Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Parametric fire design – zero-strengthlayers and charring rates
In the field of fire safety engineering performance based design methods are increasingly used to demonstrate that building designs are safe. However, performance based design is not commonly used for the design of timber structures, as there are not many relevant assessment methods available (Östman et al. 2010). For assessment whether the design of a building meets certain criteria, a design fire scenario is needed. Design fires often describe the temperature throughout a fire and are often based on dimensions, ventilation conditions and the fuel load of the compartment. Parametric fires are such design fires, used for structural calculations corresponding to post-flashover fires in compartments, based on the compartment’s dimensions, ventilation openings, lining materials, and the fuel load. Eurocode 1 (EN1991-1- 2:2004) includes parametric fires. Annex A of Eurocode 5 (EN1995-1-2:2004) offers calculation methods to determine charring rates of timber under parametric fire exposure, which depend mostly on the compartment’s ventilation opening sizes. However, Annex A is not accepted for use in all European countries, as the provided charring rates are questioned. Additionally, there are some parameters missing for calculations of structures exposed to parametric fires, namely: (1) notional charring rates, which take into account an increased char depth at the corners of small crosssections and (2) zero-strength-layers, which take into account a strength reduction of uncharred but damaged wood in the structural member. This paper presents an experimental study performed to determine one-dimensional, notional charring rates and zero-strength-layers corresponding to a range of parametric fire curves.
Parametric fire design – zero-strengthlayers and charring rates
In the field of fire safety engineering performance based design methods are increasingly used to demonstrate that building designs are safe. However, performance based design is not commonly used for the design of timber structures, as there are not many relevant assessment methods available (Östman et al. 2010). For assessment whether the design of a building meets certain criteria, a design fire scenario is needed. Design fires often describe the temperature throughout a fire and are often based on dimensions, ventilation conditions and the fuel load of the compartment. Parametric fires are such design fires, used for structural calculations corresponding to post-flashover fires in compartments, based on the compartment’s dimensions, ventilation openings, lining materials, and the fuel load. Eurocode 1 (EN1991-1- 2:2004) includes parametric fires. Annex A of Eurocode 5 (EN1995-1-2:2004) offers calculation methods to determine charring rates of timber under parametric fire exposure, which depend mostly on the compartment’s ventilation opening sizes. However, Annex A is not accepted for use in all European countries, as the provided charring rates are questioned. Additionally, there are some parameters missing for calculations of structures exposed to parametric fires, namely: (1) notional charring rates, which take into account an increased char depth at the corners of small crosssections and (2) zero-strength-layers, which take into account a strength reduction of uncharred but damaged wood in the structural member. This paper presents an experimental study performed to determine one-dimensional, notional charring rates and zero-strength-layers corresponding to a range of parametric fire curves.
Parametric fire design – zero-strengthlayers and charring rates
Brandon, Daniel (Autor:in) / Just, Alar (Autor:in) / Tiso, M (Autor:in)
01.01.2017
Aufsatz (Konferenz)
Elektronische Ressource
Englisch
Notes on charring rates in wood
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Charring rates and temperature profiles of wood sections
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Charring rates and temperature profiles of wood sections
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