| 1. |
- Menkveld, Albert J., et al.
(författare)
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Nonstandard Errors
- 2024
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Ingår i: JOURNAL OF FINANCE. - : Wiley-Blackwell. - 0022-1082 .- 1540-6261. ; 79:3, s. 2339-2390
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Tidskriftsartikel (refereegranskat)abstract
- In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty-nonstandard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for more reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants.
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| 2. |
- Filkov, Alexander I., et al.
(författare)
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A review of thermal exposure and fire spread mechanisms in large outdoor fires and the built environment
- 2023
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Ingår i: Fire safety journal. - : Elsevier. - 0379-7112 .- 1873-7226. ; 140
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Forskningsöversikt (refereegranskat)abstract
- Due to socio-economic and climatic changes around the world, large outdoor fires in the built environment have become one of the global issues that threaten billions of people. The devastating effects of them are indicative of weaknesses in existing building codes and standard testing methodologies. This is due in part to our limited understanding of large outdoor fire exposures, including the ones from wildland to communities and within communities. To address this problem, the Ignition Resistance Committee (IRC) of the International Association of the Fire Safety Science working group ‘Large Outdoor Fires and the Built Environment’ was established. This manuscript is the result of one of the IRC's initiatives to review current knowledge on exposures associated with large outdoor fires, identify existing knowledge gaps, and provide recommendations for future research. The article consists of two sections: the wildland fire exposure to the built environment and the settlement fire exposure to structures. Each section presents a comprehensive review of experimental and numerical studies of exposure mechanisms (flame contact and convection, radiation, and firebrands). The review concludes with a discussion on data consistency and existing knowledge gaps to highlight future directions for each of the three fire exposure mechanisms.
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| 3. |
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| 4. |
- Lange, David, et al.
(författare)
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The Tisova fire test part 1: test report
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report is a summary of the Tisova fire test, conducted in the Czech Republicin January 2015. It is the first of two reports into these test, and describes thebuilding, the experimental setup and discusses the results obtained on the day ofthe test. The results are discussed with a specific focus on the travelling nature ofthe fire in the building, since one of the objectives of the test was to provide anexperimental data set for validation of traveling fire models. To this end theproject was partially successful, since as is discussed a number of factorscontributed to slow fire spread and the need to alter the conditions of the testwhile it was ongoing by adding a mixture of diesel and gasoline to part of the fuelbed. This was needed in order to ensure that the test fulfilled the second of itsmain objectives – to provide a dataset of the response of a real structure exposedto a structurally challenging fire for the purposes of carrying out a round robinexercise of the response. This round robin will be reported in the second of thisreport series.Key conclusions from the test were that while we observed a travelling fire, thefire dynamics which lead to this and which contribute to the evolution of such afire need to be better understood.
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| 5. |
- Lange, David, et al.
(författare)
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The Tisova fire test part 2: heat transfer analysis
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report is the second of two reports into the Tisova fire test. It compares the results of three different groups’ attempts to model the temperature response of the structure in Tisova which was subject to a large scale travelling fire test. Generally it is observed that the different approaches have relatively close results, although one shows systematically hotter temperatures closer to the heated surface than the others; and differences between all three increase further from the heated surface.A comparison between the average calculated results and the experimental results is also shown for illustration. While an absolute comparison is not attempted because of experimental errors present the results do show the possible need for further data to support the heat transfer analysis required to carry out structural design for travelling fires.
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| 6. |
- Rush, David, et al.
(författare)
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Effects of a travelling fire on a concrete column - Tisova fire test
- 2015
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Ingår i: Applications of Structural Fire Engineering. - : Czech Technical University in Prague - Central Library. - 2336-7318. - 9788001061947
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Konferensbidrag (refereegranskat)abstract
- The Tisova Fire Test was a large fire test conducted in the Czech Republic in January 2015 inside of a 4-storey concrete frame building, with concrete and composite deck floors. The test compartment was on the ground floor and the fire compartment had a total area of ca. 230m2 with a height of 4.4m. The fire compartment included four columns from the original 1958 concrete construction, one of which was instrumented for temperatures, chosen due to its higher likelihood of observable structural response both during and after the fire. This paper presents selected results of the test, concentrating on the thermal environment around the column showing the variability of temperatures through the compartment height. The paper also present the columns thermal response, as well as a post-fire assessments of the columns visual condition.
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| 7. |
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| 8. |
- Rush, David, et al.
(författare)
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Towards a fragility assessment of a concrete column exposed to a real fire – Tisova Fire Test
- 2017
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Ingår i: Engineering structures. - : Elsevier BV. - 0141-0296 .- 1873-7323. ; 150, s. 537-549
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Tidskriftsartikel (refereegranskat)abstract
- Fires can cause substantial damage to structures, both non-structural and structural, with economic losses of almost 1% GDP in developed countries. Whilst design codes allow engineers to design for the primary design driver, property protection is rarely, if ever, designed for. Quantification and design around property protection has been used for some time in the seismic community, particularly the PEER framework and fragility analyses. Fragility concepts have now started to be researched predominantly for steel-composite structures, however, there has been little to no research into the quantification of property protection for concrete structures, whether in design or in post-fire assessments of fire damaged structures. This paper presents selected results from the thermal environment around, and the thermal response of, a concrete column from a large scale structural fire test conducted in Tisova, Czech Republic, inside a four-storey concrete frame building, with concrete and composite deck floors. From the results of the fire test, assessments of the fire intensity are made and used to model the potential thermal profiles within the concrete column and the implications that high temperature might have on the post-fire response of the concrete column. These thermal profiles are then used to assess the reduction of the columns cross-sectional area and are compared to a quantified damage scale for concrete columns exposed to fire. This analyses presented herein will also show that common methods of defining fire intensity through equivalent fire durations do not appropriately account for the complexities of the thermal and structural response of concrete columns exposed to a travelling fire
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| 9. |
- Anderson, Johan, et al.
(författare)
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FDS SIMULATIONS AND MODELLING EFFORTS OF TRAVELLING FIRES IN A LARGE ELONGATED COMPARTMENT
- 2019
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Ingår i: Interflam 2019, proceedings. - : Interscience Communications. ; , s. 2085-
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Konferensbidrag (refereegranskat)abstract
- The present paper investigates a travelling fire scenario in an elongated structure (Length 18 m x width 6 m x height 3 m) with a controlled fire source of six pans filled with diesel (width 4 m x length 0.5 m). The fire spread is controlled manually by initiating fires subsequently in the pools. Fire Dynamics Simulator (FDS) is used to a-priori investigate variations in geometry, material data and fire load whereas simulations using the final design were performed after the test. The input to the model beside fire source and geometry are thermal material data. The FDS simulation were used to determine the appropriate size of the downstands (2 m from the ceiling in the final design) on the side to create a sufficiently one-dimensional fire spread. The post test simulations indicate that although there are a lot of variations not included in the model similar results were obtained as in the test.
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| 10. |
- Anderson, Johan, et al.
(författare)
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FDS simulations and modelling efforts of travelling fires in a large elongated compartment
- 2021
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Ingår i: Fire and Materials. - : John Wiley and Sons Ltd. - 0308-0501 .- 1099-1018. ; 45:6, s. 699-
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Tidskriftsartikel (refereegranskat)abstract
- The present paper investigates a travelling fire scenario in an elongated structure (Length 18 m × width 6 m × height 3 m) with a controlled fire source of six trays filled with diesel (width 4 m × length 0.5 m). The fire spread is controlled manually by initiating fires consecutively in the pools. Fire dynamics simulator (FDS) is used to a-priori investigate variations in geometry, material data and fire load, whereas simulations using the final design and measured heat release rates (HRR) were performed after the test. The input to the model beside fire source and geometry are thermal material data. The FDS simulations were used to determine the appropriate size of the downstands (2 m from the ceiling in the final design) on the side to create a sufficiently one-dimensional fire spread. The post-test simulations indicate that although there are a lot of variations not included in the model similar results were obtained as in the test.
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