Beam transverse stiffeners vs double angle connections below concentrated loads

[mbstruct]

Lately, I've been designing steel connections on a few projects. I've seen several typical details from engineers indicating full depth transverse stiffeners to be provided in the web of beams supporting gravity columns from above, regardless of load magnitude. Transverse stiffeners are typical specified if web local yielding, web local crippling, web side-sway buckling, or web compression buckling are of concern. I was wondering, if a pair of double angle connections occur beneath the concentrated load, is there any research available on whether or not those double angle connections provide any reinforcement for the local failure limit states similar to a transverse stiffener? My thought is that you have a beam and connection available to brace the web in question, similar to what a transverse stiffener would do. Any input would be appreciated!

 

[human909]

Using a web stiffener as a shear tab connection would be my preference.

 

[mbstruct]

That makes sense. The connection(s) would need to be analyzed as an extended configuration unless the EOR indicated the beam was analyzed for the induced moment, correct?

 

[human909]

That is an something I can't answer because I am unaware of the workflow that is normal for you in your jurisdiction. Where I work it is rare that connection design responsibility is separate from member design.

However I don't see a significant connection performance difference between double angle connections and non-extended shear tabs. Though I believe angles behave a little closer to a true pin than shear tabs especially for deep beams, but in most circumstances this difference is negligible. Where I work shear tabs are standard pinned connections, angle connections are rarely used.

 

[dik]

When I use stiffeners, I usually make them 1" short of the beam depth, with the flange weld at the point load. Unless the load is light, I usually add a stiffener; this is not so much a matter of web crippling, but a matter of maintaining the integrity of the section at what may be the maximum moment location. I've often use the shear tab as a web stiffener. Angles or shear tabs (not to the flanges) can act as a web stiffener, but not so good for web crippling.

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

-Dik