Formulas: Slender Element Members Excluding Round HSS

Formula 1

(a) When $\lambda \leq \lambda_{r} \sqrt{\frac{F_{y}}{F_{n}}}$

\lambda \leq \lambda_{r} \sqrt{\frac{F_{y}}{F_{n}}}

b_{e}=b

(b) When $\lambda>\lambda_{r} \sqrt{\frac{F_{y}}{F_{n}}}$

\lambda>\lambda_{r} \sqrt{\frac{F_{y}}{F_{n}}}

b_{e}=b\left(1-c_{1} \sqrt{\frac{F_{e l}}{F_{n}}}\right) \sqrt{\frac{F_{e l}}{F_{n}}}

F_{e l}=\left(c_{2} \frac{\kappa_{r}}{\lambda}\right) F_{y}