ASCE 7 Chapter 13 - High vs Limited vs Low Deformability

[WS6]

Went down a rabbit hole recently on the chapter 13 provisions for architectural components that I'm looking for some background on. Table 13.5-1 lists coefficients for architectural components and classifies Other Flexible Components as either high, limited, or low deformability. These delineations are then defined in 11.2 based on the ratio of the ultimate deformation to the limit deformation, also defined in 11.2. These deformations seem relatively straightforward to calculate, but the definition of high-deformability in 11.2 states that the element's "deformability is not less than 3.5 where subjected to four fully reversed cycles at the limit deformation".

This last sentence seems a bit nebulous and is throwing me for a loop. For argument's sake, let's say your system is statically determinant and remains elastic at the limit deformation, then cyclic loading should have no impact on the deformability. Presumably, if you had an indeterminate system, portions could yield under cyclic loading without forming a mechanism, which could increase the deflection at the limit deformation thereby reducing your deformability ratio. Maybe I'm overthinking this one. Either way, going about calculating this seems rather tedious.

I haven't found any further discussion in the commentary or in ATC 120/ NIST GCR 13-917-23. Does anyone have any documentation or background/insight on these definitions? It seems like they first made their way into ASCE 7 in 95/98.