placement of steel stiffener

[jp1990]

Not my field, but I gotta ask?
I do also like to know why.
I hope for some insight.
tnx.
regards.

 

[JLNJ]

Presuming that the stiffener is there to help distribute the beam bearing forces, you place the stiffener centered on where you want the bearing force to be transferred.

Usually this would be on the center of the wall, or maybe the center of a bearing plate which may or may not be centered in the wall.

It's all about the load path you choose.

 

[Eagleee]

The stiffener also prevents cross section distorsion there.

 

[KootK]

1) I think that you could make a rational argument for both arrangements here. At a masonry support, loads will not be particularly high and the main purpose of the stiffeners is to keep the beam from rolling/swaying over. Both arrangements will address that.

2) The rotation of the beam will tend to shift the reaction point towards the face of the masonry which kind of implies that would be a good place for the stiffener. Presumably that's what's prompted you to ask the the question. In response to this, I say... yeah, tough to argue with that.

3) Like JLNJ, I'll put the stiffener over the center of the wall in the hope that will encourage the load to be delivered over the center of the wall. There's some merit to that logic but, in other respects, it's probably wishful thinking. Technically, it would be nice to have a soft bearing pad or a rocker in installed at the bearing as one might with a large precast beam connection. That seems to be overkill in more conventional applications however. I feel that having a rather stiff beam in these situations is a good thing to keep end rotation down.

4) A related concern arises when the beam is bolted/welded to the connection plate as is usually the case. You can end up developing a couple between the reaction at the face of the support and the incidental tie down at the connection. In at least one unfortunately slender beam, I've seen this pry the weld plate out from the masonry.

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.