You are not missing anything.
Per AWS D1.1-2010, Clause 2, skewed T-joints with an acute angle of less than 30 degrees are not capable of transmitting a design load. It is not prequalified. Check the figures for 3.11.
Best regards - Al
If I am picturing this correctly, why would you do any prep at all to the plate edge? A plate that is sheared, cut, at a normal 90° to the face of the plate would in this case yield a 70° groove angle with one corner of the edge of the plate touching the web. Thus, if you prep the plate corner you are going to get an even wider groove angle. Unless, you mean cutting it and then fitting with a 'reverse' bevel so that instead of 70° you would get 45°? So you would put a bevel of 25° on the edge of the plate and then fit it to the web so that you had a 45° groove angle?
That's a new one to me but I can see how it would work. But it would not be your TC-U4a-GF prequalified joint.
Now, I have seen backing bars used in this style joint but can be difficult for the average fitter of today to get the location and all dimensions correct.
So, to play devil's advocate, at what point does a fillet weld in a T-joint (definition of 'fillet weld' combined with Clause 2.2.5.2), become just a weld in a skewed T-joint (Clause 2.3.3) that should maybe be termed a Groove weld when the 'groove angle' due to the angle of the plate reaches a certain point (just as when you bevel the fit corners/edge of your T-plate in a T-joint and have a groove weld) and then back to a fillet weld when the plate angle gets down to a dimension that makes it a 'lap joint' with a fillet weld?
If you look at the majority of shop and engineered drawings with skewed plates between 30-60° the engineer uses a bevel weld symbol.
Did I lose you? I'm sure I didn't lose Al, think about it though. Picture the joint configuration all the way through from a proper T-joint to a full lap joint. Look at the 'groove' angles, opening, when in the middle range.
Main point, this is why the code places the responsibility on the engineer to call out what he wants and specifies the use of additional details with all his required dimensions for the joint.
He Is In Control, Have a Great Day, Brent
If I'm understanding correctly, in my experience, these have been shop welded to the supporting beam and field bolted to the supported beam. I can't imagine the need for a full pen weld just because the shear plate is skewed. With regard to the load it's supporting, it's doing pretty much the same thing that a 90 degree fillet welded shear plate is doing. It just happens to be skewed. If the contact edge of the shear plate is beveled to have full contact with the member web, the welds would then be fillets on both sides. If not, it's been my experience that the weld is a PJP on the "open" side, and fillet welded on the opposite side. This is ONLY for skewed shear plates that are at a minimum 30 degree angle. Anytime I have encountered anything less than a 30 degree angle, the EOR has always approved an "open" bent plate, fillet welded on three sides (like a framing angle) to the supporting member. The other thing with skewed shear plates less than 30 degrees is to make sure the holes in the shear plate, (or bent plate) are far enough out so that the beam web doesn't interfere with field bolting. I know that as the lever arm is increased (moving the holes farther away from the beam web) the bolt value can decrease.
Thanks so much for the quick replies and confirming that I am not missing something.
Our next step is to propose an alternate connection to the engineer.
We will inform him that his callout for a CP weld, using the detail he shows on design, cannot be achieved with a pre-qualified procedure.
We do have an alternate solution.
Thanks all,
Alan.
Forum
