panel zone deformation

huangyhg

panel zone deformation
how to determine the contribution of panel zone deformation to overall story drift? (per "modeling requirements" sec. 1630.1.2 item 2 ubc-97, p.2-13,2-14).
thanks.

the only article i found was "panel zone effect on the strength and stiffness of steel rigid frames", by roy becker in the aisc steel journal, 1st quarter, 1975, page 19.  (rather old)
the aisc seismic provisions for structural steel buildings also mentions this in section 9.2b.b (page 9)(april 15, 1997 edition).  also see the commentary on this.
i would also be interested in whatever you can find.  
the sac study concluded that explicit modeling of panel zone deformations was not required for realistic drift calculations.  they recommend allowing frame analysis based on centerline dimensions and neglecting panel zone contributions.  order a free copy of fema 350 for further reference.