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<DIV><FONT color=#808000>Comments below:</FONT></DIV>
<DIV><FONT color=#808000></FONT> </DIV>
<DIV><FONT color=#808000>Terry Farrell</FONT></DIV>
<DIV> <SPAN id=__#Ath#SignaturePos__></SPAN> </DIV>
<DIV>----- Original Message -----
<DIV>From: "Richard Brekne" <<A
href="mailto:Richard.Brekne@grieg.uib.no">Richard.Brekne@grieg.uib.no</=
A>></DIV>
<DIV>To: <<A =
href="mailto:pianotech@ptg.org">pianotech@ptg.org</A>></DIV>
<DIV>Sent: Thursday, August 01, 2002 4:52 AM</DIV>
<DIV>Subject: Re: CA gluing Grand Pinblocks....My take on it/ Richard
Brekne</DIV></DIV>
<DIV><BR></DIV>
<DIV>> Farrell wrote:<BR>> > <BR>> > Yeah, we are closer. =
My
terminology may be less than ideal. I think the proper term to use =
>rather
than shear force is shear stress. My terms are coming largely from my =
graduate
>studies in structural geology (a few years back now!) - but forces =
are
forces, and stresses >are stresses. <BR>> <BR>> I dont think I =
have a
problem separating shear force with<BR>> stress here. Thats cool. I =
think
actually thats the<BR>> distinction I am making by insisting on =
clarifying
the<BR>> difference in using the words "between" an "on" in =
this<BR>>
context. (ie shear force between, and shear force on.) <BR>> <BR>> =
>If
it is not compression, and it is not tension, and you are talking about =
two
parallel >planes of reletive motion (or force), then you have a shear =
stress.<BR>> > <BR>> > That is, of course, if I remember
correctly! ;-)<BR>> <BR>> Shear stress is not just two =
parallel
planes of relative<BR>> motion or force... this is shear only =
when the
stress<BR>> itself is parallel to those planes. Says much the same
thing<BR>> as you do above I guess, but perhaps makes it easier =
to<BR>>
avoid misunderstanding ?</DIV>
<DIV><BR><FONT color=#808000>I don't follow 100%.</FONT></DIV>
<DIV> <BR>> In the case two plates coupled by a nail, the nail =
will
be<BR>> under shear stress, and whatever shear stress is apparent =
on<BR>>
the plates is only at the nail, exactly at and parallel to<BR>> the =
cross
section of the nail. Yes ?</DIV>
<DIV><BR><FONT color=#808000>Yes. This assumes the plates are coupled =
together
only at the nail.</FONT></DIV>
<DIV> <BR>> In the case of two plates coupled by being pressed
together,<BR>> fricton takes the place of the nail above and the =
result
is<BR>> shear stress exerted ON the two surfaces. The amount =
of<BR>> shear
stress here is dependent on the net angle of the sum<BR>> of the =
forces
involved... no ?? (We use vectors for this<BR>> kinda thing eh ? =
)</DIV>
<DIV> </DIV>
<DIV><FONT color=#808000>100% Yes. This is the elementary =
example. This is
just like two rocks trying to slide past one another - shear =
stress on the
faces of the two rocks.</FONT><BR> <BR>> In the case of two =
blocks of
wood pushed together.... while<BR>> this has two parallel planes of =
force
(not motion) the force<BR>> is applied perpendicular to the planes
involved... ie<BR>> compression (tensil ?) stress on the two surfaces =
of
the<BR>> blocks.<BR>> <BR>> <BR>> <BR>> > <BR>> =
> Terry
Farrell<BR>> > <BR>> Cheers !<BR>> <BR>> RicB<BR>> =
<BR>>
"The greatest impediment to real communication may in<BR>> reality be =
the use
of language"<BR>> anon.<BR>> </DIV></BODY></HTML>