Thickness less than AWS D1.1 minimum 1

[Yt.]

Hi
I want to make some fillets weld (T and corner) with carbon steel thin plates (2 and 3mm).
Checking the AWS D1.1 (2015) i found the minimum specified thick is 3mm (1/8") which is ok with some of my work. (Figure 3.5 page 105)
The issue is that i don't need a 3mm plate for the low stressed plate (2mm) which is relative large and that will imply an unnecessary cost.

What would happen if I weld the 2mm thick plate with 2mm sized fillet weld any way?
This plate will be transferring shear to a tubular section and some moment.

I was thinking an intermittent minimum length/size fillet weld for the long side of stiffeners (But by taking the minimum length as 4 times the weld size and not 38mm -2.4.2.4) and a longer fillet weld at the tubular section (shear transfer and stiffeners)

How much distance could I have between these "pointed" welding?
What problem could i face (structurally)?

I attached one sketch of the member. The stiffeners aren't draw and the tubular connection have been changed to local reliability. It will be attached to a wall.

 

[SectionIX]

See Clause 5.13 then examine Note b of Table 5.7 on page 181 for your weld size question. The rest of your questions should fall into place...

 

[Yt.]

Thanks a lot !!

 

[Yt.]

But wouldn't there an issue by welding a thin plate by both side? I'm thinking about the HAZ

 

[SectionIX]

Possibly, depends on your welding parameters, but you, (I'm assuming you are the Welding Engineer) are in the best position to evaluate that concern. If it was me, I would have a couple mock-ups made and perform Visual and MPI (black/white or fluorescent) on the finished welds. Further, preparing metallurgical mounts from sectioned welds will show you exactly how your materials will react during production welding.

 

[DekDee]

Why are you not using AWS D1.3 ?

 

[Ron]

Agree with DekDee

 

[Yt.]

Thanks for the advices. Finally, i search about theory of plates and realized I needed another approach to get my goal.

 

[gtaw]

The Engineer (the Owner's representative) has the authority under the auspices of D1.1 to depart from the requirements of D1.1. The Engineer and add to, delete, or modify the requirements of D1.1 if there is a need to do so.

Best regards - Al