Fire Design Analysis of a Steel Member (EN)

This article is also available in:
By following this tutorial step-by-step, you will learn how to perform the fire design of a steel beam using IDEA StatiCa Member. An example is a simple beam under fire exposure.

1 New project

Launch IDEA StatiCa (download the newest version) and select the Member application.

inline image in article

Create a new project by selecting the starting template as shown in the following picture. Fill in the name, select the steel grade S355, design code Eurocode, thick Fire Design checkbox, and Create project.

inline image in article

After creating a project, you can start modifying the member model.

inline image in article

To calculate the Fire design, enable this feature by clicking on the top ribbon Project button and ticking the Fire design checkbox in the information. 


inline image in article
inline image in article

2 Fire exposure

Next, right-click on Fire Exposure and then click on Add fire exposure

inline image in article

After that in Fire exposure, we can choose how temperature will be calculated either calculated according to EN 1993-1-2 – Cl. 4.2.5 or manually input a temperature for the whole model.

In this tutorial, we will use the Calculated option and consequently, we will set parameters needed for calculation such as the Fire resistant class, etc. 

inline image in article

Also, we need to set the Load properties and change the Check type to Fire Resistance. 

inline image in article

3 Fire design settings

After that, we can provide the rest of the settings for calculation. Go to the Project Settings

inline image in article

Click on the type Fire and choose Fire curve. Here you can select the Fire resistance class, Fire curve type, etc. 

For this example, select parameters according to the following image.

inline image in article

The following setting is Material degradation, where you are able to select material degradation of Steel plates, bolts, and welds according to the code

There is nothing to set, everything is preset by default as per the code of our project.

inline image in article

Next is Fire protection, here you can select whether to use fire protection or not. And the following parameters such as encasement type, thickness of fire protection, etc.

For this example select parameters according to the following picture.

inline image in article

4 Calculation results

Now we set all needed parameters, and we can start calculation.

inline image in article

There we have results and we can see the calculated Temperature of Components. Depending on the temperature, reduction coefficients of material were used, more information about this can be found here.

After that select LBA analysis and run the Calculation.

inline image in article

There are LBA calculation results. 

inline image in article

Fill the imperfection fields according to the following image. And run GMNIA calculation.

inline image in article

Here you can see the final results of the GMNIA calculation. Calculated stresses and strains with reduced material properties, according to the calculated temperature and set imperfections, are satisfactory. This means our design is safe for these conditions. 

inline image in article

5 Report 

At last, go to the tab Report. IDEA StatiCa offers a fully customizable report to print out or save in an editable format.

inline image in article

You have designed and code-checked a steel member subjected to fire exposure according to Eurocode (EN).

Sample files

Related articles

Fire design

Fire design of steel connections (22.1)

Fire design – automatic temperature calculation (23.1)