10.3 Stress_Model: Hyperelasticity Model

HYPERELASTIC

Material_name = HYPERELASTIC

Material_set_number = mset , etc...

The following hyperelastic stored energy function with uncoupled volumetric and deviatoric parts is employed:

where

It follows that the Kirchhoff stress is given by:

Note Variable Name Type Default Description

• Keywords Read Method

Material_set_number integer [1] Material set number Numat

Hyperelastic_case integer [0] Hyperelastic free energy function:

Mass_density real [0.0] Mass density

Shear_modulus real [0.0] Shear modulus G

Bulk_modulus real [0.0] Bulk modulus B

(1) Solid_mass_density real [0.0] Mass density (Solid Phase)

(1) Fluid_mass_density real [0.0] Mass density (Fluid Phase)

(1) Fluid_bulk_modulus real [0.0] Fluid bulk modulus

(1) Porosity real [0.0] Porosity

(2) Initial_stress

initial_stress_11 real [0.0] Component 11 ()

initial_stress_22 real [0.0] Component 22 ()

(cont’d)

^(cont'd)

Note Variable Name Type Default Description

initial_stress_33 real [0.0] Component 33 ()

initial_stress_33 real [0.0] Component 33 ()

initial_stress_12 real [0.0] Component 12 ()

initial_stress_12 real [0.0] Component 12 ()

initial_stress_23 real [0.0] Component 23 ()

initial_stress_31 real [0.0] Component 31 ()

• List Read Method

Material data must follow in the form:

< m, IHyper(m), G(m), B(m), (m), (m), (m), (m), Pf(m) >

< (Stres(i, m), i = 1, 6) >

< terminate with a blank record >.

Notes/

(1) Only applicable to porous media models.

(2) Tensile stresses are positive.