Thicker Flange Steel Beam
Thicker Flange Steel Beam
(OP)
A steel beam that has a steel plate welded to one of the flanges would have two different Sx. If used as a simply supported beam, would you put the thickened flange on the top (comp) or the bottom (tension). Does one of those orientations allow you to use the larger section modulus when calculating bending stress, or are you stuck using the smaller of the two Sx?
With the thickened flange, there is only one Ix for the deflection calculation so it shouldn't matter if the thickened flange is on the top or the bottom.
Assume that unbraced length is not a problem and it is just a beam (no concrete slab on top for compression).
Any help will be greatly appreciated.
Thanks
With the thickened flange, there is only one Ix for the deflection calculation so it shouldn't matter if the thickened flange is on the top or the bottom.
Assume that unbraced length is not a problem and it is just a beam (no concrete slab on top for compression).
Any help will be greatly appreciated.
Thanks






RE: Thicker Flange Steel Beam
RE: Thicker Flange Steel Beam
keep in mind that the allowable stress of the plate may be lower than the beam.
csd
RE: Thicker Flange Steel Beam
It all depends on how you want to work the problem and what you are interested in investigating.
RE: Thicker Flange Steel Beam
If its a 50ksi beam and 36ksi steel you could get the critical stress being in the plate rather then the beam flange.
csd
RE: Thicker Flange Steel Beam
IF
1. The plate is added in the field and,
2. The plate is wider than the beam flange.
This is because overhead welding is more difficult.
If the plate is narrower than the beam flange, then putting it on the top would make the welding easier.
If LTB is and issue:
I'd agree with UcfSE and put it on the top to minimize LTB buckling.
RE: Thicker Flange Steel Beam
Mike McCann
McCann Engineering
RE: Thicker Flange Steel Beam
RE: Thicker Flange Steel Beam
RE: Thicker Flange Steel Beam
Mike McCann
McCann Engineering
RE: Thicker Flange Steel Beam
RE: Thicker Flange Steel Beam
RE: Thicker Flange Steel Beam
not completely true. Local buckling of the plate must still be checked. He says unbraced length is not an issue, but it doesn't sound like it necessarily has zero unbraced length.