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Rayleigh damping
Posted Sep 29, 2013, 10:27 p.m. EDT MEMS & Nanotechnology, MEMS & Piezoelectric Devices, Structural Mechanics Version 4.3a 1 Reply
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Hi everyone
For a
system with a single degree of freedom (a mass-spring-damper system) the equation of
motion with viscous damping ,i want to specify the damping.i want to ask how to specify αdM and
βdK,there is only one equation c=αdM*m+βdK*k,when i know c m k,how to specify α and β?
thanks all
For a
system with a single degree of freedom (a mass-spring-damper system) the equation of
motion with viscous damping ,i want to specify the damping.i want to ask how to specify αdM and
βdK,there is only one equation c=αdM*m+βdK*k,when i know c m k,how to specify α and β?
thanks all
1 Reply Last Post Sep 30, 2013, 8:41 a.m. EDT
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Posted:
1 decade ago
Hi Li,
Check out the COMSOL documentation under " COMSOL Multiphysics > Structural Mechanics > Theory of Solid Mechanics” for a description of Rayleigh damping. That page shows how to specify alpha and beta if you know the relative damping at two frequencies f1 and f2. Important to check what damping characteristics are obtained at frequencies other than f1 and f2, especially those outside this frequency range. Basically, alpha dampens low frequency response and beta dampens high frequency response.
Nagi Elabbasi
Veryst Engineering
Check out the COMSOL documentation under " COMSOL Multiphysics > Structural Mechanics > Theory of Solid Mechanics” for a description of Rayleigh damping. That page shows how to specify alpha and beta if you know the relative damping at two frequencies f1 and f2. Important to check what damping characteristics are obtained at frequencies other than f1 and f2, especially those outside this frequency range. Basically, alpha dampens low frequency response and beta dampens high frequency response.
Nagi Elabbasi
Veryst Engineering