bluuebunny/crossref_metadata_2025 huggingface dataset:
Modal analysis of a riveted lattice beam for improved retrofitting operations
Authors: Franz Hannah , Chataigner Sylvain , Dieng Lamine , Rinke Mario
Published: September 2023

Wrought‐iron and mild‐steel riveted lattice beams are well‐represented in the metallic construction heritage of 1850‐1930. Many rafters and purlins of roof structures of train sheds or market halls are made of flat and angle bars assembled with single‐riveted joints. During retrofitting operations, those beams are often reinforced to prevent them from buckling. However, the assessment of the buckling risk depends strongly on the modelling assumptions regarding the out‐of‐plane rotational stiffness of the riveted joints. This paper therefore presents an experimental and numerical investigation aiming at quantifying this joint stiffness. A 3m‐long riveted lattice beam, dating from 1930, was collected from a demolition site. An experimental modal analysis was carried out and the measured natural frequencies and mode shapes were used to calibrate a finite‐element model of the beam. A parametric study suggests that the model with clamped connections, i.e. with high out‐of‐plane rotational stiffness, is in better agreement with the experimental results. This result could lead to a less conservative buckling risk assessment and less extensive strengthening measures.
Metal 3D‐Printing for Repair of Steel Structures
Authors: Ghafoori Elyas , Dahaghin Hamid , Diao Chenglei , Pichler Niels , Li Lingzhen , Ding Jialuo , Ganguly Supriyo , Williams Stewart
Published: September 2023

This work employs an innovative technique, wire arc additive manufacturing (WAAM) which is a type of directed energy deposition, for fatigue strengthening of cracked steel components. Different steel plates with a central crack were tested under high‐cycle fatigue loading regime, including a reference plate, a plate repaired by WAAM with as‐deposited profile, and a plate repaired by WAAM and subsequently machined to reduce stress concentration factors. Corresponding finite element simulation was conducted to provide a better understanding on the mechanism of WAAM‐repair. The existing central crack in the reference plate propagated and led to a rupture after 0.94 million cycles, while those in the two WAAM‐repaired plates did not propagate, due to the increased net cross‐section and the compressive stresses induced by the depositing process. However, in the second plate, a new crack initiated at the root of WAAM profile as a result of local stress concentration, and the fatigue life reached 2.2 million cycles (2.3 times as the reference plate). The third plate, on the other hand, survived more than 9 million fatigue cycles with no visible degradation, thanks to its smooth machined profile. The findings of this work indicate that WAAM repair shows great potential as a technique to address fatigue‐related damages in steel structures.
Numerical Modeling of Steel‐Concrete Composite Girders Exposed to Web Shear Buckling
Authors: Numanović Mehmed , Knobloch Markus
Published: September 2023

Assessment of the structural behaviour of steel and steel‐concrete composite plate girders exposed to web shear buckling is essential when it comes to their implementation involving heavy loads and/or long spans. In this paper, numerical model of a benchmark steel‐concrete composite girder capable of capturing this phenomenon has been developed using the ABAQUS software. The developed finite element model, based on a series of large‐scale girders planned to be tested in the future, has been evaluated and elaborated on. That includes the implementation of appropriate analysis procedures, element types and contact behaviour in the study of the post‐critical buckling behaviour of steel and steel‐concrete composite plate girders. The advantages and disadvantages as well as recommendations for the future use of the investigated modelling strategies have been scrutinized. In the end, this study demonstrates the parameters with the most significant influence on the structural behaviour of composite girders exposed to shear loading.
Fatigue tests on connections of hollow sections made of high‐strength steel with shape‐optimized gusset plates
Authors: Winkler Matthias , Dürr André , Herion Stefan , Ladendorf Philipp
Published: September 2023

Structures made of hollow sections are often used in the construction of steel bridges, agricultural machinery and trucks. Due to secondary bending moments and local stress concentrations at the connection between brace and chord these joints have a low fatigue strength. In case of high‐strength steels, a decisive fatigue design leads to larger wall thicknesses and dimensions of the hollow sections and thus to uneconomical constructions. In the course of the research project FOSTA P1442 truss joints of hollow sections made of high‐strength steels were reinforced by attached and plugged through gussets plates to increase the fatigue strength by relocating the most critical detail at the weld toe to areas subjected to lower stresses. At the University of Applied Sciences Munich, 35 large‐scale fatigue tests on hollow section K‐joints with differently shaped gusset plates were performed to verify the results of the Finite Element Analysis. In order to verify the applicability of the results to real structures, two trusses with a span width of 6 meters were tested. Based on the data of the experimental tests, a fatigue design recommendation for connections of hollow sections with gusset plates could be developed. Within this paper the set‐up and results of the fatigue tests are summarized.
Robustness analysis for composite multi‐storey modular buildings subjected to wind loads.
Authors: Swami Gaurav , Thai Huu‐Tai , Liu Xuemei
Published: September 2023

In this research, an attempt has been made to evaluate the structural response of multi‐storey composite modular buildings when subjected to lateral wind loads. Finite element (FE) models were developed in Abaqus for a general 10 storey composite modular building, with and without the consideration of lateral load resisting mechanisms of composite shear walls. Concrete filled steel tubular (CFST) columns and composite shear walls were proposed in place of conventional elements to improve the structural resistance, modularity, and construction timeframe. It was observed that under the effect of wind loads, the forces between the modules are transferred primarily by horizontal axial forces. When the effect of sudden module removal is considered along with the wind, the vertical shear forces in the horizontal inter‐module connection increase and the connection becomes critical in shear. Even though the probability of occurrence of critical wind loads and a sudden module loss is rare, it was concluded that the wind forces do not influence the overall stability of the structure in the event of progressive collapse by sudden module removal if an effective lateral load resisting mechanism has been designed.
The pavilion “Petite Maison” of the European Cultural Capital Esch'22: A case study of circular economy benefits in steel construction
Authors: Sayyareh Shahin , Ummenhofer Thomas , Odenbreit Christoph
Published: September 2023

“Petite Maison” is a collaborative architectural project on the theme of circularity in construction within the Esch2022, European Capital of Culture, in Luxembourg. Focusing on a similar concept, the RFCS project “REDUCE” has previously worked out the structural and environmental analysis of a modularized construction approach to evaluate and highlight the benefits of a reusable, circular steel structure. As a follow up to this project, CoCo Project (Carbon Counting and Projection) currently occupies with the determination of suitable routes to point out low‐carbon emission scenarios for the construction sector considering especially steel and steel composite solutions as well as prefabricated structural elements, which may be in concrete or timber. In other words, the project aims to demonstrate the impact of circular economy objectives in the load bearing building structures, considering majorly columns and flooring solutions containing concrete slabs, Laminated Veneer Lumber (LVL), and steel beams. In this article, the environmental performance of Petite Maison flooring system, as a case study, is investigated in detail. Different scenarios are defined for steel elements to quantify the environmental impacts and to emphasise the benefits of modular and reusable structural components.
Improved Design Rules for Stainless and Carbon Steel Bolts Loaded in Tension and Shear
Authors: Abraham Christoph , Stranghöner Natalie
Published: September 2023

The design of non‐preloaded bolted connections as bearing type connections (category A), tension connections (category D) or bearing type connections subjected to tension and shear loading (categories A + D) is given in EN 1993‐1‐8 for carbon steel bolts. However, the design of these kinds of bolted connections made of stainless steel is given in EN 1993‐1‐4 mainly basing on those regulations developed for carbon steel bolts neglecting the specific material properties of stainless steel bolts. To overcome this lack of knowledge, experimental and numerical investigations as well as reliability analyses were systematically carried out for austenitic and duplex stainless steel bolts on their tension, single‐shear and their interaction resistance. Finally, more economical and harmonised design rules for stainless steel bolts could be developed and implemented in the revision of EN 1993‐1‐4 and the German technical approval abZ/abG Z‐30.3‐6:2022. Subsequently, the regulations covered in EN 1993‐1‐8 for carbon steel bolts were checked, considering already existing experimental results in literature and new test results carried out by the authors regarding the applicability of the newly developed rules for stainless steel bolts. As a result, it was found that the rules for carbon steel bolts can be improved, being in line with the newly developed rules for stainless steel bolts and meeting the Eurocode safety requirements.
Numerical Investigation of a Sustainable Composite Connection
Authors: Tsalkatidis Themistoklis , Rath Lars Christoffer Haug
Published: September 2023

During the last decade there is an increasing awareness towards sustainable construction solutions. The reason of this shift is that the construction sector contributes to approximately 40 % of the global output of CO2 emissions, thus making it essential to act in lowering this high amount. A key aspect in the successful implementation of sustainable construction solutions is the use of construction materials that can be 100% recycled, such as steel, and that come from renewable sources, such as timber. Therefore, the interest in using steel‐timber composite (STC) elements and connections has grown since they can provide a robust alternative construction technique to traditional ones. The aim of this paper is to investigate the structural performance of a bolted STC shear connection using finite element analysis. The connection under study consists of two dahurian larch glulam elements that are bolted to the flanges of an H‐profile steel element by means of four M6 bolts for each timber component. The numerical model has been validated using the results of an experimental study where a pull‐out test of the same connection is performed [1]. Overall, the numerical results have shown good accuracy. The bolt failure has occurred when 47.5 kN of force had been applied. This amount of load is about 12% less than the failure load found in the experiment. The slip of the numerical model has been found equal to 5.4 mm whereas the slip measured in the experiment has been measured equal to 7.5 mm. In addition, the failure mode that has developed in the numerical model is governed by the formation of two hinges on the bolts which coincides to the experimental one. To sum up, the numerical model has managed to capture to a great extent the structural performance of the composite connection as presented in the experimental findings.
Testing of Post‐fire Brittleness for Certain Standard Duplex and Lean Duplex Stainless Steel Grades
Authors: Maslak Mariusz , Pazdanowski Michal , Stankiewicz Marek , Zajdel Paulina
Published: September 2023

The results of post‐fire brittle cracking susceptibility tests conducted on samples made of selected duplex type stainless steel grades exhibiting austenitic‐ferritic structure, in particular on standard duplex X2CrNiMoN22‐5‐3 steel and on lean duplex X2CrMnNiN21‐5‐1 steel, are presented and widely discussed. General conclusions are based on the force‐displacement graphs obtained by the instrumented Charpy impact test. Prior to the test all samples have been subjected to simulated fire action following the steady‐state heating regime and then cooled down to room temperature. Two heating levels have been considered, namely 600°C and 800°C. The first of these levels has been considered as to low, while the second as sufficiently high, to induce in the considered steel structural changes of permanent character. For comparison, two groups of samples have been tested. Samples belonging to the first group have been heated for one hour (simulation of a short fire), while the ones belonging to the second group have been heated for ten hours (simulation of a long fire). In addition, two alternative cooling modes have been considered, i.e. slow cooling in the muffle furnace and rapid cooling in water mist. The toughness tests on samples made of both steel grades have been conducted at two different temperature values, that is at +20°C to simulate the continued service in summer conditions and at ‐20°C to simulate this future service in winter conditions.
Design and Numerical Simulation of a Reusable Steel Column Base Connection with Pinned Energy Dissipators
Authors: Ma Qi , Chan Tak‐Ming
Published: September 2023

This paper presents a reusable steel column base connection in moment resisting frame (MRF), which involves simple yet effective pinned steel plates to dissipate seismic energy and makes full use of the self‐weight of the column to provide re‐centring force. Permanent deformations of dissipative plates may induce non‐negligible lateral drifts of the column. By virtue of the pinned design, additional rotational degrees of freedom are added to mitigate the resistance to the restoring behaviour. Based on the proposed connection, the column can rock back to its original position after earthquake‐generated deformations while remaining within the elastic range. Moreover, the proposed connection can be conveniently installed and replaced to facilitate adaptability and reusability. The mechanical performances of the proposed column base connection under monotonic and cyclic loadings are described by simplified analytical models. A refined three‐dimensional finite element (FE) model is developed. The results of FE modelling help verify the feasibility of the simplified analytical models. Besides, the self‐centring capacity, energy dissipation capacity and low damage behaviour of the proposed connection are then evaluated by the FE models.
Investigation on shear buckling of steel welded I‐section beams with reinforced web openings
Authors: Wang Jian , Li Zheng , Euler Mathias
Published: September 2023

Plate girders with I‐section frequently require large web openings to accommodate ducts and pipes in buildings and bridges. It is known that the critical load equivalent to an unperforated plate can be achieved by an appropriate reinforcement of the web opening. The majority of the investigations on thin‐walled webs with web opening under shear loading has been focused on web slendernesses ranging between 200 to 360. Three tests on plate girders with a web slenderness of 416 are presented that contain web openings. The effect of an all‐around reinforcement (hollow section) of the web opening is studied in three‐point bending tests. The tests are calculated with finite elements accounting for imperfections that had been measured before testing. A parametric study is performed to evaluate different types of reinforcements for high web slendernesses.
Probabilistic design life selection procedure for a steel bridge
Authors: Svechnikov Egor , Snijder H.H. (Bert) , Maljaars Johan , de Boon Johan , Drenth Eize
Published: September 2023

Numerous bridges and viaducts built in Western Europe in the middle of the 20th century are now in service for more than 50 years. Aging and changes in societal demands result in a gradual decline of their technical and functional performance. This consequently forces responsible authorities to replace the obsolete infrastructure in the coming decades.

Large‐scale renovation programs together with further development of the highway network require a lot of resources and make a significant environmental impact. The assumed design life of bridges affects structural solutions and the choice of materials. Therefore, there is an opportunity for more efficient use of resources and reduction of the environmental impact if the design life of new bridges is optimized with respect to life cycle costs and CO2 equivalent emissions.

As multiple design life options exist for any bridge, it is essential to have a consistent approach capable of indicating the favorable option. Therefore, a procedure has been developed for comparison of various design life options based on lifecycle costs and lifecycle CO2 equivalent emissions. The procedure accounts for different traffic growth and traffic load development scenarios and it considers probabilities of these scenarios to happen in the future. This allows to assess the effect of uncertainty in functional parameters resulting in probabilistic lifecycle costs and emissions, which indicate a proper design life option.

The procedure is applied to a large span steel bridge over a river. Two design life alternatives, namely 100 years and 200 years, are considered. This paper summarizes the results of this study and it offers a discussion on limitations and perspectives of the suggested procedure.
Buckling tests on wire arc additively manufactured SHS Columns
Authors: Huang Cheng , Meng Xin , Gardner Leroy
Published: September 2023

An experimental study into the flexural buckling response of wire arc additively manufactured (WAAM) columns is presented in this paper. A total of six square hollow section (SHS) columns were tested under axial compression with pin‐ended boundary conditions. The lengths of the members were varied to achieve a wide range of member slendernesses. Owing to the undulating as‐built profile introduced by WAAM, 3D laser scanning was adopted to capture the geometry and global imperfections of the specimens, while digital image correlation (DIC) was employed to monitor the surface deformation of the specimens during testing. The full load‐deformation histories and key experimental results are presented and discussed. The applicability of the column design provisions set out in EN 1993‐1‐4 to WAAM members is subsequently assessed using the obtained test results.
Innovations for Bolted RHS Column Splices
Authors: Packer Jeffrey
Published: September 2023

Two novel concepts, recently developed in North America, are presented for bolted splices between Rectangular Hollow Section (RHS) column members. Single‐sided bolting through the RHS wall is performed, but using regular high‐strength bolts rather than “blind bolts”. The first concept employs nut‐holding devices, called “Shurikens”, that are pre‐installed on four splice plates fitted to the inside of the two RHS columns. The second innovation is a custom‐designed, hollow, cast steel insert – made of nut‐quality steel – that extends into both the upper and lower columns and has threaded holes to receive the inserted bolts, in lieu of nuts. This “internal plug” is a pre‐engineered solution, tailored to a particular RHS size, and requires no connection design. For both concepts, a bolted shear connection with little protruding steelwork is the result.
Fatigue improvement of rib‐to‐deck welded joints using adhesively bonded steel patches ‐ LEFM‐based parametric study
Authors: Wang Xudong , Leonetti Davide , Miao Changqing , Snijder H.H. (Bert)
Published: September 2023

Rib‐to‐deck welded joints in orthotropic steel decks of bridges are prone to develop fatigue cracks. Repairing such cracks allows for prolonging the life of the infrastructure, provided that structural safety is guaranteed. Among others, the repair technique of adhesively bonded steel patches is relatively simple and inexpensive. Moreover, it has the advantage that the original structure is not altered, e.g. as in the case of crack stop holes. This technique has been used in other details like the diaphragm of steel bridges. However, limited information is available when applied to rib‐to‐deck joints, which are the most common joint type in orthotropic steel decks. This study proposes two repair schemes using adhesively bonded steel patches for the rib‐to‐deck joints. A 3‐D finite element model which takes account of the crack size is established. Based on linear elastic fracture mechanics (LEFM), a parametric study is performed to investigate the effect of patch geometry and adhesive thickness on the performance of repair schemes.
Experimental investigations – Steel rolled I shape beam‐columns with mid‐length restraint
Authors: Gizejowski Marian , Jastrzebski Kamil , Nykiel Damian , Sleczka Lucjan , Wiedro Pawel
Published: September 2023

Steel rolled I shape beam‐columns, especially of narrow flange sections unrestrained between the end supports are sensitive to flexural‐torsional buckling. In order to increase their resistance, in‐span lateral‐torsional restraints are applied. Experimental investigations into the behaviour of steel rolled I‐section beam‐columns under moment gradient are presented in this paper. The beam‐column tested is restrained laterally and torsionally in a mid‐length. The experimental setup and testing procedures are described. A total number of 5 specimens (used for 9 tests with different proportions between the dimensionless maximum bending moment and compressive force) were designed. Test measurements and observations are reported. Finally, the experimental resistance results are compared with those of the preliminary finite element model made available in ABAQUS.
Equivalent global sway imperfections for use in design by GMNIA
Authors: Chan Hou Un , Walport Fiona , Gardner Leroy
Published: September 2023

Three types of geometric imperfection need to be considered in the design of structural systems: global frame out‐of‐plumbness, also referred to as sway imperfections, member out‐of‐straightness, also known as bow imperfections, and local cross‐section imperfections. For modelling convenience, equivalent geometric imperfections are often employed to account for the combined influence of initial geometric imperfections and residual stresses. For design by geometrically and materially nonlinear analysis with imperfections (GMNIA), amplitudes for equivalent bow imperfections for members are provided in prEN 1993‐1‐14; however, no provisions exist for global sway imperfections. Therefore, equivalent sway imperfections suitable for use in the design of steel structures by GMNIA, expressed by the out‐of‐plumbness Φ0,GMNIA are established herein. Two proposals for calculating Φ0,GMNIA are presented: (1) Φ0,GMNIA = Φ0,geom + α/100 with Φ0,geom representing the amplitude of the pure geometric sway imperfection, and (2) Φ0,GMNIA = α/50. In both proposals, the varying influence of residual stresses from different cross‐section geometries and axes of bending is captured by the imperfection factor α, as defined by the buckling curves in EN 1993‐1‐1 for carbon steel and EN 1993‐1‐4 for stainless steel, respectively.
Miniature specimen tests and fracture model of heat affected zone material
Authors: Liu Xiaofan , Yan Shen , Rasmussen Kim J. R.
Published: September 2023

The paper investigates the mechanical properties of the heat affected zone (HAZ) material near welds and compares the properties to those of the base metal and weld materials. A dedicated experimental set‐up was designed and manufactured to test miniature specimens with a cross‐section width in the range of 1 mm to 2.5 mm and a parallel gauge length of less than 10 mm. To identify the HAZ of the welded connections, a macro‐etching technique was adopted, and the shape and size of the HAZ were measured. Afterwards, miniature specimens were extracted from the base metal, weld and HAZ in both the longitudinal and transverse directions of the weld, and subsequently tested in the specialised experimental set‐up. The miniature specimens not only included the normal rectangular plate‐type specimen, but also the notched round bar and grooved plane strain types of specimens. Hence, the stress‐strain curve and fracture strains under various stress states were obtained from the tests. The validity of the Lode angle Modified Void Growth Model (LMVGM) was investigated using the experimental data, and the fracture loci of the base metal, weld and HAZ in both the longitudinal and transverse directions were identified.
On the Optimal Shape and Placement of Longitudinal Stiffeners in Longitudinally Stiffened Plates
Authors: Reden Ghaith A. Abu , Adany Sandor
Published: September 2023

Longitudinal stiffeners are widely used in plated structures to prevent buckling of the slender plate elements and, therefore, to increase the load bearing capacity of these structures. There has been extensive research in the past regarding the shapes, sizes, and placement of these longitudinal stiffeners, however, there has been little research to make comparison between the different stiffener shapes across different numbers of stiffeners. The presented study compares the use of a single open stiffener, single closed stiffener, as well as the use of two open stiffeners. A numerical parametric study was conducted, considering different stiffener types, rigidities, and aspect ratios of the plates, for the cases of pure bending and compressions. The results of the study confirm that using a single closed stiffener or two open stiffeners is almost always more advantageous than the use of a single open stiffener. Furthermore, the study highlighted that it might be more advantageous to use two open stiffeners instead a single closed one.
Influence of Profiled Faces on the Overall Shear Performance of Strongly Profiled Sandwich Panel with Mineral Wool Core
Authors: Silwal Shekhar , Mela Kristo , Ma Zhongcheng
Published: September 2023

The total shear force induced on a profiled sandwich panel by an external load is distributed between the profiled face and core. Sandwich panel with a discrete core material such as mineral wool consists of multiple transverse lamella joints across the full width of the panel, affecting the overall shear performance of the panel as these joints have negligible resistance to shear. Additionally, in some cases the core material is partially bonded only to the lower flange of the profiled face which increase the concentration of stresses in the bonded area leading to the crushing of the core on the support. This work studies the distribution of shear force in mineral wool core sandwich panels with one profiled face utilizing a shear beam test on a specimen cut from the panel including the profiled part. Based on the results and failure modes obtained, this work investigates the behavior and role of the profiled face on the shear resistance of profiled sandwich panels. The distributed shear force between the core and profiled part obtained from the shear beam tests are compared with full‐scale tests suggested by the European Standard EN 14509:2013, thus, exploring the applicability of the devised shear beam test method for assessing the shear properties of profiled sandwich panel.
Fatigue performance of preloaded bolted connection with oversized holes
Authors: Christoforidou Angeliki , Baskar Abishek , Barelts Eric , Kavoura Florentia , Pavlovic Marko
Published: September 2023

Moving towards a more sustainable and circular infrastructure has increased the demand for demountable connectors in hybrid structures combining steel, concrete, and nowadays FRP composite components. Large, prefabricated components need to be transported to the construction site and assembled by means of bolted connections for easy reuse of the components. Slip‐resistant connections are required for such hybrid structures in bridges, which are usually provided by injection or preloaded bolts. The former satisfies the need for large tolerances during execution. However, the behavior of such injection bolts depends on the environmental conditions and the resin complicates the installation and demountability. The current practice of preloaded bolts uses standard hole clearances that do not provide sufficient tolerance for the assembly of large structural components made of different materials and many connectors. This paper focuses on the fatigue performance of preloaded bolted connections with excessively oversized holes that could provide sufficient tolerance for execution. Double lap bolted joints for two different bolt‐hole diameters, regular and 60 mm oversized, are tested under cyclic loading and the increase in slip displacement during the load cycles is compared. The static performance is numerically obtained in terms of residual stiffness, slip and ultimate resistance. It was found the stiffness variation between normal holes and significantly oversized holes is insignificant.
The FAILNOMORE project – Practice‐oriented design recommendations against progressive collapse in steel and steel‐concrete buildings
Authors: Demonceau Jean‐François , Golea Tudor , Elghazouli Ahmed , Santiago Aldina , Dinu Florea , Baldassino Nadia , Kuhlmann Ulrike , Obiala Renata , Weynand Klaus
Published: September 2023

Structural robustness is a specific safety consideration which is currently addressed in modern codes and standards, including the Eurocodes. It requires particular care from all professionals involved in the construction industry. The need for practical guidelines to mitigate the risk of progressive collapse has been emphasised by recent catastrophic events such as the 9/11 terrorist attack in New‐York. The lack of consistent design rules for practitioners is however clearly identified in existing normative documents and literature. Accordingly, various research projects were launched, particularly in Europe through RFCS research projects. Thanks to these research activities, significant scientific background has been developed, with the aim of understanding and characterising the behaviour of steel and composite structures subjected to exceptional events such as impact, explosion, or loss of a bearing member. Nevertheless, there was a need to consolidate the available scientific knowledge and to transform it into a consistent set of practical recommendations in order to facilitate the design of steel and composite structures for robustness. This was the purpose of a recent RFCS project “FAILNOMORE” (grant No 899371) which was concluded in June 2022. A brief summary and discussion of the main outcomes of this project are provided in the present paper.
Estimation of maximum admissible precambering of steel beams
Authors: Matos Rui , Candeias Miguel , Craveiro Hélder
Published: September 2023

Precambering of steel beams is a common process in construction to induce cold or heat deformation (parabola) to compensate for the deflections due to permanent dead loads and a fraction of a live load. However, the maximum allowable cambering (and consequently the minimum radius of curvature) before buckling of the element is not simple to be defined as it is dependent on the straightness of the beam and on the adopted cambering procedure. The main objective of this study is to describe and validate a numerical procedure (validated with experimental tests of beams with and without holes in the web) to properly assess the maximum load allowable. This numerical analysis was conducted including non‐linear material and geometrical imperfections (GMNIA). The effect of the magnitude of the imperfections as well as the impact of the distance between consecutive load application points have been considered and discussed.
Strain‐hardening dependent cross‐sectional slenderness limits for the elastic resistance of steel beams
Authors: Studer Patrick , Taras Andreas
Published: September 2023

It is important that cross‐sections are correctly classified, as this determines their utilisation. The focus of this paper lies on the analysis of the transition point between cross‐sectional classes 3 and 4 for I‐shaped and hollow cross‐sections. In particular, it studies how various degrees of strain hardening and ratios between ultimate and yield strength influence this transition point, which defines whether the elastic moment resistance of a section can be exploited. Numerical simulations with geometrically and materially nonlinear analysis with imperfections (GMNIA) were carried out. The results of the numerical simulations were analysed and consequently, limit slenderness values could be determined and correlations to the hardening behaviour could be found and integrated into corresponding formulas.
Cellular beams and prEN 1993‐1‐13: an opportunity to address environmental challenges
Authors: Glorieux Antoine , Hanus François
Published: September 2023

In recent years, construction has faced new challenges, especially related to the reduction of environmental footprint. Measurement of construction performance in this domain is mainly done through Life Cycle Assessment (LCA).

Steel and composite beams are affecting the height and the weight of buildings and one very effective solution is cellular beam. This attractive solution is not fully integrated in the current design standard. This paper presents how the second generation of Eurocodes; EN1993 and EN1994 will be adapted to enable structural engineers to design cellular beams. A technical description of the specific failure modes and concepts for design are presented in more details. A comprehensive case study developed in agreement with the future parts of Eurocode along with a comparison of different structural solutions for a typical building is shown. Typical composite designs are compared to solutions made of cellular beams.

A Life Cycle Assessment, shows that up to 35% of CO2 eq. emissions can be saved by choosing the right solution. It is not only the structural solution but also the material that influences the environmental impact. Comparisons include high strength steel vs mild steel, hot‐rolled vs welded beams, and XCarb® ‐ steel made from high levels of recycled steel using 100% renewable electricity in an electric arc furnace versus average steel in Europe.
Modelling of bolted joints in fire using the component‐based finite element method
Authors: Der Batuhan , Wald František , Vild Martin
Published: September 2023

This paper presents a study using the component‐based finite element method to analyze the behavior bolted joints in fire. The model was verified and validated on analytical and experimental results at elevated temperature. In this work, the plates are modelled using shell elements and the bolt is represented by non‐linear springs. The elements are analyzed by geometrically and materially nonlinear analysis with imperfections (GMNIA). Consequently, the method used in this work can give reasonable results to predict the behavior of joints at elevated temperature. It is predicting the resistance and the stiffness for design of steel structure at elevated temperature by 3D model with members represented by 1D or 2D elements.
Towards a practicable GMNIA procedure in the footsteps of the Direct Design Method
Authors: Jaamala Lauri , Mela Kristo
Published: September 2023

Eurocode 3 permits to utilize nonlinear finite element analysis (NFEA) in design process by carrying out Geometrically and Materially Nonlinear Analysis with Imperfections (GMNIA). Design by GMNIA can consider material plasticity and redistribution of forces in a system level such that it can result in an economical design regarding the material consumption. Unfortunately, GMNIA is scarcely adopted among structural engineers, most likely due to the complexity of the method. The determination of the safety factor for GMNIA requires numerical or experimental test results which may not be available for the designed structural system. Recently, a more holistic approach, Direct Design Method (DDM), has been introduced. In DDM, structural systems are prequalified by determining the system safety factor in advance based on system level reliability studies, thus simplifying the design process for a structural engineer. This study develops a Eurocode‐compliant DDM, i.e. practicable GMNIA, for Warren roof trusses. The paper presents the prequalification process based on three trusses made of cold‐formed hollow sections of the steel grade S700. Additionally, modelling techniques are presented for cold‐formed hollow sections such that an accurate nominal NFEA model is achieved.
Robustness evaluation and design of steel and steel‐concrete buildings according to current standards and recent research results
Authors: Candeias Miguel , Obiala Renata , Demonceau Jean‐François , Dinu Florea , Marginean Ioan , Weynand Klaus
Published: September 2023

In terms of mitigation of progressive collapse, structural robustness is a specific safety consideration, which requires particular attention from all professionals involved in the construction industry, including architects, designers and constructors. The design of buildings considering robustness has evolved considerably over the last two decades, during which different research activities have been developed, leading to new methods and design processes. These practice‐oriented methods and concepts have been recently summarized in a design manual prepared in the framework of the FAILNOMORE RFCS project (grant No 899371), providing to the designer a general design strategy for robustness based on these methods as well as easy to follow worked examples. The proposed design strategy allows to ensure the global stability and the mitigation of progressive collapse of steel and composite structures when subjected to exceptional events, such as vehicle impact, explosion, cascading events involving localized fire or events which are not explicitly specified in the typical structural design process. In this paper, the application of these recommendations is demonstrated by means of realistic worked examples. Typical steel and steel‐concrete composite office buildings, designed according to the current European standards, are evaluated for robustness against identified and unidentified threats. The results obtained with simple and more advanced verification approaches are compared, and possible solutions to improve the robustness of the structures are provided.
Web Bearing Test of Cold‐Formed Austenitic Stainless‐Steel Channels Under Interior Loading
Authors: Yousefi Amir M. , Samali Bijan , Yu Yang
Published: September 2023

Ductility, durability and high corrosion resistance of stainless steels make them appealing to use in construction industry. When used as structural sections, they are, however, subjected to localised failure in the web. This study aims to examine the structural behaviour of cold‐formed austenitic stainless steel channels under localised interior bearing loads. The results of 21 tests on unlipped channels with different cross section sizes and thicknesses are presented. Nonlinear quasi‐static Finite Element (FE) model is then developed. The FE model is validated against experimental test results and demonstrated good agreement in terms of bearing strength and failure modes. In addition, the experimental and FE results are used to compare the results against the results predicted in accordance with the American specification SEI/ASCE 8:2002 and European Standard EN 1993‐1‐4:2006. It is found that the current design equations are unreliable and too unconservative to use for cold‐formed austenitic stainless steel unlipped channels, especially when compared to SEI/ASCE 8:2002, as much as 41%.
Flexural resistance of 3D cut welded joints between SHS columns and through I‐beams
Authors: Sato Atsushi , Latour Massimo , de la Peña Amparo , Benedetto Sabatino Di , Francavilla Antonella Bianca , Rizzano Gianvittorio
Published: September 2023

Steel structures can be designed according to different framing methods depending on the location of Moment‐Resisting‐Frames (MRFs). In Europe and the United States, one‐way MRFs are widely exploited due to their ability to clearly identify the seismic and gravity frames and limit the use of expensive joints only in MRFs. Furthermore, this is the most appropriate solution if double‐tee columns are adopted since they can provide high strength and stiffness only in the plane orthogonal to their strong axis. Instead, two‐way MRFs are commonly used in Japan; this solution creates 3D seismic structures and requires the selection of columns able to provide enough strength and stiffness along both their axes. This is the reason why tubular columns are usually used in Japan. Nevertheless, the main drawback of this practice is the need to manufacture complex beam‐to‐column connections.

In this framework, the recent introduction of 3D Laser Cutting Technology (3D‐LCT) in Civil Engineering provides a way to reduce this complexity. It allows manufacturing quickly 3D cutting shapes with high precision, optimising the welding quantity and costs. Moreover, all the operations are programmed and fully realised by the machine, avoiding any intervention of operators, eliminating human errors, increasing the quality level and saving time. An example of this simplification is given by connections between Square‐Hollow‐Section columns and passing‐through double‐tee beams. Nevertheless, the novelty of this solution represents a limit to its application in practice because no design equations are currently included in common standards.

To fill this knowledge gap, this paper investigates the flexural behaviour of SHS columns to passing‐through double‐tee beam connections according to the component method approach. In particular, the study has been carried out through numerical and analytical activities devoted to providing design formulations.
Insights into the occurrence of transverse bending stresses in web plates of crane runway girders
Authors: Zauchner Paul , Kettler Markus , Unterweger Harald
Published: September 2023

Crane runway girders are installed in industrial buildings to carry heavy loads from crane operation. The wheels of the bridge crane introduce concentrated forces in the crane runway girder via the rails. This leads to local vertical stresses in the web plates of the crane runway girders in addition to the global bending stresses. The local stresses at the top of the web usually become crucial for the fatigue design of the girder. The potential eccentricity of vertical wheel loads as well as additional horizontal forces from operation of the crane can lead to torsional rotations of the rail and the top flange and subsequently to transverse bending of the web plate of the crane runway girder. In the current design model of EN 1993‐6, the rotation at the top of the web plate is described by assuming the rail and the top flange of the girder acting as a bar under torsion, supported continuously by the bending stiffness of the web. Within this paper the existing model for the rotations is improved and it is shown that these modifications lead to more accuracy in comparison with numerical finite element calculations. It is also shown that the current simplified procedure for calculating the resulting stresses in the web is not able to adequately describe the real stresses for all practical cases. It is found that the quality of the stress predictions can significantly be improved by considering the web as a simply supported plate with the previously identified rotations on its top edge.
Seismic assessment of the steel Moment Resisting Frame equipped with friction beam‐to‐column joints
Authors: Poursadrollah Arash , D'Aniello Mario , Tartaglia Roberto , Landolfo Raffaele
Published: September 2023

Supplementary dissipative devices are viable solutions to enhance the seismic response of building structures. In particular, friction devices are low‐cost and easy‐to‐maintain systems that can be easily inserted into moment‐resisting beam‐to‐column joints of steel Moment Resisting Frames. The effectiveness of dissipative friction joints has been widely demonstrated in many research project. In Europe, the first building equipped with such devices will be fabricated in Italy within the framework of the ongoing RFCS DREAMERS project. The preliminary seismic assessment of this prototype building using the framework of performance‐based earthquake engineering method at different performance levels is summarized in the present paper. To this end, nonlinear dynamic analyses are carried out on three‐dimensional (3‐D) models of the prototype developed in “OpenSees”. The results show that this type of structure can be free of damage under earthquakes corresponding to significant damage and near collapse limit states.
Creation of design models of silos for grain storage under conditions of non‐axisymmetric actions
Authors: Makhinko Anton , Makhinko Nataliia , Semko Volodymyr
Published: September 2023

The article describes the authors' experience creating silos for grain storage models in programs for finite element analysis of building structures. Particular attention is paid to the thin‐walled structures of the silo's vertical walls, considered an orthotropic shell of revolution. The shell is orthotropic because the silo walls are made of sinusoidal corrugated sheets and reinforced with vertical stiffeners. The direct calculation of such shells in finite element analysis programs is associated with great computational difficulties (especially in problems of geometrically nonlinear analysis). Therefore, an alternative method is proposed for creating design models of silos, which allows, without loss of analysis accuracy, to significantly reduce the dimension of models and analysis time, thereby increasing the efficiency of structural analysis. The method is helpful for the analysis silos for non‐axisymmetric loads associated with a moment stress‐strain state in the silo walls. Non‐axisymmetric actions are loads from the filling and discharge of the silos, wind effects and loads from blast waves.
Out of the box strengthening design of steel box girder for an existing tied‐arch bridge
Authors: de Meijier Felix , Tjepkema Daan , van Es Sjors , van Dooren Frank
Published: September 2023

The renovation of the 2nd Van Brienenoord Bridge, planned in 2026‐2029, requires strengthening of the complete arch. Four thick steel strips were added on the web plates and assumed as stiffeners in the reduced cross‐sectional method. Investigation was done to verify if this is correct, as the new prEN1993‐1‐5 draft version classifies the strengthening strips as so called ‘weak’ longitudinal stiffeners.

A FE model of an arch segment was made to undertake a geometrically and materially nonlinear analysis with imperfections included, also referred to as a ‘GMNIA’. The arch segment was loaded incrementally by applied displacements until the limit strain of the steel on a fiber, or the maximum reaction force, was reached. The results were compared against the EN1993‐1‐5 methodology. Considering realistic ULS load cases, the GMNIA showed that the sections have about 9% more capacity. This confirmed the assumptions and strengthening design for the arch.