scholarly journals Analisis Nonlinier Tekuk Torsi Lateral pada Balok Baja Cellular

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. 

Numerical Analysis of the Web Distortion’s Influence in the Lateral-Torsional Buckling of I-Sections

2017 ◽  
Vol 6 (1) ◽  
pp. 66
Author(s):  
Carla Cristiane Silva ◽  
Ricardo Hallal Fakury ◽  
Ana Lydia Reis de Castro e Silva
Keyword(s):  
Numerical Analysis ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
The Web

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 Dimensionless Analytical Solution and New Design Formula for Lateral-Torsional Buckling of I-Beams under Linear Distributed Moment via Linear Stability Theory

2017 ◽  
Vol 2017 ◽  
pp. 1-23 ◽  
Author(s):  
Wen-Fu Zhang ◽  
Ying-Chun Liu ◽  
Ke-Shan Chen ◽  
Yun Deng
Keyword(s):  
Analytical Solution ◽  
Linear Stability ◽  
Stability Theory ◽  
Numerical Solutions ◽  
Beam Theory ◽  
Linear Stability Theory ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Design Formula ◽  
Critical Moment

Even for the doubly symmetric I-beams under linear distributed moment, the design formulas given by codes of different countries are quite different. This paper will derive a dimensionless analytical solution via linear stability theory and propose a new design formula of the critical moment of the lateral-torsional buckling (LTB) of the simply supported I-beams under linear distributed moment. Firstly, the assumptions of linear stability theory are reviewed, the dispute concerning the LTB energy equation is introduced, and then the thinking of Plate-Beam Theory, which can be used to fully resolve the challenge presented by Ojalvo, is presented briefly; secondly, by introducing the new dimensionless coefficient of lateral deflection, the new dimensionless critical moment and Wagner’s coefficient are derived naturally from the total potential energy. With these independent parameters, the new dimensionless analytical buckling equation is obtained; thirdly, the convergence performance of the dimensionless analytical solution is discussed by numerical solutions and its correctness is verified by the numerical results given by ANSYS; finally, a new trilinear mathematical model is proposed as the benchmark of formulating the design formula and, with the help of 1stOpt software, the four coefficients used in the proposed dimensionless design formula are determined.

Lateral Torsional Buckling of Split Aluminium Mullion

2016 ◽  
Vol 710 ◽  
pp. 445-450 ◽  
Author(s):  
Davor Skejić ◽  
Mladen Lukić ◽  
Nebojša Buljan ◽  
Hrvoje Vido
Keyword(s):  
Structural Material ◽  
Cross Sections ◽  
Analytical Methods ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Curtain Wall ◽  
Conservative Method ◽  
Critical Moment ◽  
Fem Modelling ◽  
Complex Process

Curtain wall industry is the major user of aluminium as a structural material in buildings, with two basic curtain wall systems: stick and unitised. The latter is preassembled in shops, with the main feature that frame profiles are split in two interlocking halves. Such cross sections are complex, open and prone to lateral torsional buckling. General formulas for the calculation of elastic critical moment for lateral-torsional buckling are provided in the EN 1999-1-1, with a long and complicated procedure for non-symmetrical sections which makes it pretty impractical for everyday use. The problem of such sections can also be assessed by FEM modelling, which is a time consuming and complex process. Curtain wall industry is in a need of a swift, if approximate and conservative, method for checking the risk of lateral torsional buckling of profiles with non-symmetrical cross sections. Some available analytical methods are applied on a practical example and their results compared to those obtained using FEM modelling.

scholarly journals Elastic Critical Moment for the Lateral–Torsional Buckling (LTB) Analysis of Structural Glass Beams with Discrete Mechanical Lateral Restraints

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2492 ◽  
Author(s):  
Dario Santo ◽  
Silvana Mattei ◽  
Chiara Bedon
Keyword(s):  
Finite Element ◽  
Practical Interest ◽  
Accurate Estimation ◽  
Structural Glass ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Additional Advantage ◽  
Design Recommendations ◽  
Critical Moment ◽  
Analytical Approaches

Structural glass beams and fins are largely used in buildings, in the form of primary load-bearing members and bracing systems for roof or facade panels. Several loading and boundary conditions can be efficiently solved by means of bonded composites that involve the use of laminated glass sections. Additionally, the so-obtained glass members are often characterized by high slenderness. To this aim, several literature studies were dedicated to the lateral–torsional buckling (LTB) behavior of laterally unrestrained (LU) glass elements, with the support of full-scale experiments, analytical models, or finite element (FE) numerical investigations. Standardized design recommendations for LU glass members in LTB are available for designers. However, several design issues still require “ad hoc” (and often expensive) calculation studies. In most of the cases, for example, the mechanical interaction between the structural components to verify involves various typologies of joints, including continuous sealant connections, mechanical point fixings, or hybrid solutions. As a result, an accurate estimation of the theoretical LTB critical moment for such a kind of laterally restrained (LR) element represents a first key issue toward the definition and calibration of generalized design recommendations. Careful consideration should be spent for the description of the intrinsic features of materials in use, as well as for a combination of geometrical and mechanical aspects (i.e., geometry, number, position of restraints, etc.). In this paper, the attention is focused on the calculation of the elastic critical buckling moment of LR glass beams in LTB. Existing analytical approaches of the literature (mostly developed for steel constructional members) are briefly recalled. An additional advantage for extended parametric calculations is then taken from finite element (FE) numerical analyses, which are performed via the LTBeam or the ABAQUS software codes. The actual role and the effect of discrete mechanical restraints are, thus, explored for selected configurations of practical interest. Finally, the reliability of simplified calculation approaches is assessed.

scholarly journals The Collapse Analysis of the Lateral-Torsional Buckling of I-Shaped Stepped Steel Beams

2020 ◽  
Vol 6 (3) ◽  
pp. 295
Author(s):  
Kelsen Trista Kweenisky ◽  
Naomi Pratiwi ◽  
Paulus Karta Wijaya
Keyword(s):  
Plate Thickness ◽  
Maximum Amplitude ◽  
Cover Plate ◽  
Steel Beams ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Beam Shape ◽  
Critical Moment ◽  
Stepped Beam ◽  
Collapse Analysis

The use of a non-prismatic member such as a stepped beam as a design method has the ability to function as a tool for steel beams optimization. A cover plate is partially welded on the upper and lower flange of the member at the maximum bending moment location to increase its flexural strength and, under critical load, flexural members bend about its strong axis, displace to the lateral direction, and twist coincidentally through a phenomenon known as the Lateral-Torsional Buckling (LTB). There is, however, no equations in the AISC 360-16 specification to calculate the critical moment of a stepped beam (Mst). Therefore, this research focuses on developing Mst for a simply supported stepped beam which deforms on its shear center under static-transverse loading through the use of a collapse analysis and the behavior of the beam. The results showed the welded cover plates consequently increased the LTB resistance of the prismatic I-shaped steel beam from 9.8% to 202% while the critical moment increased more significantly with an increment in the ratio of the cover plate length to the unbraced length (α). The cover plate thickness was observed to have dominantly affected only a large α ratio while the post-buckling characteristic of large α showed a sudden collapse phenomenon. Furthermore, the LTB modification factor was generated in this study due to the initial geometrical imperfection from the first mode of Eigen shape with maximum amplitude Lb/2000 (Cb1) and stepped beam shape (Cst) which were required to estimate the critical moment of a stepped beam based on the AISC equation for a prismatic beam.

scholarly journals Strength of Flanged and Plain Cruciform Members

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Nicholas Harris ◽  
Girum Urgessa
Keyword(s):  
Rectangular Plates ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Euler Buckling ◽  
Numerical Studies ◽  
Compression Members ◽  
Different Types ◽  
Hot Rolled ◽  
The Web

There are two different types of cruciform members used in practice. Flanged cruciform sections are typically fabricated from two hot-rolled WT sections welded to the web of a standard hot-rolled I section, whereas plain cruciform sections are typically fabricated from two symmetric rectangular plates welded in the form of a cross. Cruciform members that are subjected to combined compression and bending are typically limited by torsional buckling unlike conventional compression members (such as W-shapes) that are typically limited by flexural (Euler) buckling about their local weak axis of bending. Detailed guidance on the analysis of flanged and plain cruciform members is scarce in literature. Hence, this paper presents numerical studies on the strength capacities of both flanged and plain cruciform members that are subjected to combined compression and bending effects. Analysis results show the ability of flanged and plain cruciform to resist lateral-torsional buckling over longer unbraced lengths, allowing development of efficient plastic resistance.

scholarly journals Effect of Eccentric Lateral Bracing Stiffness on Lateral Torsional Buckling Resistance of Wooden Beams

2018 ◽  
Vol 18 (02) ◽  
pp. 1850027 ◽  
Author(s):  
Ye Hu ◽  
Magdi Mohareb ◽  
Ghasan Doudak
Keyword(s):  
Threshold Value ◽  
Point Load ◽  
Symmetric Mode ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Buckling Modes ◽  
Buckling Resistance ◽  
Load Height ◽  
Lateral Bracing ◽  
Critical Moments

An energy-based solution is developed for the lateral torsional buckling (LTB) analysis of wooden beams with flexible mid-span lateral bracing offset from section mid-height and subjected to uniformly distributed or mid-span point load. The study shows that such beams are prone to two potential buckling modes; symmetric or anti-symmetric. The symmetric mode is shown to govern the capacity of the beam for low bracing stiffness while the anti-symmetric mode governs the capacity when the bracing stiffness exceeds a threshold value. Using the present formulation, the threshold bracing stiffness required to suppress the symmetric mode and maximize the critical moments is directly obtained by solving a special eigenvalue problem in the unknown bracing stiffness. The technique thus eliminates the need for trial and error in standard solutions. A parametric study is conducted to investigate the effect of bracing height, load height, and bracing stiffness on the critical moments. A large database of runs is generated and used to develop simple expressions for determining the threshold bracing stiffness required to maximize the elastic LTB resistance.

scholarly journals Lateral Torsional Buckling of Steel Beams Elastically Restrained at the Support Nodes

2019 ◽  
Vol 9 (9) ◽  
pp. 1944
Author(s):  
Rafał Piotrowski ◽  
Andrzej Szychowski
Keyword(s):  
Twist Angle ◽  
Major Axis ◽  
Steel Beams ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Critical Moment ◽  
Simple Physical Interpretation ◽  
Approximation Formulas ◽  
Lateral Rotation ◽  
Elastically Restrained

The study shows the results of theoretical investigations into lateral torsional buckling of bisymmetric I-beams elastically restrained against warping and against rotation in the plane of lateral torsional buckling (i.e., against lateral rotation) at the support nodes. The analysis accounted for the whole variation range of node stiffnesses, from complete warping freedom to full restraint, and from complete lateral rotation freedom to full restraint. It was assumed the beams are simply supported against bending about the major axis of the section. To determine the critical moment, the energy method was used. Both the twist angle function and the lateral deflection function of the beam were described using power polynomials with simple physical interpretation. Computer programmes were developed to make numerical and symbolic “computations”. General approximation formulas for the critical moment for lateral torsional buckling were derived. The formulas covered the basic and most frequently found loading diagrams. Detailed computations were performed for different values of the index of fixity against warping and against rotation in the plane of lateral torsional buckling. The critical moments determined using the programmes devised and approximation formulas were compared with the values obtained with LTBeam software (FEM). A very good congruence of results was found.

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