Seismic Force Distributions in SlottedWebTM Connections

1
Seismic Force Distributions in SlottedWebTM
Connections

Pu Zb Fy / lb-lp
A
B
ATC-24 Test Assembly with lb (clear span)/2
h story height ls slot length
lp plate width
Elastic-plastic Boundary
h
A
B
lp
ls
lb
Sec. A-B
T
T
Slot Lengths are typically ls lt lp lb/ 10
based upon the web hinge length (A-B) and
typically ls lt dbeam/2
Equations of Equilibrium VA VB Pu T C
Fy Aflg MA,web MB,web Pu x ls - lp
MA,flg M B,flg T x dbeam- tflg
VA
VB
MA,web
MB,web
C
C
Notes The slotted connection is kinematic so
that the connection force distributions are
independent of the moment frame interstory drift,
which increases its fatigue life. The web resists
both moment and all of the beam shear whereas the
flanges resist only moment. SSDA design
rationale, verified by ATC-24 tests and FE
analyses, proportions a shear plate thickness
that forces the beam web hinging region outboard
of the welded shear plate.