Define hyperelastic materials

This topic covers the procedure for adding hyperelastic materials for use in simulation studies. You may want to use a hyperelastic material for nonlinear simulations such as

  1. Click physical material icon (Simulation workspace > Setup tab > Materials panel > Manage Physical Materials) to open the Material Browser.

  2. Choose an existing material, perhaps from the Plastic branch of the Fusion Material Library, to use as a starting template for your hyperelastic material. Click the add material to favorites and edit icon arrow and pencil icon that appears at the right end of the line to add the material to the Favorites library and display the properties for editing.

  3. Under the Identity tab in the right side of the expanded dialog, define the following properties:

    • Type in a suitable Description for the new material.
    • Since a Hyperelastic option is not available, choose Generic from the Type pull-down list.
    • Optionally, define any other properties under this tab that you want to specify (Comments, Manufacturer, and so on).

  4. Optionally, under the Appearance tab, revise any of the properties you want changed (Color, Reflectance, Translucency, and so on).

  5. Click on the Physical tab.

    The Basic Properties are initially displayed. Only the Density value is relevant for hyperelastic materials within nonlinear simulations. However, the other basic properties are required to also use your hyperelastic materials within linear simulations. In the latter case, the material does not act like a true hyperelastic material but is represented using linear isotropic behavior.

  6. Define the Basic material properties (Young's Modulus, Poisson's Ratio, Density, Thermal Expansion Coefficient, Specific Heat, and so on). Expand the Basic Thermal, Mechanical, and Strength settings groups as needed to access the various input fields.

  7. Activate the Advanced Properties checkbox.

  8. Click the Advanced Properties button, being careful not to click on the checkbox again, which would deactivate the Advanced Properties. The Mooney-Rivlin constant input fields appear.

  9. Define the following three constants:

    1. A01: First of two Distortional Constants related to shear deformation of the material.

    2. A10: Second of two Distortional Constants related to shear deformation of the material.

    3. D1: Constant related to volumetric deformation of the material.

      The D1 field accepts one of the following two inputs:

      • Specify the actual D1 value from material tests.
      • Specify an arbitrary and relatively high D1 value to approximate incompressible behavior. It is recommended that you do not enter a D1 value greater than (A01 + A10) x 103.
      Important: Various testing labs and publications present Mooney-Rivlin data somewhat differently. Be sure to specify constants that are consistent with the Fusion implementation. Refer to Hyperelastic materials theory for the Mooney-Rivlin equation and definitions of the A01, A10, and D1 constants.

      Be sure to use consistent units between material tests, curve-fitting, and the Fusion inputs, or correctly convert between unit systems. The default material units are specified using the Material Unit Display drop-down menu in the Unit and Value Display group of the Preferences dialog. You can also override the default units by typing supported alternative units after the number in the input field (such as psi, GPa, MPa, or dyne). After you enter a constant in alternative units, it is immediately converted to default material units.

  10. Click Apply to save the properties of your new material.

  11. Optionally, perform one of the following two steps:

    • If you have created a Hyperelastic category within the Favorites library, click and drag your new material into the Hyperelastic group. The categories appear in the tree at the left side of the dialog immediately beneath the Favorites heading.

      Note: The material will continue to be listed in the top-level of the Favorites library, but the Category field will now identify it as Hyperelastic. To filter the list to display only hyperelastic materials, select that category from the tree. This filtering technique applies to any other categories you might define for organizational purposes.

    • If you have created a custom user library for hyperelastic materials, right click the material name among the listed materials in the Favorites library. Choose (Add to > Hyperelastic Materials) from the context menu. (Substitute the actual name of your library that appears, if different from the suggested library name).

Once you have created a hyperelastic material definition, you apply it to a simulation in the same manner as for any type of material.

Parent page: Hyperelastic materials