Stiffener plate CJP weld term. per D1.5

By qcmcwi Date 12-09-2003 06:02

Am I the only one who thinks that the visual acceptance criteria of D1.5 section 9 does not apply to weld terminations. Terminations are adressed in D1.5 section 3.12 and this only calls for "sound" material as opposed to visually acceptable per section 9.
To me, "sound" is simply not cracked or damaged, every other part of the book references figure 3.3 for profile and 9.21 for quality. Neither of these are mentioned in 3.12 Weld Terminations.
We are applying SAW beads to this piece and the ends are a little lumpy, but, they are cascaded to less than 1 in 10 (3.12.3) and are actually fairly decent. CALTRANS QA doesn't see things the same and they insist on sec. 9.21 like the rest of the part.
Weld soundness is not verifiable by checking for roll, undercut, cracks etc.....

By CHGuilford (****)

Date 12-09-2003 18:52

Personally, I loosely apply the fillet weld face requirements from Figure 3.3 to the ends of fillet welds that don't continue to the end of a member (such as stitch welds or stiffener welds that interupt one weld size back from the joint end). I like to see convex ends with no overlap or undercut and evidence of fusion at the root. It isn't practical to stop a fillet with a sharp 90 degrees edge, so some rounding should be expected.

If the weld extends to the end of the joint (such as web to flange fillet welds) I feel the termination should have the full throat and profile right to the end. In those cases, we put run off tabs at the ends and cut them off flush after the weld is completed.

My opinion is that a weld is most likely to start tearing at an end or a corner so those areas should have welds that have uniform profiles and have full throat. Sub arc welds are deep penetrating but they start off cold so that the fillet starts won't have as much throat there as an inch or so in from the end. I'm talking about the actual throat from the bottom of the weld 'nugget' to the face; not the theoretical throat. So the end of the fillet may have the required size but no 'reserve throat' to increase strength. Those locations would need all the help they can get except that normally dont see the stresses that locations further out on a girder would see. Still, 9.21.1.7 requires no underrun of fillet size, on web to flange welds, for 2 x the flange width for a reason. I don't know why but maybe there is more loading there than it would seem?

Just out of curiosity, CALTRANS is still using the 1995/96 version of D1.5? Section 9 is discontinued in the 2002 version; they spread that info throughout the other sections so you have to dig harder for them.

Just my unqualified 2 cents worth,
Chet Guilford

By CHGuilford (****)

Date 12-09-2003 18:56

I'm sorry, i just re-read your post and didn't see that you mentioned fillet welds at all. I just assumed that's what you are talking about. Did you mean groove welds?

By qcmcwi Date 12-10-2003 04:58

Right, these are CJP at both right angles with a relief chamfer to accomadate fit.
very clearly are weld terminations
CALTRANS is still on 95/96
this weldment is a piece of the new construction Oakland Bay Bridge
very cool project

By - Date 12-11-2003 02:54

Sir:
Unfortunately, I do not have the 1996 edition of D1.5. Looking at the 2002 edition, however, I see that paragraph 3.6 does not exclude weld terminations. The term “sound” in paragraph 3.12 has to be interpreted to mean that the weld meets the visual and any applicable NDT acceptance criteria, including profile and reinforcement. For the visual acceptance criteria then, Figure 3.3E applies, and effectively prohibits groove welds that are less than flush with the base material.

Paragraph 6.5.4 states, “the Inspector shall examine the work to make certain that it meets the requirements of Section 3 and 6.26. The size and contour of welds shall be measured using suitable gages.”

Figure 2.4 (Details of Welded Joints for C JP Groove Welds) of the 2002 edition also requires for T- and corner joints made without backing that “Groove welds in corner and T-joints shall be reinforced with fillet welds with a leg size equal to or greater than T/4, but need not exceed 10 mm [3/8 in.]. T shall be defined as the thinner of the attaching elements”. It flies in the face of common sense to think that these reinforcing fillets should be applied to groove welds that are underfilled.

Additionally, if we pretend for a moment that the code does not limit underfill at weld terminations, you have other practical problems – where exactly does the weld termination (i.e. the point at which underfill becomes okay) start? How much underfill is allowed? This of course is not defined in the code.
Clearly, you cannot allow underfill at weld terminations.

Hope this helps,
Mankenberg