A. Rubert

56412800300

Publications - 4

Out-of-plane buckling resistance of members with monosymmetric I-section according to prEN 1993–1–1:2020

A. Rubert G. Hajdú

Publication Name: Bauingenieur

Publication Date: 2022-01-01

Volume: 97

Issue: 6

Page Range: 173-185

Description:

In this paper, the stability resistance of beam-columns with monosymmetric I-section are examined according to prEN 1993–1–1:2020 standard. The buckling behaviour of the members with monosymmetric I-section is different from doubly symmetric cross-section because the eccentricity between the shear centre and centre of gravity causes additional second-order bending moments and second-order bimoment from compression. This paper aims to show a comparison between the results of the Interaction Method, General Method and the Overall Imperfection Method. To investigate the accuracy of the above-mentioned design methods several geometrically and materially nonlinear analyses with imperfections (also known as GMNIA) were carried out by the authors. The parametric study showed that the different methods have similar safety level in the investigated cases.

Open Access: Yes

DOI: 10.37544/0005-6650-2022-06-33

Eigenshape based imperfection method for beam-columns with mono-symmetric I-sections

A. Rubert G. Hajdú

Publication Name: Stahlbau

Publication Date: 2021-08-01

Volume: 90

Issue: 8

Page Range: 600-613

Description:

Eigenshape based imperfection method for beam-columns with mono-symmetric I-sections. This paper shows for the first time the application of the Overall Imperfection Method (OIM) for columns, beams and beam-columns with mono-symmetric I cross-section. The buckling failure mode of compressed members with mono-symmetric I-section is torsional-flexural like. The second-order effect from the rotation around the longitudinal shear axis during the loss of stability is taken into account when the amplitude of the initial imperfection is calculated for the compressed members. For beams, the buckling behaviour is also different from doubly symmetric cross-section because the shear centre and the centre of gravity of the cross-section do not meet at the same position. This paper shows the extension and the usability of the OIM for steel structures with mono-symmetric I-section. The automatic determination of the equivalent amplitudes for columns, beams and beam-columns are presented for the first time. The practicality of the proposed method is demonstrated for single and multi-span members with three examples.

Open Access: Yes

DOI: 10.1002/stab.202100017

Overall imperfection method for flexure and compression steel beam-columns

A. Rubert G. Hajdú Ferenc Papp

Publication Name: Stahlbau

Publication Date: 2017-06-01

Volume: 86

Issue: 6

Page Range: 483-496

Description:

Overall imperfection method for flexure and compression steel beam-columns. The principles and applications of the overall (global) imperfection method (OIM) for beam-columns are presented in this paper. The buckling resistance of a beam-column member is determined by the resistance of its critical cross-section taking into account second-order effect of the eigenform equivalent initial imperfection. The maximum amplitude of this initial imperfection, in the shape of elastic buckling mode, is determined from fundamental cases, which are simply fork supported members with uniform cross-section under uniformly distributed normal force or bending moment. The standardized buckling resistance of the fundamental cases is based on theoretical and empirical background. The proposed global imperfection method is adequate for computer-aided design method using advanced elastic beam-column finite element method including the warping behavior of the cross section. The accuracy of the presented method is illustrated step-by-step with numerical examples.

Open Access: Yes

DOI: 10.1002/stab.201710471

Spatial stability analysis and global stability checks according to DIN EN 1993-1-1

A. Rubert Ferenc Papp J. Szalai

Publication Name: Bauingenieur

Publication Date: 2015-10-01

Volume: 90

Issue: October

Page Range: 469-477

Description:

This paper presents the spatial stability analysis and global stability checks according to the "General Method" of DIN EN 1993-1-1/clause 6.3.4 for complete steel structures of thin walled open sections. This is a software based design procedure for evaluating the global eigen-solutions (eigenvalue acrop and eigen- shape) using integrated stability analysis and standard check. It is compared to the classical method using different calculation models as well as suitable software for stress analysis and the global spatial stability analysis and check. For the numerical analysis (as it is the crucial point of the method) the 14 DOF beam-column finite element of ConSteel is used. The two examples demonstrate the very safe and uneconomic restrictions of the German NA of clause 6.3.4. According the author's experiences and [16] it is not recommended to use them.

Open Access: Yes

DOI: DOI not available