%0 PDF %T Growth and Remodeling of Human Abdominal Aorta Aneurysms %A Lin, Wenjian. %D 2018-06-04T10:04:04.934-04:00 %8 2018-06-04 %R http://localhost/files/sq87c6162 %X Abstract: The human abdominal aorta aneurysm (AAA) has been increasingly modeled as a continuous deformation process in recent years. Changes in both structure and material of artery wall have been studied and analyzed. This thesis aims to address key issues related to the nonlinear modeling of AAA development, and a continuous growth and remodeling (G&R) model was proposed. The model incorporates artery wall material growth and degradation, microstructure remodeling and artery vessel stability to simulate and predict the aneurysm development. The kinematic model is described in which simultaneously occurring growth and deformation are considered as a sequence of two mappings, one representing stress-free growth and the other representing the deformations of the tissue due to stresses acting on the tissue. In the simulation, we combine the growth theory and remodeling theory, and apply it to the simulation of patient aneurysm development. Both microstructure geometry and component mass changes are accounted for. The fundamental concepts of the nonlinear theory of elasticity are addressed and suitable continuous material models are formulated. The model depicts the changes of the outer radius of a dilating abdominal aorta as a function of axial position over a twelve-year period with an applied pressure of 16 kPa (120 mmHg). Numerical results show that over this period, the maximum dilation increased from 12.94 mm to about 35 mm, and the elastin dropped from 60% to less than 20%. From years 8 to 12, as the bulge expanded, the maximum von Mises stress increased almost four times, from 235 to 925 kPa. Mixture theory of growth and remodeling predicted the development of inhomogeneous mechanical properties and dilatation of the diseased section of the arterial wall. The rate of expansion depended primarily on the rate of production and removal of elastin and collagen as well as on the change in fiber microstructure.; Thesis (Ph.D.)--Tufts University, 2018.; Submitted to the Dept. of Civil Engineering.; Advisor: Luis Dorfmann.; Committee: Helen Suh, Robert Viesca, James Adler, and Robert Peattie.; Keyword: Biomechanics. %[ 2022-10-11 %9 Text %~ Tufts Digital Library %W Institution