A Crack Phase-field Model to Analyze Aortic Dissections


Creative Commons License

Holzapfel G. A. , Gültekin O., Hager S. P. , Dal H.

COMPLAS 2019 15th International Conference on Computational Plasticity–Fundamentals and Applications, Barcelona, Spain, 3 - 05 September 2019, pp.1

  • Publication Type: Conference Paper / Summary Text
  • City: Barcelona
  • Country: Spain
  • Page Numbers: pp.1

Abstract

This study analyzes the lethal clinical condition of aortic dissections from a numerical point of view.On the basis of our previous contributions [1,2], we apply a holistic geometrical approach to fracture,namely the crack phase-field,  which inherits the intrinsic features of gradient damage and variationalfracture mechanics.   The continuum framework captures anisotropy,  is thermodynamically consistentand based on finite strains.  The balance of linear momentum and the crack evolution equation governthe  coupled  mechanical  and  phase-field  problem.   The  solution  scheme  features  the  robust  one–passoperator–splitting algorithm upon temporal and spatial discretizations.  Based on experimental data ofdiseased  human  thoracic  aortic  samples,  the  elastic  material  parameters  are  identified  followed  by  asensitivity analysis of the anisotropic phase-field model. Finally, we simulate an incipient propagation ofan aortic dissection within a multi–layered segment of a thoracic aorta that involves a prescribed initialtear [3].  The finite element results demonstrate a severe damage zone around the initial tear, exhibit arather helical crack pattern, which aligns with the fiber orientation.