7x
005859
2026-08-20

Fire Resistance

When designing the fire resistance of members that need to be designed using the general method, it is necessary to enable the “Always use the equivalent member method for fire resistance design” option in the ultimate configuration.

I’m not entirely sure whether, I need to specify both the boundary conditions and the effective lengths for a correct design, or if the boundary conditions alone are sufficient. What is the correct procedure in this case? I need to design both the ultimate limit state and the fire resistance.


Answer:

If you want to perform the design using the general method and have only defined boundary conditions, you will receive an invalid design result stating that the fire resistance cannot be designed and that the effective lengths must be used.

If you enter both the effective lengths and the boundary conditions but do not select the checkbox in the configuration, you will receive an invalid analysis result because the program does not know which method to use.

If you select the checkbox, the boundary conditions will be used for the ultimate limit state, and the effective lengths will be used for the fire resistance design. This is also described in the Ultimate Configuration.


Author

Ing. Martinec takes care of customer service and student licenses in the Czech office.



;