Need a book? Engineering books recommendations...
Return to index: [Subject] [Thread] [Date] [Author]
Re: Load Capacity of a Holddown Post as a Compression Member
[Subject Prev][Subject Next][Thread Prev][Thread Next] To: <seaint(nospamat)seaint.org>
 Subject: Re: Load Capacity of a Holddown Post as a Compression Member
 From: "S. Gordin" <scgordin(nospamat)hotmail.com>
 Date: Thu, 5 Aug 2004 22:59:16 0700
Thor,
This problem is discussed in
Timoshenko's "Theory of Elastic Stability." With remarkable yet usual for him elegancy and thoroughness,
Timoshenko shows that the critical force for a column loaded with concentrated
compressive forces at the ends is more than 3 times higher than for a
similar column loaded by the equivalent distributed force. Of course, this
is an analytical elasticbuckling solution...
I did not follow this thread from the
very beginning, so the following may not exactly address the nature of the
original post. Still, I do not believe that the compressive force in
the shear wall is resisted by the end post.
Indeed, we  more often then not
 assume the horizontal diaphragms (glued and nailed) to be "flexible"; then why
not do the same for vertical  nailed only  diaphragms? If so, the
rockingrelated compression is resisted by almost all studs of the shear
wall, with some sort of distribution (say, triangular or similar)
of force away from the tension post (holdown).
BTW, this may shed some light on the effect of a uniformly distributed
moment due to onesided plywood application to the end post. A combined
action of such distributed moment and the aforementioned quite unfavorable
loading by the distributed compressive force should most likely result in
spectacular failures of compressive posts during earthquakes. AFAIK,
that rarely  if ever  happens. This means that both "m" and "qc"
are indeed distributed along the substantial portion of the length of the
shear wall.
Steve Gordin, SE

 References:
 Re: Load Capacity of a Holddown Post as a Compression Member
 From: Mattesons
 Re: Load Capacity of a Holddown Post as a Compression Member
 Prev by Subject: Re: Load Capacity of a Holddown Post as a Compression Member
 Next by Subject: Re: Load Capacity of a Holddown Post as a Compression Member
 Previous by thread: Re: Load Capacity of a Holddown Post as a Compression Member
 Next by thread: Re: Load Capacity of a Holddown Post as a Compression Member
 About this archive
 Messages sorted by: [Subject][Thread][Author][Date]