Publication detail

Impact of isotropic constitutive descriptions on the predicted peak wall stress in abdominal aortic aneurysms

MAN, V. POLZER, S. GASSER, T. NOVOTNÝ, T. BURŠA, J.

Original Title

Impact of isotropic constitutive descriptions on the predicted peak wall stress in abdominal aortic aneurysms

Type

journal article in Web of Science

Language

English

Original Abstract

Biomechanics-based assessment of Abdominal Aortic Aneurysm (AAA) rupture risk has gained considerable scientific and clinical momentum. However, computation of peak wall stress (PWS) using state-of-the-art finite element models is time demanding. This study investigates which features of the constitutive description of AAA wall are decisive for achieving acceptable stress predictions in it. Influence of five different isotropic constitutive descriptions of AAA wall is tested; models reflect realistic non-linear, artificially stiff non-linear, or artificially stiff pseudo-linear constitutive descriptions of AAA wall. Influence of the AAA wall model is tested on idealized (n=4) and patient-specific (n=16) AAA geometries. Wall stress computations consider a (hypothetical) load-free configuration and include residual stresses homogenizing the stresses across the wall. Wall stress differences amongst the different descriptions were statistically analyzed. When the qualitatively similar non-linear response of the AAA wall with low initial stiffness and subsequent strain stiffening was taken into consideration, wall stress (and PWS) predictions did not change significantly. Keeping this non-linear feature when using an artificially stiff wall can save up to 30% of the computational time, without significant change in PWS. In contrast, a stiff pseudo-linear elastic model may underestimate the PWS and is not reliable for AAA wall stress computations.

Keywords

Abdominal aortic aneurysm, Wall stress, Non-linear material model

Authors

MAN, V.; POLZER, S.; GASSER, T.; NOVOTNÝ, T.; BURŠA, J.

Released

1. 3. 2018

Publisher

Elsevier

Location

Amsterdam, Nizozemsko

ISBN

1350-4533

Periodical

MEDICAL ENGINEERING & PHYSICS

Year of study

53

Number

1

State

United Kingdom of Great Britain and Northern Ireland

Pages from

49

Pages to

57

Pages count

9

URL

https://www.sciencedirect.com/science/article/pii/S1350453318300080?via%3Dihub

BibTex

@article{BUT152171,
  author="MAN, V. and POLZER, S. and GASSER, T. and NOVOTNÝ, T. and BURŠA, J.",
  title="Impact of isotropic constitutive descriptions on the predicted peak wall stress in abdominal aortic aneurysms",
  journal="MEDICAL ENGINEERING & PHYSICS",
  year="2018",
  volume="53",
  number="1",
  pages="49--57",
  doi="10.1016/j.medengphy.2018.01.002",
  issn="1350-4533",
  url="https://www.sciencedirect.com/science/article/pii/S1350453318300080?via%3Dihub"
}