Bending of plate with addition of stiffener

[BAGW]

Hi,

Attached is the image below showing two scenarios. The first one is applying point load on the flange and the Beff that can be used for capacity calculation.

Mu = P x a
S = beff x t^2 / 6
Mc = phi x fy x S

Second image is the scenario with stiffener added. How do we calculate the capacity for such cases?

Thanks

 

[Tomfh]

I would do yield line assessment for both cases.

A stiffener acts as a support for yield line solution.

 

[r13]

You won't have cantilever flange bending issue any more. The closer to the stiffener, the more two way plate action. I wouldn't bother to check the local stress, but to check the entire cross section.

 

[Agent666]

Check SCI P398 [download from link], it has a method for evaluating the critical yieldline with/without influence of stiffeners that could be used.

 

[KootK]

If I couldn't get the stiffener more or less under/beside the load, I'd be inclined to not bother, at least not analytically. The difficulty with the yield line approach for a situation like this is that it assumes the plastic availability of longitudinal flange stresses that are simultaneously required for general flexure and warping torsion.

 

[BAGW]

@ Agent666 which version are you referring to? I am looking at AISC 360 V15 and I cannot find it on the page you are referring to.

 

[MegaStructures]

Why not put a stiffener on both sides of the load?

“Any idiot can build a bridge that stands, but it takes an engineer to build a bridge that barely stands.”

 

[dik]

Do a search for SCI P398...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Agent666]

There is a link on the page I linked to to this file SCI P398.

While based on Eurocodes, the method can be applied to any other region/code.

 

[WARose]

A yield line method (like the others have suggested) would be good. AISC has a equation [i.e. J10-1 in the 13th ed.] for the allowable force on a flange for a beam. You have to keep in mind that force is for the full flange width....so you have to break out the % of that force meant for flange bending. I'd read the commentary for that part as well.