Neo-Hookean
The Neo-Hookean material model is described in terms of the strain energy potential, W, as follows:
where

and

are material constants.
You can use materials constants to calculate the initial shear modulus as follows:
You can also calculate initial bulk modulus for the material as follows:
When you select
Neo-Hookean material model
to define the hyperelastic material, you must specify values for

and

.
For materials that are nearly incompressible,
Creo Simulate uses incompressibility conditions. If the specified value of

is less than

,
Creo Simulate uses following value of

during analysis:

=

.
where G is the initial shear modulus.
Creo Simulate calculates these constants when you select
Neo-Hookean material model on the
Hyperelastic Material Definition dialog box.