Why stress in Composit Beam isn't correct?

Hi. I create compostie beam. I draw cross-section with stage.
At stage 10. I want the concrete beam have web only.
At stage 20. I want add flange of concrete beam.
I draw Prestress System too
The cross-section axial stress at stage 10 - 19 is correct (The concrete beam have web only)
Like this

But when the stage 20 - 30. The cross-section axial stress is incorrect. Like this

Can you help me, what did i do wrong?


I am sorry, but we can’t spot flaws in your project just by looking at cross sections. This forum is made for theoretical questions about the software and not for project support.
We have created several tutorials on our web site and on our youtube channel, where we discribe the general workflow for (prestressed) bridges. First of all please read those tutorials and look into the software manuals, before you ask a questions in this forum.
Thank you.

Best regards,
Your SOFiSTiK Support Team