slender column
slender column
(OP)
I am using a W27x146 for a tall column. It's web is slender for compression. However, when I go through section E7 of the AISC manual, I find that there is no reduction (Qa=1). E7.2 is kind of confusing since they don't tell you what to do when b/t is less than 1.49x(E/f)^0.5. Am I missing something here? What do you do when b/t is less than 1.49x(E/f)^0.5?






RE: slender column
RE: slender column
RE: slender column
RE: slender column
This is how I rationalized it. For a really short column, local buckling of the individual plate sections that make up the column controls. Since the column is short, you end up with a high Fcr and therefore Q<1.0. For a longer column global buckling of the section becomes more critical than local buckling and Q=1.0.
Unfortunately you have to do the calculation in order to find out what is governing the design of your column.