Moments in frame corners, even though no horizontal loads?


I am running a linear analysis on a frame structure. I have no horizontal loads, but i am still getting moments in my frame corners.

First i thought it was because of second order effects, but then i realized there should be no second order effects in a linear analysis.

Does SOFiSTiK do things differently?

This is my ase code, as you can see SYST PROB line = linear analysis.


Hard to help without seeing your system.
I guess it is due to support conditions. Probably restraints cause horizontal reaction due to thrust force and it causes bending moments.

Frame that is hinged in one support and horizontal roller in the other.

Thrust force? Can you explain to me what thrust force is?

I meant horizontal reaction due to arch/frame action.
Ok, I trust there is a roller support, but how can we help if we cant see it and verify? For sure there is some mistake. No constrainst and no loads in structure you descirbed should give simple-supported beam like bending moment.

Hjallerup_bro.sofistik (293.8 KB)
Hjallerup_bro.dwg (155.9 KB)

You should be able to run the model from this.