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2DOF spring-mass free vibrations

2DOF spring-mass free vibrations

2DOF spring-mass free vibrations

(OP)
hi to all

i am looking for a simple program that makes linear dynamic analysis of spring-mass systems with 2DOF or more, under free vibrations


any suggestion?

RE: 2DOF spring-mass free vibrations

Most texts on structural dynamics have developed the differential equation for such a model and condiditions.  Thus I recommend that you grab a text on the subject and with a little work in MathCad, Matlab, Excel, etc you can use linear piece-wise interpolation integration to determine the velocity and displacement responses.

Some texts that are useful are

Structural Dynamics by Clough and Penzien
Structural Dynamics by Craig
Dynamics of Structures by Chopra

Regards,
Qshake

Eng-Tips Forums:Real Solutions for Real Problems Really Quick.

RE: 2DOF spring-mass free vibrations

(OP)
thanks qshake,
that's what i am doing actually, i am using a worksheet (mathcad) for calculating free vibrations of a 2dof system, and since i don't like my results i would check something else

greg thanks for the link
http://www.explorelearning.com/index.cfm?method=cResource.dspView&ResourceID=21

but it's for external actions only and allows only K1=K3, i'd need something even easier, just initial displacement conditions

RE: 2DOF spring-mass free vibrations

Well, why not post your working? or if you don't want to do that, results for the obvious test cases.

Are the errors in the predicted resonant frequencies (for which formualae are easily available) or in the amplitude of response?



Cheers

Greg Locock

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