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*HYPERFOAM
Specify elastic properties for a hyperelastic foam.

This option is used to define material constants for a general elastomeric foam. This material is distinct from the regular hyperelastic materials in that it is highly compressible.

Products: Abaqus/Standard  Abaqus/Explicit  Abaqus/CAE  

Type: Model data

Level: Model  

Abaqus/CAE: Property module

References:

Optional parameters:

MODULI

This parameter is applicable only when the *HYPERFOAM option is used in conjunction with the *VISCOELASTIC option.

Set MODULI=INSTANTANEOUS to indicate that the hyperfoam material constants define the instantaneous behavior. This parameter value is not available for frequency domain viscoelasticity in an Abaqus/Standard analysis.

Set MODULI=LONG TERM (default) to indicate that the hyperfoam material constants define the long-term behavior.

N

Set this parameter equal to the order of the strain energy potential. The maximum value is N=6. The default is N=1.

POISSON

Set this parameter equal to the effective Poisson's ratio, , of the material. This parameter is valid only when the TEST DATA INPUT parameter is specified.

If this parameter is included, it is assumed that for all i and that lateral strain test data and volumetric test data are not required. If this parameter is omitted, the are calculated from lateral strain data and/or volumetric test data.

TEST DATA INPUT

Include this parameter if the , the , and the material constants are to be computed by Abaqus from data taken from simple tests on a material specimen. If this parameter is omitted, , , and must be given directly on the data lines.

To define elastomeric foam behavior by giving test data: 

No data lines are used with this option when the TEST DATA INPUT parameter is specified. The data are given instead under the *BIAXIAL TEST DATA, the *PLANAR TEST DATA, the *SIMPLE SHEAR TEST DATA, the *UNIAXIAL TEST DATA, and the *VOLUMETRIC TEST DATA options.

Data lines to define the elastic properties directly: 

First line if N=1:

  1. .

  2. .

  3. .

  4. Temperature.

Repeat this data line as often as necessary to define the material constants as a function of temperature.

First line if N=2:

  1. .

  2. .

  3. .

  4. .

  5. .

  6. .

  7. Temperature.

Repeat this data line as often as necessary to define the material constants as a function of temperature.

First line if N=3:

  1. .

  2. .

  3. .

  4. .

  5. .

  6. .

  7. .

  8. .

Second line if N=3:

  1. .

  2. Temperature.

Repeat this pair of data lines as often as necessary to define the material constants as a function of temperature.

Data lines for higher values of N (up to 6):

  1. The data lines for higher values of N follow the same pattern. First, give the and for i from 1 to N. Then, give the N . Finally, give the temperature. Exactly eight data values should be given on each line.