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vibration by a shaker
Posted 23.05.2014, 01:41 GMT-4 Acoustics & Vibrations Version 4.3 2 Replies
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hi. i'm new to the comsol. please help me to determine the study for vibration by a shaker. here the model. i want to determine the natural frequency for this model. help me please.
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2 Replies Last Post 23.05.2014, 10:27 GMT-4
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Posted:
1 decade ago
Hi
The first information you get it from a "free-free" or a "fixed" eigenfrequency analysis of your device (in structural Physics).
You need to decide how you attach your device and to what, normally one considers an infinitely rigid base structure to which one attach any device with some representative attachment means.
With thee modes of the eigenfrequency analysis (that you might select by importance w.r.t. their mass participation ratio, but be aware that COMSOL still do not provide rotational mass (inertia) participation ratios, strangely, all other engineering FEM software do ...;), you can then decide for a stepping range for a frequency sweep analysis (typically 5-10 steps between modes and some 10 steps directly around any relevant eigenfrequency modes, and load your device with i.e. a "body load" of given amplitude, or of a given power spectral density deduced amplitude you define in a function.
Or you attach the device to a "rigid big mass" and apply a frequency dependent acceleration to the base
--
Good luck
Ivar
The first information you get it from a "free-free" or a "fixed" eigenfrequency analysis of your device (in structural Physics).
You need to decide how you attach your device and to what, normally one considers an infinitely rigid base structure to which one attach any device with some representative attachment means.
With thee modes of the eigenfrequency analysis (that you might select by importance w.r.t. their mass participation ratio, but be aware that COMSOL still do not provide rotational mass (inertia) participation ratios, strangely, all other engineering FEM software do ...;), you can then decide for a stepping range for a frequency sweep analysis (typically 5-10 steps between modes and some 10 steps directly around any relevant eigenfrequency modes, and load your device with i.e. a "body load" of given amplitude, or of a given power spectral density deduced amplitude you define in a function.
Or you attach the device to a "rigid big mass" and apply a frequency dependent acceleration to the base
--
Good luck
Ivar
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Posted:
1 decade ago
where i can search for the frequency sweep analysis?