I’m trying to model a tied arch bridge with a prestressed concrete deck as the tie. It is for hanger optimisation rather than detailed design so I’ve just simplified the deck into a concrete beam and a single steel beam acting as a tie by turning off bending and buckling if the modify element component. I have done hand calculations to determine the prestress required in the concrete and tie and converted them into an initial strain load. This should be enough to prevent the concrete going into compression but it doesn’t seem to work on Karamba. I keep getting loads of tension in the concrete tie rather than the steel taking it. Am I modelling this right?
I have attached my model below.
Network Bridge.gh (140.6 KB)
Another quick question. I have modelled my hangers as beams and removed buckling and bending capacity. I still get compression in the hangers under some load cases. is there any way of making them only carry tension, or do i just have to apply an inital strain, enough so so they can’t go into compression?