SAFIR is a computer program that models the behavior of building structures subjected to fire. The structure can be made of a 3D skeleton of linear elements such as beams and columns, in conjunction with planar elements such as slabs and walls. Volumetric elements can be used for analysis of details in the structure such as connections. Different materials such as steel, concrete, timber, aluminum, gypsum or thermally insulating products can be used separately or in combination in the model.


As an example, the picture below shows the deflections, calculated with SAFIR, of a steel structure subjected to fire (courtesy BuroHappold Engineering).

SAFIR roof deformed4


SAFIR is being developed at University of Liege by Jean-Marc Franssen and Thomas Gernay.


SAFIR resources : This page includes user guides, theoritical articles, etc.

SAFIR application exemples

SAFIR user community and references


Free demonstration version

How to buy the complete version?



Take a look at a general presentation of SAFIR capabilities.



The gas temperatures produced by fire must be entered as input data in the program (some time-temperature curves recommended in international standards are proposed).


From these gas temperatures, SAFIR will first calculate the evolution of the temperatures in the structure. The structure can be made of different materials such as steel, concrete, timber, aluminum, gypsum or thermally insulating products, used separately or in combinations. These temperatures are stored in different files.


As an example, the video below shows the temperature evolution in a steel section HEB300 filled with concrete (courtesy eca-vaud).




The mechanical behavior of the structure is then calculated on the basis of its geometry, its support conditions, the loads that it must withstand and the strength of the materials, taking into account the progressive increase of temperature. The elevation of temperature in the materials produces thermal elongations together with a reduction of strength and stiffness. As a consequence, the displacements of the structure increase continuously during the course of the fire until collapse.


As an example, the video below shows the behavior of a composite steel concrete structure subjected to fire until collapse of one of the column (courtesy eca-vaud).




The main references about SAFIR are:

- Franssen, J.M., Gernay, T. (2017), Modeling structures in fire with SAFIR®: Theoretical background and capabilities, Journal of Structural Fire Engineering, 8(3):300-323.

- Franssen, J.M. (2005), “SAFIR: A thermal-structural program for modelling structures under fire”, Engineering Journal, 143–158.


You can also take a look at our Publications page.


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