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Re: FEMA 356 bare steel deck acceptance criteria

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Shear buckling, leaves the plate acting something like tension braces.
This concentrates the weld forces at the corners. I have not used the
equations for about 15 years. My references are storage. I can get to them
next trip to my greater molding library, but first wanted to say the
above.

David Merrick, SE

Dave Evans wrote:

> Two issues:
>
> 1. FEMA 356 acceptance criteria for bare steel deck diaphragms
> seem to be ambiguous...
>
> Para 5.9.1.4 says that diaphragms not governed by connections
> are deformation-controlled.  It directs the user to Table 5-5 for m-
> factors for "shear yielding and plate buckling."   It doesn't mention
> panel buckling.
>
> The commentary for 5.9.1.4 says that diaphragms controlled by
> "connections or panel buckling" are force-controlled.
>
> Table 5-5 gives a m-factor for "shear yielding or panel or plate
> buckling.".
>
> So...I conclude that...
>
> a. connection failure is force-controlled
> b. shear yielding is deformation-controlled
> c. general plate-like buckling of the whole diaphragm area is
> deformation-controlled
> d. FEMA356 is ambiguous regarding local panel buckling
>
> ...and the question is:   is local panel buckling force-controlled or
> deformation-controlled?  If it is force, then Table 5-5 must be wrong.
>  If it is deformation, then the commentary must be wrong.  And in
> either case, the referenced paragraph could be considered
> incomplete, since it doesn't mention panel buckling.
>
> 2. Second question(s):
>
> My 2nd Edition  SDI manual doesn't give equations for local panel
> buckling or shear yield strengths.  Does anyone have references
> that do?
>
> Thanks,
> Dave
>
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