Alignment Chart vs. Approximate values of effective length factor K

[PEStruc]

Hi everyone, just trying to know when shall I use Alignment Chart vs. using the approximate values of effective length factor K shown in AICS table C-A-7.1? Appreciate your answer.

Thanks,

 

[KootK]

1) In the interest of time/fee savings, the table should be used for any situation for which it applies. Namely, members where the end restraint are fixed/pinned as opposed to rotational springs. I also don't believe that the tabulated values are any more approximate than the alignment charts. If anything, they're probable less approximate.

2) Use the alignment charts in more complex situations where the table values would not apply and one or both of your member end restraints are rightfully modelled as rotational springs rather than the more binary fix/pin.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[TehMightyEngineer]

One of my favorite lectures on this topic:

http://cloud.aisc.org/nascc/2014/140327-N40A.mp4

In short, use direct analysis.

Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries

https://www.facebook.com/AmericanConcrete/