Hartmut Pasternak

7004191121

Publications - 6

Shear buckling behaviour of beams with partial-depth stiffeners at the support

G. Hajdú Hartmut Pasternak

Publication Name: Thin Walled Structures

Publication Date: 2025-02-01

Volume: 207

Issue: Unknown

Page Range: Unknown

Description:

This paper presents the findings from experimental tests and numerical simulations on plate girders with various end post configurations. While EN 1993-1-5:2024 provides design rules for both rigid and non-rigid end posts, it does not address the shear resistance of partially stiffened webs. The use of partial-depth stiffeners faces risks due to the lack of thorough investigation into their mechanical behaviour. To explore this issue, small numbered experimental tests and large numbered parametric studies on beams with different web slenderness were conducted using advanced numerical simulations. The results indicated that the shear buckling capacity of girders is lower than the design recommendation when the web stiffener height is <50 % of the web height. For girders with full-height stiffeners, EN 1993-1-5:2024 yields safe results. The accuracy of the EN 1993-1-5:2024 design rule for partially stiffened beams was also evaluated and new and shear buckling design curves were proposed for girders with partial-depth stiffeners.

Open Access: Yes

DOI: 10.1016/j.tws.2024.112622

Shear buckling performance of welded I-girders with partially stiffened web at the support

G. Hajdú Hartmut Pasternak

Publication Name: Bauingenieur

Publication Date: 2025-01-01

Volume: 100

Issue: 1-2

Page Range: 21-32

Description:

This paper presents findings from tests and numerical simulations conducted on plate girders with varying end post configurations. Although EN 1993–1–5:2024 provides design guidelines for both rigid and non-rigid end posts, it does not cover the shear resistance of webs that are only partially stiffened. Partial-depth stiffeners pose potential risks due to the limited research into their mechanical behaviour. To investigate this issue, tests and parametric studies were per-formed on beams with differing web slenderness using advanced numerical simulations. EN 1993–1–5:2024 provides reliable estimates for fully stiffened beams, while new shear buckling curves have been proposed for partially stiffened beams.

Open Access: Yes

DOI: 10.37544/0005-6650-2025-01-02-55

Lateral-torsional buckling behaviour of I-beams with sinusoidally corrugated web

G. Hajdú Imre Cserpes Hartmut Pasternak

Publication Name: Bauingenieur

Publication Date: 2024-01-01

Volume: 99

Issue: 3

Page Range: 69-77

Description:

AB ST R AC T This paper presents a new approach to calculate the elastic lateral-torsional buckling moment of I-beams with sinusoidally corrugated webs. The appropriate hand calculation methods to determine the elastic critical moment of corrugated web beams have so far been based on the modification of the warping constant of the cross-section. Instead of modifying the warping constant, the corrugated web is modelled as a thin, equivalent orthotropic plate with uniform thickness. With the usage of the elastic critical moment the inelastic lateral-torsional buckling resistance of sinusoidally corrugated I-beam is determined according to the current Eurocode 1993–1–1:2005.

Open Access: Yes

DOI: 10.37544/0005-6650-2024-03-29

Lateral-torsional buckling assessment of I-beams with sinusoidally corrugated web

G. Hajdú Ferenc Papp Hartmut Pasternak

Publication Name: Journal of Constructional Steel Research

Publication Date: 2023-08-01

Volume: 207

Issue: Unknown

Page Range: Unknown

Description:

This paper assesses the elastic and inelastic lateral-torsional buckling resistance of I-beams with sinusoidal corrugated web through an extended 22 degrees of freedom thin-walled beam-column finite element method. The appropriate hand calculation methods to determine the elastic critical moment of corrugated web beams are based on the modification of the warping constant of the cross-section. Instead of modifying the warping constant, the corrugated web is modelled as a thin, equivalent orthotropic plate with uniform thickness. An approximate expression is also derived from the total potential strain energy of the beam using the Ritz method. The result of the parametric study showed that the developed finite element is accurate and applicable for linear buckling analysis of beams with sinusoidal web corrugation. With the results of the linear buckling analysis the plastic resistance of the corrugated web beam can also be determined. Based on advanced finite element simulations' results the parametric study showed that the standard-based imperfection factor leads to conservative results to predict the inelastic lateral-torsional buckling resistance of sinusoidally corrugated beams, so a more precise but still safe imperfection factor is proposed for sinusoidally corrugated web beams.

Open Access: Yes

DOI: 10.1016/j.jcsr.2023.107916

Shear Buckling Resistance of I-Beams with Partially Stiffened Webs

G. Hajdú Hartmut Pasternak

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 358-365

Description:

This paper presents the results of laboratory tests and numerical analysis for plate girders with partial height end stiffeners. Design rules for rigid end posts and non-rigid end posts are given in EN 1993-1-5:2006 but the shear resistance of partially stiffened webs is not mentioned. The use of non-tightly fitted stiffeners is hazardous due to insufficient investigations of the real behaviour. To discover this problem parametric studies on beams with different web slenderness are examined with the usage of advanced numerical simulations. The accuracy of the EN 1993-1-5:2006 standard design rule for partially stiffened beams is also examined. The results of the numerical simulations shows that the shear buckling capacity of girders is lower than the design recommendation where the height of the web stiffener is b5% of the web height. For girders with full height stiffeners the EN 1993-1-5:2006 standard leads conservative results.

Open Access: Yes

DOI: 10.3233/ATDE240567

Shear resistance of continuous steel beams with thin webs

G. Hajdú Hartmut Pasternak

Publication Name: Thin Walled Structures

Publication Date: 2026-05-01

Volume: 224

Issue: Unknown

Page Range: Unknown

Description:

The shear buckling and post-buckling behaviour of welded plated I girders with slender webs plays a critical role in the safety and economy of steel bridge and building structures. However, experimental data and validated numerical models for multi-span girders with slender webs remain limited, and the accuracy of current design provisions is not yet fully established. This paper presents the results of an experimental and numerical investigation on ten two-span welded plated I girders with transversely stiffened webs. By placing transverse stiffeners on both sides, the web panels were divided into four or eight rectangular segments with an aspect ratio of a/h=2.5. The web slenderness ratios h/t ranged from 175 to 350, while the flange slenderness ratios b/t varied between 8 and 40. The specimens exhibited shear failure governed by tension-field action near the internal support or flange buckling in the middle of the span. To further examine the shear buckling behaviour, geometrically and materially nonlinear analyses with imperfections were performed using advanced full-shell finite element models. The validated numerical models were then employed in a comprehensive parametric study covering a wide range of geometric configurations. The numerical results were used to assess the accuracy of the shear strength formula specified in EN 1993-1-5:2024 and AISC 360-22. Based on the results of the numerical simulations new formulas are proposed for the contribution of the web and flanges to determine the shear strength of plated I girders.

Open Access: Yes

DOI: 10.1016/j.tws.2026.114731