§8.[D] Members
§8.2 Local Buckling
Only where specifically required by the specification and footnotes to Table I-8-1 are the members checked against the limiting width to thickness rations of Table I-8-1 and AISC 360 Table B4.1.
Where applicable, Pu (LRFD) and Pa (ASD) are taken as the maximum axial tension and compression force on the member from all the selected standard provision load combinations.
The calculation of the b/t, d/t, and h/t ratios are based on the AISC 360 specification.
Note that for webs of beams in Special Moment Frames (SMF) there are some conflicting limits. The program will limit the section web to the smaller of :
and
§[D1.1b] Width-to-Thickness Limitations of Steel and Composite Sections
AISC 341-16 and AISC 341-10, members are checked against the limiting width to thickness ratios of Highly Ductile or Moderately Ductile Members of Table D1.1.
§8.3 [D1.4a] Column Strength
AISC 341-16, AISC 341-10
The amplified load combinations are utilized to calculate Pu (LRFD) and Pa (ASD).
AISC 341-05
This provision is applied to all columns, irrespective of frame type. The standard provision load combinations are utilized to calculate Pu (LRFD) and Pa (ASD).
When Pu/ϕPn > 0.4 (LRFD) or ΩcPa/Pn (ASD) the amplified seismic load combinations generated in the seismic provision mode (see 4. above) are used to determine the required compressive and tensile strength.
The limiting provisions of 8.3(2) are not applied which could result in conservative axial forces being considered in 8.3(1).