Basic nomenclature question
Basic nomenclature question
(OP)
What does or where did the subscript "a" come from for required strength in ASD design? As in Ma, Ra, Pa, etc.
Shouldn't it be called "r" instead or something so people don't confused it with "allowable"?
Shouldn't it be called "r" instead or something so people don't confused it with "allowable"?






RE: Basic nomenclature question
Dave
Thaidavid
RE: Basic nomenclature question
RE: Basic nomenclature question
Subscript n (Rn) is the nominal capacity. Essentially the capacity with no adjustment for LRFD or ASD.
Subscript a (Ra) is the required allowable capacity for ASD. Ra ≤ Rn/Ω.
Subscript u (Ru) is the required ultimate capacity for LRFD. Ru ≤ φRn.
I can see your point, though. You would think subscript r would be used for "required". This is done somewhat, if you look at chapter H for combined forces in AISC 360 you see that Rr is the "required" strength for LRFD or ASD.
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American Concrete Industries
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