The structural efficiency of tapered steel section with perforation under lateral torsional buckling behaviour

Purpose Tapered section can resist maximum stress at a single location while the stresses are considerably lower at the rest of the member; therefore, it could have higher structural efficiency compared to conventional section. It could also satisfy functional requirements while reducing weight and cost in many fields of civil construction. Perforation in the steel section also eases the integration of Mechanical and Electrical (M&E) services such as ventilation pipes and electrical cables within the structural depths of the beam. In this analysis, the structural efficiency of tapered steel section with perforation under lateral-torsional buckling behaviour is investigated. Design/methodology/approach A total of 81 models are analysed using LUSAS software and five variables are investigated which involved perforation sizes, perforation shapes, perforation layout, tapering ratio and flange and Web thickness. Buckling moment is obtained from the analysis results in LUSAS software, while self-weight and structural efficiency are manually calculated. Findings Perforation size of 0.75 D has the highest structural efficiency, although it can withstand a smaller buckling load. This is due to its lower self-weight compared to other perforation sizes. The square perforation shape also has the highest structural efficiency compared to circular perforation and diamond perforation. An increment of percentage in structural efficiency of the square perforation shape with 0.75 D is the highest at 3.07%. The circular perforation shape with 0.75 D (Open-Open-Open perforation layout) has the highest increment of percentage in structural efficiency which is 2.37%. The tapering ratio of 0.3 is the most efficient and an increment of percentage in structural efficiency is 114.36%. The flange thickness of 0.02 m and Web thickness of 0.015 m has the highest structural efficiency at 45.756 and 29.171, respectively. Originality/value In conclusion, a section should be able to resist the large buckling moment and has a lower self-weight to achieve high structural efficiency.

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Experimental Study on Lateral -Torsional Buckling of Triangular Web Profile Steel Section

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.802.178 ◽

2015 ◽

Vol 802 ◽

pp. 178-183 ◽

Cited By ~ 2

Author(s):

Hazwani Hasan ◽

Fatimah De’nan ◽

Kok Keong Choong

Keyword(s):

Bending Test ◽

Lateral Torsional Buckling ◽

Torsional Buckling ◽

Four Point Bending ◽

Percentage Difference ◽

Design Values ◽

Triangular Profile ◽

Steel Sections ◽

Manual Calculation ◽

Steel Section

Triangular web profile (TriWP) is a structural steel section made of two flanges connected to a web plate of triangular profile. The ability of TriWP to resist lateral–torsional buckling (LTB) is one of the most important criteria considered in the design of this steel section. This study examined the LTB behavior of TriWP steel section and determined the buckling moment resistance (Mb,Rd) for TriWP. Beam specimens were analyzed using a four-point bending test. Four types of specimen sizes were used: 200 mm × 100 mm × 6.3 mm × 6 mm; 200 mm × 100 mm × 9 mm × 6.3 mm; 200 mm × 100 mm × 8 mm × 6 mm; and 200 mm × 100 mm × 6 mm × 5 mm sections. Testing results for all specimen sizes showed that the values for Mb,Rdof the TriWP steel sections were higher than those of the flat web section. The percentage difference of Mb,Rdfrom the experimental results for all specimen sizes ranged from 10.38% to 17.37%. The percentage difference of Mb,Rdof the experimental and design values based on manual calculation by using Eurocode 3 ranged from 9.13% to 43.8%.

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Finite Element Analysis of Lateral Torsional Buckling Behaviour of Tapered Steel Section with Perforation

MATEC Web of Conferences ◽

10.1051/matecconf/20164702020 ◽

2016 ◽

Vol 47 ◽

pp. 02020 ◽

Cited By ~ 1

Author(s):

Nurfarhah Naaim ◽

Fatimah De’nan ◽

Choong Kok Keong ◽

Faiz Azar

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Lateral Torsional Buckling ◽

Torsional Buckling ◽

Element Analysis ◽

Steel Section

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Experimental Study on the Lateral Torsional Buckling Behaviour of the Triangular Web Profile Steel Section

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/864/1/012046 ◽

2020 ◽

Vol 864 ◽

pp. 012046

Author(s):

Fatimah De’nan ◽

Hassyima Mat Yusof ◽

Amarpreet Kaur

Keyword(s):

Experimental Study ◽

Lateral Torsional Buckling ◽

Torsional Buckling ◽

Steel Section

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Fire behaviour and resistance of cold-formed steel beams with sigma cross-sections

Journal of Structural Fire Engineering ◽

10.1108/jsfe-11-2020-0037 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Flávio Arrais ◽

Nuno Lopes ◽

Paulo Vila Real

Keyword(s):

Numerical Analysis ◽

Cross Section ◽

Cross Sections ◽

Failure Modes ◽

Elevated Temperatures ◽

Numerical Results ◽

Lateral Torsional Buckling ◽

Torsional Buckling ◽

Content Type ◽

Finite Element Software

PurposeSigma cross-section profiles are often chosen for their lightness and ability to support large spans, offering a favourable bending resistance. However, they are more susceptible to local, distortional and lateral-torsional buckling, as possible failure modes when compared to common I-sections and hollow cross-sections. However, the instability phenomena associated to these members are not completely understood in fire situation. Therefore, the purpose of this study is to analyse the behaviour of beams composed of cold-formed sigma sections at elevated temperatures.Design/methodology/approachThis study presents a numerical analysis, using advanced methods by applying the finite element software SAFIR. A numerical analysis of the behaviour of simply supported cold-formed sigma beams in the case of fire is presented considering different cross-section slenderness values, elevated temperatures, steel grades and bending moment diagrams. Comparisons are made between the obtained numerically ultimate bending capacities and the design bending resistances from Eurocode 3 Part 1–2 rules and its respective French National Annex (FN Annex).FindingsThe current design expressions revealed to be over conservative when compared with the obtained numerical results. It was possible to observe that the FN Annex is less conservative than the general prescriptions, the first having a better agreement with the numerical results.Originality/valueFollowing the previous comparisons, new fire design formulae are analysed. This new methodology, which introduces minimum changes in the existing formulae, provides at the same time safety and accuracy when compared to the numerical results, considering the occurrence of local, distortional and lateral-torsional buckling phenomena in these members at elevated temperatures.

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The effects of residual stresses and strains on lateral-torsional buckling behavior of cold-formed steel channel and built-up I-sections beams

International Journal of Structural Integrity ◽

10.1108/ijsi-07-2018-0044 ◽

2019 ◽

Vol 10 (2) ◽

pp. 230-243

Author(s):

Mohammad Zaman Kabir ◽

Mehdi Parvizi

Keyword(s):

Residual Stresses ◽

Major Effect ◽

Buckling Analysis ◽

Roll Forming ◽

Lateral Torsional Buckling ◽

Forming Process ◽

Torsional Buckling ◽

Content Type ◽

Cold Formed Steel ◽

Residual Stresses And Strains

Purpose The purpose of this paper is to focus on the influences of residual stresses which were induced during roll-forming sections on lateral-torsional buckling of thin-walled cold-formed steel channel and built-up I-sections beams. Built-up I section is made up of two back-to-back cold-formed channel beams. In this direction, at the primary stage, the roll-forming process of a channel section was simulated in ABAQUS environment and the accuracy of the result was verified with those existing experiments. Residual stresses and strains in both longitudinal and circumferential transverse directions were extracted and considered in the lateral-torsional buckling analysis under uniform end moments. The contribution of the current research is devoted to the numerical simulation of the rolling process in ABAQUS software enabling to restore the remaining stresses and strains for the buckling analysis in the identical software. The results showed that the residual stresses decrease considerably the lateral-torsional buckling strength as they have a major impact on short-span beams for channel sections and larger span for built-up I sections. The obtained moment capacity from the buckling analysis was compared to the predictions by American Iron and Steel Institute design code and it is found to be conservative. Design/methodology/approach This paper has explained a numerical study on the roll-forming process of a channel section and member moment capacities related to the lateral-torsional buckling of the rolled form channel and built-up I-sections beams under uniform bending about its major axis. It has also investigated the effects of residual stresses and strains on the behaviour of this buckling mode. Findings The residuals decrease the moment capacities of the channel beams and have major effect on shorter spans and also increase the local buckling strength of compression flange. But the residuals have major effect on larger spans for built-up I sections. It could be seen that the ratio of moment (with residuals and without residuals) for singly symmetric sections is more pronounced than doubly symmetric sections. So it is recommended to use doubly symmetric section of cold-formed section beams. Originality/value The incorporation of residual stresses and strains in the process of numerical simulation of rolled forming of cold-formed steel sections under end moments is the main contribution of the current work. The effect of residual stresses and strains on the lateral-torsional buckling is, for the first time, addressed in the paper.

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