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Inertia force with an eigenmode-shaped acceleration distribution

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Hi all, Is it possibile to insert an inertia force (maybe using the gravity load type) with an acceleration distribution taken from an eigenmode of an eigenfrequency analysis?

The problem is to give a value of the acceleration which is not constant but variable in space (x,y,z). The variation should be equal to a displacement distribution of an eigenmode.

In other words is it possibile to obtain the analytical displacement function of an eigenmode? (knownig that it represents diplacements ratios and not absolute values).

Hope to be sufficiently clear Thank you in advanced, Best regards


2 Replies Last Post 28 oct. 2019, 11:02 UTC−4
Henrik Sönnerlind COMSOL Employee

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Posted: 5 years ago 24 oct. 2019, 11:17 UTC−4

Hi,

You can do that using the withsol() operator. In the Gravity node, type something like

withsol('sol1',w,setind(lambda,1))

Here 'sol1' is the tag for your eigenfrequnecy solution. '1' means the first eigenmode.

Regards,
Henrik

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Henrik Sönnerlind
COMSOL
Hi, You can do that using the withsol() operator. In the Gravity node, type something like withsol('sol1',w,setind(lambda,1)) Here 'sol1' is the tag for your eigenfrequnecy solution. '1' means the first eigenmode. Regards, Henrik

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Posted: 5 years ago 28 oct. 2019, 11:02 UTC−4

Hi Henrik, Thank you very much, it works. Best regards Elia

Hi Henrik, Thank you very much, it works. Best regards Elia

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