Viscoelastic material for damping high frequencies?

[GMarsh]

Hello all,

I would like to know if there is any viscoelastic material that is more suited or designed to damp high frequencies - 15000 - 16000 Hz ? I mean having loss factor near to 1 around this frequency range? Most of the commercially available tapes are designed for 1000 Hz range.

Thank you

Geoff

 

[Demon3]

I don't have the exact answer but do have some clues.

Damping is achieved by lossy materials (materials that are soft but inelastic). I.e. in the DMA curve they have a high tan delta value (loss factor) in the frequency range you're interested in. Usually higher mass is good too, for example using a dense filler like barium sulfate or magnetite.

At higher frequencies materials behave more stiffly and elastically. So, you need to use a material with very low glass transition temperature (Tg). I know you can buy Sorbothane mats. Do they work at that frequency?

Chris DeArmitt - PhD FRSC CChem

 

[btrueblood]

Are you damping a one-time event (shock) or a continous 16 kHz frequency? I know that, depending on thickness, epoxy can provide reasonable damping at ultrasound freq. At 2-10 kHz, we saw good shock damping with thin silicone elastomers from Lord Chemicals. Big hint on that last one there - they are experts on the subject.

 

[GMarsh]

Thank you for all the responses.

Presently I am using 3M ISD 112 tape whose loss factor droops to 0.3 by 10kHz. It's greatest loss factor is around 1kHz.

It is not a shock event, but a forced vibration at 16kHz.

Demon3 - Can you please explain what you mean by 'higher mass is good too'. Do you mean to say that instead of traditional 5% of vibrating mass, should we go for 10 or 20% while designing tuned mass?

I am actually looking for something sticky tape - like that of 3M Viscoelastic tapes. If I get non-sticky polymer I may have to again think of using some adhesive to mount it on structure.

I will contact Sorbothane and Lord Chemicals. Thank you for your suggestions.

Kind regards

 

[Demon3]

By adding mass I mean that usually such compounds are filled with dense particles to increase their mass. The more mass you have to vibrate, the more energy it takes.

Chris DeArmitt - PhD FRSC CChem

 

[GMarsh]

Yes, but theoretically one should add damping also along with mass to damp out the split modes caused due to tuned mass. So I am looking to add damping tape which has highest loss factor in that frequency zone of 16kHz.

 

[Demon3]

That's what I said. You choose a lossy, damping material and add mass by filling it with dense particles.

Chris DeArmitt - PhD FRSC CChem