Finite element modeling of human artery tissue with a nonlinear multi-mechanism inelastic material

Due to limited experimental data and a lack of understanding of the underlying microstructural deformation mechanisms involved, modeling of material behavior of biomechanical tissues presents a rather formidable task. In this dissertation, a nonlinear multi-mechanism inelastic material model is introduced for modeling vascular tissue, collagen recruitment and elastin degradation. The model is implemented into the commercial finite element software package ANSYS with user programmable features. Although the idea of using several deformation mechanisms in the same material model is by no means novel, it is the first time such model is being implemented in a commercial finite element package and applied to a numerical study of physiological processes taking place inside the vascular walls. Two numerical examples are presented: a simulation of angioplasty procedure, and a finite element analysis of fusiform aneurysm development and growth. This is by far not the exhaustive list of possible applications of the developed material model; implementation in a commercial finite element code will help facilitate innovative developments, including new ways to surgically treat vascular disorders