uncoupled prescribed isotropic active contraction

Module: solid

Category: material

Type string: "uncoupled prescribed isotropic active contraction"

Parameters

Name	Description	Default	Units
density	density	1	[M/L^3]
k	bulk modulus	0	[P]
pressure_model	pressure_model	0	[]
T0	T0	0	[]

Description

The material type for prescribed isotropic active contraction, in an uncoupled solid mixture, is uncoupled prescribed isotropic active contraction. This material must be combined with a stable uncoupled material that acts as a passive matrix, using a uncoupled solid mixture container as described in uncoupled solid mixture.

The active stress \(\boldsymbol{\sigma}^{a}\) for this material is given by

\[ \boldsymbol{\sigma}^{a}=J^{-1}T_{0}\mathbf{B}\,. \]

Note: If the solid material in the mixture is (nearly) incompressible, this isotropic contraction will cause no change in the deformation.

Example:

Isotropic contraction in a mixture containing a Mooney-Rivlin solid.

<material id="1" type="uncoupled solid mixture">
  <mat_axis type="local">0,0,0</mat_axis>
  <solid type="Mooney-Rivlin">
    <c1>1.0</c1>
    <c2>0</c2>
    <k>5.0</k>
  </solid>
  <solid type="prescribed isotropic active contraction uncoupled">
    <T0 lc="2">1</T0>
  </solid>
</material>