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Im designing a model for Kelvin Method. Some of my calculation results are as follows:

  1. Radius of the membrane : 50 micron
  2. thickness of the membrane : 3.25 micron
  3. resonate frequency : 1.32MHz
  4. spring constant : 1.81*10^4 N/m
  5. mass : 1.045*10^-8 Kg

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Vdc is applied, so that we can get a continuous vibrations of the membrane. Amplitude of vibration is same as the amplitude of Vac when there is no damping. i want to calculate the amplitude when damping(air and support) is included

I want to introduce damping into my design. Im not sure of the calculation. How can i calculate the following

  1. Damping coefficient (considering the system is surrounded by air)
  2. damping ratio
  3. Final amplitude with damping
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Damping can conveniently be introduced in the equation of motion. See http://en.wikipedia.org/wiki/Damped_harmonic_oscillator#Damped_harmonic_oscillator

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  • $\begingroup$ Thank you very much. But is there any way i can quantify damping ratio or damping coefficient from the data given above? $\endgroup$
    – user39910
    Commented Feb 4, 2014 at 15:09
  • $\begingroup$ Is the damping caused by the friction with the surrounding air? It seems it is not included in the parameters you give. Secondly, if there is no driving force the final amplitude will be zero. $\endgroup$
    – Urgje
    Commented Feb 5, 2014 at 10:12
  • $\begingroup$ Im sorry, The system is driven by a 20Vp-p signal. I want to include air and support damping. I have read that Air damping is the most,so im considering that as the major influencing unit $\endgroup$
    – user39910
    Commented Feb 5, 2014 at 14:19

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