References of "Franssen, Jean-Marc"
     in
Bookmark and Share    
Full Text
See detailRecherches sur le comportement au feu des structures en bois menées à l’Université de Liège
Franssen, Jean-Marc ULg

Conference given outside the academic context (2013)

This Powerpoint presents the main experimental research works performed in the laboratory of the University of Liege on the fire resistance of timber structures. The presented topics are: timber fire ... [more ▼]

This Powerpoint presents the main experimental research works performed in the laboratory of the University of Liege on the fire resistance of timber structures. The presented topics are: timber fire resistant doors, charing rates on tropical hardwood species, fire resistance of a massive timber wall, fire resistance of timber stairway with 2 different species and 3 different stair thicknesses, fire resistance of a massive timber slab, fire resistance of 4 diffrent joints between a timber floor and a timber exterior wall and fire resistance of a box girder timber floor. [less ▲]

Detailed reference viewed: 43 (3 ULg)
Full Text
Peer Reviewed
See detailA multiaxial constitutive model for concrete in the fire situation
Gernay, Thomas ULg; Franssen, Jean-Marc ULg

in Proceedings of the 13th Fire and Materials Conference (2013, January 28)

Performance-based design in fire engineering leads to increasing demand for advanced temperature-dependent material models for the load bearing materials used in building structures. These models must be ... [more ▼]

Performance-based design in fire engineering leads to increasing demand for advanced temperature-dependent material models for the load bearing materials used in building structures. These models must be valid in natural fire situations including cooling down phase and must be sufficiently robust for complex numerical calculations such as, for example, the analysis of tensile membrane action in composite slabs. Although structural concrete is widely used in civil engineering, proper modelling of its thermo-mechanical behaviour remains a challenging issue for engineers mainly because of the complexity of the phenomena that result from the microcracking process in this material and because of the necessity to ensure the numerical robustness of the models. This paper presents a new multiaxial concrete model based on a plastic-damage formulation and developed to meet the specific requirements of structural fire engineers and researchers. The model, which incorporates an explicit term for transient creep strain and encompasses a limited number of material parameters, has been implemented in a finite element software dedicated to the nonlinear analysis of structures in fire. The paper presents a series of numerical simulations conducted to highlight the model ability to capture the main phenomena that develop in concrete under fire (permanent strains, degradation of the elastic properties, unilateral effect) as well as its ability to be used for the fire analysis of large-scale structural elements. As an example, the new concrete model is used in the numerical analysis of a full scale fire test on a composite steel-concrete slab and it is shown that the computed and measured results agree. [less ▲]

Detailed reference viewed: 182 (33 ULg)
Full Text
Peer Reviewed
See detailNumerical analysis of partially fire protected composite slabs
Zaharia, Raul; Vulcu, Christian; Vassart, Olivier et al

in Steel and Composite Structures (2013), 14(1), 21-39

The paper presents a numerical investigation, done with the computer program SAFIR, in order to obtain simpler finite element models for representing the behaviour of the partially protected composite ... [more ▼]

The paper presents a numerical investigation, done with the computer program SAFIR, in order to obtain simpler finite element models for representing the behaviour of the partially protected composite steel concrete slabs in fire situation, considering the membrane action. Appropriate understanding and modelling of the particular behaviour of composite slabs allows a safe approach, but also substantial savings on the thermal insulation that has to be applied on the underlying steel structure. The influence of some critical parameters on the behaviour and fire resistance of composite slabs such as the amount of reinforcing steel, the thickness of the slab and the edge conditions is also highlighted. The numerical models are calibrated using the results of three full scale fire tests on composite slabs that have been performed in recent years. [less ▲]

Detailed reference viewed: 170 (26 ULg)
Full Text
Peer Reviewed
See detailExperimental assessment of the effect of the real flame emissivity for steel elements engulfed into fire
Tondini, Nicola; Vassart, Olivier; Franssen, Jean-Marc ULg

in Babrauska, Vytenis; Grayson, Stephen; Hirschler, Marcelo (Eds.) et al Proceedings of the Fire and Materials 2013 Conference (2013)

This paper presents the results of an experimental campaign performed to assess the effect of the flame emissivity for steel members engulfed into fire. In detail, two sizes of circular steel tubes were ... [more ▼]

This paper presents the results of an experimental campaign performed to assess the effect of the flame emissivity for steel members engulfed into fire. In detail, two sizes of circular steel tubes were engulfed into pool fires of two different diameters. Two fuels were used and for both fuels tests without column (used as comparison with existing localised fire models) and with column were performed. The temperature of the column and of the flames were measured at different heights. The width of the flame was also measured and used to calculate the emissivity of the flame the value of which was employed in numerical simulations in order to predict the evolution of the temperature of the steel column. Comparison with numerical analyses where the recommended values of the Eurocode were used is also shown. [less ▲]

Detailed reference viewed: 37 (6 ULg)
Full Text
Peer Reviewed
See detailExperimental investigation on ferritic stainless steel columns in fire
Tondini, Nicola; Rossi, Barbara; Franssen, Jean-Marc ULg

in Fire Safety Journal (2013), 62

This paper presents the performance of EN 1.4003 ferritic stainless steel hollow section columns when exposed to fire loading. Experimental analysis of the behaviour of ferritic stainless steel structural ... [more ▼]

This paper presents the performance of EN 1.4003 ferritic stainless steel hollow section columns when exposed to fire loading. Experimental analysis of the behaviour of ferritic stainless steel structural members in fire represents a novelty. In detail, three column tests were carried out in the framework of the RFCS project named Structural Applications of Ferritic Stainless Steels (SAFSS, RFSR-CT-2010-00026). Tubular thin-walled members were considered in this study because structural applications of ferritic stainless steels generally incorporate such profiles. Three columns were tested: two square hollow sections (SHS) and a rectangular hollow section (RHS) of different length. Fire loading was applied under a constant concentrically compressive load. Identical column tests at room temperature are also reported. [less ▲]

Detailed reference viewed: 31 (5 ULg)
Full Text
Peer Reviewed
See detailExperimental and numerical investigation of high-strength steel circular columns subjected to fire
Tondini, Nicola; Hoang, Van Long ULg; Demonceau, Jean-François ULg et al

in Journal of Constructional Steel Research (2013), 80

This paper presents an experimental–numerical study on the behaviour of High Strength Steel (HSS) columns at elevated temperature, both on Circular Hollow Sections (CHS) and on a Concrete Filled Tube (CFT ... [more ▼]

This paper presents an experimental–numerical study on the behaviour of High Strength Steel (HSS) columns at elevated temperature, both on Circular Hollow Sections (CHS) and on a Concrete Filled Tube (CFT). The measured yield strength of the circular sections was in the order of 820 MPa. In detail, three HSS CHS and a HSS CFT were tested under the standard ISO fire with constant eccentric compression applied load. The evolution of temperature and deformation patterns were measured by means of a comprehensive instrumentation made of thermocouples and displacement transducers. Numerical analyses were performed and compared with experimental data by employing stress–strain relationships of carbon steel at elevated temperatures provided by the Eurocodes associated to two different sets of reduction factors: i) those provided by the Eurocodes valid up to S460 steel grades; and ii) those proposed in the literature and based on tests on HSS. [less ▲]

Detailed reference viewed: 86 (12 ULg)
Full Text
Peer Reviewed
See detailStructural fire design and optimisation of a building
Tonicello, Eric; Vassart, Olivier; Zanon, Riccardo et al

in Structural Engineering International (2012), 22(4), 541-544

The "Maison de la Paix" building will be built for the Graduate Institute of International and Development Studies in Geneva (IHEID). At its heart will be a library, numerous auditoriums and seminar rooms ... [more ▼]

The "Maison de la Paix" building will be built for the Graduate Institute of International and Development Studies in Geneva (IHEID). At its heart will be a library, numerous auditoriums and seminar rooms, and a cafeteria. A complete fire analysis has been performed to optimise the steel structures. [less ▲]

Detailed reference viewed: 112 (2 ULg)
Full Text
Peer Reviewed
See detailSimplified design method for slim floor beams exposed to fire
Cajot, Louis-Guy; Gallois, Louis; Debruyckere, Rik et al

in Proceedings of NSCC2012 (2012, September 07)

One of the most important advantages of using the slim or integrated floor beams (SFB and IFB supporting full concrete slab, precast units or steel deck composite slab) is a significant fire resistance ... [more ▼]

One of the most important advantages of using the slim or integrated floor beams (SFB and IFB supporting full concrete slab, precast units or steel deck composite slab) is a significant fire resistance. However, despite of its common use in construction, no specific simplified calculation methods for the fire resistance of IFB and SFB exist in the Eurocode. This study, based on existing calculation rules of Eurocode 4, a parametrical study using soft-ware SAFIR and fire tests results, define a set of formulas to determine the thermal field and to deduce the mechanical resistance from classical plastic design. [less ▲]

Detailed reference viewed: 80 (2 ULg)
Full Text
Peer Reviewed
See detailLarge-scale fire test of unprotected cellular beam acting in membrane action
Vassart, Olivier; Bailey, C.G.; Hawes, M. et al

in Proceedings of the Institution of Civil Engineers: Structures and Buildings (2012), 165(7), 327334

This paper describes a full scale fire test performed recently on a composite floor for analysing the possibility of tensile membrane action to develop when the unprotected steel beams in the central part ... [more ▼]

This paper describes a full scale fire test performed recently on a composite floor for analysing the possibility of tensile membrane action to develop when the unprotected steel beams in the central part of the floor are made of cellular beams. The natural fire was created by a wood crib fire load of 700 MJ/m² and the 9 x 15 m floor survived the fire that peaked at 1000°C and lasted for about 90 minutes. Blind predictions of the air temperature development by the software OZone and of the structural behaviour by the software SAFIR which proved quite satisfactory are also described. [less ▲]

Detailed reference viewed: 69 (29 ULg)
Full Text
Peer Reviewed
See detailA formulation of the Eurocode 2 concrete model at elevated temperature that includes an explicit term for transient creep
Gernay, Thomas ULg; Franssen, Jean-Marc ULg

in Fire Safety Journal (2012), 51

The first objective of this paper is to highlight the capabilities and limitations of concrete uniaxial constitutive models at elevated temperatures for thermo-mechanical behavior modeling, depending on ... [more ▼]

The first objective of this paper is to highlight the capabilities and limitations of concrete uniaxial constitutive models at elevated temperatures for thermo-mechanical behavior modeling, depending on the implicit or explicit consideration of transient creep strain in the model. The characteristics inherent to the two types of models are described and compared. It appears that one of the major limitations of implicit models concerns the unloading stiffness. Based on numerical analysis performed on loaded concrete columns subjected to natural fire, it is shown that the stress–temperature paths experienced by structural concrete are varied and complicated and that concrete material models cannot handle properly these complex situations of unsteady temperatures and stresses without explicit consideration of transient creep. The second objective of the paper is to propose a new formulation of the Eurocode 2 concrete material model that contains an explicit term for transient creep. The new model is implemented in the software SAFIR and validated against experimental data of the mechanical strain developed by concrete cylinders under different unsteady temperatures and loads. It is shown that the actual material behavior is better matched with the new explicit model than with the current implicit Eurocode 2 model. Finally, a comparison is given between experimental and computed results on a centrally loaded concrete column submitted to heating–cooling sequence. [less ▲]

Detailed reference viewed: 187 (46 ULg)
Full Text
Peer Reviewed
See detailConsideration of local instabilities in beam finite elements by means of effective constitutive laws
Franssen, Jean-Marc ULg; Cowez, Baptiste ULg

in Fontana, A; Frangi, A; Knobloch, M (Eds.) Proceedings of the 7th International Conference on Structures in Fire (2012, June 06)

In the fire situation, Bernoulli beam finite elements are the workhorse used in the general calculation model for simulating the behaviour of the structure. Such finite elements treat all sections as ... [more ▼]

In the fire situation, Bernoulli beam finite elements are the workhorse used in the general calculation model for simulating the behaviour of the structure. Such finite elements treat all sections as class 1 (stocky) sections whatever the slenderness of the plates that make the section, allowing the development of a full plastic stress distribution in the section which leads to complete plastic redistribution in the structure. This type of element is thus not adapted for modelling structures that contain slender sections of class 2, 3 or 4. This document presents a new approach to take into account local instabilities using beam finite elements. The new approach is based on an effective constitutive law of steel. The effective law is not symmetrical with respect to tension and compression because, in tension, the stress-strain relationship is not modified whereas, in compression, the stress-strain relationship is modified. [less ▲]

Detailed reference viewed: 78 (14 ULg)
Full Text
Peer Reviewed
See detailFire analysis of a new steel bridge
Tonicello, Eric; Desanghere, Sylvain; Vassart, Olivier et al

in Fontana, Mario; Frangi, Andrea; Knobloch, Markus (Eds.) Proceedings of the 7th International Conference on Structures in Fire (2012, June 06)

The new steel bridge “Hans-Wilsdorf” in Geneva is an exceptional steel structure that will drive general traffic through a main transportation axis. As the investment cost of the project is important, a ... [more ▼]

The new steel bridge “Hans-Wilsdorf” in Geneva is an exceptional steel structure that will drive general traffic through a main transportation axis. As the investment cost of the project is important, a structural fire analysis has been performed to study the sensitivity of the structure to a high temperature exposure, such as a truck in fire on the deck. This analysis will allow deciding whether a severe fire could be an unacceptable economical risk for the bridge. [less ▲]

Detailed reference viewed: 79 (4 ULg)
Full Text
Peer Reviewed
See detailDevelopment of an interface between CFD and FE software
Tondini, Nicola; Vassart, Olivier; Franssen, Jean-Marc ULg

in Fontana, Mario; Frangi, Andrea; Knobloch, Markus (Eds.) Proceedings of the 7th International Conference on Structures in Fire (2012, June 06)

The paper presents the assumptions and the issues that arise when developing an integrated modelling methodology between a Computational Fluid Dynamics (CFD) software applied to compartment fires and a ... [more ▼]

The paper presents the assumptions and the issues that arise when developing an integrated modelling methodology between a Computational Fluid Dynamics (CFD) software applied to compartment fires and a Finite Element (FE) software applied to structural systems. In particular, a weak coupling approach used to simulate a fire exposed structure by modelling the fire development in the compartment, the heat penetration in the structure and the mechanical response is described. The advantages and the disadvantages of such a technique are highlighted compared to a full coupling that conversely takes into account all mutual interactions. The favourable aspect of computing the thermal response of the structure in the FE model in order to avoid modelling the structure in the CFD model is underlined, namely a sensitive reduction of computational demand. Finally, a practical application is presented. [less ▲]

Detailed reference viewed: 87 (2 ULg)
Full Text
Peer Reviewed
See detailSimple equations for the calculation of the temperature within the cross-section of slim floor beams under ISO Fire
Zaharia, Raul; Franssen, Jean-Marc ULg

in Steel and Composite Structures (2012)

The calculation of fire resistance for a composite structural element comprises the calculation of the temperature within its cross-section and of the load bearing capacity, considering the evolution of ... [more ▼]

The calculation of fire resistance for a composite structural element comprises the calculation of the temperature within its cross-section and of the load bearing capacity, considering the evolution of the steel and concrete mechanical properties, function of the temperature. The paper proposes a method to calculate the bending capacity under ISO fire, for Slim Floor systems using asymmetric steel beams, with a wider lower flange or a narrow upper flange welded onto a half hot-rolled profile. The temperatures in the cross-section are evaluated by means of empirical formulas determined through a parametrical analysis, performed with the special purpose non-linear finite element program SAFIR. Considering these formulas, the bending capacity may be calculated, using an analytical approach to determine the plastic bending moment, for different fire resistance demands. The results obtained with this simplified method are validated through numerical analysis. [less ▲]

Detailed reference viewed: 55 (13 ULg)
Full Text
See detailBranveiligheid - Brandveiligheid en berekening van de brandwerendheid van staalconstructies voor gebouwen volgens Eurocode 3
Cajot, Louis-Guy; Debruyckere, Rik; Franssen, Jean-Marc ULg

Book published by Infosteel (2012)

Dit boek behandelt in de eerste drie hoofdstukken het onderwerp brandveiligheid en de berekening van de brandwerendheid van staalconstructies voor gebouwen volgens Eurocode 3. Hoofdstuk 1 omschrijft de ... [more ▼]

Dit boek behandelt in de eerste drie hoofdstukken het onderwerp brandveiligheid en de berekening van de brandwerendheid van staalconstructies voor gebouwen volgens Eurocode 3. Hoofdstuk 1 omschrijft de doelstellingen van brandveiligheid aan de hand van het gedrag van een brand en bespreekt de maatregelen die een ontwerper kan nemen om te voldoen aan de eisen voor brandveiligheid en de wettelijk eisen. Hoofdstuk 2 gaat over het berekenen van de brandwerendheid van een staalconstructie met betrekking tot bezwijken. Een eenvoudig berekeningsmodel volgens Eurocode 3 wordt besproken en is geschikt voor trekstaven, niet-kipgevoelige liggers, kolommen én kipgevoelige liggers. Voor de berekening van geïntegreerde liggers, zowel onbekleed als bekleed wordt een geavanceerd rekenmodel gebruikt en wordt tevens een alternatieve vereenvoudigde methode voorgesteld. Hoofdstuk 3 behandelt het onderwerp fire safety engineering; een relatief nieuw vakgebied, waarbij fysische modellen worden gebruikt om het gedrag van een brand – en het effect hiervan op bouwwerken en de gebruikers – te beschrijven. Er worden vier situaties besproken die met fire safety engineering in de praktijk al zijn te berekenen: lokale branden, compartimentsbranden (zonder én met flashover), staalconstructies die zich buiten het gebouw bevinden in de buitenlucht én het systeemgedrag van een staalconstructie. Dit laatste wordt geillustreerd aan de hand van een staalplaat-betonvloer waarbij het membraaneffect in acht wordt genomen. Hoofdstuk 4 tenslotte bevat dertien ontwerptabellen voor het eenvoudig bepalen van een aantal rekenparameters zoals de afname van de effectieve vloeigrens en de elasticiteitsmodulus, de reductiefactor op de belastingen bij brand, de profielfactoren voor I-profielen, de staaltemperatuur na een bepaalde tijd (in functie van de profielfactor) en de kritieke staaltemperatuur voor kolommen (in functie van de benuttinggraad en slankheid). [less ▲]

Detailed reference viewed: 50 (0 ULg)
Full Text
Peer Reviewed
See detailDevelopment of an interface between a CFD software and a FE software for compartment fires
Tondini, Nicola; Franssen, Jean-Marc ULg

in Costruzioni Metalliche (2012), 3

The article presents the assumptions and the issues that arise when developing an integrated modelling methodology between a Computational Fluid Dynamics (CFD) software applied to compartment fires and a ... [more ▼]

The article presents the assumptions and the issues that arise when developing an integrated modelling methodology between a Computational Fluid Dynamics (CFD) software applied to compartment fires and a Finite Element (FE) software applied to structural systems. In particular, a weak coupling methodology used to simulate a fire exposed structure by modelling the fire development in the compartment, the heat penetration in the structure and the mechanical response is described. A practical application is also shown. [less ▲]

Detailed reference viewed: 43 (1 ULg)
Full Text
Peer Reviewed
See detailHeat transfer and structural response modelling of concrete filled steel hollow section columns
Binh, Chu Thi; Dotreppe, Jean-Claude ULg; Franssen, Jean-Marc ULg

in Proc; ACOME (2012)

Numerical modelling is a very useful tool to predict the fire resistance of a structure, or to reproduce artificially what has happened during a real fire. SAFIR, a non linear computer code developed at ... [more ▼]

Numerical modelling is a very useful tool to predict the fire resistance of a structure, or to reproduce artificially what has happened during a real fire. SAFIR, a non linear computer code developed at the university of Liege-Belgium, is specifically written for modeling the behavior of structures subjected to fire. It allows a determination of the temperatures in the structure resulting from the fire and, in a subsequent analysis, determination of the successive positions of equilibrium of the structure until collapse. Ten steel hollow section columns filled with self-compacting concrete embedding another steel profile have been tested in the Fire Engineering Laboratory of the University of Liege - Belgium. SAFIR code 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 subjected to fire. [less ▲]

Detailed reference viewed: 124 (7 ULg)
Peer Reviewed
See detailTensile membrane action in composite floors subjected to fire
Franssen, Jean-Marc ULg

in Liew, J Y Richard (Ed.) Advances in steel concrete composite and hybrid structures (2012)

The essential features of composite steel concrete beams and slabs are first given for a load bearing mode in one-way bending. The essential features of the two ways acting tensile membrane action load ... [more ▼]

The essential features of composite steel concrete beams and slabs are first given for a load bearing mode in one-way bending. The essential features of the two ways acting tensile membrane action load bearing mode are then explained. Experimental tests that helped understanding and quantifying the tensile membrane action, either small scale or large scale, at room temperature or in fire condition, are summarized. Simple calculation models that have been developed for calculating the load bearing capacity of composite floor under fire are presented. Considerations are given about the requirements for numerical models aiming at simulating the behavior of composite floor systems in the fire situation are given. Finally, an application example is presented of a composite floor system designed by the author in 2007. [less ▲]

Detailed reference viewed: 139 (2 ULg)
Full Text
Peer Reviewed
See detailNumerical analysis of stainless steel beam-columns in case of fire
Lopes, Nuno; Vila Real, Paulo; Simoes da Silva, Luis et al

in Fire Safety Journal (2012), 50

Detailed reference viewed: 52 (0 ULg)
Full Text
See detailSécurite incendie - Sécurité incendie et calcul de la résistance au feu des bâtiments en acier selon l'Eurocode 3
Cajot, Louis-Guy; Debruyckere, Rik; Franssen, Jean-Marc ULg

Book published by Infosteel (2012)

Ce livre traite, dans ses trois premiers chapitres, de la sécurité incendie et du calcul de la résistance au feu des structures de bâtiments en acier selon l'Eurocode 3. Le chapitre 1 définit les ... [more ▼]

Ce livre traite, dans ses trois premiers chapitres, de la sécurité incendie et du calcul de la résistance au feu des structures de bâtiments en acier selon l'Eurocode 3. Le chapitre 1 définit les objectifs de la sécurité incendie sur la base du déroulement d'un incendie et examine les mesures que le concepteur peut prendre afin de répondre aux exigences de sécurité incendie et aux exigences réglementaires. Le chapitre 2 traite du calcul de la résistance au feu de structures en acier pour ce qui concerne le critère de capacité portante. Un modèle de calcul simple est donné dans les Eurocodes pour les éléments tendus, les colonnes et les poutres soumises ou non au déversement. Pour le calcul des poutres intégrées, qu’elles soient protégées ou non, on peut utiliser un modèle de calcul avancé, mais une méthode alternative simple est décrite dans cet ouvrage. Le chapitre 3 traite de l'ingénierie de la sécurité incendie, une discipline relativement nouvelle qui utilise les modèles physiques pour décrire le déroulement d'un incendie et ses effets sur le bâtiment et ses occupants. On évoque quatre situations qui nécessitent l’utilisation de l'ingénierie de la sécurité incendie, à savoir: les feux localisés, les feux de compartiment (avec ou sans embrasement généralisé), le cas des structures en acier situées à l'extérieur du bâtiment et celui où l’on considère le comportement d’ensemble d’une ossature. Ce dernier cas est illustré par l’étude de l’effet membranaire d’un système de plancher. Enfin, le chapitre 4 contient treize tableaux de dimensionnement qui donnent directement certains paramètres de calcul comme la réduction de la limite d’élasticité efficace, celle du module d’élasticité de l’acier, le niveau de chargement en situation d’incendie, le facteur de massiveté des sections en I, la température atteinte dans l’acier après un certain temps (pour divers valeurs de ce facteur de massiveté) et la température critique des colonnes (en fonction de leur niveau de chargement et de leur élancement). [less ▲]

Detailed reference viewed: 292 (6 ULg)