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

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

scholarly journals A comparative study of beam design curves against lateral torsional buckling using AISC, EC and SP

2019 ◽  
Vol 15 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Vera V Galishnikova ◽  
Tesfaldet H Gebre
Keyword(s):  
Steel Structures ◽  
Reduction Factor ◽  
Steel Beams ◽  
Steel Beam ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Vertical Loading ◽  
Beam Design ◽  
Overall Stability

Introduction. Structural stability is an essential part of design process for steel structures and checking the overall stability is very important for the determination of the optimum steel beams section. Lateral torsional buckling (LTB) normally associated with beams subject to vertical loading, buckling out of the plane of the applied loads and it is a primary consideration in the design of steel structures, consequently it may reduce the load currying capacity. Methods. There are several national codes to verify the steel beam against LTB. All specifications have different approach for the treatment of LTB and this paper is concentrated on three different methods: America Institute of Steel Construction (AISC), Eurocode (EC) and Russian Code (SP). The attention is focused to the methods of developing LTB curves and their characteristics. Results. AISC specification identifies three regimes of buckling depending on the unbraced length of the member ( Lb ). However, EC and SP utilize a reduction factor (χ LT ) to treat lateral torsional buckling problem. In general, flexural capacities according to AISC are higher than those of EC and SP for non-compact sections.

scholarly journals Effect of longitudinal stiffeners’ spacing in lateral-torsional buckling

2020 ◽  
Vol 19 (3) ◽  
pp. 190-199
Author(s):  
Néstor I. Prado ◽  
◽  
julian Carrillo ◽  
Sergio M. Pineda
Keyword(s):  
Lateral Displacement ◽  
Elastic Buckling ◽  
Flexural Capacity ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Experimental Assessment ◽  
Longitudinal Stiffeners ◽  
Simple Support ◽  
Failure Angle ◽  
Support Conditions

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.

scholarly journals Stability of Thin-Walled Beams with Lateral Continuous Restraint

2015 ◽  
Vol 15 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Ivan Balázs ◽  
Jindřich Melcher
Keyword(s):  
Critical Load ◽  
Cross Sections ◽  
Building Industry ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Load Bearing ◽  
Buckling Resistance ◽  
Resistance Assessment ◽  
Thin Walled

Abstract Metal beams of thin-walled cross-sections have been widely used in building industry as members of load-bearing structures. Their resistance is usually limited by lateral torsional buckling. It can be increased in case a beam is laterally supported by members of cladding or ceiling construction. The paper deals with possibilities of determination of critical load of thin-walled beams with lateral continuous restraint which is crucial for beam buckling resistance assessment

Calculation of Critical Lateral-Torsional Buckling Loads of Beams Subjected to Arbitrarily Transverse Loads

2019 ◽  
Vol 19 (03) ◽  
pp. 1950031 ◽  
Author(s):  
Zhenlei Chen ◽  
Jiancheng Li ◽  
Longfei Sun
Keyword(s):  
Potential Energy ◽  
Bending Moment ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Buckling Loads ◽  
Classical Energy ◽  
Transverse Loads ◽  
Novel Approach ◽  
The Difference ◽  
External Loads

This paper presents a novel approach for determining the critical lateral-torsional buckling loads of beams subjected to arbitrarily transverse loads. This new method is developed based on the classical energy method. However, the difference of the present method from the traditional energy methods is the formulation of potential energy of external loads, which is expressed in terms of the internal bending moment and internal shear force in the pre-buckling stage regardless of the type of loading. Compared to the traditional formulations of the potential energy of external loads, not only is the present formula simple in the form, easy and convenient in the calculation, but it also provides a unified form for calculating accurate critical load of lateral-torsional buckling of the beams.

Responses of PFRP Cantilevered Channel Beams under Tip Point Loads

2011 ◽  
Vol 471-472 ◽  
pp. 578-583 ◽  
Author(s):  
Jaksada Thumrongvut ◽  
Sittichai Seangatith
Keyword(s):  
Beam Theory ◽  
Point Load ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Buckling Loads ◽  
Linear Elastic ◽  
Reinforced Plastic ◽  
Modification Factor ◽  
Elastic Responses ◽  
Structural Behaviors

In this paper, the experimental results on the structural behaviors of the pultruded fiber reinforced plastic (PFRP) cantilevered channel beams under tip point load are presented. The dimensions of the beam specimens are 76 22 6, 102 29 6 and 152 43 10 mm. The span-to-depth ratios of the specimens are in the range of 10 to 46. A total of 36 specimens were tested to investigate the effect of unbraced length of the beam on the behavior of lateral-torsional buckling and buckling load. Then, the obtained buckling loads were compared to the critical buckling loads calculated by using the modified classical beam theory. From the tests, it was found that the beams have linear elastic responses up to 90-95% of their buckling loads. The mode of failure of the specimens is in the form of lateral-torsional buckling. The modified Timoshenko and Gere’s equation unsatisfactorily predicts the critical buckling loads of the beams. Finally, by using a curve fitting, a modification factor was proposed, and the obtained test results and those calculated by the proposed modified equation are in good agreement.

scholarly journals Experimental and numerical investigation of lateral torsional buckling of wood I-joists

2018 ◽  
Vol 45 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Rémi St-Amour ◽  
Ghasan Doudak
Keyword(s):  
Material Properties ◽  
Nonlinear Behavior ◽  
Fe Model ◽  
Lateral Torsional Buckling ◽  
Design Standards ◽  
Torsional Buckling ◽  
Buckling Loads ◽  
Initial Imperfections ◽  
Longitudinal Modulus ◽  
Geometric Nonlinear Analysis

This paper investigates the elastic lateral torsional buckling capacity of wood I-joists. A sensitivity analysis determined that the orthotropic material properties that affect the critical buckling load of wood I-joists are the longitudinal modulus of elasticity, the transverse shear modulus of the flanges, and the elastic modulus of the web. A 3D finite element (FE) model was developed using experimentally determined material properties and initial imperfections. The study found that FE linear predictions provided reasonable agreement with the experimental buckling loads. The FE geometric nonlinear analysis was able to replicate the experimental nonlinear behavior that was observed during the test. Comparison with contemporary North American design standards showed significant conservatism in the design approach.

Elastic Buckling Moment of Continuous Composite Beams

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.

Flexural-Torsional Buckling of Pultruded Fiber-Reinforced Polymer Angle Beams under Eccentric Loading

2020 ◽  
Vol 982 ◽  
pp. 201-206
Author(s):  
Jaksada Thumrongvut ◽  
Natthawat Pakwan ◽  
Samaporn Krathumklang
Keyword(s):  
Buckling Load ◽  
Fiber Reinforced Polymer ◽  
Width Ratio ◽  
Fiber Reinforced ◽  
Torsional Buckling ◽  
Eccentric Load ◽  
Buckling Loads ◽  
Reinforced Polymer ◽  
Cross Sectional Dimension ◽  
Flexural Torsional Buckling

In this paper, the experimental study on the pultruded fiber-reinforced polymer (pultruded FRP) angle beams subjected to transversely eccentric load are presented. A summary of critical buckling load and buckling behavior for full-scale flexure tests with various span-to-width ratios (L/b) and eccentricities are investigated, and typical failure mode are identified. Three-point flexure tests of 50 pultruded FRP angle beams are performed. The E-glass fibre/polyester resin angle specimens are tested to examine the effect of span-to-width ratio of the beams on the buckling responses and critical buckling loads. The angle specimens have the cross-sectional dimension of 76x6.4 mm with span-to-width ratios, ranging from 20 to 40. Also, four different eccentricities are investigated, ranging from 0 to ±2e. Eccentric loads are applied below the horizontal flange in increments until beam buckling occurred. Based upon the results of this study, it is found that the load and mid-span vertical deflection relationships of the angle beams are linear up to the failure. In contrast, the load and mid-span lateral deflection relationships are geometrically nonlinear. The general mode of failure is the flexural-torsional buckling. The eccentrically loaded specimens are failed at critical buckling loads lower than their concentric counterparts. Also, the quantity of eccentricity increases as buckling load decreases. In addition, it is noticed that span-to-width ratio increases, the buckling load is decreased. The eccentric location proved to have considerable influence over the buckling load of the pultruded FRP angle beams.

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