## modal damping

## modal damping

(OP)

Hello,

Can'I using a modal analysis determine the effect of friction on the modal damping value of a structure?

or I must apply a sinusoidal force and guettig the the damping value correspending to the modal frequency.

thx

Can'I using a modal analysis determine the effect of friction on the modal damping value of a structure?

or I must apply a sinusoidal force and guettig the the damping value correspending to the modal frequency.

thx

## RE: modal damping

Cheers

Greg Locock

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## RE: modal damping

So you need a formula between the two kind of damping...

Et voila!

ξ

_{friction}=(2η/π)^{2}(1-ω^{2}/ω_{0}^{2})^{2}/(ω^{2}/ω_{0}^{2}[ω^{4}/ω_{0}^{4}-(4η/π)^{2}])## RE: modal damping

eta is the modal damping?? can you submit please the document or the reference for this equation?

Cheers,

## RE: modal damping

## RE: modal damping

but in this book i didn't found this equation ξfriction

and the chapter 30 is about VIBRATION OF STRUCTURES INDUCED BY FLUID FLOW

## RE: modal damping

The chapter 30 is "Theory of vibration isolation" and the equation is in the section "Rigidly connected coulomb damper"