Sophisticated anisotropic arterial wall models showed significant differences in stresses and displacements compared to simple Neo-Hooke models, which exhibited unphysiologically large amplitudes.
In fluid-structure interaction simulations of arterial walls, simple isotropic models like Neo-Hooke fail to capture the fiber stiffening seen in sophisticated anisotropic models, leading to significant differences in simulated stresses and displacements.
Abstract Monolithic fluid–structure interaction (FSI) of blood flow with arterial walls is considered, making use of sophisticated nonlinear wall models. These incorporate the effects of almost incompressibility as well as of the anisotropy caused by embedded collagen fibers. In the literature, relatively simple structural models such as Neo-Hooke are often considered for FSI with arterial walls. Such models lack, both, anisotropy and incompressibility. In this paper, numerical simulations of idealized heart beats in a curved benchmark geometry, using simple and sophisticated arterial wall models, are compared: we consider three different almost incompressible, anisotropic arterial wall models as a reference and, for comparison, a simple, isotropic Neo-Hooke model using four different parameter sets. The simulations show significant quantitative and qualitative differences in the stresses and displacements as well as the lumen cross sections. For the Neo-Hooke models, a significantly larger amplitude in the in- and outflow areas during the heart beat is observed, presumably due to the lack of fiber stiffening. For completeness, we also consider a linear elastic wall using 16 different parameter sets. However, using our benchmark setup, we were not successful in achieving good agreement with our nonlinear reference calculation.
Balzani et al. (Tue,) conducted a other in Fluid-structure interaction of blood flow with arterial walls. Sophisticated anisotropic arterial wall models vs. Simple isotropic Neo-Hooke and linear elastic models was evaluated on Stresses, displacements, and lumen cross sections. Sophisticated anisotropic arterial wall models showed significant differences in stresses and displacements compared to simple Neo-Hooke models, which exhibited unphysiologically large amplitudes.