hi
good day everyone.
I have a question about NOTIONAL LOAD FACTOR .
Regarding to AISC 360-16 PAGE 16.1-27 as shown below.
(c) In structures to which Section C2.2b is applicable, in lieu of using τb < 1.0 whereαPr /Pns > 0.5, it is permissible to use τb = 1.0 for all noncomposite members if anotional load of 0.001αYi [where Yi is as defined in Section C2.2b(a)] is appliedat all levels, in the direction specified in Section C2.2b(b), in all load combinations.These notional loads shall be added to those, if any, used to account for theeffects of initial imperfections in the position of points of intersection of membersand shall not be subject to the provisions of Section C2.2b(d).
1.
I try to realize the meaning of that. and if tau-b =1 and notion load will be 0.003 ,
is that right ?
2.
and I try to write the syntax in staad as show below.
DEFINE DIRECT ANALYSISFLEX 1 ALLAXIAL ALLFYLD 235000NOTIONAL LOAD FACTOR 0.003
besides these syntax , is that any syntax I need to take care?
thank you.
Regarding 1, in Direct Analysis the Taub values are determined iteratively based on the axial force in the member. When you set the notional load factor to 0.003 these iterations are not carried out and Taub is considered as 1 which is what the code recommends.
Regarding 2, Added the notional load in X direction for your load case 208. Modified file attached Notional_load_0003_syntax_modified.STD
Regarding 3, the direct analysis implementation in STAAD automatically handles that. There is nothing additional that you have to do.