Two-Dimensional Stress-Strain Relationship for Canine Pericardium

Abstract

Two-dimensional pseudoelastic mechanical properties of the canine pericardium were investigated in vitro. The pericardium was assumed to be orthotropic. The material symmetry axis was determined a priori and aligned with the stretching axis. Various biaxial stretching tests were then performed and a set of data covering a wide range of strains was constructed. This complete data set was fitted to a new exponential type constitutive model, and a set of true material constants was determined for each specimen. Using the constitutive model and the true material constants, the results from constant lateral force tests and constant lateral displacement tests were predicted and compared with experiment.

Initiation of aneurysms as a mechanical bifurcation phenomenon

“…Using the single-layer model proposed by Choi and Vito [26], with material parameters given by Vande Geest et al [6] for healthy human aortic arteries, we have demonstrated that bifurcation can be induced by geometrical and material imperfections. This is consistent with the established view that localized weakening of collagen fibres serves as a precursor to aneurysm formation.…”

“…They fitted their experimental data to the following strain-energy function proposed by Choi and Vito's [26]: 4) where the b's are material constants and the E's are the components of the Green-Lagrange strain tensor E = (C − I)/2 referred to cylindrical polar coordinates (r, θ, z) in the reference configuration. They gave 8 sets of parameter values for healthy abdominal aorta tissues.…”

“…The first is the multi-layer structural model of Holzapfel et al [25] which also gives material parameter data for carotid arteries of a young rabbit. The second is the single-layer arterial model proposed by Choi and Vito [26] with data provided by Vande Geest et al [6] for a group of healthy but elderly human aortic arteries. It is known that aneurysms are rare in animals and more so among young animals, and that aneurysms can be induced by pathological changes in elderly humans.…”

Biomechanics and FE Modelling of Aneurysm: Review and Advances in Computational Models

“…The phenomenological approach is commonly used but has led to a number of difficulties in describing the mechanical behavior of tissues. Among phenomenological SEFs, Vande Geest and co-authors [77] found that a constitutive functional form used earlier by Choi and Vito [12], Equation 7, would best suit their experimental data:…”

A bilinear stress–strain relationship for arteries

“…Interestingly, Choi and Vito [22] proposed a strain energy density function for canine pericardium (also see [13]) of the form: (12) where b 's are material constants. Since the role of parameter b 0 in the above equation (or constant C in Fung's model [12]) is a scale factor, Eq.…”