Re: Need simple equations for vibration motion


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

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Relevant Pages

  • Re: Need simple equations for vibration motion
    ... >> displacement in meters, then the force times the displacement is the ... a cycle would need at least 2 X F X D joules. ... >plate once and release it, and it will vibrate more than a half-cycle. ... Brian Whatcott Altus OK ...
    (sci.engr.mech)
  • Re: Where did the extra mass come from?
    ... is no significant deformation that would support large displacement. ... Hey, Stuart, .. ... he's using the language of Plate Tectonics ... Of course it matters - as Florian well knows and keeps ...
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  • Re: Need simple equations for vibration motion
    ... >I need to estimate the amount of displacement vibration will cause. ... >Find the displacement of the maximum displacement of the diaphragm. ... a cycle would need at least 2 X F X D joules. ...
    (sci.engr.mech)