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What type of weld on this simple shear connection? 1

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StrucDesignPE

Structural
Dec 19, 2014
110
What type of weld would you specify at this location? Flare Bevel? Fillet? Fill in the gap at the beginning of the HSS radius and then weld? WT is not movable. This is simple shear connection of WF beam to HSS column with e=3". Small 10k load. Figure 8-13 in the AISC manual requires a minimum shelf distance for a fillet weld which is not provided at either side of the WT flange so I don't think I should use a fillet weld, but there really is no radius for a flare bevel to fill. The size of the WT flange in relation to the column width cannot be changed to be larger than or smaller than the column.

wt_hss_weld_t6a3zk.jpg
 
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To clarify on your last comment that the T can't be changed, why not? They couldn't cut off 3/4" so it's just a standard fillet?
 
Provided you can't make the minimum PJP from AISC Table J2.3, I would apply a fillet weld and go forward with a reduced weld effective throat. If that's not an option or if the job QC determines the fillet is outside the AWS prequalification specs, you could trim the lower leg of the WT, as req'd, to make room for your fillet.

Jayrod beat me to it.
 


The angle is about 135 degr and i would specify PARTIAL PENETRATION GROOVE WELD with build out to full thickness required.
 
I guess my thought was that trying to cut the T-flange back even 3/4" would still not get me to AISC's recommended minimum shelf per Figure 8-13. Thoughts?
 
Cut the flange back to whatever dimension is required to make a fillet weld work.

Use a PJP weld (bevel the back side of the flange).

Either option would work. From a fabrication perspective it is about the same amount of work - machine/cut a bevel vs just cutting the WT flange.
 
Rather than cut the flanges back to give yourself room for a proper fillet weld, you could use a wider WT to get a proper flare bevel. You're just talking connection material here so I'd rather go with a slightly heavier WT to get the width and save on trimming the flanges - we're talking minimal extra material but saving a decent amount of labor.
 
Canpro... that's likely what I'd do...

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

-Dik
 
Is there a reason you can't just use a traditional shear tab and forego the WT all together?
 
I guess my thought was that trying to cut the T-flange back even 3/4" would still not get me to AISC's recommended minimum shelf per Figure 8-13. Thoughts?

I'm not sure that figure applies in this case. You have a curved shelf. I'm no weld expert though. It is certainly an interesting point.
 
Foregoing the WT for a single plate connection would be my preference, but this is a delegated design where EOR has requested WT connection. I looked back through the different WT sections and think I found a slightly larger one that will have minimal impact on my other connection calcs and only require a slight trim of the flange. It will give me a clearly defined flare bevel weld at the HSS radius.
 
JoshPlumSE said:
I'm not sure that figure applies in this case. You have a curved shelf. I'm no weld expert though. It is certainly an interesting point.

I thought the same because it is discussing the double angle connections on a beam flange or web, but I couldn't find anything else in the manual or even just searching online for connection design examples. AISC gives good examples of tees wider than or more narrow than the HSS column, but don't talk about this scenario. I guess it is easy enough to size up the tee if needed to avoid my complication.
 
It sounds like you got this figured out, but thought I would offer further discussion on the fillet option (and why its not ideal).

It is certainly weldable as a fillet, it just becomes more complicated as the throat size is no longer as strait forward (It is not 0.707 X leg length). As far as prequalified welds are concerned, you couldn't count on any penetration depth for a flare-bevel (for a flush filled weld you only get 5/8r for the penetration depth). So, you would need to treat it more as a skewed fillet, and draw out the geometry to determine what throat depth you could actually get - this may or may not be large enough for your loads. See below sketch for what I am getting at:

weld_throat_mte2um.jpg


As you can see above, the weld throat is L*sin(Θ) where Θ is closer to 27° rather than 45° (so closer to 0.45L rather than 0.707L).

This would also result in the weld throat size being easily affected by fitment and steel shape size tolerances. The flange width may be wider than planned due to mill tolerances resulting in a smaller weld.


The following sketch shows that a PJP weld would still be straight forward for this geometry:
weld_t_pjp_izrrsf.jpg
 
I like CANPRO's suggestion of using a wider WT to get a standard flare bevel. My next preference would be to bevel the flange of the WT as shown in dauwerda's second drawing, along with maybe trimming the WT flange to get completely away from the HSS radius. You could also pitch this back to the EOR and ask to substitute a single plate.
 
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