Change search
Refine search result
1 - 33 of 33
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1. Andersson, Berit
    et al.
    Blomqvist, Per
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP Sveriges tekniska forskningsinstitut / Brandteknik, forskning (BRf ).
    Holmstedt, Göran
    Experimental study of thermal breakdown products from halogenated extinguishing agents2011In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 46, no 3, p. 104-115Article in journal (Refereed)
  • 2.
    Evegren, Franz
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Fire Research, Branddynamik.
    Wickström, Ulf
    Luleå University of Technology, Sweden.
    New approach to estimate temperatures in pre-flashover fires: Lumped heat case2015In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 72, p. 77-86Article in journal (Refereed)
    Abstract [en]

    This paper presents a model for estimating temperatures in pre-flashover fires where the fire enclosure boundaries are assumed to have lumped heat capacity. That is, thermal inertia is concentrated to one layer with uniform temperature and insulating materials are considered purely by their heat transfer resistance. The model yields a good understanding of the heat balance in a fire enclosure and was used to predict temperatures in insulated and non-insulated steel-bounded enclosures. Comparisons were made with full scale experiments and with other predictive methods, including CFD modeling with FDS and the so called MQH relationship. Input parameter values to the model were then taken from well-known literature and the heat release rateswere provided from the experiments. The fire temperature predictions of the model matched very well with experimental data. So did the FDS predictions while the original MQH relationship gave unrealistic results for the problems studied. Major benefits of using the model in comparison with CFD modeling are its readiness and simplicity as well as the negligible computation times needed. An Excel application of the presented pre-flashover fire model is available on request from the author.

  • 3.
    Gehandler, Jonatan
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    The theoretical framework of fire safety design: Reflections and alternatives2017In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226Article in journal (Refereed)
    Abstract [en]

    This article aims to contribute to discussions and reflections upon the practice and theory of fire safety design. Are we reaching the results we want by the best available means? The theoretical framework of fire safety design is today restricted by a linear design process where mainly quantitative data and methods matters. A deterministic approach to safety ignores the decision-making context and considers each objective in isolation. Alternative methods for the fire safety design could view the design work as an iterative problem solving process between the designers and the stakeholders. Then decision making theory can be applied to solve the problem. In the iterative process key objectives are identified and the problem and its solutions are being reframed, creative inherently safer (cannot fail) and fail safe (forgiving to errors) alternatives are initially aimed at. Design should further embrace a function-centred view of the human-technology-structure system. A utilitarian evaluation that includes also qualitative factors can identify the best trade-offs between conflicting objectives. With a diversity of perspectives on fire safety design, the field of fire safety will be strengthened and be able to assist a rapidly changing world.

  • 4.
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    An engineering tool to calculate heat release rates of multiple objects in underground structures2011In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 46, no 4, p. 194-203Article in journal (Refereed)
  • 5.
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Correlation between temperatues and oxygen measurements in a tunnel flow2007In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 42, no 1, p. 75-80Article in journal (Refereed)
  • 6.
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Heat release rate measurements of burning mining vehicles in an underground mine2013In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 61, p. 12-25Article in journal (Refereed)
  • 7.
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Heat release rates of multiple objects at varying distances2012In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 52, no Aug, p. 1-10Article in journal (Refereed)
  • 8.
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Temperature stratification in tunnels2012In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 48, no Febr, p. 30-37Article in journal (Refereed)
  • 9.
    Ingason, Haukur
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Li, Ying Zhen
    Erratum: The maximum ceiling gas temperature in a large tunnel fire (Fire Safety Journal (2012) 48 (38-48))2012In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 50, p. 63-Article in journal (Refereed)
  • 10.
    Ingason, Haukur
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Li, Ying Zhen
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Large scale tunnel fire tests with different types of large droplet fixed fire fighting systems2019In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 107, p. 29-43Article in journal (Refereed)
    Abstract [en]

    The paper presented the main results of large-scale fire tests with different types of fixed firefighting systems (FFFS) conducted in the Runehamar tunnel in June 2016. The background to the tests, the performance of the different systems, and conclusions regarding the efficiency of the systems were presented. The fire load consisted of 420 standardised wooden pallets and a target of 21 wooden pallets. Five of the tests were carried out with a 30 m long deluge zone delivering varying water densities using three different types of side-wall nozzles with an interval distance of 5 m. One test with 93 °C glass-bulb automatic sprinklers in the same zone was also conducted. In the five deluge tests, the detection system was simulated using thermocouples in the tunnel ceiling. The alarm was registered when the ceiling gas temperature reached 141 °C, and the system was activated manually after a delay of 4 min. The protection goal of the system was to prevent fire spread to a target positioned 5 m from the rear of the main fuel area, and to ensure that the fire did not exceed 30 MW in size. The system setups tested were found to meet these goals.

  • 11.
    Ingason, Haukur
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Li, Ying Zhen
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Spilled liquid fires in tunnels2017In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226Article in journal (Refereed)
    Abstract [en]

    The study focuses on release of liquids inside tunnels from tankers containing dangerous good. Experiments and analysis from large scale tests are presented. The tests include different leakage rates, leakage type, liquids, spillage sizes on sloping surfaces and heat release rates. Models for estimation of leakage rates, spillage sizes and heat release rates for different scenarios are presented. The results are important to use in the design of active fire protections systems in tunnels including ventilation, fixed fire-fighting and drainage systems.

  • 12.
    Ingason, Haukur
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Li, Ying Zhen
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Lönnermark, Anders
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Runehamar tunnel fire tests2015In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 71, no Jan, p. 134-149Article in journal (Refereed)
    Abstract [en]

    Five large-scale fire tests, including one pool fire test and four HGV mock-up fire tests, were carried out in the Runehamar tunnel in Norway in year 2003. New data and new analyzes are presented in this paper, together with a short summary of previous work on these tests. Heat release rate (HRR), radiation, fire spread, gas production, backside wall temperature, visibility, backlayering, fire growth rate, gas temperature, flame length, ventilation and pulsation are investigated. Simple theoretical models are developed to estimate and predict these parameters. The correlations developed can be used by engineers working on fire safety in tunnels.

  • 13.
    Ingason, Haukur
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Wickström, Ulf
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Fire Research.
    The international FORUM of fire research directors: A position paper on future actions for improvning road tunnel fire safety2006In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 41, no 2, p. 111-114Article in journal (Refereed)
  • 14.
    Lange, David
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Boström, Lars
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    A round robin study on modelling the fire resistance of a loaded steel beam2017In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 92, p. 64-76Article in journal (Refereed)
    Abstract [en]

    This paper details a round robin study of the calculated response of structures in fire. In this instance, the study is based on one of two fire tests which were conducted on steel beams in a horizontal fire resistance furnace. The two specimens in the tests were identical having come from the same cast flow. The tests were conducted according to EN 1365-3 and the steel beams had a total length 5.4 m, spanning 5.2 m. These tests also formed a part of a testing round robin, reported elsewhere. The calculations were conducted by round robin participants in two stages. In the first instance a prediction of the response was made without knowledge of the measured temperatures of the steel beam and with only the grade of steel and details of the test setup. In the second instance the participants were also given the measured elastic limit of the steel, which differed significantly from the elastic limit implied by the grade, as well as measured temperatures from the steel beam and the plate thermometers from the furnace and asked to refine their model. Statistical analysis of the round robin results are presented to illustrate the variation which arises in the results of calculations. The results of the round robin study serve to illustrate the fire research and testing community's capability for modelling this simple case as well as the uncertainty in the calculation results. The results of the calculation round robin are also compared with the testing round robin to illustrate the comparative certainty between testing and calculations.

  • 15.
    Lange, David
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Sjöström, Johan
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Mechanical response of a partially restrained column exposed to localised fires2014In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 67, no Jul, p. 82-95Article in journal (Refereed)
  • 16.
    Li, Ying Zhen
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Effect of cross section on critical velocity in longitudinally ventilated tunnel fires2017In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, p. 303-311Article in journal (Refereed)
    Abstract [en]

    Numerical and theoretical work was conducted to investigate the effect of tunnel cross section on critical velocityfor smoke control in longitudinally ventilated tunnel fires. The results show that for small fires, the criticalvelocity decreases with both the increasing tunnel height and tunnel width. For large fires, the critical velocitysignificantly increases with the increasing tunnel height but is independent of tunnel width. Differentcalculation models are compared with a focus on effect of tunnel cross section. A new correlation is proposedto account for the effect of tunnel width based on the previous model.

  • 17.
    Li, Ying Zhen
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Ingason, Haukur
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Discussions on critical velocity and critical Froude number for smoke control in tunnels with longitudinal ventilation2018In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 99, p. 22-26Article in journal (Refereed)
    Abstract [en]

    Determination of critical velocity is a key issue for smoke control in any tunnel with longitudinal ventilation. The critical Froude model using single Froude number of 4.5 has for decades been widely used in engineering applications. This value was originally used by Danziger and Kennedy and they argued that the critical Froude number obtained by Lee et al. was in a range of 4.5 and 6.7 and therefore a conservative value of 4.5 was obtained. This paper explores the validity of using single critical Froude number of 4.5 by investigating the original sources and comparing it to recent research results. It was found that the value of 4.5 obtained in the original source corresponds to a large tunnel fire and it correlates well with data from other literature within a narrow range of large fire sizes. Using this value produces a significantly lower critical velocity for a wide range of fire sizes and therefore it is not conservative. The Froude number of 6.7 obtained by Lee et al. corresponds to another Froude number with a different definition and it is therefore not comparable with the value of 4.5. It is found that the use of a single value of 4.5 for the critical Froude number is not reasonable in calculation of the critical velocity for smoke control in tunnels with longitudinal ventilation.

  • 18.
    Li, Ying Zhen
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Ingason, Haukur
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Influence of fire suppression on combustion products in tunnel fires2018In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 97, p. 96-110Article in journal (Refereed)
    Abstract [en]

    A series of model scale tunnel fire tests was carried out to investigate effects of the fire suppression system on production of key combustion products including CO and soot. The key parameters accounted for in the tests include fuel type, ventilation velocity and activation time. The results show that fire suppression indeed has influence on production of combustion products especially for cellulose fuels. In case that the fire is not effectively suppressed, e.g. when the water density is too low or activation is too late, the CO concentration and visibility could be worse than in the free-burn test. From the point of view of production of combustion products, only fire suppression systems with sufficient capability and early activation are recommended to be used in tunnels.

  • 19.
    Li, Ying Zhen
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Ingason, Haukur
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Scaling of wood pallet fires2017In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 88, p. 96-103Article in journal (Refereed)
    Abstract [en]

    §method for scaling time-resolved burning behaviors of wood pallet fires has been developed. A series of validation tests was carried out in two different scales and the time-resolved heat release rates were obtained and compared. The results show that the scaling method proposed works very well. The scaling method proposed could be applied to general wood pallets.

  • 20. Li, Ying Zhen
    et al.
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    The maximum ceiling gas temperature in a large tunnel fire2012In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 48, no Febr, p. 38-48Article in journal (Refereed)
  • 21.
    Li, Ying Zhen
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Ingason, Haukur
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Tunnel fire safety: editorial2018In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 97, p. 85-86Article in journal (Other academic)
  • 22.
    Lönnermark, Anders
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    In response to the letter: thermocouple configuration and heat transfer effects2007In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 42, no 2, p. 168-Article in journal (Refereed)
  • 23.
    Lönnermark, Anders
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Ingason, Haukur
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Li, Ying Zhen
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Kumm, Mia
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Fire development in a 1/3 train carriage mock-up2017In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 91, p. 432-440Article in journal (Refereed)
    Abstract [en]

    To study what parameters that control the initial fire spread and the development to local flashover in a metro carriage, a total of six fire tests were conducted in a mock-up of a metro carriage that is about 1/3 of a full wagon length. They were carried out under a large scale calorimeter in a laboratory environment. The focus was on the initial fire development in a corner scenario using different types of ignition source that may lead to a fully developed fire. The ignition sources used were either a wood crib placed on a corner seat or one litre of petrol poured on the corner seat and the neighbouring floor together with a backpack. The amount of luggage and wood cribs in the neighbourhood of the ignition source was continuously increased in order to identify the limits for flashover in the test-setup. The tests showed that the combustible boards on parts of the walls had a significant effect on the fire spread. In the cases where the initial fire did not exceed a range of 400–600 kW no flashover was observed. If the initial fire grew up to 700–900 kW a flashover was observed. The maximum heat release rate during a short flashover period for this test set-up was about 3.5 MW. The time to reach flashover was highly dependent on the ignition type: wood cribs or backpack and petrol. A full developed carriage fire was achieved as a result of intense radiation from the flames and ceiling smoke layer. This was mostly dependent on the amount of fire load nearby the ignition source and how strong the vertical flame spread on the high pressure laminate boards mounted to walls and ceiling above the ignition source was, leading to a ceiling flame. In such cases, the seats alone did not contain sufficient fuel for the fire to spread within the train, and additional fuel (luggage) is required near the seats. For fully developed carriage fires, the fire starting on the seat in the corner spread to the opposite seat on the same side of the aisle, then horizontally spread to seats on the other side of the aisle, and finally a longitudinal flame spread along the carriage was observed. When and where the fire stopped or whether it reached a fully developed stage was mostly dependent on the amount of fire load nearby the ignition source and how strong the vertical flame spread on the high pressure laminate boards mounted to walls and ceiling above the ignition source was.

  • 24.
    Mindykowski, Pierrick
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Jørgensen, M.
    DTU Technical University of Denmark, Denmark.
    Svensson, S.
    DTU Technical University of Denmark, Denmark; University of Borås, Sweden.
    Jomaas, G.
    DTU Technical University of Denmark, Denmark; University of Edinburgh, UK.
    A simple correlation for monitoring the ignition propensity of wet nordic spruce wood2019In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 107, p. 186-192Article in journal (Refereed)
    Abstract [en]

    A combination of cone heater experiments and asymptotic analysis was used to determine the moisture content of Nordic spruce with varying degree of drying. The fuel moisture content was measured by weighing the specimens before and after a drying procedure in an oven. A high-flux asymptotic solution from an integral model established that the ignition temperature from the experiments (directly linked to the intercept heat flux) was constant for both the dry and the moist wood. As a result, one simple equation was developed that can be used to determine the time to ignition for a piece of wet spruce from the time to ignition of dry wood. This simple correlation, combined with models giving the fuel moisture content of wood from humidity and temperature of air surrounding, can be used as an engineering equation for monitoring the ignition propensity of timber.

  • 25.
    Mäger, Katrin Nele
    et al.
    Tallinn University of Technology, Estonia.
    Just, Alar
    Tallinn University of Technology, Estonia.
    Schmid, Joachim
    ETH Zürich, Switzerland.
    Werther, Norman
    Technical University of Munich, Germany.
    Klippel, Michel
    ETH Zürich, Switzerland.
    Brandon, Daniel
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Frangi, Andrea
    ETH Zürich, Switzerland.
    Procedure for implementing new materials to the component additive method2017In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226Article in journal (Refereed)
    Abstract [en]

    The performance of light timber frame wall and floor assemblies in fire depends on their composition. The assemblies' ability to form fire-separations between building compartments (separating function) can be assessed by full-scale fire testing or calculation methods. Calculations are the low cost and more flexible alternative.The component additive method is a commonly used calculation method for fire design of timber structures. The method considers the insulation ability of the material layers present in the assembly. The component additive method described in this article is developed to be flexible to implement different materials and products of different dimensions. However, the amount of different materials currently included in this method is rather limited and there is no generally accepted procedure to implement new materials.This paper presents a common agreement of the procedure to implement new materials which comprises of: (1) the design and execution of model-scale fire tests; (2) determination of the modified thermal properties needed for simulations; (3) thermal simulations of assemblies in fire conditions; (4) development of design equations and; (5) verification by one or more full-scale fire test(s). The abovementioned steps have been clearly presented in this paper and supported by examples.

  • 26.
    Olsson, Kim
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Anderson, Johan
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Lange, David
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Uncertainty propagation in FE modelling of a fire resistance test using fractional factorial design based model reduction and deterministic sampling2017In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226Article in journal (Refereed)
    Abstract [en]

    In this paper, fractional factorial design (FFD) and deterministic sampling (DS) are applied to a finite element (FE) model of a fire resistance test of a loaded steel beam, to investigate how uncertainties are propagated through the FE model. The sought quantity was the time when the deflection of the beam exceeded 225. mm. The FFD method was used as a model reduction technique which reduced the number of uncertain parameters from 5 to 3. The DS method was compared to a reference Monte Carlo (MC) method of 1000 simulations from all 5 uncertain parameters, which was the minimum number of simulations in order for the statistical moments to converge. The combined FFD and DS method successfully computed the propagation of the mean and standard deviation in the model, compared to the MC method. Given the uncertainties in the FE model, the fractional factorial design reduced the number of simulations required in the DS method by 82%. The combined method of FFD and DS reduced the number of required simulations by 96% compared to the MC method. The DS method did not capture the tails of the probability distribution and is therefore not a suitable candidate for probabilistic evaluation of the time of failure at the edges of the domain of possible failure times. Future research could very well be on improving the tails in DS. However, the DS method provides a conservative 95% coverage interval of 6. min for the time to failure of the steel beam.

  • 27.
    Schmid, Joachim
    et al.
    ETH, Switzerland.
    Brandon, Daniel
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Werther, Norman
    Technical University of Munich, Germany.
    Klippel, Michael
    ETH, Switzerland.
    Technical note - Thermal exposure of wood in standard fire resistance tests2018In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226Article in journal (Refereed)
    Abstract [en]

    Recently, standard fire resistance testing has been questioned for combustible products. A part of the comments address the thermal boundary conditions and the different thermal exposure of combustible products in comparison to incombustibles. These comments are evaluated in this technical note.To compare heat flux measurements of combustibles and incombustible products when tested in a furnace, furnace tests were performed. The furnace was controlled by plate thermometers to follow the EN 1363/ISO 834 standard temperature-time curve. It could be proven that (a) the heat flux measurements at the specimens surface behind the plate thermometer (PT) are not higher than in front of the PT. The reason for this is most likely that no flaming combustion is possible near the surface due to the low oxygen content typically for a furnace. It could be further shown (b) that the heat flux measurements when combustibles are tested follow the trend reported in literature for incombustibles. Further, (c) that the lower burner fuel used in furnaces is due to the contribution of the specimen (ca. 30% in the presented tests) and due to the lower thermal inertia (ca. 20% in the presented tests). Finally it can be concluded that the thermal exposure of combustibles and incombustibles is equivalent in furnaces simulating a ventilation controlled fire development for a pre-defined duration.

  • 28.
    Schmid, Joachim
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Hållbar Samhällsbyggnad.
    Klippel, Michael
    Just, Alar
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Hållbar Samhällsbyggnad.
    Frangi, Andrea
    Review and analysis of fire resistance tests of timber members in bending, tension and compression with respect to the Reduced Cross-Section Method2014In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 68, p. 81-99Article in journal (Refereed)
    Abstract [en]

    The Reduced Cross-Section Method (RCSM) provides a popular method for the design of timber members exposed to fire, using an effective cross-section and mechanical properties at normal temperature. The RCSM was adopted from a single publication and was originally developed for single-span beams exposed to bending load. It has been introduced in Eurocode 5 for a large range of timber members, including columns under compression and members under tension. Recently, the applicability of the method and its extended applications were called into question on the basis of limitations and contradictions found by advanced simulations. This paper analyses a total of 153 fire resistance tests (117 members in bending, six members in compression and 30 members in tension) with respect to the RCSM. The analysis shows that (i) most of the references are of too poor quality, or are incomplete, to validate a design model, (ii) results with adequate information content showed a significant deviation from the RCSM, and (iii) that the RCSM may lead to a non-conservative design. For members in tension, results fit well with the RCSM, while significant deviations were found for members in compression. Members in bending show very large scatter. It is therefore recommended that the existing design approach inEurocode 5 should be revised in order to include the results of advanced calculations and appropriate tests.

  • 29.
    Vermina Lundström, Frida
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety. Lund University, Sweden.
    Quintiere, James G.
    University of Maryland, USA.
    van Hees, Patrick
    Lund University, Sweden.
    Analysis of extinction and sustained ignition2019In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 105, p. 51-61Article in journal (Refereed)
    Abstract [en]

    The limiting conditions for sustained burning of materials are studied experimentally using gas burners. Small pool fire configurations are examined to determine the mass flux for a sustained surface diffusion flame (fire point) and the subsequent extinction limit of that flame. The burner results are compared to material data for sustained ignition, and are found to be lower. Material reported values of a critical mass flux are disparate, and burner data show that the critical mass flux can range from about 1 to 50 g/m2s. Previous studies have indicated the results depend on the convective heat transfer coefficient and the heat of combustion of the gases, but until this work no study has been presented to systematically show these dependencies. Three porous gas burners of diameters 25, 50 and 100 mm were used with fuel gases including methane, propane, isobutene, and ethylene mixed with nitrogen to precisely change the mixture heat of combustion. Diffusion flame theory based on a critical flame temperature at extinction is used to explain and correlate data for both limits. It was found that there is no statistical difference between the sustained ignition and extinction limits. A correlation for the critical mass flux is produced with heat of combustion and fuel diameter as sole dependent variables for all the fuels except methane. The results show that no burning is possible below a heat of combustion of 3–4 kJ/g. This is consistent with the European classification system for non-combustibility where the corresponding limit is set at 2 kJ/g.

  • 30.
    Wickström, Ulf
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Fire Research.
    Letter to the Editor2006In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 41, no 6, p. 491-493Article in journal (Refereed)
    Abstract [en]

    Comments on Franssen's article on calculation of temperture in fire-exposed bare steel structures

  • 31.
    Yao, Yongzheng
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety. University of Science and Technology of China, China.
    Li, Ying Zhen
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Ingason, Haukur
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Cheng, Xudong
    University of Science and Technology of China, China.
    Scale effect of mass loss rates for pool fires in an open environment and in tunnels with wind2019In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 105, p. 41-50Article in journal (Refereed)
    Abstract [en]

    This paper investigates the influence of wind on mass loss rate per unit area (MLRPUA) of fuel-controlled pool fires both in an open environment and inside tunnels and the scale effect of pool fires is also investigated. Large pool fires with a diameter D greater than 1 m (D > 1 m) are of key concern but small pool fires (D < 1 m) are also considered for comparison. This is done by analyzing large amounts of experimental data from the literature. Results show that for small pool fires (D < 1 m) in an open environment, increasing wind speed tends to increase the MLRPUA, especially for pools with D < 0.2 m, where the MLRPUA could increase significantly with the increase of wind speed. But when small pool fires occur in tunnels, the results are more complex. When the ratio of effective tunnel height to pool diameter is less than 3, increasing wind speed tends to decrease the MLRPUA. When this ratio is greater than 3, the influence of wind on MLRPUA of pool fires in tunnels is similar to that in an open environment. The influence of wind on the MLRPUA decreases for larger pool diameters, no matter whether the pool fire occurs in an open environment or in a tunnel. For large pools with D > 1 m, the MLRPUA is not affected significantly by increasing wind speed and most likely varies within 30% for a wide range of wind speeds based on the test data collected. This influence is far less than the values concluded by previous studies based on small pool fire experiments. The outcome of this study contributes to improving the understanding of burning characteristics of pool fires under windy conditions, especially large pool fires, which are much more meaningful than small pool fires from the perspectives of fire protection engineering and fire hazard assessment.

  • 32.
    Östman, Birgit
    et al.
    Linneaus University, Sweden.
    Brandon, Daniel
    RISE - Research Institutes of Sweden, Built Environment, Building Technology.
    Frantzich, Håkan
    Lund University, Sweden.
    Fire safety engineering in timber buildings2017In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 91, p. 11-20Article in journal (Refereed)
    Abstract [en]

    The combustibility of timber is one of the main reasons that many building regulations strictly limit the use of timber as a building material. Fire safety is an important contribution to feeling safe, and an important criterion for the choice of building materials. Historically, the combustibility aspect of wood has been a disadvantage for using timber as a construction material. The main precondition for an increased use of timber in buildings is providing adequate fire safety. This paper reviews the opportunities and challenges to reach this goal by implementing Fire Safety Engineering and Performance Based Design principles.

  • 33.
    Östman, Birgit
    et al.
    Trätek..
    Tsantaridis, Lazaros
    Trätek..
    Smoke production in the cone calorimeter and the room fire test1991In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 17, p. 27-43Article in journal (Other academic)
1 - 33 of 33
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
v. 2.35.7