re:Re: re:Re: RE:Re: Re: no thrust bearing - simple design ?

Hoyt,
I think you are unnecessarily restricting the use of a word in common use.
Stiffness has several meanings including stiffness of a body, as well as of
a differential unit of volume. Consulting a reference work makes this quite
clear. When in doubt as to which of several meanings might be intended a
look at the context is in order.

Some of us in specialized fields take a word in common use and exclude all
but one meaning- I've been guilty of that one. A technical definition of
light is radiation that is detected by the eye. Had a disagreement about
whether infrared could properly be called light. This is regarding language
of a patent (it was granted), so what one says really matters. In the end
we just dropped the distinction, since what was meant was clear from the
context.

There are many of us trained and working in science on this list, it
certainly isn't a great distinction.

And yes, preload is one type of load stiffening. It wouldn't be a term I'd
use to describe when happens with walls of a pressurized vessel (my
example), but to each his own.

regards-
Elliot B.

>At 10:21 PM 4/22/03 -0700, you wrote:
>>Hoyt, load stiffening is a very common phenomena. I wasn't talked about
>>elastic stiffness of a differential unit of volume but rather the

stiffness

>>of a long screw or rod.

>Stiffness is a material characteristic and it isn't affected by preload, in
>tension or compression. Sorry if that sounds anal, but I was trained in
>science and worked in a testing environment. What you are describing is in
>fact simple preload, which does have the effects you described. All I want
>you to do is be aware of the distinction, so next time someone like me
>won't see that error, and he won't have to chime in.

>>enough tension on the rod will prevent it from going into compression,

thus

>>it will be stiffened.

>Preloaded. HAGO.

>Regards, Hoyt McKagen

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