Entering material parameters to define an isotropic hyperelastic material

From the menu bar in the Edit Material dialog box, select MechanicalElasticityHyperelastic.
(For information on displaying the Edit Material dialog box, see Creating or editing a material.)
Choose Isotropic as the material type.
Click the arrow to the right of the Strain energy potential field, and select the strain energy potential of your choice.

Arruda-Boyce

The Arruda-Boyce model is also known as the eight-chain model. For more information, see Arruda-Boyce form.

Marlow

For more information, see Marlow form.

Mooney-Rivlin

The Mooney-Rivlin model is equivalent to using the polynomial model with N=1. For more information, see Mooney-Rivlin form.

Neo Hooke

The Neo Hookean model is equivalent to using the reduced polynomial model with N=1. For more information, see Neo-Hookean form.

Ogden

For more information, see Ogden form.

Polynomial

For more information, see Polynomial form.

Reduced Polynomial

The reduced polynomial model is equivalent to using the polynomial model with $C_{i j} = 0$ for $j \neq 0$ . For more information, see Reduced polynomial form.

User-defined

You can define the derivatives of the strain energy potential with respect to the strain invariants in user subroutine UHYPER. This method is valid only for Abaqus/Standard analyses. For more information, see User subroutine specification in Abaqus/Standard.

Van der Waals

The Van der Waals model is also known as the Kilian model. For more information, see Van der Waals form.

Yeoh

The Yeoh model is equivalent to using the reduced polynomial model with N=3. For more information, see Yeoh form.

Unknown

If you define an isotropic hyperelastic material using experimental data, you also have the option of temporarily leaving the particular strain energy potential unspecified. You can use the Evaluate option to identify the optimal strain energy potential for the material data and display the material editor again to complete the material definition; see Evaluating hyperelastic and viscoelastic material behavior, for more information.
Select Coefficients as the Input source. This Input Source option is invalid for the Marlow model or for an unknown strain energy potential.
If you are defining the hyperelastic behavior of a viscoelastic material, click the arrow to the right of the Moduli time scale (for viscoelasticity) field to specify either long-term or instantaneous elastic response.
If you selected User-defined as the strain energy potential, perform the following steps:
- Toggle on Include compressibility to indicate that the material defined by user subroutine UHYPER is compressible. Otherwise, Abaqus assumes the material is incompressible.
- Specify the Number of property values needed as data in user subroutine UHYPER.
If you selected Ogden, Polynomial, or Reduced Polynomial as the strain energy potential, click the arrows to the left of the Strain energy potential order field to select a value.
To define behavior data that depend on temperature, toggle on Use temperature-dependent data.
A column labeled Temp appears in the Data table.
Enter the material properties in the Data table corresponding to the chosen strain energy potential.

Arruda-Boyce

Enter $μ$ , $λ_{m}$ , and D.

Mooney-Rivlin

Enter $C_{10}$ , $C_{01}$ , and $D_{1}$ .

Neo Hooke

Enter $C_{10}$ and $D_{1}$ .

Ogden

Enter $μ_{i}$ , $α_{i}$ , and $D_{i}$ , where i goes from 1 to N and N is the value specified for the Strain energy potential order.

Polynomial

Enter $C_{i j}$ , where $i + j$ goes from 1 to N, and $D_{i}$ , where i goes from 1 to N, and N is the value specified for the Strain energy potential order.

Reduced Polynomial

Enter $C_{i 0}$ and $D_{i}$ , where i goes from 1 to N and N is the value specified for the Strain energy potential order.

Van der Waals

Enter $μ$ , $λ_{m}$ , a, $β$ , and D.

Yeoh

Enter $C_{10}$ , $C_{20}$ , $C_{30}$ , $D_{1}$ , $D_{2}$ , and $D_{3}$ .
If desired, select Hysteresis from the Suboptions menu to define hysteretic behavior. See Defining hysteretic behavior for an isotropic hyperelastic material model” for details.
Click OK to create the material and to close the Edit Material dialog box. Alternatively, you can select another material behavior to define from the menus in the Edit Material dialog box (see Browsing and modifying material behaviors, for more information).