bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ductility and Buckling Behaviour of Point‐by‐Point Wire Arc Additively Manufactured Steel Bars
Authors: Silvestru Vlad‐Alexandru , Ariza Inés , Taras Andreas 
Published: September 2022

AbstractThe wire arc additive manufacturing (WAAM) technology in combination with computational design shows a big potential for realising novel force‐flow optimised and material‐efficient connections. This contribution deals with point‐by‐point WAAM, a material deposition strategy that allows to place material precisely where structurally needed or aesthetically desired. This could be applied, among others, for realising a novel optimised type of steel nodes between custom‐oriented profiles, as they occur in freeform steel‐glass grid‐shells. In this paper, the structural behaviour of robotically fabricated straight WAAM steel bars under uniaxial tensile and compressive loading is discussed. The focus is set on the ductility exhibited by such components as well as on the buckling behaviour observed under compressive loading. Experimental tests were conducted, both under tensile and under compressive loading to assess the influence of the irregular geometry on the structural performance. Furthermore, it was studied to what extent a prediction of the ductile structural behaviour, of the compressive load‐bearing capacity and of the post‐buckling behaviour is possible by finite element simulations. This contribution presents and discusses highlights of the obtained results.
Assessment of Design Approaches for Stainless‐Steel Joints Through an Equivalent FE Modelling Technique
Authors: Sarfarazi Sina , Shamass Rabee , Della Corte Gaetano , Guarracino Federico 
Published: September 2022

AbstractConsidering the significant strain‐hardening and ductility characteristics of stainless steel and the influential role of beam to column joints in the overall response of structures, a clear understanding of their moment rotation behaviour appears fundamental. In the present study, a review of the European design code for three typical semi‐continuous beam‐to‐column joints (extended end plate, flush end plate and top‐and‐seat angle connections) is first carried out. Then, using a hybrid modelling strategy with uncoupled elastic‐plastic springs for the bolts and shell elements for the members, more refined 3D finite element (FE) models are developed and validated against available test results. An equivalent stress definition is then proposed for calculating the joint moment resistance. Finally, the initial rotational stiffness, moment resistance, rotation capacity, and failure patterns are used to evaluate critically the accuracy of the predictions of the European design code. As a result, the need for more comprehensive design guidance in accordance with the observed findings is pointed out.
A Novel Residual Stress Model for Welded I‐sections and the Influence on the Stability Behaviour
Authors: Schaper Lukas , Tankova Trayana , Knobloch Markus , da Silva Luís Simões 
Published: September 2022

AbstractResidual stresses have a marked influence on the stability behavior of steel members. Previous studies have shown that the structural behavior depends on both the distribution and the size of residual stresses. The residual stress distribution is affected by the cross‐section geometry, the steel grade and the manufacturing process, e.g. flame cutting and the welding procedure. A realistic consideration of residual stresses is necessary for economic models for design purposes and a safe design of steel structures.This paper presents an experimental and numerical study on the influence of residual stresses on the stability behavior of structural members, i.e. steel columns and beams. A novel residual stress model for welded I‐shaped sections was developed and evaluated using test data. This model takes into account the main influencing parameters, i.e. the cross‐sections geometry, the steel grade as well as manufacturing process with thermal cuts or non‐thermal cuts of the steel plates. The novel residual stress model is then used to investigate the structural stability behavior in terms of a numerical simulation study. The result of the study allows to propose an improvement of the buckling curve selection for welded high strength steel columns and beams.
Influence of Welded Joints Modelling on the Structural Response of Steel Frames under Fire Situation
Authors: Segura Guillermo , Arrayago Itsaso , Mirambell Enrique 
Published: September 2022

AbstractSteel frames with compact cross‐sections usually fail describing a plastic failure mechanism, redistributing internal forces. In order to fully form a plastic failure mechanism, the designed joints must be able to withstand the increase in stresses resulting from the redistribution of internal forces and to provide enough stiffness to prevent large second order effects. According to current European codes, full‐strength joints can be modelled as perfectly rigid joints and for structures with Class 1 cross‐sections carrying out a plastic analysis is allowed. Both of these statements have been widely studied at room temperature but whether these assumptions are valid under fire situation needs to be assessed yet.With this goal in mind, this paper presents a numerical study comparing the response of steel frames for which the welded joints between members are accurately modelled with the results for frames with perfectly rigid joints, both at room temperature and at elevated temperatures. The obtained results show that modelling full‐strength joints as perfectly rigid joints for numerical purposes can also be done under fire situation without major differences in the structural response. Moreover, all the analysed Class 1 frames could form a fully plastic mechanism under fire situation.
Design of Steel Columns in Fire using Second‐order Inelastic Analysis with Strain Limits
Authors: Murtaza Hasan , Kucukler Merih 
Published: September 2022

AbstractIn this paper, a structural steel fire design approach using second‐order inelastic analysis with strain limits is proposed and applied to the design of steel columns in fire. The proposed design approach employs beam finite elements to conduct a second‐order inelastic analysis. Within the proposed method, strain limits are used to account for the effects of local buckling; while global instability, the loss of strength and stiffness and thermal effects are fully considered through second‐order inelastic analysis carried out using beam finite elements. The proposed method is assessed against validated shell FE results. It is observed that the proposed design approach provides consistently accurate and safe capacity predictions for steel columns in fire.
Stainless Steel Portal Frame Tests
Authors: Jůza Jan , Jandera Michal 
Published: September 2022

AbstractExperiments on stainless steel frames were carried out within this research. In total, 5 portal frames made of austenitic stainless steel SHS/RHS were tested. The paper thoroughly describes the performance of the loading tests including the layout of auxiliary elements and measuring devices. The technical drawing of the experiment layout with a description is presented as well as several photos. The load‐bearing capacities of the frames are summarised in a table. The research aims for a global structure behaviour examination with a particular focus on stainless steel structures. Their behaviour is highly influenced by nonlinear material stress‐strain response. Material nonlinearity leads to loss of stiffness, which results in greater deflections. And greater deflections generate greater second‐order effects. Worldwide research show this particularity needs to be taken into consideration when conducting a global analysis of the structure.
Numerical Study on the Buckling Resistance of High Strength Steel Columns and Beam‐columns
Authors: Filho José Osvaldo Ferreira , Tankova Trayana , Carvalho Hermes , Rodrigues Filipe , da Silva Luís Simões 
Published: September 2022

AbstractThe rising interest in the use of high strength steel (HSS) materials is justified by several advantages that they provide. In the field of construction, their benefits range from streamlined and elegant structures to lower CO2 emissions and energy consumption. High‐rise buildings and large span bridges can be designed with smaller foundations and less structural weight, since the application of HSS makes the design with slender steel sections possible. However, special attention should be given to the stability of the compressive members since the buckling resistance generally governs their design. The existing codes to evaluate the capacity of HSS columns and beam‐columns are based on rules from experimental tests related to normal strength steel (NSS) materials, which is responsible for inconsistencies. Therefore, this current work aims to present a numerical model created and validated to evaluate the major‐ and minor‐axis flexural buckling of HSS welded I‐section columns and the combined flexural and lateral‐torsional buckling of HSS welded I‐section beam‐columns. In the following, a parametric study is also conducted, in which different cross‐sections, normalized slenderness, steel grades (from S460 up), bending moment distributions and application of restraints are considered. Finally, a comparison between the European design rules and the resistances from the Finite Element model is led, evidencing the underrating expressed by the code with a level of safety even higher when superior steel grades are evaluated.
Investigation on Shear Buckling of Corrugated Web Beams with Reinforced Web Openings
Authors: Wang Jian , Li Zheng , Robra Jörgen , Pasternak Hartmut , Euler Mathias 
Published: September 2022

AbstractCorrugated web beams are welded I‐sections with thin‐walled sinusoidal corrugated webs and flanges made of wide flat steel that have been developed as an alternative to steel girders with flat webs. In comparison with hot‐rolled or welded I‐beams with flat webs, corrugated web beams are connected with considerable material savings and fully automated production. Assuming the same load‐bearing capacity, corrugated web beams are lighter than those with a flat web, since the corrugated web beams can often be loaded up to their plastic resistance without reinforcement of the web. The research on the load‐bearing behavior of corrugated web beams without web openings is relatively mature. However, the resistance of corrugated web beams with reinforced web openings, as they are often used in buildings for installations, has not well experimentally been investigated, yet. This paper deals with the shear resistance of corrugated web beams with reinforced square web openings. Three specimens of different geometry with two square web openings were tested. The experiments are compared with a Finite Element Analysis by Abaqus® and with an analytical model allowing simplified calculation. Both models can relatively accurately calculate the shear resistance. The experimental and numerical results show that the increase of the shear resistance of perforated corrugated web beams depends on the wall‐thickness and the steel grade of the web opening reinforcement.
Component Test, Fracture Simulation and Experimental Study on Steel and Shear Panel for Seismic Resistance
Authors: Gashi Ferit , Bontempi Franco , Petrini Francesco 
Published: September 2022

AbstractThis paper summarizes the experimental campaign carried out for the development of a new steel energy dissipative devices named Slit Dampers (SDs) designed for earthquake protection of structures. SDs consist in shear steel plates with appropriately shaped cut‐out portions of material for allowing maximum spread of plastic deformation along the device and then maximizing the hysteretic dissipative behavior. A total of eighty‐two steel shear plates with different openings and thicknesses are tested to investigate their behavior under cyclic pseudo‐static loading. Six types steel shear plates are studied, including the SD with narrow slits that divide the plate into rectangular links, and the butterfly fuse with a diamond‐shaped opening that create butterfly shape links in the plate. Other varying test parameters are: loading rate, material strength, and the number of in‐parallel damper elements. It is expected that the proposed model can be successfully used to predict the behavior of dampers in real‐world applications.
Seismic Fragility Curves of Steel Frames Equipped with Easily Repairable Dissipative Devices
Authors: Giuliani Giulia , Andreotti Roberto , Tondini Nicola , Bursi Oreste S. 
Published: September 2022

AbstractThis paper provides insight into a probabilistic demand analysis of a steel‐concrete structures equipped with novel dissipative components. DISSIPABLE components were studied in the framework of a European Research Fund for Coal and Steel (RFCS) project, funded to test large‐scale structures in which the dissipation is concentrated in specifically designed elements that act like a fuse and can easily be replaced after a seismic event. Incremental Dynamic Analyses (IDAs) were performed to investigate the influence of equipping steel frames with two different dissipative seismic devices, namely the Dissipative Replaceable Beam Splice (DRBeS) and the Dissipative Replaceable Link Frame (DRLF). The benchmark models were calibrated on the results of laboratory full‐scale tests, carried out in the project framework. In addition, the DISSIPABLE frame behaviour was compared with a state‐of‐the‐art moment‐resisting frame, designed according to the capacity design philosophy. Probabilistic demand models were developed, and seismic fragility curves were then derived to compare the behaviour of the analysed structural systems.
Numerical Analysis for Push‐Out Test with Y Type Perfobond Shear Connectors
Authors: Mefleh Wajdi , Kovács Nauzika 
Published: September 2022

AbstractThis paper focuses on the Y type perfobond shear connectors of steel‐concrete composite beams with the aim to investigate the influence of the structural parameter of the connection to the resistance and ductility of the structures. The Y shaped shear connections are a new shape developed with the benefits of resisting a higher shear force by the transversal bars and a bigger area of the concrete dowels surrounded by the Y shaped plate. This type of shear connection has significant resistance against vertical separation. In this paper, an advanced finite element model for a push‐out test with a Y type perfobond shear connector has been developed and validated by the experimental test. The aim of this research is to investigate different parameters such as the concrete strength, perfobond yield stress, the existence of the transversal bars on the structural behavior. The results showed that the concrete strength has a major effect as using a higher concrete resistance gave a higher ultimate resistance with a higher ductility. The existence of the transverse bars shows a major effect on the ductility load level. On the contrary, the effect of changing the diameter of the bars on the ductility load level was slightly noticeable. While using deferent steel grades for the perfobond plate significantly affected the ultimate resistance, but not the ductility load level. In further studies more parameters will be checked, and a formula and a guideline could be developed for a design purpose.
Parametric Finite Element Analyses of Lightweight Cold‐formed Steel‐concrete Composite Floor Beams
Authors: Lukačević Ivan , Ćurković Ivan , Rajić Andrea , Žuvelek Vlaho 
Published: September 2022

AbstractComposite structural systems have many benefits, such as a high degree of prefabrication, reusability and long span capability. The main advantage of such systems is manifested through the optimal utilisation of structural steel and concrete. Additionally, allowing for demountability and reusability, the system can also result in a much smaller carbon footprint at the end of life. These advantages are particularly emphasised with the implementation of cold‐formed steel sections. This paper presents an innovative solution for a composite floor structure system consisting of built‐up cold‐formed profiles and concrete slabs made with profiled sheets. The influence of the corrugated web thickness, type of connection between steel beam elements, the degree of shear connection and steel beam height on the overall behaviour of the composite system is analysed. The performed FE analyses showed that the influence of connections between steel beam elements and the degree of shear connection had the most significant impact on system behaviour. In contrast, the steel beam height, the corrugated web thickness and spot weld density had less influence on the analysed composite system behaviour. The obtained results provide the basis for implementing laboratory research on the proposed system.
New Consistent Set of Design Equations for Equal‐leg Angle Sections and Members
Authors: Bezas Marios‐Zois , Jaspart Jean-Pierre , Vayas Ioannis , Demonceau Jean-François 
Published: September 2022

AbstractAngles profiles have been used since the very beginning of the steel construction due to their easy production, transportation, and ability to be connected. However, they exhibit some specific features that clearly distinguish them from other types of common sections, as they are monosymmetric sections with very small constants in both torsion and warping, their bending capacity and radius of gyration around the weak axis are substantially lower compared to the strong axis ones, their legs are possibly susceptible to local buckling, their plastic resistances are significantly higher than their elastic ones and finally, due to the eccentric connection in one leg, they are also subjected to bending when used as single members.The above‐listed features confirm that existing common design rules for other mostly doubly symmetric type of sections cannot safely cover angle sections, what inevitably leads to the need for development of specific design provisions for angles. Therefore, extensive experimental, analytical, and numerical studies have been conducted to propose a complete and duly validated set of design rules covering all aspects of their design (classification, cross‐section and member resistance). The proposed rules will be included in the forthcoming version of EN1993‐3.
GBT‐based Stability Analysis of Thin‐walled Members with Circular Axis
Authors: Peres Nuno , Gonçalves Rodrigo , Camotim Dinar 
Published: September 2022

AbstractThis paper presents a newly developed extension of the linear Generalised Beam Theory (GBT) formulation for members with circular axis, previously developed by the authors, to the linear stability analysis case. This extension incorporates the classic GBT kinematic assumptions, which ensure efficiency without sacrificing its accuracy. The finite element implementation of the proposed formulation makes it possible to calculate bifurcation loads and associated buckling mode shapes of members with circular axis and arbitrary flat‐walled cross‐sections, undergoing global‐distortional‐local deformation, with great accuracy and computational savings (with respect to refined shell finite element models). Moreover, it is shown that the remarkable GBT modal decomposition features, stemming from the fact that the kinematic description of the beam is based on a superposition of structurally meaningful cross‐section deformation modes, enable an in‐depth insight into the nature of the buckling modes in curved members.
Elastic Local Buckling Strength of Wide Flange Beams Web Subjected to End Moment and Distributed Load
Authors: Nakano Tomoki , Ikarashi Kikuo , Mitsui Kazuya 
Published: September 2022

AbstractThe buckling modes of wide flange beams are classified as lateral buckling and local buckling. AIJ Recommendations for Stability Design of Steel Structure [1] for these buckling modes are based on elastic buckling strength. It is therefore important to understand the elastic buckling strength and buckling modes of wide flange beams. The current design specifications make provisions based on simple stress states such as uniform compression and pure shear stress. For long‐span beams, which are currently used in many structural members, dead loads dominate in short‐term loading. However, few studies have considered stress changes due to distributed loading, and the specifications do not adequately consider actual design situations. The aim of this study is to determine the elastic local buckling strength of the web of wide flange beam subjected to uniformly distributed load and end moments. The subject is the web with 4 edge fixed support and the analysis method is a theoretical analysis using the energy method. By considering the difference between the maximum positions of bending stresses and shear stresses, the buckling strength and buckling mode could be correctly determined. The shear buckling coefficient enabled a unified classification of the buckling modes.
On the Choice of Eigenmode Shapes for Interactive Cases of Local and Global Buckling of RHS/SHS and I‐Shaped Sections
Authors: Müller Andreas , Vild Martin , Taras Andreas 
Published: September 2022

AbstractBetter and simpler possibilities of structural optimization due to increasing computational power but also for reasons of environmental sustainability, the use of materials and their reusability lead to greater acceptance towards more advanced numerically intensive, so‐called “design by analysis” methods like geometrically and materially nonlinear analyses with imperfections (GMNIA). The general choice of imperfections and their combination in such models, especially for slender cross‐sections of intermediate length prone to an interaction between a global and local plate‐buckling, is crucial in terms of the reached load‐bearing capacity. Annex C of EN 1993‐1‐5 make use of the “70%‐rule” for the combination of imperfection modes and amplitudes. This rule postulates that two GMNIA calculations should be carried out when local and global interactive buckling may be dominant; one with 100% + 70% of the maximum specified amplitude in either case. In addition, extended information is provided on the choice and combination of imperfections in the newly introduced and currently available draft of the prEN1993‐1‐14:2020 (Design assisted by finite element analysis). Although information is provided how the local and global imperfections should be combined, it is not stated when it is relevant to consider those. Based on carried out GMNIA simulations on SHS/RHS and I‐shaped sections, this paper presents a general decision support on the choice of equivalent imperfections. Based on numerical analysis, the developed flowchart and design routine allows for the decision whether the consideration of the interaction of local and global imperfections is required or not.
An Elasto‐plastic Finite Element for the Analysis of Planar Steel Beams
Authors: Nedelcu Mihai 
Published: September 2022

AbstractThe following paper presents an original finite element formulation for the elasto‐plastic analysis of planar homogeneous isotropic beams. The one‐dimensional elastic‐perfectly plastic material behavior is considered. The approach is based on innovative shape functions able to capture the formation of elasto‐plastic regions at the ends of the beam element. While the proposed shape functions can theoretically handle any cross‐section, in this paper the formulation is developed only for rectangular cross‐sections. Linear geometric behavior is considered. The formulation is validated by comparisons with the upper bound method of plastic limit analysis in terms of ultimate loading, and with simulations using shell FE analyses in terms of load‐displacement response and development of the plastic regions.