Obtaining viscoelastic parameters from experimental data

[turbulence_decay]

Dear Jorgen,

I conducted tensile tests of PTFE material with increasing load speed for each specimen. In this manner I have obtained results that point out to viscoelastic material behavior. Is there a way to extract viscoelastic parameters out of these tests?

Thank you

[Jorgen]

Yes, you can extracted material parameters for both a linear viscoelastic material model, or a non-linear viscoelasticity model (such as the DNF model).

-Jorgen

[turbulence_decay]

Dear Jorgen,

Can you describe me the way to do this, or send me some references on this topic?

[Jorgen]

It is not the most common way to find the linear viscoelastic material parameters. But it is a perfectly valid approach to use stress-strain curves at different strain rates to determine the required hyperelastic and Prony series numbers. The idea is to find the material parameters that best fit the experimental data.

I use this approach for both linear and nonlinear viscoelastic models.

-Jorgen

[frangibolt]

Dear Jorgen,
I have a similar problem. I conducted tensile and compressive tests increasing the strain rate. I would model this material with a non-linear viscoelastic model, but I can't understand how to obtain the parameters from the sperimental data.
Could you explain briefly (or link ) the correct manner to obtain the charateristic parameters?
Thank you very much!!