Formulas: Flange Local Buckling

Formula 1

$\lambda_{p f}=\lambda_{p}$ , the limiting width-to-thickness ratio for a compact flange as defined in Table B4.1b

\lambda_{p f}=\lambda_{p}

$\lambda_{r f}=\lambda_{r}$ , the limiting width-to-thickness ratio for a noncompact flange as defined in Table B4.1b

\lambda_{r f}=\lambda_{r}

M_{n}=F_{y} S_{e}

where

$S_{e}=$ effective section modulus determined with the effective width, $b_{e}$ , of the compression flange taken as follows:

b_{e}=1.92 t_{f} \sqrt{\frac{E}{F_{y}}}\left(1-\frac{0.38}{b / t_{f}} \sqrt{\frac{E}{F_{y}}}\right) \leq b

b_{e}=1.92 t_{f} \sqrt{\frac{E}{F_{y}}}\left(1-\frac{0.34}{b / t_{f}} \sqrt{\frac{E}{F_{y}}}\right) \leq b