References of "Hanus, François"
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See detailAnalysis of simple connections in steel structures subjected to natural fires
Hanus, François ULg

Doctoral thesis (2010)

Until recently, investigations on the fire resistance of steel joints have been neglected by structural engineers under the arguments that the design resistance of connections at room temperature is ... [more ▼]

Until recently, investigations on the fire resistance of steel joints have been neglected by structural engineers under the arguments that the design resistance of connections at room temperature is usually higher than the resistance of the connected members and that the temperature increases more slowly in the joint zone (high concentration of mass, low exposure to radiative fluxes) than in the adjacent beams and columns. However, brittle failures of connection components have been observed especially during the cooling phase of real fires for two main reasons: the high sensitive and non-reversible character of the resistance of bolts and welds at elevated temperatures and the development of high tensile thrusts. The present thesis is a contribution to the understanding of the thermo-mechanical behaviour of simple connections in steel beam-to-column joints subjected to natural fire conditions, with a special attention to the behaviour of these connections during the cooling phase. The distribution of temperature in joints has been analysed by use of numerical models built in SAFIR software. The simplified methods presently mentioned in the Eurocodes are discussed and new methods, calibrated on the results of numerical simulations, are proposed in the present work to predict the temperature profile in steel beams and joints covered by a flat concrete slab under fire. An existing method aimed at evaluating the distribution of internal forces in restrained steel beams (and by extension, in joints) under natural fire has been analysed in detail. Several modifications have been added in order to improve this method and to extend its field of application. The final version of this analytical method has been implemented and validated against numerical results. An experimental programme aimed at characterising the mechanical behaviour of bolts and welds under heating and subsequent cooling is described in the present thesis. The properties of the tested specimens, the thermal loading applied to these specimens, the test set-ups and the results of the tests are reported in detail. Mechanical models for bolts loaded in tension or in shear have been calibrated on the experimental results. The loss of resistance of bolts and welds due to their non-reversible behaviour under heating and subsequent cooling has been quantified. Finally, a large part of the thesis is dedicated to the development of component-based models representing the action of common simple connections under natural fire conditions and to the analysis of the behaviour of these connections as a part of a sub-structure or large-scale structure. These simple models can be used for parametric analyses because it conciliate a reasonable time of definition of the data, an acceptable time of simulation and a good degree of accuracy of the results. Recommendations for the design of connections have been defined. The ductility of connections has a major influence on the occurrence of connection failures and classes of ductility for connections, dependant of the fire loading, have been defined in this work. [less ▲]

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See detailExperimental investigations and analytical models for behavior of Grade 8.8 bolts and butt welds under heating and subsequent cooling
Hanus, François ULg; Zilli, Giuliana; Franssen, Jean-Marc ULg

in kodur, venkatesh; Franssen, Jean-Marc (Eds.) Structures in Fire - Proceedings of the Sixth International Conference (2010, June 03)

The present article describes the experimental tests undertaken on Grade 8.8 tests and butt welds at the Centro Sviluppo Materiali during heating or subsequent cooling, presents a model for the force ... [more ▼]

The present article describes the experimental tests undertaken on Grade 8.8 tests and butt welds at the Centro Sviluppo Materiali during heating or subsequent cooling, presents a model for the force-displacement diagram of bolts during a natural fire that integrates the influence of the temperature history, and gives values of strength reduction factors for the cooling phase [less ▲]

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See detailEvaluation of Structural Fire Performance. Today and Tomorrow
Franssen, Jean-Marc ULg; Gernay, Thomas ULg; Hanus, François ULg et al

Conference given outside the academic context (2010)

The most recent applications in evaluation of structural fire performance performed at the University of Liege are described. Five topics are discussed: analysis of 3D structures, joints in steel ... [more ▼]

The most recent applications in evaluation of structural fire performance performed at the University of Liege are described. Five topics are discussed: analysis of 3D structures, joints in steel structures, spalling in concrete structures, cellular beams and tensile membrane action. [less ▲]

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See detailTechnisch rapport TR3 MP0.4 - Case study industriegebouw
Pyl, Lincy; Lansival, Jean-Baptiste; Hanus, François ULg

Report (2010)

Ce rapport décrit le calcul de la résistance au feu d'un hall industriel sous feu naturel et contient trois parties : l'évaluation de la distribution de température dans le compartiment, l'échauffement de ... [more ▼]

Ce rapport décrit le calcul de la résistance au feu d'un hall industriel sous feu naturel et contient trois parties : l'évaluation de la distribution de température dans le compartiment, l'échauffement de la structure et sa stabilité. [less ▲]

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See detailBehaviour of single sided composite joints at room temperature and in case of fire after an earthquake
Demonceau, Jean-François ULg; Hanus, François ULg; Jaspart, Jean-Pierre ULg et al

in International Journal of Steel Structures (2009), 9(4), 329-342

In 2003, a European research program entitled “PRECIOUS - Prefabricated composite beam-to-concrete filled tube or partially reinforced-concrete-encased column connections for severe seismic and fire ... [more ▼]

In 2003, a European research program entitled “PRECIOUS - Prefabricated composite beam-to-concrete filled tube or partially reinforced-concrete-encased column connections for severe seismic and fire loadings” and funded by the Research Fund for Coal and Steel (RFCS) was initiated for three years (Bursi et al, 2008). The objective of this project was to develop fundamental data, design guidelines and prequalification tools for two types of composite beam-to-column joints able to ensure a suitable behaviour during an earthquake and its eventual subsequent fire. At the University of Liege, as part of this project, analytical and numerical investigations were conducted mainly on single-sided beam-to-column composite joints at room and at elevated temperatures. The present paper summarizes the activities developed within this project and presents the main achievements. [less ▲]

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See detailCalculation of internal forces in axially and rotationally restrained beams under natural fire
Hanus, François ULg

Master of advanced studies dissertation (2008)

When a constituent of a frame is subjected to fire, the thermal dilatation and bowing of this element is limited by the action of the surrounding frame. The reduction of steel mechanical properties and ... [more ▼]

When a constituent of a frame is subjected to fire, the thermal dilatation and bowing of this element is limited by the action of the surrounding frame. The reduction of steel mechanical properties and restrained thermal deformations induce a new distribution of internal forces in the frame. Generally, the stability of structures is calculated by the use of recommended temperature-time curves that do not considered the cooling phase of the fire. After being submitted to high compressive forces and experiencing significant plastic deformations, heated elements become in tension. As it was observed experimentally, the failure of bolts due to an excess of tensile forces may occur during the cooling phase of the fire. That is the reason why a research project on the design of connections subjected to natural fire (COSSFIRE) has been funded by the Research Fund for Coal and Steel (RFCS). The objective of this project is to provide experimental data and to propose guidelines for designing the joints including both the heating and cooling phases. This work describes a part of the contribution of the University of Liège in the project COSSFIRE. It is focused on the determination of the internal forces experienced by axially and rotationally restrained beams submitted to a natural fire. This preliminary step is essential for an optimised design of connections in similar conditions. This work is subdivided three parts. Firstly, some experimental tests have been modelled numerically with the homemade finite element software SAFIR in order to validate it and the models used to analyse this type of problem. Secondly, a set of parametrical analyses have been performed in order to better understand the influence of several factors on the induced internal forces and provide some reference results for the last part of the work. Finally, some simplified methods, based on Wang’s method, have been defined to allow determining the internal forces in a given case without requiring any numerical simulation in finite element packages. [less ▲]

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See detailPrefabricated composite beam-to-concrete filled tube or partially reinforced-concrete-encased column connections for severe seismic and fire loadings
Bursi, Oreste; Ferrario, Fabio; Haller, Mike et al

Report (2008)

Detailed reference viewed: 98 (12 ULg)
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See detailCalcul de la résistance au feu d'ouvrages d'art en intégrant l'éclatement du béton
Franssen, Jean-Marc ULg; Hanus, François ULg; Dotreppe, Jean-Claude ULg

Scientific conference (2007, July 06)

Les ouvrages en béton présentent en général une bonne résistance au feu. Toutefois, dans certaines situations, l'apparition de phénomènes d'éclatement peut mener à une réduction rapide et marquée de la ... [more ▼]

Les ouvrages en béton présentent en général une bonne résistance au feu. Toutefois, dans certaines situations, l'apparition de phénomènes d'éclatement peut mener à une réduction rapide et marquée de la résistance des éléments concernés. Les tunnels, qui sont souvent soumis à des incendies de très forte intensité, subissent très souvent la perte de leurs premières couches intérieures pouvant conduire à la mise à nu des armatures. dans cet article, on montre comment le logiciel SAFIR peut être utilisé pour effectuer une analyse de risque en intégrant des valeurs plausibles de l'éclatement. ce concept sera illustré par l'examen d'une structure particulière. [less ▲]

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See detailEtude de la résistance au feu de deux ponts-cadres sur le Canal du Centre
Hanus, François ULg; janssen, David; Franssen, Jean-Marc ULg

Report (2007)

The fire resistance of two short concrete tunnel is evaluated in the scenario of a trafic accident. Theses two tunnels are under a canal in Belgium.

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See detailNumerical evaluation of the fire behaviour of a concrete tunnel integrating the effects of spalling
Franssen, Jean-Marc ULg; Hanus, François ULg; Dotreppe, Jean-Claude ULg

in Proceedings of the Fire Design of Concrete Structures from Materials Modelling to Structural Performance Workshop (2007)

Detailed reference viewed: 67 (5 ULg)