knoTerminology ( Terminology)

[SORRY FOR THE SUBJECT CHANGE, BUT DEJANEWS IS MISBEHAVING, AND THIS IS ONE
WAY A TIRED POSTER CAN PUT BOTH DEJANEWS & HIMSELF TO SLEEP. (I HOPE :-) ]

"Doug" wrote :

"ben" wrote:
........
Richard M Chisholm has tried to define these things in:

Thanks Ben, I read this also and found it very helpfull. However I hadn't
seen these terms in formal use before and thought it might have been "The
Chisholm Classification" rather than a more widely used Classification. I
have also seen the term "Knot Slacking" used to describe the phenomenon but
again only by one or two people.

Well, there isn't any formal practical-knots discipline (and too much
un-discipline)-: so, yes, those are Dick's terms & definitions.

For the question at hand, I don't agree that "stability" is what's at
stake: Dick defines that pretty much as knot integrity under abnormal
loading (which could be viewed differently: i.e., as a different "knot"[1]);
but what you describe is simply a lack of security--the knot is loosening.
(I assume that light or no loading is quite "normal".)

[1] Is a sheet bend that is loaded on its end "abnormally" loaded (and
if it fails, "unstable"), or is it a Lapp Bend (and if it fails,
"insecure")? You can define terms according to what perspective
will be most helpful.

Designing a test for such properties as loosening ("slacking" has a nice
jocular tone ) is an interesting challenge. Maybe it would be convenient
to attach test specimens to some dependably, regularly vibrating device
(hospital laundry machines; paint mixers (wow!)?

As for the Chisholm papers, these are works in progress.
(I know that I owe some comments.) Perhaps from the much more refined world
of medicine (and the requisite background sciences) will come better terms
to use here?

--dl*
====

"Dan Lehman" wrote in message
om...
...... Maybe it would be convenient
to attach test specimens to some dependably, regularly vibrating device
(hospital laundry machines; paint mixers (wow!)?

You must be psychic! A collegue and I recently did this to investigate this
failure mode of suture knots. We used 3/0 suture material (it typically has
a load to failure of several kilograms) looped around a piece of bath
sponge and the 2 ends tied a standard surgical knot ( 2=1=1 ). We then put
them in a washing machine on "rinse cyle" for 10 minutes. Silk, cat gut,
braided polyester, polyethelene all remained intact but a number of
"specialty" materials Caprosyn, Dexon, Monosof, Monocryl had a very high
failure rate - 100% in some cases! I was hopeing there would be a more
sophisticated way of testing this though. The machines for testing failure
under load in the laboratory cost tens of thousand of dollars


As for the Chisholm papers, these are works in progress.
(I know that I owe some comments.) Perhaps from the much more refined
world
of medicine (and the requisite background sciences) will come better terms
to use here?

I have researched the published literature in the surgical sciences and
strangely I can find no references at all to this mode of failure
(unravellingvelling of knots under light load). Yet my experience tells me
it is a common mode of failure in practice. There is a tendency atribute
failure of surgical knots to errors in tying technique but I think the
material properties of the suture material play a big part. For example
different knots may be required for soft pliable material like silk as
opposed to material like nylon.

Any way Richard M Chisholms description of the various failure modes has
helped a lot in clarifying my thinking on this subject.

Doug Turner

"Dan Lehman" wrote in message
om...
...... Maybe it would be convenient
to attach test specimens to some dependably, regularly vibrating device
(hospital laundry machines; paint mixers (wow!)?

You must be psychic! A collegue and I recently did this to investigate this
failure mode of suture knots. We used 3/0 suture material (it typically has
a load to failure of several kilograms) looped around a piece of bath
sponge and the 2 ends tied a standard surgical knot ( 2=1=1 ). We then put
them in a washing machine on "rinse cyle" for 10 minutes. Silk, cat gut,
braided polyester, polyethelene all remained intact but a number of
"specialty" materials Caprosyn, Dexon, Monosof, Monocryl had a very high
failure rate - 100% in some cases! I was hopeing there would be a more
sophisticated way of testing this though. The machines for testing failure
under load in the laboratory cost tens of thousand of dollars


As for the Chisholm papers, these are works in progress.
(I know that I owe some comments.) Perhaps from the much more refined
world
of medicine (and the requisite background sciences) will come better terms
to use here?

I have researched the published literature in the surgical sciences and
strangely I can find no references at all to this mode of failure
(unravellingvelling of knots under light load). Yet my experience tells me
it is a common mode of failure in practice. There is a tendency atribute
failure of surgical knots to errors in tying technique but I think the
material properties of the suture material play a big part. For example
different knots may be required for soft pliable material like silk as
opposed to material like nylon.

Any way Richard M Chisholms description of the various failure modes has
helped a lot in clarifying my thinking on this subject.

Doug Turner

"Dan Lehman" wrote in message
om...
...... Maybe it would be convenient
to attach test specimens to some dependably, regularly vibrating device
(hospital laundry machines; paint mixers (wow!)?

You must be psychic! A collegue and I recently did this to investigate this
failure mode of suture knots. We used 3/0 suture material (it typically has
a load to failure of several kilograms) looped around a piece of bath
sponge and the 2 ends tied a standard surgical knot ( 2=1=1 ). We then put
them in a washing machine on "rinse cyle" for 10 minutes. Silk, cat gut,
braided polyester, polyethelene all remained intact but a number of
"specialty" materials Caprosyn, Dexon, Monosof, Monocryl had a very high
failure rate - 100% in some cases! I was hopeing there would be a more
sophisticated way of testing this though. The machines for testing failure
under load in the laboratory cost tens of thousand of dollars


As for the Chisholm papers, these are works in progress.
(I know that I owe some comments.) Perhaps from the much more refined
world
of medicine (and the requisite background sciences) will come better terms
to use here?

I have researched the published literature in the surgical sciences and
strangely I can find no references at all to this mode of failure
(unravellingvelling of knots under light load). Yet my experience tells me
it is a common mode of failure in practice. There is a tendency atribute
failure of surgical knots to errors in tying technique but I think the
material properties of the suture material play a big part. For example
different knots may be required for soft pliable material like silk as
opposed to material like nylon.

Any way Richard M Chisholms description of the various failure modes has
helped a lot in clarifying my thinking on this subject.

Doug Turner

"Dan Lehman" wrote in message
om...
...... Maybe it would be convenient
to attach test specimens to some dependably, regularly vibrating device
(hospital laundry machines; paint mixers (wow!)?

You must be psychic! A collegue and I recently did this to investigate this
failure mode of suture knots. We used 3/0 suture material (it typically has
a load to failure of several kilograms) looped around a piece of bath
sponge and the 2 ends tied a standard surgical knot ( 2=1=1 ). We then put
them in a washing machine on "rinse cyle" for 10 minutes. Silk, cat gut,
braided polyester, polyethelene all remained intact but a number of
"specialty" materials Caprosyn, Dexon, Monosof, Monocryl had a very high
failure rate - 100% in some cases! I was hopeing there would be a more
sophisticated way of testing this though. The machines for testing failure
under load in the laboratory cost tens of thousand of dollars


As for the Chisholm papers, these are works in progress.
(I know that I owe some comments.) Perhaps from the much more refined
world
of medicine (and the requisite background sciences) will come better terms
to use here?

I have researched the published literature in the surgical sciences and
strangely I can find no references at all to this mode of failure
(unravellingvelling of knots under light load). Yet my experience tells me
it is a common mode of failure in practice. There is a tendency atribute
failure of surgical knots to errors in tying technique but I think the
material properties of the suture material play a big part. For example
different knots may be required for soft pliable material like silk as
opposed to material like nylon.

Any way Richard M Chisholms description of the various failure modes has
helped a lot in clarifying my thinking on this subject.

Doug Turner

"Dan Lehman" wrote in message
om...
...... Maybe it would be convenient
to attach test specimens to some dependably, regularly vibrating device
(hospital laundry machines; paint mixers (wow!)?

You must be psychic! A collegue and I recently did this to investigate this
failure mode of suture knots. We used 3/0 suture material (it typically has
a load to failure of several kilograms) looped around a piece of bath
sponge and the 2 ends tied a standard surgical knot ( 2=1=1 ). We then put
them in a washing machine on "rinse cyle" for 10 minutes. Silk, cat gut,
braided polyester, polyethelene all remained intact but a number of
"specialty" materials Caprosyn, Dexon, Monosof, Monocryl had a very high
failure rate - 100% in some cases! I was hopeing there would be a more
sophisticated way of testing this though. The machines for testing failure
under load in the laboratory cost tens of thousand of dollars


As for the Chisholm papers, these are works in progress.
(I know that I owe some comments.) Perhaps from the much more refined
world
of medicine (and the requisite background sciences) will come better terms
to use here?

I have researched the published literature in the surgical sciences and
strangely I can find no references at all to this mode of failure
(unravellingvelling of knots under light load). Yet my experience tells me
it is a common mode of failure in practice. There is a tendency atribute
failure of surgical knots to errors in tying technique but I think the
material properties of the suture material play a big part. For example
different knots may be required for soft pliable material like silk as
opposed to material like nylon.

Any way Richard M Chisholms description of the various failure modes has
helped a lot in clarifying my thinking on this subject.

Doug Turner

"Dan Lehman" wrote in message
om...
...... Maybe it would be convenient
to attach test specimens to some dependably, regularly vibrating device
(hospital laundry machines; paint mixers (wow!)?

You must be psychic! A collegue and I recently did this to investigate this
failure mode of suture knots. We used 3/0 suture material (it typically has
a load to failure of several kilograms) looped around a piece of bath
sponge and the 2 ends tied a standard surgical knot ( 2=1=1 ). We then put
them in a washing machine on "rinse cyle" for 10 minutes. Silk, cat gut,
braided polyester, polyethelene all remained intact but a number of
"specialty" materials Caprosyn, Dexon, Monosof, Monocryl had a very high
failure rate - 100% in some cases! I was hopeing there would be a more
sophisticated way of testing this though. The machines for testing failure
under load in the laboratory cost tens of thousand of dollars


As for the Chisholm papers, these are works in progress.
(I know that I owe some comments.) Perhaps from the much more refined
world
of medicine (and the requisite background sciences) will come better terms
to use here?

I have researched the published literature in the surgical sciences and
strangely I can find no references at all to this mode of failure
(unravellingvelling of knots under light load). Yet my experience tells me
it is a common mode of failure in practice. There is a tendency atribute
failure of surgical knots to errors in tying technique but I think the
material properties of the suture material play a big part. For example
different knots may be required for soft pliable material like silk as
opposed to material like nylon.

Any way Richard M Chisholms description of the various failure modes has
helped a lot in clarifying my thinking on this subject.

Doug Turner

"Dan Lehman" wrote in message
om...
...... Maybe it would be convenient
to attach test specimens to some dependably, regularly vibrating device
(hospital laundry machines; paint mixers (wow!)?

You must be psychic! A collegue and I recently did this to investigate this
failure mode of suture knots. We used 3/0 suture material (it typically has
a load to failure of several kilograms) looped around a piece of bath
sponge and the 2 ends tied a standard surgical knot ( 2=1=1 ). We then put
them in a washing machine on "rinse cyle" for 10 minutes. Silk, cat gut,
braided polyester, polyethelene all remained intact but a number of
"specialty" materials Caprosyn, Dexon, Monosof, Monocryl had a very high
failure rate - 100% in some cases! I was hopeing there would be a more
sophisticated way of testing this though. The machines for testing failure
under load in the laboratory cost tens of thousand of dollars


As for the Chisholm papers, these are works in progress.
(I know that I owe some comments.) Perhaps from the much more refined
world
of medicine (and the requisite background sciences) will come better terms
to use here?

I have researched the published literature in the surgical sciences and
strangely I can find no references at all to this mode of failure
(unravellingvelling of knots under light load). Yet my experience tells me
it is a common mode of failure in practice. There is a tendency atribute
failure of surgical knots to errors in tying technique but I think the
material properties of the suture material play a big part. For example
different knots may be required for soft pliable material like silk as
opposed to material like nylon.

Any way Richard M Chisholms description of the various failure modes has
helped a lot in clarifying my thinking on this subject.

Doug Turner