Stiffness analysis (EN)

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This tutorial shows how to use IDEA StatiCa Connection to model, design and check a structural steel joint and calculate the stiffness of the connection.

1 New project

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

Create a new project by selecting the starting template closest to the desired design. Fill the name and choose Eurocode as the design code and the steel grade as S235.

Stiffness analysis (EN)

2 Geometry

Three members were automatically created.

Stiffness analysis (EN)

3 Load effects

One load effect was automatically generated. Change the values of internal forces in the chart.

Stiffness analysis (EN)

4 Design

Now define a set of manufacturing operations to model the complete connection. Start with the mouse right-click at the Operations in the tree in the 3D scene. Add a New operation.

Stiffness analysis (EN)

In dialog with all available manufacturing operations, choose the End plate operation.

Stiffness analysis (EN)

Select the desired bolt grade and size (M20 10.9).

Stiffness analysis (EN)

Define the right properties of the created end plate.

Stiffness analysis (EN)

Copy operation EP1: mouse right-click at the EP1 and select Copy.

Stiffness analysis (EN)

Change the member related to EP2.

Stiffness analysis (EN)

Add the Stiffener operation to the design.

Stiffness analysis (EN)
Stiffness analysis (EN)

Modify the STIFF1 operation.

Stiffness analysis (EN)

The design is complete.

Stiffness analysis (EN)

5 Stress/strain analysis

To have the complete picture of the connection behavior, the stress/strain analysis is run first.

Select Calculate in the ribbon to run the analysis based on the CBFEM method. The numerical model is automatically generated, the calculation is performed and you can directly see the overall check results in the top-left corner of the scene.

Stiffness analysis (EN)

More detailed results can be displayed in the Check tab: activate the Strain check, Bolt forces, Mesh and Deformed shape of the connection in the ribbon to get a full picture of what is happening in the joint. 

Stiffness analysis (EN)

To keep these results, copy this project item. 

6 Stiffness analysis

To keep the stress/strain results, copy this project item. 

In the copied project item, change the analysis type to Stiffness (ST) in the top ribbon.

Verify that beam B1 is set as an Analysed member as shown below. (If you want switch Analysed member, you can use right mouse button and set another member as an Analysed member).

The “Theoretical length for My, Mz” can be set for the analyzed member. For more information about the theoretical length, please see Theoretical background and Video – tips for stiffness analysis.

Stiffness analysis (EN)

Start the stiffness analysis by the Calculate button in the top ribbon. 

The result of the analysis and the load path can be checked in detail in the Rotational stiffness tab. For a better understanding of the results, see the Theoretical Background.

Stiffness analysis (EN)

7 Modification of connection

To keep the project CON2, copy it and create CON3.

Modify endplate EP1 to increase the rigidity of the connection CON3.

Stiffness analysis (EN)

Run the stiffness analysis again. You can notice the change in classification of the connection rigidity from Semi-rigid to Rigid.

Stiffness analysis (EN)

For more information on stiffness analysis, please check out our Theoretical background and video.

8 Report

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

Stiffness analysis (EN)

You have performed a stiffness analysis of a structural steel joint according to Eurocode (EN).

9 More information

Video – introduction to stiffness

Video – tips for stiffness analysis

For more information, please visit our Theoretical background.

Sample files

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