In the Fire Protection Configuration dialog, you make basic settings for the fire resistance design of members and surfaces ("hot design"). Here you specify how long the objects must withstand fire exposure and which sides of the cross-section or surface are exposed to fire.
The concept of design configurations is described in the chapter Timber Design. The fire protection configurations are also adapted to the Standard you specified in the model's base data for timber design.
Members
In the Members tab, you make the settings for the fire design of members and member sets.
The design is currently limited to simple rectangular cross-sections
and circular cross-sections
. You will receive an error message for all other cross-section types.
Required fire protection duration / Exposure duration
Specify how long the members must resist fire or how long the fire exposure is effective. For some standards, options for typical requirements are offered. You can also specify the fire duration as a user-defined value.
Fire exposure
Use the check boxes to control which sides of the cross-section are exposed to fire.
For a circular cross-section
, the definition of fire exposure is not relevant, as the cross-section is reduced around its entire circumference.
The charring resulting from the fire duration and fire exposure of the cross-section leads to a residual cross-section, for which the design according to the respective standard is performed.
Surfaces
In the Surfaces tab, you make the settings for the fire design of surfaces.
Settings for Fire Design
Specify how long the surfaces must resist fire or how long the fire exposure is effective. For design according to EN 1995-1-2 [1], you can specify whether the fire occurs on a wall or a ceiling and whether a heat-resistant bonding of cross-laminated timber layers exists in each case. With heat-resistant bonding, the charring is linear. If the bonding is not heat-resistant, a stepped charring pattern is applied.
The 'Thickness for neglecting the fire-reduced layer' defines the minimum thickness of a layer for the design: The layer is only considered if its remaining thickness after charring is greater than the specified value. Thinner residual layers are not considered.
Fire exposure
Specify which side(s) of the surface are exposed to fire. The surface side 'Top (-z)' is the negative surface side (i.e., opposite to the local z-axis), the surface side 'Bottom (+z)' is the positive surface side.
Using the 'Initially protected from top/bottom' check boxes, you can specify whether the surface is protected against fire exposure by certain measures, for example, fire protection cladding in the form of gypsum plasterboards. If this is the case, specify parameters such as the failure time of the fire protection cladding. It describes from when the fire exposure becomes effective for the surface.
Standard Parameters
The Standard Parameters tab manages the standard-specific parameters.
Here you can check and, if necessary, adjust the charring rates, coefficients, or adjustment factors.
Design Situation for Fire
For design in the fire situation, a design situation type or limit state type with the designation Fire must be selected on the design side. If this is not the case, no hot design is performed! Therefore, assign the appropriate type in the Design Situations table.
If you created a design situation for the fire case in the RFEM dialog Load Cases and Combinations, the type is preset accordingly.
