Did you know that you could use Consteel to perform local and distortional buckling checks for cold-formed members?

First, sections must be loaded into the model. To load cold-formed sections, you can choose from four options: From library, Macro section, Draw section, or My library.

After the first-order and buckling analyses are completed, you can proceed to the Ultimate limit state check settings and enable the steel design cross-section and buckling checks. At the bottom of the steel design section, there is an option to Consider the supplementary rules from EN 1993-1-3 for the design of cold-formed sections. This checkbox must be selected if you want to design cold-formed sections.

When the calculation is finished, by opening the Section module, we can review all the properties of the Effective section of the elastic plate segment model. By opening each plate element, we can verify the length, effective length, thickness, effective thickness, slenderness, and reduction factor separately. In addition, the properties of the stiffeners can also be verified: area, moment of inertia, lateral spring stiffness, critical stress, reduction factor, compressive stress, reduced effective area, and reduced thickness.

Similarly, the stresses can also be checked from the Properties tab. In the colored figure or diagram view, all the calculated stresses can be seen together with their resultants.

Consteel automatically takes into account the effect of distortional buckling when calculating the effective sections of cold-formed thin-walled sections.

Moving on to the Standard resistance tab in the Section module, all calculated results can be verified, not only the dominant one. By opening the Global stability resistance check, we can see that, since we enabled the option to consider the supplementary rules from EN 1993-1-3 for the design of cold-formed sections, results are available both according to EN 1993-1-1 and according to EN 1993-1-3.

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Did you know that you could use Consteel to calculate effective cross-section properties for Class 4 sections?

The classification of cross-sections is used to understand how local buckling affects the strength and rotation capacity of structural members. As stated in Eurocode 3 (EN 1993-3-3, Section 5.5), this classification helps determine whether a cross-section can reach its full resistance or if its behavior is limited by local instability.

Class 4 cross-sections are those in which local buckling occurs before the material reaches the yield stress in one or more parts. Because of this, their resistance must be calculated using effective section properties that take into account the reduction caused by local buckling.

Typical Class 4 sections are characterized by slender elements with high width-to-thickness ratios. These commonly include thin webs or flanges, hollow sections (RHS/CHS) with slender walls, thin-walled cold-formed profiles such as C- or L-sections, and welded I-sections with slender webs. In this example, we consider a welded I-section with the following geometric parameters:

In Consteel, we can then see the section classification from the Global Checks tab. After selecting the investigated section either in the model or from the table and clicking on the Calculate Section option, and then choosing the Plate Classes in the Properties tab.

The effective section properties can then be viewed using the second option in the Properties tab.

In addition, stresses can be visualized by clicking on the Stresses icon. They can be represented either as a colored figure or as a 3D diagram.

For Class 4 sections, the Standard Resistance tab in the section module provides a complete assessment for the selected loading case.

The section module performs all necessary calculations according to the Eurocode (EN 1993-1-1 and relevant parts of EN 1993-1-5), including general elastic resistance, pure case resistance, conservative interaction checks, and web buckling analysis.

All resistances are calculated using the effective section properties to account for local buckling, and the module identifies the dominant case to ensure all relevant checks are covered.

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If you haven’t tried Consteel yet, request a trial for free!

Introduction

In Consteel a great variety of EN National Annexes can be used for structural design. It is possible to review the existing annexes in the Standards menu. In case you can not find the annex you need, you are still able to define a new, custom one in an easy way.

How it works

The following annexes are available in Consteel 19:

EN Recommended, Hungarian, Dutch, Finnish, Singapore, Portuguese, Swedish, Austrian, Polish, German, Bulgarian, Greek, Cyprian, UK, Croatian, French and Danish. Spanish, Italian and Romanian standards are EN-conform codes but not officially NA’s.

By selecting a standard on the left side of the Standards dialog, all of the parameters, combination factors, safety factors can be checked by chapters.

If a user defined annex is necessary, it can be created by selecting the existing annex which is the most similar in parameters to our needs, and then by clicking the New button on the bottom left side of the dialog. With this action a user defined annex is generated having the same parameters as the selected annex before. The difference is that the parameters of the copy are editable, and so the necessary set of parameters can be used for the design.

After introducing the Eurocode standards several theses have been published on the now much-discussed phenomenon of lateral-torsional buckling of steel structural elements under pure bending. According to that, researchers are working on the development of such new design methods which can solve the problems of the design formulae given by the EN 1993-1-1. This paper gives a detailed review of the proposals for novel hand calculation procedures for the prediction of LT buckling resistance of beams. Nowadays, the application of structural design softwares in practical engineering becomes more common and widespread. Recognizing this growing interest, the main objective of our research work is the development of a novel, computer-aided design method. In this paper, the details of a general type stability design procedure for the determination of the LT buckling resistance of members under pure bending are introduced. Here, the theoretical basis of the proposed method is clarified, the calculation procedure is detailed and some results for the evaluation of the appropriateness of the method are also presented. Based on the evaluations it can be stated that the new, general type design method is properly accurate and has several advantages on the stability check of beams under bending

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In the second article of this series, Dr József Szalai of ConSteel Solutions demonstrates practical examples where the “General Method” of EN 1993-1-1 shows advantages compared to the conventional approaches.

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Clause 6.3.4 of EN 1993-1-1 describes a “General Method” for lateral and lateral torsional buckling of structural components, ideally suited to software applications. Although the UK National Annex places some limitations on the use of this method, it is possible that the approach will become more widely used.

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The new versions of the EN 1993-1-1 (EC3-1-1) and the EN 1993-1-5 (EC3-1-5) standards have introduced the general method designing beam-column structures; see [1] and [2]. The design method requires 3D geometric model and finite element analysis. In a series of papers we present this general design approach. The parts of the series are the following:

• Part 1: 3D model based analysis using general beam-column FEM

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The new versions of the EN 1993-1-1 (EC3-1-1) and the EN 1993-1-5 (EC3-1-5) standards have introduced the general method designing beam-column structures; see [1] and [2]. The design method requires 3D geometric model and finite element analysis. In a series of papers we present this general design approach. The parts of the series are the following:
– Part 0: An explanatory introduction

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Click the button bellow to download and read the full article. The article is in czech at page 48-57.

The portal frames composed of tapered welded I-shaped structural members play important roles in the industrial buildings. The application of the relatively thin plates and the optimized fabrication makes these structures being competitive against the light truss structures at least in the range of 24–36 meters span. Competition has resulted in lesser selfweights using thin plated slender cross-sections, which are sensitive to local buckling. However, the development of structures concerning local buckling was delayed in Hungary by the conservative specifications of the MSz 15024 standard. The application of the new EN 1993 standard may cause radical development in the design of tapered structural elements with relatively thin plates. This paper introduces the methods as well as the advantages of the new design methodology.

Clich the button below to download and read the full article. The article is in hungarian at page 42-55.