References of "Vassart, Olivier"
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See detailExperimental assement of the effect of the real flame emissivity for steel elements engulfed into fire
Tondini, Nicola; Vassart, Olivier; Franssen, Jean-Marc ULg

in xxx (in press)

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 ▲]

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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 ▲]

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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 ▲]

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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 ▲]

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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 ▲]

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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 ▲]

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See detailLarge-Scale Fire Test of Unprotected Cellular Beam Acting in Membrane Action
Vassart, Olivier; Bailey, C. G.; Hawes, M. et al

in Journal of Structural Fire Engineering [=JSFE] (2011), 2(4), 259-268

This paper describes a full scale fire test performed the 27th of February 2010 on a composite floor for analysing the possibility of tensile membrane action to develop when the unprotected steel beams in ... [more ▼]

This paper describes a full scale fire test performed the 27th of February 2010 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 × 15 m floor survived the fire that peaked at 1000°C and lasted for 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 ▲]

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See detailFull-scale fire test on a composite floor slab incorporating long span cellular steel beams
Nadjai, Ali; Bailey, Colin; Vassart, Olivier et al

in Structural Engineer (2011), 89(21), 18-25

As part of an international major research initiative, dealing with the behaviour of long span cellular beams in steel framed buildings under fire, a large-scale fire test incorporating 15m long cellular ... [more ▼]

As part of an international major research initiative, dealing with the behaviour of long span cellular beams in steel framed buildings under fire, a large-scale fire test incorporating 15m long cellular beams was carried out. The test incorporated unprotected secondary cellular steel beams acting compositely with the supporting floor slab. The floorplate in its entirety was designed to carry the load with unprotected beams, when subjected to a severe fire, by utilising membrane action of the floor slab. The overall structure performed very well supporting the full applied static load for the duration of the test. The unprotected cellular steel beams were subjected to distortional buckling, with only the top tee providing any support through catanary action. The test supported the assumptions adopted in the structural design approach and provided an accurate estimate of the strength of the floorplate. Comparison of the recorded time-temperature relationship of the fire with the design method presented in the Eurocodes shows that the code under-predicts the severity of the fire, although this was compensated to some extent by the conservative assumptions embedded within the structural model. [less ▲]

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See detailFRACOF: Fire resistance assessment of partially protected steel-concrete composite floors
Zanon, Riccardo; Sommavilla, Mauro; Vassart, Olivier et al

in De Luca, Antonello (Ed.) XXIII Giornate italiane della costruzione in acciaio (2011, October 12)

Large scale fire tests and observations of actual building fires have shown that the fire performance of composite steel framed buildings is much better than is indicated by fire resistance tests on ... [more ▼]

Large scale fire tests and observations of actual building fires have shown that the fire performance of composite steel framed buildings is much better than is indicated by fire resistance tests on isolated elements. This contribution presents application of a simple design method, so-called FRACOF concept, for the analysis of non sway steel framed buildings with composite floors. Starting point were the outstanding results obtained in the BRE Cardington large scale building fire test programme carried out during 1995 and 1996. The method was further validated by large-scale standard furnace tests in 2008 and 2009, as well as with natural fire tests in 2010. A recent test has also shown the possibility of application of this concept to composite floors with castellated beams. The recommendations are in line with the reliability level imposed by current design rules and are limited to structures similar to that tested. The method permits designers to spare the fire protection for the framing elements for which it is not needed by keeping the same safety requirement than traditional codes. [less ▲]

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See detailSimplified Fire Design for Slim Floor Beams
Zaharia, Raul; Duma, Diana Maria ULg; Vassart, Olivier et al

in Dunai, Laszlo (Ed.) Proceedings of the 6th European Conference on Steel and Composite Structures (2011, September 02)

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See detailSimplified method for the temperature distribution in slim floor beams
Zaharia, Raul; Duma, Diana Maria ULg; Vassart, Olivier et al

in Wald, F.; Horova, K.; Jirku, J. (Eds.) Proceedings of International Conference Applications of Structural Fire Engineering (2011, April 29)

From extensive numerical thermal simulations made with SAFIR, simple design equations have been derived that allow calculating the temperature in slim floor sections subjected to an ISO 834 fire.

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See detailFire resistance of long span cellular beam made of rolled profiles
Vassart, Olivier; Hawes, Mike; Simms, Ian et al

Report (2011)

The aim of this document is to describe the calculation methods developed to assess the resistance of simply supported cellular beams in fire conditions. This development has been made in the scope of the ... [more ▼]

The aim of this document is to describe the calculation methods developed to assess the resistance of simply supported cellular beams in fire conditions. This development has been made in the scope of the RFCS FiCEB+ [23] and in the scope of the PHD of O.Vassart [24]. This calculation procedure has been introduced in the ACB+ software available on www.arcelormittal.com/sections [23] RFS2-CT-2007-00042 : FICEB+ - Fire resistance of long span cellular beam made of rolled profiles ; March 2011 [24] O. Vassart, Analytical model for cellular beams made of hot rolled sections in case of fire, PhD Thesis, Université Blaise Pascal Clermont-Ferrand II, 2009 [less ▲]

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See detailEvaluarea rezistentei la foc a planseelor compuse protejate partial
Zaharia, Raul; Dubina, Dan; Pintea, Dan et al

Book published by Orizonturi Universitare (2011)

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See detailLarge-scale fire test of unprotected cellular beam acting in membrane action
Vassart, Olivier; Bailey, C. G.; Hawes, M. et al

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

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 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 ▲]

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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 detailRobust structures by joint ductility
Kuhlmann, Ulrike; Rolle, Lars; Jaspart, Jean-Pierre ULg et al

Report (2008)

In view of recent disasters and their immense economical and human consequences more and more focus is given not only on the safety of structures - to reduce the risk for the life of people by collapse ... [more ▼]

In view of recent disasters and their immense economical and human consequences more and more focus is given not only on the safety of structures - to reduce the risk for the life of people by collapse even under exceptional loading – but on minimizing the disastrous results and to enable a quick rebuilding and reuse. One crucial mean to achieve this aim is the design of redundant robust structures. Robustness prevents the collapse of the total structure when only parts of the structure are damaged or destroyed. To avoid progressive failure, redundant structures with inherent sufficient ductile behaviour allowing deformations when a local failure occurs, have to be built. Redundancy can be achieved by allowing force redistribution within a structural system. Therefore the single sections and joints have to be especially designed and optimized, not necessarily requiring additional fabrication costs. But until now no specific rules for robustness by ductile joints exist. The aim of the present project is to define general requirements for ductile joints as part of a structural system subjected to exceptional unforeseen loading. [less ▲]

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See detail3D simulation of Industrial Hall in case of fire. Benchmark between ABAQUS, ANSYS and SAFIR
Vassart, Olivier; Cajot, Louis-Guy; O'Connor, Marc et al

in Interflam2004 Proceedings. Fire Sciences and Engineering Conference (2004, July)

For simple storey buildings, the structural behaviour in case of fire is relevant only for the safety of the firemen. The protection of occupants and goods is a matter of fire spread, smoke propagation ... [more ▼]

For simple storey buildings, the structural behaviour in case of fire is relevant only for the safety of the firemen. The protection of occupants and goods is a matter of fire spread, smoke propagation, active fire fighting measures and evacuation facilities. Brittle failure, progressive collapse and partial failure of façades elements outwards may endanger the fire fighters and have to be avoided. In order to deal with such an objective, the simulation softwares has to cover the 3D structural behaviour including membrane and restrained effects as well as the failure mode so that post-local failure stage can be analysed. Such calculation models (ANSYS, ABAQUS and SAFIR [1]) have been compared true a benchmark. In this benchmark, two different users used ABAQUS. [less ▲]

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See detailDynamic approach of structural fire calculation with FEM software
Vassart, Olivier; Cajot, Louis-Guy; Franssen, Jean-Marc ULg et al

in Proc. 5th International Conference on Performance-Based Codes and Fire Safety Design Methods (2004)

This paper explains how the dynamic approach has been implemented in the computer software SAFIR in order to cope with temporary and local failures that occured in a step be step static analysis of ... [more ▼]

This paper explains how the dynamic approach has been implemented in the computer software SAFIR in order to cope with temporary and local failures that occured in a step be step static analysis of structures subjected to fire.By means of this recently implemented dynamic algorithm, it’s now possible to simulate the complete failure mechanism, to predict the influence of a local failure on the global behaviour of the structure and to follow eventually the progressive collapse. Therefore the resistance time is now really determined whereas in the past many numerical failure corresponding to local failure were interpreted as resistance time of the whole structure. [less ▲]

Detailed reference viewed: 63 (0 ULg)