POLYFLOW - Use of Polymat to fit a visco-elastic equation in the absence of G', G" data
Is it possible for POLYMAT to identiry the parameters of a viscoelastic model without the G' and G" data, by using the viscosity and transient extension data curves only? It seems that POLYMAT does not want to perform the fit without G' and G'' data and issues a warning. Is there a way to get around this?
This is a somewhat unusual situation, but we understand that acquiring oscillatory data is not allways feasible for all materials. The following workaround is suggested:
o Create dummy files for G' and G" properties and read them into POLYMAT.
o Set the weight of these curves to be very small, like 1.e-12, so that POLYMAT effectively does not use them in curve fitting.
o Fix the relaxation time to an appropriate value. Since we are using dummy G' and G", it appears reasonnable that the value of the relaxation time will have to be supplied to the program.
o Do the curve fitting and get other parameters.