RE: Nail Slip

• To: <seaint(--nospam--at)seaint.org>
• Subject: RE: Nail Slip
• From: "Bill Allen" <Bill(--nospam--at)AllenDesigns.com>
• Date: Thu, 17 Aug 2000 06:57:05 -0700
```John-

Maybe when solving this equation by hand, the problem with the units is not
apparent, but it is when using something like Mathcad. This is why I had to
include a "12" in the denominator in the first and third terms in my
example.

More importantly, I invite attention to the results of the sample I posted
on the web. Once again, see:

http://www.allendesigns.com/sw/shearwalldeflections.htm

If you notice, this is a fairly "normal" (i.e., moderately loaded) shear
wall. Even though the aspect ratio meets Code (2:1), the deflection is
(slightly) excessive (0.0266h vs. an allowable of 0.025h). This is mostly
due to the use of a HD instead of a PHD or some other device which minimizes
hold down deflections.

Imagine a highly loaded shear wall.

Thanks,

Bill Allen, S.E. (CA #2607)
ALLEN DESIGNS
Consulting Structural Engineers
Laguna Niguel, CA
http://www.AllenDesigns.com
V (949) 365-5696
F (949) 249-2297

||-----Original Message-----
||Sent: Wednesday, August 16, 2000 11:16 PM
||To: seaint(--nospam--at)seaint.org
||Subject: Re: Nail Slip
||
||
||Bill, it is dimensionally consistent. There are factors
||within the constants for
||each term that account for the apparent inconsistencies. Same
||applies to
||diaphragm deflection equation.
||John Rose/APA
||
||Bill Allen wrote:
||
||> Nels-
||>
||> As Dennis Wish once pointed out, this equation (along with
||others) is not
||> dimensionally consistent. I worked an example in Mathcad
||and converted it to
||> html. You can view this example at:
||>
||> http://www.allendesigns.com/sw/shearwalldeflections.htm
||>
||> I hope this helps in making this equation clearer.
||>
||> Regards,
||>
||> Bill Allen, S.E. (CA #2607)
||> ALLEN DESIGNS
||> Consulting Structural Engineers
||> Laguna Niguel, CA
||> http://www.AllenDesigns.com
||> V (949) 365-5696
||> F (949) 249-2297
||>
||> ||-----Original Message-----
||> ||From: Nels Roselund [mailto:n.roselund(--nospam--at)worldnet.att.net]
||> ||Sent: Tuesday, August 15, 2000 6:08 PM
||> ||To: seaint(--nospam--at)seaint.org
||> ||Subject: Re: Nail Slip
||> ||
||> ||
||> ||Mike,
||> ||
||> ||Thanks for pointing me to the answer.
||> ||
||> ||Your explanation [in the Archives], that the implied units of
||> ||the constant
||> ||in the nail-slip term of the equation is 1/ft, seems to make
||> ||sense.  It
||> ||gives the nail slip term a value of 1/12  of the result I got
||> ||by making the
||> ||Table value of en unit-less.  It also gives a result that
||makes the
||> ||contribution of nail-slip to the total deflection small
||> ||rather than the
||> ||major component of shear wall deflection.
||> ||
||> ||If the implied units of the constant were to be taken as
||> ||1/in, the result
||> ||would be the same as making en unit-less.
||> ||
||> ||Is your use of an implied value of 1/ft rather than 1/in based on
||> ||documentation, or on what you know of the derivation of
||the deflection
||> ||equation?  Or is your explanation based on what you, too,
||> ||found to give the
||> ||most sensible results?  I'd like to know that there is
||> ||documentation and how
||> ||to find it.  I don't like to have to  use magic formulas.
||> ||
||> ||Nels Roselund
||> ||Structural Engineer
||> ||
||> ||
||> ||-----Original Message-----
||> ||From: Mike Valley <mtv(--nospam--at)skilling.com>
||> ||To: seaint(--nospam--at)seaint.org <seaint(--nospam--at)seaint.org>
||> ||Cc: n.roselund(--nospam--at)worldnet.att.net <n.roselund(--nospam--at)worldnet.att.net>
||> ||Date: Tuesday, August 15, 2000 3:32 PM
||> ||Subject: RE: Nail Slip
||> ||
||> ||
||> ||>This was discussed on the list in July of 1999.  I
||posted on 7/8 and
||> ||>7/15.  The archives contain the info.
||> ||>
||> ||>- - - - - - - - - - - - - - - - - - - - - - - - - - - -
||- - - - - - -
||> ||>Michael Valley, P.E., S.E.                   E-mail:
||mtv(--nospam--at)skilling.com
||> ||>Skilling Ward Magnusson Barkshire Inc.
||Tel:(206)292-1200
||> ||>1301 Fifth Ave, #3200,  Seattle  WA 98101-2699      Fax:
||       -1201

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