J. Szalai

7004854961

Publications - 7

The overall imperfection method for fire design situation

Samer Nemer Ferenc Papp J. Szalai

Publication Name: Engineering Structures

Publication Date: 2023-05-15

Volume: 283

Issue: Unknown

Page Range: Unknown

Description:

In this paper the Overall Imperfection Method, which is a well validated method for the assessment of the global stability resistance of thin-walled steel structural members with any load and supporting conditions, is used for fire design situation. The method uses equivalent initial geometrical imperfection in the shape of relevant elastic global buckling mode. The assessment of the global stability resistance is performed by geometrically nonlinear analysis and by checking of cross-sectional resistance using reduced elastic moduli in the analysis and reduced design strength for the cross-section checking. The validation of the method is carried out through the analysis of more thousands different structural members with hot-rolled I cross-sections. The reference values for the safety study are calculated by geometrically and materially nonlinear analysis with imperfections.

Open Access: Yes

DOI: 10.1016/j.engstruct.2023.115884

Frame Design Using Nonprismatic Members – Satisfying the Need for Speed

B. Vaszilievits-Sömjén J. Szalai Donald W. White

Publication Name: Proceedings of the Annual Stability Conference Structural Stability Research Council Ssrc 2023

Publication Date: 2023-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

This paper discusses a combination of best practices and procedures from recent work in Europe and the US, providing rational and economical calculations addressing the complexities associated with frame design using nonprismatic members. Recommendations are provided in the context of US design practice. A primary objective is to achieve maximum simplicity, transparency, and design speed while facilitating rigor of the underlying calculations. The paper provides several focused examples illustrating the recommended design verification procedures.

Open Access: Yes

DOI: DOI not available

Validation of the Overall Stability Design Methods (OSDM) for tapered members

G. Hajdú Ferenc Papp J. Szalai

Publication Name: Sdss 2019 International Colloquium on Stability and Ductility of Steel Structures

Publication Date: 2019-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Two new stability design methods are demonstrated and validated: the Overall Strength Reduction Method (OSRM) and the Overall Imperfection Method (OIM). Both methods are based on the linear buckling analysis (LBA) of global structural models and use the standard reduction curves. The OSRM is formulated in the classic way using generalized slenderness and reduction factors while the OIM uses equivalent amplitude for the buckling mode based geometrical imperfection. These new design methods cover all types of buckling modes, which can be calculated by LBA of structural models composed of tapered members with arbitrary support conditions and subjected to any complex loading. This paper clarifies the mechanical interpretation and proper calculation of all the components of the two methods in case of tapered members with arbitrary support conditions. The validation is performed on GMNIA results for several different buckling situations of tapered members proving the accuracy of the OSDM.

Open Access: Yes

DOI: DOI not available

Validation of the overall stability design methods (OSDM) for tapered members

G. Hajdú Ferenc Papp J. Szalai

Publication Name: Stability and Ductility of Steel Structures Proceedings of the International Colloquia on Stability and Ductility of Steel Structures 2019

Publication Date: 2019-01-01

Volume: Unknown

Issue: Unknown

Page Range: 1111-1119

Description:

Two new stability design methods are demonstrated and validated: the Overall Strength Reduction Method (OSRM) and the Overall Imperfection Method (OIM). Both methods are based on the linear buckling analysis (LBA) of global structural models and use the standard reduction curves. The OSRM is formulated in the classic way using generalized slenderness and reduction factors while the OIM uses equivalent amplitude for the buckling mode based geometrical imperfection. These new design methods cover all types of buckling modes, which can be calculated by LBA of structural models composed of tapered members with arbitrary support conditions and subjected to any complex loading. This paper clarifies the mechanical interpretation and proper calculation of all the components of the two methods in case of tapered members with arbitrary support conditions. The validation is performed on GMNIA results for several different buckling situations of tapered members proving the accuracy of the OSDM.

Open Access: Yes

DOI: DOI not available

Warping transfer superelement model for bolted end-plate connections subject to 3D loads

B. Vaszilievits-Sömjén M. Movahedi Rad J. Szalai

Publication Name: Stability and Ductility of Steel Structures Proceedings of the International Colloquia on Stability and Ductility of Steel Structures 2019

Publication Date: 2019-01-01

Volume: Unknown

Issue: Unknown

Page Range: 1210-1217

Description:

A simple beam element based modelling technique has been developed which makes possible to analyze frames made of I sections with column-rafter bolted end-plate connections, subject to 3D loads, compatible with the thin walled beam theory with 7DOF beam elements. The model previously developed by the same team for welded connections has been ex-tended with the addition of linear spring elements to model the bolts located at the upper and lower beam flange level. The spring stiffnesses are calculated based on the extension of the Eurocode component method and verified by simulations performed with FEA software Abaqus.

Open Access: Yes

DOI: DOI not available

Warping transfer superelement model for bolted end-plate connections subject to 3D loads

B. Vaszilievits-Sömjén M. Movahedi Rad J. Szalai

Publication Name: Sdss 2019 International Colloquium on Stability and Ductility of Steel Structures

Publication Date: 2019-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

A simple beam element based modelling technique has been developed which makes possible to analyze frames made of I sections with column-rafter bolted end-plate connections, subject to 3D loads, compatible with the thin walled beam theory with 7DOF beam elements. The model previously developed by the same team for welded connections has been extended with the addition of linear spring elements to model the bolts located at the upper and lower beam flange level. The spring stiffnesses are calculated based on the extension of the Eurocode component method and verified by simulations performed with FEA software Abaqus.

Open Access: Yes

DOI: DOI not available

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