title: Physical invariant strain energy function for passive myocardium.
abstract: Principal axis formulations are regularly used in isotropic elasticity, but they are not often used in dealing with anisotropic problems. In this paper, based on a principal axis technique, we develop a physical invariant orthotropic constitutive equation for incompressible solids, where it contains only a one variable (general) function. The corresponding strain energy function depends on six invariants that have immediate physical interpretation. These invariants are useful in facilitating an experiment to obtain a specific constitutive equation for a particular type of materials. The explicit appearance of the classical ground-state constants in the constitutive equation simplifies the calculation for their admissible values. A specific constitutive model is proposed for passive myocardium, and the model fits reasonably well with existing simple shear and biaxial experimental data. It is also able to predict a set of data from a simple shear experiment.
authors.affiliation: Department of Applied Mathematics and Science, Khalifa University of Science, Technology and Research, Sharjah, UAE. shariff@kustar.ac.ae
authors.forename: M H B M
authors.initials: MH
authors.lastname: Shariff
mesh_terms: D001696:Biomechanical Phenomena / Q000502:physiology; D006801:Humans; D008955:Models, Cardiovascular; D009206:Myocardium / Q000378:metabolism*