Critical Frequency Calculator

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Density (kg/m³):

Module de Young (MPa):

Thickness (m):

Poisson Modulus:

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The Critical Frequency appears when the bending wavelength is equal to the acoustic wavelength (or the celerity of the bending wave is equal to the sound celerity) :
$$ f_c = \frac{c_0^2}{2\sqrt{\frac{\rho_s}{B_p}}} = \frac{c_0^3}{\sqrt{\pi}} \sqrt{\frac{3\rho_s(1-\nu^2)}{Eh^3}} $$ with :

$ \rho_s $ the mass per square meter (m²)
$ E $ the Young Modulus (Pa)
$ \nu $ the Poisson Modulus
$ h $ the thickness (m)
$ c_0 $ the sound celerity (m/s)

References : Sound Insulation - Carl Hopkins