Situation $3.$

A W$12$x $81$ is used as a column. The effective length in either principal direction is $20$ft$.$ Using

A$992$ steel, determine the axial compressive strength $($ASD & LRFD$).$

Properties of WT$12\backslash$times $81$:

$A=23\mathrm{.}9in..{?}^2\frac{,}{b}ar(y)=2\mathrm{.}70in.$

$d=12\mathrm{.}5in.,I_x=293in.{?}^4$

$b_f=13\mathrm{.}0in.,I_y=221in.{?}^4$

$t_f=1\mathrm{.}22in.,J=9\mathrm{.}22in.{?}^4$

$t_w=0\mathrm{.}705in.$

$r_x=3\mathrm{.}50in.$

$r_y=3\mathrm{.}05in.$

$\frac{b_f}{2}{t}_f=5\mathrm{.}31$

$\frac{d}{t_w}=17\mathrm{.}7$