Publication detail

Importance of experimental evaluation of structural parameters for constitutive modelling of aorta

FISCHER, J. TURČANOVÁ, M. MAN, V. HERMANOVÁ, M. BEDNAŘÍK, Z. BURŠA, J.

English title

Importance of experimental evaluation of structural parameters for constitutive modelling of aorta

Type

journal article in Web of Science

Language

en

Original abstract

The study compares stresses and strains in the aortic wall derived using different constitutive models for various stress-strain conditions. Structure-based constitutive models with two fibre families with (GOH) and without (HGO) dispersion of collagen fibres are compared. The constitutive models were fitted to data from equibiaxial tension tests of two separated layers of the porcine aortic wall. The initial fit was evaluated with unrestricted parameters and subsequently, the mean angles of the fibre families and the angular dispersion were fixed to the values obtained from histology. Surprisingly, none of the tested models was capable to provide a good quality fit with histologically obtained structural parameters. Fitting the HGO model to experimental data resulted in two fibre families under angles close to +/- 45 degrees, while the GOH model resulted in a nearly isotropic fibre distribution. These results indicate that both of these models suffer from the absence of isotropic strain stiffening. After having modified both models with corresponding additional members based on the Yeoh model of matrix, we obtained a perfect fit to the measured data while keeping the structural histology-based parameters. Finally, significant differences in compliance and resulting stresses and strains between different models are shown by means of simulations of uniaxial tension test, equibiaxial tension tests and inflation of the aorta.

English abstract

The study compares stresses and strains in the aortic wall derived using different constitutive models for various stress-strain conditions. Structure-based constitutive models with two fibre families with (GOH) and without (HGO) dispersion of collagen fibres are compared. The constitutive models were fitted to data from equibiaxial tension tests of two separated layers of the porcine aortic wall. The initial fit was evaluated with unrestricted parameters and subsequently, the mean angles of the fibre families and the angular dispersion were fixed to the values obtained from histology. Surprisingly, none of the tested models was capable to provide a good quality fit with histologically obtained structural parameters. Fitting the HGO model to experimental data resulted in two fibre families under angles close to +/- 45 degrees, while the GOH model resulted in a nearly isotropic fibre distribution. These results indicate that both of these models suffer from the absence of isotropic strain stiffening. After having modified both models with corresponding additional members based on the Yeoh model of matrix, we obtained a perfect fit to the measured data while keeping the structural histology-based parameters. Finally, significant differences in compliance and resulting stresses and strains between different models are shown by means of simulations of uniaxial tension test, equibiaxial tension tests and inflation of the aorta.

Keywords in English

Soft tissue; Collagen; Fibre direction; Polarized light microscopy; Histogram; Constitutive modelling

Released

25.01.2023

Publisher

ELSEVIER

Location

AMSTERDAM

ISSN

1751-6161

Volume

138

Number

2

Pages from–to

105615-1–105615-8

Pages count

8

BIBTEX


@article{BUT181391,
  author="Jiří {Fischer} and Michaela {Turčanová} and Vojtěch {Man} and Markéta {Hermanová} and Zdeněk {Bednařík} and Jiří {Burša},
  title="Importance of experimental evaluation of structural parameters for constitutive modelling of aorta",
  year="2023",
  volume="138",
  number="2",
  month="January",
  pages="105615-1--105615-8",
  publisher="ELSEVIER",
  address="AMSTERDAM",
  issn="1751-6161"
}