calculate column effective length and braced length
calculate column effective length and braced length
(OP)
Hello fellow engineers,
I have to design a ballroom using steel section
i have a little trouble calculating column effective length to calculate the axial capacity since it braced in it's weak axis using pin connected beam
and i'm not sure if the brace is stiff enough to precent LTB
for more details see attached picture below
thankyou for your anawers
I have to design a ballroom using steel section
i have a little trouble calculating column effective length to calculate the axial capacity since it braced in it's weak axis using pin connected beam
and i'm not sure if the brace is stiff enough to precent LTB
for more details see attached picture below
thankyou for your anawers






RE: calculate column effective length and braced length
The strong axis of the column is braced at 8m centers provided the end walls are deemed to be shear walls and the roof is deemed to be a diaphragm, otherwise the effective length of the column is greater than 8m and would need to be analyzed to determine its effective length.
BA
RE: calculate column effective length and braced length
So you would need true crosses made of tension rods (attached to ?? points on the other columns) or braces stiff enough to prevent movement by themselves under compression.
RE: calculate column effective length and braced length
http://www.nceng.com.au/
"Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning."
RE: calculate column effective length and braced length
If connections are pinned, k = 1.0 as column can buckle in opposite directions above and below the brace.
BA
RE: calculate column effective length and braced length
RE: calculate column effective length and braced length
What about the base and eave connection? if we were to treat it as fixed we would get K=0.7, the base you could detail as fixed and not really get a large load, the rafter to column would be harder. However if we could prove partial would you consider less than 1 for a lightly loaded column?
http://www.nceng.com.au/
"Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning."
RE: calculate column effective length and braced length
OP what system are using to resist lateral loads? Is there a moment frame in this design, or a shear wall? Make sure to consider second order leaning column effects.
RE: calculate column effective length and braced length
I thought we were talking about minor axis effective length.
For the major axis, you could detail the base as fixed, but the diagram indicates that it is pinned. Before assigning a K value to major axis buckling, we have to determine how lateral loads are carried as mentioned by LeohhardEuler above. We also have to decide whether or not the slab, together with the spandrel beams constitutes a brace for the major axis. I suspect it does but personally, I would feel more comfortable with a more direct connection between slab and column.
BA