Results 21-40 of 106.
Bookmark and Share    
Full Text
Peer Reviewed
See detailNumerical evaluation of the plastic hinges developed in headed stud shear connectors in composite beams with profiled steel sheeting
Vigneri, Valentino UL; Odenbreit, Christoph UL; Braun, Matthias Volker UL

in Structures (2019), 21

For composite beams using novel steel sheeting, the current Eurocode 4 rules sometimes overestimate the load-bearing capacity of headed stud shear connectors. This is due to the larger rib heights and the ... [more ▼]

For composite beams using novel steel sheeting, the current Eurocode 4 rules sometimes overestimate the load-bearing capacity of headed stud shear connectors. This is due to the larger rib heights and the smaller rib widths in comparison with the old studies, which have been carried out to calibrate the current design equations. The RFCS Project “DISCCO” investigated this phenomena and the working group under mandate M515, CEN/TC250/SC4/SC4.T3 is enhancing this equation and working on a proposal to be taken over in the new version of Eurocode 4. The proposed new equation covers the failure behaviour of the shear connection more in detail. The test results show, that the failure consists in a combined concrete cone and stud in bending. Due to the geometry of novel steel sheeting, the load bearing capacity of the headed stud shear connector is no more limited by its shear capacity, but by its bending capacity. A 3D non-linear finite element model is developed and validated through the support of the DISCCO push-out tests. A good agreement between numerical and experimental results in terms of force-slip behaviour is achieved. Special attention of this work lies on the numerical evaluation of the number of plastic hinges n y : a stress-based procedure is presented and the results are compared to the equations presented for new Eurocode 4. The numerical simulations show that the upper plastic hinge moves up as the slip increases due to the progressive crushing of the concrete in the rib. From the parametric study, it turns out that n y is linearly proportional to the embedment depth. Compared to pre-punched hole decking, through-deck welding specimen activates less plastic hinges in the studs because of the higher stiffness provided at the base of the stud. [less ▲]

Detailed reference viewed: 141 (59 UL)
Full Text
Peer Reviewed
See detailDismountable Flooring Systems for Multiple Use
Odenbreit, Christoph UL; Kozma, Andras UL

in IOP Conference Series: Earth and Environmental Science (2019, February), 225

Steel shapes our modern world as an integral part of the global construction economy. In the last decades, the sustainability of steel grew and turned from a linear to a circular business, where the ... [more ▼]

Steel shapes our modern world as an integral part of the global construction economy. In the last decades, the sustainability of steel grew and turned from a linear to a circular business, where the material is fully recovered and recycled after use. The RFCS Research Project “REDUCE” of the European Commission goes one step beyond the mere material recycling and investigates, how the circular economy’s philosophy can be used to reduce the carbon footprint furthermore. On that basis, one target of the research was to develop basic modular and standardised structural load bearing elements which can be adapted in the building or assembled, properly disassembled and partly or entirely be reused again in a subsequent building. This paper presents the respective research results of demountable flooring- and beam systems: 15 large scale push-out tests and two large scale composite beam tests as well as numerous finite element simulations with ABAQUS have been performed at the Laboratory of the ArcelorMittal Chair of Steel and Façade Engineering. The suitability for dis- and re-assembly as well as the strength, stiffness, slip capacity and ductility have been determined. The investigated systems included pre-stressed and epoxy injected systems, as well as solid slabs and composite slabs with profiled decking. The results showed sometimes higher resistances and smaller displacement capacities than conventional systems. The numerical simulation results were presented as well as the results of the laboratory tests. First assessments were given about the respective consequences and about how these consequences could be considered in the layout of future steel composite structures. [less ▲]

Detailed reference viewed: 67 (11 UL)
Full Text
Peer Reviewed
See detailEffective bending stiffness of heavy steel-concrete composite columns with multiple encased steel profiles
Chrzanowski, Maciej UL; Odenbreit, Christoph UL; Degée, Hervé et al

in Proceedings of 9th International Conference on Steel and Aluminium Structures (ICSAS19) (2019)

Detailed reference viewed: 115 (40 UL)
Full Text
See detailStahl und Glas im Bauwesen
Odenbreit, Christoph UL

Scientific Conference (2018, November 21)

Detailed reference viewed: 22 (4 UL)
Full Text
Peer Reviewed
See detailNumerical study on the load bearing capacity of a steel U section beam used as a formwork in constrcution stage
Turetta, Maxime UL; Khelil, Abdelouahab; Odenbreit, Christoph UL et al

Scientific Conference (2018, September 05)

For many categories of buildings, the structural elements must be fire resistant to allow people to evacuate and firefighters to intervene. A new type of steel-concrete composite solution dedicated to ... [more ▼]

For many categories of buildings, the structural elements must be fire resistant to allow people to evacuate and firefighters to intervene. A new type of steel-concrete composite solution dedicated to steel building structures is under development to resist against this fire situation. The solution is composed of a steel U section acting as a formwork for a reinforced concrete part that provides the fire resistance. In order to keep the habits of steel construction, the solution is unpropped in construction stage and the concrete is casted on site. Thus the solution has to resist against three majors situations: the construction stage without propping, the exploitation stage and the fire situation. The steel part of the composite beam is then designed to face the construction stage without propping. The present paper describes the numerical investigations carried out on the load bearing capacity of this steel section in construction stage. The objective of these investigations is to finally propose a steel solution stable and resistant for its use during construction stage. The numerical model of the steel section and its boundary conditions are presented. A first elastic calculation is used to determine the Eigen modes of the beam that give the shape of initials imperfections. Then analysis considering materials non-linearity and geometrical imperfections (GMNIA calculation) are carried out. A sensitivity study on the influence of the geometrical imperfections on the load bearing capacity of the beam is performed. Then, with the more conservative initial imperfection, a study on the global stability of the beam without any intermediate restraint is carried out. Finally, to overcome the problem of instability in construction stage, the restraint induced by the perpendicular steel decks is investigated. [less ▲]

Detailed reference viewed: 156 (18 UL)
Full Text
See detailNeues Bemessungsmodell für Kopfbolzendübel in Kombination mit hohen Trapezblechprofilen
Odenbreit, Christoph UL; Lam, Dennis; Hicks, Stephan et al

Scientific Conference (2018, August 31)

Detailed reference viewed: 27 (4 UL)
Full Text
Peer Reviewed
See detailPush-out tests on demountable shear connectors of steel-concrete composite structures
Kozma, Andras UL; Odenbreit, Christoph UL; Braun, Matthias Volker UL et al

in Proceedings of the 12th International Conference on Advances in Steel-Concrete Composite Structures (2018, June 27)

The deconstruction of steel-concrete composite structures in buildings and the later separation of the materials is a labour- and cost intensive work. The shear studs are welded on the steel beam and ... [more ▼]

The deconstruction of steel-concrete composite structures in buildings and the later separation of the materials is a labour- and cost intensive work. The shear studs are welded on the steel beam and imbedded in the concrete deck and a large amount of cutting work becomes necessary. As a result, recycling is difficult and the potential for reusing entire elements is lost. The carbon footprint of composite structures could be decreased by application of the principles of “design for deconstruction and reuse”. This paper presents a desk top study and corresponding laboratory experiments on demountable shear connectors that facilitate recyclability and even provide the potential for reusing complete structural elements. In the Laboratory of Steel and Composite Structures of the University of Luxembourg 15 push-out tests have been carried out using different bolted connection systems suitable for multiple uses in order to verify their performance focusing on shear strength, stiffness, slip capacity, ductility and ability of demounting. The investigated systems included pre-stressed and epoxy resin injection bolts, solid slabs and composite slabs with profiled decking. The results showed that the tested demountable shear connections could provide higher shear resistance than conventional shear connections. The critical failure mode is shear failure of the bolts, while there was no visible damage observed on the connected members. Most of the tested connections could fulfil the ductility requirement according to by Eurocode 4. The application of epoxy resin in the hole clearance resulted in lower slip capacity. The outcome provides an important basis for the justification of the forthcoming enhancement and validation of numerical models of the demountable shear connections. The failure behaviour, the observed damages and the resulting ability of the elements for re-use are discussed in detail. [less ▲]

Detailed reference viewed: 235 (15 UL)
Full Text
Peer Reviewed
See detailDevelopment of an innovative type of shear connector dedicated to fully embedded steel-concrete composite columns - experimental and numerical investigations
Chrzanowski, Maciej UL; Odenbreit, Christoph UL; Obiala, Renata et al

in Proceedings of the ASCCS 2018 Conference, Valencia, Spain, June 27-29, 2018 (2018, June)

Detailed reference viewed: 118 (11 UL)
Full Text
See detailReuse and Demountability Using Steel Structures and the Circular Economy
Odenbreit, Christoph UL; Kozma, Andras

Scientific Conference (2018, February 26)

Detailed reference viewed: 34 (6 UL)
Full Text
Peer Reviewed
See detailFailure behaviour of silicone adhesive in bonded connections with simple geometry
Staudt, Yves UL; Odenbreit, Christoph UL; Schneider, Jens

in International Journal of Adhesion and Adhesives (2018), 82

In façade structures, adhesively bonded connections between glass panels and metallic substructures represent an attractive alternative to mechanical fixation devices. Apart from positive aspects ... [more ▼]

In façade structures, adhesively bonded connections between glass panels and metallic substructures represent an attractive alternative to mechanical fixation devices. Apart from positive aspects regarding the construction's energy efficiency and aesthetics, the uniform load transfer reduces stress concentrations in the adherends, which is beneficial especially regarding brittle materials like glass. Structural silicone sealants are generally used for these kind of applications due to their excellent adhesion on glass and their exceptional resistance against environmental influences and ageing. For the verification of the bonded connection, non-linear numerical simulations, such as the Finite Element Method, are increasingly used. The resulting three-dimensional stress states need to be assessed with the help of an appropriate failure criterion. In this paper, an overview is given on available failure criteria for rubber-like materials. The applicability of these criteria on the silicone sealant is verified regarding three characteristic stress states: uniaxial tension, shear and compression. The proposed engineering failure criterion is the true strain magnitude, which is valid for bonded connections in form of linear beads for cohesive failure of the adhesive. For Dow Corning® 993 structural silicone sealant, the strain magnitude, evaluated using true strains, at failure could be determined as 1.6. [less ▲]

Detailed reference viewed: 156 (14 UL)
Full Text
Peer Reviewed
See detailNumerical evaluation of the plastic hinges developed in headed stud shear connectors in composite beams with profiled steel sheeting
Vigneri, Valentino UL; Odenbreit, Christoph UL; Braun, Matthias Volker UL

in Proceedings of the 12th International Conference on Advances in Steel-Concrete Composite Structures (2018)

For composite beams using novel steel sheeting, the current Eurocode 4 rules sometimes overestimate the load bearing capacity of the shear connector. This is due to the larger rib heights and the smaller ... [more ▼]

For composite beams using novel steel sheeting, the current Eurocode 4 rules sometimes overestimate the load bearing capacity of the shear connector. This is due to the larger rib heights and the smaller rib widths in comparison with the old studies, which have been carried out to calibrate the current design equations. The RFCS Project “DISCCO” investigated this phenomena and the working group under mandate M515, CEN/TC250/SC4/SC4.T3 is enhancing this equation and working on a proposal to be taken over in the new version of Eurocode 4. The proposed new equation covers the failure behaviour of the shear connection more in detail. The test results show, that the failure consists in a combined concrete cone and stud in bending. Due to the geometry of novel steel sheeting, the load bearing capacity of the headed stud shear connector is no more limited by its shear capacity, but by its bending capacity. A 3D non-linear finite element model is developed and validated through the support of the DISCCO push-out tests. A good agreement between numerical and experimental results in terms of force-slip behaviour is achieved. Special attention of this work lies on the numerical evaluation of the number of plastic hinges ny: a stress-based procedure is presented and the results are compared to the equations presented for new Eurocode 4. The numerical simulations show that the upper plastic hinge moves up as the slip increases due to the progressive crushing of the concrete in the rib. From the parametric study, it turns out that ny is linearly proportional to the embedment depth. Compared to pre-punched hole decking, through-deck welding specimen activates less plastic hinges in the studs because of the higher stiffness provided at the base of the stud. [less ▲]

Detailed reference viewed: 147 (17 UL)
Full Text
Peer Reviewed
See detailNew mechanical model to predict the load bearing resistance of shear connectors with modern forms of profiled sheeting
Odenbreit, Christoph UL; Vigneri, Valentino UL; Amadio, Claudio et al

Scientific Conference (2018)

The rules in EN1994-1-1 concerning the resistance of shear connections in composite beams with headed shear studs and steel sheeting relies on push-out tests, which have been performed between the late ... [more ▼]

The rules in EN1994-1-1 concerning the resistance of shear connections in composite beams with headed shear studs and steel sheeting relies on push-out tests, which have been performed between the late seventies and the early nineties of the last century. In the recent years, new geometries of metal decking have appeared on the market with the target to reduce the volume and weight of the concrete slab and to maximise the slab efficiency. The influence of these new geometries on the load bearing behaviour of shear connections has to be verified. Amongst others, the RFCS research project DISCCO investigated the shear stud resistance in combination with such novel steel decking. It turned out that, the current EN 1994-1-1 rules need to be modified especially for metal decking with narrow and deep deck ribs. Alternative analytical equations for the estimation of the shear resistance have been derived and statistically evaluated according to EN 1990. Details are presented in this contribution. [less ▲]

Detailed reference viewed: 147 (37 UL)
Full Text
Peer Reviewed
See detailA new method to assess the stiffness and rotation capacity of composite joints
Duarte da Costa, Job; Obiala, Renata; Odenbreit, Christoph UL

in Proceedings of the 12th International Conference on Advances in Steel-Concrete Composite Structures. ASCCS 2018 (2018)

Composite beam-to-column joints in buildings are mostly modelled as pinned joints in order to facilitate the design of the structure. In reality, due to the required reinforcement in the concrete slab, a ... [more ▼]

Composite beam-to-column joints in buildings are mostly modelled as pinned joints in order to facilitate the design of the structure. In reality, due to the required reinforcement in the concrete slab, a certain joint rigidity and bending resistance is always available. The real joint behaviour corresponds therefore more to that of a semi-continuous joint. This is not only beneficial for the serviceability limit state but can also be advantageous at ultimate limit state. However, due to the lack of analytical design rules in EN 1994 to verify the rotation capacity of semi-continuous joints, these are commonly modelled as pinned joints, which impedes an efficient design of composite structures. In this context, a research program on the behaviour of composite joints, focusing on the ultimate rotation capacity, was initiated at the University of Luxembourg [1]. The aim was to identify the influence of two major joint components – the reinforced concrete slab and the steelwork connection – on the moment-rotation curves of composite joints under hogging bending moment. An experimental campaign comprising 8 tests on beam-tocolumn joints was conducted to determine the response of composite joints with variable reinforcement ratio and diameter of reinforcing bars. In addition to the experimental part, an FE model was developed with the software ABAQUS aiming to simulate the behaviour of internal beam-to-column composite joints. In this paper, the 3D finite element model and results of analyses are presented. The FE model has been defined by 3D solid elements with realistic contact definitions and nonlinear material laws. The results of the numerical simulations presented a good agreement with the experimental data. Based on the experimental and numerical investigations, the influence of reinforcement and steelwork connection on the structural properties of composite joints is derived. A new analytical method to determine the stiffness and rotation capacity of composite joints is proposed. The accuracy of this new method is confirmed by existing experimental and numerical results. [less ▲]

Detailed reference viewed: 33 (6 UL)
Full Text
See detailSteel and Composite Structural Building Elements for a Circular Economy
Odenbreit, Christoph UL

in Steel and Composite Structural Building Elements for a Circular Economy (2017, November 07)

Detailed reference viewed: 22 (3 UL)
Full Text
Peer Reviewed
See detailShear Stresses Analysis at the Steel-Concrete Interface with the Usage of Bond Eliminating Products
Chrzanowski, Maciej UL; Odenbreit, Christoph UL; Obiala, Renata et al

in Proceedings of the XI CMM 2017 Conference, Coimbra 23-24 November 2017 (2017, November)

Detailed reference viewed: 63 (12 UL)
Full Text
Peer Reviewed
See detailMechanical Model to Predict the Resistance of the Shear Connection in Composite Beams with Deep Steel Decking
Odenbreit, Christoph UL; Nellinger, Sebastian UL

in Eurosteel 2017 (2017, September 13)

The resistance of a typical shear connection with headed shear studs in a composite beam is analysed in the normal case in accordance with EN 1994-1-1. The reducing effect of a trapezoidal metal decking ... [more ▼]

The resistance of a typical shear connection with headed shear studs in a composite beam is analysed in the normal case in accordance with EN 1994-1-1. The reducing effect of a trapezoidal metal decking onto the ultimate load bearing capacity is considered with empirically derived reduction factors and equations, which have been developed in the last century between the late 70th and the early 80th. The RFCS research project “DISCCO” investigated the shear stud resistance with novel types of steel decking. In many cases, the shear resistance, which was predicted by EN 1994-1-1 was not reached in tests. In the respective experiments with composite beams and deep decking, a concrete cone failure mode was identified and not a pure shear failure of the stud. This failure mode acted in combination with the load bearing capacity of the shear stud, which formed one or two plastic hinges in the shaft - depending on the available geometry. Based on these observations, new equations have been developed to predict the shear connection’s resistance with more accurcy. The yield hinge mechanism of the shear stud, which was developed by Lungershausen, was extended by the above mentioned load bearing component ‘concrete cone’. The formulae consider the geometry of the stud and the steel decking, the material strength of the stud and of the concrete material. The statistical evaluation of the developed equations shows a good accordance with test results. [less ▲]

Detailed reference viewed: 134 (11 UL)
Full Text
Peer Reviewed
See detailExperimental investigations on semi-continuous encased composite joints
Duarte Da Costa, Job UL; Obiala, Renata UL; Odenbreit, Christoph UL

in Eurosteel 2017 (2017, September 13)

The benefits brought to composite construction by the use of semi-continuous joints are well recognised and confirmed by the significant amount of research which has been performed in this area. It has ... [more ▼]

The benefits brought to composite construction by the use of semi-continuous joints are well recognised and confirmed by the significant amount of research which has been performed in this area. It has been analytically proven that at serviceability limit state (SLS) the performance of composite beams benefits from the use of semi-continuous composite joints [1]. At ultimate limit state (ULS) it is of common knowledge that the use of semi-continuous composite joints is only judicious in combination with the plastic hinge theory, which requires the verification of the rotation capacity of the joint. Despite all the effort done in this area, a concise and well-defined method to determine the rotation capacity of composite joints is lacking. Hence, a research programme with a large experimental part has been designed to investigate the behaviour of the connection between a column and a composite slim-floor beam subjected to a negative bending moment. It is the first time that the rotation capacity of an encased composite joint is analysed. The experimental campaign, presented in here, aims at determining the influence of each joint component on the rotation capacity of composite joints. Three test series have been performed; on boltless beam-to-column connections using variable longitudinal reinforcement ratio and bar diameter of the slab, on a bare bolted end-plate steel connection without reinforced concrete slab and finally on the encased composite joint with the complete bolted end-plate connection. This paper presents a detailed description of the tested specimen, shows the main results of the experimental investigations and gives an outlook on future work regarding this research project. The final goal of the research project is to develop a comprehensive methodology to predict the rotation capacity for traditional and slim-floor type of composite beams. [less ▲]

Detailed reference viewed: 161 (16 UL)