Esther & Fester Bestertester wrote:

See no n.g. for adhesives & epoxies, so if there's a better forum for this,
just point me to it.

I need an epoxy that is strong to the point of brittle. I want no flex; it
has to transmit vibration as close to 100% as possible.

Am I looking for a high Shore Hardness value? That's what Devcon uses in its
data sheets to specify hardness.

I believe that (Shore) is a measure of resistance to indentation. In
other words, pressure. You might need something else, depending on which
direction the vibration is acting with respect to the surface. A
pressure wave will result in both pressure and tensile stresses on the
adhesive. A shear wave will result in (duh) shear stresses.

In addition, you need to define what you mean by 'transmit vibration'.
I'm not a mechanical guy, but I'd be willing to bet that the problem of
maximizing mechanical energy transmission is analogous to that of
maximizing electromagnetic energy transmission. That is: It is optimal
when the impedance (modulus of elasticity?) is closely matched and
energy reflection is minimized.

The strength of the adhesive only becomes important if the amplitude of
the vibration approaches the strength limit of the bond.

This appears to be the sort of problems that people designing sonar
transducers have to deal with.

--
Paul Hovnanian
------------------------------------------------------------------
What if no one ever asked a hypothetical question?