What does tan-delta curve measure? 1

[qww]

Hi all,

I've just been handed a data summary from a DMTA test. I'm trying to find help interpreting a "tan-delta" curve. Specifically, what is it, what is it used for, and how does it relate to all of the other polyeric properties I am familiar with?

Thanks in advance for your help!
Tony

 

[karlberg]

When materials which are not perfectly elastic are stressed cyclically, strain is not
in phase with the stress applied. Phase difference observed is delta. In each cycle
of loading, there is energy dissipation in such materials. Tan delta is a measure of
damping, i.e., energy dissipation in such materials in each cycle of loading.

 

[keepuh]

Tan Delta is the viscous modulus divided by the elastic modulus.

 

[zzl]

The Tan-delta normally using to quantify the dissipation of the viscoelastic material. For an ideal elastic solid, Tan-delta=0 degree ; for a pure viscous fluid, Tan-delta=180 degree; and for a viscoelastic material 180>Tan-delta>0.

 

[msmith]

zzl,

I believe that for a purely viscous fluid Tan-delta = 90°

 

[zzl]

msmith,

You're right, It was my mistake.