Strength of Spot weld with Welding Washer

[RFreund]

Does a welding washer increase the strength of a weld or does it just allow the weld to achieve its calculated capacity.

I'm looking at allowable diaphragm shear values for a 24ga metal deck and they seem much higher than the spot weld would allow for. However the Diaphragm manual says to use washers over 22 gauge so I'm wondering if that increases the strength. If so, how is this calulcated?

Thanks!

EIT

http://www.HowToEngineer.com

 

[KootK]

Check out the attached doc and then perhaps follow up with a call to SDI if necessary. No time to read it through myself this morning I'm afraid.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.