Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

determination of Q factor

Shyamsananth Madhavan

Please login with a confirmed email address before reporting spam

Hi
I just finished tutorial of determination of Q factor of gryoscope.
I am working on Resonant Accelerometers.

In tutorial , u have provided alternate method
Q=?0/2? = abs(imag?/2real?).

I tried this for my accelerometer ... it gave no real part of Eigen Frequency. Only imag part is available. As a result Q factor becomes NaN.
I tried with a cantilever , hard luck Q is NaN.


Can anyone elaborate this method ? I need to find the Q for my accelerometer structure.

Steps I took
Freq response module ---- applied Body load --- In scalar variables change Freq_smps to lambda/2*pi*i ---- solve in eigenfrequency solver under Freq Response Analysis type....


I think my steps are right as per the Tutorials.


Please Help me out...

1 Reply Last Post 18.06.2010, 01:32 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 18.06.2010, 01:32 GMT-4
Hi

I cannot reply directly on your examples, but do not forget that a "Q" factor is directly linked a loss factor, you how have you defined the losses in your model ? Do you have material losses, electric losses, (and numerical losses) these all contribute and should be present and quantified.

Good luck
Ivar
Hi I cannot reply directly on your examples, but do not forget that a "Q" factor is directly linked a loss factor, you how have you defined the losses in your model ? Do you have material losses, electric losses, (and numerical losses) these all contribute and should be present and quantified. Good luck Ivar

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.