Fillet welding on a radius

[port125]

We have a 3/8" thick plate to weld to a supporting member. To do this we are thinking of cutting a hole and using a fillet weld inside of the radius of the hole.
Using a 3/16" weld, what is the tightest radius that can be used.

Our senior engineer says this process is frequently used, however we can't find a manual that gives a minimum.

 

[connectegr]

This is a "plug weld". Look for information on plug welding in AWS D1.1

http://www.FerrellEngineering.com

 

[port125]

We would like to avoid a plug weld, from what we understand with a plug weld you are required to fill the hole with weld material.

Plug welds have spacing requirements that would be prohibitive in our situation. form the AISC 13th pp. 16.1-98 the minimum center to center spacing shall be 4x diameter for a plug weld. It seems this would not apply to a fillet weld around the inside of a hole. if you used a 2" dia. hole with fillet welds do you really need 8" c/c spacing?

at what point does it stop being a large diameter hole with fillet welds and start being a plug weld?

rather than relying on the faying surface to transfer shear we would be relying on the effective throat area like normal fillet welds.

 

[azcats]

The minimum means you can't go closer. I think you're confusing a min spacing with a max spacing. I didn't see any limitations on maximum spacings...granted I didn't look that hard.

 

[port125]

I knew I saw an example for this somewhere. ..
The AISC Detailing for steel construction 3rd addition addersses this.

In the 3rd addition the table for the minimum radius is bogus
So I checked the 2nd edition, the tabele is non-existant.
So I checked the "engineering for steel construction" red book
for a 3/8" plate the minimum hole diameter or slot width is 15/16" to utilize fillet welds instead of plug welds.