Re: Need simple equations for vibration motion

On 13 Jan 2006 10:27:22 -0800, "dave.harper" <dave.harper@xxxxxxxxx>
wrote:

>
>Brian Whatcott wrote:
>> Not enough data.
>> Do this. Apply a force F to the center of the diaphragm and measure
>> the displacement D. If you measure the force in newtons and the
>> displacement in meters, then the force times the displacement is the
>> work supplied in joules.
>> Supposing the surface would take as much work to move in the other
>> direction too, a cycle would need at least 2 X F X D joules.
>
>> I have blithely ignored resonance which would multiply the
>> displacement depending on the Q and I have blithely ignored other
>> loading like air or fluid damping which would reduce the displacement
>> and I also ignored innumerable other refinements like mounting
>> compliance. But you wanted simple.....
>
>I know that's a simplified calc, but I think that's a big
>underestimate. 2 x F x D assumes that all energy applied to the plate
>disipates after each half cycle. Realistically, you could displace the
>plate once and release it, and it will vibrate more than a half-cycle.
>Stored energy is not lost.
>
>Dave


Quite so

Brian Whatcott Altus OK
.

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