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Cope flange of W14x103 brace?

Cope flange of W14x103 brace?

Cope flange of W14x103 brace?

(OP)
Are there any set AISC guidelines or rules of thumbs that dictate how much of a beam flange can be removed before a cover plate is needed and what impact the cope will have on axial capacity?

I have a W14x103 brace (have of a V-brace) that will have a slight interference with a large value. One half of the lower flange may need 2-3in removed (the beam flange is ~14in wide). Because the member is a brace it is not subjected to moment. I planned to add a cover plate centered on the beam web with an area greater than the loss in cross sectional area at the flange. Can the impact to axial load capacity be calculated?

RE: Cope flange of W14x103 brace?

A sketch would go a mile in really ensuring we all know your situation.

RE: Cope flange of W14x103 brace?

Preamble:

1) if this is a special seismic brace and the cope is near a connection meant to yield in out of plane bending, all bets are off.

2) 2-3" on a 14" flange doesn't bother me much. Unless the column is close to it's squash load, I'd probably just ask for the cope to be gently radiussed and leave it at that.

I don't know of any hard and fast requirements. Accurate capacity evaluation is tough. Here's what I'd do:

1) Make sure that you've got enough section left that it won't yield under load. This usually isn't a problem.

2) Figure out where the centre of compressive stress will be where the axial load must pass through the reduced section.

3) Find the eccentricity between the centre of compression at the reduced section and elsewhere.

4) Design the column as a beam column with a kink in it equal to the eccentricity calculated above.

It's interesting to note that, even with cover plating, there may still be eccentricity issues to contend with.


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.

RE: Cope flange of W14x103 brace?

(OP)
KootK: thank you for this great feedback, this what I'll do. I don't know the load on the brace so I'll assume it's 50% of it's axial capacity.

RE: Cope flange of W14x103 brace?

(OP)
Is it possible to push the center of gravity of the coped section back to the nearly the center of the beam by welding on an angle instead of a cover plate?

From this:
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To This:

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RE: Cope flange of W14x103 brace?

(OP)
From this:
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To This:

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RE: Cope flange of W14x103 brace?

My second thought would be to use an angle to add material and shift neutral axis back to center.

My first thought would be to ask the ask the mechanical to lower their valve a couple inches!

RE: Cope flange of W14x103 brace?

Quote (OP)

Is it possible to push the center of gravity of the coped section back to the nearly the center of the beam by welding on an angle instead of a cover plate?

It's not clear to me how you'd manage that but, if you can, I certainly agree with the approach. And you're quite welcome.

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.

RE: Cope flange of W14x103 brace?

if the valve cannot be moved....check a different size memb or a pipe, HSS or fabricated memb...

RE: Cope flange of W14x103 brace?

Assuming that you can't change the size, how about notching the other side (to keep it symmetrical) and cover plating it?

RE: Cope flange of W14x103 brace?

cliff...at first glance that seems like a good idea but something bothers me about it....one would have to end up with the same or greater weak axis radius of gyration, if not, it may result in a global instability of the brace ......not quite sure ,though, about that...

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