3D large strain hierarchical multiscale analysis of soft fiber-reinforced tissues: application to a degraded arterial wall
ISSN: 0264-4401
Article publication date: 29 March 2022
Issue publication date: 7 June 2022
Abstract
Purpose
The purpose is to analyze the mechanical behavior of the arterial wall in the degraded region of the arterial wall and to determine the stress distribution, as an important factor for predicting the potential failure mechanisms in the wall. In fact, while the collagen fiber degradation process itself is not modeled, zones with reduced collagen fiber content (corresponding to the degradation process) are assumed. To do so, a local weakness in the media layer is considered by defining representative volume elements (RVEs) with different fiber collagen contents in the degraded area to investigate the mechanical response of the arterial wall.
Design/methodology/approach
A three-dimensional (3D) large strain hierarchical multiscale technique, based on the homogenization and genetic algorithm (GA), is utilized to numerically model collagen fiber degradation in a typical artery. Determination of material constants for the ground matrix and collagen fibers in the microscale level is performed by the GA. In order to investigate the mechanical degradation, two types of RVEs with different collagen contents in fibers are considered. Each RVE is divided into two parts of noncollagenous matrix and collagen fiber, and the part of collagen fiber is further divided into matrix and collagen fibrils.
Findings
The von Mises stress distributions on the inner and outer surfaces of the artery and the influence of collagen fiber degradation on thinning of the arterial wall in the degraded area are thoroughly studied. Comparing the maximum stress values on outer and inner surfaces in the degraded region shows that the inner surface is under higher stress states, which makes it more prone to failure. Furthermore, due to the weakness of the artery in the degraded area, it is concluded that the collagen fiber degradation considerably reduces the wall thickness in the degraded area, leading to an observable local inflation across the degraded artery.
Originality/value
Considering that little attention has been paid to multiscale numerical modeling of collagen fiber degradation, in this paper a 3D large strain hierarchical multiscale technique based on homogenization and GA methods is presented. Therefore, while the collagen fiber degradation process itself is not modeled in this study, zones with reduced collagen fiber content (corresponding to the degradation process) are assumed.
Keywords
Acknowledgements
The authors wish to gratefully acknowledge the technical support of the High Performance Computing Lab, School of Civil Engineering, University of Tehran. Furthermore, the authors appreciate the cooperation of Farshid Fathi, University of Tehran, at earlier stages of this work. The physiological comments by Elaheh Jafari, Tehran University of Medical Sciences, is also appreciated.
Conflict of interest: The authors declare that they have no conflict of interest.
Citation
Hatefi Ardakani, S., Fatemi Dehaghani, P., Moslemzadeh, H. and Mohammadi, S. (2022), "3D large strain hierarchical multiscale analysis of soft fiber-reinforced tissues: application to a degraded arterial wall", Engineering Computations, Vol. 39 No. 6, pp. 2108-2143. https://doi.org/10.1108/EC-05-2021-0289
Publisher
:Emerald Publishing Limited
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