ISOTROPIC_HYPERELASTIC_LAW#

Description#

This object class defines the model for isotropic hyperelasticity in hyperelastic and hyper_viscoelastic models and potentials.

Syntax#

The syntax to specify an isotropic hyperelasticity object will consist of giving the keyword for a particular hyperelasticity model desired, followed by a list of appropriate coefficients which are dependent on the model chosen. The hyperelasticity type may be chosen among the following laws:

CODE

DESCRIPTION

arruda_boyce

Arruda-Boyce hyperelastic model

mooney

Mooney hyperelastic model

rivlin

Rivlin hyperelastic model

neo_hookean

Neo-Hookean law

hookean_log

Logarithmic Hookean law

The structure of the object is summarized below:

***behavior hyper_elastic \(~\,\) **isotropic_hyperelasticity <HYPERELASTIC_LAW> \(~\,\) **model_coef \(~\,~\,~\,\) … [ **pull_back ]

Stored Variables

The stored variables for this object include the Green-Lagrange total strain tensor, the Cauchy stress tensor, and the strain energy density \(W\). As an auxiliary output variable, the Piola-Kirchhoff stress tensor:

(420)#\[\ten S = \pder{W}{\ten E}\]

is stored but not saved during the calculation. The post-processor prefixes used for these variables are the following:

prefix

size

description

default

eto

T-2

Green-Lagrange strain

yes

sig

T-2

Cauchy stress

yes

welas

S

strain energy density

yes

If the option **pull_back is given, the Piola-Kirchhoff stress tensor is requested as output 1Only for the ****simulate calculation definition..