IJMC - Basic Research
You know, I just have to wonder about the experiments some of the
scientists mentioned below used to test their theories. Anyone want to
become a volunteer subject for the next set? -dave
---------- Forwarded message ----------
From: David Aronstein <daron@optics.rochester.edu>
Subject: Basic Research
If you aren't in the mood for humor best suited for a hyperactive, overly
hormonal 12 year old... perhaps this letter is best deleted now without
further reading.
I'm usually a good person, but studying all day, every day, in the library
over the last few weeks has made me a bit loopy.
I have a favorite little nook in the library, way in the back, past all
of the shelves of scientific journals. As I wander over to my special
spot, I let my eyes wander over all of the journals I pass. They have
titles like "Journal of Physics and Chemistry of Solids" or "Wildlife
Review" or "Selected Water Resources Abstracts" or even the "IEEE
Transactions on Information Theory."
Today I took a different route to my study chateau. I passed a different
set of bound journals, each one beckoning me with a new and exotic title.
Through the corner of my eye, I saw it. Could it be? Yes, yes it is. I
knew this was going to be an interesting experience. There it was:
"The Journal of Lubrication Technology."
I was intrigued.
I was fascinated.
I grabbed the latest bound volume.
There were two articles in particular that really impressed me.
The first:
"Interactions Between Dynamic Normal and Frictional Forces During
Unlubricated Sliding"
by A. Soom and C. Kim.
The first sentence says it all:
"When unlubricated surfaces slide over one another at speeds of a few
centimeters per second or faster, the generation of audible sound usually
accompanies the sliding process."
Moving on, I then found the Holy Grail of lubrication technology:
"Experimental Investigation of the Effect of System Rigidity on Wear and
Friction-Induced Vibrations."
by V. Aronov, A. F. D'Souza, S. Kalpakjian, and I. Shareef.
This is full of fascinating little gems, all from the Introduction:
"Self-excited vibrations of the stick-slip type have been studied by
several investigators in the past [1]."
"In the study of Brockley and Ko [5], as the sliding speed was increased
further, it was observed that there exists another critical speed at
which a different type of self-excited vibrations are induced."
"Yokoi and Nakai [6] also observed quasi-harmonic vibrations which they
named 'squeal.'"
"Bhushan [7] employed a glass slider, sliding over a rubber stave with
water lubrication. He observed two types of friction-induced vibrations,
namely, low frequency oscillations which he has named 'chatter' and high
frequency oscillations which he has named 'squeal.'"
"Generally, squeal was generated at low normal loads and high speeds,
whereas chatter was generated at high load and low speed or very high
load and any speed."
and finally...
"Usually it can be expected that any type of friction induced vibrations
will cause damage to the surface and result in excessive wear."
These papers just remind me again how basic research can prove to be
useful in making life better for all humanity.
--david
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