B. Kövesdi

Budapest University of Technology and Economics · Department of Structural Engineering

Corrosion measurements were performed on the 175-years-old historical Széchenyi Chain Bridge within the last four decades; most lately under its reconstruction process in 2022. Measurement results are evaluated, and the findings encompass the structural corrosion loss of the chain elements (eyebars). A multi-phase nonlinear corrosion model, with ti...

A temporary monitoring system was installed on the 175-year-old historical Széchenyi Chain Bridge during its reconstruction. The bridge is in the downtown area in the capital city of Hungary and plays a significant role in the city life of Budapest. Six-month-long measurements were conducted during the reconstruction process of the bridge, yielding...

In recent years, the construction industry has witnessed a growing preference for welded box-sections due to their ease of fabrication and improved stability characteristics. Nonetheless, welded box-sections are prone to various instabilities, which can be classified into three categories: global buckling, local buckling, and interactive buckling....

The application of design by finite element analysis (FEA) is becoming increasingly prevalent in applied engineering; however, codified provisions remain scarce. The vision of CEN/TC 250/SC 3 was to develop a new comprehensive document based on the existing provisions currently distributed throughout the different Eurocode 3 parts, and with extensi...

The Széchenyi chain bridge is an almost 170‐year‐old historical structure located in the downtown of Budapest, which has been reconstructed between 2020‐2022. The chain system of the bridge is more than 100 years old, and the rotational capacity of the pins is questionable due to corrosion and friction. This phenomenon significantly influences the...

High‐strength steel materials (steel grades of S500 ‐ S960) gaining prominence in civil engineering, especially for large‐span bridges. In the case of bridges, the application of hybrid girders combining low‐ and high‐strength steel materials is an effective and economical solution. The hybrid girders generally consist of webs comprised of low‐stre...

There is currently no accurate calculation procedure for determining the lateral-torsional buckling resistance of trapezoidally corrugated web girders. Therefore, a detailed investigation is performed in the frame of an experimental and numerical research program at the Department of Structural Engineering of the Budapest University of Technology a...

The numerical model-based design is commonly applied to steel structures using advanced numerical models and analysis. These models often contain stress concentration zones, which can cause problems for designers within the evaluation process. There are two basic questions to answer in the design: (i) are these stress concentrations real physical s...

Fixed beam-to-column joints in steel portal frames with bolted connections typically present stiffeners to ensure proper load bearing resistance and stiffness to the joint. Executing the same stiffeners with a reduced height (e.g. partial height web stiffener) allows for cost saving during manufacturing but must be paid off by considering its effec...

There is currently no reliable and simple design method available in international literature for the determination of the patch loading resistance of slender plate girders having multiple longitudinal stiffeners. The current research focuses on the patch loading resistance of girders having multiple longitudinal stiffeners. An advanced numerical m...

Nowadays, significant research activities are running parallel and focusing on the development of equivalent geometric imperfections applicable for GMNI analysis which provides safe-sided and reliable buckling resistance using FEM-based design. The currently available local buckling-type imperfection given in EN1993-1-5, which is widely used by res...

There is no commonly accepted and reliable design method to determine the lateral–torsional buckling (LTB) resistance of steel trapezoidally corrugated web girders. Therefore, the focus of the current paper is on the investigation of this failure mode, detailed evaluation of the structural behavior and determination of the accurate LTB resistance....

The flexural buckling resistance of compressed columns is typically determined using the flexural buckling curves of EN1993‐1‐1. With advances in computing capabilities, it has become possible to obtain the flexural buckling resistance as a result of a geometrically and materially nonlinear analysis (GMNIA) using imperfections. In design practice,...

There is currently no reliable and simple design method available in international literature for the determination of the patch loading resistance of slender plate girders having multiple longitudinal stiffeners. Previous investigations focused mainly on girders having one longitudinal stiffener, which is not the common case for box‐girder bridges...

The construction industry is witnessing an increased utilization of steel elements due to their effectiveness and durability, with the ability to fabricate lightweight sections having high bearing capacity. Welded box‐section is one of those elements that gain more attention as it is easy to fabricate and has limited stability issues. Buckling is c...

Knee joints in steel portal frames with bolted connections typically present stiffeners to ensure proper load bearing resistance. Executing the same stiffeners with a reduced height allows for cost saving but must be paid off by considering its effects in the design verification of the joint. The gap of the partial stiffener has a height of 10% to...

Current standards and specifications do not provide specific design methods to determine the lateral-torsional buckling (LTB) strength of girders with trapezoidally corrugated web. In the international literature there are some previous investigations available focusing on the LTB strength of corrugated web girders. Based on numerical calculations...

Before the recent reconstruction, significant corrosion damages were observed on the deck system of the ~170- year-old Sz´echenyi Chain Bridge. Therefore, an advanced reliability analysis-based study is executed to assess the risk of failure of the structure in its situation until the refurbishment starts. The current paper has the aim to introduce...

Application of concrete-filled steel tubes (CFST) is becoming increasingly prominent in the civil engineering practice. However , the interaction of cross-sectional elements in CFST columns raises a number of questions, which have to be investigated in detail to improve design background and analytical resistance formulae. The aim of the current pa...

Deformations of bottom flanges in the vicinity of bridge bearings, i.e., in bearing areas, due to manufacturing and loading can result in serious problems in service life and damages in bridge superstructures and structural bearings coming from nonuniform stress distribution. The paper focuses on the out-of-flatness measurement of bearing areas usi...

The current paper studies the global and local interaction behaviour of box-section columns using numerical simulations by creating a numerical model and analysing their buckling resistances to pure compression. The developed numerical model uses a combination of global and local imperfections as well as residual stresses, which are the key paramet...

The application of steel trapezoidal corrugated web in steel-concrete composite girders has been widespread in building structures and has also appeared in bridges for a few decades, due to their advantageous mechanical properties. Embedding the trapezoidal web in the concrete slab leads to additional advantages such as omitting the welds of the to...

Longitudinally stiffened plates appear in many structural engineering applications. One of the typical failure modes is induced by the buckling of the stiffeners, therefore enhancing our understanding of buckling behavior is of crucial importance. Recently, buckling resistance of longitudinally stiffened plates with trapezoid stiffeners has been in...

The finite element model-based design of steel structures is getting increasing attention by designers, especially in the case of buckling problems of welded plated structures and by the static check of the interacting stability behaviour. The FEM-based design approach is introduced and standardised in the EN 1993–1-5 Annex C providing the ability...

Determining the plate or the local buckling resistance is highly important in designing steel buildings and bridges. The EN 1993-1-5Annex C provides a FEM-based design approach to calculate the buckling resistance based on numerical design calculations (geometrical and material nonlinear analysis - GMNIA). Within the GMNIA analysis-based stability...

Application of high strength steel (HSS – S420 and higher steel grades) is growing nowadays in the civil engineering praxis due to the numerous advantages compared to the normal strength steel (NSS – S235-S355). The accurate consideration of the flexural buckling resistance of HSS structures is highly important in the design. Higher yield strength...

Im Zuge der Entwicklung der zweiten Generation der Eurocodes hat der Eurocode 3 Teil 1-5 „Plattenförmige Bauteile“ eine letzte Fassung erreicht, die nun für die formale Abstimmung in Europa vorbereitet wird. Der Beitrag stellt dazu die Weiterentwicklung des Teils 1-5 von Eurocode 3 vor und macht dessen Anwender mit den wesentlichen strukturellen un...

The accurate consideration of the local (plate) buckling resistance and the determination of the effective width is highly important in the design of civil engineering structures. The current effective width calculation method provided by the EN 1993-1-5 is mainly developed for I-sections subjected to bending. Several previous studies proved that t...

Resistance calculation of steel bridges with orthotropic plates subjected to combined loading situation (bending moment, shear and transverse forces called as M-V-F interaction) can be challenging for designers due to the interactive stability behavior and combined buckling phenomena. The current EN 1993-1-5 standard provides a design method using...

Buckling resistance of longitudinally stiffened plates subjected to compression is a crucial issue in the design of many steel bridges. The design methodology of the current Eurocode describes the behavior as a combination of column-like and plate-like behavior. Previous studies well explored the plate-like behavior of compressed stiffened plates w...

A tanulmány célja, hogy áttekintse a hidak építésének azon körülményeit, amik a saruknál számítás szerint fellépő várható reakcióerőket jelentősen befolyásolhatják, és nem megfelelő kezelésük esetén a saruk és a felszerkezet károsodásához vezethetnek. A szerzők célja, hogy néhány tipikus kialakítás elemzésével felhívják a probléma jelentőségére a s...

Nowadays, the most commonly applied post weld treatment method improving fatigue strength of welded structures is the High Frequency Mechanical Impact (HFMI) treatment method. However, the treatment process is already well-known and widely used, there are several unanswered questions about its impact on the mechanical properties and fatigue behavio...

The focus of the current paper is the investigation of different local stress calculation methods for fatigue design. To evaluate the accuracy and applicability of the hot-spot and effective notch stress (ENS) fatigue assessment methods an experimental and numerical research program is carried out at the BME Department of Structural Engineering, in...

The objective of this paper is to investigate and compare the fatigue behavior of Normal Strength Steel (NSS) and High Strength Steel (HSS) welded specimens (cruciform and flange gusset joints). Numerous specimens were tested in the framework of the research project. The experimental S-N curves of the test specimens are determined and analyzed by m...

An experimental and numerical research program is executed to investigate the fatigue lifetime increase due to grinding-type post-weld treatment method. Plate edge gusset, longitudinal attachment and T-type joint specimens are investigated using fatigue test results, numerical models and mathematical statistical tools. The favourable impact of grin...

The Széchenyi Chain Bridge is a 170-year-old historical structure located in the downtown of Budapest. The superstructure of the bridge was reconstructed several times in its history and currently the renewal process of the bridge is under consideration. According to the current plans main girders, chain elements and cross-girders will remain the o...

Buckling resistance of longitudinally stiffened orthotropic plates is highly important in the design of steel bridges. The current calculation method of Part 1.5 of Eurocode 3 is based on the concept that the behaviour can be superposed from plate-like and column-like behaviours. Recent results indicate uncertainties in the application of the curre...

Traditionally in steel‐concrete composite bridges, the structural elements with different materials are work together with headed stud shear connectors welded to the top flange of the steel beam. The application of trapezoidal corrugated web embedded in the concrete slab provides an alternative for steel‐concrete composite and hybrid structures, ho...

It is commonly known that compression resistance of longitudinally stiffened orthotropic plates depends on both the column and plate-like behavior. Large number of previous investigations studied the structural behavior of stiffened plates subjected to compression. However, a comprehensive investigation and a parametric study is not available in th...

The most sufficient welding parameters and settings of manufacturing technologies are currently mainly determined by experiments for standardised production in the practice. It is a time-consuming method, while there is a large amount of waste during the 'trial and error' process of distinct welding technologies. Virtual fabrication and virtual tes...

Generally, optimum welding variables and conditions of manufacturing are currently mainly determined by experiments for standardized production. Virtual manufacturing and virtual testing of weldments using finite element method provide a sustainable solution for advanced applications. The aim of the current research work is to develop a weld proces...

Steel I-girders with slender web are commonly used in the engineering practice. Previous research results proved that the current bending and shear interaction (M-V) check of the EN1993-1-5 does not always provide safe side resistance. The current research work focuses on the analysis of the M-V interaction behavior of longitudinally unstiffened an...

Residual stresses and initial geometric imperfections have important effect on the buckling resistance of slender plated steel structures. Despite their large importance, the actual knowledge on residual stresses and exact geometric imperfections are limited, especially for corrugated web girders. In the accompanying paper [1] (Part 1) a finite ele...

Plate buckling resistance calculation of orthotropic plates and the determination of the effective width is highly important in the design of bridges. The current effective width calculation method provided by the EN 1993-1-5 [1] is developed for I-sections subjected to bending. Previous research results proved that the application of the plate buc...

Steel I-girders with corrugated webs have been widely used in the past decades, especially in bridges. Although, there are several specialities in their structural behaviour which needs further investigation. Buckling resistance of slender structures is sensitive to imperfections due to residual stresses and initial geometric imperfections. Shear b...

Current standards and specifications do not provide design methods to determine the lateral-torsional buckling (LTB) strength of girders with trapezoidally corrugated web. In the international literature there is only a limited number of previous investigations available focusing on the LTB strength of corrugated web girders. Based on numerical cal...

Dedicated to Univ.‐Prof. Dr.‐Ing. habil. Frank Werner on his 70th birthday Zusammenarbeit zwischen Weimar und Budapest bei der rechnergestützten Modellierung von Stahl‐ und Verbundkonstruktionen Der Beitrag gibt einen Überblick über die langjährige Zusammenarbeit zwischen der Bauhaus‐Universität Weimar und der Budapester Universität für Technik und...

Steel corrugated web girders are increasingly used in buildings, industrial halls and bridges due to their well-known advantages. Numerous researchers highlighted and studied the advantages and favorable properties of the trapezoidally corrugated web girders in the past. However, there are only a limited number of available design proposals for the...

Bridges with box cross-sections are usually stiffened by the combination of longitudinal and transverse stiffeners. The longitudinal stiffeners are loaded by axial force, and the transverse stiffeners should give sufficient support to them. The design of transverse stiffeners without direct loading can be done by the verification of the minimum sti...

Application of steel I-girders with corrugated webs has been significantly increased in the past decades, especially in bridges. However, there are numerous unknown specialties in their structural behaviour compared to conventional I-girders with flat webs, which needs further investigations. Previously, a large number of test results and numerical...

Hybrid girders with corrugated web are increasingly used in bridge engineering due to its numerous favorable properties. For the web-to-slab connection different layouts have been developed in the past, however, just a few design proposals can be found in the international literature for the determination of the connection’s resistance, especially...

The statistical evaluation of the experimental and numerical results is an essential task in case of resistance model development for civil engineering structures. If a design model is developed which has analytical or empirical background, its safety level has to be confirmed and it should be proved that the developed design method fits the safety...

Steel I-girders with longitudinally stiffened webs are commonly used in the civil engineering praxis, especially in bridges. These structures have usually longitudinal stiffeners on the webs, therefore the determination of the load carrying capacity of girders with longitudinally stiffened webs under the combined loading situation (interaction of b...

According to the previous research results the effect of residual stresses on the high strength steel members (HSS–S500 and higher steel grades) are less severe than for normal strength steel (NSS –steel grades of S235–S460) structures. Residual stresses have a significant influence on the global stability behaviour of steel structures, therefore t...

Previous studies proved that the patch loading resistance model of the EN1993-1-5 can lead to significant underestimation of the patch loading resistance in case of longitudinally stiffened girders. Recently there are several research activities to improve the design method. In the current study experimental research program is executed on 8 large...

The accurate consideration of the flexural buckling resistance of high strength steel (HSS) structures is highly important in the design. Higher yield strength indicates the applicability of smaller cross-sections, which might be more sensitive for stability problems. The purpose of the current study is (1) to investigate the flexural buckling beha...

It is commonly known that the patch loading resistance model of the EN1993-1-5 has a relative large scatter, and it can lead to significant underestimation of the patch loading resistance in case of slender plate girders with longitudinal stiffeners. Large number of previous investigations studied the structural behavior of the stiffened girders su...

The accurate and economical consideration of the flexural buckling resistance of high strength steel (HSS) structures is highly important in the design. According to the previous research results the flexural buckling behaviour of HSS and NSS columns can be significantly different, which differences are not considered in the current design rules. T...

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The exact consideration of the global buckling behaviour of HSS steel structures is very important in the design because due to the higher yield strength smaller cross sections can be used, which might be more sensitive to stability failure. According to the previous research results, the flexural buckling behaviour of HSS and NSS columns can be si...

The 130 years old Eiffel-hall in Budapest is a single-story historical steel building which function was a workshop for locomotives till 2009. The hall with a 95×235 m floor area is built up from 20 truss frames having 5 modules for each. In 2016 the change of the function of the hall was requested, and the workshop and rehearsal centrum of the Hun...

There are contradictional information in the previous studies regarding the relationship between the fatigue strength and the yield strength in case of steel structures. Several previous test result show that the fatigue strength of as-welded specimens do not depend on the yield strength of the base material. However, several studies show that the...

Full scale tests on eight steel‐concrete composite beams have been executed in the Structural Laboratory of the Department of Structural Engineering, Budapest University of Technology and Economics in Hungary. The aim of the test series was to investigate the structural behavior of the new and innovative shear connections applied at the steel‐concr...

The residual stress in steel structural elements has significant influence on the flexural buckling behaviour of compressed members. This phenomenon causes that hot‐rolled, cold‐formed and welded sections with the same geometry have different flexural buckling behaviour and resistance. Previous research results showed that the residual stress patte...

The superstructure of the historical Széchenyi chain bridge in Budapest was reconstructed several times in the history and currently the renewal of the bridge is under design. The independent static check and expertizing tasks of the renewal process were completed by the Budapest University of Technology and Economics Department of Structural Engin...

Girders with trapezoidally corrugated web are widely used structural elements in the civil engineering praxis due to their numerous advantages. However, there is a relatively small number of previous investigations focusing on the determination of the flange buckling resistance of the corrugated web girders. Previous experimental and numerical inve...

Previous research has shown that the residual stresses in high-strength steel (HSS) members can be smaller than those in normal-strength steel structures. To investigate the residual stress distribution in HSS structures, a complex experimental and numerical research programme was carried out on welded square box sections at the Budapest University...

Girders with trapezoidally corrugated web are widely used structural elements in the civil engineering praxis due to their numerous advantages. Despite, there are a relatively small number of previous investigations focusing on the determination of the bending moment resistance and the flange buckling behavior. Previous experimental and numerical i...

Application of the corrugated web girders has been widely spread due to their numerous advantages in the field of bridges and buildings in the civil engineering praxis. This girder type has a special stress distribution and buckling behavior compared to conventional steel I-girders. Despite, there are a relative small number of previous investigati...

Nowadays the barrier of applying HSS (High Strength Steel) material in bridge structures is their low fatigue strength related to yield strength. This paper focuses on the fatigue behaviour of a structural details (a gusset plate connection) made from NSS and HSS material, which is frequently used in bridges in Hungary. An experimental research pro...

Longitudinally unstiffened steel I-girders are commonly used structural elements in the engineering practice. Previous research results proved that the current design method of the EN1993-1-5 EN 1993-1-5 (2005) for M-V interaction check is not always on the safe side for longitudinally stiffened girders, however a systematic review of the M-V inter...

Steel corrugated webs are likely used in the field of bridges in the last few decades due to their numerous advantages. The most favorable layout is the hybrid girder with upper and lower reinforced concrete slabs and with steel corrugated webs. During incremental launching – without concrete flanges – the steel girder can be subjected by the combi...

The application range of the current EN 1993-1-1 [1] for column buckling resistance determination is limited for steel materials up to the steel grade of S460. The EN 1993-1-12 [2] gives design rules for materials up to steel grade of S700. The stability failure of HSS steel structures is very important in the design, because due to the higher yiel...

According to the previous research results the effect of residual stresses on the high strength steel members (HSS) are less severe than for normal strength steel (NSS) structures. Residual stresses have a significant influence on the global stability behaviour of steel structures, therefore the application of the existing buckling curves developed...

The authors had the opportunity to contribute in the erection process of the „Čadečka” highway bridge between September 2014 and June 2015. The tasks of the authors were to design and execute the launching process of the steel main girders together with the design of the launching technology and the static check of the superstructure in each launch...

The new Hárosi Danube bridge on the M0 highway around Budapest has been designed and erected between 2010-2012. The superstructure of the bridge is a continuous steel box girder with 3 spans (3 x 108.5 m). The independent static check in the final stage and during the launching phases are made by the BME Department of Structural Engineering. The cu...

In frame of the tramway network development in Budapest a new tramway line has been established on the south part of Budapest, which crosses the Danube on the Rákóczi-bridge. The bridge superstructure is a continuous double-cell steel box girder having 6 spans with the largest span of 98.52 m. The bridge was originally designed to carry four traffi...

Steel girders with trapezoidally corrugated webs are increasingly used in the field of bridges, especially in case of hybrid and composite bridges. During incremental launching of the bridge the main girders are subjected to bending moment (M) with accompanying shear (V) and transverse forces (F) in the same cross-section, which can result in a cou...

Welding processes belong to the most important and widely used methods creating connections in the steel industry. All the information about a welded specimen's shape and residual stresses are especially important to improve the production quality and to determine the resistance of steel members. The welding process results in microstructural chang...

Girders with corrugated steel web is likely used in bridges as well as in building structures due to its numerous favourable properties. It is known from previous investigations that due to the web corrugation the normal and shear stress distribution in the flange and web plates of the corrugated web girders are different from the stress distributi...

Numerical simulations make the improvement of fabrication process and welding technology. Numerical simulations make the improvement of fabrication process and welding technology possible. Using finite element method the most important information about welded specimens can be determined such as deformed shape, residual stresses or even microstruct...

Both industry and architects are interested in increasingly wide spanned and slender structures, raising the demand in high yield stress resistance of steel structures to save weight and finally costs. Several manufactures are able to provide steel grades even higher than S1100, but the rapid development of the production outpaced the present desig...

During the last decades orthotropic steel decks have become a widely used component of steel bridges, however high numbers of fatigue cracks have been recently detected in these structure types. It is well known, that the orthotropic decks are sensitive to fatigue damage, therefore safe fatigue design is important for the safety assessment of bridg...

Steel girders with corrugated webs are increasingly used in the field of bridges, especially in case of composite bridges. During launching of a bridge structure the girder can be subjected by the combination of bending moment (M), shear (V) and transverse forces (F) which result in a complex stress field in the girder and in an interacting stabili...

Welding processes belong to the most important and widely used methods creating connections in the steel industry. All the information about a welded specimen's shape and residual stresses are especially important in improving the production quality and to determine the resistance of the steel structures. The welding process results in microstructu...

Dieses Kapitel beschreibt die Stabilitatsnachweise nach EN 1993-1-5. Die EN 1993-1-5 stellt unterschiedliche Methoden zur Berücksichtigung des Plattenbeulens zur Verfügung. Die bis hier angeführten Berechnungsmethoden werden theoretisch aufbereitet und die jeweilige Nachweisführung bzw. der jeweilige Rechengang wird anschließend anhand von Beispiel...

During launching of a bridge structure large bending moment, shear and transverse forces can often occur at the same time in the same cross section which can result in governing situations for the design. In case of these structures the interacting stability behaviour should be taken into consideration. Bridge structures have usually longitudinal s...