A COUPLED EXPERIMENTAL AND NUMERICAL APPROACH TO CHARACTERIZE THE ANISOTROPIC MECHANICAL BEHAVIOR OF AORTIC TISSUES

Nowadays, the investigation of aortic wall biomechanics is a fundamental tool in clinicalresearch and vascular prosthesis design. This study aims at analyzing the biomechanicalbehavior of aortic tissues using a coupled experimental and computational approach. Con-sidering the typical fiber-reinforced configuration of aortic tissues, uni-axial tensile tests alongsix different loading directions were performed on specimens from pig aorta. Starting from theobtained experimental data, a suitable constitutive framework was defined and a methodologyfor the identification of the constitutive parameters was developed using the inverse analysis ofmechanical tests. Transversal stretch versus loading stretch and nominal stress versus loadingstretch curves were evaluated, showing the anisotropic and nonlinear mechanical behaviordetermined by tissue conformation with fibers distributed along preferential directions. Indetail, experimental data showed different mechanical responses between longitudinal andcircumferential directions, with a greater tissue stiffness along the longitudinal one. The reli-ability of the developed constitutive framework was evaluated by the comparison betweenexperimental data and model results. The mentioned analysis can be considered as a useful toolfor the development of reliable computational models, which allow a better understanding ofthe pathophysiology of cardiovascular diseases and can be applied for a proper planning ofsurgical procedures.