Define the Rate-Dependent Material Model

Define a hyperelastic-viscoelastic material model with neo-Hookean hyperelasticity and Yeoh viscoelasticity.

The Material Calibration app typically uses elastic models or hyperelastic models applied to an N-term Prony Series to capture rate-dependent behavior.

In this example, a Yeoh viscoelastic model applied to a Prony series captures the material behavior accurately.

  1. From the top of the Calibration Setup panel, click Material Model .
  2. Name the material model ButylRubber RateDepYeoh.
  3. From the execution mode list, select Numerical Mode .
    The dialog box updates the list to display the material models that you can define in numerical mode.
  4. Click to expand the tree of supported material behaviors, and select Hyperelastic-Viscoelastic.
  5. Click OK.
    The app adds Hyperelastic and Viscoelastic parameters to the Calibration Setup panel.
  6. From the Hyperelastic options, set the Potential to Yeoh.
    The app populates the Material model section of the Calibration Setup panel with initial parameters for an isotropic Yeoh model and with initial parameters for an N-term Prony series.
  7. Set the Time scale to Long term.
  8. From the Viscoelastic options, set N to 5 and select Reformulation.

    The test data includes five uniaxial tests with different strain rates, so a 5-term Prony Series is required.

    For each parameter, the app provides an initial value. In addition, the app computes the initial responses based on these values and plots a response curve on the same plot as the test data. In the image below, the initial response curves are colored green and the legend has been moved to the right of the curves.