m
150 200 200 225 225
11.078 8.6252 10.335 8.1401 10.325
IV. CONCLUSION
The buckling load increases with the increase in the height of the section. Consistent increase in the critical load is observer as we increase the grade of the steel. About 100 fold increase in the buckling load is seen as we move from ISJB 150 to ISHB 150. Thus if we want to restrict the dimension of the section for a given load then ISHB is the most favorable option. As ISHB can bear greater load for a given height of the section thus it is more favorable in providing the aesthetical view to a building. Generally the buckling load increases with the increase in the designation of the steel. But there are some anomalies observed in the ISHB section of steel also its failure is quite different from the rest of the section. Most of the section gets failed due to deflection at the free end while in the case o ISHB steel the structure fails due to deflection at the free end , but the section also distorts near the fixed end and also the buckling value gets decreased in this case. The Built up column behavior of the various I section beam still need to be investigated in detail.
[5]
[6]
[7]
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[2]
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[8]
Andrews KRF, England GL, Ghani E. Classification of the axial collapse of cylindrical tubes under quasi-static loading. Int J Mech Sci. 1983; 25:687–96. Reid SR. Plastic deformation mechanisms in axially compressed metal tubes used as impact energy absorbers. Int J Mech Sci 1993; 35:1035–52. Jones N. Structural impact. Cambridge: Cambridge University Press; 1989. Bardi FC, Kyriakides S. Plastic buckling of circular tubes under axial
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compression-Part I: Experiments. Int J Mech Sci. 2006; 48:830–41 G. Lu, T. Yu, Energy Absorption of Structures and Materials, Wood head Publishing Limited, 2003. S.R. Reid, Plastic deformation mechanisms in axial compressed metal tubes used as impact energy absorbers, Int J. Mech. Sci. 35 (1993) 1035–1052. A.A.A. Alghamdi, Collapsible impact energy absorbers: an overview, Thin Walled Struct. 39 (2001) 189–213. IS 808 : 1989 (Reaffirmed1999) Edition4.1 (1992-07) Indian Standard dimensions for hot rolled steel beam, column, channel and angle sections ( Third Revision ) Incorporating Amendment No.1) UDC 669.14-423.2122.4:006.78 ©BIS2002. User’s Guide ANSYS 15.0, Ansys, Inc, Houston,USA. Is 800:2007 General construction in steelCode of practice.(Third revision).