PREDICTION OF PLANAR UNIAXIAL AND CONSTRAINED BIAXIAL STATE OF DEFORMATION BY COMMONLY USED ANISOTROPIC CONSTITUTIVE MODELS IN ARTERIAL MECHANICS
 
D. Veljković, M. Kojić
 
Abstract
 
In this paper is investigated mechanical response of tissue strips under planar simple tension
and constrained biaxial tension (strain behavior by Humprey) for a representative selection of
two- and three-dimensional anisotropic strain energy functions, commonly used in arterial
mechanics: Fung’s 2D and 3D models, logarithmic, polynomial and exponential Choi and Vito
2D models, and structural exponential 3D model for artery layers. It has shown that all these
models have limitations in capability of describing the considered states of deformation. By
using material parameters from literature it was found that there are a considerable number of
cases where unrealistic material response might be predicted, if the parameters are outside of
the range for which fitting process was performed. In order to avoid instability of computed
material response, we suggest that uniaxial loading conditions should be considered, together
with constrained biaxial tension, in experimental investigations for establishing new material
model or fitting constants of a selected model.