## 1 Introduction
The reduced relaxation function was modified by integrating a rational equation as a corrective factor to simulate the strain-dependent relaxation effects accurately. [PERSON] et al. [16] proposed a regression model capable of estimating the pre-strain of a human abdominal  
Figure 1: Schematic of the aorta and its segments. aorta. A database including the length and diameter of the abdominal aorta, heart weight, thickness of the left ventricle, and degree of atherosclerosis was obtained by evaluating 156 male cadavers. In the database, a significant correlation between the age, pre-strain, diameter, and atherosclerosis was identified, which was best fitted to a power law equation. [PERSON] et al. [17] studied the biomechanical failure properties and histological composition of a human non-aneurysmal aorta. They extracted the material specimens from 26 human cadavers and measured the failure stress, tension, and strain in circumferentially-oriented strips. [PERSON] et al. [18] defined the biomechanical parameters of a healthy human abdominal aorta and developed materials for aortic phantom production. These phantoms used in the training of endovascular treatment must exhibit the same morphology and mechanical behavior properties as those of the aorta of the patient. Therefore, they conducted ex vivo experiments by uniaxial tensile and dynamic simple shear testing of six healthy human abdominal aortas to confirm the biomechanical parameters accurately. [PERSON] et al. [19] examined the in vitro anisotropic mechanical behavior of canine aortic tissue and focused on the spatial variations in its properties in the axis direction of the vessel. Hence, uniaxial stretch tests on canine aortic specimens in the circumferential and longitudinal directions, as well as histological examinations to identify the fiber orientations of the tissues were performed. In addition, they examined a constitutive model that contained both phenomenological and structural elements to consider the macroscopic and microstructural behaviors of the tissue. Further, precise constitutive models of soft biological tissue coupled with appropriate numerical approaches have been continuously developed from these experimental results. In other words, it has been developed as a phenomenological approach that describes the macroscopic characteristic of a material as a continuum in order to simulate the mechanical behavior including the stiffness and direction of fibers of aortic material [20; 21; 22; 23]. Although such studies were conducted, they were not sufficiently large in scale to study the effects of the age range, the numerical model applied for material nonlinear damage modeling, and the criterion for rupture of the aortic tissue. Therefore, in this study, the numerical simulation approach was suggested to simulate material properties according to age. In the step for determining the material properties, the uniaxial tensile tests were conducted on porcine aortic specimens in the circumferential and longitudinal directions, and the numerical simulations that the Holzapfel-Gasser-Ogden (HGO) model [22; 23; 24] was applied to simulate the behavior of the arterial tissue were performed using the ABAQUS finite element program. The results between experiment and numerical simulation were compared to determine the reliability of the simulation. In addition, the experimental results for the healthy human abdominal aorta specimens were investigated and analyzed based on age, and the material constants associated with the elastic modulus, stress, and strain in the numerical model were estimated from the numerical simulations according to age. From these results, the correlation between age and material constants was examined, and the formulae for estimating material constants based on age were proposed.