# AISC SDM Link Nominal Shear Strength



## scande0 (Apr 2, 2016)

While working problem No. 26 of the PPI 16 Hr practice exam (2nd Ed.), I found the solution referenced finding V sub p in a table (3-1) of the Seismic Design Manual.  I have the new 2nd edition of SDM which does not have such table or anything with tabulated nominal shear values.  I did compare the value the solution found to that of AISC Table 3-2 for Vn.  This value assumes the full area of the web to the section depth.  The Vp equation (F3-1) for shear yielding uses A sub lw which discounts the thickness of each flange.   Is there such a tabulation for Vp that I am missing or was it removed from the 1st Edition SDM? Or does the solution miss reference the SCM beam Zx tables?   

I know its not much to calculate Vp as presented, but I was confused by the PPI solution that I may be missing information tabulated elsewhere.  Maybe I have already forgotten what was tabulated in AISC 13th.


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## bassplayer45 (Apr 4, 2016)

Ill look at this again when I get home, but I do remember the method for solving this changed significantly from both versions of the seismic design manual.


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## TehMightyEngineer (Apr 4, 2016)

It could be that PPI forgot to update the reference from the first seismic design manual. I have the first edition manual and I'll see if the problem makes sense using that edition.


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## Andy Lin (Apr 4, 2016)

Based on the previous versions (13th Ed Manual and 2nd Ed Seismic Design Manual), definition of Aw is different between the two books.

In the Manual, Aw = dtw [Section G2.1 under equation G2-5]

Whereas in the Seismic Design Manual, Aw = (d-2tf)tw [Section 15.2b]

I assume the new versions wouldn't be much different which explains the discrepancy you found.


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## ItzmeJ0e (Apr 5, 2016)

The question has been revised in the third edition of the PPI practice exam to reflect the changes to the Seismic Design Manual. Vp is calculated in the solution and not looked up in a table. Alw is taken as (d-2tf)tw , but the value is now given in the problem statement to avoid any ambiguity.


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