AISC Design Guide 25
AISC Design Guide 25
(OP)
I am analyzing an ordinary moment frame of steel using the AISC Design Guide 25. I had built extensive spreadsheets to calculate stress ratios from the AISC 9th edition, appendix F, and am now getting familiar with the new design guide. I am currently struggling to find the understanding of how this design guide would be codified in language of the IBC 2009. Should I still be using AISC 9th edition since the design guide 25 came out after the adoption of IBC 2009?
The main difference that I see in the AISC design guide 25 is the use of P-delta effects and the design guide goes into great detail using 2nd order effects and gives alternatives for using the amplified 1st order effects.
Any comment is welcome. Thanks.
The main difference that I see in the AISC design guide 25 is the use of P-delta effects and the design guide goes into great detail using 2nd order effects and gives alternatives for using the amplified 1st order effects.
Any comment is welcome. Thanks.






RE: AISC Design Guide 25
RE: AISC Design Guide 25
While I agree with you on the design guide issue, I think previous code editions gave a codified approach (the 9th edition). With that logic, I suppose I will make sure that the 9th edition works, and I will probably take the approach of employing P-delta effects in a separate calculation. The 25th design guide is very very tough to make a spreadsheet. I've got a M+P stress ratio done on 4 cuts thru a tapered section, and I'm at a very very condensed 4 page spreadsheet already.
Thanks for the comment!
RE: AISC Design Guide 25
RE: AISC Design Guide 25
"The methods contained herein are primarily interpretations
of, and extensions to, the provisions of the 2005 AISC
Specification for Structural Steel Buildings (AISC, 2005),
hereafter referred to as the AISC Specification. The recommendations
of this document apply equally to the 2010 AISC
Specification for Structural Steel Buildings, although some
section and equation numbers have changed in the 2010
AISC Specification. These recommendations are not intended
to apply to structures designed using earlier editions of
the AISC Specification."
RE: AISC Design Guide 25
1) Analysis requirements to comply with the design guide recommendations are significantly more stringent than those in older AISC codes. This includes not only P-Delta (and P-Little Delta) anlysis, but also more explicit considerations of out-of-plumbness or out-of-straightness and Stiffness reduction due to residual stress.
2) The design guide features failure modes that are never addressed in the older AISC codes. Specifically Torsional Buckling, Constrained Axis Torsional Buckling.
For these reasons, and the one Steve mentioned, I cannot see trying to make DG-25 work for 9th edition steel design.