Built Up Steel Box

[kylesito]

I am having some trouble coming up with a way to analyze a built up steel box.

The box is 5'-0"x5'-0" x 2'-0" tall. It is comprised of 3/8" thick plate with 1/2" thick floor plate and has 1/2" angles at each corner.

My objective is to determine how many of these boxes can be stacked on top of one another...ie, compression strength of the side plates.

I have tried looking at it through AISC Section E7 but I believe my math is getting screwed around. Also, I am not sure whether the provisions of torsional and flexural torsional buckling apply in this situation or just flexural buckling.

Anyone have experience analyzing built up members using this specification?






PE, SE
Eastern United States

"If a builder builds a house for someone, and does not construct it properly, and the house which he built falls in and kills its owner, then that builder shall be put to death!"
~Code of Hammurabi

 

[bridgebuster]

Are you just stacking the boxes and not making a rigid connection between adjacent boxes? If that's the case then you just need to determine the capacity of the bottom box as a built-up compression member. You could treat the corner angles as the primary components and consider the plates as battens (might be too conservative; or just take it as a rectangular column. You could determine the capacity of one plate assuming it's supported on two edges. Roarke should have a formula.

Based on your description I don't see flexural buckling as coming into play.

 

[a7x1984]

Sounds like local crippling of the plates may be your limit state of failure. What in God's name is this for. If I didn't see your P.E. and S.E. I would have thought you were a sneaky student trying to solve homework problems!

If I got paid for every hour I worked, I'd be a wealthy man.

 

[jbeckhou]

DNV 2.7-1 may provide some help.

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