bluuebunny/crossref_metadata_2025 huggingface dataset:
The influence of the steel beam‐concrete slab interaction on the robustness capacity of steel frames
Authors: Jakab Dominiq , Dinu Florea , Neagu Calin , Dubina Dan
Published: September 2023

Seismic resistant multistorey steel frames are expected to mitigate progressive collapse even when subjected to extreme loading events. The use of high redundant structural systems and ductile members and connections are key features that provide such structural robustness. The composite action between the steel beam and the concrete slab may also help increasing the robustness, but in practice it is difficult to quantify this contribution if the joint behaviour is not detailed. The paper presents the results of a numerical study that aimed to investigate the contribution of the composite action to the progressive collapse resistance of steel frame structures. The main parameters investigated in the study were the level of the composite action in beams and strength and stiffness properties of beam‐to‐column joints. The numerical model was calibrated using two reference experimental column loss tests, one with steel beams and one with composite beams. The model considers the interaction between the steel beams and concrete slab by means of shear studs and reinforcement detailing. The results showed that the contribution of the slab lessens the demands on the joints when compared with bare steel systems and provides and adequate behaviour at large deformation stage. The progressive collapse resistance may be further controlled by means of joint flexural and axial strengths.
Design to manufacture of fully stressed curved structures through elastic deformation of thin steel sheets with interlocking connections
Authors: Moussavi Seyed Mobin , Lienhard Julian , Liu Dongyuan
Published: September 2023

The research project presents the development of a fully digital design to manufacture process chain for high‐performance curved steel elements produced by laser cutting thin steel sheets and assembled through elastic deformation. Although there have been developments in industrial robotic setups to automate steel beam bending, these processes rely on an iterative approach and are time‐consuming and costly when there is a need for high accuracy.

The paper shows how the production of tailor‐made geometric parts with interlocking connections enables the design of free‐form structure as well as the complete integration of secondary functions such as façade and mounting positions. The research is based on an integrated co‐development of the construction system, structural FEA analysis, as well as manufacturing and assembly methods. A computational tool was developed to combine geometric studies and structural analysis and to automate fabrication data. This project is situated in an industrial context to test the potential for upscaling the system and detailing techniques for the assembly of curved geometries. The potential of the system is demonstrated through the design and fabrication of a 1:1 scale canopy.
Applications of 3D scanning and digital image correlation in structural experiments
Authors: Meng Xin , Pullen Andy , Guo Xi , Yun Xiang , Gardner Leroy
Published: September 2023

The primary aim of the present study is to explore the use, advantages and potential of two advanced data acquisition techniques – 3D scanning and digital image correlation (DIC), in the testing of metallic structures. 3D scanning is a novel method for capturing the full outer geometry of an object. It is being increasingly used in experimental studies for the determination of dimensional parameters and the characterisation of local and global imperfections, examples of which are given and discussed. Digital image correlation (DIC) is a rapidly evolving technology for the full‐field measurement of the displacements and strains over a surface. A brief introduction to DIC and its workflow is firstly provided. Example applications of DIC in various scales of experiments, including material tests, structural element tests and full‐scale structural system tests, are subsequently discussed. These new‐generation data acquisition techniques enable structural researchers to gain a deeper insight into the behaviour of metallic structures in experimental research.
Novel method for the prediction of load bearing capacity of compressed C channels considering interaction of buckling modes
Authors: Vaszilievits‐Sömjén Bálint , Papp Ferenc
Published: September 2023

The proposed method focuses on the interaction of global and local buckling. A modified Ayrton‐Perry type buckling curve is proposed to calculate the ultimate compression force resistance of centrically compressed cold‐formed C channel. The new buckling curve incorporates both the effects of global imperfections and shift of the center of gravity caused by local buckling of slender web plate of the considered sections. Distortional buckling usually does not play any role for this configuration.

The effective cross‐section properties for the use of the new buckling curve are determined using critical stresses obtained both by finite‐elements analysis and finite strip analysis. The shift of center of effective cross‐section will produce an additional second order bending moment amplified with the corresponding global buckling multiplier.

The results are compared with the curve proposed by AISI Direct Strength Method for global‐local interaction and with simulation results, in agreement with the recommendations of the new prEN 1993‐1‐14.
Finite Element Analysis on Flexural Bearing Performance of Innovative Closed Profiled Steel Sheeting‐Concrete Composite Slab
Authors: Ding Lu , Yongjiu Shi , Dong Liu
Published: September 2023

Based on ABAQUS system, the flexural behavior of the closed profiled steel sheeting‐concrete composite slab was studied. The influence of different geometric and material parameters on the bending bearing capacity and flexural rigidity of the closed profiled steel sheeting‐concrete composite slab was analyzed. And the applicability of the current Chinese codes to the calculation of the bending bearing capacity of the closed composite slab was discussed. The results showed that, the influence of slab thickness is the largest, followed by the thickness and strength of steel sheeting, and the influence of concrete strength is the smallest; the calculation of the flexural bearing capacity of the closed profiled steel sheeting‐concrete composite slab is safe and conservative in accordance with the current Chinese codes.
Experimental investigations on the load‐bearing behavior of shear studs in trapezoidal sheet in fire
Authors: Tutzer Kurt , Kaul Mathias , Mensinger Martin
Published: September 2023

Composite slabs, consisting of a steel section, profiled sheet and concrete, have been used successfully in composite construction for many years. In order to increase the maximum span widths, trapezoidal sheets with deeper ribs are increasingly being used. The use of modern deep steel decking changes the load‐bearing behaviour of the shear studs towards greater flexibility and ductility, but also towards a lower load‐bearing capacity. In recent years, a significant amount of research has been carried out into the load bearing behaviour of shear studs in profiled sheets, resulting in the development of a new design approach in the draft prEN 1994‐1‐1. Compared to the Ultimate Limite State (ULS), scarce research has been conducted for elevated temperature. It is therefore difficult to evaluate the compatibility of the new design approach from the draft with the existing regulations from EN 1994‐1‐2. In order to fill this gap in knowledge, push‐out tests have been carried out on trapezoidal sheets under elevated temperature. The focus of this paper is to describe the experimental approach and the first results.
Analytical and numerical calculation of the buckling stress for panels with closed‐section stiffeners
Authors: Piculin Sara , Pourostad Vahid , Može Primož , Kuhlmann Ulrike
Published: September 2023

The forthcoming second generation of EN 1993‐1‐5 is bringing changes in terms of buckling and interpolation curves that allow the positive effects of torsional stiffness of closed‐section stiffeners to be taken into account. Regarding the determination of the critical buckling stress for global plate buckling, analytical or numerical methods may be used. FprEN 1993‐1‐5 provides a simplified analytical equation for determining the critical buckling stress of an equivalent orthotropic plate, which can also be found in the informative Annex A of EN 1993‐1‐5. The given equation does not take into account the torsional stiffness of longitudinal stiffeners with closed cross‐sections. The latter are often used in plated structures due to fabrication and strength benefits. This paper compares two methods for determining the elastic critical plate buckling stress that consider the positive effect of the torsional stiffness of closed‐section stiffeners. First, a newly proposed analytical method that accounts for the torsional stiffness of closed‐section stiffeners is derived on the same basis as the current equation in Annex A. Secondly, a numerical linear buckling analysis is performed on a large number of stiffened panels. The advantages and disadvantages of both methods are pointed out. Finally, both values are used to determine the ultimate resistance of plates and with GMNIA results from previous studies.
Study of the Behaviour of S355 Welded Joints with CHS Columns and Through Beams
Authors: Safaeifaegh Shervin , Zanon Gabriele , Bursi Oreste S.
Published: September 2023

Circular hollow section elements are an appealing solution in steel structures, but the complexity in the realization of the joints represents their main limitation, particularly in the case of columns with passing through beams. In this context laser cutting technology allows for simplified solutions. The minimal clearances between the elements and bevels to achieve full/partial penetration butt welds are important aspects to optimize the behaviour of joints subjected to seismic and gravitational loads. The RFCS LASTTS project was conceived and funded to investigate the performance and to optimize the fabrication of the joints. In this context, numerical analyses based on the FE method by means of the ABAQUS software and an experimental tensile tests campaign on the joints were carried out. Three different welding solutions of joints, full penetration butt weld and full/partial fillet weld, made using mild steel S355 are studied. The study provides important indications on the choice of the most suitable weld techniques for the studied joints highlighting a good behaviour of the full‐strength fillet weld solution. Moreover, the good agreement between experimental and numerical results highlights the capability of the model to investigate joint with different geometries.
Study of the effects of laser cutting processes on S235 structural steel
Authors: Shamlooei Majid , Zanon Gabriele , Brugnolli Marco , Bursi Oreste S.
Published: September 2023

Laser cutting technology shows advantages in advanced industrial manufacturing processes due to high machining speed and precision to cut complex geometries. Nonetheless, its thermal process is characterized by complex physical mechanisms that alter material properties and the structural response of the cut element subjected to high fatigue loadings. The optimization of laser cutting parameters by cut attempts and the evaluation of the mechanical response by testing is very expensive. A 3D numerical model based on the FE method was developed to investigate the thermal effects due to the laser cutting process on mild steel S235. Due to the complexity of the process, monitored cutting processes and material tests were carried out to calibrate and validate the FE model. More precisely, temperature profiles were observed by thermal camera and thermocouples on specimens cut using different laser cutting parameters. Besides, microstructural observations on the heat affected zone were performed using microscopy and XRD methods. The proposed model was capable to simulate the laser cutting process and its results were in good agreement with the corresponding experiments in terms of temperature distribution, temperature history, and micro‐structures inside the cut specimen.
Novel bolted steel joint to improve anti‐collapse resistance of steel structure
Authors: Kozlowski Aleksander , Kukla Damian
Published: September 2023

As a joints play a significant role in load transfer both in persistent and accidental situation an attempt to improve structural robustness under column loss situation was made. Based on previously conducted experimental tests of bolted double side steel end‐plate joints and numerical analysis a development to increase load‐capacity and rotational capacity of joints under column loss scenario was presented. Finite element method using Abaqus software with 3D numerical models were employed. Validated and complex models with geometrical and material non‐linearity with fracture simulation were applied. The application of additional double rings to bolted steel flush end‐plate joint lead to significant increase of load‐capacity and rotational‐capacity. The change of failure mode of joint were also obtained compared to the original specimen.
Remote monitoring system for an onshore steel wind turbine
Authors: Simoncelli Marco , Zucca Marco , Ghilardi Matteo
Published: September 2023

The paper presents a monitoring system applied to an existing steel tubular wind tower located in Italy, having almost 45 meters of total height. The monitoring system was comprised by strain‐gauges and thermal couples, mounted on the tower shell at 21 meters of height, and few accelerometers, located along the tower's height. The monitor system was used for two main reasons: i) to understand the nature of the resonance problem experienced by the tower and ii) to evaluate the effective stresses distribution on the shell with different rotor velocities. Finally, a debate about the extension of the life of the wind tower is proposed.
Design assisted by finite element analysis – Introduction to prEN 1993‐1‐14 and Technical Report
Authors: Dunai László , Kövesdi Balázs , Gardner Leroy , Al‐Emrani Mohammad , Casafont Miquel , Degée Herve , Jandera Michal , Kuhlmann Ulrike , Taras Andreas , Walport Fiona
Published: September 2023

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 extension where necessary to cover all fields of structural steel design. Within the development process, two documents are being prepared: (i) the code, prEN 1993‐1‐14 and (ii) a Technical Report. The new code aims to provide rules on the use of finite element analysis and other numerical methods for verifying ultimate limit states, serviceability limit states and fatigue. In parallel, the Technical Report will provide background information and explanations of all aspects of the code, as well as benchmark cases and design examples to support the correct application of the prEN1993‐1‐14 design rules and the necessary benchmarking required for model validation. The assumed stakeholders are mainly designers who can find direct guidance for design by finite element analysis in daily engineering practice. This current paper gives an overview of the new code and accompanying Technical Report, as well as the development process and harmonisation within the current Eurocode 3 framework.
Comparative study of different steel‐concrete composite shear walls
Authors: Anwaar Omer , Pepe Davide , Zanon Riccardo
Published: September 2023

High‐rise buildings are typically subjected to horizontal loads as wind and earthquake, therefore, to provide an adequate lateral stiffness and resistance, structural cores should be considered within the structure.

For this reason, to provide alternative yet advantageous solutions, a comparison between concrete cores and composite cores for high‐rise buildings' performances is presented here. Some recent applications in US and China, indeed, showed how the steel‐concrete composite shear wall solution could give better results in terms of construction time and constructability ensuring a significant financial gain.

Different ideas of composite shear walls will be presented and parameters of stiffness and resistance for each cross section will be evaluated. Thereafter, the best solutions, in terms of the abovementioned parameters and constructability, will be implemented into a real case of a building, modelled on ETABS software and compared with the original solution in reinforced concrete. In addition to highlighting the structural benefits of the proposed solution, it will be shown that the proposed solution has lower carbon footprint compared to other conventional solutions.
Comparison of seven ductile fracture initiation prediction models for stainless steel
Authors: Nambirajan Tamilselvan , Ghosh Diptarka , Kumar P C Ashwin
Published: September 2023

Seven axisymmetric notched specimens extracted from stainless steel of yield strength 450MPa are tested under monotonic loading. The numerical simulation of all seven specimens is modeled in ABAQUS CAE, and the inbuilt constitutive model is used to capture the isotropic hardening behavior. The hardening parameters are calibrated until the numerical model simulates the exact behavior of load versus elongation obtained through experiments. The calibrated numerical model is used to determine the three fracture‐predicting parameters, namely stress triaxiality (T), equivalent plastic strain (PEEQ), and Lode angle (L). These three parameters are required in developing the fracture locus of 450 MPa Indian stainless steel. In addition, the study employs seven existing fracture prediction models for fracture initiation in all seven study samples. Using the determined values of T, PEEQ, and L at the fracture initiation point from the calibrated numerical simulation, the co‐efficient of all the seven selected models is calibrated. With the mean calibrated co‐efficient of all the specimens, the balanced error for all the models is calculated. With the help of the calculated balanced error, the efficiency of all the selected models in predicting the fracture initiation point is compared. Finally, the efficient model for 450 MPa Indian stainless steel is identified in this study.
Predictive modelling and latent space exploration of steel profile overstrength factors using multi‐head autoencoder‐regressors
Authors: Kraus Michael A. , Müller Andreas , Bischof Rafael , Taras Andreas
Published: September 2023

This paper investigates the suitability and interpretability of a data‐driven deep learning algorithm for multi cross sectional overstrength factor prediction. For this purpose, we first compile datasets consisting of experiments from literature on the overstrength factor of circular, rectangular and square hollow sections as well as I‐ and H‐sections. We then propose a novel multi‐head encoder architecture consisting of three input heads (one head per section type represented by respective features), a shared embedding layer as well as a subsequent regression tail for predicting the overstrength factor. By construction, this multi‐head architecture simultaneously allows for (i) the exploration of the nonlinear embedding of different cross‐sectional profiles towards the overstrength factor within the shared layer, and (ii) a forward prediction of the overstrength factor given profile features. Our framework enables for the first time an exploration of cross‐section similarity w.r.t. the overstrength factor across multiple sections and hence provides new domain insights in bearing capacities of steel cross‐sections, a much wider data exploration, since the encoder‐regressor can serve as meta model predictor. We demonstrate the quality of the predictive capabilities of the model and gain new insights of the latent space of different steel sections w.r.t. the overstrength factor. Our proposed method can easily be transferred to other multi‐input problems of Scientific Machine Learning.
Web crippling behaviour of cold‐formed high‐strength steel unlipped channel beams
Authors: Kanthasamy Elilarasi , Alsanat Husam , Poologanathan Keerthan , Perampalam Gatheeshgar , Shanmuganathan Gunalan , Nagaratnam Brabha , Corradi Marco
Published: September 2023

Construction industries have increasingly sought to adopt Cold‐Formed Steel (CFS) sections as primary and secondary load‐carrying members. Also, the evolution of the CFS industry leads to fabrication of high strength CFS sections due to their added benefits such as higher strength‐weight ratio, most appropriate to employ in high‐rise and long‐span applications, and lesser carbon footprint. However, large width‐to‐thickness ratios of these thin‐walled beams make them vulnerable to local buckling failure, a major failure mode being web crippling when subjected to concentrated loads. The design standards predict the web crippling capacity of CFS sections according to the experimental studies conducted in previous years. Innovative concepts like the production of CFS using high‐strength materials should be examined undergoing web crippling. Therefore, the web crippling behaviour of the unlipped channel sections with material strength up to 1000 MPa under all four loading conditions: End‐Two‐Flange (ETF), Interior‐Two‐Flange (ITF), Interior‐One‐Flange (IOF) and End‐One‐Flange (EOF) was investigated in this study. Numerical simulations using Finite Element Analysis (FEA) software (ABAQUS) were conducted on 972 parametric studies following proper validation. New modified equations were proposed to predict the ultimate web crippling capacity of high strength unlipped channel sections and parametric analyses were carried out among various loading conditions.
Optimization methods for the design of advanced 3d‐printed metal seismic dissipation devices
Authors: Andreacola Francesca Romana , Brando Giuseppe
Published: September 2023

In recent years, the topic of passive building protection became increasingly relevant due to the intense seismic activity in many parts of the world, often impacting densely populated areas. In the meantime, modern additive manufacturing technologies enabled the introduction of devices for structural applications that are innovative both in terms of final shape and design methods. The aim of the research project is to develop metal energy dissipation devices (dampers) from conventional geometric shapes and then direct the design towards specific performance in terms of strength, stiffness and dissipative capacity through optimization algorithms, with the aim of optimizing their function when employed as damper for the seismic protection of buildings. The subsequent removal of parts in excess of the real structural needs makes it possible to pursue important goals such as saving material, and reducing weight and costs. The proposed study illustrates the results of the first dampers designed through advanced topological and geometric optimization algorithms, implemented within the Abaqus software. The early models, designed from a spherical shape, are conceived to withstand axial stresses, simulating the load that can be transferred through a diagonal brace during an earthquake.
Tensile behaviour of welded S700 rectangular hollow section X‐joints
Authors: Yan Rui , Bamby Hagar El , Veljkovic Milan
Published: September 2023

High‐strength steels (HSS) have higher strength but lower ductility compared to mild steels. A material factor (Cf) and a 0.8fu restriction on the material design yield strength (fy) are stipulated to reduce the design resistance of welded HSS hollow section joints in the newest version of prEN 1993‐1‐8 (2022), given the low ductility of HSS and a limited number of experiments on welded HSS joints. However, applying the material factor and the yield strength restriction partially eliminates the benefits of using HSS, limiting its competitiveness. Besides, the type of the weld (fillet weld or butt weld), which is not distinguished in the design rules in prEN 1993‐1‐8 (2022), may influence the mechanical behaviour of the joint. Hence, in this paper, a parametric study is carried out based on the validated Gurson‐Tvergaard‐Needleman (GTN) damage model and the validated finite element (FE) model of two X‐joints in literature. The effect of two parameters, the brace width to chord width ratio (β) and the weld dimension, on the tensile behaviour of the welded S700 rectangular hollow section (RHS) X‐joint are evaluated. The FE results are compared to the prEN 1993‐1‐8 prediction, and the necessity of Cf and the 0.8fu yield strength restriction is evaluated.
Experiment‐based statistical distribution of buckling loads of cylindrical shells
Authors: Li Zheng , Pasternak Hartmut , Geißler Karsten
Published: September 2023

A silo structure is usually constructed in the form of a cylindrical steel shell. It has the advantages of being lightweight, having a short construction period, and possessing a large storage space. It has been widely used in many fields of industry. Thin‐walled cylindrical shells often exhibit buckling failure and the experimental buckling load is usually lower than calculation results from classical theory and simulation without geometrical imperfection. Besides, test results with carefully conducted similar specimens still have substantial scatter due to imperfection sensitivity. The nonlinear analysis with FEM can obtain a high‐precision result comparing the experiment if the geometric parameters of the shell are fully known. However, this is almost impossible in practical engineering. The initial geometric imperfections and shell thickness of cylindrical shells are complex and random properties. Theoretically, these geometric imperfections can be described using a random field. This paper presents the experimental investigation of buckling analysis of cylindrical shells under axial compression considering the randomness of geometric imperfections and thickness. A total of 12 cylindrical shell specimens were fabricated and tested. Based on the test results, the optimal statistical distribution is obtained by the maximum entropy fitting method and the obtained results were compared with geometric imperfections based on laser scan measurements.
Influence of the Plate Thickness on Fracture and Impact Toughness of Duplex Stainless Steels
Authors: Afzali Nariman , Jabour Georjina , Stranghöner Natalie , Langenberg Peter
Published: September 2023

In the last two decades, the use of duplex stainless steel (DSS) has increased significantly in structural applications due to their low maintenance costs, excellent corrosion resistance in highly corrosive environments, and high mechanical strength. The production of thicker plates by hot rolling leads to larger grains sizes in the material. Besides this, different plate thicknesses have different cooling rates after hot rolling which influence the intermetallic formation of the material. Both these parameters have an influence on the impact and fracture toughness of steel materials. Nevertheless, for duplex stainless steels, a concept for the choice of steel material to avoid brittle fracture according to EN 1993‐1‐10 does not exist so far. For this reason, an investigation has been started in the frame of the German FOSTA research project (P 1390). Two types of DSS plates, 1.4462 and 1.4162, with varying thicknesses were selected and tests were conducted on base and welded material in order to investigate the influence of the plate thickness on the impact and fracture toughness of the material. Furthermore, the suitability of the Master Curve concept and transition temperature correlation for duplex stainless steels has been examined.
Compressive arch action in beams of steel frames subjected to a column loss
Authors: Golea Tudor , Vermeylen Maxime , Jaspart Jean‐Pierre , Demonceau Jean‐François
Published: September 2023

Steel frames subjected to a column removal typically exhibit a complex load resisting mechanism characterised by three contributions: i) beam yielding mechanism, ii) compressive arch, and iii) catenary action. The development of compressive arch actions in the beams bridging over the lost column has not been yet thoroughly investigated in steel frames, although such effects proved to significantly contribute to the collapse‐resistance of reinforced concrete frames.

This paper aims at shedding light on the compressive arch actions of steel beams in case of column removals accounting for various boundary conditions. Numerical and analytical methods were employed for quantifying the contribution of these effects to the structural robustness of steel frames. A simplified analytical model that allows estimating the magnitude of arching effects in steel beams with various types of end‐connections and horizontal restraints provided by the surrounding structure was introduced. The agreement between numerical and analytical results suggests that the proposed analytical model allows for accurate predictions. This validates the model's use for practical applications and gives promising prospects for its inclusion in consistent analytical methods for predicting the activated alternative load path in steel frames subjected to a column loss scenario.
Improving the behavior of semi‐supported steel plate shear walls using diagonal stiffeners
Authors: Kontoni Denise‐Penelope N. , Ghamari Ali , Omid Mohamad Saeid Poor , Ilia Georgios
Published: September 2023

Although Steel Plate Shear Walls (SPSWs) have revealed worthy performance in past studies, the need for huge columns surrounding the infill plate is accounted as a considerable shortcoming. This problem is created due to transferring the infill plate stress to the columns by post‐bucking. Despite using the semi‐supported SPSW, the problem is solved, however, the stiffness and ultimate strength of the SPSW are reduced. This reduction is due to the formation of incomplete tension field action. Therefore, in this paper, stiffening the semi‐supported SPSW using diagonal stiffeners is proposed and investigated numerically and parametrically. To do so, the effect of the stiffener properties, the thickness of the stiffener (ts), the width of the stiffener (hs), and the hs/ts ratio on the behavior of the system were evaluated. These stiffeners not only improve the behavior of the infill plate but also contribute to load bearing. Results indicated that by using the stiffeners, the ultimate strength, elastic stiffness, and energy dissipation capacity of the semi‐supported SPSW are improved, and with a lower hs/ts ratio, a better performance of the system is obtained.
Towards a stability verification of two‐span members based on experimental and numerical investigations
Authors: Bours Anna‐Lena , Winkler Rebekka , Knobloch Markus
Published: September 2023

State‐of‐the‐art stability design methods of the current and future Eurocode 3 are based on idealized, simply supported members with fork restraints. However, in real‐world structural engineering applications, continuous members or frame structures are more common. The verification of these members often requires complex geometrically nonlinear computations. This paper addresses the extension of simplified methods to structural systems. The basis is laid with experimental, numerical and analytical studies on the stability behavior of two‐span members with doubly symmetric I‐sections in bending, axial compression and torsion. Five‐point bending tests were conducted to analyze the buckling behavior of two‐span members. The experimental results validate a numerical model subsequently used to extend the data basis. A comparison of the numerical load capacities with the results of the simplified method for the buckling resistance according to Annex C.2 of EN 1993‐1‐1:2022 reveals the method's applicability. The sensitivity analysis of the method to various parameters identifies potential for improvement concerning the capture of the influence of bending moments about the weak axis and warping moments, as well as the influence of lateral‐torsional buckling for stocky members.
Web crippling behaviour and design of aluminium SupaCee sections
Authors: Thirunavukkarasu Kajaharan , Alsanat Husam , Poologanathan Keerthan , Shanmuganathan Gunalan , Perampalam Gatheeshgar , Kanthsamy Elilarasi , Muhammad Rahman , Higgins Craig
Published: September 2023

SupaCee sections are addressed as one of the innovative section profiles which was introduced to the Cold‐Formed Steel (CFS) industry in the past decade. Longitudinal stiffeners and return lips are the unique features which ensured the better structural performance in terms of bending and shear for CFS sections. However, web crippling performance of CFS SupaCee section was the critical aspect to employ them in the industry as the concentrated loads could induce web crippling failures. Hence, there is a necessity to address web crippling performance of any innovative profiles to utilize them in appropriate locations. On that note, aluminum sections are now emerging in the industry as load bearing profiles considering their lightweight nature, corrosion resistance, ease of fabrication and high specific strength. Aluminium sections are considered as a replacement for CFS sections for modular constructions where the necessity of light weight is higher considering the transport costs and fabrication costs. However, web crippling performance of aluminum sections has to be analyzed to ensure the utilization in modular constructions. Hence, a superior section among available sections in terms of structural performances, aluminium SupaCee section, was considered for this study. Accordingly, a comprehensive numerical study was conducted considering various parameters such as section depth, thickness, bearing length and yield strength, after the successful validation process of the numerical models with the experimental scenarios of End‐Two‐Flange (ETF) loading condition. Ultimately, the results were compared with key parameters and suggestions and recommendations were stated for the utilization aluminum SupaCee sections in the industry.
Compressive Behaviors of Steel Braces with Different Sectional Shapes
Authors: Shin Dong‐Hyeon , Kim Hyung‐Joon
Published: September 2023

Steel braces are an essential structural element to resist lateral seismic forces and widely utilized in various types of buildings. The primary source of load carrying capacity in steel braced frames is through buckling and yielding of diagonal braces. Hysteretic behaviors of steel braces exhibit unsymmetric properties in tension and compression. Especially, they show significant strength degradation when loaded into the inelastic range in compression. Therefore, the governing failure modes of steel braces shall be global buckling in compression and this phenomenon shall occur prior to brittle limit states such as net section rupture or local buckling of elements. Except for effects of material properties, most of influential parameters is strongly related to the configuration and sectional shape of steel braces. Of them, the objective of this study is to investigate effects of sectional shapes on compressive behaviors of steel braces. Especially, this study focuses on the variation in the plastic hinge rotation and residual deformation of steel braces with representative sectional shapes which are typically applied on the construction field.
Novel formula for the elastic critical moment of beams with corrugated web
Authors: Hajdú Gábor , Papp Ferenc
Published: September 2023

This paper presents a novel analytical expression to determine the elastic lateraltorsional buckling resistance of I‐beams with corrugated web. The corrugated web beams have higher torsional stiffness than the flat web beams; therefore, the self‐weight of the beam can be reduced. The appropriate hand calculation methods to determine the elastic critical moment of corrugated web beams are based on the modification of warping constant of the cross‐section. In this paper, instead of modifying the warping constant the approximate expression is derived from the total potential strain energy of the beam using an energy method. During the solution, the beam is separated into three parts. The flanges are modelled as thin‐walled beams and the corrugated web is modelled as a thin equivalent orthotropic plate with uniform thickness. To assess the accuracy of the proposed analytical formula full shell finite element models were created in Abaqus software. The accuracy of the proposed expression is examined for sinusoidal and trapezoidal corrugation also. The results of the parametric study showed that the derived formula is accurate and applicable for elastic lateral‐torsional buckling analysis of I‐beams with web corrugation.
Seismic Performance Evaluation of Moment Resistance Connection by Load Velocity.
Authors: Seol Younghun , Lee Kiwon , Park Jaehan , Oh Sanghoon
Published: September 2023

The seismic performance of beam‐column connections is typically evaluated using a loading protocol specified by codes such as AISC. This protocol involves applying incremental and repeated loads at a specified speed to reach a target rotation angle, with a low load velocity of about 0.5 mm/s to 1.0 mm/s. However, testing at such a low load velocities may not fully account for brittleness breakdown due to factors such as a reduction in material toughness and a decrease in maximum deformation rate caused by stress concentration in vulnerable areas at high load velocities.

Therefore, it is important to verify the seismic performance of connections, including their plastic deformation ability, under the influence of dynamic loads with high velocities, such as those experienced during an earthquake. We conducted a static and dynamic experiment on welded connections and extended end plate connections to analyze the effect of load velocity on connections behavior.

Our results showed that increasing the load velocity reduced the strength of the connection, its plastic deformation capacity, and energy absorption capacity. These findings confirm that load velocity can significantly affect the seismic performance of connections and suggest that the current loading protocol may not fully capture the connection behavior under dynamic loads.
Proposal for determination of wind action on steel rack supported warehouses during execution
Authors: Henriques José , Marra Antonino Maria , van Vugt Glenn , Bartoli Gianni , Degée Hervé
Published: September 2023

The exponential growth of e‐commerce in the last decade boosts the need of large logistic centers. Steel rack supported warehouses (SRSWs) are one of the most competitive solutions for such infrastructures. The execution phase of SRSWs is challenging, as the stability of the structure has to be ensured throughout the different erection stages. The wind action is here particular important. The density of structural elements and the incompleteness of the SRSWs structure, is a vulnerable condition under wind loads. The determination of wind forces during execution according to the EN 1991‐1‐4 is very limited when dealing with open frame structures, and in particular, with structural systems such as SRSWs. In order to overcome this lack, the wind action on SRSWs during execution has been subject of a recent concluded RFCS research project “STEELWAR”. This paper presents the proposal of a method to determine the wind forces on SRSWs under construction. The method is derived from a series of wind tunnel tests. Subsequently, given the inherent limitation of such experimental program, the extension of the method to a range of practical cases is proposed. Finally, an application to a real case study is used to assess the vulnerability of the SRSWs during the execution.
Changes to the lambda model for fatigue loads on steel railway bridges in Europe
Authors: Maljaars Johan , Verdenius Stefan
Published: September 2023

For the fatigue design of steel railway bridges in Europe, the European standards EN 1991‐2 and EN 1993‐2 provide a factored Load Model '71, called the lambda model. The stress range in the fatigue detail of study should be determined with this model. Engineers can easily verify their structural design for fatigue by comparing this stress range to the fatigue reference strength of the detail.

This paper compares the load effect caused by the lambda model with the load effect of actual trains measured with ‘Weigh In Motion’ systems during 7 years at 81 locations in the rail network of The Netherlands. Locations with heavy loads are selected and their load effects in terms of stress ranges and fatigue damage are determined for various influence lines, including one, two and three span beams with spans ranging between 1 and 150 m. The design (i.e. elastic section modulus) is optimized such that the calculated fatigue damage using the damage accumulation rule of Palmgren Miner equals 1 for a 100 years design life for these locations. This elastic section modulus is compared to the elastic section modulus obtained by designing according to the lambda model.

Improvements are proposed to the lambda model based on this comparison, such that the resulting design gives a reasonable agreement with the design based on measured loads, while maintaining the current ease of use of the lambda model. Uncertainties such as possible changes in axle loads and train speeds in future are taken into account.
Non‐Destructive Testing of Bridge Cables using MIT
Authors: Ruff Daniel C. , Eirich Hans
Published: September 2023

This article presents the importance of non‐destructive testing (NDT) in maintaining the safety and functionality of bridge cables, and focuses on the practical use of magnetic‐inductive testing (MIT) and ultrasonic testing (UT) for NDT of bridge cables in free length and in the area of the end connectors. MIT is a non‐invasive method that can effectively detect defects such as broken wires, corrosion symptoms, and other imperfections, making it a promising technique for inspecting and maintaining bridge cables. A research project investigated various types of magnetic induction testing on different tension members made of single wires and evaluated the advantages and limitations of the MIT method. The study also explored the impact of factors such as cable diameter and measurement speed on the effectiveness of the technique. The results suggest that the MIT method can accurately detect defects in bridge cables and provide valuable information for maintenance and repair purposes. However, the article highlights the need for further research to optimize the MIT technique, particularly in automating the detection and characterization of signals, and to expand its applicability to a wider range of cable diameters and conditions.
Effect of salt water ageing on the degradation of steel‐composite bonded interfaces
Authors: Arouche Marcio Moreira , Feng Weikang , Karatsi Paraskevi , Kapteijn Tim , Pavlovic Marko
Published: September 2023

This work aims to investigate the long‐term effect of sea water conditions on the steel‐composite interface. The degradation of the steel‐composite bonded interface was investigated using fracture tests in coupon specimens. Specimens were manufactured and placed for ageing in a salt water solution to simulate the degradation of the bi‐material interface in offshore environment. Four‐point end notched flexure (4ENF) tests were performed to access the interface fracture behavior under quasi‐static loadings. Results of non‐aged and aged specimens show negligible degradation of the interface fracture properties after 69 days of immersion. In addition, steel plates were coated with resin and placed for ageing. The corrosion of uncoated and coated steel surfaces was inspected using optical microscopy. Results showed that the coated steel surface is susceptible to the environmental degradation. This indicates that the steel‐composite interface bonding will degrade after moisture reaches the steel surface.
The cable‐stayed footbridge in Prague ‐ Radotín
Authors: Janata Vladimír , Lahodný Jiří , Pecina Jan
Published: September 2023

The original, seriously damaged concrete footbridge across the Berounka River, which was in a state of disrepair, was replaced by an asymmetric 110 m long steel‐cable‐stayed footbridge using the adapted existing substructure. The 24 m high pylon consists of one tube asymmetrically pinned to the upper chord of the triangular lattice structure above the bearing sliding on the pillar. Another interesting solution is the termination of the ropes by sockets with a threaded bar and tendon, with a turnbuckle and a socket with pin which enable their convenient adjustment. The composite deck of the footbridge is a suitable alternative to timber or steel orthotropic one.
Wind hazard on earthquake damaged buildings
Authors: Athanasiou Anastasia , Dakour Mohamad , Tirca Lucia , Stathopoulos Ted
Published: September 2023

This study proposes a holistic approach to multihazard performance‐based assessment of a tall steel building, partially damaged by earthquake, and then subjected to wind. The case study is a 16‐storey LD‐CBF building in Montreal, designed in accordance with the Canadian code and steel standard. Advanced numerical models are developed in OpenSees; hence, they account for material nonlinearity including low‐cycle fatigue to simulate brace fracture. Wind histories are generated from wind tunnel data. The sequence of analyses is: (i) design the LD‐CBF building to respond to code‐based earthquake (2475 years return period) and verify the LD‐CBF members to design wind load (1‐in‐500 years), as well as, the interstorey drift under the service wind (1‐in‐10 years); (ii) apply the 60 min. wind load history on earthquake damaged building; (iii) assess the building response in terms of interstorey drift and residual interstorey drift, and (iv) compare the results of the case study under (1) earthquake on intact building, (2) wind on intact building, and (3) wind on earthquake damaged building. The findings are significant and allow the realistic representation of the effects of multiple hazards on steel buildings. In summary, the consequent hazard on building safety has a detrimental effect.
Ultimate behaviour of bolted beam‐to‐column connections in large rotations
Authors: Francavilla Antonella B. , Latour Massimo , Tan P.J. , Rizzano Gianvittorio
Published: September 2023

The capacity of steel Moment Resisting Frames (MRFs) to survive to extreme load is strictly linked to the moment‐rotation capacity of the beam‐to‐column connections. In those conditions, i.e., in extreme loading conditions, catenary actions develop in the connected beam leading in large joint rotations. The current European code, the Eurocode 3 Part 1‐8, neglects the regime of large joints rotations in the modelling leading to gross under‐ (or over‐) prediction of its response. In fact, recent works have shown that geometrical nonlinearity strongly influence the overall behaviour of connections when in large rotations range. To fill this knowledge gap, a mechanical model of a Double‐Split Tee Joint (DSTJ) that only considers material non‐linearity, is extended here to include geometric non‐linearity. To preliminary validate the mechanical model presented in the paper, an experimental test on a DSTJ has been performed and the result, both in terms of experimental data and mechanical prevision, has been compared. As a results, the updated mechanical model will be shown to be highly accurate in predicting the ultimate joint rotation (φ) and the maximum bending moment capacity (M) of the joint.