Past Event: Oden Institute Seminar

Phase Field Modeling of Soft Tissue Fracture

Osman Gultekin, Research Fellow, Department of Aerospace Engineering and Engineering Mechanics, UT Austin

Abstract

Soft biological tissues, in particular arterial walls, have several mechanically significant constituents such as elastin and collagen fibers which are hierarchically structured to various degrees in the wall. Being a naturally synthesized polymer collagen stands out as the mechanically predominant component of the wall giving the arterial tissue an anisotropic and a highly non-linear mechanical response under physiological and supra-physiological loading cases.

The homeostasis of the wall may be disrupted due to several factors, e.g., Ehlers-Danlos syndrome, smoking, poor diet, hypertension, cystic medial necrosis etc. which lead to cardiovascular diseases, such as aneurysms, atherosclerosis and aortic dissection. When untreated those diseases eventually causes rupture of the wall leading to mortality and morbidity. Although the onset and the progression of diseases are palpably affected by the morphological and mechanical changes in the solid wall, little has been done so far in terms of computational modeling to better understand and predict the fracture in soft biological tissues.    

In this talk, I will first provide a synopsis of fibrous soft biological tissues where the emphasis is placed on the histology and the mechanics of the aortic wall and the blood clot. On the modeling side, we will step by step develop an anisotropic crack phase-field model to simulate the fracture in fibrous biological tissues. Geometric and material aspects of the anisotropy will be covered with examples verifying the intended theoretical descriptions. Efforts will be supplemented by some conceptual examples validating the experimental observations.

Our work lends itself very well to the future analyses of anatomically accurate and patient-specific in silico reconstructions of cardiovascular tissues. The phase-field approach developed tackles the technical problems originated from tracking discontinuities via cohesive zone or extended finite element methods, thereby shifting the paradigm in modeling fracture.

Biography

Osman Gultekin holds a PhD degree from Graz University of Technology in Austria. He worked there in the research group of Prof. Gerhard A. Holzapfel at the Institute of Biomechanics. In 2020, he received funding from European Commission Horizon 2020 Marie Sklodowska-Curie Actions Co-fund program and worked as a postdoc with Dr. Husnu Dal at Middle East Technical University in Turkey. Since July 2022, he works as a research fellow at Soft Tissue Biomechanics Laboratory headed by Dr. Manuel Rausch at the University of Texas at Austin. His research mainly focuses on the computational modeling of multi-physics problems in biomechanics as well as the mechanics of polymers and composites.