PSI - Issue 45

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 45 (2023) 88–95

17th Asia-Pacific Conference on Fracture and Strength and the 13th Conference on Structural Integrity and Failure (APCFS 2022 & SIF 2022) Failure investigation and stresses in abdominal aortic aneurysms fluid-structure interaction biomechanics: Effect of nonlinear material properties and presence of intraluminal thrombus Xiaochen Wang a, *, Mergen H. Ghayesh a , Andrei Kotousov a , Anthony C. Zander a and Peter J. Psaltis a,b,c a School of Electrical and Mechanical Engineering, University of Adelaide, Adelaide, SA 5005, Australia b Vascular Research Centre, Lifelong Health Theme, South Australian Health & Medical Research Institute (SAHMRI), Adelaide, SA 5000, Australia c Adelaide Medical School, University of Adelaide, Adelaide, SA 5005, Australia d Department of Cardiology, Central Adelaide Local Health Network, Adelaide, SA 5000, Australia Abstract Abdominal aortic aneurysm (AAA) rupture has become a prevalent cause of death and is responsible for approximately 200,000 deaths annually worldwide. Due to the fact that abdominal aortic aneurysms are permanent progressive dilatations and asymptomatic until rupture, there is a rising need to study the characteristics of the mechanics of disease so that it can be recognised earlier on, thus preventing the patients from risks. This paper analyses the relationship between the nonlinear material hyperelasticity variability and the presence of intraluminal thrombosis (ILT) in a biomechanical computational model of an abdominal aortic aneurysm via the fluid-structure interaction technique. Current clinical interventions of AAA highly rely on the aneurysm size; however, evidence has shown that many small lesions rupture. One possible cause of this phenomenon is ILT, as in over 70% of patients with AAA, ILT can be found and presented irregular covered on the intimal side of AAA. Moreover, the embedded fibres in the artery wall exhibit anisotropy, and neglecting fibre dispersion can oversimplify the results of AAA modelling. The biomechanical model presented in this work takes into account viscoelastic artery wall, pulsatile fluid velocity and pressure, non-Newtonian behaviour of blood, and interaction between the blood and the artery wall. The impact on wall stresses, deformation and flow patterns are focused and compared to conduct this sensitivity analysis of numerical prediction. The results demonstrate that the presence of an ILT significantly affects the risk of rupture and the variability of the material hyperelasticity

* Corresponding author. Tel.: +0415927771. E-mail address: xiaochen.wang@adelaide.edu.au

2452-3216 © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Prof. Andrei Kotousov

2452-3216 © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Prof. Andrei Kotousov 10.1016/j.prostr.2023.05.018