bluuebunny/crossref_metadata_2025_split huggingface dataset:
Shake Table Testing of Self‐Centring Concentrically Braced Frames
Authors: Goggins Jamie , Jiang Yadong , Broderick Brian M. , Salawdeh Suhaib , O'Reilly Gerard J. , Elghazouli Ahmed Y. , Alwahsh Hatim , Bogdanovic Aleksandra , Rakicevic Zoran , Gjorgjiev Igor , Poposka Angela , Petreski Borjan , Markovski Igor 
Published: September 2021

AbstractThe self‐centring system presented in this paper is a novel damage control technique designed to improve the resilience of concentrically braced frames (CBF) under seismic action. Namely, traditional CBFs can undergo large residual drifts following an earthquake event which can limit the opportunity for cost‐effective repair of the structure. Additionally, the gusset plates connecting the brace members to beams and/or columns can experience substantial rotations as a result of the compression buckling of the bracing members. Through the utilisation of post‐tensioning strands placed between flanges of beams, the novel self‐centring concentrically braced frame (SC‐CBF) system can return the frame to its original position after significant inelastic deformations experienced during large earthquakes, resulting in minimum residual drifts.In this paper, shake table testing of the aforementioned SC‐CBF system subjected to realistic earthquake loading is presented. The research is carried out as part of the H2020 “Seismology and earthquake engineering research infrastructure alliance for Europe” SERA project. Four sets of bracing configurations, incorporating varying square hollow section (SHS) braces and gusset plates were utilised in the shake table testing. Uniaxial loading with varying shake table accelerations was executed and the structural response evaluated using data from strain gauges (SG), load cells (LC), displacement transducers and accelerometers. The measured results provide information on the important parameters such as the tensile and compressive strength of the braces, post‐buckling capacity, gusset plate strains and post‐tensioning force. These findings are then presented and the crucial local and global response performance emphasised.
Cyclic loading in vertical stainless steel links
Authors: Chacón Rolando , Martínez Jean 
Published: September 2021

AbstractVertical links are dissipative devices in form of beam‐column segments that are included in eccentrically braced frames (EBF). Studies related to different configurations of links have been presented for carbon steel elements. Moreover, stainless steel is a nonlinear metallic material with particular appeal for its structural use due to a considerable amount of capabilities such as corrosion, circular life‐cycle, strength, ductility and aesthetics. Despite the increase on the use of stainless steel for structural elements in construction, the behavior of this material for structural purposes is not described as carbon steel in all applications. The elastic stiffness, maximum load, shear deformation capacity as well as the energy dissipation in long links are generally affected by the defined geometrical parameters. Due to the material nonlinearity, this influence may be affected considerably. In this paper, a numerical model aimed at depicting the cyclic behavior of vertical short and long links subjected to seismic lateral loads is presented. The model accounts for the material nonlinearity, the geometrical nonlinearity and the detailed definition of boundary conditions from the link connection to the EBF.
Seismic Design and Performance Assessment of Steel Frames Considering Joints' Behaviour
Authors: Lemma Melaku , Rebelo Carlos , Silva Luís 
Published: September 2021

AbstractSteel joints play an important role in the overall seismic behavior of steel frames. In the case of beam‐to‐column joints, the joints are composed of two regions: the connection where the beam and column are fastened together by mechanical means, and the panel zone, which is the region in the column web where deformation occurs. The deformations in the panel zone of the beam‐to‐column joint could significantly affect the seismic behavior of steel joints. In addition, the stiffness of the connection also plays a role. This paper aims to assess the effect of joint modelling on design and the seismic performance of steel moment resisting frames (MRFs) through nonlinear analyses using different modelling strategies. A parametric study is conducted on three steel moment resisting frames of 3, 6 and 9 storeys. These frames are designed for both gravity and seismic load cases according to the current Eurocodes. Beam‐to‐Column joints are designed and characterized based on the pre‐normative design recommendations obtained in the scope of the Equaljoints project. Consequently, simplified modelling methods that disregard the joints, and refined modelling techniques that account for the joints' dimension and behavior are adopted for three different joint types classified based on stiffness and strength of the joints. A systematic assessment of the performance of each frame is assessed through nonlinear analyses. An integrated design and performance assessment tool is developed in Python and implemented using OpenSees.
Experimental assessment of bolted T‐stubs under cyclic loading
Authors: Oliveira Sara , Costa Ricardo , Rebelo Carlos , da Silva Luís Simões 
Published: September 2021

AbstractA rational and efficient seismic design requires a detailed characterization of the members and joints behaviour. The prediction of moment‐rotation response of steel beam‐to‐column joints under cyclic loading is not fully addressed in EN 1993‐1‐8 nor EN 1998‐1. Additionally, EN 1998‐1, requires experimental evidence for the use of dissipative steel beam‐to‐column joints. Therefore, new design tools are required to predict the cyclic behaviour of beam‐to‐column joints. In the scope of the European projects “EQUALJOINTS – European preQUALified steel JOINTS” and “EQUALJOINTS+ ‐ Valorisation of knowledge for European prequalified steel joints” a software that provides analytical predictions of cyclic and monotonic response of prequalified steel beam‐to‐column joints was developed. This software embodies the cyclic component method (CCM), which is an extension for cyclic loading of the component method, coded in EN 1993‐1‐8. The cyclic behaviour of the components, required to feed the CCM, can be gathered from experimental tests using specimens similar to the component to be characterized, e.g. T‐stubs. With this objective an experimental campaign on 14 T‐stubs was conducted at University of Coimbra. Results from tests and assessment of available models are presented in this paper.
Cyclic Behavior of Tubular Steel Columns with High Yield‐to‐Tensile Strength Ratio under Asymmetric Loading Protocols
Authors: Hamauzu Shingo , Skalomenos Konstantinos A. 
Published: September 2021

AbstractThis paper investigates the cyclic behavior of steel columns subjected to single‐sided cyclic loading protocols driven by residual deformations. First, nonlinear time‐history analyses are performed to steel framed structures using a set of repeated earthquakes. Then, based on the dynamic analysis results, a set of single‐sided loading protocols is developed to envelop the asymmetric seismic behavior of the examined frames. The developed protocols are used to identify the new single‐sided capacity margins of steel columns in terms of strength and ductility as well as evaluate the potential of using novel high‐strength materials. In this paper: (a) the new asymmetric loading protocols are proposed based on the seismic behavior of three medium‐rise frame buildings with different beam‐to‐column strength ratios (i.e. Mpc/Mpb) which are analyzed with the aid of the finite element analysis (FEA) software ABAQUS; (b) a computational databank of the inelastic responses of square tubular steel columns with high yield‐to‐tensile (YT) strength ratio is developed by subjecting column FEA models with various width‐to‐thickness ratio and axial loads to both conventional and asymmetric cyclic loading protocols. Due to the asymmetrical nature of the cyclic protocols, a lower post‐peak strength deterioration was observed in columns that enables the definition of new, extended, ductility capacity margins. The ductility capacity ratios under the asymmetric loading protocols were found to be 1.15 to 1.71 higher than those obtained under the conventional protocols enabling the use of high‐strength steels in steel columns of smaller width‐to‐thickness ratio.
Lateral‐torsional buckling of a stiffened beam with semi‐rigid joints
Authors: Vild Martin , Bajer Miroslav , Barnat Jan , Šabatka Lubomír , Wald František 
Published: September 2021

AbstractThe paper presents an experiment and a numerical analysis of a steel beam subjected to three‐point bending. The beam was connected to short column stubs by bolted end plates. The joints were designed as semi‐rigid and their influence on the lateral‐torsional buckling resistance of the beam was evaluated. The cross‐sections of the beams and the columns were IPE 180 and HEB 140, respectively. The columns were 1 m long and were rigidly connected to the loading frame at their ends. The beams were 3.3 m long and were loaded at midspan. 9 beams were tested in total, from which 3 beams were without any stiffeners, 3 beams had two inclined stiffeners welded prior to the test, and 3 beams upon which the stiffeners of the same geometry were welded under load equal to 50 % of the bending resistance of the unstiffened beam. The stiffeners were at one third and two thirds of the beam span. The experiment was modelled in software using Component‐based Finite Element Method. Shell elements were used for plates and special nonlinear springs and interpolation links for simulation of bolts and welds. Geometrically and materially nonlinear analysis with imperfections was used. The experimental results were compared to the model. A sensitivity study with various levels and kinds of initial imperfections was performed.
Buckling resistance of compression members with back‐to‐back connected angle sections
Authors: Beyer André , Bureau Alain , Jaspart Jean‐Pierre 
Published: September 2021

AbstractThis paper focusses on the buckling resistance of compression members made of back‐to‐back connected angle sections. The studied built‐up members are connected through bolted packing plates. Due to the flexibility of this connection, these members generally do not fully work as a single member but the connection stiffness has to be accounted for. In Eurocode 3 Part 1‐1 it is currently admitted to neglect the effect of the connection stiffness if the packing plates possess a maximum distance of 15 imin (imin is the minimum radius of gyration of one individual angle section, also called “chord”). Elsewise the influence of the packing plates on the member resistance should be accounted for. The limit distance of 15imin appears to be much lower than the past practice, consequently leading to a more conservative design and a complexification of the fabrication. This paper therefore presents a sensitivity analysis focusing on the influence of several parameters as: the distance of packing plates, the presence of clearance in bolt holes and the influence of preloaded bolts. These parameters are studied with a numerical model based on solid finite elements. Owing to the use of solid elements, it is possible to model explicitly the bolts, the packing plates and all contact regions.
Interaction of geometric and material nonlinearities in stainless steel frames
Authors: González‐de‐León Isabel , Arrayago Itsaso , Real Esther 
Published: September 2021

AbstractAdequate mechanical properties make stainless steel an excellent construction material for structures. The current stainless steel European structural code EN1993‐1‐4 (2015) is largely based on provisions given for carbon steel EN1993‐1‐1 (2005) and does not establish specific design rules for the global analysis of stainless steel structures. Thus, the same classification criterion applies in both codes for sway and non‐sway structures, as well as providing the same predicting expressions for the amplification of bending moments in basic structures, despite the considerable differences between the mechanical behaviour of these two materials. However, recent numerical research on stainless steel frames with H cross‐sections by Walport et al. (2019) showed that the degradation of stiffness due to material nonlinearities considerably affects the response of stainless steel frames, causing greater deformations and increasing second order effects.In order to contribute to the optimal design of stainless steel structures, this paper investigates the influence of the nonlinear material response of stainless steel alloys on frame‐type structures with Rectangular Hollow Sections based on the experimental results conducted by Arrayago et al. (2019), and the interaction of material and geometric nonlinearities.
Lateral torsional buckling of an I‐shaped hoisting spreader beam
Authors: Snijder Hubertus H. , Ploegmakers Dirk , Dekker Rianne , Maljaars Johan 
Published: September 2021

AbstractI‐shaped hoisting spreader beams are widely used in practice when lifting heavy objects by crane. In general, I‐shaped beams that are subjected to a bending moment may be sensitive to lateral torsional buckling. Eurocode 3 (1993‐1‐1 [1]) provides a calculation method to determine the lateral torsional buckling resistance using buckling curves. The method requires the elastic critical moment to calculate the relative slenderness. Different solutions for elastic critical moments are available which usually require fork end conditions. However, hoisting spreader beams do not have fork end conditions nor do they have lateral supports. Thus, the available calculation methods cannot be used and a new method is developed. A numerical model is validated against an experiment and subsequently used to investigate different types of spreader beam configurations. First a method to determine the elastic critical moment of a hoisting spreader beam is developed. Then the lateral torsional buckling resistance is evaluated using the buckling curves. The applicable buckling curve is determined by choosing the least conservative curve that can be used with a partial factor of 1.0. This results in buckling curve d to evaluate the lateral torsional buckling resistance of hoisting spreader beams.
Simplified design method for stiffened cellular beams against web‐post buckling
Authors: Glorieux Antoine , Cajot Louis‐Guy , Hanus François 
Published: September 2021

AbstractWeb‐post buckling next to Vierendeel effect, is one of the main failure modes for cellular beams. Several solutions are available to avoid web‐post buckling, such as ring stiffener or infill opening. A new cost‐effective solution is to weld a vertical plate stiffener on the web‐post. This plate stiffener should bring enough inertia to prevent buckling. It is not necessary that the plate stiffener is welded to the flanges, so it does not require as accurate cutting as a ring stiffener or an infill opening. An analytical method is proposed to calculate the bearing capacity of such a stiffened cellular beam. This consists in an adaptation of the existing design method presented in prEN 1993‐1‐13 for steel beams and in EN 1994‐1‐1: Eurocode 4 Annex Composite beams with Web Openings for composite beams. The analytical method has been compared to a numerical parametrical study using Finite Element software SAFIR®. Influence of various parameters has been studied. Results show that depending on the geometry, vertical stiffeners can increase the bearing capacity of the beam up to 35%. In all modelled cases, the stiffener avoids the web‐post buckling. Two main webpost failure modes were identified, buckling of the first unstiffened web‐post (generally when only one web‐post is stiffened) and bending of the first stiffened web‐post. For the latter, a verification has been added in the analytical method. Additionally, a cost analysis has been performed to compare different solution to increase the bearing capacity of the beam.
Rotational Stability of Plastic Hinges
Authors: Roberts Michael J , Davies J Michael 
Published: September 2021

AbstractThis paper is part of a larger project that considers the design of large steel‐framed warehouses and distribution centres (‘Big Sheds’) in the context of the SCOSS Alert “Effects of Scale” [1]. These buildings are currently designed to Standards and design procedures that were intended for much smaller structures, and are now long out of date. In the UK, the steel frames of such buildings are generally designed on the basis of plastic theory [2], the fundamental research initiated at the University of Cambridge being continued under Horne at the University of Manchester and culminating in the publication in 1981 of Horne and Morris [3]. Since that date, design procedures have largely stood still while Big Sheds have increased enormously in both scale and complexity. In the UK, plastic design is still largely used; while the early design procedures have been automated so that the entire calculation can be dedicated to a computer. Nevertheless, the fundamental plastic design procedures have changed little. In this context, which is continuing to evolve, this paper returns to the fundamentals and questions some of the basic premises. Current design procedures, based on laboratory tests on small stocky sections, can only be extrapolated to the contemporary situation with the aid of advanced numerical modelling and this process has only just begun. Even at this early stage of the research, it is suggested that the use of plastic theory for the design of large structures typified by Big Sheds needs serious reconsideration.
Holistic Life‐Cycle Analysis of Bridge Solutions
Authors: Zinke Tim , Hechler Oliver , Rademacher Dennis 
Published: September 2021

AbstractSteel in bridge constructions is often associated with very large span bridges due to its favorable relationship between strength and weight. But even for bridges with small and medium spans of up to 60 m, steel combined with concrete as a composite bridge can lead to economically justifiable constructions, especially when the performance during the complete life‐cycle is integrated. In this paper, two life‐cycle oriented calculation methods (life‐cycle costs and external costs) are introduced and applied. As a result, comparisons between two abutment solutions (conventional reinforced concrete abutment and a permanent steel sheet pile abutment) and two superstructure variants (steel composite construction and in‐situ prestressed concrete superstructure) are presented. It is shown that accelerated construction processes, durable materials, and a smart bridge‐design considering actual technological developments lead to economically advantageous solution for traffic infrastructures.
Optimized welding processes for the repair and strengthening of structures made of old mild steels
Authors: Sieber Lars , Flederer Holger 
Published: September 2021

AbstractWhen repairing or reinforcing existing structures made of old mild steel, the preferred joining method may be welding rather than bolting, as is usually the case. Due to the specific properties of old mild steels, special problems have to be considered. The weldability of old mild steels is particularly influenced by their highly scattering chemical composition, existing inclusions and their distribution in the component as well as their limited material toughness.The first results of a research project at the Dresden University of Applied Sciences concerning the weldability of old rimmed mild steels have already been presented at Eurosteel 2017. This paper presents the findings of continued investigations, e.g. the use of other filler materials or out‐of‐position welding. The welding parameters were adjusted so that the toughness of the HAZ is better than in the unaffected base material.Additionally, the suitability of flux‐cored wire welding of old mild steels was investigated. This welding process enables a more economical production of large seam lengths. Unfortunately, the realized process parameters are very stringent, as the higher energy density of this process quickly leads to coarse grain formation in the HAZ and thus to a reduction in toughness.
Stiffness of equal width welded I‐beam to RHS column connection
Authors: López‐Colina Carlos , Serrano Miguel A. , Lozano Miguel , Gayarre Fernando L. , Suárez Jesús M. 
Published: September 2021

AbstractDespite some recent efforts, the use of mechanical approaches like the component method for the rotational stiffness of connections is still not present in the design codes for hollow sections. In addition, the easiest way to obtain semi‐rigid connections with high rotational stiffness or even rigid ones with I beams and RHS columns is to design both members with the same width. In this way, loads are transferred almost directly from the beam flanges to the side walls of the RHS, avoiding the high rotations due to the bending of the front face of the RHS. Considering all this, some experimental tests have been used by the authors to validate a finite element model that simulates equal width connections in which the component ‘lateral faces of RHS’ under transverse forces was the main source of beam rotation. This was selected as the most important component to be considered in the welded joints between I beams and RHS columns when they have the same width. Then, some different analytical approaches for its stiffness have been assessed by comparing them with the experimental and numerical results. This work finally proposes a design equation for the ‘lateral faces of RHS in tension or compression’ in order to be applied in a future unified proposal for the component method including hollow sections. In addition, a rotational stiffness approach for the equal width welded I‐to‐RHS connections has been directly derived from this.
Peculiarities of resistance definition for welded offset T‐joint between RHS members
Authors: Kalmykova Svitlana , Wald František 
Published: September 2021

AbstractSteel structural hollow sections, including rectangular hollow sections (RHS), are nowadays one of the most efficient load‐bearing elements of the lattice structures. Despite its widespread application, there is still lack of design techniques for joints produced with offsets. The article intends to eliminate gaps in knowledge about the mechanical resistance and design of so‐called offset RHS joints, welded T‐joints composed from rectangular hollow sections with a certain lateral offset of a brace from a centreline of a chord, under brace axial compression. The paper presents results of numerical investigations of structural behaviour of the mentioned joints in comparison with existing analytical methods of connection nominal resistance determination for both standard (co‐axial) and offset welded RHS joints. For validation purposes, the full‐scale laboratory tests were conducted. Numerical models were created using a general FE programme Abaqus and a component‐based FE programme IDEA StatiCa. Particular attention was given to mesh size effect and weld seam modelling. The curve fitting analytical model complying to prEN1993‐1‐8:2020 proposed by Wei and Packer [1] is verified by numerical experiments. The limits of validity of considered analytical model are examined and proved by calculations.