FIRE DESIGN OF STEEL MEMBERS - Civil and Natural Resources ...

capabilities has been limited to the thermal analyses of steel beam cross sections. The
thermal properties change with temperature as programmed into the computer
package, and these vary as recommended by EC3. Refer to Section 1.6.2 for these
equations.
The analysing process of a cross section of a steel beam, through SAFIR is as follows:
Wizard/Pre-processor
In this computer package the details of the cross-section of the beam are entered in a
graphic layout, and the properties of the insulation, if appropriate, are added. The
required time step, and the type of output is requested. Other options to add or edit at
this stage are the initial temperature; integration and calculation parameters and
accuracy and re-numbering of equations time discretisation. Output can be either in
the form of temperatures of the nodes, or the average temperature of the elements at
each time step.
The pre-processor therefore, creates *.str and *.dat files which the SAFIR programme
requires for an analysis of a cross section of an element. The *.str files contains
information regarding the geometry of the cross section, the placement of the nodes
and elements and the exposed edges to the fire. The *.dat files contain the calculation
information such as the integration accuracy and length of the time step.
Types of cross sections that can be analysed include unprotected members; protected
members with up to three types of insulation, and whether the beam supports a
concrete slab. Changes to the number of elements being analysed can be made to
increase or decrease the accuracy. The user also defines the type of fire that the
element is subjected to and which faces of the element are exposed to the fire.
The wizard programme was developed by G. Ionica and Y. Vanderseipen in 1998,
under the supervision of Dr J-M. Franssen at the University of Liege. The Preprocessor
developed by John Mason has more functions including options for box
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