A finite element study of invariant-based orthotropic constitutive equations in the context of myocardial material parameter estimation.
A previous study investigated a number of invariant-based orthotropic and transversely isotropic constitutive equations for their suitability to fit three-dimensional simple shear mechanics data of passive myocardial tissue. The study was based on the assumption of a homogeneous deformation. Here, we extend the previous study by performing an inverse finite element material parameter estimation. This ensures a more realistic deformation state and material parameter estimates. The constitutive relations were compared on the basis of (i) 'goodness of fit': how well they fit a set of six shear deformation tests and (ii) 'variability': how well determined the material parameters are over the range of experiments. These criteria were utilised to discuss the advantages and disadvantages of the constitutive relations. It was found that a specific form of the polyconvex type as well as the exponential Fung-type equations were most suitable for modelling the orthotropic behaviour of myocardium under simple shear.
Schmid
H
H
Department of Continuum Mechanics, RWTH Aachen University, Aachen, Germany. schmid@km.rwth-aachen.de
Wang
W
W
Hunter
P J
PJ
Nash
M P
MP
D000818:Animals; D020342:Finite Element Analysis; D006321:Heart / Q000033:anatomy & histology*; D008962:Models, Theoretical; D013552:Swine