Beam design in RAPT
Beam design in RAPT
(OP)
I have a 2-span continuous slab supported by walls on each side and a beam in the middle. The distance between the walls is 12m.
For the beam design: do I use a slab panel width of 6m, or should I increase the panel width by 25% to 7.5m? Because I realised that the middle reaction for a 2-span continuous slab is 25% higher than that of a simply supported slab due to moment redistribution.
For the beam design: do I use a slab panel width of 6m, or should I increase the panel width by 25% to 7.5m? Because I realised that the middle reaction for a 2-span continuous slab is 25% higher than that of a simply supported slab due to moment redistribution.






RE: Beam design in RAPT
RE: Beam design in RAPT
For the beam design: would you first model the continuous slab itself with transverse beams at the supports, obtain the reactions at each support (but first take out the transverse beams so as not to double-count the self weight), and then apply the reactions as a line load to each beam?
RE: Beam design in RAPT
RE: Beam design in RAPT
RE: Beam design in RAPT
Yes, run the slab first, and use the results to design the beam.
RE: Beam design in RAPT
Yes, the best option is to do the slab design first. This will confirm the slab depths etc so you get the correct loading on the beam. You could allow for support settlement in this as asixth suggested. That would depend on the expected deflection of the beam.
Then you could determine what width of slab each beam supports and allow RAPT to calculate loads based on this, or over-ride the program calculated self-weights in the general screen, and then define your own line loads for each load case.
RE: Beam design in RAPT
RE: Beam design in RAPT
RE: Beam design in RAPT
You can use Trapezoidal Elements to model it. Void to remove the upper part of the slab to create the set down in the top over the width affected and solid to add the lower part below the slab.
For specific help on using RAPT, it would be better if you email me directly. I check email every day. I do not necessarily check eng-tips every day, especially when I am out of Australia as I am now!