Column Stiffeners

[MacGruber22]

Have some moment frames where the beams frame into the columns at a 7.5/12 angle. On typical jobs, I provide the column stiffener/doubler requirements to the connection designers. I am wondering if it is reasonable to use the horizontal component of the bottom flange force to check the stiffener requirements.

Column web buckling is the limit state that I am particularly concerned doesn't work with the above logic.

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

 

[KootK]

I am wondering if it is reasonable to use the horizontal component of the bottom flange force to check the stiffener requirements.

I would say so. It's hard to imagine that the vertical component wouldn't head off vertically down the axially stiff interior column flange. I would also deem a horizontal stiffener to be more fab-friendly than a sloped one. KootK approved.

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. Easy peasy

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

 

[MacGruber22]

KootK - out of curiosity, do you provide the same to the fabricator? I am in the process of trying to help our office provide more efficient and fabricator/contractor friendly construction documents. We are in the mid-Atlantic where it seems connection design is usually farmed out.

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

 

[KootK]

I don't actually have a typical detail for the sloped condition. Prior to this conversation, I probably would have just shown the stiffener sloped "because it looks right".

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]

I meant in general regarding column stiffeners. Our firm does not do it, but I believe that we should.

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

 

[KootK]

Ah... got it. We do specify the stiffeners in our typical details. That is mostly a matter of laziness and conservatism though. And the fact that I'm generally skeptical of the owner seeing the cost savings unless the project is running under a design assist setup. If the fabricator has tight connection forces to work with, I see no reason why the couldn't be given the option to use stiffeners or nothing/alternate means. I like the improved joint stability that you get with stiffeners but that's a "nice" thing not a "necessary" thing in most cases.

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.