Groove welds in Lap Joints
Groove welds in Lap Joints
(OP)
I realize that fillet welds are most common in lap joints. However, due to certain restrictions I need to use a groove weld in a lap joint to acquire the desired strength. My question is if this is acceptable or if I need to alter my design in another way to accomodate the decreased weld strength. (Just for a little background, the weld is to be used in cross bracing for a curved girder bridge and the existing design is coming up short in fatigue. I am using MDX to analyze the structure and seem to be getting the same results as it is unfortunately. Any info would be greatly appreciated.)






RE: Groove welds in Lap Joints
Other groove welds which can be used in lap joints with plate include inter-alia: J-groove and square groove
This sort of joint will not be considered prequalified per AWS D1.1 and qualification testing will be required. I guess you are using D1.5 and I suspect it too may also require qualification testing.
RE: Groove welds in Lap Joints
Keep in mind that a groove weld in that context will be a partial joint penetration weld, which is probably a big no-no for your application unless you can weld down the sides as well (as I assume you would have with the fillet welds) to keep the space along the lap from opening under reversal of stress.
Have you tried enlarging your gussets so you can use longer fillet welds?
Hg
Eng-Tips policies: FAQ731-376
RE: Groove welds in Lap Joints
RE: Groove welds in Lap Joints
shape and edge finish.
Hg
Eng-Tips policies: FAQ731-376
RE: Groove welds in Lap Joints
Is the requirement in D1.5 prohibiting the use of groove welds as a solution similar to Section 2.17.1 in D1.1?
RE: Groove welds in Lap Joints
The difference between a PJP groove weld and a fillet weld can get a little subtle--and a little irrelevant, if I may say so.
However, a strict reading of the bridge code puts more restrictions on the PJP groove weld than on the fillet weld. 2.6 says "PJP groove welds shall not be used where the applied tensile stress is normal to the effective throat of the weld."
Section 2.10 has a lot to say about lap joints in general. They keep talking about fillets and never about PJP but the only difference between one and the other is the bevel prep. In a way, a PJP groove weld can be considered a fillet in a groove. Others will now jump all over me about how they're TOTALLY DIFFERENT AND HOW DARE YOU SAY OTHERWISE.
If it were my call, though, I wouldn't have a problem with beveling back the lapping member to get more weld in there, thus technically making it a groove rather than a fillet weld.
Okay, off to ask AWS about why PJPs would be barred where fillets are allowed...
Hg
Eng-Tips policies: FAQ731-376
RE: Groove welds in Lap Joints
RE: Groove welds in Lap Joints
RE: Groove welds in Lap Joints
Hg
Eng-Tips policies: FAQ731-376
RE: Groove welds in Lap Joints
Thanks again for all of your help.