Characterization of material properties of aorta from oscillatory pressure tests

Abstract

Traumatic Aorta Rupture (TAR), also known as Traumatic Rupture of Thoracic Aorta (TRA), is one of the major causes of fatalities in motor vehicle accidents. This issue has been studied in the past; however, the results of the suggested mechanisms are speculative and inconclusive. One cause for these speculations is an incomplete understanding of the material properties of aorta. Therefore, the goal of this experiment was to characterize the dynamic structural response of the aorta to a biaxial loading. Seven samples were subjected to a pressure oscillation input ranging from 7kPa to 76kPA at a frequency ranging from .5Hz to 5Hz. The results were presented in the form of pressure versus volumetric strain which showed an increase in both phase and magnitude of the linear modulus. Initial modeling was completed utilizing hyperelastic constitutive equations. The results of this study will be used to determine a viscoelastic constitutive model and a finite element model for the aorta material. © 2010 Springer-Verlag.