Flexural buckling failure mode 2

[tsg25]

Hello,

Ø5" x ? wall x 24" long HSS subjected to a 10 ton axial load.

Per the specification, the equation for inelastic buckling would apply (E3-2), but I wonder if flexural buckling would really be the governing failure mode? At some point, isn't the limiting factor just the compressive strength of the material?

Thank you.

 

[JoshPlumSE]

You're looking at the chapter for compression members in AISC. Therefore, there are three modes of failure to worry about:

a) Yielding of the material. This would control for members that have a relatively short unbraced length and which have a relatively large wall thickness. If you look at equation E3-2 you'll see that when Fe gets very large, it converges on Fcr = Fy.

b) Flexural Buckling of the member (whether it be elastic or inelastic). For Elastic Buckling this would be equation E3-3, for Inelastic Buckling this would be Equation E3-2.

c) Local Buckling based on the d/t ratio of the cross section. Essentially, the cross section is so thin that it would buckle before yielding or regular buckling occurs. This would be section E7.2.

 

[tsg25]

Thank you, Josh.

I was pretty sure that's what the convergence indicated, thank you for clarifying. I will check for local buckling as well.