Menu

Discussion Forum

New Discussion
Filter

Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.

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.

vibration by a shaker

Posted May 23, 2014, 1:41 a.m. EDT Acoustics & Vibrations Version 4.3 2 Replies

Fatin Nabila Mazlan
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

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.

Attachments:

2 Replies Last Post May 23, 2014, 10:27 a.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago May 23, 2014, 5:00 a.m. EDT
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
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
Fatin Nabila Mazlan
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago May 23, 2014, 10:27 a.m. EDT
where i can search for the frequency sweep analysis?
where i can search for the frequency sweep analysis?

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.

Suggested Content