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RE: Wood continuous beams

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Ed,

I would look very closely at the validity of the wood lateral bracing 
limitation.  A number of years ago, I found that it permitted design stresses 
in very slender unbraced flexural members.  Using the maximum limitation in 
the formula and looking at a 2 X 12, I came up with it permitting design 
stresses in a 2 X 12 with an lsube greater than 43', absurd at even half that 
length.

Going to the original published paper for the formula, it appears (to me) 
that a gross error was made in the shear modulus.  Private correspondence 
with (then) AF&PA indicated that they could not find the original researchers 
to confirm the results and did not know whether they were living or dead.  
The research was performed in British Columbia, Canada, by two researchers, 
one of whom was with a GLB fabricator.

A. Roger Turk, P.E.(Structural)
Tucson, Arizona

Ed Tornberg wrote:

. > Being aware that it's standard practice to apply moment redistribution
. > to continuous concrete beams,  is there any information out there on the
. > possibility of applying moment redistribution to continuous wood beams?
. > I'm not pretending to think that wood forms plastic hinges like
. > concrete, but I'm wondering if the creep characteristics of wood can
. > produce a similar, although lesser, effect.  The member in question is a
. > 24" x 1.5" LVL.
 
. > Ed Tornberg, PE 
. > Blazer Industries, Inc.

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