Hello All!
Im studying the rate sensitive behaviour of hyperelastic polymeric materials such as Polyurethane and Polyurea. As such I have planned some uniaxial tensile tests (at high strain rates-my focus)
My question is, whether it is possible to adequately calibrate a constitutive model (e.g. Mooney Rivlin 5 or 9) using this data alone. Since Im considering high strain rates (>1000 /s) are equibiaxial and planar tests possible to do?
Please help.
Thanks,
Dakshitha
It is not a good idea to calibrate a higher order Mooney-Rivlin model using only uniaxial data. You have a few different choices:
[LIST]
[*]Use a I1-based hyperelastic model (e.g. Arruda-Boyce Eight-Chain) that can be calibrated using only uniaxial data.
[*]Perform additional high rate tests. As an example, we often perform tension, compression, shear, and biaxial loading at high rates.
[*]Perform the multiaxial loading experiments at lower strain rates, and then calibrate a suitable viscoelastic / viscoplastic material model to the combination of all low and high rate tests.
[/LIST] -Jorgen