Publication detail

Simulation of residual stresses (strains) in arteries

POLZER, S. BURŠA, J.

Original Title

Simulation of residual stresses (strains) in arteries

English Title

Simulation of residual stresses (strains) in arteries

Type

conference paper

Language

en

Original Abstract

Residual stresses and strains contribute substan-tially to stress-strain states in arteries. They manifest them-selves by opening of the artery after having been cut longitudi-nally and can be quantified by means of the opening angle of a ring cut out of the artery and cut longitudinally afterwards. The magnitude of the opening angle changes with species, age of the individual, artery location, etc. Although the magnitude of these stresses appears slight, they can influence the stress (and strain) distribution in the arterial wall substantially by reducing the extreme values throughout the wall. Their surpri-singly high influence on the resulting stresses is given by the non-linear stress-strain characteristics of vascular wall. When applied to the blood pressure, the uniform stress and uniform strain hypotheses have been formulated to explain this pheno-menon. The usual way of their modeling is based on using a model with the geometry of the opened arterial ring; the resi-dual stresses are then induced in the model by closing it into the original approximately circular shape. This method, how-ever, is not applicable for more complex non-symmetric ar-terial geometries, because the induced strains depend on local bending stiffness. Therefore another approach is used in the paper, based on introducing an interference between two lay-ers of aorta represented in the model. The method is demon-strated with a circular ring used typically in experimental assessment of residual strains and results of both methods are compared. In addition, the proposed interference method is numerically more stable, because of the two orders lower dis-placements, and it is able to induce constant strains through-out all the wall thickness by using more than two layers in the arterial wall model.

English abstract

Residual stresses and strains contribute substan-tially to stress-strain states in arteries. They manifest them-selves by opening of the artery after having been cut longitudi-nally and can be quantified by means of the opening angle of a ring cut out of the artery and cut longitudinally afterwards. The magnitude of the opening angle changes with species, age of the individual, artery location, etc. Although the magnitude of these stresses appears slight, they can influence the stress (and strain) distribution in the arterial wall substantially by reducing the extreme values throughout the wall. Their surpri-singly high influence on the resulting stresses is given by the non-linear stress-strain characteristics of vascular wall. When applied to the blood pressure, the uniform stress and uniform strain hypotheses have been formulated to explain this pheno-menon. The usual way of their modeling is based on using a model with the geometry of the opened arterial ring; the resi-dual stresses are then induced in the model by closing it into the original approximately circular shape. This method, how-ever, is not applicable for more complex non-symmetric ar-terial geometries, because the induced strains depend on local bending stiffness. Therefore another approach is used in the paper, based on introducing an interference between two lay-ers of aorta represented in the model. The method is demon-strated with a circular ring used typically in experimental assessment of residual strains and results of both methods are compared. In addition, the proposed interference method is numerically more stable, because of the two orders lower dis-placements, and it is able to induce constant strains through-out all the wall thickness by using more than two layers in the arterial wall model.

Keywords

Residual stress, interference method, two-layer model, opening angle

RIV year

2012

Released

15.02.2012

Publisher

Springer

Location

Budapest

ISBN

978-3-642-23507-8

Book

IFMBE Proceedings, Volume 37

Pages from

454

Pages to

457

Pages count

4

Documents

BibTex


@inproceedings{BUT75647,
  author="Stanislav {Polzer} and Jiří {Burša}",
  title="Simulation of residual stresses (strains) in arteries",
  annote="Residual stresses and strains contribute substan-tially to stress-strain states in arteries. They manifest them-selves by opening of the artery after having been cut longitudi-nally and can be quantified by means of the opening angle of a ring cut out of the artery and cut longitudinally afterwards. The magnitude of the opening angle changes with species, age of the individual, artery location, etc. Although the magnitude of these stresses appears slight, they can influence the stress (and strain) distribution in the arterial wall substantially by reducing the extreme values throughout the wall. Their surpri-singly high influence on the resulting stresses is given by the non-linear stress-strain characteristics of vascular wall. When applied to the blood pressure, the uniform stress and uniform strain hypotheses have been formulated to explain this pheno-menon. The usual way of their modeling is based on using a model with the geometry of the opened arterial ring; the resi-dual stresses are then induced in the model by closing it into the original approximately circular shape. This method, how-ever, is not applicable for more complex non-symmetric ar-terial geometries, because the induced strains depend on local bending stiffness. Therefore another approach is used in the paper, based on introducing an interference between two lay-ers of aorta represented in the model. The method is demon-strated with a circular ring used typically in experimental assessment of residual strains and results of both methods are compared. In addition, the proposed interference method is numerically more stable, because of the two orders lower dis-placements, and it is able to induce constant strains through-out all the wall thickness by using more than two layers in the arterial wall model.",
  address="Springer",
  booktitle="IFMBE Proceedings, Volume 37",
  chapter="75647",
  howpublished="electronic, physical medium",
  institution="Springer",
  year="2012",
  month="february",
  pages="454--457",
  publisher="Springer",
  type="conference paper"
}