bluuebunny/crossref_metadata_2025_split huggingface dataset:
08.40: Numerical investigation of mechanical properties of multi‐planar concrete‐filled steel tubular joints
Authors: Chen Juan , Nie Jianguo , Zhou Chengye 
Published: September 2017

ABSTRACTWith the development of large span and heavy load modern engineering, concrete‐filled steel tubular structures appear constantly. The joints of these structures are mostly multi‐planar joints. In order to solve the problem of lacking of the investigation of multi‐planar concrete‐filled steel tubular (CFST) joints, the mechanical behaviour of CFST KK joints were studied through refined finite element simulation. Accurate finite element models of CFST KK joints were established by considering the material nonlinearity, the geometry nonlinearity, and the contact nonlinearity between the tube and the concrete. The spatial effect of multi‐planar joints was be obtained by comparing with planar joints. The FEA results showed that, the multi‐planar carry‐over effects had the maximum effect for the 60° CFST joints, the strength of multi‐planar joints decreased compared with the planar joints, and the stiffness of them did not vary substantially. While for the 90° CFST joints, both the strength and stiffness of multi‐planar joints did not vary substantially with the planar joints. This research can provide scientific basis for the design of multi‐planar CFST joints, and effectively promote the application of CFST structures.
08.42: Composite behaviour of headed stud shear connectors with BubbleDeck flooring
Authors: Denoord Luke , Varsani Harshad , Tan Ee Loon , Singh Balbir 
Published: September 2017

ABSTRACTBubbleDeck is a biaxial voided concrete slab product that was developed in the 1990's by Danish engineer Jorgen Breuning. The technology is similar to other modern voided slabs such as U‐Boot and Cobiax, however it has its distinct advantages. These advantages include decreased construction time, material costs savings and the environmental benefits. Composite steel‐concrete construction is an increasingly common construction method in the modern building industry. This process involves utilising the high tensile strength of steel and the high compressive strength of concrete to create composite members with structurally favourable characteristics. In order to join the steel and concrete components, a connection is needed to stop slip occurring at the interface and allow the materials to behave as a single element. The most common connection is the end welded headed shear connector, known more commonly as the shear stud. Shear studs have a recommended design capacity as specified by suppliers and connections are designed according to these capacities. Standards such as Eurocode and Australian Standards have a guide for composite connection design; however, these guides do not pander to new technologies such as BubbleDeck. As such engineers and designers often have difficulty and uncertainty in designing these types of connections. Through analysis of composite connections and BubbleDeck specifications, a series of test specimens has been designed. Specimens were composed of concrete, steel reinforcement, a steel section, shear studs and BubbleDeck void formers. These specimens were tested according to the Eurocode 4 standard to study the interactions of the BubbleDeck voids and the headed shear connectors. Experimental results and observations were recorded during and after the test specimens were tested. Results suggested that the overall shear capacity or BubbleDeck slabs in composite beams was approximately 5 to 10 % less than the capacity of equivalent solid slabs. The observations showed that the proximity of headed shear connectors to voids did not have a significant effect on the capacity of the connection, with respect to the arrangements tested.
08.49: Comparison of headed studs with perfobond shear connectors – experimental and numerical analysis
Authors: Spremić Milan , Gluhović Nina , Marković Zlatko , Dobrić Jelena , Filipović Aljosa 
Published: September 2017

ABSTRACTDifferent types of shear connectors which assure composite action between steel profile and concrete slabs have been developed during decades, considering different shapes, installation equipment and installation process. Also, three main characteristics of shear connectors, shear resistance, stiffness and ductility are specific for each type of shear connector. Widely used shear connectors for composite constructions of buildings and bridges are headed studs and different types of perfobond shear connectors. Different behaviour of these types of shear connectors, mainly reflected in unsatisfactory behaviour of headed studs resulted from fatigue problems, reflects in their various applications. Numerous experimental and numerical investigations performed with headed studs and perfobond shear connectors through standard push‐out tests resulted in development of design procedures which are proposed by different authors or can be found in current design codes such as EN 1994‐1‐1, ANSI/AISC‐360‐05 and JSCE. Comparison of heads stud's and perfobond shear connector's beahviour through experimental results of standard push‐out tests are presented in this paper. Experimentally obtained shear resistance of four headed studs with 16 mm diameter and 100 mm height, positioned in one row into envisaged openings of prefabricated composite decks, with shear resistance of perfobond shear connectors are compared. Main differences in respect of ductility, stiffness and different failure modes which can be noticed for these types of shear connections, obtained from experimental investigation are analyzed in this paper. Comparative analysis includes different shapes, dimensions and specimen's layout of perfobond shear connectors, experimentally investigated through standard push‐out tests which results are available in different literature. Numerical analysis included perfobond shear connectors positioned into envisaged openings of prefabricated composite decks with same dimensions and material properties which are used for numerical analysis of considered headed studs shear connection and which are obtained from experimental investigation. Shear resistance obtained from numerical analysis of perfobond shear connectors are compared with design procedures developed from different authors.
08.56: Horizontal distribution of concentrated loads in ComFlor210 composite slabs
Authors: Abspoel Roland , Stark Jan , Prins Henk 
Published: September 2017

ABSTRACTComposite slabs are built up with a thin‐walled cold‐formed steel deck and interconnected with a concrete topping, see Fig.a).a) Composite slab; b) Cross‐section ComFlor210imageSteel decks can be subdivided into two groups, shallow decks and deep decks, see for an example of a deep deck Fig. b). In EN1994 [1] a subdivision is given based on the spacing of the webs. EN1994 covers only narrow spaced webs which are defined by the ratio, where is the width of the upper flange and is the distance between centres of adjacent ribs. The recommended value for the upper limit of this ratio is br/bs, where br is the width of the upper flange and bs is the distance between centres of adjacent ribs. The recommended value for the upper limit of this ratio is br/bs = 0.6. ComFlor210, a deep steel deck produced by Tata Steel UK, has a ratio br/bs = 425/(546 + 54) = 0.71 > 0.6 and is consequently not covered in EN1994.Composite slabs are designed to transfer loads in one direction i.e. the longitudinal direction of the ribs. However when a concentrated load is acting on a rib, part of the load will be distributed to adjacent ribs. The slab is to be considered as an orthotropic plate.In clause 9.4.3 of EN1994‐1‐1 simplified rules are given for the determination of the effective width. However, as explained above, these rules are only applicable to shallow decks. At Delft University of Technology a research project was carried out to gain better understanding in the horizontal distribution of concentrated loads in deep composite slabs – see reference [2]. In the framework of this project a series of three test specimens was tested in the Stevin II laboratory.
08.57: The friction investigation of CFRP confined CFST specimens with modified concrete
Authors: Evirgen Burak , Tuncan Mustafa , Tuncan Ahmet 
Published: September 2017

ABSTRACTNowadays, concrete filled steel tube (CFST) composite members have in wide range application areas such as transverse beams, piers, slender columns, stub columns, wind turbines etc. around the world. The frictional behavior between concrete and steel tube has a vital role in selection of required size and materials during the laboratory experiments, in‐situ applications and modelling studies. In this study, 16 CFST members were subjected to push out tests within the aim of determination the effect of carbon fibres reinforced polymer (CFRP) confinement and modified concrete at the same time. Modified concrete indicates some mechanical additives are inside the concrete for instance steel fibres, polypropylene fibres and crumb rubber. Furthermore, external CFRP confinement was applied with three different arrangements on the outside circumference of the steel tube. Frictional stress created on the lateral interaction surface ranges between 0.18 MPa and 0.63 MPa due to maximum striping force. Maximum frictional strength was observed on the unconfined reference concrete. Although CFRP application seriously increased the axial strength of composite sections, this process decreases the frictional strength between concrete and steel tube, unexpectedly. Therefore, considering different frictional coefficient emerges as a foregone conclusion during the design procedure of CFRP confined CFST sections.
08.61: A new approach for the serviceability limit state design of composite steel‐concrete slabs
Authors: Ranzi Gianluca 
Published: September 2017

ABSTRACTComposite floors are a well‐established cost‐efficient and effective form of construction. They combine the advantages of two flooring systems that consist of post‐tensioned slabs in concrete structures and of composite slabs in steel structures. These flooring systems include thin‐walled profiled steel sheeting, non‐prestressed reinforcement, concrete and prestressing strands in post‐tensioned slabs. The particularity of composite slabs rely on the ability of the profiled steel sheeting to act as permanent formwork and, once the concrete has hardened, as external reinforcement.This paper provides a brief overview of a new service model for the design of composite and post‐tensioned steel‐concrete floor systems. The serviceability limit state requirements are important for composite floor applications because they usually represent their governing criteria. The proposed approach focuses on the serviceability limit state requirements associated with deflections and places particular attention on the influence of shrinkage on the overall structural response. Recent research has highlighted the occurrence of a non‐uniform shrinkage profile through the composite slab thickness that originates form the inability of the concrete to dry from its underside due to the presence of the profiled steel sheeting. The proposed procedure is validated against selected experimental results available in the literature for composite and post‐tensioned composite slab samples.
09.09: Experimental fatigue analysis of high strength steel structures
Authors: Mecséri Balázs József , Kövesdi Balázs 
Published: September 2017

ABSTRACTThere are contradictional information in the previous studies regarding the relationship between the fatigue strength and the yield strength in case of steel structures. Several previous test result show that the fatigue strength of as‐welded specimens do not depend on the yield strength of the base material. However, several studies show that the fatigue detail class of HSS structure can be higher than for structures made form NSS material for the same structural detail. Collecting the previous fatigue test results of cruciform and flange gusset structural details the effect of the yield strength on the fatigue behaviour is studied. Additional laboratory test program with 32 test specimens is performed to investigate the fatigue behaviour of structural details typically used in bridges produced from HSS and NSS material. For cruciform welded joints the test results show clear correlation between the yield strength and the fatigue life time. For flange gusset joints this relationship cannot be observed. In addition, post weld treatment of the flange gusset plate joint is studied. Using the results of the fatigue tests the fatigue lifetime increase applying the grinding type post‐weld treatment is evaluated.
10.18: Material properties of high strength steel under fire conditions
Authors: Winful Dorothy A. , Cashell Katherine A. , Afshan Sheida , Barnes Adrienne M. , Pargeter Richard J. 
Published: September 2017

ABSTRACTThis paper is concerned with the material characteristics of various commercial high strength structural steels (yield strengths between 460 and 700 N/mm2) under fire conditions. The paper proceeds with a description of the experimental programme which includes two different grades of high strength steel. The aim of this research is to assess (i) the mechanical properties at elevated temperature through tensile testing to support the safe design of fire resistant structures made from high strength steel and (ii) the effect of chemical composition and processing route on the microstructure through a detailed metallurgical investigation. In this paper, a series of isothermal and anisothermal elevated temperature tests are conducted on two commercially‐available steel grades (S690QL and S700MC). Following a detailed description of the tests, the results are analysed to determine strength and stiffness reduction factors at elevated temperatures and these values are compared with literature and EN 1993‐1‐2 (2005). It was found that the results for S700MC, for which there is limited data in the literature, showed better strength retention properties than S690QL at elevated temperatures. The results also showed that under isothermal conditions, the guidance for the elastic moduli of these materials may be unconservative and overly optimistic.
10.20: Numerical simulation of the behaviour of steel members with damaged SFRM fire protection coatings at elevated temperatures
Authors: Zografopoulou Kalliopi , Mistakidis Euripidis 
Published: September 2017

ABSTRACTIn this study an integrated approach to the problem of the fire behaviour of steel members with damaged cementitious SFRM coatings is attempted, by modelling numerically both the mechanical damage of the coating applied on a steel member and the impact that this damage has on the structural behaviour of the steel member under ISO‐834 thermal loading. The numerical study is performed on a steel plate coated with cementitious fire resistive material, and is based on literature results for a test specimen that has been submitted to flexural bending, to study the damage mechanisms of the SFRM coating and the interface bond. Initially, the numerical analysis is performed in normal temperatures to simulate the mechanical damage in the interface and the body of the SFRM coating under flexural load. Then, based on the developed numerical structural model, parametric models of steel plates with SFRM coating that has sustained various degrees of damage are submitted to combined structural and ISO‐834 thermal loading. Coupled thermo‐mechanical analysis is performed to examine the temperature evolution in the steel plate and the evolution of the vertical displacement and the plastic deformations during a 2‐hour thermal exposure.
10.25: Numerical fire tests on the columns of the Cardington steel‐framed building
Authors: Rocha Fabio M. , Albuquerque Gabriela L. , Rodrigues João Paulo C. , Laim Luis 
Published: September 2017

ABSTRACTThe behavior of steel and composite steel and concrete columns with restrained thermal elongation in case of fire has been studied for several years. The influence of the restraining to thermal elongation may, in some cases, have a pernicious effect leading to the sudden collapse of the column but in other cases, for higher values of rotational stiffness, the collapse of the column is slow and gradual.In this paper are presented the results of numerical simulations performed on some of the columns of the BRE's Cardington Steel Framed Building calibrated with results from experimental tests carried out on this building structure by the third author of the paper. They were compared gas and steel temperatures, strains, displacements and rotations of the columns ends.The results of the experimental tests were used to calibrate a numerical model of the entire building structure. In these numerical simulations, performed with the finite element program Abaqus, was considered the fire at different locations in the building. They were calculated strains and displacements at critical points of the structure.This work allowed to study the influence of the thermal restraining on the behavior of the columns when subjected to a localized fire. It could be observed a redistribution of forces along the structure in such a way that the collapse of a column did not affect the stability of the whole building. However the collapse of more than one important column could lead to the collapse of the entire structure.
11.25: Rocking damage‐free steel column base with friction devices: Design procedure and global seismic response of buildings
Authors: Freddi Fabio , Dimopoulos Christoforos A. , Karavasilis Theodore L. 
Published: September 2017

ABSTRACTResilient minimal‐damage steel frames, such as post‐tensioned self‐centering steel frames or steel frames with passive dampers, have been extensively studied but little attention has been paid to their column bases. This paper presents a rocking damage‐free steel column base using post‐tensioned high strength steel bars to control rocking behavior and friction devices that provide stable energy dissipation capacity. Contrary to conventional steel column bases, the monotonic and cyclic hysteretic moment‐rotation behavior of the proposed column base can be easily described using simple analytical equations. The paper describes in detail a step‐by‐step design procedure for the column base that ensures damage‐free behavior and adequate self‐centering and energy dissipation capacity. A finite element model for the column base is developed in OpenSees and used to conduct nonlinear dynamic (seismic) analyses of a building using self‐centering steel moment‐resisting frames. The results of the analyses show that the column base helps the building to avoid damage in the 1st story columns along with eliminating the 1st story residual drifts under both the design and maximum considered earthquake intensities.
11.29: Updates to the ASCE‐41‐13 provisions for the nonlinear modeling of steel wide‐flange columns for performance‐based earthquake engineering
Authors: Hartloper Alexander , Lignos Dimitrios 
Published: September 2017

ABSTRACTPerformance‐based earthquake engineering requires numerical models that are able to reliably predict the expected component behavior of buildings under seismic excitations. The nonlinear modeling guidelines provided in ASCE‐41‐13 have historically been used in this context by practicing engineers. However, for steel wide‐flange columns, the recommendations are primarily based on experimental data that was fairly limited until recently. This paper addresses many of the limitations present in ASCE‐41‐13 for the modeling of steel wide‐flange columns. Recent experimental data from large‐ and full‐scale tests on wide‐flange steel columns, supplemented with detailed finite element studies, has been collected for a wide range of column cross‐sections and applied compressive axial loads. Multiple regression analysis is utilized to develop multivariate predictive equations for the seismic response of steel wide‐flange columns. It is found that the primary contributors that dominate the column response are the local web slenderness, member slenderness and the applied axial load ratio due to gravity loading. Guidelines for developing nonlinear component models for steel columns that can be directly used in both nonlinear static and dynamic analysis procedures are provided. The predicted responses are validated against test data that was not part of the original database. Furthermore, recommendations are proposed for modeling wide‐flange columns subjected to varying axial loads as well as bidirectional loading; and a new limit for force‐controlled elements is proposed for columns under high axial compressive loading and lateral drift demands.
11.40: Cyclic bending of multi‐stiffened plate girders: Numerical model development and analysis
Authors: Dib Abdelkarim , Vigh László Gergely 
Published: September 2017

ABSTRACTDuctile design of steel structures subjected to seismic effects requires creation of dissipative zones. In case of moment resisting frames and eccentrically braced frames, in order to achieve high ductility this requirement often yields to the application of compact sections in the dissipative zone, otherwise premature local plate buckling will govern the design and high ductility cannot be obtained.Buckling resistance of thin web plates of I girder can be significantly increased by application of stiffeners in the web. Vertical stiffeners are often required in seismic links of eccentrically braced frames, but rarely used in moment resisting frames. Application of longitudinal stiffeners is common in bridge structures only. Such stiffeners are typically designed as relatively stiff and strong stiffener, that is characterized by column‐type buckling behaviour, resulting in relatively low ductility.This paper introduces an innovative structural solution: using flexible (i.e. with low rigidity relative to the plate rigidity) multiple longitudinal stiffeners enables plate‐like overall buckling behaviour, which is beneficial with respect to ductility. Although the behaviour of such stiffened plates subjected to monotonic loading is studied in several researches, there is no data available on the cyclic ductility.To study the cyclic behaviour and ductility of such girders, numerical and experimental programme is worked out. This paper primarily focuses on the numerical model development. Shell element numerical model is developed for non‐linear static analysis of the monotonic and cyclic loading. The model is validated by the test results. The developed and verified model is being applied for parametric analysis to study the cyclic performance of various configurations.