References of "Franssen, Jean-Marc"
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See detailAxially Loaded Stainless Steel Columns in Case of Fire
Lopes, Nuno; Vila Real, Paulo; Simões da Silva, Luís et al

in Journal of Structural Fire Engineering (2010), 1(1), 43-59

The simple model of Eurocode 3, for the fire resistance evaluation of stainless steel members, are based on the procedures used for carbon steel structural elements. However, due to the existing ... [more ▼]

The simple model of Eurocode 3, for the fire resistance evaluation of stainless steel members, are based on the procedures used for carbon steel structural elements. However, due to the existing differences in the constitutive laws of these two materials, it is expected that it would not be possible to use, in both materials, the same formulae for the member stability calculation, as proposed in Eurocode 3. This paper aims at increasing the knowledge on the behaviour of stainless steel axially loaded columns at elevated temperatures. For this purpose, a geometrical and material non linear computer code has been used to determine the buckling load of these elements. The Eurocode formulae are evaluated and a new proposal, that ensures accurate and conservative results when compared with the numerical simulations, is presented. [less ▲]

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See detailEvaluation de la capacité portante d'une structure en béton ayant subi un incendie
Franssen, Jean-Marc ULg

Learning material (2010)

What are the different missions that can be given to an expert about the assessment of the load bearing capacity of a concrete structure that has been subjected to a fire? How can he accomplish these ... [more ▼]

What are the different missions that can be given to an expert about the assessment of the load bearing capacity of a concrete structure that has been subjected to a fire? How can he accomplish these missions. [less ▲]

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See detailExpertise maison de Groote
Franssen, Jean-Marc ULg

Report (2010)

Estimation des effets d'un incendie sur la capacité portante de la structure en béton

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See detailNumerical Modelling of Thin-Walled Stainless Steel Structural Elements in Case of Fire
Lopes, Nuno; Vila Real, Paulo; Simoes da Silva, Luís et al

in Fire Technology (2010), 46(1), 91-108

In this paper, the structural response of stainless steel thin-walled elements submitted to fire is analysed numerically by means of the geometrically and materially non-linear Finite Element program ... [more ▼]

In this paper, the structural response of stainless steel thin-walled elements submitted to fire is analysed numerically by means of the geometrically and materially non-linear Finite Element program SAFIR, including imperfections. In order to make these simulations, two main changes in the program were made: (i) the code was changed in order to deal with the stainless steel 2D material constitutive law to be used with shell elements and (ii) the possibility of the program to take into account residual stresses with shell finite elements was introduced. The stainless steel stress–strain relationship at high temperatures was based on the one presented in part 1.2 of Eurocode 3. To model the strain hardening exhibited by the stainless steels, using the shell element formulation, an approximation to the Eurocode 3 constitutive law was needed. Local and global geometrical imperfections were considered in the simulations. The paper shows the influence of the residual stresses on the ultimate load-carrying capacity of thin-walled stainless steel structural elements in case of fire. [less ▲]

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See detailDistribution of temperature in steel and composite beams and joints under natural fire
Hanus, François; Franssen, Jean-Marc ULg

in Cahier Scientifique - Revue Technique Luxembourgeoise (2010), 2

The present article describes the existing methods and recommendations for the evaluation of temperature profiles in steel beams and joints covered by a concrete slab. Then, modifications and improvements ... [more ▼]

The present article describes the existing methods and recommendations for the evaluation of temperature profiles in steel beams and joints covered by a concrete slab. Then, modifications and improvements to the existing methods are proposed in order to predict more accurately temperatures at the level of the top flange of the beam by accounting for heat fluxes between the steel elements and the concrete slab. The two methods presented in this article differ by the degree of simplicity, the field of applicability and the accuracy of the predicted results. Comparisons with numerical simulations performed in the finite element program SAFIR have been described for the validation of these new methods. It is assumed in these numerical models that the contact between the steel profile and the concrete slab is perfect. The “original” Lumped Capacity Method gives globally good predictions of temperature in steel and composite beams and joints but does not integrate heat fl uxes between the steel elements and the concrete slab. This leads to an over-estimation of temperature in the steel elements during the heating phase and to an under-estimation of temperature during the cooling phase. In order to take these fluxes into consideration in the evaluation of the top flange temperature, it is suggested in the first proposed method to integrate a part of the concrete slab into the heated surface or volume considered in the Lumped Capacitance Method. The Composite Section Method correctly predicts temperature at the level of the top flange under ISO fire or during the heating phase of parametrical fire curves but a delay is observed between these analytical results and those obtained from numerical simulations performed in SAFIR software. In a second method, called Heat Exchange Method, it is proposed to calculate separately the heat fluxes between, on one side, the top flange and, on the other side, the gases of the compartment, the rest of the steel section and the concrete slab. The temperatures given by this latter method are in very good agreement with those obtained from FE models. The use of this method is really less fastidious than the use of FE models, especially for joints, but is limited to a certain type of fire curves (parametrical fire curves defined in the Annex A of the EN 1991-1-2). Finally, a bilinear temperature profi le has been proposed to interpolate the analytically-calculated temperatures at the level of the top and bottom flanges on the total height. This procedure is simple and shows a good agreement with the numerical results in 2-D beam sections and 3-D joint zones during the heating and cooling phases of parametric fire curves. [less ▲]

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See detailSteel Hollow Columns filled with self compacting Concrete under Fire Conditions
Dotreppe, Jean-Claude ULg; Chu, Thi Binh; Franssen, Jean-Marc ULg

in The third International Congress and Exhibition - Proceedings Disc (2010)

Concrete filled steel hollow section (CFSHS) columns can carry important loads and therefore are used extensively in the construction of high-rise buildings. Steel hollow sections are filled usually with ... [more ▼]

Concrete filled steel hollow section (CFSHS) columns can carry important loads and therefore are used extensively in the construction of high-rise buildings. Steel hollow sections are filled usually with ordinary concrete, but filling problems may arise with small cross sections and dense reinforcement or hollow sections (tubes) surrounding another profile (tube or H section) when the distance between the two profiles is small. For such a configuration, self-compacting concrete can be recommended. Ten columns filled with self-compacting concrete embedding another steel profile have been tested in the Fire Engineering Laboratory of the University of Liege - Belgium. The non linear finite element software SAFIR developed at the University of Liege has been used to simulate the thermal and structural behavior under fire conditions. A good agreement between numerical and experimental results has been obtained. This shows that SAFIR code can predict well the behavior of CFSHS columns and that the properties of self-compacting concrete at high temperatures can be considered to be the same as those of ordinary concrete. Another purpose of this study was to give practical tools to consulting engineers. [less ▲]

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See detailStructures in Fire. Proceedings of the Sixth International Conference
Kodur, Venkatesh; Franssen, Jean-Marc ULg

Book published by DEStech Publications, Inc (2010)

These proceedings contains 122 papers. The covered topics are: steel structures, concrete structures, composite structures, timber structures, connections and fire safety engineering and practice.

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See detailParametrical study on the behaviour of steel and composite cellular beams under fire conditions
Vassart, Olivier; Bailey, C. G.; Bihina, Gisèle et al

in Kodur, Venkatesh; Franssen, Jean-Marc (Eds.) Structures in Fire. Proceedings of the Sixth International Conference (2010)

This paper describes an extensive parametric study on the behaviour of cellular beam under fire conditions. Different finite element models using shell elements were developed considering both material ... [more ▼]

This paper describes an extensive parametric study on the behaviour of cellular beam under fire conditions. Different finite element models using shell elements were developed considering both material and geometrical non-linearity; CAST3M [1], ANSYS [2] and another one in SAFIR [3]. They were calibrated on the basis of a new experimental test campaign performed in the scope of the project FICEB+ [4] funded by the Research Fund for Coal and Steel. The comparison between the finite element prediction and actual experimental results showed a good agreement in terms of failure modes, load deflection relationship and ultimate loads. At failure, temperature measured during the fire tests indicated that failure arising by web post buckling of cellular beams in fire cannot be simply estimated by applying temperature dependent reduction factors on strength alone, as given in codes. A design model representing the behaviour of cellular beam in fire conditions has been developed by Vassart [5-7]. This design model is able to predict the complex behaviour of cellular beam in case of fire comprising web-post buckling and Vierendeel bending, as well as standard flexural bending. The results of the Finite Element Models are compared in terms of critical temperatures and failure mode obtained using the design model. This paper also contains some tests results that were used to calibrate the FEM model and the comparison between analytical and FEM models. [less ▲]

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See detailLateral-torsional buckling of carbon steel and stainless steel beams subjected to combined end moments and transverse loads in case of fire
Lopes, Nuno; Vila Real, Paulo; Da Silva, Luis et al

in Kodur, Venkatesh; Franssen, Jean-Marc (Eds.) Structures in Fire. Proceedings of the Sixth International Conference (2010)

This paper presents a numerical study on the behaviour of carbon steel and stainless steel I-beams subjected to lateral-torsional buckling (LTB) in case of fire. The main motivation for this work is the ... [more ▼]

This paper presents a numerical study on the behaviour of carbon steel and stainless steel I-beams subjected to lateral-torsional buckling (LTB) in case of fire. The main motivation for this work is the fact that part 1-2 of Eurocode 3 (EC3) does not take into consideration the beneficial effect, resulting from the reduction of the plastic zones connected with non-uniform bending diagrams along the beam. Although new formulae for the LTB, that approximate better the real behaviour of steel structural elements in case of fire, have been proposed in previous works, they still do not considered the combination of end moments and transverse loads, as it is stated in part 1-1 of EC3. Therefore, in this paper numerical simulations, of steel beams with combined end moments and transverse loads, are compared with the LTB design curves of EC3, and new correction factors that improve these curves are presented. [less ▲]

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See detailAssessment of Eurocode 5 charring rate calculation methods
Cachim, Paulo; Franssen, Jean-Marc ULg

in Fire Technology (2010), 46

The base hypothesis for the assessment of fire resistance of timber structures by simple calculation models is that for temperatures above 300 ºC, timber is no longer able to sustain any load ... [more ▼]

The base hypothesis for the assessment of fire resistance of timber structures by simple calculation models is that for temperatures above 300 ºC, timber is no longer able to sustain any load. Consequently, the determination of the location of the 300 ºC isotherm, the charring depth, is decisive for the result of fire resistance calculation methods. Charring rate of timber is dependent of numerous factors, such as wood species (density, permeability or composition), moisture or direction of burning (along or across the grain). Eurocode 5, Part 1-2, presents several methods for the calculation of fire resistance of timber structures that are divided into simplified and advanced. In this paper simplified and advanced methods are compared regarding the calculation of the charring depth and residual cross section strength. Finite element simulations have been performed, employing the proposed timber properties of Eurocode 5 using finite element code SAFIR. The influence of parameters such as timber density and moisture has been investigated. The results obtained with finite element calculations were then compared with Eurocode 5 simplified models. Some inconsistencies between methods have been observed. This paper presents some proposals to overcome some of the inconsistencies as well as to extend the applicability of the models. [less ▲]

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See detailFire Design of Steel Structures : Eurocode 1: Actions on structures. Part 1-2: Actions on structures exposed to fire: Eurocode 3: Design of steel structures: Part 1-2: Structural fire design
Franssen, Jean-Marc ULg; Vila Real, Paulo

Book published by Ernst & Sohn (2010)

This book explains and illustrates the rules that are given in the Eurocodes for designing steel structures subjected to fire. After the first introductory chapter, Chapter 2 explains how to calculate the ... [more ▼]

This book explains and illustrates the rules that are given in the Eurocodes for designing steel structures subjected to fire. After the first introductory chapter, Chapter 2 explains how to calculate the mechanical actions (loads) in the fire situation based on the information given in EN 1990 and EN 1991. Chapter 3 presents the models to be used to represent the thermal actions created by the fire. Chapter 4 describes the procedures to be used to calculate the temperature of the steelwork from the temperature of the compartment and Chapter 5 shows how the information given in EN 1993-1-2 is used to determine the load bearing capacity of the steel structure. The methods use to evaluate the fire resistance of bolted and welded connections are described in Chapter 7. Chapter 8 describes a computer program called ‘Elefire-EN’ which is based on the simple calculation model given in the Eurocode and allows designers to quickly and accurately calculate the performance of steel components in the fire situation. Chapter 9 looks at the issues that a designer may be faced with when assessing the fire resistance of a complete building. This is done via a case study and addresses most of the concepts presented in the earlier Chapters. Finally the annexes give basic information on the thermal and mechanical properties for both carbon steel and stainless steel. The concepts and fire engineering procedures given in the Eurocodes may seem complex to those more familiar with the prescriptive approach. This publication sets out the design process in a logical manner giving practical and helpful advice and easy to follow worked examples that will allow designers to exploit the benefits of this new approach to fire design. [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 detailFire resistance of a steel structure subjected to a localised fire
Franssen, Jean-Marc ULg; alonso, Alain

Report (2009)

The fire resistance of a light weight steel structure is analised under a localised fire.

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See detailCIMEDE : Pré-dimensionnement des solutions de plancher
Peigneux, Christophe ULg; Franssen, Jean-Marc ULg

Report (2009)

Ce présent rapport a pour but d’expliquer la démarche de dimensionnement poursuivie pour les 6 solutions de plancher retenues. Ce rapport ne fournit pas un dimensionnement exact des structures de plancher ... [more ▼]

Ce présent rapport a pour but d’expliquer la démarche de dimensionnement poursuivie pour les 6 solutions de plancher retenues. Ce rapport ne fournit pas un dimensionnement exact des structures de plancher étudiées mais fournit un pré-dimensionnement. Ce dernier a été réalisé sur base d’une série d’hypothèses permettant de simplifier le modèle de calcul. Les dimensions obtenues ne sont dès lors probablement pas les dimensions exactes des éléments structurels mais permettent d’obtenir un ordre de grandeur des dimensions et de la quantité de matériau nécessaire. Le pré-dimensionnement est effectué sur base de l’Eurocode EN 1995-1-1 pour les solutions en bois et EN 1994-1-1 pour les solutions mixtes acier-béton. L’hypothèse principale que nous effectuons est de supposer une connexion complète entre les différents éléments dans le cas d’une solution mixte (acier-béton, bois-bois, bois-acier, …). Cette hypothèse engendre comme conséquence directe que nous sous-estimons les flèches. En effet, nous négligeons le glissement qui pourrait se produire à l’interface des éléments. Pour contre à cela, nous garderons une réserve de l’ordre de 20% sur les flèches par rapport à la limite admissible. En effet, en phase de pré-dimensionnement, il n’est pas judicieux de déjà procéder au calcul des connecteurs et donc à la détermination du degré de connexion entre éléments. [less ▲]

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See detailToepassingsgebiet ontwerpsoftware
Franssen, Jean-Marc ULg

Conference given outside the academic context (2009)

This Powerpoint presentation compares the results provided by the simple calculation model and the general calculation model for the calculation of the fire resistance of simple structural members ... [more ▼]

This Powerpoint presentation compares the results provided by the simple calculation model and the general calculation model for the calculation of the fire resistance of simple structural members subjected to fire. [less ▲]

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See detailFire resistance of long span cellular beam made of rolled profiles (FICEB) report: Ulster test numerical simulation
Gernay, Thomas ULg; Franssen, Jean-Marc ULg

Report (2009)

In the Ulster fire test, a large scale composite floor using cellular beams connected to composite slabs will be tested under natural fire. The particularity of the composite floor in this test is that ... [more ▼]

In the Ulster fire test, a large scale composite floor using cellular beams connected to composite slabs will be tested under natural fire. The particularity of the composite floor in this test is that certain cellular beams will be without any fire protection in order to investigate the contribution of membrane effect to overall fire resistance. However, cellular beams could behave in a very different way compared to traditional steel beams because of risk of local phenomenon. The aim of this study was to build a complex FE Model of whole composite floor system with long span cellular beams connected to composite slab in order to take account of 3D membrane effect. This permitted, on the one hand, to find out the right numerical model for this type of composite floor, and on the other hand to define the appropriate structure to be used for the full scale fire test. In order to achieve this latter purpose, a sensitivity study has be carried out in which determinant parameters for ensuring a good membrane effect have been investigated. [less ▲]

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See detailUtilisation du bois dans la construction - Essai de résistance au feu sur un escalier en bois
Franssen, Jean-Marc ULg; Lansival, Jean-Baptiste; Wellens, Eric ULg et al

Report (2009)

A fire resistance test has been performed on a short staircase made of wood. It was made of 6 steps, 3 made of oak and 3 made of beech, all with different thicknesses. All 6 steps were loaded by mass. The ... [more ▼]

A fire resistance test has been performed on a short staircase made of wood. It was made of 6 steps, 3 made of oak and 3 made of beech, all with different thicknesses. All 6 steps were loaded by mass. The pyrolysis rate as well as the time of collapse was observed for each step. [less ▲]

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See detailStatistical report of the Egolf round-robin Nr TC2 09-1 in fire resistance testing
Dumont, Fabien ULg; Wellens, Eric ULg; Franssen, Jean-Marc ULg

Report (2009)

This document reports the statistical analysis conducted on the raw data issued from the TC2 09-1 round-robin performed by 31 Egolf fire testing laboratories. The test specimen is a gypsum plaster board ... [more ▼]

This document reports the statistical analysis conducted on the raw data issued from the TC2 09-1 round-robin performed by 31 Egolf fire testing laboratories. The test specimen is a gypsum plaster board partition tested according to EN 1364-1. [less ▲]

Detailed reference viewed: 48 (17 ULg)