Browse > Article
http://dx.doi.org/10.12989/scs.2022.42.1.001

Behaviour and strength of back-to-back built-up cold-formed steel unequal angle sections with intermediate stiffeners under axial compression  

Gnana Ananthi, G. Beulah (Division of Structural Engineering, College of Engineering Guindy Campus, Anna University)
Roy, Krishanu (Department of Civil & Environmental Engineering, The University of Auckland)
Lim, James B.P. (Department of Civil & Environmental Engineering, The University of Auckland)
Publication Information
Steel and Composite Structures / v.42, no.1, 2022 , pp. 1-22 More about this Journal
Abstract
In cold-formed steel (CFS) structures, such as trusses, transmission towers and portal frames, the use of back-to-back built-up CFS unequal angle sections are becoming increasingly popular. In such an arrangement, intermediate welds or screw fasteners are required at discrete points along the length, preventing the angle sections from buckling independently. Limited research is available in the literature on axial strength of back-to-back built-up CFS unequal angle sections. The issue is addressed herein. This paper presents an experimental investigation reported by the authors on back-to-back built-up CFS unequal angle sections with intermediate stiffeners under axial compression. The load-axial shortening behaviour along with the deformed shapes at failure are reported. A nonlinear finite element (FE) model was then developed, which includes material non-linearity, geometric imperfections and modelling of intermediate fasteners. The FE model was validated against the experimental test results, which showed good agreement, both in terms of failure loads and deformed shapes at failure. The validated finite element model was then used for the purpose of a parametric study comprising 96 models to investigate the effect of longer to shorter leg ratios, stiffener provided in the longer leg, thicknesses and lengths on axial strength of back-to-back built-up CFS unequal angle sections. Four different thicknesses and seven different lengths (stub to slender columns) with three overall widths to the overall depth (B/D) ratios were investigated in the parametric study. Axial strengths obtained from the experimental tests and FE analyses were used to assess the performance of the current design guidelines as per the Direct Strength Method (DSM); obtained comparisons show that the current DSM is conservative by only 7% and 5% on average, while predicting the axial strengths of back-to-back built-up CFS unequal angle sections with and without the stiffener, respectively.
Keywords
axial strength; back-to-back built-up sections; buckling; cold-formed steel; finite element modelling; stiffened unequal angle sections;
Citations & Related Records
Times Cited By KSCI : 10  (Citation Analysis)
연도 인용수 순위
1 Ananthi, G.B.G. and Ashvini, B. (2019a), "Experimental theoretical and numerical studies on cold formed steel stub channel columns with stiffeners", Asian J. Civil Eng., 20, 171-185. https://doi.org/10.1007/s42107-018-0096-2.   DOI
2 Ananthi, G.B.G., Roy, K. and Lim, J.B.P. (2019b), "Experimental and numerical investigations on axial strength of back-to-back built-up cold-formed steel angle columns", Steel Compos. Struct., Int. J., 31(6), 601-615. https://doi.org/10.12989/scs.2019.31.6.601.   DOI
3 Ananthi, G.B.G., Roy, K. and Lim, J.B.P. (2021c), "Tests and finite element modelling of cold-formed steel zed and hat section columns under axial compression", Int. J. Steel Struct., 21(4), 1305-1331. https://doi.org/10.1007/s13296-021-00504-y.   DOI
4 Ananthi, G.B.G., Roy, K., Chen, B. and Lim, J.B.P, (2019c), "Testing, simulation and design of back-to-back built-up cold-formed steel unequal angle sections under axial compression", Steel Compos. Struct., Int. J., 33(4), 595-614. http://dx.doi.org/10.12989/scs.2019.33.4.595.   DOI
5 Aruna, G., Karthika, V. and Sukumar, S. (2020), "Finite element analysis and design of cold-formed steel built-up closed columns with flange and web intermediate stiffeners", Canadian J. Civil Eng., 47(10), 1175-1187. https://doi.org/10.1139/cjce2019-0063.   DOI
6 Roy, K., Mohammadjani, C. and Lim, J.B.P. (2019a), "Experimental and numerical investigation into the behaviour of face-to-face built-up cold-formed steel channel sections under compression", Thin-Walled. Struct., 134, 291-309. https://doi.org/10.1016/j.tws.2018.09.045.   DOI
7 Mathison, C., Roy, K., Clifton, G.C., Ahmadi, A., Masood, R. and Lim, J.B.P. (2019), "Novel pin jointed moment connection for cold-formed steel trusses", Steel Compos. Struct., 31(5), 453-467. http://dx.doi.org/10.12989/scs.2019.31.5.453.   DOI
8 Piyawat, K., Ramseyer, C. and Kang, T.H.K. (2013), "Development of an axial load capacity equation for doubly symmetric built-up cold-formed sections", J. Struct. Eng. Am. Soc. Civil Engr., 139(12), 04013008-04013013. https://doi.org/10.1061/(ASCE)ST.1943-541X.0000780.   DOI
9 Roy, K. and Lim, J.B.P. (2019c), "Numerical investigation into the buckling behavior of face-to-face built-up cold-formed stainless steel channel sections under axial compression", Structures, 20, 42-73. https://doi.org/10.1016/j.istruc.2019.02.019.   DOI
10 Reyes, W. and Guzman, A. (2011), "Evaluation of the slenderness ratio in built-up cold-formed box sections", J. Construct. Steel Res., 67, 929-935. https://doi.org/10.1016/j.jcsr.2011.02.003.   DOI
11 Roy, K., Lau, H.H and Lim, J.B.P. (2019d), "Finite element modelling of back-to-back built-up cold-formed stainless-steel lipped channels under axial compression", Steel Compos. Struct., Int. J., 33(1), 37-66. http://dx.doi.org/10.12989/scs.2019.33.1.037.   DOI
12 Roy, K., Lau, H.H, Ting, T.C.H., Masood, R., Kumar, A. and Lim, J.B.P. (2019f), "Experiments and finite element modelling of screw pattern of self-drilling screw connections for high strength cold-formed steel", Thin-Walled. Struct., 145, 106393. https://doi.org/10.1016/j.tws.2019.106393.   DOI
13 Roy, K., Lau, H.H. Ting, T.C.H., Chen, B. and Lim, J.B.P. (2020), "Flexural capacity of gapped built-up cold-formed steel channel sections including web stiffeners", J. Construct. Steel Res., 172, 106154. https://doi.org/10.1016/j.jcsr.2020.106154.   DOI
14 Yousefi, A.M., Uzzaman, A., Lim, J.B.P., G. Clifton, C. and Young, B. (2017), "Numerical investigation of web crippling strength in cold-formed stainless steel lipped channels with web openings subjected to interior-two-flange loading condition", Steel Compos. Struct., 23(3), 363-383. http://dx.doi.org/10.12989/scs.2017.23.3.363.   DOI
15 American Iron and Steel Institute (2016), North American specification for the design of cold-formed Steel Structural Members, NAS S100.
16 Ting, T.C.H., Roy, K., Lau, H.H. and Lim, J.B.P. (2018), "Effect of screw spacing on behavior of axially loaded back-to-back cold-formed steel built-up channel sections", Adv. Struct. Eng., 21(3), 474-487. https://doi.org/10.1177/1369433217719986.   DOI
17 Ye, J., Hajirasouliha, I. and Becque, J. (2018a), "Experimental investigation of local-flexural interactive buckling of cold-formed steel channel columns", Thin-Walled. Struct., 125, 245-258. https://doi.org/10.1016/j.tws.2018.01.020.   DOI
18 Ananthi, G.B.G., Deepak, M.S., Roy, K. and Lim, J.B.P. (2021b), "Influence of intermediate stiffeners on the axial capacity of cold-formed steel back-to-back built-up unequal angle sections, Structures., 32, 827-848. https://doi.org/10.1016/j.istruc.2021.03.059.   DOI
19 Kyvelou, P., Gardner, L. and Nethercot, D.A. (2017), "Design of composite cold-formed steel flooring systems", Structures, 12, 242-252. https://doi.org/10.1016/j.istruc.2017.09.006.   DOI
20 ABAQUS (2018), Version 6.14-2, SIMULIA, Providence, RI, U.S.A.
21 Qu, S., Zhang, B., Guo, Y., Sun, Q. and Yi, W. (2020), "Ultimate strength of pinned-end dual-angle cross combined section columns under axial compression", Thin-Walled Struct., 157, 107062. https://doi.org/10.1016/j.tws.2020.107062.   DOI
22 Roy, K., Ting, T.C.H., Lau, H.H. and Lim, J.B.P. (2018c), "Nonlinear behavior of axially loaded back-to-back built-up cold-formed steel un-lipped channel sections", Steel Compos. Struct., 28(2), 233-250. https://doi.org/10.12989/scs.2018.28.2.233.   DOI
23 Anbarasu, M. and Adil Dar, M. (2020), "Improved design procedure for battened cold-formed steel built-up columns composed of lipped angles", J. Construct. Steel Res., 164, 105781. https://doi.org/10.1016/j.jcsr.2019.105781.   DOI
24 Young, B. and Chen, J. (2008), "Column tests of cold-formed steel non-symmetric lipped angle sections", J. Construct. Steel Res., 64, 808-815. https://doi.org/10.1016/j.jcsr.2008.01.021.   DOI
25 Roy, K., Lau, H.H. and Lim, J.B.P. (2019e), Numerical investigations on the axial capacity of back-to-back gapped built-up cold-formed stainless steel channels, Adv. Struct. Eng., 22(10), 2289-2310. https://doi.org/10.1177%2F1369433219837390.   DOI
26 Ananthi, G.B.G. (2018), "A study on cold-formed steel compound angle section subjected to axial compression", KSCE J. Civil Eng., 22(5), 1803-1815. https:// DOI 10.1007/s12205-017-1221-6.   DOI
27 Ananthi, G.B.G., Roy, K., Ahmed, A.M.M and J.B.P. Lim. (2021a), "Non-linear behaviour and design of web stiffened battened built-up stainless steel channel sections under axial compression", Struct., 30, 477-494. https://doi.org/10.1016/j.istruc.2021.01.014.   DOI
28 Ananthi, G.B.G., Vishnuvardhan, S and Knight, G.M.S. (2015b), "Experimental and numerical investigation on thin walled single and starred angle sections under compression", Arab. J. Sci. Eng., 40(12), 3417-3427. https://doi.org/10.1007/s13369-015-1776-9.   DOI
29 Aruna, G., Sukumar, S. and Karthika, V. (2015), "Study on coldformed steel built-up square sections with intermediate flange and web stiffeners", Asian J. Civil Eng. (BHRC), 16(07), 919-931.
30 Chen, B., Roy, K., Uzzaman, A., Raftery, G.M. and Lim, J.B.P. (2020a), "Parametric study and simplified design equations for cold-formed steel channels with edge-stiffened holes under axial compression", J. Construct. Steel Res., 172, 106161. https://doi.org/10.1016/j.jcsr.2020.106161.   DOI
31 European Committee for Standardization (CEN) (2009), Metallic Materials - Tensile Testing. 1: Method of Test at Room Temperature, EN ISO 6892-1, Brussels, Belgium.
32 Roy, K., Ting, T.C.H., Lau, H.H. and Lim, J.B.P. (2018d), "Experimental investigation into the behaviour of back-to-back gapped built-up cold-formed steel channel sections under compression", Wei-Wen Yu International Specialty Conference on Cold-Formed Steel Structures-Recent Research and Developments in Cold-Formed Steel Design and Construction, St. Louis, November.
33 Roy, K., Ting, T.C.H., Lau, H.H. and Lim, J.B.P. (2018a), "Effect of thickness on the behaviour of axially loaded back-to-back cold-formed steel built-up channel sections - Experimental and numerical investigation", Structures, 16, 327-346. https://doi.org/10.1016/j.istruc.2018.09.009.   DOI
34 Chen, B., Roy, K., Uzzaman, A., Raftery, G.M. and Lim, J.B.P. (2020b), "Axial strength of back-to-back cold-formed steel channels with edge-stiffened holes, un-stiffened holes and plain webs", J. Construct. Steel Res., 174, 106313. https://doi.org/10.1016/j.jcsr.2020.106313.   DOI
35 ASCE (2005), Minimum Design Loads for Buildings and other Structures, American Society of Civil Engineers Standard, New York, 2005.
36 Roy, K., Ting, T.C.H., Lau, H.H. and Lim, J.B.P. (2018b), "Nonlinear behaviour of back-to-back gapped built-up cold-formed steel channel sections under compression", J. Construct. Steel Res., 147, 257-276. https://doi.org/10.1016/j.jcsr.2018.04.007.   DOI
37 Roy, K., Ting, T.C.H., Lau, H.H. and Lim, J.B.P. (2019b), "Experimental and numerical investigations on the axial capacity of cold-formed steel built-up box sections", J. Construct. Steel Res., 160, 411-427. https://doi.org/10.1016/j.jcsr.2019.05.038.   DOI
38 Schafer, B.W. and Pekoz, T. (1998), "Computational modelling of cold-formed steel: characterizing Geometric imperfections and residual stress", J. Constr. Steel Res., 47, 193-210. https://doi.org/10.1016/S0143-974X (98)00007-8.   DOI
39 Shi, G., Liu, Z., Ban, H.Y., Zhang, Y., Shi, Y.J. and Wang, Y.Q. (2011), "Tests and finite element analysis on the local buckling of 420 MPa steel equal angle columns under axial compression", Steel Compos. Struct., 12(1), 31-51. https://doi.org/10.12989/scs.2011.12.1.031.   DOI
40 Ellobody, E. and Young, B. (2007), "Design of cold-formed steel unequal angle compression members", J. Construct. Steel Res., 45, 330-338. https://doi.org/10.1016/j.tws.2007.02.015.   DOI
41 Dabaon, M., Ellobody, E. and Ramzy, K. (2015), "Nonlinear behavior of built-up cold-formed steel section battened columns", J. Construct. Steel Res., 110, 16-28. http://dx.doi.org/10.1016/j.engstruct.2005.07.005.   DOI
42 Standards Australia (2018), Cold-Formed Steel Structures, AS/NZS 4600:2018, Standards Australia/ Standards New Zealand.
43 Ananthi, G.B.G., Palani, G.S and Iyer, N.R. (2016), "A study on cold-formed steel web stiffened lipped battened channel columns", J. Struct. Eng. (JoSE), 4(43), 133-141.
44 Dar, M.A., Subramanian, Rather, A.I., N., Dar, A.R., Lim, J.B.P., Anbarasu, M. and Roy, K. (2019), "Effect of angle stiffeners on the flexural strength and stiffness of cold-formed steel beams", Steel Compos. Struct., 33(2), 225-243. https://doi.org/10.12989/scs.2019.33.2.225.   DOI
45 Deepak, M.S. and Ananthi, G.B.G. (2021), "Local buckling behaviour and capacities of Cold-Formed Steel Double-I-Box stub and short column sections", Structures, 34, 1761-1784. https://doi.org/10.1016/j.istruc.2021.08.124.   DOI
46 EC3. Eurocode 3 (2005), Design of Steel Structures. Part 1-1: General Rules and Rules for Building. British Standard Institution, BS EN 1993-1-1, London, U.K.
47 EI, Aghoury, M.A., El, Salem, A.H., Hanna, M.T. and Amoush E.A. (2013), "Ultimate capacity of battened columns composed of four equal slender angles", Thin-Walled Struct., 63, 175-185. https://doi.org/10.1016/j.tws.2012.07.019.   DOI
48 Stone, T.A. and LaBoube, R.A. (2005), "Behaviour of cold-formed steel built-up I-sections", Thin-Walled. Struct., 43(12), 1805-1817. https://doi.org/10.1016/j.tws.2005.09.001.   DOI
49 Uzzaman, A., Lim, J. B.P., Nash, D. and Roy, K. (2020a), "Cold-formed steel channel sections under end-two-flange loading condition: Design for edge-stiffened holes, unstiffened holes and plain webs", Thin-Walled. Struct., 147, 106532, 38-48. https://doi.org/10.1016/j.tws.2019.106532.   DOI
50 Lim, J.B.P. and Nethercot, D.A. (2003), "Serviceability design of a cold-formed steel portal frame having semi-rigid joints", Steel Compos. Struct., 3(6), 451-474. https://DOI:10.12989/scs.2003.3.6.451.   DOI
51 Uzzaman, A., Lim, J.B.P., Nash, D. and Roy, K. (2020b), "Web crippling behaviour of cold-formed steel channel sections with edge-stiffened and unstiffened circular holes under interior-two-flange loading condition", Thin-Walled. Struct., 154, 106813. https://doi.org/10.1016/j.tws.2020.106813.   DOI
52 Uzzaman, A., Lim, J.B.P., Nash, D. and Young, B. (2017), "Effects of edge-stiffened circular holes on the web crippling strength of cold-formed steel channel sections under one-flange loading conditions", Eng. Struct., 139, 96-107. http://dx.doi.org/10.1016/j.engstruct.2017.02.042.   DOI
53 Whittle, J. and Ramseyer, C. (2009), "Buckling capacities of axially loaded, cold-formed, built-up channels", Thin-Walled. Struct., 47(2), 190-201. https://doi.org/10.1016/j.tws.2008.05.014.   DOI
54 Ye, J., Mojtabaei, S.M. and Hajirasouliha, I. (2018b), "Local-flexural interactive buckling of standard and optimised cold-formed steel columns", J. Construct. Steel Res., 144, 106-118. https://doi.org/10.1016/j.jcsr.2018.01.012.   DOI
55 Zhang, J.H. and Young, B. (2012), "Compression tests of cold-formed steel I-shaped open sections with edge and web stiffeners", Thin-Walled Struct. 52, 1-11. https://doi.org/10.1016/j.tws.2011.11.006.   DOI
56 Chi, Y., Roy, K., Chen, B., Fang, Z., Uzzaman, A., Ananthi, G.B.G. and Lim, J.B.P. (2021), "Effect of web hole spacing on axial capacity of back-to-back cold-formed steel channels with edge-stiffened holes", Steel Compos. Struct., 40(2), 287-305. http://dx.doi.org/10.12989/scs.2021.40.2.287.   DOI
57 Vishnuvardhan, S. (2006), Behaviour of Cold-Formed Steel Single and Ccompound Angles in Compression, Ph.D. Dissertation, Anna University, Chennai, India.
58 Chen, B., Roy, K., Uzzaman, A., Raftery, G.M., Nash, D., Clifton, G.C., Pouladi, P. and Lim, J.B.P. (2019), "Effects of edge-stiffened web openings on the behaviour of cold-formed steel channel sections under compression", Thin-Walled Struct., 144, 106307. https://doi.org/10.1016/j.tws.2019.106307.   DOI
59 Chen, B., Roy, K., Uzzaman, A. and Lim, J.B.P. (2020c), "Moment capacity of cold-formed channel beams with edge-stiffened web holes, un-stiffened web holes and plain webs", Thin-Walled Struct., 157, 107070. https://doi.org/10.1016/j.tws.2020.107070.   DOI
60 Ananthi, G.B.G., Vishnuvardhan, S and Knight, G.M.S. (2015a), "Experimental, theoretical and numerical study on thin walled steel single and compound channel sections in axial compression", Indian J. Eng. Mater. Sci., 22(5), 570-580. http://hdl.handle.net/123456789/33440.
61 CUFSM Software (2018), Constrained and Unconstrained Finite Strip Method, John Hopkins University, U.S.A.
62 Dar, M.A., Sahoo, D.R., Pulikkal, S. and Jain, A.K. (2018), "Behaviour of laced built-up cold-formed steel columns: Experimental investigation and numerical validation", Thin-Wall. Struct., 132, 398-409. http://dx.doi.org/10.12989/scs.2018.27.5.545.   DOI