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1. ## Lateral Torsional Buckling of a Principal Beam with I-Section According to EN 1993-1-1

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This example is described in technical literature [1] as example 9.5 and in [2] as example 8.5. A lateral-torsional buckling analysis must be performed for a principal beam. This beam is a uniform structural member. Therefore, the stability analysis can be carried out according to clause 6.3.3 of DIN EN 1993-1-1. Due to the uniaxial bending, it would also be possible to perform the design by the general method according to clause 6.3.4. Additionally, the determination of the moment Mcr is validated with an idealised member model in line with the method mentioned above, using a FEM model.

2. ## Plate Buckling Analysis of Steel Shell Structures Using MNA/LBA Concept

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Shell buckling is considered to be the most recent and least explored stability issue of structural engineering. This is less due to a lack of research activities, but rather due to the complexity of the theory. With the introduction and further development of the finite element method in structural engineering practice, some engineers no longer have to deal with the complicated theory of shell buckling. Evidence of the problems and errors to which this gives rise is very well summarized in [1].

3. ## Calculating Critical Load Factor for Linear Buckling Analysis

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Buckling analysis according to the effective width method or the reduced stress method is based on the determination of the system critical load, hereinafter called LBA (linear buckling analysis). This article explains the analytical calculation of the critical load factor as well as utilisation of the finite element method (FEM).

4. ## Simplified Calculation of Critical Load According to EN 1993-1-1

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Critical load factors and the corresponding mode shapes of any structure can be efficiently determined in RFEM and RSTAB using the RF-STABILITY or RSBUCK add-on module (linear eigenvalue solver or nonlinear analysis).

5. ## Stability Analysis of Two-Dimensional Structural Components on Example of Cross-Laminated Timber Wall 3

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This article explains the alternative to the equivalent member method. It offers the option to determine internal forces of the wall susceptible to buckling according to the second-order analysis considering the imperfections and to subsequently perform the cross-section design for bending and compression.

6. ## Stability Analysis of Two-Dimensional Structural Components on Example of Cross-Laminated Timber Wall 2

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The following article describes design using the equivalent member method according to [1] Section 6.3.2, performed on the example of cross-laminated timber wall susceptible to buckling described in Part 1 of this article series. The buckling analysis will be performed as a compressive stress analysis with reduced compressive strength. For this, the instability factor kc is determined, which depends primarily on the component slenderness and the support type.

7. ## Stability Analysis of Two-Dimensional Structural Components on Example of Cross-Laminated Timber Wall 1

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Basically, you can design structural components made of cross-laminated timber in the RF-LAMINATE add-on module. Since the design is a pure elastic stress analysis, it is necessary to additionally consider the stability issues (flexural buckling and lateral-torsional buckling).

8. ## Determining and Using Effective Lengths

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The RF‑STABILITY and RSBUCK add‑on modules for RFEM and RSTAB allows you to perform eigenvalue analysis for frame structures in order to determine critical load factors including the buckling modes. It is possible to determine several buckling modes. They provide information about the model areas bearing stability risks.

9. ## Critical Load Factor of Tapered Steel Frame 3: FE Model and RF-STABILITY

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The following post verifies the determined mode shapes or critical load factors of the previous beam structures using an FE model in RFEM (surface elements) and RF‑STABILITY.

10. ## Specifics of Using Tension Members 2

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The previous post on this topic describes instabilities that may occur when using tension members. The example shown refers primarily to wall stiffening. Now, instability error messages can also refer to nodes within the range of supports. Especially truss girders and support trusses are susceptible to this. So what causes the instability here?

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