re:Re: Re: vibration damping materials

the esteemed Les Watts writes:

>I would like to recommend Dr. Slocums book "Precision Machine Design".
>It's pretty much the bible on designing machine tools, and it has sections
>on viscous and inertial damping of them. It belongs in the library
>of anyone building such things. In general it has very little math, but the
>sections on damping have a lot, although it is not difficult. It can

explain

>such things better that I can in a short post.

thanks for the tip. I just ordered this book on Amazon and hope to learn
from it in a few days.

A new project involves holding relative positions of components to better
than 100 nm while a large boom is happening nearby. Frankly, I had no idea
how to do this in anything other than a brute force way.

Do you know of resources on ultra stable materials? Telescope mirror makers
have worked on this problem quite a bit, I wonder if there are others with
similar needs and analytic skills?

Telescope makers like glass/ceramic materials. Fabrication of this stuff is
no picnic. It would be interesting to see how cast iron and granite compare
in stability, both thermal and in the various elastic and inelastic
deformations.

There was a mirror maker a few years ago (don't know if they are still
around) who made mirrors by sandwiching short lengths of borosilicate glass
tubing packed tightly between sheets of the same borosilicate glass. When
heated, soft glass tubing expanded to make hexagons and fused to the face
plates. The internal pressure in the hexagons kept the faceplates from
sagging (much). The air between the glass tubes escaped through properly
spaced holes. This made a very light stiff mirror. Expansion was rather
high compared to some of the better materials though.

regards-
Elliot B.