prescribed isotropic active contraction

Module: solid

Category: material

Type string: "prescribed isotropic active contraction"

Parameters

Name	Description	Default	Range	Units
density	density	1	\(\ge 0\)	M/L^3
T0	T0	0	\(\in \mathbb{R}\)

Description

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

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

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

Example:

Isotropic contraction in a mixture containing a neo-Hookean solid.

<material id="1" type="solid mixture">
  <mat_axis type="local">0,0,0</mat_axis>
  <solid type="neo-Hookean">
    <E>1.0</E>
    <v>0</v>
  </solid>
  <solid type="prescribed isotropic active contraction">
    <T0 lc="2">1</T0>
  </solid>
</material>