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Is It Possible To Keep The Eigen Frequencies And Eigen Modes Of A Flexible Body?

04/03/2017 4:37 AM

is it possible to represent a flexible body by a multiple of rigide bodies (<10 bodies), this rigide bodies are attached between them by springs and dumpers so they can behave exacly like the flexible body once they are excited at the eigen frequencies of the flexible body. i know some will say try to mesh it and use FEA, but i don't have a good FEA soft, so i'm trying to represente the meshed body in a non Finite element software.

thanks

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#1

Re: Is It Possible To Keep The Eigen Frequencies And Eigen Modes Of A Flexible Body

04/03/2017 9:49 AM

Sure it's possible, but you may end up implementing something akin to the physics guts of an FEA program. Whilst that would be enormously educational, if you've time constraints your time may be better spent trying to secure the use of an FEA program. Is this a school project?

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#2
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Re: Is It Possible To Keep The Eigen Frequencies And Eigen Modes Of A Flexible Body

04/03/2017 10:51 AM

It's for an internship project, i wish to use a good FEA software but the company is afraid of investing in somthing big like Ansys, so if you have any open source software i'm all listning.:-)

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#3
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Re: Is It Possible To Keep The Eigen Frequencies And Eigen Modes Of A Flexible Body

04/03/2017 11:08 AM

Take a look at Code Aster. Open source. Right up there with Ansys and Comsol Multiphysics.

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#5
In reply to #2

Re: Is It Possible To Keep The Eigen Frequencies And Eigen Modes Of A Flexible Body

04/03/2017 11:28 AM

Try FreeCAD. FEM is available using calculix solver.

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#4

Re: Is It Possible To Keep The Eigen Frequencies And Eigen Modes Of A Flexible Body

04/03/2017 11:18 AM

Use wave equation on a membrane or a 3d solid. Analyse using Finite Difference Method script in MATLAB or in phyton.

See equation 3. You can adjust speed of propagation for the stiffness, I guess.

It's just like a wave of some sort.

Don't tell me this is homework?

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#6
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Re: Is It Possible To Keep The Eigen Frequencies And Eigen Modes Of A Flexible Body

04/03/2017 7:45 PM

Gutmonarch, may I ask what country you are from? Just out of curiosity, I am pretty sure its not the U.S. If I had to guess, I would guess the Philippines, this is not a dig, I just want to know.

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#7
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Re: Is It Possible To Keep The Eigen Frequencies And Eigen Modes Of A Flexible Body

04/04/2017 1:45 AM

Yep, don't hide black coal in your pockets for me, alright?

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#8
In reply to #7

Re: Is It Possible To Keep The Eigen Frequencies And Eigen Modes Of A Flexible Body

04/05/2017 6:17 PM

Why would I hide black coal in my pockets for you?

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