Welded Plate at an angle

[Ussuri]

I have the situation where I have a plate fillet welded to a beam at 50 degrees from the horizontal. Because of this angle the weld throat thickness is reduced on one side of the plate and increased on the other.

I discussed with a colleague who advised that the welding codes (both British Standard and AWS) do not allow you to take a throat thickness larger than 0.707 x Leg Length for an acute angle in design, and conversely specify that a weld over an obtuse angle must be built up to ensure a minimum throat thickness of 0.707 x Leg.

I have been unable to find a reference to this in any of BS's I looked at, and do not have access to AWS D1.1.

Could someone advise if this is the case, and where I could find the supporting information?

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[Goahead]

May I suggest to look at the problem from a slightly different point of view?
If you are not bound by a specific code, it is reasonable to check your design for the loads it has to support. In your presentation the fillet welds seem to be designed without any penetration at all. But by chamfering the plate you may achieve full penetration, if necessary.
Examples of Joint designs for Complete Joint Penetration are illustrated in fig. 5.42 of AWS Welding Handbook 9th ed. Vol. 1 at page 221, with one element at an angle and full penetration.

http://www.welding-advisers.com/

 

[gtaw]

AWS D1.1 Structural Welding Code/ Steel would consider that to be a skewed T-joint. You would have to take into consideration that there will be a void at the root. This is called the "Z Loss Dimension". In other words, don't include the first 1/8 inch of the throat dimension as being capable of transmitting any load.

For the acute side having a dihedral angle less than 60 degrees, but more than 45 degrees, you can assume the Z loss to be about 1/8 inch. Then size the weld based on the throat dimension (shortest distance from the actual weld root to the face).

Hope this helps.

 

[valleyboy]

You could also consider improving the connection with a triangular stiffener placed between the flange of the beam and your plate fitting to the connected member. The additional length of welding will provide additional capacity.

VB

 

[Ussuri]

I think ultimately the joint connection will be changed to a full pen weld just because of the size of plate to be fixed.

gtaw, so AWS does cover the acute angle. Make perfect sense not to include for all the increased throat. Does it say anything about acheinging a minimum throat thickness when dealing with the obtuse angle?