Structural Analysis for Fire Scenarios

With this module you can conduct a structural analysis for fire scenarios based on the advanced calculation method for 2D and 3D structures. Steel, reinforced concrete, timber and composite sections are used in this analysis based on the following standards:

  • EN 1992-1-2
  • EN 1993-1-2
  • EN 1995-1-2

Additionally the following calculations are available for solid models:

  • stationary and instationary temperature distributions
  • user-defined heat sources
  • stress analysis considering the strains due to a thermal action

Structural Analysis for Fire Scenarios:

  • Any kind of section geometry
  • Steel, reinforced concrete and free materials (e.g., insulation) within a section
  • Predefined and user-defined thermal material properties
  • Standard temperature-time curve, hydrocarbon fire curve etc.
  • User-defined fire curves, different fire scenarios
  • Calculation of the temperature profile in the section via nonlinear time-step calculation
  • Heat transfer by radiation and convection in cavities
  • Temperature-dependent thermal strains and stress-strain curves
  • Nonlinear time-step calculation of the structure based on the general calculation method
  • Graphical display of the time-dependent deformations, internal forces and support reactions
  • Thermal calculation of solid models

Thermal Calculation

Time-dependent cross-section temperature
Time-dependent cross-section temperature

The temperature distributions in the sections are determined as part of a nonlinear time-step calculation.

Composite section with flame applied to three sides and with an adiabatic edge
Composite section with flame applied to three sides and with an adiabatic edge
Spun concrete column with reinforcing iron, temperature distribution after 90 min.
Spun concrete column with reinforcing iron, temperature distribution after 90 min.

Various materials such as reinforced concrete, steel or insulation can be used within a section. If necessary, user-defined curves can be specified for the thermal properties of these materials.

Section edges with fire curve
Section edges with fire curve
Heat transfer by radiation and convection in cavities
Heat transfer by radiation and convection in cavities

The requisite heat transfer conditions and fire stresses are assigned to the section edges. The unit temperature-time curve, user-defined fire curves or a constant ambient temperature can be selected in this process.

Specification of transfer conditions and fire curves

The time increment and duration can be specified by the user and then incorporated into the thermal analysis and the subsequent mechanical analysis. The result is a temperature profile for all specified times.

Time-temperature curve at a selected section point
Time-temperature curve at a selected section point

Mechanical Analysis

As part of the mechanical analysis, a nonlinear time-step calculation is performed based on the 'Advanced Calculation Method' of the EN 1992-1-2, EN 1993-1-2, EN 1995-1-2 standards.

The thermal strains and stress-strain curves in the section are determined using the temperature profiles from the thermal analysis.

Related stress-strain curves for concrete with quartz additives
Related stress-strain curves for concrete with quartz additives
Temperature and stress distribution in a reinforced concrete section
Temperature and stress distribution in a reinforced concrete section

(Example: Development of a simplified calculation method for the detection of structural fire protection in reinforced concrete cantilever columns, special research project S 008)

References

Bundesministerium für Verkehr, Innovation und Technologie (BMVIT)
(Federal Ministry of Transport, Innovation and Technology)
Brandbeständigkeit von Faser-, Stahl- und Spannbeton (Fire Resistance of Fiber, Reinforced and Prestressed Concrete).
Straßenforschung Heft 544 (Road Research Vol. 544).
BMVIT, Vienna 2004.

DIN EN 1991-1-2/NA:2010-12
Nationaler Anhang – National festgelegte Parameter –
(National Annex – Nationally Determined Parameters –)
Eurocode 1: Einwirkungen auf Tragwerke –
Teil 1-2: Allgemeine Einwirkungen - Brandeinwirkungen auf Tragwerke.
(Eurocode 1: Actions on Structures – Part 1-2: General Actions – Actions on Structures exposed to Fire)
Publisher: DIN Deutsches Institut für Normung e.V., Berlin.
Beuth Verlag, Berlin 2010.

DIN EN 1992-1-2/NA:2010-12
Nationaler Anhang – National festgelegte Parameter –
(National Annex – Nationally Determined Parameters –)
Eurocode 2: Bemessung und Konstruktion von Stahlbeton- und Spannbetontragwerken –
Teil 1-2: Allgemeine Regeln - Tragwerksbemessung für den Brandfall.
(Eurocode 2: Design of Concrete Structures – Part 1-2: General Rules – Structural Fire Design)
Publisher: DIN Deutsches Institut für Normung e.V., Berlin.
Beuth Verlag, Berlin 2010.

DIN EN 1993-1-2/NA:2010-12
Nationaler Anhang – National festgelegte Parameter –
(National Annex – Nationally Determined Parameters –)
Eurocode 3: Bemessung und Konstruktion von Stahlbauten –
Teil 1-2: Allgemeine Regeln - Tragwerksbemessung für den Brandfall.
(Eurocode 3: Design of Steel Structures – Part 1-2: General Rules – Structural Fire Design)
Publisher: DIN Deutsches Institut für Normung e.V., Berlin.
Beuth Verlag, Berlin 2010.

DIN EN 1995-1-2/NA:2010-12
Nationaler Anhang – National festgelegte Parameter –
(National Annex – Nationally Determined Parameters –)
Eurocode 5: Bemessung und Konstruktion von Holzbauten –
Teil 1-2: Allgemeine Regeln - Tragwerksbemessung für den Brandfall.
(Eurocode 5: Design of Timber Structures – Part 1-2: General Rules– Structural Fire Design)
Publisher: DIN Deutsches Institut für Normung e.V., Berlin.
Beuth Verlag, Berlin 2010.

EBA-Richtlinie
Anforderungen des Brand- und Katastrophenschutzes an den Bau und den Betrieb von Eisenbahntunneln.
(EBA-Guideline – Requirements of Fire and Disaster Prevention on Construction and Management of Railroads Tunnels)
Publisher: Eisenbahnbundesamt. Date: 1.7.2008.

EN 1991-1-2:2010
Eurocode 1: Actions on Structures –
Part 1-1: General Actions – Actions on Structures exposed to Fire
Publisher: CEN European Committee for Standardization, Brussels.
Beuth Verlag, Berlin 2010.

EN 1992-1-2:2004/AC:2008
Eurocode 2: Design of Concrete Structures – Part 1-2: General Rules – Structural Fire Design
Publisher: CEN European Committee for Standardization, Brussels.
Beuth Verlag, Berlin 2008.

EN 1993-1-2:2005/AC:2009
Eurocode 3: Design of Steel Structures – Part 1-2: General Rules – Structural Fire Design
Publisher: CEN European Committee for Standardization, Brussels.
Beuth Verlag, Berlin 2009.

EN 1995-1-2:2010
Eurocode 5: Design of Timber Structures – Part 1-2: General Rules – Structural Fire Design
Publisher: CEN European Committee for Standardization, Brussels.
Beuth Verlag, Berlin 2010.

EN 1994-1-2:2005/AC:2008
Eurocode 4: Design of composite Steel and Concrete Structures – Part 1-2: General Rules – Structural Fire Design
Publisher: CEN European Committee for Standardization, Brussels.
Beuth Verlag, Berlin 2010.

Lienhard IV, J.H.;  Lienhard V, J.H.
A Heat Transfer Textbook.
Phlogiston Press, Cambridge (Massachusetts) 2008.

Hosser, D. (Hrsg.)
Leitfaden Ingenieurmethoden des Brandschutzes, Technischer Bericht vfdb TB 04/01
(Engineering Guide for Fire Protection, Technical Report vfdb TB 04/01).
Vereinigung zur Förderung des Deutschen Brandschutzes e. V. (vfdb), Altenberge 2006.

Richter, E.
Brandschutzbemessung im Massivbau - insbesondere Stahlbetonstützen
(Fire Safety Design in Solid Constructions with Emphasis on Reinforced Concrete Columns).
Institut für Baustoffe, Massivbau und Brandschutz (iBMB),
Technische Universität Braunschweig, Braunschweig 2007.

Rubert, A.; Schaumann, P.
Tragverhalten stählerner Rahmensysteme bei Brandbeanspruchung
(Load Performance of Steel-Framed Systems Subjected to Fire).
Stahlbau 9/1985.
Ernst & Sohn Verlag, Berlin 1985.

Upmeyer, J.
Nachweis der Brandsicherheit von kammerbetonierten Verbundbauteilen über Grenzbrandlasten
(Fire Safety Check of Concrete-Encased Composite Components For Ultimate Fire Loads).
(Dissertation), Technische Universität Hannover, Hannover 2001.

Zehfuß, J.
Bemessung von Tragsystemen mehrgeschossiger Gebäude in Stahlbauweise für realistische Brandbeanspruchung
(Design of Load-Bearing Systems for Multi-Floor Buildings with Steel Construction for Realistic Fire Stress).
(Dissertation), Technische Universität Braunschweig, Braunschweig 2004.

ZTV-ING
Zusätzliche Technische Vertragsbedingungen und Richtlinien für Ingenieurbauten, Teil 5 – Tunnelbau.
(Additional Technical Contract Terms and Guidelines for Engineering Structures, Part 5 – Tunnel Construction)
Publisher: Bundesanstalt für Straßenwesen (BASt). Date: 3/2012.