Hello, I'm trying to calculate a steel bridge with robot. The bridge has one span and I I would like to consider two phase construction (in my first step of the project):
1- Concrete casting on steel girder (The concrete slab is just a load on the beams, has no structural function).
2- The concrete slab becomes a structural element.
1- I modeled two longitudinal beams, connected with crossbars. I assigned the load of the concrete slab; linear load on the beams. I selected everything, and I have defined a new phase of construction [1First].
The beams are deformed by the weight of the concrete: OK.
2- I modeled the concrete slab, such as a shell element, assigning a material with a weight close to 0 (the weight of the concrete slab is taken into account by the linear load on the beams). Therefore, I selected all over again and I have defined a new phase of construction [2second].
The beams are already deformed due to the weight of the concrete at the time of concrete casting: OK.
There are tensions in the concrete slab, as if working with the beams already at the time of concrete casting!
(In reality, the concrete should be unloading on the beams deformed by the weight of the concrete casting.
Then applying, in successive stages, the distributed loads on the slab, the slab is loaded for the first time, while the beams add loads.)
How can I solve this problem?
Thank you,
Raphael
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