I am new user of MCalibration and to polymer material modelling. Currently I would like to reproduce some results using already calibrated PRF models in the company. Such models were calibrated using an older MCalibration version 5.xx but company's version is now 6.6.
I am always facing the error below despite the time integration increment size I choose: "Error: dt < dtmin"
Current time step increment setup is initial: 0.01s; Minimum: 1e-10s and Maximum :100s. Time span is 10E5 s and it is related to a relaxation test. Solver is MCalibration. Issue still persists if I use whether “Follow the same time increments as specified in the experimental data file” or “Specify the minimum number of time increments” options.
The only way I found to have some rough predicted data is to change "D1" parameter to zero. In release 5.xx MCalibration asked for "kappa" among PRF-3YP parameters but I realize it already converts kappa to D1 when I open the old version file in the new 6.6 release. Since D1 is related to material bulk modulus I can't just change it blindly so as to have a result.
This time integration increment issue is puzzling me taking into account that model used to work fine in earlier version. Does anybody have any piece of advice to share with?