unbraced length Lb question
unbraced length Lb question
(OP)
I always thought that Lb for bending of beam is for both lateral and torsional buckling length.
In attached platform pic, Lb is the whole length of the beam?
Because the perpendicular beam will only brace the torsion but will not brace the lateral buckling?
In attached platform pic, Lb is the whole length of the beam?
Because the perpendicular beam will only brace the torsion but will not brace the lateral buckling?






RE: unbraced length Lb question
BA
RE: unbraced length Lb question
so UNT and UNB will be Lb/2, and Ly will be Lb ?
I've always used Ly = UNT = UNB and nobody has been complaining.
RE: unbraced length Lb question
I don't know how staad treats the input, so I would say that:
UNB = Ly = Lb (lateral unbraced length)
and UNT = Lb/2 (torsional unbraced length)
The fact the nobody has been complaining does not mean it is correct. Perhaps your platform deck or grating is acting as a diaphragm in which case you would be okay with your assumption.
BA