] [Thread] [Date] [Author]

["Bill Allen, S.E." <ballense(--nospam--at)pacbell.net>]

The garbage below is not (I believe) due to HTML
encoding since my e-mail viewer is HTML capable. This stuff is coming from
ONE person ("T") and shouldn't be considered a system wide problem.

Further, wouldn't Mr. Arenson's post (copied below) have looked better if the equations were RTF formatted?

In the classic example of a pinned-rotationally fixed column with a horizontal spring at the fixed rotation end,

P*delta = Q*L  and Q = k*delta
where Q= the force in the spring , k=stiffness the of spring, and L= Length of the column

The required stiffness for effective length=1.0 is k=Pcr/L

Pcr for elastic buckling is pi^2*E*I/L^2

Therefore, considering the stiffness of the tension member to be k=48EI/L^3, for the tension member to brace the
compression member, pi^2>48     -of course this is never the case. It does show that the non-compression diagonal
has some contribution to reducing the effective length of the compression member even without including the effect of
tension restoring force.

Thus far, the analysis has ignored the effect of tension in the tension member.  P*delta= Q*L for the tension member
as well as the compression member- this time the spring force is in the opposite direction than for the compression
member.  Since Q tension = Q compression , wouldn't the tension brace always provide enough restraint to provide
for N=2 buckling?  N=2 buckling corresponds to K=0.5- the same result obtained by adding radii of gyration.

There is the issue of initial out-of-straightness from fabrication and erection tolerance that will cause the real K to be
greater than 0.5.

I guess I'm an optimist and think K=0.67 is o.k.

Another note: I never referred to the contribution of the out of plane gusset plates to the end restraint of the members
in the system.  Of course, there is some small restraint that varies depending on the configuration of the connections
and member types

Regards,
Bill Allen

FLew98 wrote:

In a message dated 98-03-12 15:44:29 EST, you write:

> -----Original Message-----
>  From: Bill Cain, S.E. +ADw-bcain+AEA-ebmud.com+AD4-
>  To: seaoc+AEA-seaoc.org +ADw-seaoc+AEA-seaoc.org+AD4-
>  Date: Thursday, March 12, 1998 8:48 AM
>  Subject: Re: +ACY- Characters from Listserver
>
>
>  +AD4-At 07:23 3/12/98 -0800, you wrote:
>  +AD4APg-
>  +AD4APg------Original Message-----
>  +AD4APg-From: T +ADw-vicpeng+AEA-vtcg.com+AD4-
>  +AD4APg-To: seaoc+AEA-seaoc.org +ADw-seaoc+AEA-seaoc.org+AD4-
>  +AD4APg-Date: Thursday, March 12, 1998 7:19 AM
>  +AD4APg-Subject: Re: International Collecting on Invoices
>  +AD4APg- .......
>  +AD4APg- Does any one know why +ACIAJgAi- is popping up for characters such
> as
>  +AD4APg-amphersands and punctuation marks?  And is this happening to the +
> AD4APg-posting
>  or just me?
>  +AD4APg-
>  +AD4APg-Thor Tandy  P.Eng
>  +AD4APg-Victoria BC
>  +AD4-
>  +AD4-
>  +AD4AWw-Bill Cain+AF0- I'm getting them too+ACE-
>
>
>
>  This posting I entered it as +ADwAKw-ACY-+AD4- and it came out correct as
> the
>  amphersand+ACEAIQAhACEAIQAhACEAIQ-  I feel like Leonard da Vinci but
without
> my mirror.
>
>  AAAHHHHHH+ACEAIQ-

Folks,

Previous postings have made it quite clear that many subscribers on this
listserv cannot be html-compliant, and for them html-encoded postings show up
with extraneous garbage.  The example above is typical.   Such nonsense are
increasingly showing up ever since someone suggested tinkering with the
settings on our e-mail programs to display and submit html-encoded e-mail.

Recent postings indicate that even fans of html agree we should remain with
ascii e-mail for now.  This message is aimed at those of you who have tinkered
with your settings:  PLEASE check that you have returned your settings back to
the default ascii format.

Frank Lew, SE
Orinda, CA
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