Although many researchers have made the assumption that the abdominal aortic aneurysm (AAA) wall behaves as an incompressible and isotropic material, the experimental evidence for it is insufficient. Hence, the assumptions about the incompressibility and isotropy of the AAA wall were verified through analysis of stretch ratios of samples excised from the aneurysms walls. The stretch ratios were...

Many problems concerned with the mathematical treatment of fourth-order tensors still remain open in the literature. In the present paper they will be considered in the framework of a complete theory involving a set of notations and de®nitions, a tensor operation algebra, di€erentiation rules, eigenvalue problems, applications of fourth-order tensors to isotropic tensor functions and some other...

In order to accelerate implementation of hyperelastic materials for finite element analysis, we developed an automatic numerical algorithm that only requires the strain energy function. This saves the effort on analytical derivation and coding of stress and tangent modulus, which is time-consuming and prone to human errors. Using the one-sided Newton difference quotients, the proposed algorithm...

Cardiac muscle tissue during relaxation is commonly modeled as a hyperelastic material with strongly nonlinear and anisotropic stress response. Adapting the behavior of such a model to experimental or patient data gives rise to a parameter estimation problem which involves a significant number of parameters. Gradient-based optimization algorithms provide a way to solve such nonlinear parameter ...

The uniform convergence of finite element approximations based on a modified Hu-Washizu formulation for the nearly incompressible linear elasticity is analyzed. We show the optimal and robust convergence of the displacement-based discrete formulation in the nearly incompressible case with the choice of approximations based on quadrilateral and hexahedral elements. These choices include bases th...

All the human blood vessels are surrounded by adipose tissue. Therefore in biomechanics of blood vessels, it is important to deal not only with the constitutive modelling of blood vessels as such but also with the mechanical properties of surrounding tissue. In this study, mechanical response of human perivascular adipose tissue that surrounds the abdominal aorta is concerned. From the performe...

We present a continuum model for the mechanical behavior of the skeletal muscle tissue when its functionality is reduced due to aging. The loss of ability of activating is typical of the geriatric syndrome called sarcopenia. The material is described by a hyperelastic, polyconvex, transverse isotropic strain energy function. The three material parameters appearing in the energy are fitted by le...

This paper aims at describing an inflation test protocol on a human liver capsule using stereo-correlation. The biaxial tension created by the inflation test is comparable to the type of loading the capsule would be subjected to during a liver compression. Confocal microscopy associated to an anti-collagen coloration reveals that the tissue is isotropic at the meso-scale. Stereo-correlation pro...

Equations governing the flow of fluid containing visco-hyperelastic particles are developed in an Eulerian framework. The novel feature introduced here is to write an evolution equation for the strain. It is envisioned that this will simplify numerical codes which typically compute the strain on Lagrangian meshes moving through Eulerian meshes. Existence results for the flow of linear visco-hyp...