*PLANAR TEST DATA

Used to provide planar test (or pure shear) data (compression and/or tension).

This option is used to provide planar test (or pure shear) data. It can be used only in conjunction with the HYPERELASTIC option, the HYPERFOAM option, and the MULLINS EFFECT option. This type of test does not define the hyperelastic material constants fully; at the least, uniaxial or biaxial test data should also be given.

This page discusses:

Using planar test data to define a hyperelastic material
Using planar test data to define an elastomeric foam
Using planar test data to define the Mullins effect material model

Using planar test data to define a hyperelastic material

Optional parameters

SMOOTH

Include this parameter to apply a smoothing filter to the stress-strain data. If the parameter is omitted, no smoothing is performed.

Set this parameter equal to the number n such that $2 n + 1$ is equal to the total number of data points in the moving window through which a cubic polynomial is fit using the least-squares method. n should be larger than 1. The default is SMOOTH=3.

Optional parameter when the PLANAR TEST DATA option is used in conjunction with the HYPERELASTIC, MARLOW option

DEPENDENCIES: Set this parameter equal to the number of field variable dependencies included in the definition of the test data. If this parameter is omitted, it is assumed that the test data depend only on temperature. See Material Data Definition for more information.

Data lines to specify planar test data for hyperelasticity other than the Marlow model (the nominal strains must be arranged in either ascending or descending order if the SMOOTH parameter is used)

First line

Nominal stress, $T_{S}$ .
Nominal strain in the direction of loading, $ϵ_{S}$ .

Repeat this data line as often as necessary to give the stress-strain data.

Data lines to specify planar test data for the Marlow model (the nominal strains must be arranged in ascending order if the SMOOTH parameter is used)

First line

Nominal stress, $T_{S}$ .
Nominal strain, $ϵ_{S}$ .
Nominal lateral strain, $ϵ_{3}$ . Not needed if the POISSON parameter is specified on the HYPERELASTIC option or if the VOLUMETRIC TEST DATA option is used.
Temperature, $θ$ .
First field variable.
Second field variable.
Etc., up to four field variables.

Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than four)

Fifth field variable.
Etc., up to eight field variables per line.

Repeat this set of data lines as often as necessary to define the test data as a function of temperature and other predefined field variables. Nominal strains and nominal stresses must be given in ascending order.

Using planar test data to define an elastomeric foam

There are no parameters associated with this option.

Data lines to specify planar test data for a hyperfoam

First line

Nominal stress, $T_{L}$ .
Nominal strain in the direction of loading, $ϵ_{P}$ .
Nominal transverse strain, $ϵ_{3}$ . Default is zero. Not needed if the POISSON parameter is specified on the HYPERFOAM option.

Repeat this data line as often as necessary to give the stress-strain data.

Using planar test data to define the Mullins effect material model

There are no parameters associated with this option.

Data lines to specify planar test data for defining the unloading-reloading response of the Mullins effect material model

First line

Nominal stress, $T_{L}$ .
Nominal strain in the direction of loading, $ϵ_{P}$ .

Repeat this data line as often as necessary to give the stress-strain data.