An evaluation of pseudoelastic descriptors used in arterial mechanics

Understanding how transmural distributions of stress relate to the mechanisms of vascular growth, remodeling, and disease necessitates computations that are based on a constitutive relation for the arterial wall. Although a number of candidate relations are in the literature, they have not been compared in detail. In this note, three commonly used descriptors of the passive behavior of common carotid arteries are compared using simple "thought experiments." It is shown that two of the three relations are inherently limited in the degree of anisotropy they allow,that each predicts a different anisotropy, and that one yields physically unrealistic predictions given many of the published values of the material parameters. Based on this comparison, it appears that the relation proposed by Chuong and Fung is the best available, though there may be a need to search for an alternate form, particularly for muscular arteries. The methods presented herein are offered as a guide to help the experimentalist identify alternative forms of pseudostrain-energy functions for arteries.