steel cantilever stiffeners 1

[greznik91]

Hello, Im designing a steel cantilever above entrance. I have to adimt I havent done things like that for a long time now.

I'd like to ask you guys, what's the difference between option A, B and C?

as far as I understand, stiffener enables to achieve a proper moment transfer from a steel cantilever - spacing between bolts/anchors.

With choosing option A, I'll most likely get smaller steel beam section but thats about it.
With option B and C i think I get a compression force from where stiffener ends that acts on web of a beam web. Correct? So I may need vertical stiffener there between flanges right?

Forces on bolts will be the same no matter which stiffener I chose.

Am I missing something?

 

[klaus.]

Yes...basically all are similar regarding support forces




best regards
Klaus

 

[dik]

Can you not use a deeper section? Likely less costly and with LTS it is likely a lot simpler. Maybe even an HSS?

Dik

 

[BAretired]

The vertical stiffener is subject to buckling. It may need to be stiffened in options A, B or C.

BA

 

[dhengr]

Greznik91:
In fact, if you took a deeper WF beam and split it diagonally, along the length of its web, and then welded on a slightly larger bottom flange, you could kill several birds with one stone. In this way, you can more nearly fashion the depth of the beam to fit the load conditions along its full length. The huskier bottom flange is needed because it is in compression and because of potential for buckling. This split member makes two of the final cantilever beams.


It always amazes the hell out of me that OP’ers are too lazy to put some dimensions and approx. sizes on their drawings, assuming they bother to provide drawings, which you have, to your credit. Then, what about a few other, all critical, design considerations like load conditions, make-up of supporting structure, etc. These are really important if you want some meaningful discussion and advice. After all, a 2' long by 3' deep corbel is a cantilever, and so is a 200' high antenna tower, but you don’t design or think of them the same way. They are both cantilevers, but they are two completely different problems. And, your problem will have different design considerations too, depending upon the canti. length being 6 or 8' or being 20'. A couple anchor bolts are usually not enough attachment for an entry canopy/canti. And, you don’t usually like the stiffeners hanging down below the canopy at an bldg. entrance, they tend to be human head splitters. Why not use a tension tie-rod back to the bldg. and above the canopy?

 

[dik]

Is there any need for this complexity?

Dik