Stiffened Seat

[slickdeals]

Folks,
I have a rather stupid question to ask. I am trying to design a stiffened seat/bracket to support reactions from a beam.

The bracket will support a beam that forms part of an expansion joint. I am trying to use 3 vertical stiffeners in lieu of 1.

The reason is that I don't want to rely on bracked flange bending to resist the reaction. How can I design the bracket such that each stiffener gets its fair share (middle getting 1/2, other two getting 1/4).

How can I be sure that all my load is not going into the middle stiffener (one that is parallel with the beam web).

Thanks

 

[youngstructural]

Okay, so you really, REALLY need to check these numbers, because:

1. I haven't worked in Imperial units in three years.
2. I have never used Yield Line Analysis on a stiffener before.
3. I have done this quite quickly, much more as a proof of concept for you to see and get a feel of Yield Line work.
4. These numbers have NOT be checked.
5. I have been conservative in considering a reduced plate area (to simplify the analysis) and used the full 200k on only one plate, HOWEVER, I have simply assumed that the plate needs to have an internal elastic bending strength capacity equal to the 2.5% stability strength brace force. Euler critical buckling strength may be more appropriate; You'll need to satisfy yourself.

That said, it appears that your steel plate should be fine for ULS loading. Please see the following document, available as a free download, for further information:

Practical Yield Line Design by G. Kennedy & C.H. Goodchild
from The Concrete Centre (UK)

http://www.concretecentre.com/main.asp?page=195

Sorry about all the caveats, but I haven't had the time to really think the problem through any further; I'm under the gun on a stadium job this week!

Hope it helps and doesn't hinder,
Cheers,

YS

B.Eng (Carleton)
Working in New Zealand, thinking of my snow covered home...

 

[youngstructural]

*bump*

So what did you do in the end Slickdeals?

Just curious...

Cheers,

YS

B.Eng (Carleton)
Working in New Zealand, thinking of my snow covered home...

 

[slickdeals]

YoungStr,
Your calcs were useful to help understand a different way to check buckling. I found that the AISC code has design requirements for a triangular bracket plate (which is different from a stiffener plate with the free edge parallel to the line of loading). The triangular bracket plate has a b/t ratio of 250/sqrt(fy), considerably different than the one for a plate stiffener 0.56 * sqrt (E/fy).

Regardless, thanks for your help.

~Slickdeals