Fundamental Specifications for Steel Construction/Compression

Flexural Buckling

• $P_n=F_n{A}_e$

For $F_y/F_e\le 2.25$

• $F_n=(0.658$^($F_y/F_e$))$F_y$

For $F_y/F_e>2.25$

• $F_n=0.877F_e$

Sections Not Subject to Torsional or Torsional-Flexural Buckling

• $F_e$ = π²E/(KL/r)²

Definitions

• $F_{c}r$ = flexural buckling stress (ksi, MPa)
• $F_e$ = elastick buckling stress (ksi, MPa)
• $F_y$ = specified minimum yield stress (ksi, MPa)
• $F_u$ = specified minimum tensile strength (ksi, MPa)
• $A_g$ = gross area of cross section (in², mm²)
• $A_e$ = effective net area of cross section, as reduced for holes and/or local buckling effects (in², mm²)