Beam web crippling check using equation J10-5b or Table 9-4

[dcceecy]

when I use equation J10-5b of AISC manual to check the beam web crippling of W16x50, Rn=140 kips (N=6", bearing length)

but when I use Table 9-4, for W16x50, R5=40.5 kips, R6=5.16, so Rn=R5+6*R6=71.16 kips. < 140 kips.

I am not sure what's the problem. Thanks.

 

[nutte]

From the table, you're getting Rn/Omega. Omega in this case equals 2. The value from your equation is simply Rn, with no Omega.