Phase-field approach to model fracture in human aorta

Date

2019-08-23

Author

Gültekin, Osman
Holzapfel, Gerhard A.
Dal, Hüsnü

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Over the last decades the supra-physiological and pathological aspects of arterial tissues have become a prominent research topic in computational biomechanics in terms of constitutive modeling considering damage and fracture [1]. The current study presents a variational approach to the fracture of human arterial walls, featuring a thermodynamically consistent, gradient-type, diffusive crack phase-field approach. A power balance renders the Euler-Lagrange equations of the multi-field problem, i.e. the deformation and the phase-field. The respective constitutive model is essentially anisotropic and in accordance with the tissue morphology. A novel anisotropic phase-field model accounts for not only the altered crack patterns with respect to the orientation collagen fibers, but also the distinct strain-energy contributions due to isotropic and anisotropic parts [2, 3, 4]. The prediction of the crack pattern are studied via single edge-notched tests to ascertain anisotropic features of the model. Aside from that, a novel simple concept of design, i.e. an idealized cylindrical model of the multi-layered thoracic aortic wall with a notch representing the initial tear provides insights regarding the nascent crack growth associated with aortic dissection. In particular, the analysis indicates crack onset and progression around the initial tear while aligning with the direction of the first fiber family, capturing the helical pattern of the aortic dissection in the aorta [4]. The results also lay bare the need for a systematic experimental characterization of the human aorta for an inclusive parameter identification

Subject Keywords

Crack phase-field model, Human aorta, Aortic dissection

URI

http://iwpdf.ae.metu.edu.tr/book_of_abstracts.pdf#page=35
https://hdl.handle.net/11511/83566

Conference Name

The 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials IWPDF (2019)

Collections

Department of Mechanical Engineering, Conference / Seminar

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Numerical aspects of anisotropic failure in soft biological tissues favor energy-based criteria: A rate-dependent anisotropic crack phase-field model Gueltekin, Osman; Dal, Hüsnü; Holzapfel, Gerhard A. (2018-04-01) A deeper understanding to predict fracture in soft biological tissues is of crucial importance to better guide and improve medical monitoring, planning of surgical interventions and risk assessment of diseases such as aortic dissection, aneurysms, atherosclerosis and tears in tendons and ligaments. In our previous contribution (Gultekin et al., 2016) we have addressed the rupture of aortic tissue by applying a holistic geometrical approach to fracture, namely the crack phase-field approach emanating from va...
A PHASE FIELD APPROACH TO MODEL FRACTURE OF ARTERIAL WALLS GÜLTEKİN, Osman; Dal, Hüsnü; HOLZAPFEL, Gerhard A (2016-06-10) This study uses a recently developed phase-field approach to model fracture of arterial walls with an emphasis on aortic tissues. We start by deriving the regularized crack surface to overcome complexities inherent in sharp crack discontinuities, thereby relaxing the acute crack surface topology into a diffusive one. In fact, the regularized crack surface possesses the property of Gamma-Convergence, i.e. the sharp crack topology is restored with a vanishing length-scale parameter. Next, we deal with the con...
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Phase-field models for the failure of anisotropic continua Dal, Hüsnü; Aksu Denli, Funda; Holzapfel, Gerhard (null; 2017-03-10) This study presents a phase-field approach for an anisotropic continuum to model fracture of biological tissues and fibre-reinforced composites. We start by deriving the regularized crack surface to overcome complexities inherent in sharp crack discontinuities, thereby relaxing the acute crack surface topology into a diffusive one. In fact, the regularized crack surface possesses the property of Gamma-Convergence, i.e. the sharp crack topology is restored with a vanishing length-scale parameter. Next, we de...

Citation Formats

O. Gültekin, G. A. Holzapfel, and H. Dal, “Phase-field approach to model fracture in human aorta,” presented at the The 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials IWPDF (2019), Ankara, Türkiye, 2019, Accessed: 00, 2021. [Online]. Available: http://iwpdf.ae.metu.edu.tr/book_of_abstracts.pdf#page=35.