Available material models

The following Ansys Mechanical models are available. For more information about these models, see section 4 of the Mechanical APDL Theory Reference.

Model Order Required loading type and data
Arruda-Boyce N/A

One or more of:

  • Uniaxial (Tensile response)
  • Biaxial (Tensile response)
  • Pure shear (Shear response)
  • Simple shear‡ (Shear response and Normal Stress vs Strain)
  • Volumetric‡ (Pressure vs Volume ratio)
Bergstrom-Boyce§ N/A

One or more of:

  • Uniaxial (Tensile response and Stress vs Time)
  • Biaxial (Tensile response and Stress vs Time)
  • Pure shear (Shear response and Stress vs Time)
  • Simple shear‡ (Shear response, Normal Stress vs Strain, and Stress vs Time)
  • Volumetric‡ (Pressure vs Volume ratio and Pressure vs Time)

Bilinear Isotropic

Hardening

 N/A Uniaxial only, True Stress vs True Strain. All strain histories allowed: monotonic loading/unloading, cyclic loading etc.
Blatz-Ko (Blatz-Ko Foam) N/A

One or more of:

  • Uniaxial (Tensile response and Lateral strain vs Strain)
  • Biaxial (Tensile response and Lateral strain vs Strain)
  • Pure shear (Shear response and Lateral strain vs Strain)
  • Simple shear‡ (Shear response and Normal Stress vs Strain)
  • Volumetric‡ (Pressure vs Volume ratio)

Chaboche Kinematic

Hardening

 1-5 Uniaxial only, True Stress vs True Strain. All strain histories allowed: monotonic loading/unloading, cyclic loading etc.
Extended Tube N/A

One or more of:

  • Uniaxial (Tensile response)
  • Biaxial (Tensile response)
  • Pure shear (Shear response)
  • Simple shear‡ (Shear response and Normal Stress vs Strain)
  • Volumetric‡ (Pressure vs Volume ratio)
Gent N/A

One or more of:

  • Uniaxial (Tensile response)
  • Biaxial (Tensile response)
  • Pure shear (Shear response)
  • Simple shear‡ (Shear response and Normal Stress vs Strain)
  • Volumetric‡ (Pressure vs Volume ratio)
Mooney-Rivlin 2, 3, 5, 9

One or more of:

  • Uniaxial (Tensile response)
  • Biaxial (Tensile response)
  • Pure shear (Shear response)
  • Simple shear‡ (Shear response and Normal Stress vs Strain)
  • Volumetric‡ (Pressure vs Volume ratio)
Mullins Effect* N/A

As for base model, plus:

  • Strain vs time for Uniaxial, Biaxial, Pure Shear and Simple Shear tests
  • Pressure vs time for Volumetric tests
Neo-Hookean N/A

One or more of:

  • Uniaxial (Tensile response)
  • Biaxial (Tensile response)
  • Pure shear (Shear response)
  • Simple shear‡ (Shear response and Normal Stress vs Strain)
  • Volumetric‡ (Pressure vs Volume ratio)

Nonlinear Isotropic

Hardening Power Law

 N/A Uniaxial only, True Stress vs True Strain. All strain histories allowed: monotonic loading/unloading, cyclic loading etc.

Nonlinear Isotropic

Hardening Voce Law

 N/A Uniaxial only, True Stress vs True Strain. All strain histories allowed: monotonic loading/unloading, cyclic loading etc.
Ogden (Ogden Potential) 1-5†

One or more of:

  • Uniaxial (Tensile response)
  • Biaxial (Tensile response)
  • Pure shear (Shear response)
  • Simple shear‡ (Shear response and Normal Stress vs Strain)
  • Volumetric‡ (Pressure vs Volume ratio)
Ogden Hyperfoam (Ogden Compressible Foam) 1-5†

One or more of:

  • Uniaxial (Tensile response and Lateral strain vs Strain)
  • Biaxial (Tensile response and Lateral strain vs Strain)
  • Pure shear (Shear response and Lateral strain vs Strain)
  • Simple shear‡ (Shear response and Normal Stress vs Strain)
  • Volumetric‡ (Pressure vs Volume ratio)
Polynomial Form 1-5

One or more of:

  • Uniaxial (Tensile response)
  • Biaxial (Tensile response)
  • Pure shear (Shear response)
  • Simple shear‡ (Shear response and Normal Stress vs Strain)
  • Volumetric‡ (Pressure vs Volume ratio)
Prony Series Shear 1-5
  • Shear decay (Shear modulus vs Time OR Shear storage modulus vs Frequency and loss modulus vs Frequency)
Prony Series Bulk 1-5
  • Bulk decay (Bulk modulus vs Time OR Bulk storage modulus vs Frequency and loss modulus vs Frequency)
Prony Series Shear & Bulk 1-5
  • Shear decay (Shear modulus vs Time OR Shear storage modulus vs Frequency and loss modulus vs Frequency) and Bulk decay (Bulk modulus vs Time OR Bulk storage modulus vs Frequency and loss modulus vs Frequency)
Three Network Model (TNM)** N/A

One or more of:

  • Uniaxial (Tensile response and Stress vs Time)
  • Biaxial (Tensile response and Stress vs Time)
  • Pure shear (Shear response and Stress vs Time)
  • Simple shear‡ (Shear response, Normal Stress vs Strain and Stress vs Time)
  • Volumetric‡ (Pressure vs Volume ratio and Pressure vs Time)
Yeoh 1-5

One or more of:

  • Uniaxial (Tensile response)
  • Biaxial (Tensile response)
  • Pure shear (Shear response)
  • Simple shear‡ (Shear response and Normal Stress vs Strain)
  • Volumetric‡ (Pressure vs Volume ratio)

*Modifier for damage modeling.

**For viscoplastic materials (for example, polymers).

§Phenomenological basis, for elastomers or biomaterials.

†Note that Ansys Workbench currently supports orders 1-3 only.

‡Can only be modeled if Uniaxial, Biaxial or Pure Shear data is also selected.

Supported model combinations

Material model parameters can be fitted simultaneously for several combinations of hyperelastic and viscoelastic models. A single curve must be provided for a given test type, and it should include both the loading and relaxation portions of the response.

Data requirements for the individual models in these combinations follow from the list above. A single curve must be provided for a given test type, and it should include both the loading and relaxation portions of the response.

Supported model combinations include:
  • Arruda-Boyce with Prony Shear (orders 1 to 5), and Arruda-Boyce with Prony Shear & Bulk (orders 1 to 5)
  • Extended Tube with Prony Shear (orders 1 to 5), and Extended Tube with Prony Shear & Bulk (orders 1 to 5)
  • Gent with Prony Shear (orders 1 to 5), and Gent with Prony Shear & Bulk (orders 1 to 5)
  • Mooney-Rivlin (2-, 3-, 5-, 9-Parameter) with Prony Shear (orders 1 to 5), and Mooney-Rivlin (2-, 3-, 5-, 9-Parameter) with Prony Shear & Bulk (orders 1 to 5)
  • Neo-Hookean with Prony Shear (orders 1 to 5), and Neo-Hookean with Prony Shear & Bulk (orders 1 to 5)
  • Ogden (orders 1 to 5) with Prony Shear (orders 1 to 5), and Ogden (orders 1 to 5) with Prony Shear & Bulk (orders 1 to 5)
  • Polynomial Form (orders 1 to 5) with Prony Shear (orders 1 to 5), and Polynomial Form (orders 1 to 5) with Prony Shear & Bulk (orders 1 to 5)
  • Yeoh (orders 1 to 5) with Prony Shear (orders 1 to 5), and Yeoh (orders 1 to 5) with Prony Shear & Bulk (orders 1 to 5)
These models can be combined with Mullins Effect for continuum damage where relevant test data is available.
Material Calibration can now be performed for the following rate-independent plasticity models:
  • Isotropic Elasticity + Isotropic Hardening, with 3 choices of hardening laws:
    • Bilinear Hardening
    • Nonlinear Hardening, Power Law
    • Nonlinear Hardening, Voce Law
  • Isotropic Elasticity + Kinematic Hardening, with Chaboche type hardening of orders 1 to 5