| Description |
Vascular mechanics plays a key role in both health and disease. Therefore, the mechanical properties of vessels have been under study for over a century. This thesis reports research with two computational models designed to better understand vessel mechanics in complex loading scenarios. Numerous methodologies have been utilized to evaluate the mechanical behavior of blood vessels, including distending arterial rings to investigate circumferential behavior, a configuration commonly used in wire myography. We previously used this configuration to experimentally characterize microstructural damage in cerebral arteries that may transpire in clinical procedures and due to trauma. However, due to the complexity of loading, we were not able to quantify strains throughout the vessel experimentally. As a consequence, we were not able to relate microstructural damage with vessel strains in all parts of the vessel. Thus, the aim of the current investigation was to quantify strains throughout the arterial ring by using a computational model. To achieve our goal, we created a finite element (FE) model of the experiment using FEBio. In the model, we observed complex vessel strain distributions along the circumference. Most vessel strains were observed to vary considerably through the wall thickness in regions near the needles, but circumferential strains remained largely constant throughout the ring. In this research, another computational model was constructed to understand the significance of perfusion in cerebral arteries' strain rate dependence. Although many investigators have attempted to characterize the strain rate dependence of arteries experimentally, there has been disagreement in the results. In our previous investigation, our lab observed strain rate dependence in dynamically-loaded middle cerebral arteries (MCAs) in rats. We hypothesized that perfusion was at least partly responsible for the observed behavior and designed a computational model using LS-DYNA to test our hypothesis. As expected, we observed a contribution of perfusion to strain rate dependence in the circumferential and the radial directions. However, it was not sufficient to influence experimentally witnessed axial strain rate dependence. |
