Convergence

[599]

Hi,
I want to define a viscoelastic material in ABAQUS, but I have faced a problem. In order to define the material I follow these steps:
first I defined a hyperelastic material using uniaxial test data:
stress: 0.265 0.53 1.19 1.85 ... MPa
strain: 0.078 0.124 0.17 0.215
and then I defined a aviscoelastic material using time domain and stress relaxation data>shear test data
relaxation function: 0.67 0.63 0.605 0.59 0.576
time: 60 120 180 240 300 sec
WHEN I evaluated the material, I got this error:
convergence can not be obtained with positive coefficients and sufficient accuracy for viscoelastic shear test data.
would you please help me solve this problem?
Thanks,

[Jorgen]

I have never seen that error message before, and your experimental data points seem OK to me. Typically you should specify more data points than that, though.

Can you double-check that you entered the data correctly. If you cannot get it to work, you can always determine the Prony series yourself, and enter that directly.

-Jorgen