Tolerance for sagging at Beam to Beam Weld joint

[hetpatel1104]

Dear Experts,
During fabrication of Tank Roof structure, we are facing some distortion / sagging at Beam to Beam butt welded joints (A992 W shapes).
Can you guide me how much is the tolerance for it and which reference documents to be referred (AISC or other)?

 

[Mjkkb2]

I have a hard time visualizing your problem. Not sure what sagging 'at weld' really means. Are the beams themselves deflecting or is the problem only with a connection? If the latter then do you mean there is a rotation at the connection? IF butt welded then it is not possible, please provide more info...

 

[hetpatel1104]

Mr. Mjkkb2,

Sorry for making you inconvenient.
It's rafter member butt joint and distortion is happened at butt welded joints.
Kindly refer the attachment which may give you better idea.

Appreciate your guidance,

Regards,
Patel

 

[jayrod12]

Could it be that the welding was just a little suspect? If the weld is low maybe they ground off a bit too much when they were cleaning it up.

 

[JAE]

Could be many issues - welding done too hot seems like the main possibility.

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[Mjkkb2]

If the rafter is deflecting/sagging then maybe the rafter is undersized for its span. If the weld was done poorly (not full penetration provided) then it either have to be tested (UT), reopaired or deemed insufficient and replaced. Is the member isntalled yet and loadedd with roofing/ etc.. or not?
IF there's any overgrinding visible then the capacity of the member/section is reduced and it needs to be repaired.

 

[Mjkkb2]

good pint JAE - improper welding technique could be to blame also...

 

[hetpatel1104]

Thank you All !!