PTFE Seals on ABAQUS

[tanmoy.db]

Hi all,
I'm simulating stress relaxation of a PTFE lip seal using Abaqus. I have developed the model. But i'm having trouble with the material properties. I used the experimental data for PTFE provided by Dr. Jorgen. But every time i use the data with hyperelstic model (Mooney-Rvillin) the data file tells me that "hyperelastic material is unstable".
I have a couple of questions.....\
1) Is that a specific data set that i should be using and which one should it be??
2) What are the material constants C10 and C01 for PTFE to be used with M-R model ?

Thanks in advance.

[Jorgen]

You should be able to use any data set(s) for the material model calibration. MCalibration (http://polymerfem.com/content.php?9-MCalibration)is more powerful than your current calibration program.
I don't have the MR parameters :(

-Jorgen

[tanmoy.db]

Is there any specific reason that ABAQUS is unable to calibrate the data set?

I have e-mailed you my details, requesting access to MCalibration Tool. It would be a major help, if i could get access to it.

Thank You.