Capacity of Welded Aluminum Sections

[DHKpeWI]

I have a question regarding the capacity of an aluminum section where intermittent welds are used to connect a “C” shape to a flat plate at approximately 12” O.C.

The Aluminum Design Manual provides specific direction to design members with all or part of the cross section weld affected in 7.2. My understanding is that Section 7.2.2 is to be used for sections with longitudinal welds: continuous welds parallel to the long axis of the member. Does anyone have thoughts on sections with intermittent welds? It seems very conservative to use section 7.2.2 for this situation.
Thanks

 

[ishvaaag]

You are likely right in that the heat affected zone will likely fail to affect part of every 12 in length portions. However the question will stay in the intent of the code through its wording.

 

[Ron]

The intent of that provision is to accommodate the change in metallurgy of the aluminum in the heat affected zone. By code, the property affected zone is one-inch from the weld, all directions. Unfortunately, that's the way it is.

Does the affect occur completely and repeatedly in these areas. No; however, it only needs to occur once...in YOUR weld...to create a problem for you.

 

[DHKpeWI]

Ishvaaag & Ron:

Thanks for the help!