double back to back channel in STAAD 1

[gorgik]

Hi,

I'm modeling aluminum truss member-diagonal in STAAD. I'm using double back to back channel with bolt in the middle of the length.
First, i'm not sure whether k is 0.5 and in which direction(strong or weak) i have to apply it . Second, in the design input for aluminum design i'm getting very close allowable stress no matter i modified KY=1(allowable stress=4.77ksi) or KY=0.5(allowable stress=4.99ksi), Y is weak axis.
Any advise?

 

[SethGuthrie]

For others who come across this post there is a duplicate with answers here:

http://communities.bentley.com/products/structural/structural_analysis___design/f/5932/t/93536.aspx