References of "Odenbreit, Christoph 50002778"
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See detailDifferent load‐bearing mechanisms in headed stud shear connections in composite beams with profiled steel sheeting
Vigneri, Valentino UL; Odenbreit, Christoph UL; Lam, Dennis

in ce/papers (2019, September), 3(3-4), 231-236

The current regulations of EN1994-1-1 for headed stud shear connections in composite beams with profiled sheeting lead, for some configurations, to an over-estimation of the load-bearing capacity. Since ... [more ▼]

The current regulations of EN1994-1-1 for headed stud shear connections in composite beams with profiled sheeting lead, for some configurations, to an over-estimation of the load-bearing capacity. Since these design equations are based on empirical considerations, they are not able to capture the real mechanical behaviour of the connector and they do not consider appropriately the influence of the geometry of sheeting on the shear capacity. For this reason, the load-bearing mechanisms of the shear connection are identified in this work with the support of experimental and numerical results. According to the static system presented, the concrete rib is modelled as a system of diagonal struts acting simultaneously in combination with the stud in bending. It is observed that at 2÷4 mm slip, a ?Strut and beam? mechanism prevails where the resistance of the connector depends mostly on the plastic hinges activated in the stud and on the capacity of the diagonal strut in front of it. By increasing the slip (ca. 4÷10 mm), the surrounding concrete progressively crushes while the tensile stresses at the edge of the rib reach the tensile strength of the material. As a consequence of this loss of rotational stiffness, the bending capacity developed in the stud reduces and the upper hinges gradually moves towards the slab. At higher displacements (ca. 20÷40 mm), due to nonlinear geometric effects, high tensile forces develop in the stud and the load is carried through a ?Strut and Tie? resistance mechanism, if the embedment of the stud is sufficient. By further increasing the slip, the whole rib rotates or the failure occurs either for concrete pull-out or stud rupture. This contribution describes the sequence of the activated load-bearing mechanisms in headed stud shear connections with profiled steel sheeting at different displacements. [less ▲]

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See detailDifferent load bearing mechanisms in headed stud shear connectors for composite beams with profiled steel sheeting
Vigneri, Valentino UL; Odenbreit, Christoph UL; Lam, Dennis

in Steel Construction (2019), 12(3), 184-190

The current design rules of EN 1994-1-1 covering headed stud shear connectors for composite beams with profiled sheeting lead, in some cases, to an overestimation of the load bearing capacity. Owing to ... [more ▼]

The current design rules of EN 1994-1-1 covering headed stud shear connectors for composite beams with profiled sheeting lead, in some cases, to an overestimation of the load bearing capacity. Owing to their empirical nature, these equations are not able to capture the real behaviour of the connector. Therefore, the load bearing mechanisms of the shear connection are identified in this work with the support of experimental and numerical results. According to the static system proposed, the concrete rib is modelled as a system of diagonal struts in combination with the stud in bending. It was observed that at 1-4 mm slip, a 'strut and beam' mechanism prevails, where the resistance of the connector depends on the activation of the plastic hinges in the stud and on the capacity of the diagonal strut in front of it. By increasing the slip (approx. 4-10 mm), the surrounding concrete gradually crushes, while the tensile stresses at the edge of the rib reach the tensile strength of the material. Because of this loss of rotational stiffness, the bending moment in the stud decreases and the upper plastic hinge gradually moves towards the slab. At higher displacements (approx. 20-40 mm), high tensile forces develop in the stud due to non-linear geometric effects and the load is carried through a 'strut and tie' resistance mechanism, provided that the embedment of the stud is sufficient to prevent the rotation of the rib. As the slip increases further, failure occurs either in the form of concrete pull-out or stud rupture. [less ▲]

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See detailTragverhalten von CoSFB-Dübeln
Braun, Matthias; Obiala, Renata; Schäfer, Markus UL et al

in Stahlbau (2019), 88(2019)(Heft 7),

Slim-floor or shallow floor construction is characterized by the integration of a steel beam into a slab. The activation of a composite action between the steel section and the concrete slab leads to a ... [more ▼]

Slim-floor or shallow floor construction is characterized by the integration of a steel beam into a slab. The activation of a composite action between the steel section and the concrete slab leads to a significant increase of the bending capacity and the stiffness of the beam, allowing for larger beam spans. This paper presents a fundamentally new method for assessing the load-bearing capacity of CoSFB-Dowels, which ensures a composite action of a composite slim-floor beam (CoSFB). Based on detailed analysis of push-out tests, extensive numerical simulations were performed in order to identify the contribution of various parameters on the load-bearing capacity. Finally, an analytical formulation of the load-bearing capacity is presented, which has been derived by applying a simple second order plasticity approach. [less ▲]

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See detailEquations to predict the shear connection capacity of composite beams with slender profiled steel sheeting
Odenbreit, Christoph UL; Vigneri, Valentino UL; Lam, Dennis

Scientific Conference (2019, July)

The rules of EN1994-1-1 for shear connections in composite beams with deep profiled sheeting sometimes lead to an overestimation of the load bearing capacity of the respective shear connection. The ... [more ▼]

The rules of EN1994-1-1 for shear connections in composite beams with deep profiled sheeting sometimes lead to an overestimation of the load bearing capacity of the respective shear connection. The estimation of the impact of the sheeting shape on the calculated connection resistance is based on test results from the late seventies until the early nineties. Meanwhile, new products have appeared on the market with the target to reduce the volume and weight of the concrete in order to maximize the slab efficiency. However, the corresponding effects onto the shear connection have been underestimated because the use of deeper and more narrow deck rib lead to a more slender profile with a changed failure behaviour. Instead of the shearing-off failure of the stud, a combination of concrete cone failure and plastic bending of the stud – with one or two plastic hinges - was identified in laboratory tests. Based on the observed failure mechanisms, a new mechanical model with respective analytical equations for the shear resistance of headed studs in profiled steel sheeting was proposed. The new model extends the yield hinge mechanism, which was developed by Lungershausen [1], to more precisely predict the formation of the number of yield hinges depending on the mechanical and geometrical properties with the support of a finite element model. The complete equations consider the geometry of the stud and the steel decking as well as the material strengths of the stud and concrete. The statistical evaluation shows a good accordance with the developed model and analytical design equations. This contribution presents the new design equations and their background describing the mechanical model, the numerical study and statistical evaluation of push-out test results. [less ▲]

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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

in Structures (2019)

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 ▲]

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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)

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 ▲]

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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)

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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 ▲]

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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 ▲]

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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)

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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 ▲]

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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 & 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 ▲]

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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 ▲]

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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)

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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 ▲]

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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 ▲]

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