My in table B4.1 11

[ishvaaag]

For singly symmetrical double tees, a My is required to establish landa_p, I am asking if this My -as normally would be considered be the case- needs be the moment at which the section first reaches yield, i.e., the lesser of Myc=|Sxc·Fy| or Myt=|Sxt·Fy|, be it in compressive or tensile stress, since improper consideration might render improper limiting slenderness parameter for compact element measure.

 

[swearingen]

What code and section are you referring to?




If you "heard" it on the internet, it's guilty until proven innocent. - DCS

http://www.eng-tips.com/supportus.cfm

 

[ishvaaag]

It is the table B4.1 in section B.4 of Chapter B as I put in the header, and sorry, I omitted that it was AISC 360-05 code, as currently downloadable from AISC.

Then you go to point 11 in the table.

 

[wannabeSE]

That is a good question. In F4, the limit state of lateral torsional buckling is concerned with the compression flange yielding. But, there is the limit state of tension flange yielding. Both limit states use the compact vs non compact web criteria.

My bet is on the compression flange yielding since the compact criteria is based on h_c/t_w. The commentary states the provisions are based on research repoted by White in 2003. Perhaps you can try to get a copy of the report or contact the author.

 

[ishvaaag]

Thanks wannabeEIT and swearingen. In fact for the moment (I am just for now reading the code, and I don't practice in US) I have not been thinking on the reason of why the limit is stated so or where it comes from, am just attempting just know what the correct interpretation is. So any guide is very welcome since it will ease any further efforts of true understanding. Thankyou very much.