huangyhg

aisc13th, web crippling at beam ends question
there is a conflicts in aisc-13th: on page 9-19, web crippling at beam ends, at bottom table, for distance x>=d/2, only r3 is multiplied by 2, r4 does not apply factor 2. but on table 9-4 from page 9-38 to 9-51, both r3 and r4 are to be multiplied by 2 when distance x>=d/2.
table 9-4 conflicts with formulas on page 9-19.
is table 9-4 wrong?
robert - if you look at the actual formulae for r3 and r4 on page 9-18 of the manual - you can see that r4 is indeed 1/2 of that indicated in the specification for the second term of equation j10-4.
i think the equation shown at the bottom of page 9-19 is missing a couple of parentheses. if you look at section j10.3 it is obvious that equation j10-4 uses a 0.8 term on the whole vs. the other equations.
probably should notify aisc about this - it isn't in the latest errata that i have for the manual.
jae:
comparing formulas in 9-18 with formula j10-4. it seems r4 term in page 9-19 bottom formulas does miss a factor 2. right?
yes it looks like it to me.
as i said...if you add a parenthesis around everything but the 2 then it works ok.

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