Formulas: Local Buckling of Tee Stems and Double-Angle Web Legs in Flexural Compression

Equation F9-16

M_{n}=F_{c r} S_{x}

where

$\begin{aligned} S_{x} & =\text { elastic section modulus taken about the } x \text {-axis, in. }^{3}\left(\mathrm{~mm}^{3}\right) \\ F_{c r}, & \text { the critical stress, is determined as follows: }\end{aligned}$

Formula 2

(1) When $\frac{d}{t_{w}} \leq 0.84 \sqrt{\frac{E}{F_{y}}}$

\frac{d}{t_{w}} \leq 0.84 \sqrt{\frac{E}{F_{y}}}

Formula 3

(2) When $0.84 \sqrt{\frac{E}{F_{y}}} \leq \frac{d}{t_{w}} \leq 1.52 \sqrt{\frac{E}{F_{y}}}$

0.84 \sqrt{\frac{E}{F_{y}}} \leq \frac{d}{t_{w}} \leq 1.52 \sqrt{\frac{E}{F_{y}}}

Equation F9-18

F_{c r}=\left(1.43-0.515 \frac{d}{t} \sqrt{\frac{F_{y}}{E}}\right) F_{y}

Formula 5

(3) When $\frac{d}{t_{w}}>1.52 \sqrt{\frac{E}{F_{y}}}$

\frac{d}{t_{w}}>1.52 \sqrt{\frac{E}{F_{y}}}

Equation F9-19

F_{c r}=\frac{1.52 E}{\left(\frac{d}{t_{w}}\right)^{2}}

Found in

TEES AND DOUBLE ANGLES LOADED IN THE PLANE OF SYMMETRY