Number of Load Tests Required for Structural Significance
Number of Load Tests Required for Structural Significance
(OP)
I'm helping a client come up with bending capacities for a new curtain wall system split vertical mullion. It's sketchy stuff so I'm recommending some testing. I'll have to come up with a testing program though and that's currently where I'm stuck. I would have thought that there would be a standard out there for testing structural things. You know, this many tests if you want to be at this confidence level. Does anybody know of such a standard? Or is time to bust out stats for engineers and go first principles on it? The blurb below comes from Canada's aluminum standard.
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.






RE: Number of Load Tests Required for Structural Significance
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RE: Number of Load Tests Required for Structural Significance
- ASTM E529 - Standard Guide for Conducting Flexural Tests on Beam and Girders for Building Construction. All they say is at least two tests and it depends how much confidence you want to have.
- ASTM E330 - Standard Test Method for Structural Performance of Exterior Window... I believe that this is the most common testing but I'm unclear if it's appropriate for product development or is meant only for project specific verification. This test would have the the mullions LTB braced by the glass. I'm not sure that's appropriate for this kind of investigation.
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.
RE: Number of Load Tests Required for Structural Significance
https://www.miamidade.gov/building/library/guideli...
RE: Number of Load Tests Required for Structural Significance
You may want to try searching ASCE's archives (in their Journals and the Structures Congress). Seems to me like I've seen some testing done on mullions over the years. It might get you close to a standard if they establish (with confidence) a limit.
RE: Number of Load Tests Required for Structural Significance
RE: Number of Load Tests Required for Structural Significance
RE: Number of Load Tests Required for Structural Significance
Haven't but you're right, the FL example may yield some good parallels.
The very same. Link
I've got one. I'll scan it for potential usefulness.
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.
RE: Number of Load Tests Required for Structural Significance
RE: Number of Load Tests Required for Structural Significance
RE: Number of Load Tests Required for Structural Significance
See if any of your client's competitors have ICC reports, and take a look at what evidence they submitted. That might give you an idea of the standard of care.
You could also call up some labs that do the ASTM tests and ask what other people may have done.
It looks like wall assemblies might just see proof loading as standard practice?
If you want to go with a formalized analysis, S136-16 Chapter K has a simplified method of determining resistance factors that are compatible with US LRFD and Canadian LSD load factors. It's still a bit involved, but easier than starting from scratch on the statistics. Read the commentary for that section as well. It's obviously geared towards cold formed steel, but I've thought about using it before and the method is pretty well generalized. It takes the number of tests into account as well as the variability. My only worry is that their assumptions are based on the load variation for a Live+Dead combination, whereas you might be designing this based on a Wind case. There are some references in the commentary though that it says might be useful for getting revised simplified assumptions for different load conditions.
RE: Number of Load Tests Required for Structural Significance