design for welding

[HgTX]

Goahead posted this link in another thread:

http://www.thefabricator.com/Articles/Welding_Exclusive.cfm?id=1062

I liked the article--good for "knowing what it is you don't know". I'm in fabrication, not design, and I don't know nearly as much as I should about welding. The designers I encounter know even less. Astoundingly few bridge designers, for instance, know what's in the AWS Bridge Welding Code, and so designs are produced that violate code provisions. Never mind whether their designs are the most efficient--they don't even meet code.

But I'm not sure how much of the list in the article really needs to be understood by a designer. Some of it should be left up to the fabricator and detailer--so I guess what the designer needs to know is what really needs to be shown, and what should they leave to someone else's wisdom.

The article author says a designer should be an "expert" in the following:

Base and filler material properties and selection
Metallurgy and weldability
Restraint's influence on stress concentration
Design of joint details for fatigue resistance
Design for corrosion resistance
Design for durability in operating conditions
Design for manufacturability
Process expertise and influence on properties
Need for additional thermal treatments
Finish treatment selection
Weld sequences and distortion control
Weld joint dimensioning
Formulation of appropriate quality requirements
Design for safety
Design for inspectability
Design for maintainability
Integration of design and procedures to ensure minimum cost
Use of weld and inspection symbols and pertinent notes
Use of appropriate code requirements

But the author doesn't make a distinction between, say, a designer of a major public structure whose fabrication and detailing will be handled by another party more familiar with the ins and outs of welding, and someone actually working for that fabricator or detailer who needs to decide the final details of the welding and welding process.

For the first case, I don't think that whole list applies--at least not to the "expert" level. Thoughts?

Hg

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[metengr]

I would agree. This is a "wish" list of items that should be considered, and the point being that no "expert" will even come close to having all of these core competencies.

The article brings out the fact that engineers in design, fabrication and field installation of projects need to know their limitations, and bring in or draw on the necessary expertise from the concept phase to completion.

The only negative related to this article is that it is obviously self serving considering the author is listed as a "welding consultant".

 

[ryderbull]

I would agree as well. In general, in the oil and gas facility industry, very little thought goes into welding design and the welding theory behind welding. We tend to weld all points of contact and all of our weld sizing is based on the size of the materials being connected. Very little, if any, actual design of welding actually occurs. I don't know anybody in this business who actually designs weld. It is always eye-balled. I guess it's pretty scary.

 

[MadMango]

Over half of the listed topics can/should be considered in every aspect of the design process, not just welding.

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