Pipe sleeve moment connection

[sedesigner06]

I am designing a pipe column with a moment connection at the base. For the ease of construction i am looking a having a size larger pipe shop welded to the beam the column is landing on, that way in the field they can just lower the column into the sleeve, single pass weld around and go on.

The question I have is what is the best way to determine the pipe length mainly and wall thickness. My initial thought was to make the sleeve length twice the diameter and same wall thickness as column but was trying to find a way to put some numbers to it.

Thank you for any help

 

[paddingtongreen]

Have you sized the pipe yet? Depending on the size range you are working in, you may not find pipes with the correct difference in diameter.

It might be better to use a backing ring tacked to the beam, prepare the end of the pipe and make a full penetration weld. You only weld once and have the benefit of having the backup ring in place. The backing rings are sized for the inside of the pipe.

Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin

 

[sedesigner06]

I was concerned leaving a backing bar in with a full pen weld due to stress concentration in the backing bar and breaking off. Is there a reasonable concern?

 

[paddingtongreen]

No. The pipe is welded to the beam, there is no transfer of force from the pipe to the backing ring.

Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin