COMSOL Forums: Vibration of a cantilever beam

Re: Vibration of a cantilever beam

Fri, 18 Jan 2013 05:52:12 +0000

Hi

I would propose harmonic development (frequency sweep swith a constant force amplitude (or a frequency dependet if you want to scan a PSD (power spectral density) distribution)

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Good luck
Ivar

Re: Vibration of a cantilever beam

Thu, 17 Jan 2013 20:22:06 +0000

Hi,
Thanks for your response.
I have indeed applied body load (i.e. g*acceleration). But my question is to get appropiate solution, what kind of study should I do? Should I apply the body load in the form of a sinusoid and do time dependent analysis with t defined for more than one time period (1/first eigen freq)? Is that correct or any other kind of simulation setup is needed?

Thanks in advance.

Re: Vibration of a cantilever beam

Thu, 17 Jan 2013 19:43:33 +0000

Hi

the vibration load aspect is not trivial, you can either define a gravity = body force rho*a (a=acceleration) applying onto your model, with one boundary fixed, or add a "large Mass" object that can slide onto which you apply a force of given F=M*a with a the acceleration.

But the transfer functions are not exactly the same. Check the Forum, it has been discussed a few times
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Good luck
Ivar

Vibration of a cantilever beam

Thu, 17 Jan 2013 10:57:13 +0000

Hi,
I am trying to model a beam oscillating under external vibration condition.
I have kept one end of the beam fixed. I have tried applying different kind of boundary conditions to solve the problem.
1. applied accelaration (10m/s2) on the fixed end and did the freq domain analysis.
2. applied accelaration (10m/s2) on the entire structure and did the freq domain analysis.

but i did not get the expected displacement of the beam.

can anyone suggest what would be the appropiate boundary conditions and analysis method for such case?