AISC BEAM-COLUMN TABLES

[haynewp]

In the 13th Manual on page 6-5, there are beam-column selection tables based on Section H of the specification. It also describes the use of these tables on pages 6-3 and 6-4 by plugging directly into the H1 equations and checking versus unity.

What I don't see is any mention of applying the B1 amplifier according to Chapter C, or some other method of including second order effects between brace points. The comments on pages 6-3 and 6-4 basically say just check the H1 equations and that is it. I could see ignoring second order effects if the Pc/Pr ratio is low, but the comments to the tables also mention using the table values directly when Pc/Pr > 0.2.

 

[WillisV]

All moments used for any strength check should already include any magnification effects due to member slenderness or sway. Code-wise, Chapter B requires that the general analysis and design of all members meet the stability provisions of Chapter C. All tables in the manual itself assume that these magnification effects have already been applied to generate the required moments being investigated.

 

[haynewp]

In hindsight now it is obvious since "Mrx, Mry" is shown in the equations on page 6-4, which as defined by C2-1a as including second order effects.