This paper investigates the effects of stiffeners on the compressive and flexural capacities of coldformed steel channel members. Stiffeners are added on the web of the channel section to form a new section called SupaCee. This new section is shown to be more innovative and stable than the traditional channel section. The structural advantages of this new section are investigated by comparing the capacities of SupaCee and channel members under compression and bending. The capacities are determined by using the direct strength method (DSM) according to ASNZS 4600:2018 with the support of THINWALL2, a buckling analysis program. It was found that the stiffeners are effective for small section dimensions and thicknesses, but become ineffective for large section dimensions.
4 Steel Construction Volume 14 November 2021 ISSN 1867-0520 Design and Research – Plastic design of high-strength steel beams – Optimized RHS fillet welds for EN 19931-8 – Corrosion protection for cold-formed structural steel elements – Buckling of aluminium members with longitudinal welds – part – Effects of stiffeners on cold-formed channels – Behaviour and design of stainless steel EHS Content Steel Construction 4/21 Steel and composite bridges offer economic advantages, even for short and medium spans To simplify and speed up the design process, ArcelorMittal now offers Advance Bridge Expert, a free preliminary design software that includes complex geometries and innovative solutions The software is suitable for the pre-dimensioning of curved and/or skewed composite road, railway and pedestrian bridges according to the Eurocodes and several National Annexes It supports the predesign of steel composite bridges, filler beam bridges and PreCoBeam/composite dowel strips using the hot-rolled section and modern steel grades libraries of ArcelorMittal up to S460, including HISTAR® grades and weathering steel (Arcorox®) according to EN 10025-5:2019 The free version of Advance Bridge Expert can be downloaded from the following website: https://sections.arcelormittal.com/design_aid/ design_software/EN (© ArcelorMittal) s article pp A4 (Photo: Wirkowice composite bridge in Poland: Europe’s first road bridge in Arcorox 460đ weathering steel â MOSTY ZAMOSC Tomasz CzyzÃ) EDITORIAL 221 Bernhard Hauke European Steel Design Awards 2021 DESIGN & RESEARCH Helen Bartsch, Felix Eyben, Simon Schaffrath, Markus Feldmann 222 On the plastic design of high-strength steel beams Benjamin Newcomb, Kyle Tousignant 236 Optimized design of fillet welds in RHS joints for EN 1993-1-8 Alexander Britner, Corinne Dieu, Ralf Podleschny 250 Corrosion protection for cold-formed structural steel elements Thomas Misiek, Bert Norlin, Reinhold Gitter, Torsten Höglund 258 Review of European design provisions for buckling of aluminium members with longitudinal welds – part Ngoc Hieu Pham, Quoc Anh Vu 270 Effects of stiffeners on the capacities of cold-formed steel channel members Asif Mohammed, Katherine Cashell 279 Cross-sectional behaviour and design of ferritic and duplex stainless steel EHS in compression STEEL CONSTRUCTION NEWS 288 288 ECCS news 293 Events Volume 14 November 2021, No. 4 ISSN 1867-0520 (print) ISSN 1867-0539 (online) http://wileyonlinelibrary.com/journal/stco Steel Construction is indexed in Elsevier´s Scopus CiteScore 2020: 1.9 Journal for ECCS members www.ernst-und-sohn.de/steel-construction A4 PRODUCTS & PROJECTS DOI: 10.1002/stco.202100003 ARTICLE Ngoc Hieu Pham, Quoc Anh Vu Effects of stiffeners on the capacities of cold-formed steel channel members This paper investigates the effects of stiffeners on the compressive and flexural capacities of cold-formed steel channel members Stiffeners are added on the web of the channel section to form a new section called SupaCee This new section is shown to be more innovative and stable than the traditional channel section The structural advantages of this new section are investigated by comparing the capacities of SupaCee and channel members under compression and bending The capacities are determined by using the direct strength method (DSM) according to AS/NZS 4600:2018 with the support of THINWALL-2, a buckling analysis program It was found that the stiffeners are effective for small section dimensions and thicknesses, but become ineffective for large section dimensions Keywords cold-formed steel; channel members; stiffeners; compressive capacities; flexural capacities 1 Introduction Cold-formed steel lipped channel and zed sections have been available on the international markets for more than 30 years [1] The yield stresses of material properties ranging from 450 to 550 MPa [2] depend on the thickness and the cold-forming procedure The channel and zed sections in recent developments have stiffeners added on their flanges, webs and lips to increase the buckling capacities, and such sections are known as SupaCee and SupaZed The new sections have the following benefits [3]: 1) The rounded lips of the sections (instead of sharp edges) make handling safer on site 2) Better safety and reduced labour input can be achieved while installing purlins 3) The strength performance is significantly improved, resulting in considerable economic benefits In terms of design methods, the effective width method (EWM) was proposed by von Karman based on the flat plate stability [4], then calibrated by Winter for coldformed steel members [5], [6] The interaction between local and global buckling modes is accounted for in the design, but this method becomes too complicated when designing complex section shapes with multiple stiffeners The limitation of the EWM can be solved by using the direct strength method (DSM) The DSM was derived from the design method for distortional buckling failures proposed by Hancock et al [7] and then developed by Scha fer and Pekoz [8]–[10] This method is currently formulat270 ed in the Australian/New Zealand Standard AS/NZS 4600:2018 [11] and the North American Specification AISI S100-16 [12] for the design of cold-formed steel structures Compared with the EWM [8], the DSM has the following advantages: – Design procedures are simple for complex sections with multiple stiffeners – Elastic buckling analysis using numerical tools is utilized to consider the equilibrium between plate elements not accounted for in the EWM The development of the DSM provides deeper insights into the buckling behaviour of complex shapes [1] Elastic buckling analyses are compulsory, and can be carried out by numerical software programs such as THIN-WALL-2 ([13], [14]) or CUFSM [15] The signature curve is one of the elastic buckling analysis results This curve shows the buckling stress versus buckling half-wavelength and can be used to optimize the section shapes The DSM was used in this research The addition of stiffeners to cold-formed steel sections has been investigated by many researchers In terms of compression members, Hancock et al ([7], [16]–[19]) performed a series of experiments on cold-formed steel storage racks with a variety of complex edge stiffeners The behaviour of members with edge stiffeners provided deeper insights into distortional buckling Seah and Rhodes [20] also conducted tests on isolated flanges with complex stiffeners to investigate their behaviour, which was followed by the modification of the British Standard using the effective width method with consideration of the distortional mode in design Wang et al., Yan and Young, and Xiang et al ([21]–[27]) investigated the behaviour of cold-formed steel channel columns with complex edge stiffeners Manikandan et al [28] studied the behaviour of three types of intermediate web stiffener on lipped channel sections under compression In addition, Chen et al [29] presented a variety of stub column tests on coldformed steel channel and zed sections with different stiffeners The experimental results in Chen’s paper [29] were used to calibrate the finite element models that can be utilized to develop numerical studies to expand the database for a variety of sections and lengths The experimental and numerical results were compared with the predictions from the current standards and the modifications in design were then proposed The optimization of coldformed steel channel columns was carried out by El-taly et al [30] with combinations of edge and intermediate © 2021 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co KG, Berlin Steel Construction 14 (2021), No stiffeners The stiffeners to web openings were also investigated to find out their effects on the behaviour of coldformed steel channel sections under compression ([31], [32]) In terms of flexural members, Ye et al [33] investigated the more efficient cold-formed steel channel sections in bending based on Eurocode [34] It was found that the intermediate web stiffeners did not increase the flexural capacity of the channel sections, while complex edge stiffeners resulted in a considerable increase in the flexural capacity of the sections Manikandan and Arun [35] examined the bending behaviour of cold-formed built-up I‑sections (back-to-back channel beam) with edge and intermediate web stiffeners The test and numerical results were compared with the predictions from standards and were used for design modifications Chun-gang et al [36] also studied the effects of web stiffeners on the flexural capacities of channel sections Their paper illustrated that the intermediate web stiffeners did not increase the bending strengths of channel sections, as presented in the work of Ye et al [33] The reason for this ineffectiveness is that the flexural strengths of the sections investigated were governed by distortional buckling, whereas the intermediate stiffeners were only useful for the local buckling strength Chen also studied the behaviour of coldformed steel channel beams with edge-stiffened web holes [37] Openings to accommodate technical services are common in cold-formed steel members Previous research has focused on experimental and numerical studies of cold-formed steel sections with the addition of stiffeners that were used for optimizing sections or design modifications However, the effectiveness of additional stiffeners for member capacities remains a question, particularly for commercial sections available on the market This effectiveness is taken into account by designers and can be evaluated based on the same amount of material for the sections with and without stiffeners This paper attempts to answer this question by investigating the effects of complex stiffeners on the capacities of channel members under compression or bending Channel and SupaCee sections were commercial sections provided by BlueScope Lysaght [3], and their material properties are regulated in AS 1397 [2] The capacities of cold-formed steel members can be determined using the DSM design equations formulated in AS/NZS 4600:2018 [11] with the support of THIN-WALL-2 ([13], [14]) in sectional elastic buckling analyses The effectiveness of stiffeners is then evaluated by comparing the capacities of SupaCee and channel members under compression or bending Material properties and cross-section dimensions 2.1 Material properties The material properties of cold-formed steel members are regulated in Australian Steel Standard AS 1397 [2] or by Fig. 1 Stress-strain curve of G450 steel [1] the American Society for Testing Materials (ASTM) In this paper, material grades according to AS 1397[2] describe a range of coated steels from G250 to G550 A designation in the form G450-Z200 signifies a typical grade, where the letter G indicates heat treatment prior to hot-dipping, the first three-digit number (450) denotes the minimum yield stress in MPa, the letter Z indicates a zinc coating and the second three-digit number (200) denotes the coating mass in grams per square metre on both sides of the steel sheet Six coating types are regulated: Z stands for zinc coating, ZF for zinc-iron alloy, ZA for zinc/aluminium coating, ZM for zinc/aluminium/magnesium coating and AM for aluminium/zinc/magnesium, where aluminium prevails The stress-strain curve of G450 steel to AS 1397 [2] is illustrated in Fig. 1, where the yield stress fy is based on a 0.2 % proof stress This rounded curve and the low ratio of tensile strength to yield stress are due to the cold reduction processes Grade G450 was used for the investigations in this paper 2.2 Cross-section dimensions The channel and SupaCee sections were commercial sections provided by BlueScope Lysaght [3], and their dimensions are listed in Tab. 1 The section properties and elastic buckling stresses were determined using THINWALL-2 ([13], [14]) The member lengths for each section varied from 2.0 to 8.0 m for compression or bending In order to evaluate the effectiveness of stiffeners, structural members using channel and SupaCee sections require the same amount of material The collected data is then used to compare the capacities of SupaCee and channel section members under compression or bending This comparison is presented in sections and Direct strength method for cold-formed steel structures The direct strength method (DSM) is used to predict the ultimate strengths of cold-formed steel members based on Steel Construction 14 (2021), No 4271 ARTICLE N H Pham, Q A Vu: Effects of stiffeners on the capacities of cold-formed steel channel members N H Pham, Q A Vu: Effects of stiffeners on the capacities of cold-formed steel channel members Tab. 1 Nominal dimensions of channel and SupaCee sections Section t D B L1 L2 L GS S α1 α2 SC/C15012 1.2 152 64 7.5 7.5 14.5 64 42 35 SC/C15015 1.5 152 64 7.5 7.5 14.5 64 42 35 SC/C15019 1.9 152 64 7.5 7.5 14.5 64 42 35 SC/C15024 2.4 152 64 7.5 7.5 14.5 64 42 35 SC/C20012 1.2 203 76 10 10 19.5 115 42 35 SC/C20015 1.5 203 76 10 10 19.5 115 42 35 SC/C20019 1.9 203 76 10 10 19.5 115 42 35 SC/C20024 2.4 203 76 10 10 19.5 115 42 35 SC/C25015 1.5 254 76 11 11 21.5 166 42 35 SC/C25019 1.9 254 76 11 11 21.5 166 42 35 SC/C25024 2.4 254 76 11 11 21.5 166 42 35 SC/C30019 1.9 300 96 14 14 27.5 212 42 35 SC/C30024 2.4 300 96 14 14 27.5 212 42 35 SC/C30030 3.0 300 96 14 14 27.5 212 42 35 SC/C35019 1.9 350 125 15 15 30.0 262 42 35 SC/C35024 2.4 350 125 15 15 30.0 262 42 35 SC/C35030 3.0 125 125 15 15 30.0 262 42 35 SC/C40019 1.9 400 125 15 15 30.0 312 42 35 SC/C40024 2.4 400 125 15 15 30.0 312 42 35 SC/C40030 3.0 400 125 15 15 30.0 312 42 35 Note: inner radius r1 = r2 = 5 mm; t, D, B, L1, L2, GS, S (mm); α1, α2 (0) buckling (Nce), local buckling (Ncl) and distortional buckling (Ncd) λ2 0.658 c N y for λc ≤ 1.5 Nce = (1) 0.877 N for λ > 1.5 c λc y Fig. 2 Nomenclature for channel and SupaCee sections the elastic buckling stresses (fo, fol, fod) and the yield stress (fy) The non-dimensional slenderness values are calculated and used directly to determine the global, local and distortional buckling strengths as shown in Eqs (1)–(3) and (4)–(6) for compression and bending respectively The nominal capacity of compression members is calculated as the minimum of the nominal strengths for global 272 Steel Construction 14 (2021), No Ncl = Ncd = Nce for λl ≤ 0.776 0.4 0.4 1 − 0.15 Nol Nol N for λ > 0.776 ce l Nce Nce (2) N y for λd ≤ 0.561 0.6 0.6 N N od od 1 − 0.25 N N N y for λd > 0.561 y y (3) where: λc = N y /Noc ; λl = Nce /Nol ; λd = N y /Nod Ny Noc Nol Nod nominal yield capacity of member in compression elastic compression buckling load elastic local buckling load elastic distortional buckling load The nominal moment capacity (Mb) is the minimum of the nominal strengths for lateral-torsional buckling (Mbe), local buckling (Mbl) and distortional buckling (Mbd) Mo for Mo < 0.56 My 10 10 My 1 − My for 0.56 My ≤ Mo ≤ 2.78 My Mbe = 36 Mo My for Mo > 2.78 My (4) Mbl = Mbd = Mbe for λl ≤ 0.776 0.4 0.4 1 − 0.15 Mol Mol M for λ > 0.776 be l Mbe Mbe (5) My for λd ≤ 0.673 0.5 0.5 M M od od 1 − 0.22 M M My for λd > 0.673 y y (6) where: λl = Mbe /Mol ; λd = My /Mod My Mo Mol Mod yield moment elastic lateral-torsional buckling moment elastic local buckling moment elastic distortional buckling moment Note that local buckling strengths (Ncl, Mcl) consider the interactions between local and global buckling modes The pure local buckling strengths were only determined for a fully braced column and beam by replacing Nce and Mbe by Ny and My in Eqs (2) and (5) respectively For singly symmetric sections subjected to torsional or flexural-torsional buckling, the global buckling stresses under compression and bending are presented in Appendix D of AS/NZS 4600:2018 [11] Sectional buckling stresses, including local and distortional buckling stresses, can be determined using the elastic buckling formulae presented in Appendix D [11] or by using numerical tools such as ABAQUS [38], CUFSM [15], or THIN-WALL-2 ([13], [14]) Tab. 2 Sectional buckling stresses under compression Section fol (MPa) Section Channel SupaCee ∆ (%) 15012 68.57 125.17 82.54 % 15015 104.25 168.23 15019 167.31 15024 fod (MPa) Channel SupaCee ∆ (%) 15012 141.36 134.68 –4.73 % 61.37 % 15015 179.64 172.67 –3.88 % 235.09 40.51 % 15019 239.88 231.68 –3.42 % 266.47 332.76 24.88 % 15024 317.74 308.91 –2.78 % 20012 37.25 62.31 67.28 % 20012 104.3 100.9 –3.26 % 20015 58.23 86.19 48.02 % 20015 133.94 130.53 –2.55 % 20019 93.59 123 31.42 % 20019 176.06 172.95 –1.77 % 20024 149.53 179.62 20.12 % 20024 231.71 231.29 –0.18 % 25015 37.7 50.57 34.14 % 25015 88.65 85.33 –3.75 % 25019 60.53 74.02 22.29 % 25019 118.19 116.12 –1.75 % 25024 96.54 110.68 14.65 % 25024 160.18 159.82 –0.22 % 30019 42.82 50.12 17.05 % 30019 105.26 102.22 –2.89 % 30024 68.42 75.77 10.74 % 30024 138.76 136.3 –1.77 % 30030 107.17 114.49 6.83 % 30030 185.47 186.13 0.36 % 35019 30.68 34.7 13.10 % 35019 86.81 82.67 –4.77 % 35024 49.55 53.33 7.63 % 35024 112.75 109.71 –2.70 % 35030 77.57 81.35 4.87 % 35030 145.81 142.46 –2.30 % 40019 23.96 26.1 8.93 % 40019 63.69 60.83 –4.49 % 40024 38.24 40.51 5.94 % 40024 84.45 82.11 –2.77 % 40030 59.77 62.13 3.95 % 40030 112.8 111.63 –1.04 % Note: ∆% is the buckling stress deviation between SupaCee and channel sections (in %) Steel Construction 14 (2021), No 4273 ARTICLE N H Pham, Q A Vu: Effects of stiffeners on the capacities of cold-formed steel channel members N H Pham, Q A Vu: Effects of stiffeners on the capacities of cold-formed steel channel members Sectional buckling analyses Sectional buckling stresses, including local and distortional buckling stresses, under compression and bending were determined using THIN-WALL-2 ([13], [14]), as presented in Tabs and The local buckling stresses fol of SupaCee sections increased significantly compared with those of channel sections for compression or bending due to the effect of web stiffeners, especially for small and thin cross-sections (see section SC15012) In terms of compression, the distortional buckling stresses of SupaCee sections are slightly lower (< 5 %) than those of channel sections This reduction is insignificant, and the distortional buckling stresses fod are still much higher than the local buckling stresses fol This reduction has no impact on the member capacities because member strengths are governed by local buckling strengths, as presented in section In terms of bending, the distortional buckling stresses fod of SupaCee sections are generally higher than those of Fig. 3 Model configuration for compression members Tab. 3 Sectional buckling stresses under bending Section fol (MPa) Section Channel SupaCee ∆ (%) 15012 323.82 515.68 59.25 % 15015 486.77 700.24 15019 782.32 15024 fod (MPa) Channel SupaCee ∆ (%) 15012 266.93 286.5 7.33 % 43.85 % 15015 333.62 353.76 6.04 % 1018.9 30.24 % 15019 447.14 461.25 3.16 % 1199.89 1416.16 18.02 % 15024 582.9 605.02 3.79 % 20012 190.43 315.35 65.60 % 20012 224.34 238.94 6.51 % 20015 294.28 432.78 47.06 % 20015 285.28 307.95 7.95 % 20019 464.42 616.87 32.83 % 20019 368.48 404.73 9.84 % 20024 754.61 871.54 15.50 % 20024 498.45 528.98 6.12 % 25015 195.83 278.64 42.29 % 25015 254.94 279.15 9.50 % 25019 315.86 411.48 30.27 % 25019 335.19 371.43 10.81 % 25024 511.97 579.62 13.21 % 25024 448.01 471.02 5.14 % 30019 225.21 266.14 18.17 % 30019 278.12 285.08 2.50 % 30024 368.86 408.86 10.84 % 30024 371.27 385.13 3.73 % 30030 555.52 585.86 5.46 % 30030 463.53 485.92 4.83 % 35019 167.52 191.35 14.23 % 35019 205.96 202.57 –1.65 % 35024 251.77 273.52 8.64 % 35024 250.29 251.54 0.50 % 35030 406.71 424.77 4.44 % 35030 333.42 335.83 0.72 % 40019 120.25 134.79 12.09 % 40019 167.24 165.08 –1.29 % 40024 200.88 214.66 6.86 % 40024 226.75 226.7 –0.02 % 40030 311.56 323.01 3.68 % 40030 291.99 292.62 0.22 % Note: ∆% is the buckling stress deviation between SupaCee and channel sections (in %) 274 Steel Construction 14 (2021), No channel sections, with a maximum deviation of 10.81 % for the C25019 section This deviation undergoes reduction trends if the sections vary from C250 to C150 or C250 to C400 These stresses in SupaCee sections are even smaller than those of channel sections, especially for the C/SC350 and C/SC400 sections Effects of stiffeners on the compressive and flexural capacities of cold-formed steel channel members The DSM was used to determine the compressive and flexural capacities of channel and SupaCee section members with a variety of member lengths The model configurations are shown in Figs. 3 and for compression and bending respectively, where L is the member length or span Bracing was placed at the mid-length of the col- Fig. 5 Fig. 4 Model configuration for flexural members umn/beam to reduce the effective length in the weak-axis direction The results are plotted in percentage diagrams, where the horizontal axis is for channel member capacities and the vertical axis is for capacity deviations in percent (%) between SupaCee and channel members, as shown in Figs. 5 and Compressive capacities of cold-formed steel channel columns Steel Construction 14 (2021), No 4275 ARTICLE N H Pham, Q A Vu: Effects of stiffeners on the capacities of cold-formed steel channel members N H Pham, Q A Vu: Effects of stiffeners on the capacities of cold-formed steel channel members Fig. 6 Flexural capacities of cold-formed steel channel beams As shown in Figs. 5a and 6a, the global buckling strengths of SupaCee members are much lower than those of channel members, reaching 15 % lower for compression or bending This is explained by the fact that the section properties Ix, Iy, Iw and J of SupaCee sections are smaller than those of channel sections This deviation increases for long members The distortional buckling strengths (Ncd) of SupaCee members are slightly lower than those of channel members under compression (see Fig. 5c) because the fod values of SupaCee sections are smaller than those of channel sections, as presented in section In terms of bending, distortional buckling moments (Mbd) of the two types of section members are approximative as the deviation fluctuates between –1.72 % and 2.14 %, as presented in Fig. 6c 276 Steel Construction 14 (2021), No Fig. 5b shows that most of the local buckling strengths of SupaCee members are higher than those of channel members under compression Several local buckling strength values of SupaCee members are still lower than those of channel members although the local buckling stresses of the former are higher than those of the latter The reason is that the global buckling strengths (Nce) of the SupaCee members are significantly smaller than those of channel members, resulting in the considerable reduction in Ncl for those SupaCee members, as shown by Eq (2) Similarly to compressive members, almost all local buckling moments of SupaCee members are higher than those of channel members, with a maximum deviation of 17 %, as shown in Fig. 6b Local buckling moments of SupaCee members are smaller than those of channel members for several sections although the local buckling stresses of the former are higher than those of the latter for the following reason: The global bucking moments of long-span SupaCee beams are much smaller than those of channel beams, which results in the significant reduction in local buckling strengths of SupaCee beams, as shown by Eq (5) In general, the compressive and flexural capacities (Nc and Mb) of SupaCee members are higher than those of channel members, with a maximum deviation of 20 % and 9 % for compression and bending respectively (see Figs. 5d and 6d) However, the capacities of several SupaCee members are still smaller than those of channel members for the following reasons: 1) Member capacities are governed by global buckling for thick sections and long members 2) The reduction of the global buckling strengths results in the significant decrease of local buckling strengths of SupaCee members, as discussed 3) Member capacities are governed by the distortional buckling strengths for thin and short members 6 Conclusions This paper investigates the effects of stiffeners on the capacities of channel members under compression or bending Commercial channel and SupaCee sections were provided by BlueScope Lysaght [3] The investigation was carried out by comparing the capacities of channel and SupaCee members The capacities were determined using the direct strength method (DSM) formulated in AS/NZS 4600: 2018 [11] with the support of THIN-WALL-2 software ([13], [14]) in elastic buckling analyses Based on the results, the following conclusions can be drawn: – The stiffeners have significantly beneficial effects on thin and small section members, and marginal effects on thicker and larger sections – The global buckling capacities of SupaCee members are lower than those of channel members, particularly those of slender members Based on these remarks, the following recommendation can be given for engineers and designers: Stiffeners should be used for sections with depths ≤ 300 mm, but are ineffective for large sections with depths > 300 mm References [1] Hancock, G J.; Pham, C H (2016) New section shapes using high-strength steels in cold-formed steel structures in Australia Elsevier Ltd [2] AS1397:2011 (2011) Continuous Hot-dip Metallic Coated Steel Sheet and Strip – Coating of Zinc and Zinc Alloyed with Aluminium and Magnesium Standards Australia [3] BlueScope Lysaght (2014) Supapurlins Supazeds & Supacees Blue Scope Lysaghts [4] Saint-Venant M (1883) Discussion in Theorie De L’elasticite Des Corp Solids [5] Winter, G (1940) Strength Distribution in and Equivalent Width of Flanges of Wide, Thin-Walled Steel Beams NACA: in Technical Note 784 [6] Winter, G (1947) Strength of Thin Steel Compression Flanges in: Transactions 112, pp 527–554 [7] Hancock, G J.; Kwon Y B.; Stefan, B E (1994) Strength design curves for thin-walled sections undergoing 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Structures 157, Sept issue, 107070 [38] Dassault Systemes Simulia Corp (2014) ABAQUS/CAE User’s Manual Providence, RI, USA Authors Dr Ngoc Hieu Pham hieupn@hau.edu.vn Faculty of Civil Engineering Hanoi Architectural University Km 10, Nguyen Trai Street Thanh Xuan District, Hanoi, Vietnam How to Cite this Paper Assoc Prof Quoc Anh Vu (corresponding author) anhvq@hau.edu.vn Faculty of Civil Engineering Hanoi Architectural University Km 10, Nguyen Trai Street Thanh Xuan District, Hanoi, Vietnam 278 Steel Construction 14 (2021), No Pham, N H.; Vu, Q A (2021) Effects of stiffeners on the capacities of cold-formed steel channel members Steel Construction 14, No 4, pp. 270–278 https://doi.org/10.1002/stco.202100003 This paper has been peer reviewed Submitted: 30 January 2021; accepted: 30 May 2021 ... Vu Effects of stiffeners on the capacities of cold- formed steel channel members This paper investigates the effects of stiffeners on the compressive and flexural capacities of cold- formed steel. .. predict the ultimate strengths of cold- formed steel members based on Steel Construction 14 (2021), No 4271 ARTICLE N H Pham, Q A Vu: Effects of stiffeners on the capacities of cold- formed steel channel. .. capacities of cold- formed steel channel columns Steel Construction 14 (2021), No 4275 ARTICLE N H Pham, Q A Vu: Effects of stiffeners on the capacities of cold- formed steel channel members N