AISC Code Unity Check (Unbraced Length)
AISC Code Unity Check (Unbraced Length)
(OP)
I am performing an AISC unity check per section H-2. I am trying to specify my unbraced length L (KL/r) in order to determine Pc for the axial compression buckling.
I have attached a sketch that shows configuration. I have a 5x5 tubing member that is supported along its entire length in the weak and strong axis via crimped plate and flat plate (note sketch attached). Is my unsupported length L 0?
Thanks in advance.
I have attached a sketch that shows configuration. I have a 5x5 tubing member that is supported along its entire length in the weak and strong axis via crimped plate and flat plate (note sketch attached). Is my unsupported length L 0?
Thanks in advance.






RE: AISC Code Unity Check (Unbraced Length)
But your Lb wouldn't be L either. You could conservatively take it as L.
RE: AISC Code Unity Check (Unbraced Length)
Would this act as an acceptable support to brace the 5x5 member shown?
Thanks.
RE: AISC Code Unity Check (Unbraced Length)
If not, you should check the tube and plates as a composite section.
DaveAtkins
RE: AISC Code Unity Check (Unbraced Length)
Thanks for the help!!!
RE: AISC Code Unity Check (Unbraced Length)
To evaluate the strength and stiffness of the plate for bracing I would probably consider it to be similar to a diagonal brace that kicks out a a 45 degree angle towards the adjacent column. The effective width of the plate would be the difficult thing to establish. I would think it would be something like 25% of the distance between the two columns. But, that's just based on eye-balling it. Not sure if there is a more rational procedure for coming up with this value.
RE: AISC Code Unity Check (Unbraced Length)