HSS wall plastification

[MacGruber22]

Proposition: welding 1/2" dia. threaded studs to exterior side (centered on wide face) of 6"x2"x1/4" rectangular HSS for some connections.

Question: Are the traditional HSS T-section wall plastification equations of section K2 appropriate to use here?

Something tells me that one or both of these checks may be unconservative for such a relatively small diameter branch "member" (1/2" dia stud)
From Eq. K2-3 phiPn = 4.70 kips
From Eq. K2-4 phiPn = 10.3 kips

"It is imperative Cunth doesn't get his hands on those codes."

 

[KootK]

I'm not sure if the AISC equations would be conservative or unconservative but I think that there may be a simpler way to go about this. I believe that AWS limits plate thickness to stud diameter divided by 2.5. I have always assumed that to take care of localized plate plastification and punching shear-esque issues. That's only plate related check for studs on composite beams I think.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[MacGruber22]

After giving it some more thought, I agree that the minimum plate thickness for studs would take care of the punching shear and weld burn-through. But, a one-way plate with an out-of-plane point load couldn't have an indefinite span length (6" in my case). I guess looking in Roark's formulas for plate would be a way to look at it.

"It is imperative Cunth doesn't get his hands on those codes."

 

[KootK]

But, a one-way plate with an out-of-plane point load couldn't have an indefinite span length (6" in my case).

Quite right. For plate bending checks, I would go with yield line analysis or Roark's as you mentioned.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[MacGruber22]

Thanks, KootK

Initially, I figured I could cover the plate flexural yielding by using the "chord plastification" limit state checked by the first equation.

Is there a strict difference between the terms "yielding" and "plastification"? It just seems like yielding for tube connections.

"It is imperative Cunth doesn't get his hands on those codes."

 

[KootK]

Perhaps a subtle difference. One might take yielding to mean first yielding and plastification to mean complete mechanism formation as in the yield line method. But yeah, generally the same thing.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[MacGruber22]

You hit it right on the head - "Plastification. In an HSS connection, limit state based on an out-of-plane flexural yield line mechanism in the chord at a branch member connection."

"It is imperative Cunth doesn't get his hands on those codes."