I recently tried fitting several material models for a cable sheath model made from a PVC-P material with MCalibration. I tried to fit a TNM and a BB-model, because I wasn't sure which one fits the model better. I basically only want to map the strains and stresses as precisely as possible while I'm not really interested in the time dependent behaviour of the material.
I have uniaxial tension and compression experimental data - unfortunately only for one strain rate - done according to your article about smart mechanical testing of polymers (cyclic tests option 1).
According to MCalibration I get a resonable good fit with both material models (fitness between 5-8%) but when I export the model to Ansys and simulate a tensile test the results are way off: The stresses I get are around 20 times lower than the experimental data. (see figure below)
Now I started altering the parameters manually until I got something which at least remotely resembled my experimental data, but I think there should be a better way. I feel like I missed something.
What's causing the deviation between experimental data and simulation results?
Should I perform the experiments with a different strain rate again?