Computational modeling of progressive damage and rupture in fibrous biological tissues: Application to aortic dissection

This study analyzes the highly lethal clinical condition of aortic dissections from a numerical perspec-
tive. On the basis of previous contributions by Gültekin et al. (Comput. Methods Appl. Mech. Engrg.
312:542–566, 2016 and 331:23–52, 2018), we apply a holistic geometrical approach to fracture, namely the
crack phase-field which inherits the intrinsic features of gradient damage and variational fracture mechan-
ics. The continuum framework captures anisotropy, is thermodynamically consistent and based on finite
strains. The balance of linear momentum and the crack evolution equation govern the coupled mechani-
cal and phase-field problem. The solution scheme features the robust one–pass operator–splitting algorithm
upon temporal and spatial discretizations. Subsequently, based on experimental data of diseased human tho-
racic aortic samples, the elastic material parameters are identified followed by a sensitivity analysis of the
anisotropic phase-field model. Finally, we simulate an incipient propagation of an aortic dissection within
a multi–layered segment of a thoracic aorta that involves a prescribed initial tear. The finite element results
demonstrate a severe damage zone around the initial tear, exhibit a helical crack pattern, also observed in
clinics, that aligns with the orientation of fibers. There is hope that the current contribution can provide
some avenues for further investigations of this disease.