bluuebunny/crossref_metadata_2025_split huggingface dataset:
11.16: Seismic performance evaluation of MRFS with dissipative continuous columns
Authors: Yan‐wen Li , Guo‐qiang Li , Fei‐fei Sun 
Published: September 2017

ABSTRACTThe Dissipative Continuous Column (DCC) concept is proposed as a gravity load and seismic energy dissipating dual‐functional structural component. The proposed DCC is made up of two closely spaced continuous columns which are interconnected with replaceable steel strip dampers (RSSDs) over the height. It works in a way similar to pin supported coupled shear walls, but minimizes the construction invasive and ensure rapid return to occupancy after severe earthquakes. The innovative moment resisting frame (MRF) system with DCCs can also mitigate the inter‐storey drift concentration and reduce the soft storey failure risk significantly due to the contribution of large flexure stiffness of the DCCs. Based on the experimental test results, a simplified analysis model of the DCCs is developed for the design and seismic performance evaluation of the MRFs system with DCCs. The simplified analysis model consists of dual column and multiple zerolength equivalent elasto‐plastic springs with rigid end. Numerical models of a 4‐story conventional steel MRF and a 4‐story steel MRF with DCCs were set up using the proposed simplified model. Nonlinear Dynamic Time History Analysis were undertaken, and the results showed that the MRFs with DCCs can reduce the economic loss by limiting the structural damage in the replaceable steel strip dampers and mitigating both the maximum inter‐story drift ratio and drift concentrations.
11.23: Influence of the uniaxial material model of steel on the seismic response of steel structures
Authors: Bosco Melina , Ghersi Aurelio , Marino Edoardo M. , Rossi Pier Paolo 
Published: September 2017

ABSTRACTThe model proposed by Menegotto and Pinto [1] is widely used to simulate the dynamic response of steel structures and steel bars of reinforced concrete structures. In 1983, Filippou et al. [2] highlighted a flaw in the original formulation of this material model. They observed that, if partial unloading takes place at strains lower than the maximum recorded value, the reloading path provides forces that are higher than those expected. Filippou et al. deemed that such errors were not particularly significant for reinforced concrete members and did not propose any modification to the analytical formulation of the model.More recently, some authors have independently investigated this issue and highlighted that the above‐mentioned flaw may affect the prediction of the seismic response of steel structures. Thus, some modifications have been proposed [3–5] and implemented in OpenSees computer program.In this study, the seismic response of a steel moment resisting frame and that of a braced frame are analysed by nonlinear dynamic analysis by means of the OpenSees program. For each structure, the stress–strain relationship of steel is separately modelled by means of the original formulation of the model by Menegotto and Pinto and by the modified versions proposed by Zsarnóczay and Budaházy [3], Kolozvari et al. [4] and Bosco et al. [5]. The seismic response predicted by the considered models is compared. Attention is focused on the moment–curvature time‐history at the ends of the members of the framed structure and on the axial force‐axial deformation time‐history of braces. Global response parameters are also considered in terms of the maximum storey drifts.
11.33: Performance evaluation of an innovative HCW system with Shear Dissipative Links
Authors: Das Rajarshi , Zona Alessandro , Vandoren Bram , Degée Hervé 
Published: September 2017

ABSTRACTThis paper presents an improved approach to a newly suggested design procedure of an innovative Hybrid Coupled Wall (HCW) system. This system consists of a reinforced concrete (RC) shear wall with dissipative steel links and steel side columns, where the RC wall carries almost all the horizontal shear force while the overturning moments are partially resisted by an axial compression‐tension couple developed by the two side steel columns rather than by the individual flexural action of the wall alone. The design objective is to reduce or possibly avoid the damage in the RC wall while concentrating the seismic damage to the replaceable steel links which are shear critical, i.e. intended to fail in shear rather than flexure. This increases the energy dissipation ability of the whole system and thus improves its resistance towards seismic ground motion. This present piece of investigation also aims to bring clarity to some important points such as: definition of an efficient coupling ratio with or without uniform link distribution, lower and upper limits of the coupling ratio compatible with the assumed link distributions, relationship between the coupling ratio and the total building height. The proposed design procedure is applied to case studies considering various assumptions for the design parameters. The designed solutions are analysed through several nonlinear finite element models in order to evaluate the results of the design methodology and provide useful information on the ductility capacity of the proposed innovative HCW system for different coupling ratios and efficient energy dissipation characteristics of the shear links.
11.37: Hybrid tests of a full‐scale two‐story buckling‐restrained braced RC frame
Authors: Wu An‐Chien , Tsai Keh‐Chyuan 
Published: September 2017

ABSTRACTA novel implementation of buckling‐restrained braces (BRB) in new reinforced concrete (RC) frame construction is investigated. Seismic design and analysis methods for the use of the proposed steel cast‐in anchor bracket (CAB) as the connection for the BRB and RC members are investigated. The steel CAB is designed to resist the normal and shear forces transferred from the BRB in order to secure the seismic performance of RC buildings. In this study, a full‐scale two‐story RC frame with BRBs (BRB‐RCF) is tested using hybrid and cyclic loading test procedures. The BRBs are arranged in a zigzag configuration and designed to resist 70% of the story shear. The gusset design incorporates the BRB axial and RC frame actions, while the beam and column members comply with ACI 318‐14 seismic design provisions. When the inter‐story drift ratio for both stories reached 3.5%, the overall lateral force versus deformation response was still very stable. The hysteresis energy dissipation ratios in the four hybrid tests range from 60% to 94% in the two stories, indicating that BRBs can effectively dissipate seismic input energy. Test results confirm that BRBs enhanced the RC frame stiffness, strength and ductility, complied with performance‐based seismic design. No failure of the proposed steel CABs and RC discontinuity regions was observed in the tests. This study demonstrates that the proposed design and construction methods for the CABs are effective and practical for real applications.
11.43: Seismic performance of staggered steel plate shear wall systems in high rise buildings
Authors: Verma Abhishek , Sahoo Dipti Ranjan 
Published: September 2017

ABSTRACTUnstiffened Steel Plate Shear Walls (SPSWs) are used as the lateral load‐resisting systems in building structures. The energy dissipation mechanism of SPSWs is consisted of the tension yielding of web plates and the formation of plastic hinges at the ends of horizontal boundary elements (HBEs). High‐rise buildings experience the high overturning moments leading to the high axial demands in the vertical boundary elements (VBEs) of SPSWs. The presence of high axial forces in VBEs can cause a reduction in their flexural capacity resulting in the drift concentration or even soft‐story mechanisms in the lower storey levels during an earthquake event. Past studies have shown that a staggered arrangement of steel plates may help in reducing the force demand in VBEs. Two simple methods are investigated in this study to r b educe the VBE forces are (i) by increasing the width of the web plates and (ii) by staggering the web plates over the frame height. A 20‐story steel frame building has been considered as the study frame. Three types of systems are designed to study the effect of aspect ratio and staggering on the seismic behaviour of SPSW. Force‐displacement characteristic of SPSW used in the numerical model is validated with the test results. Both nonlinear static and dynamic analyses are carried out in this study. Axial and shear force demands in the VBEs are reduced for the study frame, while achieving the desired hinge mechanisms. Nonlinear dynamic analyses under twenty spectrum‐compatible design‐level ground motions exhibited that staggered steel plate shear wall systems reduced the inter‐story drift by about 50% with respect to their conventional counterpart.
I.11.68: Seismic behaviour of concentrically braced frames in the moderate seismicity context
Authors: Kanyilmaz A. , Castiglioni C.A. , Degée H. 
Published: September 2017

ABSTRACTThere has been a large amount of research investigating the performance of concentrically braced frame (CBF) structures in the high‐seismicity regions. Indeed, most building codes are appropriately advanced for the design of these structures in the high seismicity context. However, although CBFs represent a very common structural solution in the low‐to‐moderate seismic regions, there is not enough experience and experimental evidence showing their performance in such context. Within the European research project MEAKADO (RFSR‐CT‐2013‐00022), this subject has been investigated deeply by means of experimental and numerical activities. The objective of the MEAKADO was to study an intermediate way of design to reach a sufficient safety by means of a reduced but controlled amount of ductility in the structural system. This article summarized the results of the full‐scale tests conducted within MEAKADO, which investigated the behavior of CBFs in the low‐to‐moderate seismicity context. Tests focused on the secondary frame action, contribution of the compression diagonal in X‐braced frames and ductility provided by standard bolted bracing connections.
12.11: Experimental and numerical studies on Q690D welded Box‐section columns under cyclic loading
Authors: Suwen CHEN , Xing CHEN , Yan‐Bo WANG , Zhili LU , Guo‐qiang LI 
Published: September 2017

ABSTRACTTo evaluate hysteretic performance of Q690D high‐strength steel (HHS) welded box‐section columns, cyclic tests and numerical studies have been carried out. Firstly, cyclic loading tests were performed on two box‐section Q690D HSS welded columns with nominal axial compression ratio of 0.35. Failure modes were observed as elastic‐plastic local buckling of plate. The hysteretic curves and skeleton curves of the test specimens were produced and show that the tested columns have good energy dissipation capacity. It also shows that second order effect cannot be neglected for HHS welded columns. Then a finite element model has been built to simulate the cyclic loading tests. Comparison of numerical and test results verified the effectiveness of the built numerical model, which can then be used for further parametric analysis.
12.16: Numerical investigation of the local buckling behaviour of high strength steel circular hollow sections
Authors: Toffolon Andrea , Taras Andreas 
Published: September 2017

ABSTRACTThe introduction of high‐strength steel (HSS) hollow sections with yield strengths of fy=690 MPa and beyond in the construction sector is currently made more difficult by a lack of knowledge on the specific local and local+global buckling behaviour of slender HSS cylindrical hollow‐sections. With rising yield strength, buckling phenomena become more relevant. Eurocode 3 design provisions classify CHS as “slender \ class 4” at a diameter to thickness ratio of D\t=90·∊2, with ∊2=235\fy. For HSS with fy=690 MPa and beyond, the majority of cold‐formed and many hot‐finished CHS will be class 4 and should be designed accordingly. However, no straightforward rules for the design of class 4 HSS CHS are found in EC3. This paper discusses initial numerical studies on the specific local buckling behavior of HSS CHS sections. The study represents the initial steps in the recently initiated RFCS research project “HOLLOSSTAB”, during which new design rules for HSS hollow sections are developed on the basis of an “Overall Interaction Concept” (OIC). This concept – similarly to the Direct Strength Method (DSM) used in North America for the design of cold‐formed steel open cross‐sections – makes use of the results of (numerical) linear buckling analyses (LBA) for the whole member to determine the slenderness and consequently an “overall” buckling reduction factor. The paper discusses how this approach fits into the general framework of buckling design checks for cylindrical structures, discusses existing rules and their implications for HSS CHS, shows numerical results and introduces initial design proposals based on the OIC approach.
12.21: Cyclic loading in stainless steel links under lateral loads
Authors: Chacón Rolando , Arrayago Itsaso , Mirambell Enrique , Real Esther 
Published: September 2017

ABSTRACTLink elements are dissipative devices in form of beam segments that are typically included in eccentrically braced frames (EBF) subjected to lateral loads and seismic hazard. Studies related to short links, energy dissipation and plastic hinge formation have been presented for carbon steel elements with several conclusions at material, member and structural levels.Stainless steel is a nonlinear metallic material with particular appeal for its structural use due to a considerable amount of capabilities such as corrosion resistance, circular life‐cycle, sustainability, strength, ductility and aesthetics. Despite the increase of the use of stainless steel for structural elements in construction, the behaviour of this material for structural purposes is not defined accurately as the carbon steel in all applications. The most important difference between these types of steel is the shape of the stress‐strain curve. Whereas carbon steel typically exhibits linear elastic behaviour up to the yield stress and a plateau before strain hardening is encountered, stainless steel has a more rounded response with no well‐defined yield stress, leading to a non‐linear material behaviour.The elastic stiffness, maximum load, shear deformation capacity as well as the energy dissipation in short links are generally affected by the defined geometrical parameters such as link length, web stiffening and connectivity. Due to the material nonlinearity of stainless steel, this influence may be considerably affected by the stress‐strain curve and its corresponding energy dissipation since a nonlinear kinematic hardening branch must be adequately provided in numerical simulations for the sake of accurately reproducing the cyclic behaviour.In this paper, a numerical model aimed at studying the cyclic behaviour of short stainless steel links subjected to seismic lateral loads is presented. The model accounts for the material and the geometrical nonlinearities. Several geometrical as well as material configurations (length, web stiffening and constitutive equations) are studied. The results and conclusions obtained in this research are used for a subsequent definition of a research program related to stainless steel frames subjected to seismic loading including several structural configurations in both concentrically (CBF) and eccentrically (EBF) braced frames assembled with plastic or slender members.
12.22: Seismic performance of high capacity hybrid beam‐columns: Comprising of high strength steel tubes subjected to lateral cyclic loading
Authors: Javidan Fatemeh , Heidarpour Amin , Zhao Xiao‐Ling , Al‐Mahaidi Riadh 
Published: September 2017

ABSTRACTHigh strength and ultra‐high strength materials are widely used in industrial applications significantly increasing the load bearing capacity and reducing the overall weight and cost. The present study continues a series of experimental investigations on innovative fabricated hybrid sections consisting of high strength steel tubes welded to mild steel plates. This type of innovative section is proposed with the aim of promoting the application of high and ultra‐high tensile steel in construction, taking advantage of the load‐bearing capacity of these materials along with the coupled effect of ductile mild steel plates. Large‐scale hybrid columns are tested under a combination of axial load and lateral cyclic load using a multi‐axis substructure testing (MAST) facility. Lateral cyclic loadings are applied along with constant axial loads of which the hysteretic curves are obtained for various grades of steel tubes, namely, mild steel tube (grade 300), high strength steel tube (grade 800) and ultra‐high strength steel tube (grade1200). Test results are analysed to examine the seismic performance of these proposed innovative sections and obtain the combined axial and lateral cyclic capacities, drifts, strains and plastic hinge distributions along the beam‐columns. The effect of tube material is considered and the axial shortening observations are compared to constant compression. The experimental outcomes of this paper can be incorporated in nonlinear modelling of structures consisting of ultra‐high strength steel tubes.
13.02: Safety assessment across modes driven by plasticity, stability and fracture
Authors: da Silva Luís Simões , Tankova Trayana , Marques Liliana , Kuhlmann Ulrike , Kleiner Andreas , Spiegler Jennifer , Snijder H.H. , Dekker Rianne , Taras Andreas , Popa Nicoleta 
Published: September 2017

ABSTRACTThe European design rules for steel structures in EN1993 cover various failure modes that were developed using different methodologies in terms of accuracy and safety. Consequently, the safety level of these design rules is not homogeneous throughout their own field of application, as well as in comparison between different rules. Safety is regulated by partial factors for the various loads and resistances, respectively. EN 1990 – Annex D offers a procedure for the reliability assessment of resistance functions, based on a semi‐probabilistic approach. However, its application is not straightforward in many cases concerning steel design rules and several additional assumptions are necessary to ensure that a target probability failure is achieved. Moreover, the design rules are calibrated using certain variability values for the relevant parameters, such as material properties, geometric properties and imperfections. It is therefore required to appropriately characterize the statistical distributions of these basic variables in order to comply with the safety assessment procedure. The present research work, carried out in the context of the European research project SAFEBRICTILE, had as a main objective the harmonization of the reliability level of design rules for steel structures covering modes driven by ductility, stability and fracture.This paper gives an overview of the reliability assessment of the Eurocode design rules carried out within the project for the studied failure modes; presents the adjustments in these design rules proposed whenever it was necessary; it also transmits the project recommendation on the statistical distributions of the relevant basic variables for steel structures, summarized in the “European database of steel properties” that was also developed within the project framework.
13.04: The next generation of Eurocode 4
Authors: Banfi Mike 
Published: September 2017

ABSTRACTWork is under way on the next generation of Eurocodes. These will build on the work done by the original authors and seek to enhance the ease of use of the code as well as include revisions requested by users and resulting from research work over the last ten to twenty years. In addition there is an ambition to reduce the number of Nationally Determined Parameters as some relate to the lack of a consensus at the time of the initial drafting of the codes rather than aspects of the code e.g. safety factors that remain the prerogative of the Member States. Eurocode 4 has been well received but improvements can always be made. The systematic review process has highlighted areas where users want clarification or change. Project teams have also been set up to look at three specific aspects of the code. In addition as Eurocode 4 relies on Eurocode 2 and Eurocode 3 an improvement in the harmonisation between the three codes has been requested. This paper sets out the main areas which are being considered during the revision process. Throughout the process the need to balance the benefit of any changes against the disruption that this will make to existing users has been considered.
15.09: High‐resolution modelling and design of steel structures
Authors: Surampudi Bala A.V. , Butler Martin A , Swanson James A , Rassati Gian Andrea 
Published: September 2017

ABSTRACTThe art and science of structural engineering has always required a balance between predicting the demands on a structure and making sure that those demands can be met with the structure's strength and stiffness. Historically, analytical models have been used to predict demands and codified design equations have been used to predict strength. Over the past approximately 50 to 60 years, finite element analytical models have evolved from crude first‐order linear representations made up of dozens of degrees of freedom to sophisticated second‐order nonlinear models made up of hundreds of thousands of elements. With the ever increasing capability of personal computing and the ability to construct more and more sophisticated finite element models, new approaches to the design of steel structures that were once thought impossible are becoming realistic.State of the art a decade ago was to employ models constructed from discrete one‐dimensional elements based on nominal geometry and linear material behaviour. Influences and behaviours such as residual stresses, initial imperfections, buckling, fracture, and second‐order effects were addressed by codified design specifications, often in the form of tedious hand calculations. Exponential increases in computing power now permit entire structures to be represented using shell or solid elements and explicit modelling of influences such as residual stresses and initial imperfections. As a result, the balance between analysis and design can change. With modern sophisticated computer analyses, the balance can be shifted towards the analysis side of the equation leaving less work in the strength determination. With a model like the one described above, strength could be defined simply as yielding or as the development of a numerical singularity resulting from a loss of stiffness representing buckling or fracture.This paper outlines ongoing work towards developing guidelines for high‐resolution computer modelling of steel structures and rebalancing the treatment of phenomena between the analysis side and the design side of the equation.