flat plate moments

huangyhg

flat plate moments
no hits on the aci code forum, so i thought i would toss this one in here in hopes of some response.
aci 318-05 section 13.7.7.5: "distribution of moments ... to column strips, beams, and middle strips as provided in 13.6.4, 13.6.5, and 13.6.6 shall be permitted if the requirement of 13.6.1.6 is satisfied."
aci 318 section 13.6.1.6: "for a panel with beams between supports on all sides, eq (13-2) shall be satisfied ..."  
equation (13-2) places limits on the stiffnesses of the beam/slab. for a flat plate with no beams, equation (13-2) ends up yielding 0 divided by 0.  
13.6.1.6 is silent regarding panels without beams. is it the code's intent that the distribuition coefficients in 13.6.4 do not apply to flat plates (w/o beams)?  if so, what distribution should be taken to the column and middle strips?

equation 13-2 only applies to flat slabs with beams.
for flat plates, you can use the tables in 13.6.4.  alpha f is equal to zero.
daveatkins