Reevaluation of Arterial Constitutive Relations: A FINITE-DEFORMATION APPROACH

Abstract

The purpose of this investigation was to use the finite-deformation theory of elasticity to interpret pressure-diameter data for in situ canine aortas and other arterial response data reported in the literature. A meaningful mechanical property for arterial tissue was identified as ∂W₁/∂I, the partial derivative of the strain-energy density function with respect to the first strain invariant. An exponential function was found to characterize the mechanical property ∂W₁/∂I for all arteries considered. Thin-walled tube stress approximations were found to result in inaccurate values for arterial stresses and incremental elastic mechanical properties. Wave speeds calculated using ∂W₁/∂I for these arterial tissues agreed well with experimental measurements of wave speeds reported in the literature. Elevated values for strain-energy density were found in the inner arterial tissue layers. These high values for strain energy may contribute to atherogenesis in relatively straight arteries (e.g., the abdominal aorta) subjected to hypertension.