Steel Members with Slender Elements per AISC 360-16 with ideCAD

How does ideCAD calculate steel compression strength with slender elements according to AISC 360-16?

Symbols

A_g : Gross cross-sectional area of member
A_e : Effective area
b_e : The effective width
c₁, c₂ : Effective width imperfection adjustment factor determined from Table E7.1
D : outside diameter of round HSS
F_cr : Critical stress
F_e : Elastic buckling stress determined according to Equation E3-4,
F_el : Eelastic local buckling stress determined according to Equation E7-5
F_y : Specified minimum yield stress of the type of steel being used,
K : Effective length factor
L: Laterally unbraced length of the member
L_c : Effective length of the member, (= KL)
P_n : Nominal compressive strength, kips (N)
r: Radius of gyration
λ: Width-to-thickness ratio for the element as defined in Section B4.1
λ_r : Limiting width-to-thickness ratio as defined in Table B4.1a

Members with Slender Elements Excluding Round HSS §E7.1

This section applies to slender-element compression members.

The nominal compressive strength, P_n, is determined based on the limit states of flexural buckling, torsional buckling, and flexural-torsional buckling in interaction with local buckling.

Effective areas of the cross-section, A_e, based on reduced effective widths, b_e, d_e or h_e.

Critical stress, F_cr, is determined by limit states of Flexural Buckling or Torsional and Flexural-Torsional Buckling.

• When

• When

Round HSS §E7.2

The effective area, A_e, is determined as follows:

• When

• When