Viscoelastic Models: Analyzing Relaxation & Creep Data

[La82]

Hi everyone,

So I have a set of relaxation data and creep data for a solid polymer that I want to analyse. In the relaxation I use the Prony series derived from the generalized maxwell equation (incl a spring) and get a very nice fit. My question is if I should use the same to model the creep? Or should I use the generalized Kelvin Voigt?

I have applied the prony series to the creep data and can get a good fit, but I am a bit confused as to the validity of using this model on creep data.

Hope someone can help me with this,

Lonnie

 

[Chestermiller]

The constitutive model is supposed to be independent of the specific deformation. I assume you are using a linear model valid for small deformations. Make sure that the deformations are small. The relaxation data is in shear? Any DMA shear data? That should help test the model to.

Getting back to your original question, if the time scales for the deformations are the same and the deformations are small, then the model fit to the relaxation data should also apply to the creep data.