A comparative study of cohesive zone models for predicting delamination fracture behaviors of arterial wall

Ting Miao,Jingjing Wang,Zhangmu Miao,Liqiong Tian,Lisheng Liu,Xiaochang Leng,Chengjun Xu

doi:10.1515/phys-2020-0134

Abstract

AbstractArterial tissue delamination, manifested as the fracture failure between arterial layers, is an important process of the atherosclerotic plaque rupture, leading to potential life-threatening clinical consequences. Numerous models have been used to characterize the arterial tissue delamination fracture failure. However, only a few have investigated the effect of cohesive zone model (CZM) shapes on predicting the delamination behavior of the arterial wall. In this study, four types of CZMs (triangular, trapezoidal, linear–exponential, and exponential–linear) were investigated to compare their prediction of the arterial wall fracture failure. The Holzapfel–Gasser–Ogden (HGO) model was adopted for modeling the mechanical behavior of the aortic bulk material. The CZMs optimized during the comparison of the aortic media delamination simulations were also used to perform the comparative study of the mouse plaque delamination and human fibrous cap delamination. The results show that: (1) the numerical predicted the relationships of force–displacement in the delamination behaviors based on the triangular, trapezoidal, linear–exponential, and exponential–linear CZMs match well with the experimental measurements. (2) The traction–separation relationship results simulated by the four types of CZMs could react well as the corresponding CZM shapes. (3) The predicted load–load point displacement curves using the triangular and exponential–linear CZMs are in good agreement with the experimental data, relative to the other two shapes of CZMs. All these provide a new method combined with the factor of shape in the cohesive models to simulate the crack propagation behaviors and can capture the arterial tissue failure response well.

Highlights

Each year in the United States, 1.1 million people suffer from myocardial infarction with 40% fatality rate [1]
Four types of cohesive zone model (CZM) laws were used to model the delamination of atherosclerotic plaque [14] (Figure 5) and fibrous cap [15] (Figure 6)
The investigated results indicate that the prediction of the load– load point displacement curves, which is based on the CZMs, matches well with the experimental measurements of the aortic media peeling process

Summary

Introduction

Each year in the United States, 1.1 million people suffer from myocardial infarction with 40% fatality rate [1]. The arterial tissue fracture failure in terms of arterial wall delamination and separation is the main reason for atherosclerosis, which is likely to cause myocardial infarction [2]. The arterial wall is composed of three layers: intima, media, and adventitia. The media consists of a three-dimensional network of smooth muscle cells, elastin, and collagen fibers, and the adventitia consists of bundles of collagen fibers [3]. It is known that elastin is the major load-bearing components of the arterial wall at low strain and that collagen fibers contribute to the stiffening of the arterial tissue at high strain as they are gradually recruited [4]. The structure of the arterial tissue accounts for the distinct mechanical behaviors that the stress–strain curve shows a lower load response at the stage with larger displacement applied and a sharp increase in load with limit displacement.

Objectives

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Results

Conclusion