Effects of non-uniform wall properties on stress distribution in an abdominal aortic aneurysm, considering nonlinear constitutive equations

In this study, stress distribution in the aneurismal wall of the abdominal aortic is addressed. Full equilibrium equations derived from the thick-wall theory are solved using the well-known Finite Element Method (FEM). Nine-node quadratic rectangular plane elements are employed for the spatial discretization of the computational domain. Nonlinear constitutive equations and non-uniform wall properties are taken into consideration. The results of this investigation show that in addition to the aneurysm size, some other factors may significantly affect stress distribution in aneurismal wall. Factors such as wall thickness, blood pressure and longitudinal tension have been identified for both uniform and non-uniform wall properties. Having numerically simulated different cases, it is demonstrated that longitudinal stress is the maximum stress in the wall, and it is not significantly affected by the uniformity of wall stiffness.