bluuebunny/crossref_metadata_2025_split huggingface dataset:
Economic benefit of high strength steel sections for steel structures
Authors: Saufnay Loris , Jaspart Jean‐Pierre , Demonceau Jean‐François 
Published: September 2021

AbstractThe present work aims at studying the field of interest of high strength steel rolled sections (fy>460 MPa) for steel structures from an economic point of view. Whilst these high strength steel profiles do not exist yet, steelmakers are able to produce more resistant steels through more efficient production processes and a future emerging of these particular steel profiles is likely to occur. The use of this kind of steels can lead to a significant material saving. So, the use of high strength steel leads to lighter structures requiring smaller foundations, lower transportation and construction costs but also emitting less CO2. However, buckling, fatigue or deflection requirements often reduce the advantage of high strength steels. It is for this reason that the designer is sometimes reluctant to use them. A study establishing the areas of economic benefit of high strength steel tubes in steel and composite structures had already been carried out at the University of Liège [8]. The goal of the present is to extend this study to rolled sections (H‐shape and I‐shape). It therefore consists in providing methods in order to help the designer determining the economic benefit of high strength steel for structural elements subjected to different loadings. These ones are then used to determinate the areas of economic benefit of the high strength steels in comparison to regular steel, depending on their relative costs.
Numerical and Theoretical Modelling of the Web‐Post Buckling of Stainless Steel Cellular Beams
Authors: Shamass Rabee , Guarracino Federico 
Published: September 2021

AbstractCellular steel beams are widely used in modern constructions to achieve long spans and to provide passage for service installations such as ducts and cables. The present paper is concerned with the use of stainless steel in cellular beams. In fact, available design methods to calculate the shear strength of web‐post are applicable only to carbon steel that exhibits a linearly‐elastic behaviour with a clear yield point followed by plastic deformation with little amount of strain hardening. Conversely, stainless steel exhibits a non‐linear stress‐strain relationship with high level of strain hardening. Consequently, new design provisions for the web‐post buckling of cellular beams made from stainless steel capable of exploiting the material strain hardening are highly desirable. Since no experimental investigations are available in literature for cellular beams made from stainless steel, finite‐element models have been developed and validated against tests conducted for carbon steel cellular beams. The structural behaviour of stainless steel cellular beams with various geometries and material characteristics is investigated through a large number of finite element analyses and a simple mechanical model for the Web‐Post Buckling (WPB) failure is developed and calibrated against the numerical results to provide the basis of a reliable design method.
Experimental and numerical investigations on the rotation capacity of high strength steel beams
Authors: Bartsch Helen , Pauli Gesa , Eyben Felix , Schaffrath Simon , Feldmann Markus 
Published: September 2021

AbstractIn order to design efficient and highly utilised sections, the plastic/plastic design approach depicts a valuable tool. Concerning plastic design, Eurocode 3 requires only Class 1 cross‐sections and material grades up to S460, depicting conventional strength steels (CSS), to be used. High strength steels (HSS) with yield strengths up to 700 MPa are not considered appropriate for plastic design due to their lower ductility. However, the exclusion of HSS appears to be unnecessary in the light of recent test results. Experimental investigations on 20 homogeneous and hybrid high strength double symmetric I‐section beams have been conducted comprising various slenderness characteristics of flange and web and different span lengths. The results show that the rotation capacity value of R = 3, currently required by EC3 regulations, can actually be achieved by high strength steel beams depending on their cross‐sectional characteristics. Additionally, the experimental tests have been recalculated numerically. The material characteristics of the models have been defined by flow curves, which have firstly been calibrated on the basis of small‐scale tensile tests and furthermore slightly fitted to the full‐scale test results. Ductile material failure in terms of crack initiation and evolution is considered by incorporating a damage mechanics model. It can be shown that experimental and numerical results show very good accordance.
Stability of Open‐Top Cylindrical Steel Tanks with Primary Stiffening Ring under Wind Loading
Authors: Zeybek Özer , Topkaya Cem , Rotter J. Michael 
Published: September 2021

AbstractCylindrical steel tanks are very thin shell structures and vulnerable to buckling under external pressure due to wind or partial vacuum due to rapid emptying or blocked vents when they are either empty or partially emptied. A primary stiffening ring is commonly used at or near the top of the tank wall to increase its strength against external pressure instability. Most traditional design treatments largely ignore the non‐uniform circumferential variation of the wind and treat the tank as subject only to uniform external pressure when sizing the primary stiffening ring. Moreover, the interior of the tank also experiences suction pressures due to the leeward suction on the tank. Wind tunnel tests have shown that the magnitude of these suctions can be very significant compared with the external wind pressures. This study has investigated the buckling resistance of a range of cylindrical steel storage tanks with primary stiffening rings subjected to non‐uniform wind loading modeled as harmonic variations, including the suction, using finite element analyses. A criterion for the required primary stiffening ring stiffness is developed, which is found to depend on its value relative to the stiffness of the cylindrical shell under each harmonic of wind loading. The effects of the shell‐ring stiffness ratio on the buckling capacity are studied and it is found to be a powerful measure that is critical to the design of the ring. Improved design rules are directly obtainable from this new treatment.
Imperfection sensitivity of unstiffened cylindrical shells under external pressure
Authors: Azizi Esmaeil , Stranghöner Natalie 
Published: September 2021

AbstractThe design rules for cylindrical shells subjected to uniform external pressure can be found in corresponding codes and recommendations, e.g. in EN 1993‐1‐6 (2007) or European Recommendation ECCS EDR5 (2008). Although the buckling strength of thin‐walled shells is highly dependent on the imperfections caused by various fabrication or manufacturing processes, the sensitivity of the buckling resistance of an imperfect shell to the amplitude of the geometric imperfections is not taken into account in design rules of standards.This paper investigates in detail the effect of boundary conditions and cylinder length on the linear buckling behaviour of cylindrical shells subjected to uniform external pressure. Following this, a comprehensive computational study is performed using geometrically nonlinear analyses on imperfect cylindrical shells with two‐imperfection types: (i) eigenmode‐affine form and (ii) longitudinal eigenmode‐affine pattern. Based on the numerical results obtained from eigenvalue analyses, the existing formulae of EN 1993‐1‐6 for the external pressure buckling factor Cβs of short cylindrical shells are modified to provide a more accurate prediction of the elastic critical circumferential buckling stress. The effects of geometric nonlinearity and imperfection sensitivity on the buckling strength are also briefly explored.
New development of design rules for girder with non‐rectangular slender web
Authors: Pourostad Vahid , Kuhlmann Ulrike 
Published: September 2021

AbstractThe current research work focuses on the analysis of longitudinally stiffened I‐girders with slender non‐rectangular web subjected to bending (M), shear (V) and M‐V interaction. Slender structures of thin panels are usually designed according to the rules in EN 1993‐1‐5 generally assuming rectangular panels. For tapered panels, the verifications in EN 1993‐1‐5, are not clearly stated.To investigate the behaviour of the non‐rectangular panels, six large tests have been realised at the laboratory at the University of Stuttgart, composed of unstiffened and longitudinally stiffened girders. The unstiffened and stiffened panels are numerically recalculated, and the model is validated. Based on a validated numerical model, a parametric study on stiffened girders has been performed. The chosen parameters cover the common application range of bridges. The results of the numerical parametric study also proved that the influence of inclined flange in respect of shear resistance may be considered advantageously. Therefore, a new resistance models has been developed, the results of the existing and the new resistance models were evaluated and compared with the numerical results from the parametric study.This paper presents an improved design approach of non‐rectangular panel considering the influence of inclined flange. The proposed approach ensures safe and more economic results for non‐rectangular panels.
Modelling issues and pushover response of singlestory older steel buildings
Authors: Cantisani Gaetano , Della Corte Gaetano 
Published: September 2021

AbstractThe paper describes a study concerning the seismic response of some typical non‐residential single‐story older steel buildings. To this end, the design of two archetype buildings was simulated according to structural codes and standards of practice used in Italy in the 1980s‐1990s. The basic structural layout was assumed to be made of trussed portals in the transverse direction and concentric braces in the longitudinal direction. In the direction of the trussed portals, two alternative structural options were considered: (a) a pinned column base with moment action provided by the truss, and (b) a semi‐continuous column base with a pinned connection between the truss and the column top cross section. 3D finite element non‐linear models of the two case study structures were built. The model included the main frame members, some critical connections and explicit representation of fracture propagation for braces. Results from non‐linear static analysis are then presented and discussed. The paper highlights differences in the structural response due to differences in the selected design options, comparing both global and local response results.
Seismic torsional effects on multi‐storey steel buildings
Authors: Ştefănescu Bogdan Cătălin , Calotescu Ileana 
Published: September 2021

AbstractDuring earthquakes, a structure may undergo torsional effects even if it is perfectly symmetrical. One of the causes is that seismic waves do not arrive in‐phase in each point of the infrastructure. Moreover, there are always eccentricities between the mass centre, where the seismic forces are considered to be acting, and the stiffness centre, around which the building rotates, this contributing as well to the occurrence of torsional effects. These eccentricities are generated by asymmetries of the structure itself, position of non‐structural elements, asymmetrically applied loading or other factors. Seismic design codes usually take into account torsional effects by means of an equivalent eccentricity that is added to the actual distance between the centres of mass and stiffness. In ordinary design, to analyse the behaviour of a structure subjected to seismic actions, when establishing the mass of the building, a fraction of the variable loads is considered to be uniformly distributed on each floor. This obviously does not happen in reality. The present paper focuses on estimating the limits of the possible actual variation of internal forces in structural members caused by torsional effects. To this aim, two eccentrically braced steel structures were considered. In each case, the variable loads were redistributed in the plan of the building according to different loading schemes, but keeping their total amount constant, equal to the value corresponding to the uniform arrangement on each floor.
Cyclic behaviour of steel beam‐to‐column joints and calculation tools
Authors: Oliveira Sara , Costa Ricardo , Rebelo Carlos , da Silva Luís Simões 
Published: September 2021

AbstractThe seismic design of dissipative beam‐to‐column steel joints is currently allowed in Eurocode EN1998 only when supported by tests due to the lack of reliable models for predicting their behaviour under cyclic conditions. On the other hand, the well‐known component method coded in EN 1993‐1‐8 (EC3‐1‐8) only applies to monotonic response of the joints. In this paper, an extension of this method, cyclic component method (CCM), is presented, which was developed and implemented for cyclic conditions in the scope of the research project EQUALJOINTS. The CCM was developed to predict the joints moment‐rotation behaviour for a wide range of joint configurations by properly combining cyclic force‐elongation behaviour of relevant components using the Modified Richard‐Abbott model. The step‐by‐step development and implementation of the CCM addresses (i) widespan variety of joint configurations and (ii) is fully compatible with the prescriptions in EC3‐1‐8. An example of application of the method is shown for an end‐plate beam‐to‐column steel beam‐to‐column joint, highlighting the level of accuracy achieved so far in the simulations of the cyclic behaviour of joints. The work performed so far shows promising results and good perspectives for new developments, which are identified making use of evidence from the results of the application example.
Seismic Performance of Steel Bridge Piers Corroded at Corners and Bottoms for Several Earthquake Motions
Authors: Kitahara Takeshi , Ohtani Yuka , Nagata Kazutoshi 
Published: September 2021

AbstractCorrosion damage on steel bridge piers has been observed at the corners where the coating tends to be thin and at the bottoms where stagnant rainwater tends to be generated. The further progress of such corrosion damage results in degradation of the seismic performance of the piers. Nevertheless, there have been very few studies on the seismic performance of steel bridge piers considering the effect of corrosion damage. In this study, the seismic response analyses by the nonlinear finite element models are carried out to investigate the seismic response behavior of the steel bridge piers with corrosion damage at the corners and bottoms. The objective of this study is to understand the influence of the corrosion damage location, corrosion damage ratio, and uncertainty in the input ground motions on the load‐carrying capacity of steel bridge piers. As a result, it is found that the maximum displacements increase and the maximum loadings decrease as corrosion damage progresses. Moreover, the change rates in the maximum displacements and maximum loadings are affected by changes in the natural periods of the target piers due to corrosion damage and by the frequency properties of the input ground motions.
Optimised Strategies for Seismic‐Resilient Self‐Centring Steel Moment Resisting Frames
Authors: Pieroni Ludovica , Elettore Elena , Freddi Fabio , Latour Massimo 
Published: September 2021

AbstractIn recent years there have been significant advancements in the definition of innovative minimal damage structures chasing the urgent requirements of more resilient societies against extreme seismic events. In this context, a type of seismic‐resilient moment resisting frames (MRFs) is based on the use of Self‐Centring Damage‐Free (SCDF) devices in column bases and beam‐to‐column joints. However, when these devices are widespread across the whole structure, the details' complexity increases significantly with respect to conventional solutions, thus limiting their practical application. To overcome this drawback, current research works are focusing on the definition of optimum locations for SCDF devices such that their effectiveness is maximised. Within this context, the present study investigates optimum locations for a limited number of SCDF devices to be used within mid‐ and high‐rise MRFs. An 8‐storey structure is selected for case study purposes and nineteen configurations are investigated considering different positions of SCDF joints. Numerical models of the selected configurations are developed in OpenSees and Incremental Dynamic Analysis are performed. The seismic responses of the case‐study structures equipped with different layouts of SCDF devices are evaluated and compared. Some considerations in terms of optimal distributions of SCDF devices are made with the aim of maximising the efficiency of the solution and the seismic performance of mid‐ and high‐rise MRFs.
Reliability assessment for the Generalized Slenderness based Resistance Method for circular and elliptical hollow sections
Authors: Beyer André , Gardner Leroy , Meng Xin , Taras Andreas 
Published: September 2021

AbstractIn the framework of the RFCS project HOLLOSSTAB, a new design method for determining the resistance of hollow section members has been developed. This method links a generalized slenderness, calculated under the effect of the combined loading, to the resistance of the cross‐section and of the member. This so‐called “Generalized Slenderness‐based Resistance Method” (GSRM) has been shown to provide accurate predictions of experimentally and numerically determined resistances of hollow sections. Nonetheless, the real benefit of this new design method could only be evaluated after a conscientiously performed reliability analysis that is presented in this paper. First, the statistical data of the input variables (cross‐section dimensions, material law) obtained through measurements are presented and compared to the assumptions of Annex E of EN 1993‐1‐1:2020. Then, the reliability analysis is outlined. In particular, attention is given to specific problems resulting from the fact that several basic parameters of GSRM have to be determined numerically (for example the critical loads under combined loading). In addition, the sensitivity of the resulting partial factors to assumptions concerning the statistical distribution of the input variables is studied and discussed.
Parametric study of stainless steel slender I‐section beams
Authors: Šorf Marek , Jandera Michal 
Published: September 2021

AbstractThe contribution shows a numerical parametric study and experimental research of welded slender stainless steel I‐section beams. Difference in behavior of stainless steel and common carbon steel members is generally known, but design of stainless steel members has been established mainly for hollow sections (CHS, SHS/RHS) as these are the typical stainless steel profiles. Currently, open stainless steel sections are also being used in structures and the design rules for both local buckling of very slender sections as well as lateral torsional buckling reduction factors are based on very limited experimental and numerical research. For this reason new research covering these phenomena was carried out at the Czech Technical University in Prague. A numerical model was used for design of test arrangement, the geometrically and materially nonlinear analysis with imperfection was made in software Abaqus. The experimental program consisted of six stainless steel beam tests being used for a model validation. The tests employed two stainless steel materials (austenitic and ferritic steel), one section slenderness (Class 4 for web and flange) and three beam slenderness. A parametric study based on the validated numerical model was carried out with the main focus on lateral‐torsional buckling of slender Class 3 and Class 4 welded I‐sections. A comparison to the existing design procedures is shown. In limited amount, resistance of Class 4 stainless steel sections in bending was also investigated.
Imperfections of LTB tests with directionally true loading using the extended Southwell‐method
Authors: Nonn Jonas , Feldmann Markus 
Published: September 2021

AbstractLateral torsional buckling tests were carried out on rolled I‐beams investigating the real effective imperfections. To this end a special test rig was developed allowing for an utmost restraint‐free, thus precise testing of statically determined beams. As a special feature the load control was such that it had to follow the occurring lateral displacement of the test objects with the use of a high‐resolution electronic control in a directionally true and force‐free manner. The imperfections were evaluated in different ways. First, by recording the geometric imperfections. Secondly, by evaluating the tests according to the Southwell‐method, which was extended for lateral torsional buckling and allows the determination of realistically uncoupled initial imperfections v0 and φ0. With the use of the imperfections, which are derived with the extended Southwell‐method (ESM), FE‐analyses lead to exact prediction of the recorded load deformation, which is shown in the paper for the example of HEA 160 sections.
Stabilizing forces in trapezoidal sheeting used as a part of the bracing system
Authors: Korcz‐Konkol Natalia , Iwicki Piotr 
Published: September 2021

AbstractIn the analysis of bracing systems imperfections of the restrained elements should be considered. According to EC3 this effect can be calculated by means of the equivalent stabilizing force, which replaces (in simplified way) initial bow imperfection of the braced element. However, alternative suggestions of the equivalent stabilizing force calculations can be also found in the literature. In this paper segment of the pitched roof with truss girders, purlins and trapezoidal sheeting was analyzed in two variants: with bar bracing and with trapezoidal cladding as a part of the bracing system (resisting in‐plane forces). The influence of the imperfections of the truss girder on the axial forces in the purlins in two cases of the bracing systems were observed. Geometrically nonlinear analysis using shell elements was performed in Abaqus. Initial imperfections of the truss girder were implemented in direct way (by importing imperfect geometry using LBA) and compare to the analytical result according to three selected methods. A few aspects that are omitted in analytical procedures were included in numerical analysis, e.g. the eccentricity between structural elements and the stiffness of selected connections. Results showed discrepancies between numerical and analytical outcomes.