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Eigen frequency

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respected sir

i want to know about following


1) what do mean by eigen frequency ?

2) why eigen frequencies are imaginary?

3) and how to calculate quality factor?

waiting for reply sir





1 Reply Last Post 6 mag 2011, 08:04 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 6 mag 2011, 08:04 GMT-4
Hi

check the doc, first of all: in a few words, an eigenfrequency is the frequency of the fundamental modes of vibrations of a structure (or another non solid model) obeying a vibration compatible PDE law (thermal or diffusion cannot generate modes in the same sense)

When an eigenfrequency is complex, it means that you have damping and dephasing of the mode shape/response. the you need to plot the real() and arg() part or abs() and arg() (arg() = atan2(imag()/real()) part)

--
Good luck
Ivar
Hi check the doc, first of all: in a few words, an eigenfrequency is the frequency of the fundamental modes of vibrations of a structure (or another non solid model) obeying a vibration compatible PDE law (thermal or diffusion cannot generate modes in the same sense) When an eigenfrequency is complex, it means that you have damping and dephasing of the mode shape/response. the you need to plot the real() and arg() part or abs() and arg() (arg() = atan2(imag()/real()) part) -- Good luck Ivar

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