AISC 360-5/10 Equation F13-2 Proportioning limits

[Jorisr]

I am performing a structural analysis for an existing structure. This structure contains elements that does not fullfill the requirements set in Equation F13-2 of AISC 360-5/10. The section (vertical column) is a HE140A profile reinforced using a big strip with a cross-section 40x400mm.

Now I can not find any background information about Equation F13-2. I wonder what the concerns are when a member does not fullfill the requirements stated in this Equation? As the member is compact and we could prevent lateral torsion buckling if necessary.

Thanks for your help!

 

[Jorisr]

I have been looking further in the mean time. Now I found the following "steel quiz".

The answer to question 10 states that section H2-1 should be used when the Iyc/Iy ratio is not met. Although section H2-1 refers to section F for flexural check and section F also has the same limitation Iyc/Iy as section H1-1.

Can someone acknowlege that H2-1 can be used when the member does not fullfill the "Iyc/Iy" requirement? Ignoring F13-2 then.

Thanks again.