Damping in rubber in Finite Element analysis

[stawrogin]

Hi

I have to model rubber in a direct time integration analysis in a wide frequency range (10 to 1000 Hz) where the internal material damping of the rubber at high frequencies should be modelled as well. I only have one tan (delta) value for the highest frequency. I would prefer to use the Rayleigh damping to estimate these damping effects in the structure than setting up a visco-elastic material model. However I suppose in principle it should work, I’m not sure if this correct and which effects are neglected by the use of the Rayleigh damping instead of a visco-elastic material model. Has anybody experience with such problems or can anybody give some references how modelled these damping effects?

Thanks in advance

stawrogin

 

[ParaDoc]

...see also my answer under "Finite Element Analysis Engineering"

...by the way I forgot to mention there that in case of having the "phase-lag" angle only at a given frequency and not for an relevant range ( ) it would be hard to estimate appropriately, because the dependency of the "phase-lag" on frequency is highly material dependent when rubber is considered.

Just to mention, there is an easy and affordable way to get a suitable characterization of the damping properties of a given rubber grade by using appropriate DMA-measurements and evaluation procedures. This results in a more fully picture of damping behaviour (then given by a set of viscoelastic parameters ==> Prony Series)!