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AISC Seismic Design Manual Ex 4.4

AISC Seismic Design Manual Ex 4.4

AISC Seismic Design Manual Ex 4.4

(OP)
I am designing OMF connections using the Seismic Design Manual, for an R > 3. The thing I'm confused about is the required shear. Section 11.2a of the Provisions states Vu or Va must be increased by the seismic load effect, E = 2[1.1RyMp]. Page 4-3 of the Manual shows the same value but in the Manual example 4.4 there is a factor of 3/2 used instead of the factor of 2. Example 4.4 is using the LRFD combination, so the LF should be 1.0 for E. Is this a misprint?
Additionally, the Provisions Section 11.2a states the req'd shear need not exceed the shear resulting from the appropriate load combinations using the amplified seismic load. If I performed an analysis in RAM using the appropriate R value and load combinations, then the Vu should be correct, no?

RE: AISC Seismic Design Manual Ex 4.4

I haven't look all that closely.  But, I think this may be a case where they are expecting the plastic hinging to form in the column rather than the beam.  

If so, then then each column with have a 1.1RyMp moment. But, half the moment from the center column will be in the beam on the left and half will be in the beam on the right.  Therefore, the total moment difference is 3/2 * 1.1*Ry*Mp.  

 

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