AISC / API RP 2A WSD Finite Element Interpretation

I am trying to analyze a welded structure using finite element analysis and interpret the results according to the AISC Manual of Steel Construction or API RP 2A / WSD.

I can pull out component results of a beam model and directly apply the AISC equations. The beam model, however does not accurately represent the structure. When I use a plate / shell model or solid model, the results show considerably larger, but very localized stresses, but these localized stresses exceed the allowable stresses in AISC.

I'm familiar with API RP 2RD (Riser Design) and ASME Section VII Division 2 (Unfired Pressure Vessels). Both codes describe how to check FEA results for compliance with code rules. Both codes address the issue of peak stresses and provide a flow chart for their evaluation. The AISC Manual of Steel Construction does not provide this guidance.

Is there an AISC publication or other reference material that describes the use of plate / shell and solid model results for compliance with the AISC code?

 

[prex]

ASME VIII Div.2 is for plate type structures, typically vessels.
AISC is for linear type structures, typically made out of beams.
The difference is very important: to make an example, the factor 1.5 between allowables for bending stresses and membrane stresses in Div.2 is the ratio of plastic to elastic section moduli in a rectangular cross section (the vessel wall), and you know that this ratio is much lower than 1.5 in many common beam sections.
In my opinion you need to elaborate the stresses obtained with 2D or 3D elements in order to obtain the well known stresses across a beam cross section: normal stress (the average stress across the whole cross section), bending stress (the linearly varying portion of stresses), etc.
By the way a similar elaboration is also required to use Div.2 criteria, so you should be aware of it: e.g. to obtain the bending stress across the wall you need to extract the linearly varying portion from the stress distribution. prex
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