  The viscoelastic properties of arterial tissue dictate vessel behavior in
certain disease states, injury modalities, and during some endovascular
procedures. In this study, we characterized the viscoelastic mechanical
response of porcine abdominal aortic tissue via uniaxial mechanical experiments
on vascular tissue samples coupled with full-field surface strain measurements
using the 2-D digital image correlation (DIC) technique. The measured stress
relaxation response and intimal surface strain field were used to identify
material parameters for a proposed viscoelastic anisotropic (VA) constitutive
model of the passive arterial wall. The obtained results show that the VA
constitutive model is able to capture the viscoelastic mechanical behavior of
the arterial tissue over clinically-relevant time scales. The identified
material model and numerical simulations provide a comprehensive description of
the passive viscoelastic tissue properties of the arterial wall, and a
quantitative understanding of the spatial and directional variability
underlying arterial tissue mechanical behavior.
