Question $2$

Using the LRFD method, select the lightest satisfactory W$-$shape section if Fy$=50$ ksi. Lateral bracing is provided at the ends only. Determine Cb $.($Answer W $14$x $61)$

$1.$ Using table $\backslash (3-10\backslash )$ in the AISC manual $($graph$).$

Select a section based on Lb and Mu effective based on $\backslash (\backslash$mathrm$\{$Cb$\}=1\backslash ).$ This needs to be modified for our calculated Cb $.$ So our new Mu effective $\backslash (=\backslash$mathrm$\{$Mu$\}/\backslash$mathrm$\{$Cb$\}\backslash )$

$2.$ Chek using Table $3-2$ of the AISC manual. we should compare $\backslash (\backslash$mathrm$\{$Lb$\},\backslash$mathrm$\{$Lp$\}\backslash ),$ and Lr $($Check the behavior of the selected section?$)$