Modelling and Statistical Approaches to Lateral-Torsional Buckling

2014 ◽  
Vol 969 ◽  
pp. 259-264
Author(s):  
Zdenek Kala ◽  
Jan Valeš
Keyword(s):  
Carrying Capacity ◽  
Limit State ◽  
Random Effect ◽  
Ultimate Limit State ◽  
Load Carrying Capacity ◽  
Lateral Torsional Buckling ◽  
Random Load ◽  
Torsional Buckling ◽  
Load Carrying ◽  
Ultimate Limit

Some particular and selected problems aimed at ultimate limit state and probability-based studies pertaining to lateral-torsional buckling of steel beams are described. Stochastic analysis of the ultimate limit state of a slender member IPE220 under bending was elaborated. The values of non-dimensional slenderness for which the statistical characteristics of random load-carrying capacity are maximal were determined. The stochastic computational model was created in the programme ANSYS. Geometric nonlinear solution was employed. In the conclusion of the article, the question of the random effect of the initial rotation of the cross-section on the load-carrying capacity is discussed.

Load-Carrying Capacity of Timber Structure Bolt Connection Subjected to Double Unequal Shears

2015 ◽  
Vol 752-753 ◽  
pp. 711-714 ◽  
Author(s):  
Josef Musílek ◽  
Karel Kubečka
Keyword(s):  
Carrying Capacity ◽  
Limit State ◽  
Thin Plates ◽  
Ultimate Limit State ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Timber Member ◽  
Connection Type ◽  
Bolt Connection ◽  
Ultimate Limit

The paper deals with load-carrying capacity of bolted connections subjected to unequal double shears with thin plates as outer members and inner timber member. There are derived equations which describe the load-carrying capacity of this connection type in the ultimate limit state.

APPLICATION OF UNCERTAINTY ANALYSIS TO STABILITY PROBLEMS OF STEEL-CONCRETE STRUCTURAL MEMBERS

2009 ◽  
Vol 1 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Libor Puklický ◽  
Zdeněk Kala
Keyword(s):  
Epistemic Uncertainty ◽  
Limit State ◽  
Ultimate Limit State ◽  
Load Carrying Capacity ◽  
Structural Members ◽  
Load Carrying ◽  
Steel Sections ◽  
Limit Stress ◽  
Ultimate Limit

The paper deals with the fuzzy analysis of the ultimate limit state of a steel strut with an encased web in compression. The first part of the paper lists presumptions required for the determination of the theoretical load carrying capacity for the column. Stresses in the concrete and steel sections are determined according to the principles of elasticity. The ultimate limit state is given as the limit stress attained in the most stressed section of either the steel or concrete section. A general extended principle, which takes into account the epistemic uncertainty of input parameters, was utilized for the conducted analysis.

scholarly journals RELIABILITY ANALYSIS OF THE LATERAL TORSIONAL BUCKLING RESISTANCE AND THE ULTIMATE LIMIT STATE OF STEEL BEAMS WITH RANDOM IMPERFECTIONS

2015 ◽  
Vol 21 (7) ◽  
pp. 902-911 ◽  
Author(s):  
Zdeněk Kala
Keyword(s):  
Failure Probability ◽  
Limit State ◽  
Ultimate Limit State ◽  
Safety Factors ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Random Variability ◽  
Partial Safety Factors ◽  
Ultimate Limit

The paper deals with the analysis of reliability of a hot-rolled steel IPE-beam designed according to Eurocodes. A beam at its ultimate limit state is considered. The load acting on the beam consists of permanent and long-term single variation actions. The beam is loaded with end bending moments about the major principal axis. The beam is susceptible to lateral torsional buckling between the end supports. Reliability of the beam is assessed using probabilistic analysis based on the Monte Carlo method. Failure probability is a function of the random variability of the loadcarrying capacity and the random variability of load effects. The variability of the load-carrying capacity is influenced by the variability of initial imperfections. Imperfections are considered according to experimental research. Numerical studies showed that the failure probability is significantly misaligned. High values of failure probability were obtained for slender beams, for beams loaded only by permanent load action, and for beams loaded only by long-term single variation load. In further studies the values of partial safety factors of load and resistance were calibrated so that the failure probability had a target value of 7.2E–5. Relatively high values of partial safety factors were obtained especially for beams with high slenderness.

scholarly journals Inelastic Ultimate Load Analysis of Steel Frames Considering Lateral Torsional Buckling Under Distributed Loads

2019 ◽  
Author(s):  
Mutlu Secer ◽  
Ertugrul Turker Uzun
Keyword(s):  
Carrying Capacity ◽  
Ultimate Load ◽  
Steel Frames ◽  
Load Carrying Capacity ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Numerical Examples ◽  
Buckling Behavior ◽  
Load Carrying ◽  
Load Analysis

Contemporary structural design approaches necessitates ways to determine realistic behavior of structures. For this purpose, inelastic ultimate load analysis methods are used widely since strength and stability of whole structure can be represented. In this study, a numerical method is proposed for determining inelastic ultimate load capacity of steel frames considering lateral torsional buckling behavior under distributed loads. In the analyses, inelastic material behavior, second-order effects and residual stresses of the structural frame system and its members are taken into account. Additionally, lateral torsional buckling behavior is considered in the analysis using finite difference method and it is used for determining the structural load carrying capacity of steel frames. Consequently, the problem associated with flexural capacity decreases due to lateral torsional buckling is precisely considered in the load increment steps of inelastic ultimate load analysis. In order to validate the proposed method, numerical examples from the literature are calculated considering the proposed method, AISC 360-16 design specification equations and approaches from the literature. Results of the numerical examples show that lateral torsional buckling is a key issue in determining structural load carrying capacity. Thus, proposed analysis method is shown to be an efficient and consistent tool for inelastic ultimate load analysis.

scholarly journals Experimental Research on Equivalent Rectangular Opening Castellated Beam with Fillet Corner

2020 ◽  
Vol 8 (5) ◽  
pp. 5415-5420
Keyword(s):  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Rectangular Section ◽  
Flexure Mechanism ◽  
Modes Of Failure ◽  
Load Carrying ◽  
Shear Buckling ◽  
Castellated Beam

Nowadays the use of castellated beam has been admired due to its beneficial functions like a light in weight, easy to erect, economical and stronger. The castellated beam is manufactured from its parent solid I beam by cutting it in a zigzag pattern and again joining it by welding so that the depth of the beam increases. Hence, due to an increase in depth of beam load carrying capacity of the parent I section is increased with the same quantity of material and weight. The increase in depth of the castellated beam leads to web post-buckling and lateral-torsional buckling failure when these beams are subjected to loading. There are many other modes of failure like the formation of flexure mechanism, lateral-torsional buckling, and formation of Vierendeel mechanism, rupture of the welded joint in a web post and shear buckling of a web post which needs to be taken care of. Hence, in the present paper, an attempt has been made to evaluate existing literature, concerned with the strength of the beam by providing a rectangular opening and rectangular opening equivalent to diagonal & hexagonal opening with different angles of opening 300 , 450 & 600 . The fillet radius is provided to the corner of the rectangular opening as a result of a 54% increase in the load-carrying capacity of the rectangular section compared to the regular rectangular section.

Some Experiences with Evaluation of the Load Carrying Capacity of Bridges Using in Situ Load Tests

2018 ◽  
Author(s):  
Jacob Wittrup Schmidt ◽  
Arne Henriksen ◽  
Svend Engelund
Keyword(s):  
Computational Model ◽  
Carrying Capacity ◽  
Limit State ◽  
Concrete Bridges ◽  
Ultimate Limit State ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Actual Load ◽  
Load Tests

The evaluation of the load carrying capacity of bridges is usually performed using a computational model and a number of codes that specify the relevant ma terial properties and loads. This approach ensures that the evaluation of the load carrying capacity is performed such that the bridge has an acceptable level of safety with respect to a number of adverse events such as collapse (ultimate limit state) and large deformations (serviceability limit state). However, experience indicate that redistribution of load effects, interaction between structural elements, the actual boundary conditions and other factors may provide a higher load carrying capacity than the one determined on the basis of the computational model. The Danish Road Directorate has in cooperation with The Danish Technical University and COWI A/S performed a number of in situ load tests of concrete bridges in order to determine the actual load carrying capacity of the short span concrete bridges (up to 12m). The paper presents the planning and the execution of the tests. Further, it is demonstrated how the results may be used in order to determine the actual load carrying capacity of a bridge.

scholarly journals Experimental Investigation for Non and Partially Composite Cold-Formed Steel Floor Beams

2019 ◽  
Vol 5 (6) ◽  
pp. 1407-1423
Author(s):  
Tuka Mohammed Qasim ◽  
Salah Rohaima Al-Zaidee
Keyword(s):  
Carrying Capacity ◽  
Single Channel ◽  
Composite Model ◽  
Load Carrying Capacity ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Buckling Modes ◽  
The Third ◽  
Load Carrying ◽  
Cold Formed Steel

In this study, six full-scaled models of RC floors supported by cold-form steel sections have been tested. Each model consists of RC 75mm thick slab supported on two parallel cold-formed steel beams with a span of 3m and spacing of 500mm. The slab has an overhang part of 250mm on each side. In the first and fourth models, the slab has been casted directly on the top flanges with no shear connector to simulate the effectiveness of friction in resisting of the lateral-torsional buckling. Shear studs have been drilled in the second and fifth models to ensure the composite action. Finally, the flanges have been embedded for the third and sixth models. A single channel beam is used in the first, second, and third models while a built-up beam is used in the fourth, fifth, and sixth models. Each model has been loaded up to failure under a pure bending with two-line loads located at the third points. Data for loads, deformations, and strains have been gathered. Except the fourth and the sixth models that failed in local buckling modes, all other models failed in global lateral-torsional buckling modes. For the single beam models; the load carrying capacity of the non-composite model is 82.9% less than the capacity of the composite models with shear studs and embedded flange. For the built-up models; the load carrying capacity of the non-composite model is 44.2 % less than the loads of the composite model with shear stud and 48.7% less than the model with the embedded flange.

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.

Reliability analysis of wood I-joists

1993 ◽  
Vol 20 (4) ◽  
pp. 564-573 ◽  
Author(s):  
R. O. Foschi ◽  
F. Z. Yao
Keyword(s):  
Reliability Analysis ◽  
Carrying Capacity ◽  
Failure Modes ◽  
Limit State ◽  
Load Carrying Capacity ◽  
Limit States ◽  
Element Analysis ◽  
Strength Limit ◽  
Reliability Method ◽  
Load Carrying

This paper presents a reliability analysis of wood I-joists for both strength and serviceability limit states. Results are obtained from a finite element analysis coupled with a first-order reliability method. For the strength limit state of load-carrying capacity, multiple failure modes are considered, each involving the interaction of several random variables. Good agreement is achieved between the test results and the theoretical prediction of variability in load-carrying capacity. Finally, a procedure is given to obtain load-sharing adjustment factors applicable to repetitive member systems such as floors and flat roofs. Key words: reliability, limit state design, wood composites, I-joist, structural analysis.

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