Intermittent Welding

Structural Engineering general discussion Welding, Bonding & Fasteners
#1

I posted this on the other site…

I’ve generally used weld spacing of:
-FOR INTERMITTENT WELDS, LENGTH SHALL NOT BE LESS THAN THE GREATER OF 4 TIMES THE WELD SIZE OR 40MM. MAX CLEAR SPACING SHALL NOT EXCEED 12 TIMES THE THINNER OF THE TWO SECTIONS JOINED FOR JOINTS IN COMPRESSION AND 16 TIMES FOR JOINTS IN TENSION.

I recently came across the following:
-FOR INTERMITTENT WELDS, LENGTH SHALL NOT BE LESS THAN THE GREATER OF 4 TIMES THE WELD SIZE OR 40MM. MAX CLEAR SPACING SHALL NOT EXCEED 24 TIMES THE THINNER OF THE TWO SECTIONS JOINED (AWS D1.1 2004 2.11.2-1).

I don’t know where the first spacing came from (I’ve always used it, but don’t know the source), but the AWS stipulation allows a greater spacing. Is anyone familiar with the first criteria? and are there any caveats about using the second criteria as long as the weld is strong enough?

For an intermittent weld, 4@12 means 4" of fillet weld at 12" centre to centre of weld group; is my understanding correct?

Dik

#2

I can often be drawn down into “paralysis by analysis”.
On a subject like this, you can look at the vulnerability of the joint to buckling and its exposure to compression and shear. Even if the cross-sectional area of the connection is OK to pass the loads, sometimes the unsupported parts of the joint have a “long column” ratio. Then you might add some weld beads just to keep those worries at bay.

1 Like
#3

“What, me worry?” with apologies to Alfred E. Newman…

I was checking some work and the fillet welds were spaced at 18" centres… I typically use 12" max and was wondering if what the engineer proposed was correct. I’ve now updated my Project Notes to reflect the new info on intermittent welding… My project notes are over 450K as a text file, and I edit them as required for projects.

I sorted out the issue, thanks for the comment.

Dik