Plastic buckling in tension-only braces 2

[rossk87]

Hey guys,

I am designing a building that has concentrically placed double-angle braces as its LLRS.

I want to design these as tension only. To do so, I know that I must check to make sure that the members put into compression buckle elastically, not inelastically. I have obtained compressive forces in the members from SAP2000.

My question is this: to perform this check, is it as simple as making sure that the compressive force is greater than the euler buckling formula but less than sigma*A where sigma is the yield stress of the material and A is the area of the member?

Thanks for your help.

 

[Lion06]

I would say that you need to check the capacity of the member, not the actual load. Whether a member is going to buckly elastically has everything to do with the member properties, not the load applied.

Go through a capacity check and see if you fall in the elastic buckling range or inelastic buckling range. I don't have AISC 360-05 in front of me, but I believe if Fe < 0.44Fy, then you're in the elastic buckling range. See Chapter E of AISC 360-05.

 

[rossk87]

Lion06,

Thank you very much for the input! You are indeed correct that the limit on Fe for elastic buckling is 0.44Fy