Effect of longitudinal stiffeners’ spacing in lateral-torsional buckling

This study focused on the experimental assessment of the effect of the spacing between longitudinal stiffeners welded to I-shaped beams under the action of lateral-torsional buckling. In this procedure, 192 aluminum beams on a 1:9 scale were tested under simple-support conditions with a laterally unbraced length ranging from 0.55 m through 1.95 m. Moreover, the stiffeners’ spacing was also ranged from 3 to 9 times the depth of section. The structural behavior of the beams is discussed in terms of their flexural capacity, spacing between longitudinal stiffeners, lateral displacement of compression flange and failure angle twist. Results show that the spacing of longitudinal stiffeners influences the flexural capacity of I-shaped beams, so that, when the spacing of longitudinal stiffeners decreases, flexural capacity tends to increase, especially in the elastic buckling zone.

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Experimental assessment of I-shaped steel beams with longitudinal stiffeners under lateral-torsional buckling

DYNA ◽

10.15446/dyna.v85n207.71892 ◽

2018 ◽

Vol 85 (207) ◽

pp. 278-287

Author(s):

Néstor I. Prado ◽

Julian Carrillo ◽

Gustavo A. Ospina ◽

Dario Ramirez-Amaya

Keyword(s):

Lateral Displacement ◽

Twist Angle ◽

Steel Beams ◽

Flexural Capacity ◽

Lateral Torsional Buckling ◽

Torsional Buckling ◽

Experimental Assessment ◽

Longitudinal Stiffeners ◽

Simple Support ◽

Support Conditions

This study focused on the experimental assessment of the behavior of I-shaped steel beams with longitudinal stiffeners under the action of lateral-torsional buckling. Thirty-three IPE-140 steel beams with and without longitudinal stiffeners were tested under simple-support conditions with a laterally unbraced length ranging from 0.69 to 6.0 m. The stiffeners spacing was 0.42 m, which represented three times the depth of the section. The structural behavior of the beams is discussed in terms of their flexural capacity, the lateral displacement of the compression flange and the failure twist angle. The results showed that the use of longitudinal stiffeners increased the flexural capacity up to 82%, decreased the lateral displacement of the compression flange and the failure twist angle up to 72 and 90% respectively, with respect to the specimens without stiffeners.

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Analytical Solution for Lateral-Torsional Buckling of Concrete-Filled Tubular Flange Girders with Torsional Bracing

Advances in Civil Engineering ◽

10.1155/2020/4340381 ◽

2020 ◽

Vol 2020 ◽

pp. 1-14

Author(s):

Yingchun Liu ◽

Zhaoming Hang ◽

Wenfu Zhang ◽

Keshan Chen ◽

Jing Ji

Keyword(s):

Analytical Solution ◽

Lateral Displacement ◽

Data Sets ◽

Torsional Angle ◽

The Finite Element Method ◽

Lateral Torsional Buckling ◽

Torsional Buckling ◽

Concentrated Load ◽

Buckling Strength ◽

Parametric Studies

Concrete-filled tubular flange girders have been used in bridges, and torsional bracings are widely used in them to increase the lateral-torsional buckling strength. This article proposes an analytical solution for the lateral-torsional buckling (LTB) of concrete-filled tubular flange steel girders with torsional bracing under a concentrated load. The modal trial functions of lateral displacement and the torsional angle are expressed by the first six terms of the trigonometric function. By introducing dimensionless parameters, the variational solution of energy for the buckling equation of the LTB of the girders is obtained, and the formula for the dimensionless critical moment of its LTB is derived using 1stOpt based on 32,550 data sets. Compared with the finite element method, the proposed critical formula is highly accurate and can be applied to engineering design. Finally, parametric studies were conducted on the effects of the stiffness of torsional bracing, the span of the girder, and the flange steel ratio.

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Stability Analysis of Nonuniform Rectangular Beams Using Homotopy Perturbation Method

Mathematical Problems in Engineering ◽

10.1155/2012/197483 ◽

2012 ◽

Vol 2012 ◽

pp. 1-18 ◽

Cited By ~ 5

Author(s):

Seval Pinarbasi

Keyword(s):

Stability Analysis ◽

Perturbation Method ◽

Homotopy Perturbation Method ◽

Lateral Displacement ◽

Stability Limit ◽

Variable Cross ◽

Lateral Torsional Buckling ◽

Torsional Buckling ◽

Homotopy Perturbation ◽

Beam Stability

The design of slender beams, that is, beams with large laterally unsupported lengths, is commonly controlled by stability limit states. Beam buckling, also called “lateral torsional buckling,” is different from column buckling in that a beam not only displaces laterally but also twists about its axis during buckling. The coupling between twist and lateral displacement makes stability analysis of beams more complex than that of columns. For this reason, most of the analytical studies in the literature on beam stability are concentrated on simple cases: uniform beams with ideal boundary conditions and simple loadings. This paper shows that complex beam stability problems, such as lateral torsional buckling of rectangular beams with variable cross-sections, can successfully be solved using homotopy perturbation method (HPM).

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Flexural Capacity of Locally Buckled Steel I-Beams Under Moment Gradient

The Open Construction and Building Technology Journal ◽

10.2174/1874836801307010244 ◽

2013 ◽

Vol 7 (1) ◽

pp. 244-250 ◽

Cited By ~ 1

Author(s):

Amin Mohebkhah ◽

Behrouz Chegeni

Keyword(s):

Local Buckling ◽

Element Model ◽

Nonlinear Finite Element ◽

Flexural Capacity ◽

Lateral Torsional Buckling ◽

Limit States ◽

Torsional Buckling ◽

Buckled Beams ◽

Moment Gradient ◽

Nonlinear Finite Element Model

Lateral-torsional buckling (LTB) and flange local buckling (FLB) are treated as two independent phenomena in AISC-LRFD 360-10 in which the flexural capacity of locally buckled beams is determined as the minimum value obtained for the limit states of LTB and FLB. A 3-D nonlinear finite-element model using ABAQUS is developed in this research to investigate the interactive flexural capacity of steel I-beams with compact web under moment gradient. It was found that the AISC approach is adequate for beams with compact or noncompact sections, however, too conservative for beams with slender flanges representing a considerable interaction between LTB and FLB limit states.

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Analisis Nonlinier Tekuk Torsi Lateral pada Balok Baja Cellular

MEDIA KOMUNIKASI TEKNIK SIPIL ◽

10.14710/mkts.v25i2.23674 ◽

2020 ◽

Vol 25 (2) ◽

pp. 141

Author(s):

Benny Gunawan Hung ◽

Bambang Suryoatmono

Keyword(s):

Circular Opening ◽

Lateral Deformation ◽

Maximum Difference ◽

Lateral Torsional Buckling ◽

Torsional Buckling ◽

Buckling Modes ◽

Critical Moment ◽

Design Guide ◽

Simple Support ◽

The Web

One of many buckling modes that could occur on the beam is lateral-torsional buckling. Lateral torsional buckling could result in lateral deformation and torsion of section. In the AISC 360-16 Spesification, an equation is provided to calculate lateral-torsional buckling critical moment of prismatic I section beam. For cellular beams (I section beam with circular openings), AISC Design Guide 31 states that the lateral-torsional buckling critical moment should be checked in accordance with AISC Specification using gross section properties. With this assumption, thus, the design guide ignores the existence of circular opening on the web, which can cause a reduction of lateral-torsional buckling critical moment. In this study, lateral-torsional buckling analysis on cellular beam with simple support loaded by distributed transversal load has been done - the analysis utilized finite element based software. From the analysis, the critical moment is lower than AISC 360-16 critical moment with the assumption of prismatic I section beam, with the maximum difference percentage of 43,58%. Based on this study, a correction factor has been obtained to estimate the critical moment of cellular beams by using equation on AISC 360-16.

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Determination of elastic buckling loads for lateral torsional buckling of beams including contact

International Conference of Computational Methods in Sciences and Engineering 2004 (ICCMSE 2004) ◽

10.1201/9780429081385-23 ◽

2019 ◽

pp. 91-94

Author(s):

P. Buffel ◽

G. Lagae ◽

R. Van Impe ◽

W. Vanlaere

Keyword(s):

Elastic Buckling ◽

Lateral Torsional Buckling ◽

Torsional Buckling ◽

Buckling Loads

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Elastic Buckling Moment of Continuous Composite Beams

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.691.86 ◽

2016 ◽

Vol 691 ◽

pp. 86-95

Author(s):

Tomas J. Zivner ◽

Rudolf B. Aroch ◽

Michal M. Fabry

Keyword(s):

Limit State ◽

Composite Beams ◽

Elastic Buckling ◽

Ultimate Limit State ◽

Lateral Torsional Buckling ◽

Torsional Buckling ◽

Continuous Beams ◽

Approximation Formulas ◽

Different Sources ◽

Ultimate Limit

Lateral-torsional buckling is one of the criteria in the design of steel and composite beams in ultimate limit state. This paper deals with lateral-torsional buckling of double-span continuous composite beams subjected to two different loadings. The main objective of the paper is the comparison of the elastic buckling moment values of composite continuous beams performed according to approximation formulas of Mcr,A from codes [2] and different sources [3] to more exact values Mcr,E obtained by computer programs based on finite element method [1P]. The results will be presented in the form of elastic buckling moment ratios Mcr,A / Mcr,E.

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