Cannot define the axis of the interpolated composite cross section

[gaurav.garg]

Hello there,

i am trying to create an frame corner with recessed bar and flange. I have defined the cross section with this

’ $ Voute mit vollständigem I-Profil und untergesetztem Steg und Flansch: ******************************
$ parameter definition of the bottom web and flange.

let#s  10   $Dicke Zustatzstegblech
let#t  15   $Dicke Zusatzflansch
let#b  200  $Breite des Zusatzflansches
let#hv 510  $Höhe UK Träger bis UK Zusatzflansch außen
let#hp 300  $Höhe des Profils      $ IPE 300 = 300mm Höhe
let#tp 13.5 $Dicke des profilflansches
let#a  6.0  $Schweißnahtdicken (Summe der Kehlnähte)

let#hv2 20 $ Höhe UK Träger bis UK Zusatzflansch Vouten innen

$Voute  außen
QNR 5 MNR 1
prof 1 ipe 300  dtyp d
blec  1    0.00     #hp/2              0.00    #hp/2+#hv-#t        #s      laga 0 lage 0
blec  2    #b/2     #hp/2+#hv-#t/2     0.00    #hp/2+#hv-#t/2      #t      laga free lage 0
blec  3   -#b/2     #hp/2+#hv-#t/2     0.00    #hp/2+#hv-#t/2      #t      laga free lage 0
lnah  1    0.00     #hp/2-#tp/2        0.00    #hp/2               #a
lnah  2    0.00     #hp/2+#hv-#t/2     0.00    #hp/2+#hv-#t        #a

$Voute innen
QNR 11 MNR 1
prof 1 ipe 300 dtyp d
blec  1    0.00     #hp/2               0.00    #hp/2+#hv2-#t       #s    laga 0 lage 0
blec  2    #b/2     #hp/2+#hv2-#t/2     0.00    #hp/2+#hv2-#t/2     #t    laga free lage 0
blec  3   -#b/2     #hp/2+#hv2-#t/2     0.00    #hp/2+#hv2-#t/2     #t    laga free lage 0
lnah  1    0.00     #hp/2-#tp/2         0.00    #hp/2               #a
lnah  2    0.00     #hp/2+#hv2-#t/2     0.00    #hp/2+#hv2-#t       #a

INTE (6 10 1) 5 11 S (1/6 1/6) '   $ interpolation between CS 5 and 11 in every 1/6th distance.

This composite CS sections of an IPE300 Profile and a web and flange welded to it at the bottom. The web’s height keeps on increasing as one moves towards the frame corner.

The problem i am having is since this is an interpolated cross section, the program is connecting the geometric centre line of this composite interpolating cross section with the adjoining members. The geometric centre line by virtue of interpolation is slanted. My goal is that the axis of connection remains along the centre of the IPE profile and the geometric centre line of the composite CS. How could i do it? Thanks for the help.

This is how it looks currently.

[gaurav.garg]

this is what i am trying to create. Please ignore the variables from this refernce image.

[gaurav.garg]

this is how the CS numbers look like in WINGRAF.

[Mathew78]

As someone with extensive experience in structural engineering and SOFiSTiK software, I understand the challenges that can arise when defining the axis for interpolated composite cross-sections. This issue often stems from specific requirements within SOFiSTiK’s interpolation process.​

Key Considerations:

Axis Definition:

Ensure that an axis is properly defined in your project. Without a defined axis, parametric modeling and interpolation cannot function correctly.

Cross-Section Consistency:

When performing linear interpolation between two cross-sections, it’s crucial that both sections have identical construction. Cloning the initial cross-section and modifying it ensures structural identity, facilitating successful interpolation.

Master Cross-Section Numbering:

For interpolations using a master cross-section, assign it a number of 100 or greater. Interpolated sections will then follow sequentially.

Reference Points and Variables:

Define variable points (reference points) in the master cross-section and assign them to corresponding variables or axes. This setup is essential for accurate interpolation along an axis.

Verify that an axis is defined in your project.

Ensure cross-sections intended for interpolation are structurally identical.

Assign appropriate numbering to master and interpolated cross-sections.

Define and assign reference points and variables correctly.​

By addressing these aspects, you should be able to resolve the issue with defining the axis for interpolated composite cross-sections.​

If you need further assistance or have specific questions about your setup, feel free to provide more details.

[gaurav.garg]

Thanks for your answer. I have already read these points in sofistik handbooks as well as forums. However, i would appreciate if you know the specific answer to my question and that is how can i define a axis along the centre of the upper beam.

[OMRI2024]

I think you’re looking for something like this?

[gaurav.garg]

Yes exactly. Did you define the Voute cross section in the frame corner, separately including the I beam on the top?

[OMRI2024]

Yes, you can follow this tutorial — you’ll find all the answers to your questions
Good luck!

Abderrahman OMRI.

SOFiSTiK Tutorials 2020 – Portal Frame: Materials and cross-section (1080p | Full HD)