A continuum mechanics constitutive framework for transverse isotropic soft tissues Articles uri icon

publication date

  • March 2018

start page

  • 209

end page

  • 224

volume

  • 112

international standard serial number (ISSN)

  • 0022-5096

electronic international standard serial number (EISSN)

  • 1873-4782

abstract

  • In this work, a continuum constitutive framework for the mechanical modelling of soft tissues that incorporates strain rate and temperature dependencies as well as the transverse isotropy arising from fibres embedded into a soft matrix is developed. The constitutive formulation is based on a Helmholtz free energy function decoupled into the contribution of a viscous-hyperelastic matrix and the contribution of fibres introducing dispersion dependent transverse isotropy. The proposed framework considers finite deformation kinematics, is thermodynamically consistent and allows for the particularisation of the energy potentials and flow equations of each constitutive branch. In this regard, the approach developed herein provides the basis on which specific constitutive models can be potentially formulated for a wide variety of soft tissues. To illustrate this versatility, the constitutive framework is particularised here for animal and human white matter and skin, for which constitutive models are provided. In both cases, different energy functions are considered: Neo-Hookean, Gent and Ogden. Finally, the ability of the approach at capturing the experimental behaviour of the two soft tissues is confirmed.

keywords

  • Soft tissues
    Strain rate dependence
    Temperature dependence
    White matter
    Skin