Eigen Mode Shapes and Stiffness 1

[Anbaz]

Hallo Everyone,
I want to understand the relation between eigen mode shapes and stiffness. Suppose the first eigen mode shape of a component at 20Hz is a bending mode and the second eigen mode at 30Hz is a torsional mode. I read that stiffness K is proportional to frequency, f. So according to this relation, does the component has more torsional stiffness than bending stiffness?.
Thanks for your help.

Best Regards
Anbaz

 

[BrianE22]

I don't know much about Eigenvectors but for discrete masses and springs, f is proportional to sqrt(k)

 

[GregLocock]

No, it means that the ratio of bending stiffness to bending 'inertia', is less than the ratio of torsional stiffness to torsional 'inertia', crudely.

Cheers

Greg Locock


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