bluuebunny/crossref_metadata_2025_split huggingface dataset:
08.04: Limits of plastic design for composite beams: Requirements for slim and compact composite sections
Authors: Schäfer Markus 
Published: September 2017

ABSTRACTDue to the demand for sustainable constructions, composite structures become more important and lead to slim and economic solutions. The determination of moment resistance for composite beams follows the rules for composite structures according to EN 1994‐1‐1.For the plastic design it is still assumed, that each cross‐sectional fibre can plastify without any limitation of strains. For normal composite beams in case of sagging moments and a high‐lying plastic neutral axis, the real moment resistance is slightly higher than the plastic resistance. This is based on the large strains at the bottom side of the section, so that the lower steel flange reaches the solidification range. In case of sections with a large compression zone height xpl, a concrete failure in the compression zone can happen before reaching the plastic moment resistance. In these cases a strain limit design, based on the strain‐stress relationships of concrete and steel, becomes decisive. EN 1994‐1‐1 provides only for cross‐sections of classes 1 and 2 in steel grades S420 and S460 a limitation of plastic design. It is to point out, that the rotation capacity of a composite section is not only conditioned by the b/t ratio of the steel section, but also the concrete part has a significant impact. This applies not only for high steel grades. Though, in Eurocode 4 there are no further regulations given for sections with lower steel grades. Especially, the more and more upcoming integrated and compact composite sections underline the importance of such requirements.Therefore, the objective of the recent research is concentrated on the development of additional regulations, to consider the influence of concrete compression zone height onto the moment resistance of composite beams.
08.08: Prefabricated demountable concrete and FRP decks in composite structures
Authors: Pavlović Marko , Veljković Milan 
Published: September 2017

ABSTRACTWelded shear studs are traditionally used to achieve composite actions between steel beams and concrete slabs. Relevance of composite structures for future applications in construction sector is increased by using demountable shear connectors which enables easy reuse of structures. The latest achievements of using demountable bolts embedded in prefabricated concrete slabs as shear connectors are presented in this paper. The focus of the investigation is on possible influence of execution tolerances on the level of composite action. The second issue addressed in the paper is use of Fibre Reinforced Polymer (FRP) composite deck instead of concrete slabs. FRP decks have high strength‐to‐weight ratio which reduce the total weight of the deck. Use of decks which have smaller self‐weight facilitates the transport and execution process and reduces foundation costs especially in high‐rise buildings. FRP composites are used in aerospace, automotive and shipbuilding industries for decades. They are considered as a maintenance free material. The main obstacle for wider applications of FRP material in construction is relatively a low stiffness of composites made of glass fibres and thermoset resins. Use of sandwich systems and hybrid decks, which combine FRP and the steel to increase the stiffness, are investigated in order to satisfy the design requirements. The third item of modern composite structures considered in this paper is use of high strength steel (HSS) grades to optimize the weight/strength ratio of structures. Results of a short parametric study using welded hybrid beams, combination of HSS and mild steel grades, is presented. This indicates significant reduction of weight and costs compared to the design using rolled cross section beams.
08.11: The SMARTCOCO project: A research push for hybrid structures
Authors: Plumier André , Degée Hervé 
Published: September 2017

ABSTRACTThe SMARTCOCO research project was developed to fill gaps in knowledge and provide design guidance for specific types of composite steel concrete structural elements used in high rise or heavily loaded structures. The targeted elements are composite columns reinforced by several fully encased steel sections, columns of reinforced concrete buildings reinforced by one steel section over the height of one storey, without continuity above and under that storey and concrete flat slabs or beams connected to columns or walls by means of steel shear keys. Those composite elements belong to structures defined as “hybrid” because they are neither reinforced concrete structures covered by Eurocode 2, nor composite steel concrete structures covered by Eurocode 4. Gaps in knowledge are mostly related to the way to evaluate the force transmission between concrete and embedded steel profiles and to design the components to resist those forces. A generic design approach based on the logics of composite sections and of reinforced concrete sections, like equivalent sections and struts and ties mechanisms, was first developed and used to design test specimens. These ones were tested in physical and/or numerical experimentations. The results were used to calibrate or correct the initial proposal for design. The output is written as a design guide which intends to complement Eurocode 2 and 4.
08.20: Experimental verification of composite action using push‐out tests
Authors: Kvočák Vincent , Dubecký Daniel , Kožlejová Viktória 
Published: September 2017

ABSTRACTOne of the common types of steel‐concrete composites is the filler‐beam deck bridge with encased steel beams. Steel beams form rigid reinforcement in a longitudinal direction, while such decks are reinforced with secondary cross‐wise reinforcement in a transverse direction. Composite action between the steel and concrete sections is ensured by means of concrete stud connectors. In comparison with the composite action provided traditionally by shear stud connectors, this type of action has higher load‐bearing capacity and fatigue strength, and it is not so labour‐intensive. Great attention is paid to the development of perforated steel strips today. These are employed mainly for the achievement of composite action between a steel beam and concrete slab. To date, a variety of types of composite action have been investigated at the Civil Engineering Faculty of the Technical University of Košice; therefore, the article presented shows some of the test results from push‐out tests performed on various specimens.
08.27: Steel‐timber composite (STC) beams: Numerical simulation of long‐term behaviour
Authors: Chiniforush Alireza A. , Valipour Hamid , Akbarnezhad Ali , Bradford Mark 
Published: September 2017

ABSTRACTConventional steel‐concrete composite floors comprising of steel sections and sheeting, cast in situ concrete and embedded stud shear connectors are made from energy‐ and carbon‐intensive construction materials, viz. concrete and steel. Replacing conventional reinforced concrete floors with solid timber, in particular cross‐laminated timber (CLT) with improved stability and structural characteristics, can significantly increase the speed of construction, reduce the need for rigging and craneage and also lower the self‐weight of the building, the size of the columns and foundations and therefore the overall carbon footprint of the building. However, experimental data on the short‐ and long‐term structural performance of steel‐timber composite (STC) floors under service loading conditions are scarce and no long‐term theoretical analyses of steel‐timber composite floors have been reported hitherto in the literature. Accordingly, non‐linear 1‐D frame finite element models are developed in this paper, and validated against experimental data on timber and hybrid timber composite beams. The numerical tool is then employed to predict the long‐term stiffness and load‐deflection response of STC floors under service loading conditions. A parametric study is carried out and the influence of the stiffness of the shear connectors, timber shrinkage, creep, hydro‐expansion and mechano‐sorptive effect on the long‐term behaviour of the STC beams are investigated.
08.33: Full scale test on steel‐concrete composite beams: Investigation of innovative shear connectors
Authors: Kovács Nauzika , Kövesdi Balázs , Kachichian Mansour , Frank Máté Ferenc 
Published: September 2017

ABSTRACTFull scale tests on eight steel‐concrete composite beams have been executed in the Structural Laboratory of the Department of Structural Engineering, Budapest University of Technology and Economics in Hungary. The aim of the test series was to investigate the structural behavior of the new and innovative shear connections applied at the steel‐concrete interface. During the test the beams have been simple supported and tested under three point bending until the final failure following the Eurocode recommended testing procedure. The composite beams are built up of IPE 400 steel beams and 20×50 cm RC slab. The length of the beams was 6 m for each. The general layout and material grade of each beams are identical, however each has special shear connection: headed studs (as reference), perfobond plates, Y‐shaped perfobond, dove tale perfobond plates, trapezoidal perfobond plates. These connection types have been already tested by push‐out test in the same Laboratory in the previous years.The main goal of the full scale tests was to investigate the force‐slip relationship for each connection types and verify the results of the push‐out tests. To determine the structural behavior of the shear connection both tests have been evaluated: the shear resistance of the connection is determined by the push‐out test and the initial stiffness by the beam tests. Further aims are to develop a test based calculation model for the design of the new innovative shear connections, and to build and verify and advanced FE model to perform virtual test on further connection configurations.
08.36: Numerical modelling of circular CFST members and assessment of multi‐axial stress state effects
Authors: Jiang Yadong , Kalemi Bledar , Silva António , Castro José Miguel , Monteiro Ricardo 
Published: September 2017

ABSTRACTMulti‐axial stress states, namely the concrete confinement effect and the bi‐axial stress state that develops on the steel profile, have a significant influence on the flexural behaviour of the circular Concrete‐Filled Steel Tubular (CFST) members. The results from an experimental investigation carried out at the University of Porto indicated that the combination of the two multi‐axial stress states contributes to an increase of the flexural capacity of circular CFST members. This paper presents the development of a 3D model in ABAQUS that has been validated against experimental data. A distributed plasticity model is also developed in OpenSees. It is shown that the 3D model, contrary to the distributed plasticity model, is able to simulate the multi‐axial stress states, hence reproducing the bending behaviour of circular CFSTs with fairly good accuracy. An extensive parametric study involving different CFST members is conducted with the aim of characterizing the concrete confinement effects as well as the bi‐axial stress states developing in the steel tube. A large database of results was generated and then employed in the derivation of modified uniaxial material strength properties. Relationships between the corrected material strength and the cross‐section factor, ζ, which depends on the cross‐section properties of the member, for both concrete and steel section, were derived as closed‐form expressions. These properties can be adopted both for cross‐section analysis and for the development of simplified distributed plasticity models. The accuracy of the distributed plasticity model was improved when the strength correction equations were applied.
08.44: Elastic buckling behavior of the surface material in sandwich structure
Authors: Yamanaka Moe , Ikarashi Kikuo , Inaba Toru 
Published: September 2017

ABSTRACTA sandwich structure manufactured using a thin plate is lightweight, but has high bending stiffness. It is a very ideal structure from an environmental and structural point of view. It is very important to understand the buckling behavior of the surface material in this structure. Many arguments about it are based on in‐plane compression and in‐plane pure shear. When a steel sandwich panel is used on a roof or a wall, it is assumed that out‐of‐plane bending occurs owing to wind pressure and gravity. The purpose of this study is to understand the tendency of elastic buckling strength of the steel sandwich panel under out‐of‐plane bending and evaluate it using a simple formula.The following conclusions are obtained: (1) Select assumptions that are considered the most appropriate for calculating the elastic buckling strength of the steel sandwich panel under out‐of‐plane bending. The theory proposed by Plantema corresponds well to the finite element analysis in scope of this study. (2) Calculate the elastic buckling strength of the steel sandwich panel under out‐of‐plane bending by the method expanded the theory proposed by Plantema. It converges to a constant value when the range of the thickness of the core material is large, and increases when this range is small. (3) Evaluate the elastic buckling strength of the steel sandwich panel under out‐of‐plane bending, and propose a simple approximation formula including the previous one.
08.51: An experimental study of composite beam‐column joints subject to impact loads
Authors: Chen Kang , Tan Kang Hai , Yang Bo 
Published: September 2017

ABSTRACTBeam‐column joints are one of the key elements in steel and composite frames. Till now, many research studies have focused on the behaviour of bare steel beam‐column joints and the influence of composite slabs subjected to quasi‐static loads. In this study, the research was extended to dynamic loading condition. Two beam‐column joint specimens with composite slabs, which were designed based on Eurocode 4, were tested using an MTS drop‐weight machine. This loading condition is probably more realistic for joints under progressive collapse scenario, which is a dynamic process. One of the specimens was a middle joint subject to sagging moment. The other specimen was a side joint subject to hogging moment. Behaviour of both joint specimens, including impact force, displacement of the middle column, strain and failure mode, was presented. Differences in the behaviour of the two joint specimens were observed and explained.
08.54: Behaviour of steel‐timber beam in bending
Authors: JURKIEWIEZ Bruno , DURIF Sebastien , BOUCHAIR Abdelhamid 
Published: September 2017

ABSTRACTThe combination of timber elements and steel beams can be of high interest for fire protection and mechanical performances including the elastic instabilities. In this paper, experiments are performed to analyse the behaviour of various configurations of steel‐timber beams in bending. Each steel beam is connected to two timber beams at the web and the flanges. In order to define the material properties of the tested elements, each component (wood and steel) has been tested independently in the elastic field. Then, the timber and steel beams have been connected and tested until the failure. The observed behaviour show a significant effect of the reinforcement provided by the timber beams. In fact, the combination of timber‐steel elements improves the resistance to lateral buckling and local buckling of the steel profile.This preliminary study, based on an experimental approach, is used to evaluate the performances of different means of connection and to define the possibilities of the combination of timber and steel elements for further developments.
08.60: Composite dowels in cracked concrete Experimental investigation
Authors: Classen Martin , Christou Georgios , Hegger Josef 
Published: September 2017

ABSTRACTIn steel‐concrete composite girders, composite dowel shear connectors can be used to transfer shear forces between the concrete slab and the steel section. In comparison to other shear connectors the composite dowels offer increased strength capabilities, higher deformation capacities both in normal and in high strength concrete and offer an efficient use of steel and concrete. Composite dowels gain increasingly acceptance and are more and more used especially for prefabricated constructions. In regions with negative bending moment – for example near the interior supports of continuous composite beams, where concrete cracking occurs, the shear capacity of composite dowels may be affected by transverse concrete cracks. So far, the internal shear carrying mechanisms of composite dowels in cracked concrete are not clarified and existing shear capacity models do not account for concrete cracking. Hence, the present paper summarizes the results of 38 shear tests, providing novel insights regarding the pry‐out failure of composite dowels in cracked concrete. The tests were performed in an innovative test setup, whereby concrete was cracked prior to the test allowing to investigate the impact of crack spacing and crack width.
09.17: Fatigue life of marked steel components
Authors: Jungbluth Dominik , Stranghöner Natalie 
Published: September 2017

ABSTRACTSteel components have to be identifiable and traceable during the whole manufacturing chain. The choice of the identification method is not specified consistently in international rules and standards. The European standard for the execution of steel structures EN 1090‐2 specifies that the use of durable marks may not result in producing damages without saying which damages are meant. Hard stamped marks are only permitted for steel grades up to S355 and only in areas where no effect on the fatigue life is expected. Otherwise the use of soft stamps should be verified. In other international standards hard stamped marks are explicitly required. These contradictions should be resolved.In terms of durability and liability, markings should be resistant against particular manufacturing processes such as sandblasting, hot‐dip galvanizing or coating. For this reason, the following marking methods are used in practical applications: hard stamping, scribing, plasma marking and needling.Nowadays the machinery manufacturers have developed machines in which the marking process can be automatically integrated in the manufacturing process of steel components so that manual layout scribing is not required anymore and components can be marked on the fly. However, the effect of the installed notch due to the marking process on the fatigue strength of the components has not been investigated yet. As a result, a classification of the resulting notched details according to the European detail categories of EN 1993‐1‐9 is in principle not possible.For these reasons, the influence of durable marking methods on the fatigue strength of steel components needs to be clarified by experimental fatigue tests and numerical calculations which have been performed at the Institute for Metal and Lightweight Structures of the University of Duisburg‐Essen. Within these investigations the different marking methods hard stamped, scribed, plasma marked and needled as well as unmarked structural details have been examined. The experimental investigations have been carried out considering three different steel plate thicknesses 15 mm, 25 mm and 40 mm and two different steel grades S355J2 and S460N.As expected the marked specimens show a decrease of the loading cycles until failure even though there are differences in fatigue life due to the different markings and their characteristic notch geometries.
10.23: Parametric study on the fire resistance of steel columns with thermal gradients
Authors: Correia António Moura , Rodrigues João Paulo , Kodur Venkatesh , Correia José Pedro 
Published: September 2017

ABSTRACTThe current design Codes for steel columns under fire situation, are based on the assumption that the temperature distribution is uniform, and thermal gradients are neglected. However, nowadays this assumption is very rough, since several studies have been conducted in recent years, and the thermal gradients along the web or along the flange are quite well quantified, for cases with the column oriented with the web perpendicular or parallel to the adjacent walls.The main issue to be discovered is whether in any case, the columns fail sooner during a fire event being only partially heated, than the columns totally engulfed in fire. This eventual behaviour may be provoked by the thermal bowing phenomenon. This is the purpose of this study. To find out in which cases, if any, the walls play a detrimental role in the fire resistance of the columns, a set of numerical simulations were carried out. A geometrical and material non‐linear analysis was performed, to assess the real influence of the surrounding walls on the fire behaviour of steel columns.Moreover, the mechanism of failure can also be very different in steel columns embedded on walls, than the one observed in columns totally engulfed in fire. The post‐buckling behaviour of the column is of extreme importance in terms of global failure of a structure. This is also a very important issue analysed in the present study.The main conclusion of this work, intend to ascertain for different values of slenderness and load levels, if in any case, the walls presented a detrimental role, meaning that the fire resistance of the column was lower in the case it was in contact with walls.
11.26: The seismic design of a building having a dual type structural system in Romania
Authors: Vlad Ion , Vlad Mirela Nausica 
Published: September 2017

ABSTRACTThe March 4, 1977 earthquake was the last major seismic event that struck Romania. 1,600 persons were killed, over 11,000 were injured, and 33,000 buildings collapsed or were severely damaged. The great majority of these injuries were in masonry and reinforced concrete buildings. The few existing steel structures behaved very well during the earthquake, excepting the situation when inadequate structural concepts were met. Even if the number of steel buildings was not so high, steel was used especially for long span roofs of industrial buildings. Starting with that period, the design practice proved that steel is an excellent material for seismic‐resistant structures thanks to its performance in terms of strength and ductility. The bulk of the paper consists in presenting the design of a dual type structural system having in the horizontal plane the shape of the letter “Y” and in the vertical plane two basements, a ground floor and 14 stories. Trying to realize a building virtually immune to earthquake action the superstructure of the building, of composite type, was conceived to have two different parts: (a) a reinforced concrete structural subsystem formed by the three structural cores placed in the peaks of the equilateral triangle, their main role being that of assuring the lateral strength of the building to the seismic loads; (b) a steel structural subsystem, having a structural role mainly towards the gravity loads. The steel structural subsystem is placed in the central zone of the building and is connected to the three reinforced concrete cores placed in the peaks of the equilateral triangle. It consists of three moment resisting frames and composite type floor structures. The paper also contains information about the results of some in‐situ dynamic investigations performed after each stage during the construction, in order to validate the structural models of analysis and the contribution of the steel structural subsystem on the overall dynamic characteristics of the building.