Initial rotational stiffness of a beam with a long haunch

Do you need to calculate stiffness analysis for a beam with a long haunch?


If we use manufacturing operation Widener with triangular shape with the flange on the beam and use the real length as a length of haunch, the beginning of the haunch will be cut (it’s longer then the length of the master beam)


This solution is suitable for the Stress/Strain analysis but not for the Stiffness analysis. Let’s have a look at a better model definition for the Stiffness analysis.


Let’s create a general cross-section based on the geometry of cross-section right in front of the top flange of the column. This general cross-section could be defined in the General cross-section editor, using a few components.


After applying the general cross-section to the member, the Stiffness analysis could be performed.

IDEA StatiCa Connection provides the stiffness diagram as a visualization of results and result table with the classification of the connection according to the EN 1993-1-8.


Related articles and tutorials:

IDEA StatiCa tutorial – Stiffness analysis (EN)

How to create and use a custom cross-section

Sample projects

IDEA StatiCa tutorial – How to combine Tekla Structures and SAP2000



Stiffness analysis, member length, CBFEM, general cross-section, haunch, general cross-section editor, flange