AD.2007-07.2.13* Update to ANSI AISC N690 1984 & 1994 Codes
Four new Stress Limit Coefficients (SLC) parameters have been added for designs per ANSI/AISC N690 1984/1994 codes.
These parameters, SFC, SFT, SMZ, and SMY, all default to 1.0 and are used to control the interaction equations in Section Q1.6 of the ANSI/AISC N690 1984/1994 codes.
Members subjected to both axial compression and bending stresses are proportioned to satisfy equation Q1.6-1a:
SFC·fa/Fa + SMY·Cmyfby/[(1 - fa/F'ey)Fby] + SMZ·Cmzfbz/[(1 - fa/F'ez)Fbz] ≤ 1.0
SFC·fa/(0.6·Fy) + SMY·fby/Fby + SMZ·fbz/Fbz ≤ 1.0
when, fa/Fa > 0.15, as per section Q1.6.1 of the code.
Otherwise, equation Q1.6-2 must be satisfied:
SFC·fa/Fa + SMY·fby/Fby + SMZ·fbz/Fbz ≤ 1.0
Members subjected to both axial tension and bending stress are proportioned to satisfy equation Q 1.6-1b:
SFT·fa/(0.6·Fy) + SMY·fby/Fby + SMZ·fbz/Fbz ≤ 1.0
Refer to D1.K.2.1 Design Process for additional information on using the ANSI N690 1984 and 1994 codes.