Maximum fillet weld on 8x8x3/16 HSS

[Greg Peterson]

I have been asked to look at a fix at a retail location involving corroded bottoms of tube columns. The tube is 8x8x3/16. The Contractor has welded a 3/8" plate all around it then at the top of the plates a 3/8" fillet weld to connect the plates to the TS. My concern with the 3/8" fillet weld is that it is too large for a 3/16" wall thickness. Too large meaning the weld went all the way through the TS wall and possibly created more problems than it solved.

The fix had already been implemented and I only had been asked as the Municipality wanted the approval of a structural engineer.

Any thoughts?

 

[driftLimiter]

What is the orientation of the members in this connection. The maximum fillet thickness being equal to the maximum wall thickness is a commonly misunderstood provision that may not apply.

 

[Greg Peterson]

The plates run vertically on the outside of the TS from base upwards 30" or so. It is where the tops of these 4 plates are welded to the tube column that I am wondering about.

 

[driftLimiter]

The weld is limited by the thickness of the plate on the outside, i.e. 3/8". you can build up fillet weld on a 3/16" surface without penetrating it.

 

[sbisteel]

Sounds like a lap joint, limited by the 3/8" thick plate. AISC limits the leg size to 1/16" less than the thickness of the lapped plate, i.e. 5/16".

 

[Greg Peterson]

Thank you everyone.

 

[DrZoidberWoop]

For reference, the fillet weld to develop the HSS wall is (ASD): 0.5*0.6*Fu_HSS*HSS_thickness/(0.928)

I'm not sure what the Fu of existing HSS was, but 3/8" fillets are wayyyyy overkill.

 

[dik]

CIDECT has test info that a weld size approximately 10% to 15% greater than the wall thickness is almost equivalent to a CJP weld... I don't know how that plays out compared to the Dr's equation.

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So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik