I am modelling a simple two span bridge with a composite deck section. The girder is Y beam with prestressed tendons.
I ran a staged construction, first applying all sections except the deck. Question: why do I get a different bending moment diagram for the girders and beams before I introduce the deck section in the staged construction simulation? The mid span moment of the beam generated by CSI bridge is consistent with my hand calculation, but the mid span moment of the girder is higher than that of the beam. I understand from CSI website that girder differs from beam in that girder forces represent the forces acting on the composite section of the beam and the deck slab.
Does CSiBridge assume a geometric property that includes the deck even though I have not yet added it to my staged construction?
It seems like it, because when I reduce the thickness of the top slab from 160mm to 16mm the girder moment reduces drastically while the beam moment does not change materially.
I have attached my CSiBridge file for your reference.
I ran a staged construction, first applying all sections except the deck. Question: why do I get a different bending moment diagram for the girders and beams before I introduce the deck section in the staged construction simulation? The mid span moment of the beam generated by CSI bridge is consistent with my hand calculation, but the mid span moment of the girder is higher than that of the beam. I understand from CSI website that girder differs from beam in that girder forces represent the forces acting on the composite section of the beam and the deck slab.
Does CSiBridge assume a geometric property that includes the deck even though I have not yet added it to my staged construction?
It seems like it, because when I reduce the thickness of the top slab from 160mm to 16mm the girder moment reduces drastically while the beam moment does not change materially.
I have attached my CSiBridge file for your reference.
